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Sample records for hydroxyapatite based bioactive

  1. Bioactivity and biocompatibility of hydroxyapatite-based bioceramic coatings on zirconium by plasma electrolytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Aktuğ, Salim Levent, E-mail: saktug@gtu.edu.tr [The Department of Materials Science and Engineering, Gebze Technical University, Gebze, Kocaeli 41400 (Turkey); Durdu, Salih, E-mail: durdusalih@gmail.com [The Department of Industrial Engineering, Giresun University, Merkez, Giresun 28200 (Turkey); Yalçın, Emine, E-mail: emine.yalcin@giresun.edu.tr [The Department of Biology, Giresun University, Merkez, Giresun 28200 (Turkey); Çavuşoğlu, Kültigin, E-mail: kultigin.cavusoglu@giresun.edu.tr [The Department of Biology, Giresun University, Merkez, Giresun 28200 (Turkey); Usta, Metin, E-mail: ustam@gtu.edu.tr [The Department of Materials Science and Engineering, Gebze Technical University, Gebze, Kocaeli 41400 (Turkey); Materials Institute, Marmara Research Center, TUBITAK, Gebze, Kocaeli 41470 (Turkey)

    2017-02-01

    In the present work, hydroxyapatite (HAP)-based plasma electrolytic oxide (PEO) coatings were produced on zirconium at different current densities in a solution containing calcium acetate and β-calcium glycerophosphate by a single step. The phase structure, surface morphology, functional groups, thickness and roughness of the coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), eddy current method and surface profilometer, respectively. The phases of cubic-zirconia, calcium zirconate and HAP were detected by XRD. The amount of HAP and calcium zirconate increased with increasing current density. The surface of the coatings was very porous and rough. Moreover, bioactivity and biocompatibility of the coatings were analyzed in vitro immersion simulated body fluid (SBF) and MTT (3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyl tetrazolium bromide) assay, hemolysis assay and bacterial formation. The apatite-forming ability of the coatings was evaluated after immersion in SBF up to 28 days. After immersion, the bioactivity of HAP-based coatings on zirconium was greater than the ones of uncoated zirconium and zirconium oxide-based surface. The bioactivity of PEO surface on zirconium was significantly improved under SBF conditions. The bacterial adhesion of the coatings decreased with increasing current density. The bacterial adhesion of the coating produced at 0.370 A/cm{sup 2} was minimum compared to uncoated zirconium coated at 0.260 and 0.292 A/cm{sup 2}. The hemocompatibility of HAP-based surfaces was improved by PEO. The cell attachment and proliferation of the PEO coatings were better than the one of uncoated zirconium according to MTT assay results. - Highlights: • Hydroxyapatite was formed on zirconium at different current densities by single-step plasma electrolytic oxidation. • The amount of hydroxyapatite and calcium-based phases increased with

  2. Hydroxyapatite-chitosan based bioactive hybrid biomaterials with improved mechanical strength

    Science.gov (United States)

    Zima, A.

    2018-03-01

    Composites consisting of hydroxyapatite (HA) and chitosan (CTS) have recently been intensively studied. In this work, a novel inorganic-organic (I/O) HA/CTS materials in the form of granules were prepared through a simple solution-based chemical method. During the synthesis of these hybrids, the electrostatic complexes between positively charged, protonated amine groups of chitosan and the negative phosphate species (HPO42 - and H2PO4-) were formed. Our biocomposites belong to the class I of hybrids, which was confirmed by FTIR studies. XRD analysis revealed that the obtained materials consisted of hydroxyapatite as the only crystalline phase. Homogeneous dispersion of the components in HA/CTS composites was confirmed. The use of 17 wt% and 23 wt% of chitosan resulted in approximately 12-fold and 16-fold increase in the compressive strength of HA/CTS as compared to the non-modified HA material. During incubation of the studied materials in SBF, pH of the solution remained close to the physiological one. Formation of apatite layer on their surfaces indicated bioactive nature of the developed biomaterials.

  3. Bioactivity and biocompatibility of hydroxyapatite-based bioceramic coatings on zirconium by plasma electrolytic oxidation.

    Science.gov (United States)

    Aktuğ, Salim Levent; Durdu, Salih; Yalçın, Emine; Çavuşoğlu, Kültigin; Usta, Metin

    2017-02-01

    In the present work, hydroxyapatite (HAP)-based plasma electrolytic oxide (PEO) coatings were produced on zirconium at different current densities in a solution containing calcium acetate and β-calcium glycerophosphate by a single step. The phase structure, surface morphology, functional groups, thickness and roughness of the coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), eddy current method and surface profilometer, respectively. The phases of cubic-zirconia, calcium zirconate and HAP were detected by XRD. The amount of HAP and calcium zirconate increased with increasing current density. The surface of the coatings was very porous and rough. Moreover, bioactivity and biocompatibility of the coatings were analyzed in vitro immersion simulated body fluid (SBF) and MTT (3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyl tetrazolium bromide) assay, hemolysis assay and bacterial formation. The apatite-forming ability of the coatings was evaluated after immersion in SBF up to 28days. After immersion, the bioactivity of HAP-based coatings on zirconium was greater than the ones of uncoated zirconium and zirconium oxide-based surface. The bioactivity of PEO surface on zirconium was significantly improved under SBF conditions. The bacterial adhesion of the coatings decreased with increasing current density. The bacterial adhesion of the coating produced at 0.370A/cm 2 was minimum compared to uncoated zirconium coated at 0.260 and 0.292A/cm 2 . The hemocompatibility of HAP-based surfaces was improved by PEO. The cell attachment and proliferation of the PEO coatings were better than the one of uncoated zirconium according to MTT assay results. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. In vivo performance of novel soybean/gelatin-based bioactive and injectable hydroxyapatite foams.

    Science.gov (United States)

    Kovtun, Anna; Goeckelmann, Melanie J; Niclas, Antje A; Montufar, Edgar B; Ginebra, Maria-Pau; Planell, Josep A; Santin, Matteo; Ignatius, Anita

    2015-01-01

    Major limitations of calcium phosphate cements (CPCs) are their relatively slow degradation rate and the lack of macropores allowing the ingrowth of bone tissue. The development of self-setting cement foams has been proposed as a suitable strategy to overcome these limitations. In previous work we developed a gelatine-based hydroxyapatite foam (G-foam), which exhibited good injectability and cohesion, interconnected porosity and good biocompatibility in vitro. In the present study we evaluated the in vivo performance of the G-foam. Furthermore, we investigated whether enrichment of the foam with soybean extract (SG-foam) increased its bioactivity. G-foam, SG-foam and non-foamed CPC were implanted in a critical-size bone defect in the distal femoral condyle of New Zealand white rabbits. Bone formation and degradation of the materials were investigated after 4, 12 and 20weeks using histological and biomechanical methods. The foams maintained their macroporosity after injection and setting in vivo. Compared to non-foamed CPC, cellular degradation of the foams was considerably increased and accompanied by new bone formation. The additional functionalization with soybean extract in the SG-foam slightly reduced the degradation rate and positively influenced bone formation in the defect. Furthermore, both foams exhibited excellent biocompatibility, implying that these novel materials may be promising for clinical application in non-loaded bone defects. Copyright © 2014 Acta Materialia Inc. All rights reserved.

  5. Microstructures, hardness and bioactivity of hydroxyapatite coatings

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2014-10-01

    Full Text Available Hydroxyapatite (HAP) coatings on bioinert metals such as Ti–6Al–4V are necessary for biomedical applications. Together, HAP and Ti–6Al–4V are biocompatible and bioactive. The challenges of depositing HAP on Ti–6Al–4V with traditional thermal...

  6. Bioactive polyurethane implants with hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Rozhnova, R.; Kebuladze, I.; Galatenko, N. [NAS Ukraine, Kiev (Ukraine). Dept. of Polymers of Medical Appointment

    2001-07-01

    Biologically active polyurethane compositions for plastic of bone defects that contain bioceramic - hydroxyapatite (HAP) and immunomodulator - levamisole (LEV) were designed. The influence of the biologically active fillers in structure polyurethane compositions on their physical and chemical properties in condition in vivo by method of Equilibrium Swelling, method of IR-spectroscopy, roentgen-structural analysis was studied. The introduce in structure of the biodegraded polymeric matrix of HAP is established to promote accumulation of the inorganic component of bone tissue in vivo which is being by basis of the bone formation in regenerating tissue. (orig.)

  7. A one-step method to fabricate PLLA scaffolds with deposition of bioactive hydroxyapatite and collagen using ice-based microporogens

    Science.gov (United States)

    Li, Jiashen; Chen, Yun; Mak, Arthur F.T.; Tuan, Rocky S.; Li, Lin; Li, Yi

    2010-01-01

    Porous poly(L-lactic acid) (PLLA) scaffolds with bioactive coatings were prepared by a novel one-step method. In this process, ice-based microporogens containing bioactive molecules, such as hydroxyapatite (HA) and collagen, served as both porogens to form the porous structure and vehicles to transfer the bioactive molecules to the inside of PLLA scaffolds in a single step. Based on scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis, the bioactive components were found to be transferred successfully from the porogens to PLLA scaffolds evenly. Osteoblast cells were used to evaluate the cellular behaviors of the composite scaffolds. After 8 days culturing, MTT assay and alkaline phosphatase (ALP) activity results suggested that HA/collagen could improve the interactions between osteoblast cells and the polymeric scaffold. PMID:20004261

  8. Development of a composite based on hydroxyapatite and magnesium and zinc‐containing sol–gel-derived bioactive glass for bone substitute applications

    International Nuclear Information System (INIS)

    Ashuri, Maziar; Moztarzadeh, Fathollah; Nezafati, Nader; Ansari Hamedani, Ali; Tahriri, Mohammadreza

    2012-01-01

    In the present study, a bioceramic-based composite was prepared by sintering compacts made up of mixtures of hydroxyapatite (HA) and sol–gel-derived bioactive glass (64SiO 2 -26CaO-5MgO-5ZnO) (based on mol%) powders. HA powder was mixed with different concentrations of the glass powders up to 30 wt.%. The effect of adding bioactive glass powder to HA matrix, on the mechanical properties of the composite was assessed by compression test. The specimen with the highest compressive strength was chosen to be immersed in simulated body fluid (SBF) to study apatite forming ability and dissolution behavior. It was found that compressive strength of the specimen was decreased 65% after maintaining in the SBF for 14 days. X-ray diffraction (XRD) showed prevalence of HA and β-TCP related peaks. Also, the surface morphology of the composite was observed using scanning electron microscopy (SEM). The study of degradation behavior revealed Si release capability of this composite. Biological evaluations in vitro confirmed the composite studied could induce osteoblast-like cells' activities. - Highlights: ► A novel composite based on HA/bioactive glass for bone substitutes was developed. ► Evaluations in vitro confirmed the composites induce bone-like cells' activities. ► A successful compromise of bioactivity and cytocompatibility was observed.

  9. Characterization,Mechanical, and In Vitro Bioactivity Properties of Hydroxyapatite/Bioactive Glass Composite

    Directory of Open Access Journals (Sweden)

    Israa Kahatan Sabree

    2016-12-01

    Full Text Available Bioactive ceramic materials can help bone reparation and regeneration by offering support to bone growth. Biological hydroxyapatite powder was prepared by burning animal bone followed by studying the mechanical properties of hydroxyapatite (HA/ (20wt.%, and 40wt.% of binary bioactive glass (70% SiO2- 30% CaO in order to evaluate the influence of composition on the compressive strength and hardness. HA-composite material exhibited increasing density, microhardness, and compressive strength with increasing amount of glass addition. X-ray diffraction after sintering at 1200°C showed no alter of HA to secondary phases while the hydroxyapatite/ bioactive glass composites contained a HA phase and different amounts of wollastonite phase, depending on the amount of bioglass added. In vitro tests, the samples were soaked in simulated body fluid (SBF for ten days in order to evaluate the change in compression strength, weight loss, and pH. The HA composite reinforced with 40 wt % bioglass showed highest compression strength, and lowest weight loss

  10. Bioactive glass/hydroxyapatite composites: mechanical properties and biological evaluation.

    Science.gov (United States)

    Bellucci, Devis; Sola, Antonella; Anesi, Alexandre; Salvatori, Roberta; Chiarini, Luigi; Cannillo, Valeria

    2015-06-01

    Bioactive glass/hydroxyapatite composites for bone tissue repair and regeneration have been produced and discussed. The use of a recently developed glass, namely BG_Ca/Mix, with its low tendency to crystallize, allowed one to sinter the samples at a relatively low temperature thus avoiding several adverse effects usually reported in the literature, such as extensive crystallization of the glassy phase, hydroxyapatite (HA) decomposition and reaction between HA and glass. The mechanical properties of the composites with 80wt.% BG_Ca/Mix and 20wt.% HA are sensibly higher than those of Bioglass® 45S5 reference samples due to the presence of HA (mechanically stronger than the 45S5 glass) and to the thermal behaviour of the BG_Ca/Mix, which is able to favour the sintering process of the composites. Biocompatibility tests, performed with murine fibroblasts BALB/3T3 and osteocites MLO-Y4 throughout a multi-parametrical approach, allow one to look with optimism to the produced composites, since both the samples themselves and their extracts do not induce negative effects in cell viability and do not cause inhibition in cell growth. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Synthesis and characterization of TEP-EDTA-regulated bioactive hydroxyapatite

    Science.gov (United States)

    Haders, Daniel Joseph, II

    Hydroxyapatite (HA), Ca10(PO4)6(OH) 2, the stoichiometric equivalent of the ceramic phase of bone, is the preferred material for hard tissue replacement due to its bioactivity. However, bioinert metals are utilized in load-bearing orthopedic applications due to the poor mechanical properties of HA. Consequently, attention has been given to HA coatings for metallic orthopedic implants to take advantage of the bioactivity of HA and the mechanical properties of metals. Commercially, the plasma spray process (PS-HA) is the method most often used to deposit HA films on metallic implants. Since its introduction in the 1980's, however, concerns have been raised about the consequences of PS-HA's low crystallinity, lack of phase purity, lack of film-substrate chemical adhesion, passivation properties, and difficulty in coating complex geometries. Thus, there is a need to develop inexpensive reproducible next-generation HA film deposition techniques, which deposit high crystallinity, phase pure, adhesive, passivating, conformal HA films on clinical metallic substrates. The aim of this dissertation was to intelligently synthesize and characterize the material and biological properties of HA films on metallic substrates synthesized by hydrothermal crystallization, using thermodynamic phase diagrams as the starting point. In three overlapping interdisciplinary studies the potential of using ethylenediamine-tetraacetic acid/triethyl phosphate (EDTA/TEP) doubly regulated hydrothermal crystallization to deposit HA films, the TEP-regulated, time-and-temperature-dependent process by which films were deposited, and the bioactivity of crystallographically engineered films were investigated. Films were crystallized in a 0.232 molal Ca(NO3)2-0.232 molal EDTA-0.187 molal TEP-1.852 molal KOH-H2O chemical system at 200°C. Thermodynamic phase diagrams demonstrated that the chosen conditions were expected to produce Ca-P phase pure HA, which was experimentally confirmed. EDTA regulation of

  12. Influence of pentavalent dopant addition to polarization and bioactivity of hydroxyapatite

    International Nuclear Information System (INIS)

    Dhal, Jharana; Bose, Susmita; Bandyopadhyay, Amit

    2013-01-01

    Influence of pentavalent tantalum doping in bulk hydroxyapatite (HAp) ceramics has been investigated for polarizability and bioactivity. Phase analysis from X-ray diffraction measurement indicates that increasing dopant concentration decreased the amount of HAp phase and increased β-TCP and/or α-TCP phases during sintering at 1250 °C in a muffle furnace. Results from thermally stimulated depolarization current (TSDC) measurements showed that doping hindered charge storage ability in HAp ceramics, and doped samples stored fewer charge compared to pure HAp. However, doping enhanced wettability of HAp samples, which was improved further due to polarization. In vitro human osteoblast cell–material interaction study revealed an increase in bioactivity due to dopant addition and polarization compared to pure HAp. This increase in bioactivity was attributed to the increase in wettability due to surface charge and dopant addition. - Highlights: • Tantalum doping makes HAp unstable during sintering at 1250 °C and forms TCP. • Tantalum doping reduces charge storage ability of HAp ceramics. • Even with lower charge storage ability tantalum doping improves wettability. • Tantalum doping enhances bioactivity of calcium phosphate based sintered compacts

  13. Bioactivity of thermal plasma synthesized bovine hydroxyapatite/glass ceramic composites

    International Nuclear Information System (INIS)

    Yoganand, C P; Selvarajan, V; Rouabhia, Mahmoud; Cannillo, Valeria; Sola, Antonella

    2010-01-01

    Bone injuries and failures often require the inception of implant biomaterials. Research in this area is receiving increasing attention worldwide. A variety of artificial bone materials, such as metals, polymeric materials, composites and ceramics, are being explored to replace diseased bones. Calcium phosphate ceramics are currently used as biomaterials for many applications in both dentistry and orthopedics. Bioactive silicate-based glasses show a higher bioactive behaviour than calcium phosphate materials. It is very interesting to study the mixtures of HA and silicate-based glasses. In the present study; natural bovine hydroxyapatite / SiO 2 -CaO-MgO glass composites were produced using the Transferred arc plasma (TAP) melting method. TAP melting route is a brisk process of preparation of glass-ceramics in which the raw materials are melted in the plasma and crystallization of the melt occurs while cooling down at a much faster rate in relatively short processing times compared to the conventional methods of manufacture of glass ceramics/composites. It is well known that; one essential step to the understanding of the biological events occurring at the bone tissue/material interface is the biological investigation by in vitro tests. Cell lines are commonly used for biocompatibility tests, and are very efficient because of their reproducibility and culture facility. In this study, we report the results of a study on the response of primary cultures of human fibroblast cells to TAP melted bioactive glass ceramics.

  14. Nano-Hydroxyapatite/Fluoridated and Unfluoridated Bioactive Glass Composites: Structural Analysis and Bioactivity Evaluation

    International Nuclear Information System (INIS)

    Batra, Uma; Kapoor, Seema; Sharma, J. D.

    2011-01-01

    Biphasic bioceramic composites containing nano-hydroxyapatite (HAP) and nanosized bioactive glasses have been prepared in the form of pellets and have been examined for the effects of bioglass concentrations and sintering temperature on the structural transformations and bioactivity behavior. Pure stoichiometric nano-HAP was synthesized using sol-gel technique. Two bioglasses synthesized in this work--fluoridated bioglass (Cao-P 2 O 5 -Na 2 O 3 -CaF 2 ) and unfluoridated bioglass (Cao-P 2 O 5 -Na 2 O 3 ) designated as FBG and UFBG respectively, were added to nano-HAP with concentrations of 5, 10, 12 and 15%. The average particle sizes of synthesized HAP and bioglasses were 23 nm and 35 nm, respectively. The pellets were sintered at four different temperatures i.e. 1000 deg. C, 1150 deg. C, 1250 deg. C and 1350 deg. C. The investigations involved study of structural and bioactivity behavior of green and sintered pellets and their deviations from original materials i.e. HAP, FBG and UFBG, using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The phase composition of the sintered pellets was found to be non-stoichiometric HAP with α-TCP (tricalcium phosphate) and β-TCP. It was revealed from SEM images that bonding mechanism was mainly solid state sintering for all pellets sintered at 1000 deg. C and 1150 deg. C and also for pellets with lower concentrations of bioglass i.e. 5% and 10% sintered at 1250 deg. C. Partly liquid phase sintering was observed for pellets with higher bioglass concentrations of 12% and 15% sintered at 1250 deg. C and same behaviour was noted for pellets at all concentrations of bioglasses at 1350 deg. C. The sintered density, hardness and compression strength of pellets have been influenced both by the concentration of the bioglasses and sintering temperature. It was observed that the biological HAP layer formation was faster on the green pellets surface than on pure HAP and sintered pellets, showing higher bioactivity in the

  15. Bioactivity of cellulose acetate/hydroxyapatite nanoparticle composite fiber by an electro-spinning process.

    Science.gov (United States)

    Kwak, Dae Hyun; Lee, Eun Ju; Kim, Deug Joong

    2014-11-01

    Hydroxyapatite/cellulose acetate composite webs were fabricated by an electro-spinning process. This electro-spinning process makes it possible to fabricate complex three-dimensional shapes. Nano fibrous web consisting of cellulose acetate and hydroxyapatite was produced from their mixture solution by using an electro-spinning process under high voltage. The surface of the electro-spun fiber was modified by a plasma and alkaline solution in order to increase its bioactivity. The structure, morphology and properties of the electro-spun fibers were investigated and an in-vitro bioactivity test was evaluated in simulated body fluid (SBF). Bioactivity of the electro-spun web was enhanced with the filler concentration and surface treatment. The surface changes of electro-spun fibers modified by plasma and alkaline solution were investigated by FT-IR (Fourier Transform Infrared Spectroscopy) and XPS (X-ray Photoelectron Spectroscopy).

  16. Research on the preparation, biocompatibility and bioactivity of magnesium matrix hydroxyapatite composite material.

    Science.gov (United States)

    Linsheng, Li; Guoxiang, Lin; Lihui, Li

    2016-08-12

    In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity.

  17. Bioactivity and osteointegration of hydroxyapatite-coated stainless steel and titanium wires used for intramedullary osteosynthesis.

    Science.gov (United States)

    Popkov, Arnold V; Gorbach, Elena N; Kononovich, Natalia A; Popkov, Dmitry A; Tverdokhlebov, Sergey I; Shesterikov, Evgeniy V

    2017-08-01

    A lot of research was conducted on the use of various biomaterials in orthopedic surgery. Our study investigated the effects of nanostructured calcium-phosphate coating on metallic implants introduced into the bone marrow canal. Stainless steel or titanium 2-mm wires (groups 1 and 2, respectively), and hydroxyapatite-coated stainless steel or titanium wires of the same diameter (groups 3 and 4, respectively) were introduced into the tibial bone marrow canal of 20 dogs (each group = 5 dogs). Hydroxyapatite coating was deposited on the wires with the method of microarc oxidation. Light microscopy to study histological diaphyseal transverse sections, scanning electron microscopy to study the bone marrow area around the implant and an X-ray electron probe analyzer to study the content of calcium and phosphorus were used to investigate bioactivity and osteointegration after a four weeks period. Osteointegration was also assessed by measuring wires' pull-off strength with a sensor dynamometer. Bone formation was observed round the wires in the bone marrow canal in all the groups. Its intensity depended upon the features of wire surfaces and implant materials. Maximum percentage volume of trabecular bone was present in the bone marrow canals of group 4 dogs that corresponded to a mean of 27.1 ± 0.14%, while it was only 6.7% in group 1. The coating in groups 3 and 4 provided better bioactivity and osteointegration. Hydroxyapatite-coated titanium wires showed the highest degree of bone formation around them and greater pull-off strength. Nanostructured hydroxyapatite coating of metallic wires induces an expressed bone formation and provides osteointegration. Hydroxyapatite-coated wires could be used along with external fixation for bone repair enhancement in diaphyseal fractures, management of osteogenesis imperfecta and correction of bone deformities in phosphate diabetes.

  18. Synthesis, bioactivity and zeta potential investigations of chlorine and fluorine substituted hydroxyapatite

    International Nuclear Information System (INIS)

    Fahami, Abbas; Beall, Gary W.; Betancourt, Tania

    2016-01-01

    Chlorine and fluorine substituted hydroxyapatites (HA-Cl–F) with different degrees of ion replacement were successfully prepared by the one step mechanochemical activation method. X-ray diffraction (XRD) and FT-IR spectra indicated that substitution of these anions in milled powders resulted in the formation of pure hydroxyapatite phase except for the small observed change in the lattice parameters and unit cell volumes of the resultant hydroxyapatite. Microscopic observations showed that the milled product had a cluster-like structure made up of polygonal and spherical particles with an average particle size of approximately ranged from 20 ± 5 to 70 ± 5 nm. The zeta potential of milled samples was performed at three different pH (5, 7.4, and 9). The obtained zeta potential values were negative for all three pH values. Negative zeta potential was described to favor osseointegration, apatite nucleation, and bone regeneration. The bioactivity of samples was investigated on sintered pellets soaked in simulated body fluid (SBF) solution and apatite crystals formed on the surface of the pellets after being incubated for 14 days. Zeta potential analysis and bioactivity experiment suggested that HA-Cl–F will lead to the formation of new apatite particles and therefore be a potential implant material. - Highlights: • Cl"− and F"− substituted hydroxyapatite was synthesized by mechanochemical process. • Structural features were influenced strongly by incorporation of different ions. • Microscopic observations showed a mean particle size of around 20 ± 5 to 70 ± 5 nm. • The bioactivity properties indicated that apatite was successfully formed.

  19. Synthesis, bioactivity and zeta potential investigations of chlorine and fluorine substituted hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Fahami, Abbas, E-mail: fahami@txstate.edu [Materials Science, Engineering and Commercialization Program, Texas State University, San Marcos, TX 78666 (United States); Beall, Gary W. [Department of Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX 78666 (United States); Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Betancourt, Tania [Materials Science, Engineering and Commercialization Program, Texas State University, San Marcos, TX 78666 (United States); Department of Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX 78666 (United States)

    2016-02-01

    Chlorine and fluorine substituted hydroxyapatites (HA-Cl–F) with different degrees of ion replacement were successfully prepared by the one step mechanochemical activation method. X-ray diffraction (XRD) and FT-IR spectra indicated that substitution of these anions in milled powders resulted in the formation of pure hydroxyapatite phase except for the small observed change in the lattice parameters and unit cell volumes of the resultant hydroxyapatite. Microscopic observations showed that the milled product had a cluster-like structure made up of polygonal and spherical particles with an average particle size of approximately ranged from 20 ± 5 to 70 ± 5 nm. The zeta potential of milled samples was performed at three different pH (5, 7.4, and 9). The obtained zeta potential values were negative for all three pH values. Negative zeta potential was described to favor osseointegration, apatite nucleation, and bone regeneration. The bioactivity of samples was investigated on sintered pellets soaked in simulated body fluid (SBF) solution and apatite crystals formed on the surface of the pellets after being incubated for 14 days. Zeta potential analysis and bioactivity experiment suggested that HA-Cl–F will lead to the formation of new apatite particles and therefore be a potential implant material. - Highlights: • Cl{sup −} and F{sup −} substituted hydroxyapatite was synthesized by mechanochemical process. • Structural features were influenced strongly by incorporation of different ions. • Microscopic observations showed a mean particle size of around 20 ± 5 to 70 ± 5 nm. • The bioactivity properties indicated that apatite was successfully formed.

  20. Synthesis, bioactivity and zeta potential investigations of chlorine and fluorine substituted hydroxyapatite.

    Science.gov (United States)

    Fahami, Abbas; Beall, Gary W; Betancourt, Tania

    2016-02-01

    Chlorine and fluorine substituted hydroxyapatites (HA-Cl-F) with different degrees of ion replacement were successfully prepared by the one step mechanochemical activation method. X-ray diffraction (XRD) and FT-IR spectra indicated that substitution of these anions in milled powders resulted in the formation of pure hydroxyapatite phase except for the small observed change in the lattice parameters and unit cell volumes of the resultant hydroxyapatite. Microscopic observations showed that the milled product had a cluster-like structure made up of polygonal and spherical particles with an average particle size of approximately ranged from 20±5 to 70±5nm. The zeta potential of milled samples was performed at three different pH (5, 7.4, and 9). The obtained zeta potential values were negative for all three pH values. Negative zeta potential was described to favor osseointegration, apatite nucleation, and bone regeneration. The bioactivity of samples was investigated on sintered pellets soaked in simulated body fluid (SBF) solution and apatite crystals formed on the surface of the pellets after being incubated for 14days. Zeta potential analysis and bioactivity experiment suggested that HA-Cl-F will lead to the formation of new apatite particles and therefore be a potential implant material. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Tunable Degradation Rate and Favorable Bioactivity of Porous Calcium Sulfate Scaffolds by Introducing Nano-Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Jianhua Zhou

    2016-12-01

    Full Text Available The bone scaffolds should possess suitable physicochemical properties and osteogenic activities. In this study, porous calcium sulfate (CaSO4 scaffolds were fabricated successfully via selected laser sintering (SLS. Nano-hydroxyapatite (nHAp, a bioactive material with a low degradation rate, was introduced into CaSO4 scaffolds to overcome the overquick absorption. The results demonstrated that nHAp could not only control the degradation rate of scaffolds by adjusting their content, but also improve the pH environment by alleviating the acidification progress during the degradation of CaSO4 scaffolds. Moreover, the improved scaffolds were covered completely with the apatite spherulites in simulated body fluid (SBF, showing their favorable bioactivity. In addition, the compression strength and fracture toughness were distinctly enhanced, which could be ascribed to large specific area of nHAp and the corresponding stress transfer.

  2. Investigating the addition of SiO₂-CaO-ZnO-Na₂O-TiO₂ bioactive glass to hydroxyapatite: Characterization, mechanical properties and bioactivity.

    Science.gov (United States)

    Yatongchai, Chokchai; Placek, Lana M; Curran, Declan J; Towler, Mark R; Wren, Anthony W

    2015-11-01

    Hydroxyapatite (Ca10(PO4)6(OH)2) is widely investigated as an implantable material for hard tissue restoration due to its osteoconductive properties. However, hydroxyapatite in bulk form is limited as its mechanical properties are insufficient for load-bearing orthopedic applications. Attempts have been made to improve the mechanical properties of hydroxyapatite, by incorporating ceramic fillers, but the resultant composite materials require high sintering temperatures to facilitate densification, leading to the decomposition of hydroxyapatite into tricalcium phosphate, tetra-calcium phosphate and CaO phases. One method of improving the properties of hydroxyapatite is to incorporate bioactive glass particles as a second phase. These typically have lower softening points which could possibly facilitate sintering at lower temperatures. In this work, a bioactive glass (SiO2-CaO-ZnO-Na2O-TiO2) is incorporated (10, 20 and 30 wt%) into hydroxyapatite as a reinforcing phase. X-ray diffraction confirmed that no additional phases (other than hydroxyapatite) were formed at a sintering temperature of 560 ℃ with up to 30 wt% glass addition. The addition of the glass phase increased the % crystallinity and the relative density of the composites. The biaxial flexural strength increased to 36 MPa with glass addition, and there was no significant change in hardness as a function of maturation. The pH of the incubation media increased to pH 10 or 11 through glass addition, and ion release profiles determined that Si, Na and P were released from the composites. Calcium phosphate precipitation was encouraged in simulated body fluid with the incorporation of the bioactive glass phase, and cell culture testing in MC-3T3 osteoblasts determined that the composite materials did not significantly reduce cell viability. © The Author(s) 2015.

  3. Facilitated receptor-recognition and enhanced bioactivity of bone morphogenetic protein-2 on magnesium-substituted hydroxyapatite surface

    Science.gov (United States)

    Huang, Baolin; Yuan, Yuan; Li, Tong; Ding, Sai; Zhang, Wenjing; Gu, Yuantong; Liu, Changsheng

    2016-01-01

    Biomaterial surface functionalized with bone morphogenetic protein-2 (BMP-2) is a promising approach to fabricating successful orthopedic implants/scaffolds. However, the bioactivity of BMP-2 on material surfaces is still far from satisfactory and the mechanism of related protein-surface interaction remains elusive. Based on the most widely used bone-implants/scaffolds material, hydroxyapatite (HAP), we developed a matrix of magnesium-substituted HAP (Mg-HAP, 2.2 at% substitution) to address these issues. Further, we investigated the adsorption dynamics, BMPRs-recruitment, and bioactivity of recombinant human BMP-2 (rhBMP-2) on the HAP and Mg-HAP surfaces. To elucidate the mechanism, molecular dynamic simulations were performed to calculate the preferred orientations, conformation changes, and cysteine-knot stabilities of adsorbed BMP-2 molecules. The results showed that rhBMP-2 on the Mg-HAP surface exhibited greater bioactivity, evidenced by more facilitated BMPRs-recognition and higher ALP activity than on the HAP surface. Moreover, molecular simulations indicated that BMP-2 favoured distinct side-on orientations on the HAP and Mg-HAP surfaces. Intriguingly, BMP-2 on the Mg-HAP surface largely preserved the active protein structure evidenced by more stable cysteine-knots than on the HAP surface. These findings explicitly clarify the mechanism of BMP-2-HAP/Mg-HAP interactions and highlight the promising application of Mg-HAP/BMP-2 matrixes in bone regeneration implants/scaffolds. PMID:27075233

  4. Mechanical, Rheological, and Bioactivity Properties of Ultra High-Molecular-Weight Polyethylene Bioactive Composites Containing Polyethylene Glycol and Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Mazatusziha Ahmad

    2012-01-01

    Full Text Available Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50 phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P precipitates on the composite surface as proven from SEM and XRD analysis.

  5. Hydroxyapatite nanorod and microsphere functionalized with bioactive lactoferrin as a new biomaterial for enhancement bone regeneration.

    Science.gov (United States)

    Shi, Pujie; Wang, Qun; Yu, Cuiping; Fan, Fengjiao; Liu, Meng; Tu, Maolin; Lu, Weihong; Du, Ming

    2017-07-01

    Lactoferrin (LF) has been recently recognized as a promising new novel bone growth factor for the beneficial effects on bone cells and promotion of bone growth. Currently, it has been attracted wide attention in bone regeneration as functional food additives or a potential bioactive protein in bone tissue engineering. The present study investigated the possibility that hydroxyapatite (HAP) particles, a widely used bone substitute material for high biocompatibility and osteoconductivity, functionalized with lactoferrin as a composite material are applied to bone tissue engineering. Two kinds of hydroxyapatite samples with different sizes, including nanorods and microspheres particles, were functionalized with lactoferrin molecules, respectively. A detailed characterization of as-prepared HAP-LF complex is presented, combining thermal gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). Zeta potential and the analysis of electrostatic surface potential of lactoferrin were carried to reveal the mechanism of adsorption. The effects of HAP-LF complex on MC3T3-E1 osteoblast proliferation and morphology were systematically evaluated at different culture time. Interestingly, results showed that cell viability of HAP-LF group was significantly higher than HAP group indicating that the HAP-LF can improve the biocompatibility of HAP, which mainly originated from a combination of HAP-LF interaction. These results indicated that hydroxyapatite particles can work as a controlled releasing carrier of lactoferrin successfully, and lactoferrin showed better potentiality on using in the field of bone regeneration by coupling with hydroxyapatite. This study would provide a new biomaterial and might offer a new insight for enhancement of bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A new hydroxyapatite-based biocomposite for bone replacement

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, Devis, E-mail: devis.bellucci@unimore.it [Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Sola, Antonella [Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Gazzarri, Matteo; Chiellini, Federica [Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab) and UdR INSTM, Department of Chemistry and Industrial Chemistry, University of Pisa, Via Vecchia Livornese 1291, 56122S. Piero a Grado, Pisa (Italy); Cannillo, Valeria [Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy)

    2013-04-01

    Since the 1970s, various types of ceramic, glass and glass–ceramic materials have been proposed and used to replace damaged bone in many clinical applications. Among them, hydroxyapatite (HA) has been successfully employed thanks to its excellent biocompatibility. On the other hand, the bioactivity of HA and its reactivity with bone can be improved through the addition of proper amounts of bioactive glasses, thus obtaining HA-based composites. Unfortunately, high temperature treatments (1200 °C ÷ 1300 °C) are usually required in order to sinter these systems, causing the bioactive glass to crystallize into a glass–ceramic and hence inhibiting the bioactivity of the resulting composite. In the present study novel HA-based composites are realized and discussed. The samples can be sintered at a relatively low temperature (800 °C), thanks to the employment of a new glass (BG{sub C}a) with a reduced tendency to crystallize compared to the widely used 45S5 Bioglass®. The rich glassy phase, which can be preserved during the thermal treatment, has excellent effects in terms of in vitro bioactivity; moreover, compared to composites based on 45S5 Bioglass® having the same HA/glass proportions, the samples based on BG{sub C}a displayed an earlier response in terms of cell proliferation. - Highlights: ► New apatite/bioglass composites are proposed and sintered at low temperature. ► The samples' glassy phase is preserved and the apatite decomposition is avoided. ► The rich glassy phase in the samples results in an excellent bioactivity. ► The samples are able to support cell adhesion and proliferation. ► The samples support faster cell proliferation compared to 45S5Bioglass-composites.

  7. A new hydroxyapatite-based biocomposite for bone replacement

    International Nuclear Information System (INIS)

    Bellucci, Devis; Sola, Antonella; Gazzarri, Matteo; Chiellini, Federica; Cannillo, Valeria

    2013-01-01

    Since the 1970s, various types of ceramic, glass and glass–ceramic materials have been proposed and used to replace damaged bone in many clinical applications. Among them, hydroxyapatite (HA) has been successfully employed thanks to its excellent biocompatibility. On the other hand, the bioactivity of HA and its reactivity with bone can be improved through the addition of proper amounts of bioactive glasses, thus obtaining HA-based composites. Unfortunately, high temperature treatments (1200 °C ÷ 1300 °C) are usually required in order to sinter these systems, causing the bioactive glass to crystallize into a glass–ceramic and hence inhibiting the bioactivity of the resulting composite. In the present study novel HA-based composites are realized and discussed. The samples can be sintered at a relatively low temperature (800 °C), thanks to the employment of a new glass (BG C a) with a reduced tendency to crystallize compared to the widely used 45S5 Bioglass®. The rich glassy phase, which can be preserved during the thermal treatment, has excellent effects in terms of in vitro bioactivity; moreover, compared to composites based on 45S5 Bioglass® having the same HA/glass proportions, the samples based on BG C a displayed an earlier response in terms of cell proliferation. - Highlights: ► New apatite/bioglass composites are proposed and sintered at low temperature. ► The samples' glassy phase is preserved and the apatite decomposition is avoided. ► The rich glassy phase in the samples results in an excellent bioactivity. ► The samples are able to support cell adhesion and proliferation. ► The samples support faster cell proliferation compared to 45S5Bioglass-composites

  8. The comparison study of bioactivity between composites containing synthetic non-substituted and carbonate-substituted hydroxyapatite

    International Nuclear Information System (INIS)

    Borkowski, Leszek; Sroka-Bartnicka, Anna; Drączkowski, Piotr; Ptak, Agnieszka; Zięba, Emil; Ślósarczyk, Anna; Ginalska, Grażyna

    2016-01-01

    Apatite forming ability of hydroxyapatite (HAP) and carbonate hydroxyapatite (CHAP) containing composites was compared. Two composite materials, intended for filling bone defects, were made of polysaccharide polymer and one of two types of hydroxyapatite. The bioactivity of the composites was evaluated in vitro by soaking in a simulated body fluid (SBF), and the formation of the apatite layer was determined by scanning electron microscopy with energy-dispersive spectrometer and Raman spectroscopy. The results showed that both the composites induced the formation of apatite layer on their surface after soaking in SBF. In addition, the sample weight changes and the ion concentration of the SBF were scrutinized. The results showed the weight increase for both materials after SBF treatment, higher weight gain and higher uptake of calcium ions by HAP containing scaffolds. SBF solution analysis indicated loss of calcium and phosphorus ions during experiment. All these results indicate apatite forming ability of both biomaterials and suggest comparable bioactive properties of composite containing pure hydroxyapatite and carbonate-substituted one. - Highlights: • Bioactivity of two calcium phosphates (HAP and CHAP) was compared. • Two novel ceramic-polymer composite materials were developed. • We examined apatite forming ability of scaffolds in SBF solution. • We report comparable bioactive properties between both materials.

  9. The comparison study of bioactivity between composites containing synthetic non-substituted and carbonate-substituted hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Borkowski, Leszek, E-mail: leszek.borkowski@umlub.pl [Chair and Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodźki 1, 20-093 Lublin (Poland); Sroka-Bartnicka, Anna [Department of Biopharmacy, Medical University of Lublin, Chodźki 4a, 20-093 Lublin (Poland); Drączkowski, Piotr [Department of Synthesis and Chemical Technology of Pharmaceutical Substances, Medical University of Lublin, Chodźki 4a, 20-093 Lublin (Poland); Ptak, Agnieszka [Chair and Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodźki 1, 20-093 Lublin (Poland); Zięba, Emil [SEM Laboratory, Department of Zoology and Ecology, John Paul II Catholic University of Lublin, Al. Kraśnicka 102, 20-718 Lublin (Poland); Ślósarczyk, Anna [Faculty of Materials Science and Ceramics, AGH-University of Science and Technology, Mickiewicza 30, 30-059 Krakow (Poland); Ginalska, Grażyna [Chair and Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodźki 1, 20-093 Lublin (Poland)

    2016-05-01

    Apatite forming ability of hydroxyapatite (HAP) and carbonate hydroxyapatite (CHAP) containing composites was compared. Two composite materials, intended for filling bone defects, were made of polysaccharide polymer and one of two types of hydroxyapatite. The bioactivity of the composites was evaluated in vitro by soaking in a simulated body fluid (SBF), and the formation of the apatite layer was determined by scanning electron microscopy with energy-dispersive spectrometer and Raman spectroscopy. The results showed that both the composites induced the formation of apatite layer on their surface after soaking in SBF. In addition, the sample weight changes and the ion concentration of the SBF were scrutinized. The results showed the weight increase for both materials after SBF treatment, higher weight gain and higher uptake of calcium ions by HAP containing scaffolds. SBF solution analysis indicated loss of calcium and phosphorus ions during experiment. All these results indicate apatite forming ability of both biomaterials and suggest comparable bioactive properties of composite containing pure hydroxyapatite and carbonate-substituted one. - Highlights: • Bioactivity of two calcium phosphates (HAP and CHAP) was compared. • Two novel ceramic-polymer composite materials were developed. • We examined apatite forming ability of scaffolds in SBF solution. • We report comparable bioactive properties between both materials.

  10. Bioactive hydroxyapatite/graphene composite coating and its corrosion stability in simulated body fluid

    Energy Technology Data Exchange (ETDEWEB)

    Janković, Ana; Eraković, Sanja [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11 000 Belgrade (Serbia); Mitrić, Miodrag [Vinča Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11 000 Belgrade (Serbia); Matić, Ivana Z.; Juranić, Zorica D. [Institute of Oncology and Radiology of Serbia, Pasterova 14, 11 000 Belgrade (Serbia); Tsui, Gary C.P.; Tang, Chak-yin [Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Mišković-Stanković, Vesna [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11 000 Belgrade (Serbia); Rhee, Kyong Yop, E-mail: rheeky@khu.ac.kr [Department of Mechanical Engineering, Kyung Hee University, Yongin 449-701 (Korea, Republic of); Park, Soo Jin [Chemistry, College of Natural Sciences, Inha University, Incheon 402-751 (Korea, Republic of)

    2015-03-05

    Highlights: • Bioactive HAP/Gr coating on Ti was successfully obtained by EPD. • Increased fracture toughness of the HAP/Gr coating compared to pure HAP coating. • HAP/Gr coating exhibited superior biomimetic mineralization vs. pure HAP coating. • Gr improved the mechanical properties and thermal stability of HAP/Gr coating. • HAP/Gr coating was classified as non-cytotoxic against the targeted PBMC. - Abstract: The hydroxyapatite/graphene (HAP/Gr) composite was electrodeposited on Ti using the electrophoretic deposition process to obtain uniform bioactive coating with improved mechanical strength and favorable corrosion stability in simulated body fluid (SBF). Incorporation of Gr was verified by Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron analysis. The HAP/Gr composite coating exhibited reduced surface cracks, nearly double the hardness, and elastic modulus increased by almost 50% compared to pure HAP coating, as estimated by a nanoindentation test. The bioactive HAP/Gr composite coating provided a newly formed apatite layer in SBF with enhanced corrosion stability, as evidenced by electrochemical impedance spectroscopy. The thermal stability of the HAP/Gr coating was improved in comparison to the pure HAP coating, and the Ca/P ratio was closer to the stoichiometric value. No antibacterial activity against Staphylococcus aureus or Escherichia coli could be verified. The HAP/Gr composite coating was classified as non-cytotoxic when tested against healthy peripheral blood mononuclear cells (PBMC)

  11. Bioactivity and structural properties of nanostructured bulk composites containing Nb2O5 and natural hydroxyapatite

    Science.gov (United States)

    Bonadio, T. G. M.; Sato, F.; Medina, A. N.; Weinand, W. R.; Baesso, M. L.; Lima, W. M.

    2013-06-01

    In this work, we investigate the bioactivity and structural properties of nanostructured bulk composites that are composed of Nb2O5 and natural hydroxyapatite (HAp) and are produced by mechanical alloying and powder metallurgy. X-ray diffraction and Raman spectroscopy data showed that the milling process followed by a heat treatment at 1000 °C induced chemical reactions along with the formation of the CaNb2O6, PNb9O25 and Ca3(PO4)2 phases. Rietveld refinement indicated significant changes in each phase weight fraction as a function of HAp concentration. These changes influenced the in vitro bioactivity of the material. XRD and FTIR analyses indicated that the composites exhibited bioactivity characteristics by forming a carbonated apatite layer when the composites were immersed in a simulated body fluid. The formed layers had a maximum thickness of 13 μm, as measured by confocal Raman spectroscopy and as confirmed by scanning electron microscopy. The results of this work suggest that the tested bulk composites are promising biomaterials for use in implants.

  12. Bioactive hydroxyapatite/graphene composite coating and its corrosion stability in simulated body fluid

    International Nuclear Information System (INIS)

    Janković, Ana; Eraković, Sanja; Mitrić, Miodrag; Matić, Ivana Z.; Juranić, Zorica D.; Tsui, Gary C.P.; Tang, Chak-yin; Mišković-Stanković, Vesna; Rhee, Kyong Yop; Park, Soo Jin

    2015-01-01

    Highlights: • Bioactive HAP/Gr coating on Ti was successfully obtained by EPD. • Increased fracture toughness of the HAP/Gr coating compared to pure HAP coating. • HAP/Gr coating exhibited superior biomimetic mineralization vs. pure HAP coating. • Gr improved the mechanical properties and thermal stability of HAP/Gr coating. • HAP/Gr coating was classified as non-cytotoxic against the targeted PBMC. - Abstract: The hydroxyapatite/graphene (HAP/Gr) composite was electrodeposited on Ti using the electrophoretic deposition process to obtain uniform bioactive coating with improved mechanical strength and favorable corrosion stability in simulated body fluid (SBF). Incorporation of Gr was verified by Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron analysis. The HAP/Gr composite coating exhibited reduced surface cracks, nearly double the hardness, and elastic modulus increased by almost 50% compared to pure HAP coating, as estimated by a nanoindentation test. The bioactive HAP/Gr composite coating provided a newly formed apatite layer in SBF with enhanced corrosion stability, as evidenced by electrochemical impedance spectroscopy. The thermal stability of the HAP/Gr coating was improved in comparison to the pure HAP coating, and the Ca/P ratio was closer to the stoichiometric value. No antibacterial activity against Staphylococcus aureus or Escherichia coli could be verified. The HAP/Gr composite coating was classified as non-cytotoxic when tested against healthy peripheral blood mononuclear cells (PBMC)

  13. Laser surface modification of 316 L stainless steel with bioactive hydroxyapatite.

    Science.gov (United States)

    Balla, Vamsi Krishna; Das, Mitun; Bose, Sreyashree; Ram, G D Janaki; Manna, Indranil

    2013-12-01

    Laser-engineered net shaping (LENS™), a commercial additive manufacturing process, was used to modify the surfaces of 316 L stainless steel with bioactive hydroxyapatite (HAP). The modified surfaces were characterized in terms of their microstructure, hardness and apatite forming ability. The results showed that with increase in laser energy input from 32 J/mm(2) to 59 J/mm(2) the thickness of the modified surface increased from 222±12 μm to 355±6 μm, while the average surface hardness decreased marginally from 403±18 HV0.3 to 372±8 HV0.3. Microstructural studies showed that the modified surface consisted of austenite dendrites with HAP and some reaction products primarily occurring in the inter-dendritic regions. Finally, the surface-modified 316 L samples immersed in simulated body fluids showed significantly higher apatite precipitation compared to unmodified 316 L samples. © 2013.

  14. Adsorption and Desorption of Bioactive Proteins on Hydroxyapatite for Protein Delivery Systems

    Directory of Open Access Journals (Sweden)

    Chie Kojima

    2012-01-01

    Full Text Available Hydroxyapatite (HA is a precursor of bone and has been studied as a biomaterial. We attempted HA to apply to protein delivery systems. In this study, the association and dissociation properties of two types of bioactive proteins, cytochrom c and insulin, to HA were investigated. Cytochrom c was less associated with HA than insulin, which was easily released from it. However, the release of insulin from HA was slow. Insulin was released from HA at pH 7.4 more rapidly than at pH 3. The association and dissociation properties might be influenced by the size, solubility and net charge of protein. HA is a potential protein carrier with controlled release.

  15. Hydroxyapatite additive influenced the bioactivity of bioactive nano-titania ceramics and new bone-forming capacity

    Energy Technology Data Exchange (ETDEWEB)

    Li Zhensheng [Third Military Medical University, College of Biomedical Engineering and Medical Imaging (China); Yang Xiaozhan [Chongqing University of Technology, School of Optoelectronic Information (China); Guo Hongfeng [Third Military Medical University, Tissue Engineering Research Center of Chongqing, Department of Anatomy, College of Basic Medical Sciences (China); Yang Xiaochao; Sun Lili [Third Military Medical University, College of Biomedical Engineering and Medical Imaging (China); Dong Shiwu, E-mail: shiwudong@gmail.com [Third Military Medical University, Tissue Engineering Research Center of Chongqing, Department of Anatomy, College of Basic Medical Sciences (China)

    2012-09-15

    Bioceramics plays an important role in bone-substitutes. In this study, titania porous ceramics with excellent bioactivity were prepared using hydroxyapatite (HA, 10 vol.% contents) as a grain growth inhibitor. The pure TiO{sub 2} porous ceramics were also prepared as a control. After sintered at 1,000 Degree-Sign C with a pressureless sintering method, the particle size of the pure TiO{sub 2} and TiO{sub 2}/HA (10 vol.%) porous ceramics were 450 and 310 nm, respectively. Each of the porous ceramics presented numerous pores, which were cross-connected. The size of the pores ranged from 100 to 300 {mu}m. There were also profuse micropores inside the pore wall and between the particles. A SBF soaking experiment demonstrated that the HA additive played an important role in promoting apatite formation. The cell proliferation demonstrated that osteoblasts on the TiO{sub 2}/HA (10 vol.%) porous ceramics proliferated faster than that on the pure TiO{sub 2} ceramics. The histological sections and EDX assay results of the two porous ceramics also illustrated that TiO{sub 2}/HA (10 vol.%) composite ceramics combined with Ca and P elements induced much better apatite formation than that of the pure TiO{sub 2} ceramics. These results indicated that titania ceramics combined with HA holds great promise for bone-substitutes.

  16. Preparation and bioactivity evaluation of hydroxyapatite-titania/chitosan-gelatin polymeric biocomposites

    International Nuclear Information System (INIS)

    Mohamed, Khaled R.; Mostafa, Amani A.

    2008-01-01

    Biocomposites consisting of hydroxyapatite (HA) and natural polymers such as collagen, chitosan, chitin,and gelatin have been extensively investigated. However, studies on the combination of HA and titania with chitosan and gelatin have not been conducted yet. Novel biodegradable hydroxyapatite-titania/chitosan-gelatin polymeric composites were fabricated. In this work, our results are concerning with the preparation and characterization of HA powder and HA filler containing titania powder (10 and 30%) with a chitosan and gelatin copolymer matrix. The present research focuses on characterizing the structure of this novel class of biocomposites. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning electron microscopy (SEM-EDAX) were employed to assess the produced composites. The mechanical properties in terms of compressive strength and hardness test were also investigated. The in vitro study in simulated body fluid (SBF) was performed to assess the bioactivity of composites. The results proved that apatite resembling natural bone are formed faster and greater in the case the composite of HA containing 10% titania into chitosan-gelatin polymeric matrix when they are soaked in a simulated body fluid (SBF) than the composite containing 30% titania. The biocomposites containing HA with 10% titania are expected to be attractive for bioapplications as bone substitutes and scaffolds for tissue engineering in future

  17. Effect of silicon, tantalum, and tungsten doping and polarization on bioactivity of hydroxyapatite

    Science.gov (United States)

    Dhal, Jharana

    Hydroxyapatite (HAp) ceramics has important applications as bone graft because of the structural and compositional similarities with bone tissue. However, inferior osteogenic capacity to bone and poor mechanical properties have been identified to be major disadvantages of synthetic HAp compared to the living bone tissue. The objective of the current study is to evaluate the effect of doping with higher valent cations (Tungsten, tantalum, and silicon) and polarization or combination of both on change in property of doped HAp and subsequent impact its bioactivity. In vitro study with human osteoblast cells was used to investigate the influences of doping and polarization on bone cell-materials interactions. The bioactivity of doped HAp was compared with pure HAp. Effect of doping and polarization on the change in HAp was investigated by monitoring change in mineral phases, stored charge, and activation energy of HAp. Activation energy of depolarization was used to explain the possible mechanism of polarization in doped samples. Bioactivity of HAp increased when doped with tantalum and tungsten. Polarization further increased the bioactivity of tungsten- and tantalum-doped samples. Increase in bioactivity on polarized and doped samples was attributed to increase in surface energy and increase in surface wettability. Whereas, an increase in bioactivity on doped unpolarized surface was attributed to change in microstructure. Polarized charge calculated from TSDC indicates that polarized charge decreases on tantalum- and tungsten-doped HAp. The decrease in polarized charge was attributed to the presence of significant amount of different phases that may hinder the ionic motion in doped samples. However, for silicon-doped HAp, TSDC study showed no difference in the mechanism of polarization between doped and undoped samples. Increase in silicon doping decreased the grain size though mechanism is not affected by grain size. Total stored charge decreased with increase in

  18. XPS and bioactivity study of the bisphosphonate pamidronate adsorbed onto plasma sprayed hydroxyapatite coatings

    International Nuclear Information System (INIS)

    McLeod, Kate; Kumar, Sunil; Smart, Roger St.C.; Dutta, Naba; Voelcker, Nicolas H.; Anderson, Gail I.; Sekel, Ron

    2006-01-01

    This paper reports the use of X-ray photoelectron spectroscopy (XPS) to investigate bisphosphonate (BP) adsorption onto plasma sprayed hydroxyapatite (HA) coatings commonly used for orthopaedic implants. BPs exhibit high binding affinity for the calcium present in HA and hence can be adsorbed onto HA-coated implants to exploit their beneficial properties for improved bone growth at the implant interface. A rigorous XPS analysis of pamidronate, a commonly used nitrogenous BP, adsorbed onto plasma sprayed HA-coated cobalt-chromium substrates has been carried out, aimed at: (a) confirming the adsorption of this BP onto HA; (b) studying the BP diffusion profile in the HA coating by employing the technique of XPS depth profiling; (c) confirming the bioactivity of the adsorbed BP. XPS spectra of plasma sprayed HA-coated discs exposed to a 10 mM aqueous BP solution (pamidronate) for periods of 1, 2 and 24 h showed nitrogen and phosphorous photoelectron signals corresponding to the BP, confirming its adsorption onto the HA substrate. XPS depth profiling of the 2 h BP-exposed HA discs showed penetration of the BP into the HA matrix to depths of at least 260 nm. The bioactivity of the adsorbed BP was confirmed by the observed inhibition of osteoclast (bone resorbing) cell activity. In comparison to the HA sample, the HA sample with adsorbed BP exhibited a 25-fold decrease in primary osteoclast cells

  19. Enhanced bioactivity and biocompatibility of nanostructured hydroxyapatite coating by hydrothermal annealing

    International Nuclear Information System (INIS)

    Hahn, Byung-Dong; Lee, Jeong-Min; Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Lee, Byoung-Kuk; Kim, Jong-Woo; Kim, Hyoun-Ee; Kim, Seong-Gon

    2011-01-01

    The crystallinity of hydroxyapatite (HA) coatings prepared by aerosol deposition may be increased by heating in air or low-temperature hydrothermal processing. From the X-ray diffraction and Fourier transform infrared spectroscopy results, it was revealed that the crystallinity of the HA coatings significantly increased after the post-annealing. Transmission electron microscopy showed that the conventional furnace heating induced the substantial growth of the HA crystallites, whereas the hydrothermal treatment did not bring about any remarkable change in the HA crystallite size, which remained below 20 nm. The bioactivity of the HA coatings was estimated by the acellular simulated body fluid immersion test. After immersion for 7 days, newly-precipitated apatite crystals were only observed on the surfaces of the samples hydrothermally treated at 170 and 190 deg. C. In addition, the alkaline phosphatase activity of MC3T3-E1 preosteoblast cells cultured on the hydrothermally treated samples was significantly higher than those on the as-deposited coating and conventional furnace heated samples. The enhanced bioactivity and excellent biological in vitro cellular response of the hydrothermally treated samples were attributed to their nanostructured nature and high degree of crystallinity.

  20. The comparison study of bioactivity between composites containing synthetic non-substituted and carbonate-substituted hydroxyapatite.

    Science.gov (United States)

    Borkowski, Leszek; Sroka-Bartnicka, Anna; Drączkowski, Piotr; Ptak, Agnieszka; Zięba, Emil; Ślósarczyk, Anna; Ginalska, Grażyna

    2016-05-01

    Apatite forming ability of hydroxyapatite (HAP) and carbonate hydroxyapatite (CHAP) containing composites was compared. Two composite materials, intended for filling bone defects, were made of polysaccharide polymer and one of two types of hydroxyapatite. The bioactivity of the composites was evaluated in vitro by soaking in a simulated body fluid (SBF), and the formation of the apatite layer was determined by scanning electron microscopy with energy-dispersive spectrometer and Raman spectroscopy. The results showed that both the composites induced the formation of apatite layer on their surface after soaking in SBF. In addition, the sample weight changes and the ion concentration of the SBF were scrutinized. The results showed the weight increase for both materials after SBF treatment, higher weight gain and higher uptake of calcium ions by HAP containing scaffolds. SBF solution analysis indicated loss of calcium and phosphorus ions during experiment. All these results indicate apatite forming ability of both biomaterials and suggest comparable bioactive properties of composite containing pure hydroxyapatite and carbonate-substituted one. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Electrospun polyurethane/hydroxyapatite bioactive scaffolds for bone tissue engineering: the role of solvent and hydroxyapatite particles.

    Science.gov (United States)

    Tetteh, G; Khan, A S; Delaine-Smith, R M; Reilly, G C; Rehman, I U

    2014-11-01

    Polyurethane (PU) is a promising polymer to support bone-matrix producing cells due to its durability and mechanical resistance. In this study two types of medical grade poly-ether urethanes Z3A1 and Z9A1 and PU-Hydroxyapatite (PU-HA) composites were investigated for their ability to act as a scaffold for tissue engineered bone. PU dissolved in varying concentrations of dimethylformamide (DMF) and tetrahydrofuran (THF) solvents were electrospun to attain scaffolds with randomly orientated non-woven fibres. Bioactive polymeric composite scaffolds were created using 15 wt% Z3A1 in a 70/30 DMF/THF PU solution and incorporating micro- or nano-sized HA particles in a ratio of 3:1 respectively, whilst a 25 wt% Z9A1 PU solution was doped in ratio of 5:1. Chemical properties of the resulting composites were evaluated by FTIR and physical properties by SEM. Tensile mechanical testing was carried out on all electrospun scaffolds. MLO-A5 osteoblastic mouse cells and human embryonic mesenchymal progenitor cells, hES-MPs were seeded on the scaffolds to test their biocompatibility and ability to support mineralised matrix production over a 28 day culture period. Cell viability was assayed by MTT and calcium and collagen deposition by Sirius red and alizarin red respectively. SEM images of both electrospun PU scaffolds and PU-HA composite scaffolds showed differences in fibre morphology with changes in solvent combinations and size of HA particles. Inclusion of THF eliminated the presence of beads in fibres that were present in scaffolds fabricated with 100% DMF solvent, and resulted in fibres with a more uniform morphology and thicker diameters. Mechanical testing demonstrated that the Young׳s Modulus and yield strength was lower at higher THF concentrations. Inclusion of both sizes of HA particles in PU-HA solutions reinforced the scaffolds leading to higher mechanical properties, whilst FTIR characterisation confirmed the presence of HA in all composite scaffolds. Although

  2. Structural characterization, optical properties and in vitro bioactivity of mesoporous erbium-doped hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Alshemary, Ammar Z.; Akram, Muhammed; Goh, Yi-Fan [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Darul Ta’zim (Malaysia); Abdul Kadir, Mohammed Rafiq [Medical Implant Technology Group, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Darul Ta’zim (Malaysia); Abdolahi, Ahmad [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Darul Ta’zim (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@kimia.fs.utm.my [Centre for Sustainable Nanomaterials (CSNano), Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Darul Ta’zim (Malaysia)

    2015-10-05

    Highlights: • Phase pure nano-sized Er doped hydroxyapatite has been prepared. • TEM micrograph confirmed formation of mesoporous material. • Increased Er doping resulted in blue shift with slight increase in energy band gab. • Er-HA showed better dissolution behavior in SBF comparing with pure HA. • Er doping of HA resulted in formation of apatite layer in SBF with Ca/P ratio of 1.72. - Abstract: We report the successful synthesis of mesoporous erbium doped hydroxyapatite (Er-HA, Ca{sub 10−x}Er{sub 2x/3}□{sub x/3}(PO{sub 4}){sub 6}(OH){sub 2}) by using a rapid and efficient microwave assisted wet precipitation method. Characterization techniques like X-ray diffraction (XRD), Fourier transform infra-red (FTIR), X-ray fluorescence spectrometer (XRF), Brunauer, Emmett and Teller (BET) and transmission electron microscopy (TEM) were used to determine lattice parameters, particle size, degree of crystallinity, elemental composition, surface area and morphology of Er-HA. Results confirmed the formation of crystalline Er-HA having crystallite size of 25 nm with spherical and rod like morphology, while the TEM analysis confirmed the mesoporous nature of the particles. Optical spectra of Er-HA contained seven electron transitions, whereas blue shift in the energy band gap (E{sub g}) was observed upon increase in Er{sup 3+} content. The photoluminescence (PL) spectra contained green and red emissions. In vitro bioactivity study conducted in SBF revealed that the incorporation of Er{sup 3+} ions into HA structure lead to the faster discharge of Er{sup 3+} ions resulting in intense growth of apatite grains on the surface of the Er-HA pellets with Ca/P ratio of 1.72.

  3. Cellulose acetate/hydroxyapatite/chitosan coatings for improved corrosion resistance and bioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Zhenyu; Qin, Jinli [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Ma, Jun, E-mail: caltary@gmail.com [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-04-01

    Cellulose acetate (CA) nanofibers were deposited on stainless steel plates by electrospinning technique. The composite of hydroxyapatite (HAP) nanoparticles and chitosan (CHI) was coated subsequently by dip-coating. The structure and morphology of the obtained coatings were investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. The stability of the coatings in physiological environment was studied using electrochemical polarization and impedance spectroscopy. The CA nanofibers were embedded in the HAP/CHI coating and the resulted composite film was densely packed and uniform on the substrate. The in vitro biomineralization study of the coated samples immersed in simulated body fluid (SBF) confirmed the formation ability of bone-like apatite layer on the surface of HAP-containing coatings. Furthermore, the coatings could provide corrosion resistance to the stainless steel substrate in SBF. The electrochemical results suggested that the incorporation of CA nanofibers could improve the corrosion resistance of the HAP/CHI coating. Thus, biocompatible CA/HAP/CHI coated metallic implants could be very useful in the long-term stability of the biomedical applications. - Highlights: • The composite coatings were prepared by electrospinning and dip-coating. • Good in vitro bioactivity of the CA/HAP/CHI coating was confirmed. • Electrochemical behaviors in SBF of the coatings have been studied. • The CA/HAP/CHI coating shows better resistance property than HAP/CHI.

  4. Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gyorgy, E. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania) and Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Barcelona, Campus UAB, 08193 Bellaterra (Spain)]. E-mail: egyorgy@icmab.es; Grigorescu, S. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania); Socol, G. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania); Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania); Janackovic, D. [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia); Dindune, A. [Institute of Inorganic Chemistry of the Riga Technical University (Latvia); Plasma and Ceramic Technologies Ltd. (PCT Ltd.) (Latvia); Kanepe, Z. [Institute of Inorganic Chemistry of the Riga Technical University (Latvia); Plasma and Ceramic Technologies Ltd. (PCT Ltd.) (Latvia); Palcevskis, E. [Plasma and Ceramic Technologies Ltd. (PCT Ltd.) (Latvia); Zdrentu, E.L. [Institute of Biochemistry, Splaiul Independentei 296, Bucharest (Romania); Petrescu, S.M. [Institute of Biochemistry, Splaiul Independentei 296, Bucharest (Romania)

    2007-07-31

    Bioactive glass (BG), calcium hydroxyapatite (HA), and ZrO{sub 2} doped HA thin films were grown by pulsed laser deposition on Ti substrates. An UV KrF{sup *} ({lambda} = 248 nm, {tau} {>=} 7 ns) excimer laser was used for the multi-pulse irradiation of the targets. The substrates were kept at room temperature or heated during the film deposition at values within the (400-550 deg. C) range. The depositions were performed in oxygen and water vapor atmospheres, at pressure values in the range (5-40 Pa). The HA coatings were heat post-treated for 6 h in a flux of hot water vapors at the same temperature as applied during deposition. The surface morphology, chemical composition, and crystalline quality of the obtained thin films were studied by scanning electron microscopy, atomic force microscopy, and X-ray diffractometry. The films were seeded for in vitro tests with Hek293 (human embryonic kidney) cells that revealed a good adherence on the deposited layers. Biocompatibility tests showed that cell growth was better on HA than on BG thin films.

  5. Synthesis, cytotoxicity, and hydroxyapatite formation in 27-Tris-SBF for sol-gel based CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses.

    Science.gov (United States)

    Kaur, Gurbinder; Pickrell, G; Kimsawatde, G; Homa, D; Allbee, H A; Sriranganathan, N

    2014-03-18

    CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses were prepared via an optimized sol-gel method. The current investigation was focused on producing novel zinc based calcium phosphoborosilicate glasses and to evaluate their mechanical, rheological, and biocompatible properties. The morphology and composition of these glasses were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The particle size, mechanical and flexural strength was also determined. Furthermore, the zeta potential of all the glasses were determined to estimate their flocculation tendency. The thermal analysis and weight loss measurements were carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon their immersion in simulated body fluid (SBF) was checked using SEM and pH measurements. MTS assay cytotoxicity assay and live-dead cell viability test were conducted on J774A.1 cells murine macrophage cells for different glass concentrations.

  6. Hydroxyapatite-diamondlike carbon nanocomposite films

    International Nuclear Information System (INIS)

    Narayan, Roger J.

    2005-01-01

    Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Conventional plasma-sprayed hydroxyapatite coatings demonstrate poor adhesion and poor mechanical integrity. We have developed hydroxyapatite-diamondlike carbon bilayer film. The diamondlike carbon interlayer serves to prevent metal ion release and improve adhesion of the hydroxyapatite film. These films were characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, nanoindentation, and microscratch adhesion testing. Based on the results of this study, hydroxyapatite-diamondlike carbon bilayers demonstrate promise for use in several orthopedic implants

  7. Hydroxyapatite-diamondlike carbon nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Roger J. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)]. E-mail: roger.narayan@mse.gatech.edu

    2005-05-15

    Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Conventional plasma-sprayed hydroxyapatite coatings demonstrate poor adhesion and poor mechanical integrity. We have developed hydroxyapatite-diamondlike carbon bilayer film. The diamondlike carbon interlayer serves to prevent metal ion release and improve adhesion of the hydroxyapatite film. These films were characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, nanoindentation, and microscratch adhesion testing. Based on the results of this study, hydroxyapatite-diamondlike carbon bilayers demonstrate promise for use in several orthopedic implants.

  8. Hydroxyapatite nanocrystals functionalized with alendronate as bioactive components for bone implant coatings to decrease osteoclastic activity

    Science.gov (United States)

    Bosco, Ruggero; Iafisco, Michele; Tampieri, Anna; Jansen, John A.; Leeuwenburgh, Sander C. G.; van den Beucken, Jeroen J. J. P.

    2015-02-01

    The integration of bone implants within native bone tissue depends on periprosthetic bone quality, which is severely decreased in osteoporotic patients. In this work, we have synthesized bone-like hydroxyapatite nanocrystals (nHA) using an acid-base neutralization reaction and analysed their physicochemical properties. Subsequently, we have functionalized the nHA with alendronate (nHAALE), a well-known bisphosphonate drug used for the treatment of osteoporosis. An in vitro osteoclastogenesis test was carried out to evaluate the effect of nHAALE on the formation of osteoclast-like cells from monocytic precursor cells (i.e. RAW264.7 cell line) showing that nHAALE significantly promoted apoptosis of osteoclast-like cells. Subsequently, nHA and nHAALE were deposited on titanium disks using electrospray deposition (ESD), for which characterisation of the deposited coatings confirmed the presence of alendronate in nHAALE coatings with nanoscale thickness of about 700 nm. These results indicate that alendronate linked to hydroxyapatite nanocrystals has therapeutic potential and nHAALE can be considered as an appealing coating constituent material for orthopaedic and oral implants for application in osteoporotic patients.

  9. Microstructures, hardness and bioactivity of hydroxyapatite coatings deposited by direct laser melting process

    International Nuclear Information System (INIS)

    Tlotleng, Monnamme; Akinlabi, Esther; Shukla, Mukul; Pityana, Sisa

    2014-01-01

    Hydroxyapatite (HAP) coatings on bioinert metals such as Ti–6Al–4V are necessary for biomedical applications. Together, HAP and Ti–6Al–4V are biocompatible and bioactive. The challenges of depositing HAP on Ti–6Al–4V with traditional thermal spraying techniques are well founded. In this paper, HAP was coated on Ti–6Al–4V using direct laser melting (DLM) process. This process, unlike the traditional coating processes, is able to achieve coatings with good metallurgical bonding and little dilution. The microstructural and mechanical properties, chemical composition and bio-activities of the produced coatings were studied with optical microscopy, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and Vickers hardness machine, and by immersion test in Hanks' solution. The results showed that the choice of the laser power has much influence on the evolving microstructure, the mechanical properties and the retainment of HAP on the surface of the coating. Also, the choice of laser power of 750 W led to no dilution. The microhardness results inferred a strong intermetallic–ceramic interfacial bonding; which meant that the 750 W coating could survive long in service. Also, the coating was softer at the surface and stronger in the heat affected zones. Hence, this process parameter setting can be considered as an optimal setting. The soak tests revealed that the surface of the coating had unmelted crystals of HAP. The CaP ratio conducted on the soaked coating was 2.00 which corresponded to tetra calcium phosphate. This coating seems attractive for metallic implant applications. - Highlights: • Characteristics of HAP coatings produced on Ti-6Al-4V achieved with direct laser melting are reported. • Optimal process parameters necessary to achieve biocompatible coating are reported. • The SEM micrograph of the soaked HAP coating revealed partially melted crystals of HAP. • The HAP coating was retained at the surface of

  10. Microstructures, hardness and bioactivity of hydroxyapatite coatings deposited by direct laser melting process

    Energy Technology Data Exchange (ETDEWEB)

    Tlotleng, Monnamme, E-mail: MTlotleng@csir.co.za [Laser Materials Processing Group, National Laser Center CSIR, Pretoria 0001 (South Africa); Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park, Kingsway Campus, Johannesburg 2006 (South Africa); Akinlabi, Esther [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park, Kingsway Campus, Johannesburg 2006 (South Africa); Shukla, Mukul [Department of Mechanical Engineering Technology, University of Johannesburg, Doornfontein Campus, Johannesburg 2006 (South Africa); Department of Mechanical Engineering, MNNIT, Allahabad, UP 211004 (India); Pityana, Sisa [Laser Materials Processing Group, National Laser Center CSIR, Pretoria 0001 (South Africa); Department of Chemical and Metallurgical Engineering, Tshwane University of Technology, Pretoria 0001 (South Africa)

    2014-10-01

    Hydroxyapatite (HAP) coatings on bioinert metals such as Ti–6Al–4V are necessary for biomedical applications. Together, HAP and Ti–6Al–4V are biocompatible and bioactive. The challenges of depositing HAP on Ti–6Al–4V with traditional thermal spraying techniques are well founded. In this paper, HAP was coated on Ti–6Al–4V using direct laser melting (DLM) process. This process, unlike the traditional coating processes, is able to achieve coatings with good metallurgical bonding and little dilution. The microstructural and mechanical properties, chemical composition and bio-activities of the produced coatings were studied with optical microscopy, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and Vickers hardness machine, and by immersion test in Hanks' solution. The results showed that the choice of the laser power has much influence on the evolving microstructure, the mechanical properties and the retainment of HAP on the surface of the coating. Also, the choice of laser power of 750 W led to no dilution. The microhardness results inferred a strong intermetallic–ceramic interfacial bonding; which meant that the 750 W coating could survive long in service. Also, the coating was softer at the surface and stronger in the heat affected zones. Hence, this process parameter setting can be considered as an optimal setting. The soak tests revealed that the surface of the coating had unmelted crystals of HAP. The CaP ratio conducted on the soaked coating was 2.00 which corresponded to tetra calcium phosphate. This coating seems attractive for metallic implant applications. - Highlights: • Characteristics of HAP coatings produced on Ti-6Al-4V achieved with direct laser melting are reported. • Optimal process parameters necessary to achieve biocompatible coating are reported. • The SEM micrograph of the soaked HAP coating revealed partially melted crystals of HAP. • The HAP coating was retained at the surface of

  11. Characterization of fabricated cobalt-based alloy/nano bioactive glass composites

    Energy Technology Data Exchange (ETDEWEB)

    Bafandeh, Mohammad Reza, E-mail: mr.bafandeh@gmail.com [Department of Materials Science and Engineering, Faculty of Engineering, University of Kashan, Kashan (Iran, Islamic Republic of); Gharahkhani, Raziyeh; Fathi, Mohammad Hossein [Department of Materials Engineering, Isfahan University of Technology (IUT), Isfahan 84156-83111 (Iran, Islamic Republic of)

    2016-12-01

    In this work, cobalt-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared and their bioactivity after immersion in simulated body fluid (SBF) for 1 to 4 weeks was studied. Scanning electron microscopy images of two- step sintered composites revealed relatively dense microstructure. The results showed that density of composite samples decreased with increase in NBG amount. The microstructure analysis as well as energy dispersive X-ray analysis (EDX) revealed that small amount of calcium phosphate phases precipitates on the surface of composite samples after 1 week immersion in SBF. After 2 weeks immersion, considerable amounts of cauliflower-like shaped precipitations were seen on the surface of the composites. Based on EDX analysis, these precipitations were composed mainly from Ca, P and Si. The observed bands in the Fourier transform infrared spectroscopy of immersed composites samples for 4 weeks in SBF, were characteristic bands of hydroxyapatite. Therefore it is possible to form hydroxyapatite layer on the surface of composite samples during immersion in SBF. The results indicated that prepared composites unlike cobalt-based alloy are bioactive, promising their possibility for implant applications. - Highlights: • Co-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared. • In order to study their bioactivity, composite samples were immersed in SBF solution for 1 to 4 weeks. • Immersion in SBF accompanied with precipitation of hydroxyapatite on surface of samples. • Prepared composite samples unlike cobalt-based alloy were bioactive.

  12. Characterization of fabricated cobalt-based alloy/nano bioactive glass composites

    International Nuclear Information System (INIS)

    Bafandeh, Mohammad Reza; Gharahkhani, Raziyeh; Fathi, Mohammad Hossein

    2016-01-01

    In this work, cobalt-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared and their bioactivity after immersion in simulated body fluid (SBF) for 1 to 4 weeks was studied. Scanning electron microscopy images of two- step sintered composites revealed relatively dense microstructure. The results showed that density of composite samples decreased with increase in NBG amount. The microstructure analysis as well as energy dispersive X-ray analysis (EDX) revealed that small amount of calcium phosphate phases precipitates on the surface of composite samples after 1 week immersion in SBF. After 2 weeks immersion, considerable amounts of cauliflower-like shaped precipitations were seen on the surface of the composites. Based on EDX analysis, these precipitations were composed mainly from Ca, P and Si. The observed bands in the Fourier transform infrared spectroscopy of immersed composites samples for 4 weeks in SBF, were characteristic bands of hydroxyapatite. Therefore it is possible to form hydroxyapatite layer on the surface of composite samples during immersion in SBF. The results indicated that prepared composites unlike cobalt-based alloy are bioactive, promising their possibility for implant applications. - Highlights: • Co-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared. • In order to study their bioactivity, composite samples were immersed in SBF solution for 1 to 4 weeks. • Immersion in SBF accompanied with precipitation of hydroxyapatite on surface of samples. • Prepared composite samples unlike cobalt-based alloy were bioactive.

  13. Surface bioactivity modification of titanium by CO 2 plasma treatment and induction of hydroxyapatite: In vitro and in vivo studies

    Science.gov (United States)

    Hu, Xixue; Shen, Hong; Shuai, Kegang; Zhang, Enwei; Bai, Yanjie; Cheng, Yan; Xiong, Xiaoling; Wang, Shenguo; Fang, Jing; Wei, Shicheng

    2011-01-01

    Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.

  14. Facile fabrication of bioactive ultra-small protein–hydroxyapatite nanoconjugates via liquid-phase laser ablation and their enhanced osteogenic differentiation activity

    KAUST Repository

    Rodio, Marina; Coluccino, Luca; Romeo, Elisa; Genovese, Alessandro; Diaspro, Alberto; Garau, Gianpiero; Intartaglia, Romuald

    2016-01-01

    Hydroxyapatite bioactive complexes are being increasingly recognized as effective available means in regenerative medicine. Conventional technologies for their synthesis have drawbacks from a synthetic standpoint, mainly requiring high temperatures and multi-step processes. Here, we show that ultra-small hydroxyapatite conjugated-nanoparticles (Ha-CNPs) can be obtained at room temperature by Pulsed Laser Ablation (PLA) directly in protein solution using picosecond pulses at near infrared wavelengths. The results showed that the nanoparticle size was driven by the concentration of the protein. Using this approach, we obtained aqueous soluble and ultra-small crystalline nanoparticles of ≈3 nm diameter coated with protein molecules (surface coverage ≈ 5.5 pmol cm; zeta potential ≈-33.5 mV). These nanoparticles showed low cytotoxicity in vitro compared to chemically synthesized nanoparticles, and revealed proliferative and osteoinductive effects on human bone marrow mesenchymal stem cells (hMSCs). The resulting enhanced cell osteogenic differentiation suggested that our PLA-based synthetic approach might be exploited in novel applications of regenerative medicine.

  15. Facile fabrication of bioactive ultra-small protein–hydroxyapatite nanoconjugates via liquid-phase laser ablation and their enhanced osteogenic differentiation activity

    KAUST Repository

    Rodio, Marina

    2016-11-24

    Hydroxyapatite bioactive complexes are being increasingly recognized as effective available means in regenerative medicine. Conventional technologies for their synthesis have drawbacks from a synthetic standpoint, mainly requiring high temperatures and multi-step processes. Here, we show that ultra-small hydroxyapatite conjugated-nanoparticles (Ha-CNPs) can be obtained at room temperature by Pulsed Laser Ablation (PLA) directly in protein solution using picosecond pulses at near infrared wavelengths. The results showed that the nanoparticle size was driven by the concentration of the protein. Using this approach, we obtained aqueous soluble and ultra-small crystalline nanoparticles of ≈3 nm diameter coated with protein molecules (surface coverage ≈ 5.5 pmol cm; zeta potential ≈-33.5 mV). These nanoparticles showed low cytotoxicity in vitro compared to chemically synthesized nanoparticles, and revealed proliferative and osteoinductive effects on human bone marrow mesenchymal stem cells (hMSCs). The resulting enhanced cell osteogenic differentiation suggested that our PLA-based synthetic approach might be exploited in novel applications of regenerative medicine.

  16. Nanostructured hydroxyapatite surfaces-mediated adsorption alters recognition of BMP receptor IA and bioactivity of bone morphogenetic protein-2.

    Science.gov (United States)

    Huang, Baolin; Yuan, Yuan; Ding, Sai; Li, Jianbo; Ren, Jie; Feng, Bo; Li, Tong; Gu, Yuantong; Liu, Changsheng

    2015-11-01

    Highly efficient loading of bone morphogenetic protein-2 (BMP-2) onto carriers with desirable performance is still a major challenge in the field of bone regeneration. Till now, the nanoscaled surface-induced changes of the structure and bioactivity of BMP-2 remains poorly understood. Here, the effect of nanoscaled surface on the adsorption and bioactivity of BMP-2 was investigated with a series of hydroxyapatite surfaces (HAPs): HAP crystal-coated surface (HAP), HAP crystal-coated polished surface (HAP-Pol), and sintered HAP crystal-coated surface (HAP-Sin). The adsorption dynamics of recombinant human BMP-2 (rhBMP-2) and the accessibility of the binding epitopes of adsorbed rhBMP-2 for BMP receptors (BMPRs) were examined by a quartz crystal microbalance with dissipation. Moreover, the bioactivity of adsorbed rhBMP-2 and the BMP-induced Smad signaling were investigated with C2C12 model cells. A noticeably high mass-uptake of rhBMP-2 and enhanced recognition of BMPR-IA to adsorbed rhBMP-2 were found on the HAP-Pol surface. For the rhBMP-2-adsorbed HAPs, both ALP activity and Smad signaling increased in the order of HAP-Sinuses of rhBMP-2 in clinical applications and arouse broad interests among researchers in the fields of nano-biotechnology, biomaterials and bone tissue engineering. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Use of Raman microscopy and multivariate data analysis to observe the biomimetic growth of carbonated hydroxyapatite on bioactive glass.

    Science.gov (United States)

    Seah, Regina K H; Garland, Marc; Loo, Joachim S C; Widjaja, Effendi

    2009-02-15

    In the present contribution, the biomimetic growth of carbonated hydroxyapatite (HA) on bioactive glass were investigated by Raman microscopy. Bioactive glass samples were immersed in simulated body fluid (SBF) buffered solution at pH 7.40 up to 17 days at 37 degrees C. Raman microscopy mapping was performed on the bioglass samples immersed in SBF solution for different periods of time. The collected data was then analyzed using the band-target entropy minimization technique to extract the observable pure component Raman spectral information. In this study, the pure component Raman spectra of the precursor amorphous calcium phosphate, transient octacalcium phosphate, and matured HA were all recovered. In addition, pure component Raman spectra of calcite, silica glass, and some organic impurities were also recovered. The resolved pure component spectra were fit to the normalized measured Raman data to provide the spatial distribution of these species on the sample surfaces. The current results show that Raman microscopy and multivariate data analysis provide a sensitive and accurate tool to characterize the surface morphology, as well as to give more specific information on the chemical species present and the phase transformation of phosphate species during the formation of HA on bioactive glass.

  18. Bone regeneration based on nano-hydroxyapatite and hydroxyapatite/chitosan nanocomposites: an in vitro and in vivo comparative study

    International Nuclear Information System (INIS)

    Tavakol, S.; Nikpour, M. R.; Amani, A.; Soltani, M.; Rabiee, S. M.; Rezayat, S. M.; Chen, P.; Jahanshahi, M.

    2013-01-01

    Surface morphology, surface wettability, and size distribution of biomaterials affect their in vitro and in vivo bone regeneration potential. Since nano-hydroxyapatite has a great chemical and structural similarity to natural bone and dental tissues, incorporated biomaterial of such products could improve bioactivity and bone bonding ability. In this research, nano-hydroxyapatite (23 ± 0.09 nm) and its composites with variety of chitosan content [2, 4, and 6 g (45 ± 0.19, 32 ± 0.12, and 28 ± 0.12 nm, respectively)] were prepared via an in situ hybridization route. Size distribution of the particles, protein adsorption, and calcium deposition of powders by the osteoblast cells, gene expression and percentage of new bone formation area were investigated. The highest degree of bone regeneration potential was observed in nano-hydroxyapatite powder, while the bone regeneration was lowest in nano-hydroxyapatite with 6 g of chitosan. Regarding these data, suitable size distribution next to size distribution of hydroxyapatite in bone, smaller size, higher wettability, lower surface roughness of the nano-hydroxyapatite particles and homogeneity in surface resulted in higher protein adsorption, cell differentiation and percentage of bone formation area. Results obtained from in vivo and in vitro tests confirmed the role of surface morphology, surface wettability, mean size and size distribution of biomaterial besides surface chemistry as a temporary bone substitute.

  19. Sr-containing hydroxyapatite: morphologies of HA crystals and bioactivity on osteoblast cells

    Energy Technology Data Exchange (ETDEWEB)

    Aina, Valentina [Department of Chemistry, Università degli Studi di Torino, Via P. Giuria 7, 10125 Torino (Italy); Centre of Excellence NIS (Nanostructured Interfaces and Surface) Università degli Studi di Torino (Italy); INSTM (Italian National Consortium for Materials Science and Technology), UdR Università di Torino (Italy); Bergandi, Loredana, E-mail: loredana.bergandi@unito.it [Department of Oncology, Università degli Studi di Torino, Via Santena 5/bis, 10126 Torino (Italy); Lusvardi, Gigliola; Malavasi, Gianluca [Department of Chemical and Geological Sciences, Università di Modena and Reggio Emilia, Via Campi 183, 41125 Modena (Italy); Imrie, Flora E.; Gibson, Iain R. [School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD (United Kingdom); Cerrato, Giuseppina [Department of Chemistry, Università degli Studi di Torino, Via P. Giuria 7, 10125 Torino (Italy); Centre of Excellence NIS (Nanostructured Interfaces and Surface) Università degli Studi di Torino (Italy); INSTM (Italian National Consortium for Materials Science and Technology), UdR Università di Torino (Italy); Ghigo, Dario [Department of Oncology, Università degli Studi di Torino, Via Santena 5/bis, 10126 Torino (Italy)

    2013-04-01

    A series of Sr-substituted hydroxyapatites (HA), of general formula Ca{sub (10−x)}Sr{sub x}(PO{sub 4}){sub 6}(OH){sub 2}, where x = 2 and 4, were synthesized by solid state methods and characterized extensively. The reactivity of these materials in cell culture medium was evaluated, and the behavior towards MG-63 osteoblast cells (in terms of cytotoxicity and proliferation assays) was studied. Future in vivo studies will give further insights into the behavior of the materials. A paper by Lagergren et al. (1975), concerning Sr-substituted HA prepared by a solid state method, reports that the presence of Sr in the apatite composition strongly influences the apatite diffraction patterns. Zeglinsky et al. (2012) investigated Sr-substituted HA by ab initio methods and Rietveld analyses and reported changes in the HA unit cell volume and shape due to the Sr addition. To further clarify the role played by the addition of Sr on the physico-chemical properties of these materials we prepared Sr-substituted HA compositions by a solid state method, using different reagents, thermal treatments and a multi-technique approach. Our results indicated that the introduction of Sr at the levels considered here does influence the structure of HA. There is also evidence of a decrease in the crystallinity degree of the materials upon Sr addition. The introduction of increasing amounts of Sr into the HA composition causes a decrease in the specific surface area and an enrichment of Sr-apatite phase at the surface of the samples. Bioactivity tests show that the presence of Sr causes changes in particle size and/or morphology during soaking in MEM solution; on the contrary the morphology of pure HA does not change after 14 days of reaction. The presence of Sr, as Sr-substituted HA and SrCl{sub 2,} in cultures of human MG-63 osteoblasts did not produce any cytotoxic effect. In fact, Sr-substituted HA increased the proliferation of osteoblast cells and enhanced cell differentiation: Sr in

  20. Sr-containing hydroxyapatite: morphologies of HA crystals and bioactivity on osteoblast cells

    International Nuclear Information System (INIS)

    Aina, Valentina; Bergandi, Loredana; Lusvardi, Gigliola; Malavasi, Gianluca; Imrie, Flora E.; Gibson, Iain R.; Cerrato, Giuseppina; Ghigo, Dario

    2013-01-01

    A series of Sr-substituted hydroxyapatites (HA), of general formula Ca (10−x) Sr x (PO 4 ) 6 (OH) 2 , where x = 2 and 4, were synthesized by solid state methods and characterized extensively. The reactivity of these materials in cell culture medium was evaluated, and the behavior towards MG-63 osteoblast cells (in terms of cytotoxicity and proliferation assays) was studied. Future in vivo studies will give further insights into the behavior of the materials. A paper by Lagergren et al. (1975), concerning Sr-substituted HA prepared by a solid state method, reports that the presence of Sr in the apatite composition strongly influences the apatite diffraction patterns. Zeglinsky et al. (2012) investigated Sr-substituted HA by ab initio methods and Rietveld analyses and reported changes in the HA unit cell volume and shape due to the Sr addition. To further clarify the role played by the addition of Sr on the physico-chemical properties of these materials we prepared Sr-substituted HA compositions by a solid state method, using different reagents, thermal treatments and a multi-technique approach. Our results indicated that the introduction of Sr at the levels considered here does influence the structure of HA. There is also evidence of a decrease in the crystallinity degree of the materials upon Sr addition. The introduction of increasing amounts of Sr into the HA composition causes a decrease in the specific surface area and an enrichment of Sr-apatite phase at the surface of the samples. Bioactivity tests show that the presence of Sr causes changes in particle size and/or morphology during soaking in MEM solution; on the contrary the morphology of pure HA does not change after 14 days of reaction. The presence of Sr, as Sr-substituted HA and SrCl 2, in cultures of human MG-63 osteoblasts did not produce any cytotoxic effect. In fact, Sr-substituted HA increased the proliferation of osteoblast cells and enhanced cell differentiation: Sr in HA has a positive effect

  1. Production of Poly(ε-Caprolactone)/Hydroxyapatite Composite Scaffolds with a Tailored Macro/Micro-Porous Structure, High Mechanical Properties, and Excellent Bioactivity.

    Science.gov (United States)

    Kim, Jong-Woo; Shin, Kwan-Ha; Koh, Young-Hag; Hah, Min Jin; Moon, Jiyoung; Kim, Hyoun-Ee

    2017-09-22

    We produced poro-us poly(ε-caprolactone) (PCL)/hydroxyapatite (HA) composite scaffolds for bone regeneration, which can have a tailored macro/micro-porous structure with high mechanical properties and excellent in vitro bioactivity using non-solvent-induced phase separation (NIPS)-based 3D plotting. This innovative 3D plotting technique can create highly microporous PCL/HA composite filaments by inducing unique phase separation in PCL/HA solutions through the non-solvent-solvent exchange phenomenon. The PCL/HA composite scaffolds produced with various HA contents (0 wt %, 10 wt %, 15 wt %, and 20 wt %) showed that PCL/HA composite struts with highly microporous structures were well constructed in a controlled periodic pattern. Similar levels of overall porosity (~78 vol %) and pore size (~248 µm) were observed for all the PCL/HA composite scaffolds, which would be highly beneficial to bone tissue regeneration. Mechanical properties, such as ultimate tensile strength and compressive yield strength, increased with an increase in HA content. In addition, incorporating bioactive HA particles into the PCL polymer led to remarkable enhancements in in vitro apatite-forming ability.

  2. A novel biomagnetic nanoparticle based on hydroxyapatite

    International Nuclear Information System (INIS)

    Wu, H-C; Wang, T-W; Sun, J-S; Wang, W-H; Lin, F-H

    2007-01-01

    In the present study, magnetic HAP was synthesized at different ratios of Fe:Ca (X Fe/Ca ) by the co-precipitation method. We have evaluated the present essential properties including the crystal structure and cell parameters by XRD, lattice arrangement by HR-TEM, composition analysis by ICP-MS, and functional groups by FTIR. The morphology and magnetization were investigated by SEM and AFM and SQUID, respectively. The in vitro biocompatibility was also investigated with a lactate dehydrogenase assay. The results showed that the crystal and molecular structure of the synthesized magnetic-HAP nanoparticle remained unaltered without collapse with the addition of iron ions. The lattice constants of m-HAP were similar to reference JCPDS card no. 9-432. The magnetization of m-HAP nanoparticles increased with increasing X Fe/Ca and possessed the superparamagnetic property with size distribution around 20 nm. The hydroxyapatite-based magnetic nanoparticles were also examined with good biocompatibility. With the appropriate physico-chemical and biological properties, the magnetic-HAP nanoparticles would have great potential to be applied in biomedical applications

  3. Effect of pores formation process and oxygen plasma treatment to hydroxyapatite formation on bioactive PEEK prepared by incorporation of precursor of apatite.

    Science.gov (United States)

    Yabutsuka, Takeshi; Fukushima, Keito; Hiruta, Tomoko; Takai, Shigeomi; Yao, Takeshi

    2017-12-01

    When bioinert substrates with fine-sized pores are immersed in a simulated body fluid (SBF) and the pH value or the temperature is increased, fine particles of calcium phosphate, which the authors denoted as 'precursor of apatite' (PrA), are formed in the pores. By this method, hydroxyapatite formation ability can be provided to various kinds of bioinert materials. In this study, the authors studied fabrication methods of bioactive PEEK by using the above-mentioned process. First, the fine-sized pores were formed on the surface of the PEEK substrate by H 2 SO 4 treatment. Next, to provide hydrophilic property to the PEEK, the surfaces of the PEEK were treated with O 2 plasma. Finally, PrA were formed in the pores by the above-mentioned process, which is denoted as 'Alkaline SBF' treatment, and the bioactive PEEK was obtained. By immersing in SBF with the physiological condition, hydroxyapatite formation was induced on the whole surface of the substrate within 1day. The formation of PrA directly contributed to hydroxyapatite formation ability. By applying the O 2 plasma treatment, hydroxyapatite formation was uniformly performed on the whole surface of the substrate. The H 2 SO 4 treatment contributed to a considerable enhancement of adhesive strength of the formed hydroxyapatite layer formed in SBF because of the increase of surface areas of the substrate. As a comparative study, the sandblasting method was applied as the pores formation process instead of the H 2 SO 4 treatment. Although hydroxyapatite formation was provided also in this case, however, the adhesion of the formed hydroxyapatite layer to the substrate was not sufficient even if the O 2 plasma treatment was conducted. This result indicates that the fine-sized pores should be formed on the whole surface of the substrate uniformly to achieve high adhesive strength of the hydroxyapatite layer. Therefore, it is considered that the H 2 SO 4 treatment before the O 2 plasma and the 'Alkaline SBF' treatment

  4. Rapid Obtaining of Nano-Hydroxyapatite Bioactive Films on NiTi Shape Memory Alloy by Electrodeposition Process

    Science.gov (United States)

    Lobo, A. O.; Otubo, J.; Matsushima, J. T.; Corat, E. J.

    2011-07-01

    Nano-hydroxyapatite (n-HA) crystalline films have been developed in this study by electrodeposition method on NiTi shape memory alloy (SMA). The electrodeposition of the n-HA films was carried out using 0.042 mol/L Ca(NO3)2 · 4H2O + 0.025 mol/L (NH4) · 2HPO4 electrolytes by applying a constant potential of -2.0 V for 120 min and keeping the solution temperature at 70 °C. The characterization of n-HA films is of special importance since bioactive properties related to n-HA have been directly identified with its specific composition and crystalline structure. AFM, XRD, EDX, FEG-SEM and Raman spectroscopy shows a homogeneous film, with high crystallinity, special composition, and bioactivity properties (Ca/P = 1.93) of n-HA on NiTi SMA surfaces. The n-HA coating with special structure would benefit the use of NiTi alloy in orthopedic applications.

  5. Characterization of new bioactive coatings of hydroxyapatite and TiO2 obtained by High-Velocity Oxy-Fuel

    International Nuclear Information System (INIS)

    Melero, H.; Fernandez, J.; Dosta, S.; Guilemany, J. M.

    2011-01-01

    Hydroxyapatite (Hap: Ca 1 0(PO 4 ) 6 OH 2 ) is a biocompatible and bioactive ceramic material widely used as a coating on metal surfaces (dental implants, hip replacements ...), but the low adhesion between Hap and the substrate, due to differences in thermal expansion coefficients of both (very important in thermal spraying because of the fast cooling of the coating, which can produce a lost of adherence), and the degradation of Hap, have been tried to be improved through the incorporation of TiO 2 to get a good combination of mechanical properties. Therefore, the objective of this project is to produce coatings of Hap 80% TiO 2 and 20% (by weight) on Ti6Al4V by High-Speed Thermal Spray (HVOF). The study of the microstructure has been carried out using scanning electron microscopy and characterization of the crystalline phases by X-ray diffraction and Raman spectrometry. The coatings adhesion has been measured by tensile tests according to ASTM C633-01 (2008), and their bioactivity also has been evaluated through its immersion in simulated body fluid (SBF), in order to measure their capacity to form an apatite layer on their surface. (Author) 26 refs.

  6. Enhancement of bioactivity of titanium carbonitride nanocomposite thin films on steels with biosynthesized hydroxyapatite.

    Science.gov (United States)

    Thampi, V V Anusha; Dhandapani, P; Manivasagam, Geetha; Subramanian, B

    2015-01-01

    Thin films of titanium carbonitride (TiCN) were fabricated by DC magnetron sputtering on medical grade steel. The biocompatibility of the coating was further enhanced by growing hydroxyapatite crystals over the TiCN-coated substrates using biologically activated ammonia from synthetic urine. The coatings were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy (SEM)-energy dispersive spectroscopy, and Raman spectroscopy. The electrochemical behavior of the coatings was determined in simulated body fluid. In addition, hemocompatibility was assessed by monitoring the attachment of platelets on the coating using SEM. The wettability of the coatings was measured in order to correlate with biocompatibility results. Formation of a coating with granular morphology and the preferred orientation was confirmed by SEM and X-ray diffraction results. The hydroxyapatite coating led to a decrease in thrombogenicity, resulting in controlled blood clot formation, hence demonstrating the hemocompatibility of the coating.

  7. Thin Bioactive Zn Substituted Hydroxyapatite Coating Deposited on Ultrafine Grained Titanium Substrate: Structure Analysis

    Science.gov (United States)

    Prosolov, Konstantin A.; Belyavskaya, Olga A.; Muehle, Uwe; Sharkeev, Yurii P.

    2018-02-01

    Nanocrystalline Zn substituted hydroxyapatite coatings were deposited by radiofrequency magnetron sputtering on the surface of ultrafine-grained titanium substrates. Cross section transmission electron microscopy provided information about the morphology and texture of the thin film while in-column energy dispersive X-ray analysis confirmed the presence of Zn in the coating. The Zn substituted hydroxyapatite coating was formed by an equiaxed polycrystalline grain structure. Effect of substrate crystallinity on the structure of deposited coating is discussed. An amorphous TiO2 sublayer of 8 nm thickness was detected in the interface between the polycrystalline coating and the Ti substrate. Its appearance in the amorphous state is attributed to prior to deposition etching of the substrate and subsequent condensation of oxygen-containing species sputtered from the target. This layer contributes to the high coating-to-substrate adhesion. The major P-O vibrational modes of high intensity were detected by Raman spectroscopy. The Zn substituted hydroxyapatite could be a material of choice when antibacterial osteoconductive coating with a possibility of withstanding mechanical stress during implantation and service is needed.

  8. Thin Bioactive Zn Substituted Hydroxyapatite Coating Deposited on Ultrafine-Grained Titanium Substrate: Structure Analysis

    Directory of Open Access Journals (Sweden)

    Konstantin A. Prosolov

    2018-02-01

    Full Text Available Nanocrystalline Zn-substituted hydroxyapatite coatings were deposited by radiofrequency magnetron sputtering on the surface of ultrafine-grained titanium substrates. Cross-section transmission electron microscopy provided information about the morphology and texture of the thin film while in-column energy dispersive X-ray analysis confirmed the presence of Zn in the coating. The Zn-substituted hydroxyapatite coating was formed by an equiaxed polycrystalline grain structure. Effect of substrate crystallinity on the structure of deposited coating is discussed. An amorphous TiO2 sublayer of 8-nm thickness was detected in the interface between the polycrystalline coating and the Ti substrate. Its appearance in the amorphous state is attributed to prior to deposition etching of the substrate and subsequent condensation of oxygen-containing species sputtered from the target. This layer contributes to the high coating-to-substrate adhesion. The major P–O vibrational modes of high intensity were detected by Raman spectroscopy. The Zn-substituted hydroxyapatite could be a material of choice when antibacterial osteoconductive coating with a possibility of withstanding mechanical stress during implantation and service is needed.

  9. Bioactive and Antibacterial Coatings Based on Zein/Bioactive Glass Composites by Electrophoretic Deposition

    Directory of Open Access Journals (Sweden)

    Nima Meyer

    2018-01-01

    Full Text Available This study investigated the electrophoretic deposition (EPD of the natural polymer zein combined with bioactive glass (BG particles. Through the deposition of various BG compositions, namely 45S5 BG and Cu-doped BG, this work sought to demonstrate the ability of the films to potentiate the formation of hydroxyapatite (HA in contact with simulated body fluid (SBF. Following incubation in SBF, the physical and chemical surface properties of the EPD films were evaluated using different characterization techniques. The formation of HA at the surface of the coatings following immersion in SBF was confirmed using Fourier transform infrared spectroscopy (FTIR. The results demonstrated HA formation in all coatings after seven days of immersion in SBF. Coating morphology and degradation of the zein films were characterized using environmental scanning electron microscopy (ESEM. The results confirmed EPD as a very convenient room temperature technique for production of ion releasing, bioactive, and antibacterial coatings for potential application in orthopedics.

  10. Enhancement of bioactivity of titanium carbonitride nanocomposite thin films on steels with biosynthesized hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Thampi VV

    2015-10-01

    Full Text Available VV Anusha Thampi,1 P Dhandapani,2 Geetha Manivasagam, B Subramanian11Electrochemical Materials Science Division, Central Electrochemical Research Institute, Karaikudi, 2Corrosion and Materials Protection Division, Central Electrochemical Reserach Institute, Karaikudi, 3Centre for Bio-Materials Science and Technology, VIT University, Vellore, IndiaAbstract: Thin films of titanium carbonitride (TiCN were fabricated by DC magnetron sputtering on medical grade steel. The biocompatibility of the coating was further enhanced by growing hydroxyapatite crystals over the TiCN-coated substrates using biologically activated ammonia from synthetic urine. The coatings were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy (SEM-energy dispersive spectroscopy, and Raman spectroscopy. The electrochemical behavior of the coatings was determined in simulated body fluid. In addition, hemocompatibility was assessed by monitoring the attachment of platelets on the coating using SEM. The wettability of the coatings was measured in order to correlate with biocompatibility results. Formation of a coating with granular morphology and the preferred orientation was confirmed by SEM and X-ray diffraction results. The hydroxyapatite coating led to a decrease in thrombogenicity, resulting in controlled blood clot formation, hence demonstrating the hemocompatibility of the coating.Keywords: titanium carbonitride thin films, magnetron sputtering, ureolytic bacteria, biocompatibility

  11. Synthesis and In Vitro Activity Assessment of Novel Silicon Oxycarbide-Based Bioactive Glasses

    Directory of Open Access Journals (Sweden)

    Isabel Gonzalo-Juan

    2016-11-01

    Full Text Available Novel bioactive glasses based on a Ca- and Mg-modified silicon oxycarbide (SiCaMgOC were prepared from a polymeric single-source precursor, and their in vitro activity towards hydroxyapatite mineralization was investigated upon incubating the samples in simulated body fluid (SBF at 37 °C. The as-prepared materials exhibit an outstanding resistance against devitrification processes and maintain their amorphous nature even after exposure to 1300 °C. The X-ray diffraction (XRD analysis of the SiCaMgOC samples after the SBF test showed characteristic reflections of apatite after only three days, indicating a promising bioactivity. The release kinetics of the Ca2+ and Mg2+ and the adsorption of H+ after immersion of SiCaMgOC in simulated body fluid for different soaking times were analyzed via optical emission spectroscopy. The results show that the mechanism of formation of apatite on the surface of the SiCaMgOC powders is similar to that observed for standard (silicate bioactive glasses. A preliminary cytotoxicity investigation of the SiOC-based bioactive glasses was performed in the presence of mouse embryonic fibroblasts (MEF as well as human embryonic kidney cells (HEK-293. Due to their excellent high-temperature crystallization resistance in addition to bioactivity, the Ca- and Mg-modified SiOC glasses presented here might have high potential in applications related to bone repair and regeneration.

  12. A clinical study on the efficacy of hydroxyapatite - Bioactive glass composite granules in the management of periodontal bony defects

    Directory of Open Access Journals (Sweden)

    Tirthankar Debnath

    2014-01-01

    Full Text Available Background: In periodontal regeneration, several alloplastic materials are being used with a goal to reconstruct new osseous tissue in the infrabony defect sites. The present study was undertaken to evaluate the efficacy of hydroxyapatite-bioactive glass (HA:BG composite granules in the management of periodontal bony defects. Materials and Methods: A randomized control study was conducted. Subjects with infrabony defects were divided into three groups. Test Group 1 (n = 10: Defect site was treated with HA:BG, with a biodegradable membrane. Test Group 2 (n = 10: Defect site was treated with HAP, with a biodegradable membrane. Control group (n = 10: Defect site was treated with open flap debridement with a biodegradable membrane Results: The healing of defects was uneventful and free of any biological complications. The gain in clinical attachment level, reduction of probing pocket depth, and defect fill were statistically significant in all three groups. TG1 sites showed significant defect fill than TG2 and CG sites. Conclusion: The performance of HA:BG was better compared to HAP and open flap debridement for the reconstruction of infrabony defects.

  13. Electrochemical corrosion and bioactivity of Ti-Nb-Sn-hydroxyapatite composites fabricated by pulse current activated sintering.

    Science.gov (United States)

    Xiaopeng, Wang; Fantao, Kong; Biqing, Han; Yuyong, Chen

    2017-11-01

    Ti-Nb-Sn-hydroxyapatite (HA) composites were prepared by mechanical alloying for different times (unmilled, 4, 8 and 12h), followed by pulse current activated sintering. The effects of the milling time on the electrochemical corrosion resistance and bioactivity of the sintered Ti-35Nb-2.5Sn-15HA composites were investigated. Potentiodynamic polarization test results indicated that the sintered Ti-35Nb-2.5Sn-15HA composites exhibited higher corrosion resistance with increasing milling time. The corrosion potential and current of the Ti-35Nb-2.5Sn-15HA composite sintered by 12h milled powders were - 0.261V and 0.18μA/cm 2 , respectively, and this sintered composite showed a stable and wide passivation region. The hemolysis rate of the sintered Ti-35Nb-2.5Sn-15HA composites reduced with increasing milling time and the lowest hemolytic rate of the composites was 0.87%. In addition, the in vitro cell culture results indicated that the composite sintered by 12h milled powders had good biocompatibility. These results indicate the significant potential of Ti-35Nb-2.5Sn/xHA composites for biomedical implant applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles

    Directory of Open Access Journals (Sweden)

    F. A. Sheikh

    2012-01-01

    Full Text Available In the present study, we had introduced polyurethane (PU nanofibers that contain hydroxyapatite (HAp nanoparticles (NPs as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination of bovine bones. Typically, a colloidal gel consisting of HAp/PU had been electrospun to form nanofibers. In this communication, physiochemical aspects of prepared nanofibers were characterized by FE-SEM, TEM and TEM-EDS, which confirmed that nanofibers were well-oriented and good dispersion of HAp NPs, over the prepared nanofibers. Parameters, affecting the utilization of the prepared nanofibers in various nano-biotechnological fields have been studied; for instance, the bioactivity of the produced nanofiber mats was investigated while incubating in simulated body fluid (SBF. The results from incubation of nanofibers, indicated that incorporation of HAp strongly activates the precipitation of the apatite-like particles, because of the HAp NPs act as seed, that accelerate crystallization of the biological HAp from the utilized SBF.

  15. Influence of Porous Spherical-Shaped Hydroxyapatite on Mechanical Strength and Bioactive Function of Conventional Glass Ionomer Cement

    Directory of Open Access Journals (Sweden)

    Szu-Yu Chiu

    2017-01-01

    Full Text Available Glass-ionomer-cement (GIC is helpful in Minimal Intervention Dentistry because it releases fluoride ions and is highly biocompatible. The aim of this study is to investigate the mechanisms by which hydroxyapatite (HAp improves the mechanical strength and bioactive functioning of GIC when these materials are combined to make apatite ionomer cement (AIC. A conventional GIC powder was mixed with porous, spherical-HAp particles (HApS, crystalline HAp (HAp200 or one of two types of cellulose. The micro-compressive strengths of the additive particles were measured, and various specimens were evaluated with regard to their compressive strengths (CS, fluoride release concentrations (fluoride electrode and multi-element release concentrations. The AIC was found to release higher concentrations of fluoride (1.2 times and strontium ions (1.5 times compared to the control GIC. It was detected the more release of calcium originated from HApS than HAp200 in AIC. The CS of the AIC incorporating an optimum level of HAp was also significantly higher than that of the GIC. These results suggest that adding HAp can increase the release concentration of ions required for remineralization while maintaining the CS of the GIC. This effect does not result from a physical phenomenon, but rather from chemical reactions between the HAp and polyacrylic acid of GIC.

  16. Microwave sintering of hydroxyapatite-based composites

    International Nuclear Information System (INIS)

    Fang, Y.; Roy, D.M.; Cheng, J.; Roy, R.; Agrawal, D.K.

    1993-01-01

    Composites of hydroxyapatite/partially stabilized zirconia (HAp/PSZ) and hydroxyapatite/silicon carbide whiskers (HAp/SiC) were sintered at 1100-1200 degrees C by microwave at 2.45 GHz. Characterization of the sintered composites was carried out by density, microstructure, phase composition, and fracture toughness measurements. The results show that although not yet fully densified, a much higher sintered density in the HAp/PSZ composite was achieved by microwave sintering than by conventional sintering at the same temperature. A relative density of 93% was achieved by 20 min. microwave processing at 1200 degrees C. Comparatively, 2 h conventional sintering of the same material at 1200 degrees C led to only 75.5% relative density. K IC of this microwave sintered HAp/PSZ of 93% density was found to be 3.88 MPa√m, which is 250% of the value for pure HAp of the same density. A further increase in K IC could be expected if full or nearly full densification was achieved. Sintering of PSZ particles in the HAp/PSZ composite was also observed in the microwave processed sample. Microwave sintering of HAp/SiC was not successful in the current study due to the oxidation of SiC in air at high temperature. 8 refs., 4 figs., 1 tab

  17. In vitro and in vivo bioactivity assessment of a polylactic acid/hydroxyapatite composite for bone regeneration

    NARCIS (Netherlands)

    Danoux, Charlene; Barbieri, D.; Yuan, Huipin; de Bruijn, Joost Dick; van Blitterswijk, Clemens; Habibovic, Pamela

    2014-01-01

    Synthetic bone graft substitutes based on composites consisting of a polymer and a calcium-phosphate (CaP) ceramic are developed with the aim to satisfy both mechanical and bioactivity requirements for successful bone regeneration. In the present study, we have employed extrusion to produce a

  18. Fabrication and formation of bioactive anodic zirconium oxide nanotubes containing presynthesized hydroxyapatite via alternative immersion method

    International Nuclear Information System (INIS)

    Wang Luning; Luo Jingli

    2011-01-01

    Hydroxyapatite (HA) coating has been widely applied on metallic biomedical implants to enhance their biocompatibility. It has been reported that HA coating can be formed on annealed zirconium with anodic zirconium oxide nanotubular arrays after immersion in simulated biological fluid (SBF) for about 14 days. In the present study, we apply an alternative immersion method (AIM) to form presynthesized HA on ZrO 2 nanotubes. The AIM-treated specimen was then moved to the SBF to evaluate the capability for the formation of HA on it. The HA coating formed after only 2 days immersion and thickened after 5 days in the SBF. The HA coating is the carbonated HA with a ratio of Ca to P of about 1.4, similar to the physiological HA containing other minor elements such as Mg and Na. The results demonstrate that the AIM treatment is indeed suitable for the zirconium oxide nanotubes and highly accelerates the formation of HA coating in comparison with the existing methods, i.e. the annealing of the as-formed zirconium oxide nanotubular arrays.

  19. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Cijun Shuai

    2017-03-01

    Full Text Available Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  20. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting.

    Science.gov (United States)

    Shuai, Cijun; Zhou, Yuanzhuo; Yang, Youwen; Feng, Pei; Liu, Long; He, Chongxian; Zhao, Mingchun; Yang, Sheng; Gao, Chengde; Wu, Ping

    2017-03-17

    Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA) was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  1. Bioactivity and electrochemical behavior of hydroxyapatite-silicon-multi walled carbon nano-tubes composite coatings synthesized by EPD on NiTi alloys in simulated body fluid

    Energy Technology Data Exchange (ETDEWEB)

    Khalili, V., E-mail: V_khalili@sut.ac.ir [Department of Materials Engineering, Engineering Faculty, University of Bonab, Bonab (Iran, Islamic Republic of); Khalil-Allafi, J. [Research Center for Advanced Materials and Mineral Processing, Faculty of Materials Engineering, Sahand University of Technology, Tabriz (Iran, Islamic Republic of); Frenzel, J.; Eggeler, G. [Institute for Materials, Faculty of Mechanical Engineering, Ruhr-University Bochum, 44801 Bochum (Germany)

    2017-02-01

    In order to improve the surface bioactivity of NiTi bone implant and corrosion resistance, hydroxyapatite coating with addition of 20 wt% silicon, 1 wt% multi walled carbon nano-tubes and both of them were deposited on a NiTi substrate using a cathodic electrophoretic method. The apatite formation ability was estimated using immersion test in the simulated body fluid for 10 days. The SEM images of the surface of coatings after immersion in simulated body fluid show that the presence of silicon in the hydroxyapatite coatings accelerates in vitro growth of apatite layer on the coatings. The Open-circuit potential and electrochemical impedance spectroscopy were measured to evaluate the electrochemical behavior of the coatings in the simulated body fluid at 37 °C. The results indicate that the compact structure of hydroxyapatite-20 wt% silicon and hydroxyapatite-20 wt% silicon-1 wt% multi walled carbon nano-tubes coatings could efficiently increase the corrosion resistance of NiTi substrate. - Highlights: • The composite coatings of HA, Si and MWCNTs was prepared using electrophoretic deposition. • The presence of 1 wt.% MWCNTs in the HA coating provides more nucleation cites of apatite crystallites in SBF. • The presence of Si in HA coating increases the growth rate of apatite crystallites with the Ca/P atomic ratio of 1.67. • The EIS indicate the compact HA-20%Si and HA-20%Si-1%MWCNTs coatings efficiently increase corrosion resistance of NiTi. • The porous HA and HA-1%MWCNTs do not increase significantly corrosion resistance due to the easy diffusion path.

  2. Hydroxyapatite based 99Mo-99mTc and 188W-188Re generator systems

    International Nuclear Information System (INIS)

    Monroy-Guzman, F.; Badillo-Almaraz, V.E.; Flores de la Torre, J.A.; Cosgrove, J.; Knapp, F.F. Jr.

    2007-01-01

    This paper describes studies evaluating the use of hydroxyapatite as the adsorbent material for both 90M o- 90m Tc and 89W - 188 Re generator systems. Hydroxyapatite is an insoluble solid with anion exchange properties. A study of the sorption behaviour of 90M o, 90m Tc, 188 W and 188 Re on hydroxyapatite in NaCl medium was evaluated by batch experiments. The results demonstrated that while 90M o, 90m Tc and 188 Re are not adsorbed by the hydroxyapatite in NaCl solutions (Kd 89W is strongly adsorbed (Kd >500). On the basis of these measurements, hydroxyapatite 89W - 188 Re generator systems were then constructed and eluted in NaCl solutions. The hydroxyapatite based 89W - 188 Re generator performances are presented. (author)

  3. In vitro and in vivo evaluations of nano-hydroxyapatite/polyamide 66/glass fibre (n-HA/PA66/GF as a novel bioactive bone screw.

    Directory of Open Access Journals (Sweden)

    Bao Su

    Full Text Available In this study, we prepared nano-hydroxyapatite/polyamide 66/glass fibre (n-HA/PA66/GF bioactive bone screws. The microstructure, morphology and coating of the screws were characterised, and the adhesion, proliferation and viability of MC3T3-E1 cells on n-HA/PA66/GF scaffolds were determined using scanning electron microscope, CCK-8 assays and cellular immunofluorescence analysis. The results confirmed that n-HA/PA66/GF scaffolds were biocompatible and had no negative effect on MC3T3-E1 cells in vitro. To investigate the in vivo biocompatibility, internal fixation properties and osteogenesis of the bioactive screws, both n-HA/PA66/GF screws and metallic screws were used to repair intercondylar femur fractures in dogs. General photography, CT examination, micro-CT examination, histological staining and biomechanical assays were performed at 4, 8, 12 and 24 weeks after operation. The n-HA/PA66/GF screws exhibited good biocompatibility, high mechanical strength and extensive osteogenesis in the host bone. Moreover, 24 weeks after implantation, the maximum push-out load of the bioactive screws was greater than that of the metallic screws. As shown by their good cytocompatibility, excellent biomechanical strength and fast formation and ingrowth of new bone, n-HA/PA66/GF screws are thus suitable for orthopaedic clinical applications.

  4. Effect of l-lysine-assisted surface grafting for nano-hydroxyapatite on mechanical properties and in vitro bioactivity of poly(lactic acid-co-glycolic acid).

    Science.gov (United States)

    Liuyun, Jiang; Lixin, Jiang; Chengdong, Xiong; Lijuan, Xu; Ye, Li

    2016-01-01

    It is promising and challenging to study surface modification for nano-hydroxyapatite to improve the dispersion and enhance the mechanical properties and bioactivity of poly(lactic acid-co-glycolic acid). In this paper, we designed an effective new surface grafting with the assist of l-lysine for nano-hydroxyapatite, and the nano-hydroxyapatite surface grafted with the assist of l-lysine (g-nano-hydroxyapatite) was incorporated into poly(lactic acid-co-glycolic acid) to develop a series of g-nano-hydroxyapatite/poly(lactic acid-co-glycolic acid) nano-composites. The surface modification reaction for nano-hydroxyapatite, the mechanical properties, and in vitro human osteoblast-like cell (MG-63) response were characterized and investigated by Fourier transformation infrared, thermal gravimetric analysis, dispersion test, electromechanical universal tester, differential scanning calorimeter measurements, and in vitro cells culture experiment. The results showed that the grafting amount on the surface of nano-hydroxyapatite was enhanced with the increase of l-lysine, and the dispersion of nano-hydroxyapatite was improved more, so that it brought about better promotion crystallization and more excellent mechanical enhancement effect for poly(lactic acid-co-glycolic acid), comparing with the unmodified nano-hydroxyapatite. Moreover, the cells' attachment and proliferation results confirmed that the incorporation of the g-nano-hydroxyapatite into poly(lactic acid-co-glycolic acid) exhibited better biocompatibility than poly(lactic acid-co-glycolic acid). The above results indicated that the new surface grafting with the assist of l-lysine for nano-hydroxyapatite was an ideal novel surface modification method, which brought about better mechanical enhancement effect and in vitro bioactivity for poly(lactic acid-co-glycolic acid) with adding higher g-nano-hydroxyapatite content, suggesting it had a great potential to be used as bone fracture internal fixation materials

  5. Risedronate/zinc-hydroxyapatite based nanomedicine for osteoporosis

    Energy Technology Data Exchange (ETDEWEB)

    Khajuria, Deepak Kumar, E-mail: deepak_kumarkhajuria@yahoo.co.in [Laboratory for Integrative Multiscale Engineering Materials and Systems, Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore 560027 (India); Disha, Choudhary [Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore 560027 (India); Vasireddi, Ramakrishna [Laboratory for Integrative Multiscale Engineering Materials and Systems, Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Razdan, Rema [Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore 560027 (India); Mahapatra, D. Roy [Laboratory for Integrative Multiscale Engineering Materials and Systems, Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2016-06-01

    Targeting of superior osteogenic drugs to bone is an ideal approach for treatment of osteoporosis. Here, we investigated the potential of using risedronate/zinc-hydroxyapatite (ZnHA) nanoparticles based formulation in a rat model of experimental osteoporosis. Risedronate, a targeting moiety that has a strong affinity for bone, was loaded to ZnHA nanoparticles by adsorption method. Prepared risedronate/ZnHA drug formulation was characterized by field-emission scanning electron microscopy, X-ray diffraction analysis and fourier transform infrared spectroscopy. In vivo performance of the prepared risedronate/ZnHA nanoparticles was tested in an experimental model of postmenopausal osteoporosis. Therapy with risedronate/ZnHA drug formulation prevented increase in serum levels of bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase 5b better than risedronate/HA or risedronate. With respect to improvement in the mechanical strength of the femoral mid-shaft and correction of increase in urine calcium and creatinine levels, the therapy with risedronate/ZnHA drug formulation was more effective than risedronate/HA or risedronate therapy. Moreover, risedronate/ZnHA drug therapy preserved the cortical and trabecular bone microarchitecture better than risedronate/HA or risedronate therapy. Furthermore, risedronate/ZnHA drug formulation showed higher values of calcium/phosphorous ratio and zinc content. The results strongly implicate that risedronate/ZnHA drug formulation has a therapeutic advantage over risedronate or risedronate/HA therapy for the treatment of osteoporosis. - Highlights: • Risedronate functionalized zinc-hydroxyapatite nanoparticles were prepared. • Risedronate was used as a carrier to deliver zinc-hydroxyapatite nanoparticles to bones. • Application of risedronate/ZnHA drug formulation in osteoporosis is described.

  6. Development of strontium and magnesium substituted porous hydroxyapatite/poly(3,4-ethylenedioxythiophene) coating on surgical grade stainless steel and its bioactivity on osteoblast cells.

    Science.gov (United States)

    Gopi, D; Ramya, S; Rajeswari, D; Surendiran, M; Kavitha, L

    2014-02-01

    The present study deals with the successful development of bilayer coatings by electropolymerisation of poly(3,4-ethylenedioxythiophene) (PEDOT) on surgical grade stainless steel (316L SS) followed by the electrodeposition of strontium (Sr) and magnesium (Mg) substituted porous hydroxyapatite (Sr, Mg-HA). The bilayer coatings were characterised by Fourier transform infrared spectroscopy (FT-IR) and high resolution scanning electron microscopy (HRSEM). Corrosion resistance of the obtained coatings was investigated in Ringer's solution by electrochemical techniques and the results were in good agreement with those obtained from chemical analysis, namely inductively coupled plasma atomic emission spectrometry (ICP-AES). Also, the mechanical and biological properties of the bilayer coatings were analyzed. From the obtained results it was evident that the PEDOT/Sr, Mg-HA bilayer exhibited greater adhesion strength than the Sr, Mg-HA coated 316L SS. In vitro cell adhesion test of the Sr, Mg-HA coating on PEDOT coated specimen is found to be more bioactive compared to that of the single substituted hydroxyapatite (Sr or Mg-HA) on the PEDOT coated 316L SS. Thus, the PEDOT/Sr, Mg-HA bilayer coated 316L SS can serve as a prospective implant material for biomedical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles

    DEFF Research Database (Denmark)

    Sheikh, F. A.; Kanjwal, Muzafar Ahmed; Macossay, J.

    2012-01-01

    In the present study, we had introduced polyurethane (PU) nanofibers that contain hydroxyapatite (HAp) nanoparticles (NPs) as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination...

  8. Cell Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath

    Science.gov (United States)

    2017-07-01

    to subsequently guide tissue regeneration , for example, by seeded tissue progenitor cells . To achieve this objective, the first step is to develop...AWARD NUMBER: W81XWH-15-1-0104 TITLE: Cell -Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath PRINCIPAL INVESTIGATOR...SUBTITLE 5a. CONTRACT NUMBER Cell -Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath 5b. GRANT NUMBER W81XWH-15-1-0104 5c. PROGRAM

  9. Synthesis and characterization of 64SiO2-26CaO-5P2O5-5CuO bioactive composition for the growth of hydroxyapatite layer by XRD, Raman and pH studies

    Science.gov (United States)

    Kaur, Pardeep; Singh, K. J.

    2016-05-01

    Bioactive sample with the nominal composition of 64SiO2-26CaO-5P2O5-5CuO has been prepared in the laboratory by using the sol-gel technique. The bioactivity of the prepared sample has been analyzed by using the Tris Simulated Body Fluid which has also been prepared in the laboratory. XRD and Raman techniques have been employedto probe the formation of hydroxyapatite layer. pH studies has also been undertaken to check the acidic/non-acidic behavior of sample. Growth of hydroxyapatite layer has been observed after one day on the surface of the sample. Moreover, sample has been observed to be non-acidic in nature.

  10. Synthesis, characterization and study of the bioactivity of B2O3 based bioglass

    Energy Technology Data Exchange (ETDEWEB)

    Alves, L.C.F.; Gomes, J.F.; Portes, P.N.; Steimacher, A.; Pedrochi, F. [Universidade Federal do Maranhao (UFMA), MA (Brazil)

    2016-07-01

    Full text: Replacement of parts of living system by synthetic materials has resulted in the creation of a class of materials known as Biomaterials. The clinical use of glass as a biomaterial came up with the pioneering work of Larry Hench in the 60, with the development of Bioglass 45S5®. The main feature of this biocompatible material is its ability to promote a quick and durable chemical bonding by means of an apatitic interface, with the bone tissue, which earned him the designation of bioactive glass. Its development increased the research about restorations bone materials. The biggest disadvantage presented by bioglasses are the low mechanical strength and low fracture toughness, which have prevented their application in structural implants. Boron has some specific properties such as antiseptic (Borax), mechanical strength and thermal shock (borosilicate) and low toxicity in mammals. Recent studies have shown that the partial or complete replacement of SiO2 in Bioglass® 45S5 by B2O3, leads to a complete and faster conversion of bioglass in Hydroxyapatite. Some research found that Boron based bioglass are favourable substrates for cell attachment and proliferation of osteogenic. The samples of the boron-based bioglass were obtained from the melting-quenching process with the following reagents CaO-B2O3-CaF2-P2O5-Na2O, then were thermally treated so that internal tensions are reduced and the glass get higher mechanical strength. The samples bioactivity is tested in SBF (Simulated Body Fluid) test and the characterization are done before and after this process. The mainly properties studied are: determination of volumetric mass density, differential thermal analysis (DTA) and x-ray diffractometry. The results are discussed in terms of the bioactivity compared to Bioglass® 45S5 and other compositions studied in the literature. (author)

  11. Biocompatibility of hydroxyapatite scaffolds processed by lithography-based additive manufacturing.

    Science.gov (United States)

    Tesavibul, Passakorn; Chantaweroad, Surapol; Laohaprapanon, Apinya; Channasanon, Somruethai; Uppanan, Paweena; Tanodekaew, Siriporn; Chalermkarnnon, Prasert; Sitthiseripratip, Kriskrai

    2015-01-01

    The fabrication of hydroxyapatite scaffolds for bone tissue engineering applications by using lithography-based additive manufacturing techniques has been introduced due to the abilities to control porous structures with suitable resolutions. In this research, the use of hydroxyapatite cellular structures, which are processed by lithography-based additive manufacturing machine, as a bone tissue engineering scaffold was investigated. The utilization of digital light processing system for additive manufacturing machine in laboratory scale was performed in order to fabricate the hydroxyapatite scaffold, of which biocompatibilities were eventually evaluated by direct contact and cell-culturing tests. In addition, the density and compressive strength of the scaffolds were also characterized. The results show that the hydroxyapatite scaffold at 77% of porosity with 91% of theoretical density and 0.36 MPa of the compressive strength are able to be processed. In comparison with a conventionally sintered hydroxyapatite, the scaffold did not present any cytotoxic signs while the viability of cells at 95.1% was reported. After 14 days of cell-culturing tests, the scaffold was able to be attached by pre-osteoblasts (MC3T3-E1) leading to cell proliferation and differentiation. The hydroxyapatite scaffold for bone tissue engineering was able to be processed by the lithography-based additive manufacturing machine while the biocompatibilities were also confirmed.

  12. Cementless Hydroxyapatite Coated Hip Prostheses

    Science.gov (United States)

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  13. Cementless Hydroxyapatite Coated Hip Prostheses

    Directory of Open Access Journals (Sweden)

    Antonio Herrera

    2015-01-01

    Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

  14. Hydroxyapatite coatings for biomedical applications

    CERN Document Server

    Zhang, Sam

    2013-01-01

    Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characteri

  15. Innovative micro-textured hydroxyapatite and poly(l-lactic)-acid polymer composite film as a flexible, corrosion resistant, biocompatible, and bioactive coating for Mg implants.

    Science.gov (United States)

    Kim, Sae-Mi; Kang, Min-Ho; Kim, Hyoun-Ee; Lim, Ho-Kyung; Byun, Soo-Hwan; Lee, Jong-Ho; Lee, Sung-Mi

    2017-12-01

    The utility of a novel ceramic/polymer-composite coating with a micro-textured microstructure that would significantly enhance the functions of biodegradable Mg implants is demonstrated here. To accomplish this, bioactive hydroxyapatite (HA) micro-dots can be created by immersing a Mg implant with a micro-patterned photoresist surface in an aqueous solution containing calcium and phosphate ions. The HA micro-dots can then be surrounded by a flexible poly(l-lactic)-acid (PLLA) polymer using spin coating to form a HA/PLLA micro-textured coating layer. The HA/PLLA micro-textured coating layer showed an excellent corrosion resistance when it was immersed in a simulated body fluid (SBF) solution and good biocompatibility, which was assessed by in vitro cell tests. In addition, the HA/PLLA micro-textured coating layer had high deformation ability, where no apparent changes in the coating layer were observed even after a 5% elongation, which would be unobtainable using HA and PLLA coating layers; furthermore, this allowed the mechanically-strained Mg implant with the HA/PLLA micro-textured coating layer to preserve its excellent corrosion resistance and biocompatibility in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Lecithin-based wet chemical precipitation of hydroxyapatite nanoparticles.

    Science.gov (United States)

    Michał, Wojasiński; Ewa, Duszyńska; Tomasz, Ciach

    Hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 nanoparticles have been successfully synthesized by the wet chemical precipitation method at 60 °C in the presence of biocompatible natural surfactant-lecithin. The composition and morphology of nanoparticles of hydroxyapatite synthesized with lecithin (nHAp-PC) was studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Size distribution for nanoparticles was measured by nanoparticle tracking analysis in NanoSight system. We discuss in details influence of lecithin concentration in reaction system on nHAp-PC morphology, as well as on size distributions and suspendability of nanoparticles. Product exhibits crystalline structure and chemical composition of hydroxyapatite, with visible traces of lecithin. Difference in surfactant amounts results in changes in particles morphology and their average size.

  17. Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study.

    Science.gov (United States)

    Chadda, Harshita; Naveen, Sangeetha Vasudevaraj; Mohan, Saktiswaren; Satapathy, Bhabani K; Ray, Alok R; Kamarul, Tunku

    2016-07-01

    Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail. The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination. Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software. Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis. The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  18. In vitro evaluation of borate-based bioactive glass scaffolds prepared by a polymer foam replication method

    International Nuclear Information System (INIS)

    Fu Hailuo; Fu Qiang; Zhou Nai; Huang Wenhai; Rahaman, Mohamed N.; Wang Deping; Liu Xin

    2009-01-01

    Borate-based bioactive glass scaffolds with a microstructure similar to that of human trabecular bone were prepared using a polymer foam replication method, and evaluated in vitro for potential bone repair applications. The scaffolds (porosity = 72 ± 3%; pore size = 250-500 μm) had a compressive strength of 6.4 ± 1.0 MPa. The bioactivity of the scaffolds was confirmed by the formation of a hydroxyapatite (HA) layer on the surface of the glass within 7 days in 0.02 M K 2 HPO 4 solution at 37 deg. C. The biocompatibility of the scaffolds was assessed from the response of cells to extracts of the dissolution products of the scaffolds, using assays of MTT hydrolysis, cell viability, and alkaline phosphatase activity. For boron concentrations below a threshold value (0.65 mM), extracts of the glass dissolution products supported the proliferation of bone marrow stromal cells, as well as the proliferation and function of murine MLO-A5 cells, an osteogenic cell line. Scanning electron microscopy showed attachment and continuous increase in the density of MLO-A5 cells cultured on the surface of the glass scaffolds. The results indicate that borate-based bioactive glass could be a potential scaffold material for bone tissue engineering provided that the boron released from the glass could be controlled below a threshold value.

  19. Sphingoid bases inhibit acid-induced demineralization of hydroxyapatite

    NARCIS (Netherlands)

    Valentijn-Benz, M.; van 't Hof, W.; Bikker, F.J.; Nazmi, K.; Brand, H.S.; Sotres, J.; Lindh, L.; Arnebrant, T.; Veerman, E.C.I.

    2015-01-01

    Calcium hydroxyapatite (HAp), the main constituent of dental enamel, is inherently susceptible to the etching and dissolving action of acids, resulting in tooth decay such as dental caries and dental erosion. Since the prevalence of erosive wear is gradually increasing, there is urgent need for

  20. Development of hydroxyapatite-based nanomaterials to enhance ...

    African Journals Online (AJOL)

    Purpose: To develop a novel chitosan/gelatin-hydroxyapatite (CGHaP) microspheres for evaluating the biological response of pre-osteoblast cells. Methods: The microsphere was prepared by water-in-oil emulsion method. Cell proliferation was studied using AlamarBlue colorimetric assay and DAPI staining while alkaline ...

  1. Bioactivation of calcium deficient hydroxyapatite with foamed gelatin gel. A new injectable self-setting bone analogue.

    Science.gov (United States)

    Dessì, M; Alvarez-Perez, M A; De Santis, R; Ginebra, M P; Planell, J A; Ambrosio, L

    2014-02-01

    An alternative approach to bone repair for less invasive surgical techniques, involves the development of biomaterials directly injectable into the injury sites and able to replicate a spatially organized platform with features of bone tissue. Here, the preparation and characterization of an innovative injectable bone analogue made of calcium deficient hydroxyapatite and foamed gelatin is presented. The biopolymer features and the cement self-setting reaction were investigated by rheological analysis. The porous architecture, the evolution of surface morphology and the grains dimension were analyzed with electron microscopy (SEM/ESEM/TEM). The physico-chemical properties were characterized by X-ray diffraction and FTIR analysis. Moreover, an injection test was carried out to prove the positive effect of gelatin on the flow ensuing that cement is fully injectable. The cement mechanical properties are adequate to function as temporary substrate for bone tissue regeneration. Furthermore, MG63 cells and bone marrow-derived human mesenchymal stem cells (hMSCs) were able to migrate and proliferate inside the pores, and hMSCs differentiated to the osteoblastic phenotype. The results are paving the way for an injectable bone substitute with properties that mimic natural bone tissue allowing the successful use as bone filler for craniofacial and orthopedic reconstructions in regenerative medicine.

  2. In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants

    Energy Technology Data Exchange (ETDEWEB)

    Sutha, S.; Kavitha, K.; Karunakaran, G.; Rajendran, V., E-mail: veerajendran@gmail.com

    2013-10-15

    A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58–1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Highlights: • Hydroxyapatite particles are prepared with various silicon concentration • Prepared composites are blended with chitosan and coated on the implant • Corrosion resistance in simulated body fluid improves its stability • Increase in silicon concentration improves the antibacterial activity • Coated plate exhibit high in-vitro bioactivity in simulated body fluid.

  3. In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants

    International Nuclear Information System (INIS)

    Sutha, S.; Kavitha, K.; Karunakaran, G.; Rajendran, V.

    2013-01-01

    A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58–1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Highlights: • Hydroxyapatite particles are prepared with various silicon concentration • Prepared composites are blended with chitosan and coated on the implant • Corrosion resistance in simulated body fluid improves its stability • Increase in silicon concentration improves the antibacterial activity • Coated plate exhibit high in-vitro bioactivity in simulated body fluid

  4. Enhancing the bioactivity of Poly(lactic-co-glycolic acid scaffold with a nano-hydroxyapatite coating for the treatment of segmental bone defect in a rabbit model

    Directory of Open Access Journals (Sweden)

    Wang DX

    2013-05-01

    the group of virgin PLGA scaffolds, as shown by X-ray, Micro-computerized tomography and histological examinations.Conclusion: nHA coating on the interior pore surfaces can significantly improve the bioactivity of PLGA porous scaffolds.Keywords: PLGA, nano-hydroxyapatite, bone tissue engineering, BMSCs, bone defect

  5. Novel and facile microwave-assisted synthesis of Mo-doped hydroxyapatite nanorods: Characterization, gamma absorption coefficient, and bioactivity.

    Science.gov (United States)

    Abutalib, M M; Yahia, I S

    2017-09-01

    In the current work, the authors report the microwave-assisted synthesis Molybdenum-doped (from 0.05 to 5wt%) hydroxyapatite (HAp) for the first time. The morphology of Mo-doped HAp is nanorods of diameter in the range of 25-70nm and length in the range of 25nm to 200nm. The good crystalline nature was confirmed from X-ray diffraction patterns and also lattice parameters, grain size, strain and dislocation density were determined. The crystallite size was found to be in the range 16 to 30nm and crystallinity was found to be enhanced from 0.5 to 0.7 with doping. The field emission SEM micrographs show that the morphology of the synthesized nanostructures of pure and Mo-doped HAp are nanorods of few nanometers. The vibrational modes were identified using the FT-Raman and FT-IR spectroscopy. The dielectric properties were studied and the AC electrical conductivity was found to be increased with increasing the concentration of Mo ions doping in HAp. Moreover, antimicrobial studies were also carried out to understand the anti-bacterial and anti-fungi properties. The results suggest that it may be a good bio-ceramics material for bio-medical applications. Mo-doped HAp was subjected to the gamma irradiation produced from Cs-137 (662keV) and its related parameters such as linear absorption coefficient, the half-value layer (HVL) and the tenth value layer TVL were calculated and analyzed. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Stem cell homing-based tissue engineering using bioactive materials

    Science.gov (United States)

    Yu, Yinxian; Sun, Binbin; Yi, Chengqing; Mo, Xiumei

    2017-06-01

    Tissue engineering focuses on repairing tissue and restoring tissue functions by employing three elements: scaffolds, cells and biochemical signals. In tissue engineering, bioactive material scaffolds have been used to cure tissue and organ defects with stem cell-based therapies being one of the best documented approaches. In the review, different biomaterials which are used in several methods to fabricate tissue engineering scaffolds were explained and show good properties (biocompatibility, biodegradability, and mechanical properties etc.) for cell migration and infiltration. Stem cell homing is a recruitment process for inducing the migration of the systemically transplanted cells, or host cells, to defect sites. The mechanisms and modes of stem cell homing-based tissue engineering can be divided into two types depending on the source of the stem cells: endogenous and exogenous. Exogenous stem cell-based bioactive scaffolds have the challenge of long-term culturing in vitro and for endogenous stem cells the biochemical signal homing recruitment mechanism is not clear yet. Although the stem cell homing-based bioactive scaffolds are attractive candidates for tissue defect therapies, based on in vitro studies and animal tests, there is still a long way before clinical application.

  7. Development and Characterization of Sr-Containing Glass-Ceramic Composites Based on Biogenic Hydroxyapatite

    Science.gov (United States)

    Kuda, Oleksii; Pinchuk, Nataliia; Bykov, Oleksandr; Tomila, Tamara; Olifan, Olena; Golovkova, Maryna

    2018-05-01

    Composite materials based on hydroxyapatite are widely used for bone tissue engineering. There is evidence of a positive effect of the presence of strontium in osteoplastic materials in the case of a Ca/Sr certain ratio. To examine the effect of the addition of Sr2+, a study was made by introducing it into the material composition based on biogenic hydroxyapatite and sodium borosilicate glass (50/50% wt.). The strontium was introduced into the composition in an amount of 1% wt. Composite materials were obtained at final sintering temperatures of 780 °C and a sintering time of 1 h. The effect of additions of glass phase and strontium affect changes in the crystal lattice of biogenic hydroxyapatite was investigated with the help of X-ray phase analysis, IR spectroscopy. Also the behavior of composites in vitro in physiological solution was studied.

  8. Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Hesaraki, S., E-mail: S-hesaraki@merc.ac.ir

    2016-06-01

    This paper reports on strong and bioactive bone cement based on ternary bioactive SiO{sub 2}-CaO-P{sub 2}O{sub 5} glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~ 32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption. - Highlights: • Light cure cement based on SiO{sub 2}-CaO-P{sub 2}O{sub 5} glass and polymer-like matrix was formed. • The matrix includes poly(acrylic/maleic acid) and poly(hydroxyethyl methacrylate). • The cement is as strong as polymethylmethacrylate bone cement. • The cement exhibits apatite formation ability in simulated body fluid. • The cement is biodegradable and supports proliferation of osteoblastic cells.

  9. Treatment of Lateral Tibial Condylar Fractures Using Bioactive, Bioresorbable Forged Composites of Raw Particulate Unsintered Hydroxyapatite/Poly-L-Lactide Screws.

    Science.gov (United States)

    Kuroyanagi, Gen; Yoshihara, Hiroyuki; Yamamoto, Naohiro; Suzuki, Hiroyuki; Yamada, Kunio; Yoshida, Yukio; Otsuka, Takanobu; Takada, Naoya

    2018-05-01

    Forged composites of raw particulate unsintered hydroxyapatite/poly-L-lactide (F-u-HA/PLLA) devices possess high mechanical strength, bioactivity, and radio-opacity. The aim of this study was to assess the efficacy of F-u-HA/PLLA screws in the treatment of lateral tibial condylar fractures. From January 2005 to December 2010, a total of 7 patients with displaced closed lateral tibial condylar fractures (Schatzker type II) were treated using F-u-HA/PLLA screws. Open reduction and internal fixation was performed using 2 or 3 F-u-HA/PLLA screws. After surgery, weight bearing was not allowed for 6 weeks. Range of motion exercise was initiated after removal of the plaster splint. Radiographs were evaluated for fracture healing, joint depression, and the radioopacity of F-u-HA/PLLA screws. Clinical outcomes and postoperative complications were also assessed. Average follow-up was 44 months. All fractures were successfully healed. Average values for joint depression were 4.7 mm (range, 2-9 mm) preoperatively, 0.4 mm (range, 0-1 mm) postoperatively, and 0.4 mm (range, 0-1 mm) at final follow-up. Whole shadows of F-u-HA/PLLA screws were observed during the follow-up period. Breakage of screws, osteolysis, and a radiolucent zone around the screws were not observed at final follow-up. Average knee flexion and extension were 134° (range, 110° to 150°) and -1° (range, -10° to 0°), respectively. No patient had wound infection, late aseptic tissue response, or foreign body reaction postoperatively. None of the patients reported pain at final follow-up. These results suggest that F-u-HA/PLLA screws could be an alternative option for the treatment of lateral tibial condylar fractures. [Orthopedics. 2018; 41(3):e365-e368.]. Copyright 2018, SLACK Incorporated.

  10. Nanostructured hydroxyapatite powders produced by a flame-based technique

    Energy Technology Data Exchange (ETDEWEB)

    Trommer, R.M., E-mail: rafael_trommer@yahoo.com.br [Ceramic Materials Laboratory, av. Osvaldo Aranha 99/705, 90035190, Porto Alegre, RS (Brazil); Santos, L.A. [Biomaterials Laboratory, av. Bento Goncalves 9500, Campus do Vale Setor IV Predio 74 Sala 123, 91501970, Porto Alegre, RS (Brazil); Bergmann, C.P. [Ceramic Materials Laboratory, av. Osvaldo Aranha 99/705, 90035190, Porto Alegre, RS (Brazil)

    2009-08-01

    In this work we reported the production of hydroxyapatite (HA) powder, one of the most studied calcium phosphates in the bioceramics field, using a cost-effective apparatus, composed by three major components: the atomization device, the pilot and main flames and finally the powder collector system. Calcium acetate and ammonium phosphate, diluted in ethanol and water, were used as salts in the precursor solution. The Ca/P molar ratio in the precursor solution was 1.65, equivalent to biological hydroxyapatite. After its production and collection, HA powder was calcined at 600 deg. C for 2 h. X-ray diffraction analysis pointed to the formation of crystalline hydroxyapatite powders. Carbonate was identified in the powders by Fourier-transform infrared (FTIR) spectroscopy. Scanning electronic microscopy (SEM) showed that the powders were composed of spherical primary particles and secondary aggregates, with the morphology unchanged after calcination. By transmission electronic microscopy (TEM), it was observed that the crystallite size of the primary particles was 24.8 {+-} 5.8 nm, for the calcined powder. The specific surface area was 15.03 {+-} 6.4 and 26.50 {+-} 7.6 m{sup 2}/g, for the as-synthetized and calcined powder respectively.

  11. Management of localized advance loss of periodontal support associated Grade II furcation and intrabony defect in chronic periodontitis patient through amalgamation of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar Salaria

    2016-01-01

    Full Text Available Periodontal disease is infectious, complex, multifactorial, chronic inflammatory disease of supporting periodontal tissues that not only alters the bone morphology but also leads to the reduction in bone height. Different types of bony deformities such as horizontal, vertical, craters, and furcation result from periodontal disease, but vertical and Grade II furcation defects are more amenable to regenerative periodontal therapy. The present case report describes the current concept of periodontal diagnosis and the clinical radiographical efficiency of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules graft combination in the management of localized advance osseous defects with respect to tooth number 36 in chronic periodontitis patient at 1 year postoperatively.

  12. Management of localized advance loss of periodontal support associated Grade II furcation and intrabony defect in chronic periodontitis patient through amalgamation of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules.

    Science.gov (United States)

    Salaria, Sanjeev Kumar; Ghuman, Simrat Kaur; Kumar, Saurabh; Sharma, Garima

    2016-01-01

    Periodontal disease is infectious, complex, multifactorial, chronic inflammatory disease of supporting periodontal tissues that not only alters the bone morphology but also leads to the reduction in bone height. Different types of bony deformities such as horizontal, vertical, craters, and furcation result from periodontal disease, but vertical and Grade II furcation defects are more amenable to regenerative periodontal therapy. The present case report describes the current concept of periodontal diagnosis and the clinical radiographical efficiency of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules graft combination in the management of localized advance osseous defects with respect to tooth number 36 in chronic periodontitis patient at 1 year postoperatively.

  13. Hydroxyapatite-based porous aggregates: physico-chemical nature, structure, texture and architecture.

    Science.gov (United States)

    Fabbri, M; Celotti, G C; Ravaglioli, A

    1995-02-01

    At the request of medical teams from the maxillofacial sector, a highly porous ceramic support based on hydroxyapatite of around 70-80% porosity was produced with a pore size distribution similar to bone texture ( 150 microns, approximately 86 vol%). The ceramic substrates were conceived not only as a fillers for bone cavities, but also for use as drug dispensers and as supports to host cells to produce particular therapeutic agents. A method is suggested to obtain a substrate of high porosity, exploiting the impregnation of spongy substrate with hydroxyapatite ceramic particles. X-ray and scanning electron microscopy analyses were carried out to evaluate the nature of the new ceramic support in comparison with the most common commercial product; pore size distribution and porosity were controlled to known hydroxyapatite ceramic architecture for the different possible uses.

  14. Hybrid organic-inorganic materials based on hydroxyapatite structure

    Energy Technology Data Exchange (ETDEWEB)

    Moussa, Sana Ben; Bachouâ, Hassen [U.R. Matériaux et synthèse organique UR17ES31, Institut Préparatoire aux Etudes d’Ingénieur de Monastir, Université de Monastir, 5019 Monastir (Tunisia); Gruselle, Michel, E-mail: michel.gruselle@upmc.fr [Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, F-75005 Paris (France); Beaunier, Patricia [Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 7197, Laboratoire de Réactivité de Surface, F-75005 Paris (France); Flambard, Alexandrine [Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, F-75005 Paris (France); Badraoui, Béchir [U.R. Matériaux et synthèse organique UR17ES31, Institut Préparatoire aux Etudes d’Ingénieur de Monastir, Université de Monastir, 5019 Monastir (Tunisia)

    2017-04-15

    The present article details the formation of calcium hydroxyapatite synthesized by the hydrothermal way, in presence of glycine or sarcosine. The presence of these amino-acids during the synthetic processes reduces the crystalline growthing through the formation of hybrid organic-inorganic species The crystallite sizes are decreasing and the morphology is modified with the increase of the amino-acid concentration. - Graphical abstract: Formation of Ca carboxylate salt leading to the grafting of glycine and sarcosine on the Ca=Hap surface (R= H, CH3).

  15. Bioactive glass-based scaffolds for bone tissue engineering

    NARCIS (Netherlands)

    Will, J.; Gerhardt, L.C.; Boccaccini, A.R.

    2012-01-01

    Originally developed to fill and restore bone defects, bioactive glasses are currently also being intensively investigated for bone tissue engineering applications. In this chapter, we review and discuss current knowledge on porous bone tissue engineering scaffolds made from bioactive silicate

  16. Bioactive Glasses in Dentistry: A Review

    Directory of Open Access Journals (Sweden)

    Abbasi Z

    2015-03-01

    Full Text Available Bioactive glasses are silicate-based and can form a strong chemical bond with the tissues. These biomaterials are highly biocompatible and can form a hydroxyapatite layer when implanted in the body or soaked in the simulated body fluid. Due to several disadvantages, conventional glass processing method including melting of glass components, is replaced by sol-gel method with a large number of benefits such as low processing temperature, higher purity and homogeneity and therefore better control of bioactivity. Bioactive glasses have a wide range of applications, particularly in dentistry. These glasses can be used as particulates or monolithic shapes and porous or dense constructs in different applications such as remineralization or hypersensitivity treatment. Some properties of bioactive glasses such as antibacterial properties can be promoted by adding different elements into the glass. Bioactive glasses can also be used to modify different biocompatible materials that need to be bioactive. This study reviews the significant developments of bioactive glasses in clinical application, especially dentistry. Furthermore, we will discuss the field of bioactive glasses from beginning to the current developments, which includes processing methods, applications, and properties of these glasses.

  17. Nanocomposite bone scaffolds based on biodegradable polymers and hydroxyapatite.

    Science.gov (United States)

    Becker, Johannes; Lu, Lichun; Runge, M Brett; Zeng, Heng; Yaszemski, Michael J; Dadsetan, Mahrokh

    2015-08-01

    In tissue engineering, development of an osteoconductive construct that integrates with host tissue remains a challenge. In this work, the effect of bone-like minerals on maturation of pre-osteoblast cells was investigated using polymer-mineral scaffolds composed of poly(propylene fumarate)-co-poly(caprolactone) (PPF-co-PCL) and nano-sized hydroxyapatite (HA). The HA of varying concentrations was added to an injectable formulation of PPF-co-PCL and the change in thermal and mechanical properties of the scaffolds was evaluated. No change in onset of degradation temperature was observed due to the addition of HA, however compressive and tensile moduli of copolymer changed significantly when HA amounts were increased in composite formulation. The change in mechanical properties of copolymer was found to correlate well to HA concentration in the constructs. Electron microscopy revealed mineral nucleation and a change in surface morphology and the presence of calcium and phosphate on surfaces was confirmed using energy dispersive X-ray analysis. To characterize the effect of mineral on attachment and maturation of pre-osteoblasts, W20-17 cells were seeded on HA/copolymer composites. We demonstrated that cells attached more to the surface of HA containing copolymers and their proliferation rate was significantly increased. Thus, these findings suggest that HA/PPF-co-PCL composite scaffolds are capable of inducing maturation of pre-osteoblasts and have the potential for use as scaffold in bone tissue engineering. © 2014 Wiley Periodicals, Inc.

  18. Development of electrochemical folic acid sensor based on hydroxyapatite nanoparticles

    Science.gov (United States)

    Kanchana, P.; Sekar, C.

    2015-02-01

    We report the synthesis of hydroxyapatite (HA) nanoparticles (NPs) by a simple microwave irradiation method and its application as sensing element for the precise determination of folic acid (FA) by electrochemical method. The structure and composition of the HA NPs characterized using XRD, FTIR, Raman and XPS. SEM and EDX studies confirmed the formation of elongated spherical shaped HA NPs with an average particle size of about 34 nm. The HA NPs thin film on glassy carbon electrode (GCE) were deposited by drop casting method. Electrocatalytic behavior of FA in the physiological pH 7.0 was investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry. The fabricated HA/GCE exhibited a linear calibration plot over a wide FA concentration ranging from 1.0 × 10-7 to 3.5 × 10-4 M with the detection limit of 75 nM. In addition, the HA NPs modified GCE showed good selectivity toward the determination of FA even in the presence of a 100-fold excess of ascorbic acid (AA) and 1000-fold excess of other common interferents. The fabricated biosensor exhibits good sensitivity and stability, and was successfully applied for the determination of FA in pharmaceutical samples.

  19. A new injectable biphasic hydrogel based on partially hydrolyzed polyacrylamide and nano hydroxyapatite, crosslinked with chromium acetate, as scaffold for cartilage regeneration

    Science.gov (United States)

    Koushki, N.; Tavassoli, H.; Katbab, A. A.; Katbab, P.; Bonakdar, S.

    2015-05-01

    Polymer scaffolds are applied in the field of tissue engineering as three dimensional structures to organize cells and present stimuli to direct generation of a desired damaged tissue. In situ gelling scaffolds have attracted great attentions, as they are structurally similar to the extra cellular matrix (ECM). In the present work, attempts have been made to design and fabricate a new injectable and crosslinkable biphasic hydrogel based on partially hydrolyzed polyacrylamide (HPAM), chromium acetate as crosslink agent and nanocrystalline hydroxyapatite (nHAp) as reinforcing and bioactive agent for repair and regeneration of damaged cartilage. The distinct characteristic of HPAM is the presence of carboxylate anion groups on its backbone which allows to engineer the structure of the hydrogel for the desired bioactivity with appropriate cells differentiation towards both soft and hard (bone) tissues. The synthesized hydrogel exhibited bifunctional behavior which was derived by its biphasic structure in which one phase was loaded with nano hydroxyapatite to provide integration capability by subchondral bones and fix the hydrogel at cartilage defect without a need for suturing. The other phase differentiates the rabbit adipogenic mesenchymal stem cells (MSCs) towards soft tissue. Rheomechanical spectrometry (RMS) was employed to study the kinetic of the gelation including induction time and rate, as well as to measure the ultimate elastic modulus of the optimum crosslinked hydrogel. Surface tension measurement was also performed to tailor the surface characteristics of the gels. In vitro culturing of the cells inside the crosslinked hydrogel revealed high viability and high differentiation of the encapsulated rabbit stem cells, providing that the chromium acetate level was kept below 0.2 wt%. Based on the obtained results, the designed and fabricated biphasic hydrogel exhibited high potential as carrier for the stem cells for cartilage tissue engineering application

  20. The Correlation of Pore Size and Bioactivity of Spray-Pyrolyzed Mesoporous Bioactive Glasses

    Directory of Open Access Journals (Sweden)

    Yu-Jen Chou

    2017-05-01

    Full Text Available SiO2–CaO–P2O5-based mesoporous bioactive glasses (MBGs were synthesized by spray pyrolysis in this study. Three commonly used non-ionic tri-block copolymers (L121, P123, and F127 with various lengths of hydrophilic chains were applied as structural templates to achieve different pore sizes. A mesoporous structure was observed in each as-prepared specimen, and the results showed that the L121-treated MBG had the largest pore size. The results of bioactivity tests indicated that the growth of hydroxyapatite is related to the pore size of the materials.

  1. Abrasive wear of enamel by bioactive glass-based toothpastes.

    Science.gov (United States)

    Mahmood, Asad; Mneimne, Mohammed; Zou, Li Fong; Hill, Robert G; Gillam, David G

    2014-10-01

    To determine the abrasivity of a 45S5 bioactive glass based toothpaste on enamel as a function of the particle size and shape of the glass. 45S5 glass was synthesized ground and sieved to give various particle sized fractions toothpastes and their tooth brush abrasivity measured according to BS EN ISO11609 methodology. Enamel loss increased with increasing particle size. The percussion milled powder exhibited particles that had sharp edges and the pastes were significantly more abrasive than the pastes made with round ball milled powders. One interesting observation made during the present study was that there was preferential wear of the enamel at the dentin-enamel junction (DEJ), particularly with the coarse particle sized pastes.

  2. Whey Based Bioactive Peptides Used in Animal Products

    Directory of Open Access Journals (Sweden)

    Ayse Demet Karaman

    2016-10-01

    Full Text Available Bioactive peptides come out as a result of the hydrolysis of milk proteins and contain nutritional, functional and biological activities. Nowadays, the utilization of whey proteins to provide various features in the animal products such as meat and milk products and animal production has been increasing. In this compilation, after being introduced some general information about their common characteristics, bioactive peptides will be mentioned about their particularly recent usage in animal products.

  3. A New Highly Bioactive Composite for Scaffold Applications: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Antonella Sola

    2011-01-01

    Full Text Available Hydroxyapatite (HA has been widely investigated as scaffolding material for bone tissue engineering, mainly for its excellent biocompatibility. Presently, there is an increasing interest in the composites of hydroxyapatite with bioactive glasses, with the aim to obtain systems with improved bioactivity or mechanical properties. Moreover, modifying the ratio between bioactive glass and hydroxyapatite results in the possibility of controlling the reaction rate of the composite scaffold in the human body. However, high temperature treatments are usually required in order to sinter HA-based composites, causing the bioactive glass to crystallize into a glass-ceramic, with possible negative effects on its bioactivity. In the present research work, a glass composition belonging to the Na2O-CaO-P2O5-SiO2 system, with a reduced tendency to crystallize, is applied to realize HA-based composites. The novel samples can be sintered at a relative low temperature (750 °C compared to the widely studied HA/45S5 Bioglass® composites. This fact greatly helps to preserve the amorphous nature of the glass, with excellent effects in terms of bioactivity, according to in vitro tests. As a first application, the obtained composites are also tested to realize highly porous scaffolds by means of the standard burning out method.

  4. Investigating the effect of SiO2-TiO 2-CaO-Na 2O-ZnO bioactive glass doped hydroxyapatite: characterisation and structural evaluation.

    Science.gov (United States)

    Yatongchai, Chokchai; Wren, Anthony W; Curran, Declan J; Hampshire, Stuart; Towler, Mark R

    2014-07-01

    The effects of increasing bioactive glass additions, SiO2-TiO2-CaO-Na2O-ZnO up to 25 wt% in increments of 5 wt%, on the physical and mechanical properties of hydroxyapatite (HA) sintered at 900, 1000, 1100 and 1200 °C for 2 h was investigated. Increasing both the glass content and the temperature resulted in increased HA decomposition. This resulted in the formation of a number of bioactive phases. However the presence of the liquidus glass phase did not result in increased densification levels. At 1000 and 1100 °C the additions of 5 wt% glass resulted in a decrease in density which never recovered with increasing glass content. At 1200 °C a cyclic pattern resulted from increasing glass content. There was no direct relationship between strength and density with all samples experiencing no change or a decrease in strength with increasing glass content. Weibull statistics displayed no pattern with increasing glass content.

  5. Characterization of new bioactive coatings of hydroxyapatite and TiO{sub 2} obtained by High-Velocity Oxy-Fuel; Caracterizacion de nuevos recubrimientos biocompatibles de hidroxiapatita-TiO{sub 2} obtenidos mediante Proyeccion Termica de Alta Velocidad

    Energy Technology Data Exchange (ETDEWEB)

    Melero, H.; Fernandez, J.; Dosta, S.; Guilemany, J. M.

    2011-07-01

    Hydroxyapatite (Hap: Ca{sub 1}0(PO{sub 4}){sub 6}OH{sub 2}) is a biocompatible and bioactive ceramic material widely used as a coating on metal surfaces (dental implants, hip replacements ...), but the low adhesion between Hap and the substrate, due to differences in thermal expansion coefficients of both (very important in thermal spraying because of the fast cooling of the coating, which can produce a lost of adherence), and the degradation of Hap, have been tried to be improved through the incorporation of TiO{sub 2} to get a good combination of mechanical properties. Therefore, the objective of this project is to produce coatings of Hap 80% TiO{sub 2} and 20% (by weight) on Ti6Al4V by High-Speed Thermal Spray (HVOF). The study of the microstructure has been carried out using scanning electron microscopy and characterization of the crystalline phases by X-ray diffraction and Raman spectrometry. The coatings adhesion has been measured by tensile tests according to ASTM C633-01 (2008), and their bioactivity also has been evaluated through its immersion in simulated body fluid (SBF), in order to measure their capacity to form an apatite layer on their surface. (Author) 26 refs.

  6. Cellular compatibility of nanocomposite scaffolds based on hydroxyapatite entrapped in cellulose network for bone repair

    Energy Technology Data Exchange (ETDEWEB)

    Beladi, Faranak [Material and Biomaterial Research Center, Tehran (Iran, Islamic Republic of); Saber-Samandari, Samaneh, E-mail: samaneh.saber@gmail.com [Department of Chemistry, Eastern Mediterranean University, Gazimagusa, TRNC via Mersin 10 (Turkey); Saber-Samandari, Saeed, E-mail: saeedss@aut.ac.ir [New Technologies Research Center, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2017-06-01

    In the past few decades, artificial graft materials for bone tissue engineering have gained much importance. In this study, novel porous 3D nanocomposite scaffolds composed of polyacrylamide grafted cellulose and hydroxyapatite were proposed. They were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD). The swelling behavior of the scaffolds was examined in both water and phosphate buffer saline (PBS) solution. The cytotoxicity of the scaffolds was determined by MTT assays on human fibroblast gum (HuGu) cells. Results showed that the nanocomposite scaffolds were highly porous with maximum porosity of 85.7% interconnected with a pore size of around 72–125 μm. The results of cell culture experiments showed that the scaffolds extracts do not have cytotoxicity in any concentration. Obtained results suggested that the introduced scaffolds are comparable with the trabecular bone from the compositional, structural, and mechanical perspectives and have a great potential as a bone substitute. - Highlights: • A series of biocompatible scaffolds were synthesized through a novel multi-step route. • The porosity increased by increasing n-HAp amounts in the structure of the scaffold. • The mechanical properties of the scaffolds were found close to those of trabecular bone. • The results suggest that the scaffold extracts do not have any cell cytotoxicity. • The scaffold can be efficient as a bioactive bone implant for tissue engineering.

  7. Cellular compatibility of nanocomposite scaffolds based on hydroxyapatite entrapped in cellulose network for bone repair

    International Nuclear Information System (INIS)

    Beladi, Faranak; Saber-Samandari, Samaneh; Saber-Samandari, Saeed

    2017-01-01

    In the past few decades, artificial graft materials for bone tissue engineering have gained much importance. In this study, novel porous 3D nanocomposite scaffolds composed of polyacrylamide grafted cellulose and hydroxyapatite were proposed. They were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD). The swelling behavior of the scaffolds was examined in both water and phosphate buffer saline (PBS) solution. The cytotoxicity of the scaffolds was determined by MTT assays on human fibroblast gum (HuGu) cells. Results showed that the nanocomposite scaffolds were highly porous with maximum porosity of 85.7% interconnected with a pore size of around 72–125 μm. The results of cell culture experiments showed that the scaffolds extracts do not have cytotoxicity in any concentration. Obtained results suggested that the introduced scaffolds are comparable with the trabecular bone from the compositional, structural, and mechanical perspectives and have a great potential as a bone substitute. - Highlights: • A series of biocompatible scaffolds were synthesized through a novel multi-step route. • The porosity increased by increasing n-HAp amounts in the structure of the scaffold. • The mechanical properties of the scaffolds were found close to those of trabecular bone. • The results suggest that the scaffold extracts do not have any cell cytotoxicity. • The scaffold can be efficient as a bioactive bone implant for tissue engineering.

  8. Use of agroindustrial waste in the preparation of nanocomposites based on bacterial cellulose and hydroxyapatite

    International Nuclear Information System (INIS)

    Duarte, Eden B.; Chagas, Bruna S. das; Feitosa, Judith P.A.; Andrade, Fabia K.; Borges, Maria F.; Muniz, Celli R.; Souza Filho, Men de Sa M.; Rosa, Morsyleide F.; Brigida, Ana I.; Morais, Joao P.S.

    2015-01-01

    Environmental issues have supported the interest in renewable sources and agroindustrial residues became a significant resource for the production of new materials. The present work presents the use of agroindustrial residues to obtain bacterial cellulose (BC) for further elaboration of nanocomposites with hydroxyapatite (HA). The production of BC membranes occurred in Hestrin & Schramm medium, cashew juice and sisal liquid waste cultivated under static conditions. After the incubation period, the BC membranes were purified and nanocomposites prepared by successive immersion of the purified membranes in solutions of Calcium Chloride (CaCl_2), and Sodium Phosphate (Na_2HPO_4), followed by drying and subsequent characterization. The materials obtained were characterized by Thermogravimetric Analysis (TGA) and X-ray Diffraction (XRD). Additionally, in vitro tests were performed for nanocomposites. The results showed the production of cellulose from the three substrates studied, without the need for further supplementation or pH change. In all characterizations, structure and typical behavior of bacterial cellulose were found. The composites showed bioactivity and the adsorption capacity of proteins, which lead to potential biocompatibility of these materials. (author)

  9. Hydroxyapatite-TiO(2)-based nanocomposites synthesized in supercritical CO(2) for bone tissue engineering: physical and mechanical properties.

    Science.gov (United States)

    Salarian, Mehrnaz; Xu, William Z; Wang, Zhiqiang; Sham, Tsun-Kong; Charpentier, Paul A

    2014-10-08

    Calcium phosphate-based nanocomposites offer a unique solution toward producing scaffolds for orthopedic and dental implants. However, despite attractive bioactivity and biocompatibility, hydroxyapatite (HAp) has been limited in heavy load-bearing applications due to its intrinsically low mechanical strength. In this work, to improve the mechanical properties of HAp, we grew HAp nanoplates from the surface of one-dimensional titania nanorod structures by combining a coprecipitation and sol-gel methodology using supercritical fluid processing with carbon dioxide (scCO2). The effects of metal alkoxide concentration (1.1-1.5 mol/L), reaction temperature (60-80 °C), and pressure (6000-8000 psi) on the morphology, crystallinity, and surface area of the resulting nanostructured composites were examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and Brunauer-Emmet-Teller (BET) method. Chemical composition of the products was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray absorption near-edge structure (XANES) analyses. HAp nanoplates and HAp-TiO2 nanocomposites were homogeneously mixed within poly(ε-caprolactone) (PCL) to develop scaffolds with enhanced physical and mechanical properties for bone regeneration. Mechanical behavior analysis demonstrated that the Young's and flexural moduli of the PCL/HAp-TiO2 composites were substantially higher than the PCL/HAp composites. Therefore, this new synthesis methodology in scCO2 holds promise for bone tissue engineering with improved mechanical properties.

  10. Evaluation of bioactivity in vitro of endodontic calcium aluminate cement; Avaliacao da bioatividade in vitro de cimento endodontico a base de aluminato de calcio

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, I.R.; Andrade, T.L.; Santos, G.L., E-mail: ivonero@univap.br [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil); Pandolfelli, V.C. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil)

    2011-07-01

    Bioactivity is referred to as the capacity of a material to develop a stable bond with living tissue via the deposition of hydroxyapatite. Materials which exhibit this property can be used to repair diseased or damaged bone tissue and can be designed to remain in situ indefinitely. An indication of bioactivity can be obtained by the formation of a hydroxyapatite layer on the surface of a substrate in simulated body fluids (SBF) in vitro. Therefore, set samples of calcium aluminate endodontic cement were maintained in contact with SBF solutions (Kokubo and Rigo) and their surfaces were later evaluated by means of SEM, EDX and DRX. Measurements of pH and ionic conductivity were also carried out for SBF solutions in contact with set samples of endodontic cement. The ideal conditions of precipitation were obtained in SBF Rigo been observed a surface layer with spherical morphology characteristic of stoichiometric hydroxyapatite.(author)

  11. Bioactive glasses potential biomaterials for future therapy

    CERN Document Server

    Kaur, Gurbinder

    2017-01-01

    This book describes the history, origin and basic characteristics of bioactive materials. It includes a chapter dedicated to hydroxyapatite mineral, its formation and its bioactive properties. The authors address how cytotoxicity is a determining step for bioactivity. Applications of bioactive materials in the contexts of tissue regeneration, bone regeneration and cancer therapy are also covered. Silicate, metallic and mesoporous glasses are described, as well as the challenges and future prospects of research in this field.

  12. Manipulation of partially oriented hydroxyapatite building blocks to form flowerlike bundles without acid-base regulation.

    Science.gov (United States)

    Wen, Zhenliang; Wang, Zihao; Chen, Jingdi; Zhong, Shengnan; Hu, Yimin; Wang, Jianhua; Zhang, Qiqing

    2016-06-01

    The application of hydroxyapatite (HAP) in different fields depends greatly on its morphology, composition and structure. Besides, the main inorganic building blocks of human bones and teeth are also HAP. Therefore, accurate shape and aggregation control and of hydroxyapatite particles will be of great interest. Herein, oriented bundles of flowerlike HAP nanorods were successfully prepared through hydrothermal treatment without acid-base regulation, with the mono-alkyl phosphate (MAP) and sodium citrate as surfactant and chelating agent, respectively. The prepared samples were characterized by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and zeta potential, the pH value and conductivity value of suspension were characterized by pH meter and conductivity measurement. The results showed that the MAP and citrate play an important role in assembly of HAP nanorods without acid-base regulation. Citrate calcium complex could decompose slowly and release citrate ions at hydrothermal conditions. Besides, the further decomposition of citrate ions could release aconitic acid as the reaction time prolongs. Moreover, the possible scheme for the formation process was discussed in detail. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Mechanochemically synthesized kalsilite based bioactive glass-ceramic composite for dental vaneering

    Science.gov (United States)

    Kumar, Pattem Hemanth; Singh, Vinay Kumar; Kumar, Pradeep

    2017-08-01

    Kalsilite glass-ceramic composites have been prepared by a mechanochemical synthesis process for dental veneering application. The aim of the present study is to prepare bioactive kalsilite composite material for application in tissue attachment and sealing of the marginal gap between fixed prosthesis and tooth. Mechanochemical synthesis is used for the preparation of microfine kalsilite glass-ceramic. Low temperature frit and bioglass have been prepared using the traditional quench method. Thermal, microstructural and bioactive properties of the composite material have been examined. The feasibility of the kalsilite to be coated on the base commercial opaque as well as the bioactive behavior of the coated specimen has been confirmed. This study indicates that the prepared kalsilite-based composites show similar structural, morphological and bioactive behavior to that of commercial VITA VMK95 Dentin 1M2.

  14. Zirconia/Hydroxyapatite Composites Synthesized Via Sol-Gel: Influence of Hydroxyapatite Content and Heating on Their Biological Properties

    Science.gov (United States)

    Bollino, Flavia; Armenia, Emilia; Tranquillo, Elisabetta

    2017-01-01

    Zirconia (ZrO2) and zirconia-based glasses and ceramics are materials proposed for use in the dental and orthopedic fields. In this work, ZrO2 glass was modified by adding different amounts of bioactive and biocompatible hydroxyapatite (HAp). ZrO2/HAp composites were synthesized via the sol-gel method and heated to different temperatures to induce modifications of their chemical structure, as ascertained by Fourier transform infrared spectroscopy (FTIR) analysis. The aim was to investigate the effect of both HAp content and heating on the biological performances of ZrO2. The materials’ bioactivity was studied by soaking samples in a simulated body fluid (SBF). FTIR and scanning electron microscopy (SEM)) analyses carried out after exposure to SBF showed that all materials are bioactive, i.e., they are able to form a hydroxyapatite layer on their surface. Moreover, the samples were soaked in a solution containing bovine serum albumin (BSA). FTIR analysis proved that the synthesized materials are able to adsorb the blood protein, the first step of cell adhesion. WST-8 ([2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt]) assay showed that no cytotoxicity effects were induced by the materials’ extract. However, the results proved that bioactivity increases with both the HAp content and the temperature used for the thermal treatment, whereas biocompatibility increases with heating but is not affected by the HAp content. PMID:28773116

  15. Development of novel strontium containing bioactive glass based calcium phosphate cement.

    Science.gov (United States)

    D'Onofrio, A; Kent, N W; Shahdad, S A; Hill, R G

    2016-06-01

    The aim of this study was to investigate the effect on properties of increasing strontium substitution for calcium in bioactive glasses used as precursors for novel calcium phosphate cements. Glasses were produced by progressively substituting strontium for calcium. Cements were prepared by mixing the glass powder with Ca(H2PO4)2 powder with a 2.5% solution of Na2HPO4. Setting times and compressive strength were measured after 1h, 1 day, 7 days and 28 days immersion in Tris buffer solution. X-ray diffraction (XRD), Fourier transform infrared spectroscopy and radiopacity were measured and crystal morphology was assessed using scanning electron microscopy. A correlation between the phases formed, morphology of the crystallites, setting time and compressive strength were analyzed. Setting time increased proportionally with strontium substitution in the glass up to 25%, whereas for higher substitutions it decreased. Compressive strength showed a maximum value of 12.5MPa and was strongly influenced by the interlocking of the crystals and their morphology. XRD showed that the presence of strontium influenced the crystal phases formed. Octacalcium phosphate (Ca8H2(PO4)6·5H2O, OCP) was the main phase present after 1h and 1 day whereas after 28 days OCP was completely transformed to strontium-containing hydroxyapatite (SrxCa(10-x)(PO4)6(OH)2, SrHA). Radiopacity increased proportionally to strontium substitution in the glass. A novel method to develop a bone substitute forming in vitro SrHA as a final product by using a bioactive glass as a precursor was shown. These novel injectable bioactive glass cements are promising materials for dental and orthopedic applications. Further in vivo characterizations are being conducted. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. ITPI: Initial Transcription Process-Based Identification Method of Bioactive Components in Traditional Chinese Medicine Formula

    Directory of Open Access Journals (Sweden)

    Baixia Zhang

    2016-01-01

    Full Text Available Identification of bioactive components is an important area of research in traditional Chinese medicine (TCM formula. The reported identification methods only consider the interaction between the components and the target proteins, which is not sufficient to explain the influence of TCM on the gene expression. Here, we propose the Initial Transcription Process-based Identification (ITPI method for the discovery of bioactive components that influence transcription factors (TFs. In this method, genome-wide chip detection technology was used to identify differentially expressed genes (DEGs. The TFs of DEGs were derived from GeneCards. The components influencing the TFs were derived from STITCH. The bioactive components in the formula were identified by evaluating the molecular similarity between the components in formula and the components that influence the TF of DEGs. Using the formula of Tian-Zhu-San (TZS as an example, the reliability and limitation of ITPI were examined and 16 bioactive components that influence TFs were identified.

  17. Mechanical and thermal properties of hydroxyapatite filled poly(methyl methacrylate) heat processed denture base material

    International Nuclear Information System (INIS)

    Mohamed, S.H.; Arifin, A.; Mohd Ishak, Z.A.; Nizam, A.; Samsudin, A.R.

    2004-01-01

    The aim of this study was to evaluate the effect of powder-to-liquid ratio on the glass transition temperature (Tg) and the tensile properties of denture base material prepared from poly (methyl methacrylate) (PMMA) and hydroxyapatite (HA) previously treated with 3-trimethoxysilylpropyl methacrylate (γ-MPS). Specimens for, mechanical testing were prepared by adding composites powder (PMMA, BPO and RA) to the monomer (MMA and EGDMA) followed by hand mixing as in dental laboratory description usage. The glass transition temperature was studied by using differential scanning calorimetry (DSQ. It was observed that the tensile properties and the Tg were affected by the powder-to-liquid ratio. The mechanical characterization of the materials were performed by using single edge notch-tension (SEN-T) specimens; the fracture toughness was slightly higher in formulation which contained RA filler compared to commercial denture base material. (Author)

  18. Accelerator based synthesis of hydroxyapatite by MeV ion implantation

    International Nuclear Information System (INIS)

    Rautray, Tapash R.; Narayanan, R.; Kwon, Tae-Yub; Kim, Kyo-Han

    2010-01-01

    Accelerator based MeV ion implantation of Ca 2+ and P 2+ into the titanium substrate to form hydroxyapatite (HA) has been carried out. Calcium hydroxide was formed after heating the calcium implanted titanium in air at 80 o C for 3 h. Upon subsequent annealing for 5 min at 600 o C HA was formed on the surface. Penetration depth of the HA layer in this method is much higher as compared to keV ion implantation. By elemental analysis, Ca/P ratio of the HA was found to be 1.76 which is higher than the ideal 1.67. This higher Ca/P ratio is attributed to the higher penetration depth of the MeV technique used.

  19. Polymer-Ceramic Composite Scaffolds: The Effect of Hydroxyapatite and β-tri-Calcium Phosphate

    OpenAIRE

    Boyang Huang; Guilherme Caetano; Cian Vyas; Jonny James Blaker; Carl Diver; Paulo Bártolo

    2018-01-01

    The design of bioactive scaffolds with improved mechanical and biological properties is an important topic of research. This paper investigates the use of polymer-ceramic composite scaffolds for bone tissue engineering. Different ceramic materials (hydroxyapatite (HA) and β-tri-calcium phosphate (TCP)) were mixed with poly-ε-caprolactone (PCL). Scaffolds with different material compositions were produced using an extrusion-based additive manufacturing system. The produced scaffolds were physi...

  20. Understanding the structural drivers governing glass-water interactions in borosilicate based model bioactive glasses.

    Science.gov (United States)

    Stone-Weiss, Nicholas; Pierce, Eric M; Youngman, Randall E; Gulbiten, Ozgur; Smith, Nicholas J; Du, Jincheng; Goel, Ashutosh

    2018-01-01

    The past decade has witnessed a significant upsurge in the development of borate and borosilicate based resorbable bioactive glasses owing to their faster degradation rate in comparison to their silicate counterparts. However, due to our lack of understanding about the fundamental science governing the aqueous corrosion of these glasses, most of the borate/borosilicate based bioactive glasses reported in the literature have been designed by "trial-and-error" approach. With an ever-increasing demand for their application in treating a broad spectrum of non-skeletal health problems, it is becoming increasingly difficult to design advanced glass formulations using the same conventional approach. Therefore, a paradigm shift from the "trial-and-error" approach to "materials-by-design" approach is required to develop new-generations of bioactive glasses with controlled release of functional ions tailored for specific patients and disease states, whereby material functions and properties can be predicted from first principles. Realizing this goal, however, requires a thorough understanding of the complex sequence of reactions that control the dissolution kinetics of bioactive glasses and the structural drivers that govern them. While there is a considerable amount of literature published on chemical dissolution behavior and apatite-forming ability of potentially bioactive glasses, the majority of this literature has been produced on silicate glass chemistries using different experimental and measurement protocols. It follows that inter-comparison of different datasets reveals inconsistencies between experimental groups. There are also some major experimental challenges or choices that need to be carefully navigated to unearth the mechanisms governing the chemical degradation behavior and kinetics of boron-containing bioactive glasses, and to accurately determine the composition-structure-property relationships. In order to address these challenges, a simplified

  1. In vitro bioactivity and antimicrobial tuning of bioactive glass nanoparticles added with neem (Azadirachta indica) leaf powder.

    Science.gov (United States)

    Prabhu, M; Ruby Priscilla, S; Kavitha, K; Manivasakan, P; Rajendran, V; Kulandaivelu, P

    2014-01-01

    Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications.

  2. In Vitro Bioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder

    Science.gov (United States)

    Prabhu, M.; Ruby Priscilla, S.; Kavitha, K.; Manivasakan, P.; Rajendran, V.; Kulandaivelu, P.

    2014-01-01

    Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications. PMID:25276834

  3. In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants.

    Science.gov (United States)

    Sutha, S; Kavitha, K; Karunakaran, G; Rajendran, V

    2013-10-01

    A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58-1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Three-dimensional bioactive glass implants fabricated by rapid prototyping based on CO(2) laser cladding.

    Science.gov (United States)

    Comesaña, R; Lusquiños, F; Del Val, J; López-Álvarez, M; Quintero, F; Riveiro, A; Boutinguiza, M; de Carlos, A; Jones, J R; Hill, R G; Pou, J

    2011-09-01

    Three-dimensional bioactive glass implants were produced by rapid prototyping based on laser cladding without using moulds. CO(2) laser radiation was employed to melt 45S5 and S520 bioactive glass particles and to deposit the material layer by layer following a desired geometry. Controlled thermal input and cooling rate by fine tuning of the processing parameters allowed the production of crack-free fully dense implants. Microstructural characterization revealed chemical composition stability, but crystallization during processing was extensive when 45S5 bioactive glass was used. Improved results were obtained using the S520 bioactive glass, which showed limited surface crystallization due to an expanded sintering window (the difference between the glass transition temperature and crystallization onset temperature). Ion release from the S520 implants in Tris buffer was similar to that of amorphous 45S5 bioactive glass prepared by casting in graphite moulds. Laser processed S520 scaffolds were not cytotoxic in vitro when osteoblast-like MC3T3-E1 cells were cultured with the dissolution products of the glasses; and the MC3T3-E1 cells attached and spread well when cultured on the surface of the materials. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. In situ annealing of hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Johnson, Shevon; Haluska, Michael; Narayan, Roger J.; Snyder, Robert L.

    2006-01-01

    Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Unfortunately, problems with adhesion, poor mechanical integrity, and incomplete bone ingrowth limit the use of many conventional hydroxyapatite surfaces. In this work, we have developed a novel technique to produce crystalline hydroxyapatite thin films involving pulsed laser deposition and postdeposition annealing. Hydroxyapatite films were deposited on Ti-6Al-4V alloy and Si (100) using pulsed laser deposition, and annealed within a high temperature X-ray diffraction system. The transformation from amorphous to crystalline hydroxyapatite was observed at 340 deg. C. Mechanical and adhesive properties were examined using nanoindentation and scratch adhesion testing, respectively. Nanohardness and Young's modulus values of 3.48 and 91.24 GPa were realized in unannealed hydroxyapatite films. Unannealed and 350 deg. C annealed hydroxyapatite films exhibited excellent adhesion to Ti-6Al-4V alloy substrates. We anticipate that the adhesion and biological properties of crystalline hydroxyapatite thin films may be enhanced by further consideration of deposition and annealing parameters

  6. In Vitro Evaluation of Nanoscale Hydroxyapatite-Based Bone Reconstructive Materials with Antimicrobial Properties.

    Science.gov (United States)

    Ajduković, Zorica R; Mihajilov-Krstev, Tatjana M; Ignjatović, Nenad L; Stojanović, Zoran; Mladenović-Antić, Snezana B; Kocić, Branislava D; Najman, Stevo; Petrović, Nenad D; Uskoković, Dragan P

    2016-02-01

    In the field of oral implantology the loss of bone tissue prevents adequate patient care, and calls for the use of synthetic biomaterials with properties that resemble natural bone. Special attention is paid to the risk of infection after the implantation of these materials. Studies have suggested that some nanocontructs containing metal ions have antimicrobial properties. The aim of this study was to examine the antimicrobial and hemolytic activity of cobalt-substituted hydroxyapatite nanoparticles, compared to hydroxyapatite and hydroxyapatite/poly-lactide-co-glycolide. The antibacterial effects of these powders were tested against two pathogenic bacterial strains: Escherichia coi (ATCC 25922) and Staphylococcus aureus (ATCC 25923), using the disc diffusion method and the quantitative antimicrobial test in a liquid medium. The quantitative antimicrobial test showed that all of the tested biomaterials have some antibacterial properties. The effects of both tests were more prominent in case of S. aureus than in E coli. A higher percentage of cobalt in the crystal structure of cobalt-substituted hydroxyapatite nanoparticles led to an increased antimicrobial activity. All of the presented biomaterial samples were found to be non-hemolytic. Having in mind that the tested of cobalt-substituted hydroxyapatite (Ca/Co-HAp) material in given concentrations shows good hemocompatibility and antimicrobial effects, along with its previously studied biological properties, the conclusion can be reached that it is a potential candidate that could substitute calcium hydroxyapatite as the material of choice for use in bone tissue engineering and clinical practices in orthopedic, oral and maxillofacial surgery.

  7. Characterization of dicalcium phosphate dihydrate cements prepared using a novel hydroxyapatite-based formulation

    International Nuclear Information System (INIS)

    Alge, Daniel L; Cruz, Grace Santa; Chu, Tien-Min Gabriel; Goebel, W Scott

    2009-01-01

    Dicalcium phosphate dihydrate (DCPD) cements are typically prepared using β-tricalcium phosphate (β-TCP) as the base component. However, hydroxyapatite (HA) is an interesting alternative because of its potential for reducing cement acidity, as well as modulating cement properties via ionic substitutions. In the present study, we have characterized DCPD cements prepared with a novel formulation based on monocalcium phosphate monohydrate (MCPM) and HA. Cements were prepared using a 4:1 MCPM:HA molar ratio. The reactivity of HA in this system was verified by showing DCPD formation using poorly crystalline HA, as well as highly crystalline HA. Evaluation of cements prepared with poorly crystalline HA revealed that setting occurs rapidly in the MCPM/HA system, and that the use of a setting regulator is necessary to maintain workability of the cement paste. Compressive testing showed that MCPM/HA cements have strengths comparable to what has previously been published for DCPD cements. However, preliminary in vitro analysis of cement degradation revealed that conversion of DCPD to HA may occur much more rapidly in the MCPM/HA system compared to cements prepared with β-TCP. Future studies should investigate this property further, as it could have important implications for the use of HA-based DCPD cement formulations.

  8. Micro-tribological properties of hydroxyapatite-based composites in dry sliding

    International Nuclear Information System (INIS)

    Lu, Zhi; Liu, Yong; Liu, Bowei; Liu, Meiling

    2013-01-01

    Highlights: ► The micro-tribological properties of HA-based composites were investigated. ► The micro-scale test is greatly benefits to the analyses of the wear mechanism. ► A higher speed benefits the formation of the lubricating layer, when high in Cu. ► With increasing Cu, the wear mechanism shift from abrasive wear to adhesive wear. - Abstract: The micro-tribological properties of hydroxyapatite-based composites sliding against alumina balls were investigated by a ball-on-block tribometer. Surface properties of the HA-based composites were measured and examined by using atomic force microscopy and scanning electron microscopy. Running-in behavior during sliding tests was studied as a function of surface properties. The effects of copper fibers, initial surface roughness, and sliding velocity on the friction coefficient and the wear resistance were discussed. Results show that a lubricant layer benefits the tribological properties of the composites. With the increasing of Cu, the lubricant layer is more stable, and resistant to increase of the sliding velocity. At a Cu content of 15%, the wear curve is very stable even at a velocity of 900 rpm. The wear mechanism also changes from abrasive wear to adhesive wear. A model was quoted to describe the relationship between the wear resistant and the load

  9. Characterization and formation of hydroxyapatite on Ti6Al4V coated by plasma electrolytic oxidation

    International Nuclear Information System (INIS)

    Durdu, Salih; Deniz, Ömer Faruk; Kutbay, Işıl; Usta, Metin

    2013-01-01

    Highlights: ► Ti6Al4V alloys were coated by PEO in calcium acetate and β-calcium glycerophosphate. ► Hydroxyapatite and calcium apatite based phases were directly formed on Ti6Al4V. ► Hydroxyapatite coatings were characterized systematically for different times. ► After 5 min, hydroxyapatite and calcium based phases begin to form on the coating. ► HAp on the coating is amorphous due to the rapid solidification during PEO. - Abstract: In this study, Ti6Al4V alloy was coated in the solution consisting of calcium acetate (CA) and β-calcium glycerophosphate (β-Ca-GP) by plasma electrolytic oxidation (PEO) to produce hydroxyapatite and calcium apatite-based composite used as of bioactive and biocompatible materials in biomedical applications. The phase structures, surface morphologies, functional groups of molecules, chemical compositions of the surfaces and the binding energies of atoms in the coating were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. Anatase, rutile, calcium oxide, titanium phosphide, whitlockite, tri-calcium phosphate (TCP), perovskite calcium titanate and hydroxyapatite phases on the coating were detected by XRD analysis. The surface of coatings produced by PEO method has a porous structure. The amount of amorphous hydroxyapatite is the highest value for the coating produced at 5 min in XPS and ATR-FTIR results, whereas the amount of crystalline hydroxyapatite has the highest value for coating produced at 120 min in XRD results.

  10. Drug and bioactive molecule screening based on a bioelectrical impedance cell culture platform

    Directory of Open Access Journals (Sweden)

    Ramasamy S

    2014-12-01

    Full Text Available Sakthivel Ramasamy,1 Devasier Bennet,1 Sanghyo Kim1,2 1Department of Bionanotechnology, Gachon University, Gyeonggi-Do, Republic of Korea; 2Graduate Gachon Medical Research Institute, Gil Medical Center, Incheon, Republic of Korea Abstract: This review will present a brief discussion on the recent advancements of bioelectrical impedance cell-based biosensors, especially the electric cell-substrate impedance sensing (ECIS system for screening of various bioactive molecules. The different technical integrations of various chip types, working principles, measurement systems, and applications for drug targeting of molecules in cells are highlighted in this paper. Screening of bioactive molecules based on electric cell-substrate impedance sensing is a trial-and-error process toward the development of therapeutically active agents for drug discovery and therapeutics. In general, bioactive molecule screening can be used to identify active molecular targets for various diseases and toxicity at the cellular level with nanoscale resolution. In the innovation and screening of new drugs or bioactive molecules, the activeness, the efficacy of the compound, and safety in biological systems are the main concerns on which determination of drug candidates is based. Further, drug discovery and screening of compounds are often performed in cell-based test systems in order to reduce costs and save time. Moreover, this system can provide more relevant results in in vivo studies, as well as high-throughput drug screening for various diseases during the early stages of drug discovery. Recently, MEMS technologies and integration with image detection techniques have been employed successfully. These new technologies and their possible ongoing transformations are addressed. Select reports are outlined, and not all the work that has been performed in the field of drug screening and development is covered. Keywords: screening of bioactive agents, impedance-based cell

  11. A novel tyrosinase biosensor based on hydroxyapatite-chitosan nanocomposite for the detection of phenolic compounds

    International Nuclear Information System (INIS)

    Lu Limin; Zhang Li; Zhang Xiaobing; Huan Shuangyan; Shen Guoli; Yu Ruqin

    2010-01-01

    A novel tyrosinase biosensor based on hydroxyapatite nanoparticles (nano-HA)-chitosan nanocomposite has been developed for the detection of phenolic compounds. The uniform and size controlled nano-HA was synthesized by hydrothermal method, and its morphological characterization was examined by transmission electron microscope (TEM). Tyrosinase was then immobilized on a nano-HA-chitosan nanocomposite-modified gold electrode. Electrochemical impedance spectroscopy and cyclic voltammetry were used to characterize the sensing film. The prepared biosensor was applied to determine phenolic compounds by monitoring the reduction signal of the biocatalytically produced quinone species at -0.2 V (vs. saturated calomel electrode). The effects of the pH, temperature and applied potential on the biosensor performance were investigated, and experimental conditions were optimized. The biosensor exhibited a linear response to catechol over a wide concentration range from 10 nM to 7 μM, with a high sensitivity of 2.11 x 10 3 μA mM -1 cm -2 , and a limit of detection down to 5 nM (based on S/N = 3). The apparent Michaelis-Menten constants of the enzyme electrode were estimated to be 3.16, 1.31 and 3.52 μM for catechol, phenol and m-cresol, respectively. Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.

  12. Coupling of HDPE/hydroxyapatite composites by silane-based methodologies.

    Science.gov (United States)

    Sousa, R A; Reis, R L; Cunha, A M; Bevis, M J

    2003-06-01

    Several coupling treatments based on silane chemicals were investigated for the development of high density (HDPE)/hydroxyapatite (HA) composites. Two HA powders, sintered HA (HAs) and non sintered HA (HAns), were studied in combination with five silanes, namely y-methacryloxy propyltrimethoxy silane (MEMO), 3-(2-aminoethyl)aminopropyltrimethoxy silane (DAMO), vinyltrimethoxy silane (VTMO), 3-aminopropyltriethoxy silane (AMEO) and trimethoxypropyl silane (PTMO). The HA particles were treated by a dipping in method or by spraying with silane solutions. After drying, the treated powders were compounded with HDPE or HDPE with acrylic acid and/or organic peroxide and subsequently compression molded. The tensile test specimens obtained from the molded plates were tensile tested and their fracture surfaces were observed by scanning electron microscopy (SEM). For the sintered HA (HAs) composites, the most effective coupling treatments concerning stiffness are those based on MEMO and AMEO. The low influence of these coupling procedures on strength is believed to be associated to the low volume fraction and the relatively smooth surface of the used HA particles. For the non-sintered HA (HAns) composites, it was possible to improve significantly both the stiffness and the strength. Amino silanes demonstrated to be highly efficient concerning strength enhancement. The higher effectiveness of the coupling treatments for HAns filled composites is attributed to their higher particle surface area, smaller particle size distribution and expected higher chemical reactivity. For both cases, the improvement in mechanical performance after the coupling treatment is consistent with the enhancement in interfacial adhesion observed by SEM.

  13. Study of the mechanical stability and bioactivity of Bioglass(®) based glass-ceramic scaffolds produced via powder metallurgy-inspired technology.

    Science.gov (United States)

    Boccardi, Elena; Melli, Virginia; Catignoli, Gabriele; Altomare, Lina; Jahromi, Maryam Tavafoghi; Cerruti, Marta; Lefebvre, Louis-Philippe; De Nardo, Luigi

    2016-02-02

    Large bone defects are challenging to heal, and often require an osteoconductive and stable support to help the repair of damaged tissue. Bioglass-based scaffolds are particularly promising for this purpose due to their ability to stimulate bone regeneration. However, processing technologies adopted so far do not allow for the synthesis of scaffolds with suitable mechanical properties. Also, conventional sintering processes result in glass de-vitrification, which generates concerns about bioactivity. In this work, we studied the bioactivity and the mechanical properties of Bioglass(®) based scaffolds, produced via a powder technology inspired process. The scaffolds showed compressive strengths in the range of 5-40 MPa, i.e. in the upper range of values reported so far for these materials, had tunable porosity, in the range between 55 and 77%, and pore sizes that are optimal for bone tissue regeneration (100-500 μm). We immersed the scaffolds in simulated body fluid (SBF) for 28 d and analyzed the evolution of the scaffold mechanical properties and microstructure. Even if, after sintering, partial de-vitrification occurred, immersion in SBF caused ion release and the formation of a Ca-P coating within 2 d, which reached a thickness of 10-15 μm after 28 d. This coating contained both hydroxyapatite and an amorphous background, indicating microstructural amorphization of the base material. Scaffolds retained a good compressive strength and structural integrity also after 28 d of immersion (6 MPa compressive strength). The decrease in mechanical properties was mainly related to the increase in porosity, caused by its dissolution, rather than to the amorphization process and the formation of a Ca-P coating. These results suggest that Bioglass(®) based scaffolds produced via powder metallurgy-inspired technique are excellent candidates for bone regeneration applications.

  14. Pulsed laser deposition of hydroxyapatite thin films

    Czech Academy of Sciences Publication Activity Database

    Koch, C.F.; Johnson, S.; Kumar, D.; Jelínek, Miroslav; Chrisey, D.B.; Doraiswamy, A.; Jin, C.; Narayan, R.J.; Mihailescu, I. N.

    2007-01-01

    Roč. 27, - (2007), s. 484-494 ISSN 0928-4931 Institutional research plan: CEZ:AV0Z10100522 Keywords : hydroxyapatite * pulsed laser deposition * bioactive ceramic s Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.486, year: 2007

  15. Extrusion-based 3D printing of poly(propylene fumarate) scaffolds with hydroxyapatite gradients

    Science.gov (United States)

    Trachtenberg, Jordan E.; Placone, Jesse K.; Smith, Brandon T.; Fisher, John P.; Mikos, Antonios G.

    2017-01-01

    The primary focus of this work is to present the current challenges of printing scaffolds with concentration gradients of nanoparticles with an aim to improve the processing of these scaffolds. Furthermore, we address how print fidelity is related to material composition and emphasize the importance of considering this relationship when developing complex scaffolds for bone implants. The ability to create complex tissues is becoming increasingly relevant in the tissue engineering community. For bone tissue engineering applications, this work demonstrates the ability to use extrusion-based printing techniques to control the spatial deposition of hydroxyapatite (HA) nanoparticles in a 3D composite scaffold. In doing so, we combined the benefits of synthetic, degradable polymers, such as poly(propylene fumarate) (PPF), with osteoconductive HA nanoparticles that provide robust compressive mechanical properties. Furthermore, the final 3D printed scaffolds consisted of well-defined layers with interconnected pores, two critical features for a successful bone implant. To demonstrate a controlled gradient of HA, thermogravimetric analysis was carried out to quantify HA on a per-layer basis. Moreover, we non-destructively evaluated the tendency of HA particles to aggregate within PPF using micro-computed tomography (µCT). This work provides insight for proper fabrication and characterization of composite scaffolds containing particle gradients and has broad applicability for future efforts in fabricating complex scaffolds for tissue engineering applications. PMID:28125380

  16. Water-based sol-gel synthesis of hydroxyapatite: process development.

    Science.gov (United States)

    Liu, D M; Troczynski, T; Tseng, W J

    2001-07-01

    Hydroxyapatite (HA) ceramics were synthesized using a sol-gel route with triethyl phosphite and calcium nitrate as phosphorus and calcium precursors, respectively. Two solvents, water and anhydrous ethanol, were used as diluting media for HA sol preparation. The sols were stable and no gelling occurred in ambient environment for over 5 days. The sols became a white gel only after removal of the solvents at 60 degrees C. X-ray diffraction showed that apatitic structure first appeared at a temperature as low as 350 degrees C. The crystal size and the HA content in both gels increase with increasing calcination temperature. The type of initial diluting media (i.e., water vs. anhydrous ethanol) did not affect the microstructural evolution and crystallinity of the resulting HA ceramic. The ethanol-based sol dip-coated onto a Ti substrate, followed by calcination at 450 degrees C, was found to be porous with pore size ranging from 0.3 to 1 microm. This morphology is beneficial to the circulation of physiological fluid when the coating is used for biomedical applications. The satisfactory adhesion between the coating and substrate suggests its suitability for load-bearing uses.

  17. Development of Drug Loaded Nanoparticles Binding to Hydroxyapatite Based on a Bisphosphonate Modified Nonionic Surfactant

    Directory of Open Access Journals (Sweden)

    Jiabin Zhang

    2015-01-01

    Full Text Available This study aimed at development of drug loaded nanoparticles which could bind to hydroxyapatite (HA to construct drug or growth factor releasing bone graft substitutes. To this end, the terminal hydroxyl group of a nonionic surfactant Brij 78 (polyoxyethylene (20 stearyl ether was first modified with pamidronate (Pa. Using Pa-Brij 78 as both a surfactant and an affinity ligand to HA, three different Pa surface functionalized nanoparticles were prepared, named as solid lipid nanoparticles (Pa-SNPs, nanoemulsions (Pa-NEMs, and PLGA nanoparticles (Pa-PNPs. A model drug curcumin was successfully encapsulated in the three nanoparticles. The sizes of Pa-NEM and Pa-PNP were around 150 nm and the size of Pa-SNP was around 90 nm with polydispersity indexes (PDIs less than 0.20. Drug encapsulation efficiencies of the three nanoparticles were all greater than 85%. Furthermore, the order of binding affinity of the nanoparticles to HA was Pa-PNP>Pa-NEM=Pa-SNP. After lyophilization, the sizes of the three nanoparticles were increased about 0.5–2.0-fold but their binding affinities to HA were almost the same as the fresh prepared nanoparticles. In conclusion, a Pa-modified Brij 78 was synthesized and used for fabrication of a series of drug loaded nanoparticles to construct drug-eluting HA-based bone graft substitutes.

  18. Development of amperometric L-tyrosine sensor based on Fe-doped hydroxyapatite nanoparticles

    International Nuclear Information System (INIS)

    Kanchana, P.; Lavanya, N.; Sekar, C.

    2014-01-01

    A novel biosensor based on Fe-doped hydroxyapatite (Fe-HA) nanoparticles and tyrosinase has been developed for the detection of L-tyrosine. Nanostructured Fe-HA was synthesized by a simple microwave irradiation method, and its phase formation, morphology and magnetic property were examined by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Electrochemical performance of the nano Fe-HA/tyrosinase modified glassy carbon electrode (GCE) for detection of L-tyrosine was investigated by cyclic voltammetry (CV) and amperometric methods. The fabricated biosensor exhibited a linear response to L-tyrosine over a wide concentration range of 1.0 × 10 −7 to 1.0 × 10 −5 M with a detection limit of 245 nM at pH 7.0. In addition, the fabricated sensor showed an excellent selectivity, good reproducibility, long-term stability and anti-interference towards the determination of L-tyrosine. - Highlights: • A novel amperometric L-tyrosine biosensor has been fabricated using nanostructured Fe-HA. • The fabricated sensor exhibits a wide linear range, good stability and high reproducibility. • Fe-HA assists microenvironment and direct electron transfer between enzyme and electrode surface. • The nano Fe-HA and electrode fabrication procedure are simple and less expensive

  19. Novel synthesis and characterization of a collagen-based biopolymer initiated by hydroxyapatite nanoparticles.

    Science.gov (United States)

    Bhuiyan, D; Jablonsky, M J; Kolesov, I; Middleton, J; Wick, T M; Tannenbaum, R

    2015-03-01

    In this study, we developed a novel synthesis method to create a complex collagen-based biopolymer that promises to possess the necessary material properties for a bone graft substitute. The synthesis was carried out in several steps. In the first step, a ring-opening polymerization reaction initiated by hydroxyapatite nanoparticles was used to polymerize d,l-lactide and glycolide monomers to form poly(lactide-co-glycolide) co-polymer. In the second step, the polymerization product was coupled with succinic anhydride, and subsequently was reacted with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide as the cross-linking agent, in order to activate the co-polymer for collagen attachment. In the third and final step, the activated co-polymer was attached to calf skin collagen type I, in hydrochloric acid/phosphate buffer solution and the precipitated co-polymer with attached collagen was isolated. The synthesis was monitored by proton nuclear magnetic resonance, infrared and Raman spectroscopies, and the products after each step were characterized by thermal and mechanical analysis. Calculations of the relative amounts of the various components, coupled with initial dynamic mechanical analysis testing of the resulting biopolymer, afforded a preliminary assessment of the structure of the complex biomaterial formed by this novel polymerization process. Copyright © 2015. Published by Elsevier Ltd.

  20. Fabrication and In Vitro Evaluation of Nanosized Hydroxyapatite/Chitosan-Based Tissue Engineering Scaffolds

    Directory of Open Access Journals (Sweden)

    Tao Sun

    2014-01-01

    Full Text Available Composite scaffolds based on biodegradable natural polymer and osteoconductive hydroxyapatite (HA nanoparticles can be promising for a variety of tissue engineering (TE applications. This study addressed the fabrication of three-dimensional (3D porous composite scaffolds composed of HA and chitosan fabricated via thermally induced phase separation and freeze-drying technique. The scaffolds produced were subsequently characterized in terms of microstructure, porosity, and mechanical property. In vitro degradation and in vitro biological evaluation were also investigated. The scaffolds were highly porous and had interconnected pore structures. The pore sizes ranged from several microns to a few hundred microns. The incorporated HA nanoparticles were well mixed and physically coexisted with chitosan in composite scaffold structures. The addition of 10% (w/w HA nanoparticles to chitosan enhanced the compressive mechanical properties of composite scaffold compared to pure chitosan scaffold. In vitro degradation results in phosphate buffered saline (PBS showed slower uptake properties of composite scaffolds. Moreover, the scaffolds showed positive response to mouse fibroblast L929 cells attachment. Overall, the findings suggest that HA/chitosan composite scaffolds could be suitable for TE applications.

  1. Carbon-centered radicals in γ-irradiated bone substituting biomaterials based on hydroxyapatite.

    Science.gov (United States)

    Sadlo, Jaroslaw; Strzelczak, Grazyna; Lewandowska-Szumiel, Malgorzata; Sterniczuk, Marcin; Pajchel, Lukasz; Michalik, Jacek

    2012-09-01

    Gamma irradiated synthetic hydroxyapatite, bone substituting materials NanoBone(®) and HA Biocer were examined using EPR spectroscopy and compared with powdered human compact bone. In every case, radiation-induced carbon centered radicals were recorded, but their molecular structures and concentrations differed. In compact bone and synthetic hydroxyapatite the main signal assigned to the CO(2) (-) anion radical was stable, whereas the signal due to the CO(3) (3-) radical dominated in NanoBone(®) and HA Biocer just after irradiation. However, after a few days of storage of these samples, also a CO(2) (-) signal was recorded. The EPR study of irradiated compact bone and the synthetic graft materials suggest that their microscopic structures are different. In FT-IR spectra of NanoBone(®), HA Biocer and synthetic hydroxyapatite the HPO(4) (2-) and CO(3) (2-) in B-site groups are detected, whereas in compact bone signals due to collagen dominate.

  2. Specialized probes based on hydroxyapatite calcium for heart tissues research by atomic force microscopy

    International Nuclear Information System (INIS)

    Zhukov, Mikhail; Golubok, Alexander; Gulyaev, Nikolai

    2016-01-01

    The new specialized AFM-probes with hydroxyapatite structures for atomic force microscopy of heart tissues calcification were created and studied. A process of probe fabrication is demonstrated. The adhesive forces between specialized hydroxyapatite probe and endothelium/subendothelial layers were investigated. It was found that the adhesion forces are significantly higher for the subendothelial layers. We consider that it is connected with the formation and localization of hydroxyapatite in the area of subendothelial layers of heart tissues. In addition, the roughness analysis and structure visualization of the endothelial surface of the heart tissue were carried out. The results show high efficiency of created specialized probes at study a calcinations process of the aortic heart tissues.

  3. Vibrational algorithms for quantitative crystallographic analyses of hydroxyapatite-based biomaterials: I, theoretical foundations.

    Science.gov (United States)

    Pezzotti, Giuseppe; Zhu, Wenliang; Boffelli, Marco; Adachi, Tetsuya; Ichioka, Hiroaki; Yamamoto, Toshiro; Marunaka, Yoshinori; Kanamura, Narisato

    2015-05-01

    The Raman spectroscopic method has quantitatively been applied to the analysis of local crystallographic orientation in both single-crystal hydroxyapatite and human teeth. Raman selection rules for all the vibrational modes of the hexagonal structure were expanded into explicit functions of Euler angles in space and six Raman tensor elements (RTE). A theoretical treatment has also been put forward according to the orientation distribution function (ODF) formalism, which allows one to resolve the statistical orientation patterns of the nm-sized hydroxyapatite crystallite comprised in the Raman microprobe. Close-form solutions could be obtained for the Euler angles and their statistical distributions resolved with respect to the direction of the average texture axis. Polarized Raman spectra from single-crystalline hydroxyapatite and textured polycrystalline (teeth enamel) samples were compared, and a validation of the proposed Raman method could be obtained through confirming the agreement between RTE values obtained from different samples.

  4. Structure-solubility relationships in fluoride-containing phosphate based bioactive glasses

    Science.gov (United States)

    Shaharyar, Yaqoot

    The dissolution of fluoride-containing bioactive glasses critically affects their biomedical applications. Most commercial fluoride-releasing bioactive glasses have been designed in the soda-lime-silica system. However, their relatively slow chemical dissolution and the adverse effect of fluoride on their bioactivity are stimulating the study of novel biodegradable materials with higher bioactivity, such as biodegradable phosphate-based bioactive glasses, which can be a viable alternative for applications where a fast release of active ions is sought. In order to design new biomaterials with controlled degradability and high bioactivity, it is essential to understand the connection between chemical composition, molecular structure, and solubility in physiological fluids.Accordingly, in this work we have combined the strengths of various experimental techniques with Molecular Dynamics (MD) simulations, to elucidate the impact of fluoride ions on the structure and chemical dissolution of bioactive phosphate glasses in the system: 10Na2O - (45-x) CaO - 45P2O5 - xCaF2, where x varies between 0 -- 10 mol.%. NMR and MD data reveal that the medium-range atomic-scale structure of thse glasses is dominated by Q2 phosphate units followed by Q1 units, and the MD simulations further show that fluoride tends to associate with network modifier cations to form alkali/alkaline-earth rich ionic aggregates. On a macroscopic scale, we find that incorporating fluoride in phosphate glasses does not affect the rate of apatite formation on the glass surface in simulated body fluid (SBF). However, fluoride has a marked favorable impact on the glass dissolution in deionized water. Similarly, fluoride incorporation in the glasses results in significant weight gain due to adsorption of water (in the form of OH ions). These macroscopic trends are discussed on the basis of the F effect on the atomistic structure of the glasses, such as the F-induced phosphate network re-polymerization, in a

  5. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility

    International Nuclear Information System (INIS)

    Verné, Enrica; Bruno, Matteo; Miola, Marta; Maina, Giovanni; Bianco, Carlotta; Cochis, Andrea; Rimondini, Lia

    2015-01-01

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO 2 –Na 2 O–CaO–P 2 O 5 –FeO–Fe 2 O 3 and contains magnetite (Fe 3 O 4 ) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite – HAp – layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. - Highlights: • An in vitro biological characterization was carried out on ferromagnetic and bioactive composite cements. • No release of iron was revealed in the physiological solution. • Bioactivity tests show hydroxyapatite precipitates

  6. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Verné, Enrica, E-mail: enrica.verne@polito.it [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Bruno, Matteo [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Miola, Marta [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Maina, Giovanni; Bianco, Carlotta [Traumatology Orthopedics and Occupational Medicine Dept., Università di Torino, Via G. Zuretti 29, 10126 Torino (Italy); Cochis, Andrea [Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Rimondini, Lia [Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9, 50121 Firenze (Italy)

    2015-08-01

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO{sub 2}–Na{sub 2}O–CaO–P{sub 2}O{sub 5}–FeO–Fe{sub 2}O{sub 3} and contains magnetite (Fe{sub 3}O{sub 4}) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite – HAp – layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. - Highlights: • An in vitro biological characterization was carried out on ferromagnetic and bioactive composite cements. • No release of iron was revealed in the physiological solution. • Bioactivity tests

  7. Electroplasma coatings based on silicon-containing hydroxyapatite: Technology and properties

    Science.gov (United States)

    Lyasnikova, A. V.; Markelova, O. A.

    2016-09-01

    IR analysis and the plasma deposition of silicon-containing hydroxyapatite powder have been carried out. It has been shown that the coating exhibits developed morphology and consists of molten powder (including nanosize) particles uniformly distributed over the entire surface. The adhesion characteristics have been calculated and scanning electron microscope images of the resultant coating have been analyzed.

  8. Efficacy of a mouthrinse based on hydroxyapatite to reduce initial bacterial colonisation in situ.

    Science.gov (United States)

    Kensche, A; Holder, C; Basche, S; Tahan, N; Hannig, C; Hannig, M

    2017-08-01

    The present in situ - investigation aimed to specify the impact of pure hydroxyapatite microclusters on initial bioadhesion and bacterial colonization at the tooth surface. Pellicle formation was carried out in situ on bovine enamel slabs (9 subjects). After 1min of pellicle formation rinses with 8ml of hydroxyapatite (HA) microclusters (5%) in bidestilled water or chlorhexidine 0.2% were performed. As negative control no rinse was adopted. In situ biofilm formation was promoted by the intraoral slab exposure for 8h overnight. Afterwards initial bacterial adhesion was quantified by DAPI staining and bacterial viability was determined in vivo/in vitro by live/dead-staining (BacLight). SEM analysis evaluated the efficacy of the mouthrinse to accumulate hydroxyapatite microclusters at the specimens' surface and spit-out samples of the testsolution were investigated by TEM. Compared to the control (2.36×10 6 ±2.01×10 6 bacteria/cm 2 ), significantly reduced amounts of adherent bacteria were detected on specimens rinsed with chlorhexidine 0.2% (8.73×10 4 ±1.37×10 5 bacteria/cm 2 ) and likewise after rinses with the hydroxyapatite testsolution (2.08×10 5 ±2.85×10 5 bacteria/cm 2 , phydroxyapatite microclusters at the tooth surface. Adhesive interactions of HA-particles with oral bacteria were shown by TEM. Hydroxyapatite microclusters reduced initial bacterial adhesion to enamel in situ considerably and could therefore sensibly supplement current approaches in dental prophylaxis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Physicochemical and bioactive properties of innovative resin-based materials containing functional halloysite-nanotubes fillers.

    Science.gov (United States)

    Degrazia, Felipe Weidenbach; Leitune, Vicente Castelo Branco; Takimi, Antonio Shigueaki; Collares, Fabrício Mezzomo; Sauro, Salvatore

    2016-09-01

    This study aimed to assess the degree of conversion, microhardness, solvent degradation, contact angle, surface free energy and bioactivity (e.g., mineral precipitation) of experimental resin-based materials containing, pure or triclosan-encapsulated, aluminosilicate-(halloysite) nanotubes. An experimental resin blend was prepared using bis-GMA/TEGDMA, 75/25wt% (control). Halloysite nanotubes (HNT) doped with or without triclosan (TCN) were first analyzed using transmission electron microscopy (TEM). HNT or HNT/TCN fillers were incorporated into the resin blend at different concentrations (5, 10, and 20wt%). Seven experimental resins were created and the degree of conversion, microhardness, solvent degradation and contact angle were assessed. Bioactive mineral precipitation induced by the experimental resins was evaluated through Raman spectroscopy and SEM-EDX. TEM showed a clear presence of TCN particles inside the tubular lumen and along the outer surfaces of the halloysite nanotubes. The degree of conversion, surface free energy, microhardness, and mineral deposition of polymers increased with higher amount of HNTs. Conversely, the higher the amount (20wt%) of TCN-loaded HNTs the lower the microhardness of the experimental resins. The incorporation of pure or TCN-loaded aluminosilicate-(halloysite) nanotubes into resin-based materials increase the bioactivity of such experimental restorative materials and promotes mineral deposition. Therefore, innovative resin-based materials containing functional halloysite-nanotube fillers may represent a valuable alternative for therapeutic minimally invasive treatments. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Wear Behavior of Plasma Spray Deposited and Post Heat-Treated Hydroxyapatite (HA)-Based Composite Coating on Titanium Alloy (Ti-6Al-4V) Substrate

    Science.gov (United States)

    Kumari, Renu; Majumdar, Jyotsna Dutta

    2018-04-01

    The present study concerns a detailed evaluation of wear resistance property of plasma spray deposited composite hydroxyapatite (HA)-based (HA-50 wt pct TiO2 and HA-10 wt pct ZrO2) bioactive coatings developed on Ti-6Al-4V substrate and studying the effect of heat treatment on it. Heat treatment of plasma spray deposited samples has been carried out at 650 °C for 2 hours (for HA-50 wt pct TiO2 coating) and at 750 °C for 2 hours (for HA-10 wt pct ZrO2 coating). There is significant deterioration in wear resistance for HA-50 wt pctTiO2 coating and a marginal deterioration in wear resistance for HA-10 wt pct ZrO2 coating in as-sprayed state (as compared to as-received Ti-6Al-4V) which is, however, improved after heat treatment. The coefficient of friction is marginally increased for both HA-50 wt pct TiO2 and HA-10 wt pct ZrO2 coatings in as-sprayed condition as compared to Ti-6Al-4V substrate. However, coefficient of friction is decreased for both HA-50 wt pct TiO2 and HA-10 wt pct ZrO2 coatings after heat-treated condition as compared to Ti-6Al-4V substrate. The maximum improvement in wear resistance property is, however, observed for HA-10 wt pct ZrO2 sample after heat treatment. The mechanism of wear has been investigated.

  11. Fabrication, characterization, and in vitro evaluation of poly(lactic acid glycolic acid)/nano-hydroxyapatite composite microsphere-based scaffolds for bone tissue engineering in rotating bioreactors.

    Science.gov (United States)

    Lv, Qing; Nair, Lakshmi; Laurencin, Cato T

    2009-12-01

    Dynamic flow culture bioreactor systems have been shown to enhance in vitro bone tissue formation by facilitating mass transfer and providing mechanical stimulation. Our laboratory has developed a biodegradable poly (lactic acid glycolic acid) (PLAGA) mixed scaffold consisting of lighter-than-water (LTW) and heavier-than-water (HTW) microspheres as potential matrices for engineering tissue using a high aspect ratio vessel (HARV) rotating bioreactor system. We have demonstrated enhanced osteoblast differentiation and mineralization on PLAGA scaffolds in the HARV rotating bioreactor system when compared with static culture. The objective of the present study is to improve the mechanical properties and bioactivity of polymeric scaffolds by designing LTW polymer/ceramic composite scaffolds suitable for dynamic culture using a HARV bioreactor. We employed a microsphere sintering method to fabricate three-dimensional PLAGA/nano-hydroxyapatite (n-HA) mixed scaffolds composed of LTW and HTW composite microspheres. The mechanical properties, pore size and porosity of the composite scaffolds were controlled by varying parameters, such as sintering temperature, sintering time, and PLAGA/n-HA ratio. The PLAGA/n-HA (4:1) scaffold sintered at 90 degrees C for 3 h demonstrated the highest mechanical properties and an appropriate pore structure for bone tissue engineering applications. Furthermore, evaluation human mesenchymal stem cells (HMSCs) response to PLAGA/n-HA scaffolds was performed. HMSCs on PLAGA/n-HA scaffolds demonstrated enhanced proliferation, differentiation, and mineralization when compared with those on PLAGA scaffolds. Therefore, PLAGA/n-HA mixed scaffolds are promising candidates for HARV bioreactor-based bone tissue engineering applications. Copyright 2008 Wiley Periodicals, Inc.

  12. Effect of modification substrate on the microstructure of hydroxyapatite coating

    International Nuclear Information System (INIS)

    Realpe-Jaramillo, J; Morales-Morales, J A; González-Sánchez, J A; Cabanzo, R; Mejía-Ospino, E; Rodríguez-Pereira, J

    2017-01-01

    Bioactive hydroxyapatite (HA) coatings were fabricated by a precipitation, sol-gel and dip-coating method. The effects of the aging time and the base used to adjust pH and substrate materials on the phases and microstructures of HA coatings were studied by field emission scanning electron microscopy FESEM, energy dispersive spectroscopy EDS, X-ray photoelectron spectroscopy XPS, and the vibrations of the phosphate groups were determined by Raman spectroscopy. The results showed that all the films were composed of the phases of TiO 2 and HA. With coated titanium substrate with TiO 2 , the crystallinity of the HA coating increases, the structure became more compact and the Ca/P ratio increased because of the loss of P in the films. The addition of sodium hydroxide (adjusting the pH level to about 10) can increase the HA content in the coating. XPS and EDS results for steel substrate and titanium showed poor calcium content as obtained with a Ca/P ratio of 1.38 and 1.58, respectively, composition is similar to that of natural apatite. However, spectroscopic results suggest the presence of a mixture of hydroxyapatite and octacalcium phosphate. The different substrate materials have a high influence on the microstructure of the separated double films. However, hydroxyapatite nanopowders coatings were obtained using a simple method, with potential biomedical applications. (paper)

  13. Effect of modification substrate on the microstructure of hydroxyapatite coating

    Science.gov (United States)

    Realpe-Jaramillo, J.; Morales-Morales, J. A.; González-Sánchez, J. A.; Cabanzo, R.; Mejía-Ospino, E.; Rodríguez-Pereira, J.

    2017-01-01

    Bioactive hydroxyapatite (HA) coatings were fabricated by a precipitation, sol-gel and dip-coating method. The effects of the aging time and the base used to adjust pH and substrate materials on the phases and microstructures of HA coatings were studied by field emission scanning electron microscopy FESEM, energy dispersive spectroscopy EDS, X-ray photoelectron spectroscopy XPS, and the vibrations of the phosphate groups were determined by Raman spectroscopy. The results showed that all the films were composed of the phases of TiO2 and HA. With coated titanium substrate with TiO2, the crystallinity of the HA coating increases, the structure became more compact and the Ca/P ratio increased because of the loss of P in the films. The addition of sodium hydroxide (adjusting the pH level to about 10) can increase the HA content in the coating. XPS and EDS results for steel substrate and titanium showed poor calcium content as obtained with a Ca/P ratio of 1.38 and 1.58, respectively, composition is similar to that of natural apatite. However, spectroscopic results suggest the presence of a mixture of hydroxyapatite and octacalcium phosphate. The different substrate materials have a high influence on the microstructure of the separated double films. However, hydroxyapatite nanopowders coatings were obtained using a simple method, with potential biomedical applications.

  14. Bioactive glass coupling with natural polyphenols: Surface modification, bioactivity and anti-oxidant ability

    Energy Technology Data Exchange (ETDEWEB)

    Cazzola, Martina [Politecnico di Torino, Department of Applied Science and Technology, Institute of Materials Physics and Engineering, C.so Duca degli Abruzzi 24, Torino 10129 (Italy); Corazzari, Ingrid [Università degli Studi di Torino, Department of Chemistry, Via Pietro Giuria 7, Torino 10125 (Italy); Centro Interdipartimentale “G. Scansetti” per lo studio degli amianti e di altri particolati nocivi, Via Pietro Giuria 9, 10125 Torino (Italy); Prenesti, Enrico [Università degli Studi di Torino, Department of Chemistry, Via Pietro Giuria 7, Torino 10125 (Italy); Bertone, Elisa [Politecnico di Torino, Department of Applied Science and Technology, Institute of Materials Physics and Engineering, C.so Duca degli Abruzzi 24, Torino 10129 (Italy); Vernè, Enrica, E-mail: enrica.verne@polito.it [Politecnico di Torino, Department of Applied Science and Technology, Institute of Materials Physics and Engineering, C.so Duca degli Abruzzi 24, Torino 10129 (Italy); Ferraris, Sara [Politecnico di Torino, Department of Applied Science and Technology, Institute of Materials Physics and Engineering, C.so Duca degli Abruzzi 24, Torino 10129 (Italy)

    2016-03-30

    Graphical abstract: - Highlights: • Surface functionalization of bioactive glass with biomolecules has been optimized. • Biomolecules are present and active on the glass surface after functionalization. • Biomolecules affect deposition kinetics and morphology of hydroxyapatite. • Free radical scavenging activity is seen for the first time on bioactive glasses. - Abstract: Polyphenols are actually achieving an increasing interest due to their potential health benefits, such as antioxidant, anticancer, antibacterial and bone stimulation abilities. However their poor bioavailability and stability hamper an effective clinical application as therapeutic principles. The opportunity to couple these biomolecules with synthetic biomaterials, in order to obtain local delivery at the site of interest, improve their bioavailability and stability and combine their properties with the ones of the substrate, is a challenging opportunity for the biomedical research. A silica based bioactive glass, CEL2, has been successfully coupled with gallic acid and natural polyphenols extracted from red grape skins and green tea leaves. The effectiveness of grafting has been verified by means of XPS analyses and the Folin&Ciocalteu tests. In vitro bioactivity has been investigated by soaking in simulated body fluid (SBF). Surface modification after functionalization and early stage reactivity in SBF have been studied by means of zeta potential electrokinetic measurements in KCl and SBF. Finally the antioxidant properties of bare and modified bioactive glasses has been investigated by means of the evaluation of free radical scavenging activity by Electron Paramagnetic Resonance (EPR)/spin trapping technique after UV photolysis of H{sub 2}O{sub 2} highlighting scavenging activity of the bioactive glass.

  15. Bioactive albumin-based carriers for tumour chemotherapy.

    Science.gov (United States)

    Shahzad, Yasser; Khan, Ikram Ullah; Hussain, Talib; Alamgeer; Serra, Christophe A; Rizvi, Syed A A; Gerber, Minja; du Plessis, Jeanetta

    2014-01-01

    Proteins are posed as the natural counterpart of the synthetic polymers for the development of drug delivery systems and few of them, have been regarded safe for drug delivery purposes by the United States Food and Drug Administration (FDA). Serum albumin is the most abundant protein in human blood. Interest in the exploration of pharmaceutical applications of albumin-based drug delivery carriers, especially for the delivery of chemotherapeutic agents, has increased in recent years. Albumin has several advantages over synthetic polymers, as it is biocompatible, biodegradable, has low cytotoxicity and has an excellent binding capacity with various drugs. Micro- and nano-carriers not only protect active pharmaceutical ingredients against degradation, but also offer a prolonged release of drugs in a controlled fashion. Since existing tumour chemotherapeutic agents neither target tumour cells, nor are they specific to tumour cells, a slow release of drugs from carriers would be beneficial in targeting carcinogenic cells intracellularly. This article aims at providing an overview of pharmaceutical applications of albumin as a drug delivery carrier in tumour chemotherapy.

  16. Tantalum-doped hydroxyapatite thin films: Synthesis and characterization

    International Nuclear Information System (INIS)

    Ligot, S.; Godfroid, T.; Music, D.; Bousser, E.; Schneider, J.M.; Snyders, R.

    2012-01-01

    To achieve a good bioactivity, magnetron-sputtered (MS) hydroxyapatite (HA) coatings have to be stoichiometric and crystalline. It has also been suggested that doping HA with metallic elements improves its bioactivity but frequently reduces its Young’s modulus. Therefore, efforts are still necessary to identify adequate growth conditions, good doping elements and finally to grow doped HA films. In a first attempt, HA films have been synthesized by MS. Our conditions enabled us to grow at ∼10 nm min −1 stoichiometric and crystallized HA coatings that presented a strong texture. The latter is discussed in view of the competitive growth of the material under the strong electron and ion bombardments used here. Based on ab initio calculations identifying Ta as a promising doping element, we then investigated the growth of Ta-doped hydroxyapatite (HA:Ta) by magnetron co-sputtering. The HA:Ta films were in situ crystallized. Our data reveals that for Ta contents <4.5 at.%, Ta could substitute Ca in the HA cell. For higher doping contents, a deviation from the stoichiometric compound is observed and CaO appears. By nanoindentation, we have measured an elastic modulus of 120 ± 9 GPa for a Ta content of 3 at.%. This value is very close to the value of 110 GPa calculated by ab initio calculations, supporting the substitution scenario. The elasticity drop may be understood by screening of the ionic interaction between constituents in HA upon Ta incorporation.

  17. Cyndi: a multi-objective evolution algorithm based method for bioactive molecular conformational generation.

    Science.gov (United States)

    Liu, Xiaofeng; Bai, Fang; Ouyang, Sisheng; Wang, Xicheng; Li, Honglin; Jiang, Hualiang

    2009-03-31

    Conformation generation is a ubiquitous problem in molecule modelling. Many applications require sampling the broad molecular conformational space or perceiving the bioactive conformers to ensure success. Numerous in silico methods have been proposed in an attempt to resolve the problem, ranging from deterministic to non-deterministic and systemic to stochastic ones. In this work, we described an efficient conformation sampling method named Cyndi, which is based on multi-objective evolution algorithm. The conformational perturbation is subjected to evolutionary operation on the genome encoded with dihedral torsions. Various objectives are designated to render the generated Pareto optimal conformers to be energy-favoured as well as evenly scattered across the conformational space. An optional objective concerning the degree of molecular extension is added to achieve geometrically extended or compact conformations which have been observed to impact the molecular bioactivity (J Comput -Aided Mol Des 2002, 16: 105-112). Testing the performance of Cyndi against a test set consisting of 329 small molecules reveals an average minimum RMSD of 0.864 A to corresponding bioactive conformations, indicating Cyndi is highly competitive against other conformation generation methods. Meanwhile, the high-speed performance (0.49 +/- 0.18 seconds per molecule) renders Cyndi to be a practical toolkit for conformational database preparation and facilitates subsequent pharmacophore mapping or rigid docking. The copy of precompiled executable of Cyndi and the test set molecules in mol2 format are accessible in Additional file 1. On the basis of MOEA algorithm, we present a new, highly efficient conformation generation method, Cyndi, and report the results of validation and performance studies comparing with other four methods. The results reveal that Cyndi is capable of generating geometrically diverse conformers and outperforms other four multiple conformer generators in the case of

  18. Cyndi: a multi-objective evolution algorithm based method for bioactive molecular conformational generation

    Directory of Open Access Journals (Sweden)

    Li Honglin

    2009-03-01

    Full Text Available Abstract Background Conformation generation is a ubiquitous problem in molecule modelling. Many applications require sampling the broad molecular conformational space or perceiving the bioactive conformers to ensure success. Numerous in silico methods have been proposed in an attempt to resolve the problem, ranging from deterministic to non-deterministic and systemic to stochastic ones. In this work, we described an efficient conformation sampling method named Cyndi, which is based on multi-objective evolution algorithm. Results The conformational perturbation is subjected to evolutionary operation on the genome encoded with dihedral torsions. Various objectives are designated to render the generated Pareto optimal conformers to be energy-favoured as well as evenly scattered across the conformational space. An optional objective concerning the degree of molecular extension is added to achieve geometrically extended or compact conformations which have been observed to impact the molecular bioactivity (J Comput -Aided Mol Des 2002, 16: 105–112. Testing the performance of Cyndi against a test set consisting of 329 small molecules reveals an average minimum RMSD of 0.864 Å to corresponding bioactive conformations, indicating Cyndi is highly competitive against other conformation generation methods. Meanwhile, the high-speed performance (0.49 ± 0.18 seconds per molecule renders Cyndi to be a practical toolkit for conformational database preparation and facilitates subsequent pharmacophore mapping or rigid docking. The copy of precompiled executable of Cyndi and the test set molecules in mol2 format are accessible in Additional file 1. Conclusion On the basis of MOEA algorithm, we present a new, highly efficient conformation generation method, Cyndi, and report the results of validation and performance studies comparing with other four methods. The results reveal that Cyndi is capable of generating geometrically diverse conformers and outperforms

  19. Enhanced osteoconductivity of sodium-substituted hydroxyapatite by system instability.

    Science.gov (United States)

    Sang Cho, Jung; Um, Seung-Hoon; Su Yoo, Dong; Chung, Yong-Chae; Hye Chung, Shin; Lee, Jeong-Cheol; Rhee, Sang-Hoon

    2014-07-01

    The effect of substituting sodium for calcium on enhanced osteoconductivity of hydroxyapatite was newly investigated. Sodium-substituted hydroxyapatite was synthesized by reacting calcium hydroxide and phosphoric acid with sodium nitrate followed by sintering. As a control, pure hydroxyapatite was prepared under identical conditions, but without the addition of sodium nitrate. Substitution of calcium with sodium in hydroxyapatite produced the structural vacancies for carbonate ion from phosphate site and hydrogen ion from hydroxide site of hydroxyapatite after sintering. The total system energy of sodium-substituted hydroxyapatite with structural defects calculated by ab initio methods based on quantum mechanics was much higher than that of hydroxyapatite, suggesting that the sodium-substituted hydroxyapatite was energetically less stable compared with hydroxyapatite. Indeed, sodium-substituted hydroxyapatite exhibited higher dissolution behavior of constituent elements of hydroxyapatite in simulated body fluid (SBF) and Tris-buffered deionized water compared with hydroxyapatite, which directly affected low-crystalline hydroxyl-carbonate apatite forming capacity by increasing the degree of apatite supersaturation in SBF. Actually, sodium-substituted hydroxyapatite exhibited markedly improved low-crystalline hydroxyl-carbonate apatite forming capacity in SBF and noticeably higher osteoconductivity 4 weeks after implantation in calvarial defects of New Zealand white rabbits compared with hydroxyapatite. In addition, there were no statistically significant differences between hydroxyapatite and sodium-substituted hydroxyapatite on cytotoxicity as determined by BCA assay. Taken together, these results indicate that sodium-substituted hydroxyapatite with structural defects has promising potential for use as a bone grafting material due to its enhanced osteoconductivity compared with hydroxyapatite. © 2013 Wiley Periodicals, Inc.

  20. Internal in vitro dosimetry for fish using hydroxyapatite-based EPR detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, D.V. [Urals Division of Russian Academy of Sciences, Institute of Metal Physics, Yekaterinburg (Russian Federation); Ural Federal University, Yekaterinburg (Russian Federation); Shishkina, E.A.; Osipov, D.I.; Pryakhin, E.A. [Urals Research Center for Radiation Medicine, Chelyabinsk (Russian Federation); Razumeev, R.A. [Ural Federal University, Yekaterinburg (Russian Federation)

    2015-08-15

    A number of aquatic ecosystems were exposed to ionizing radiation as a result of the activities of the Mayak Production Association in the Southern Urals, former Soviet Union, in the 1950s. Currently, fishes inhabiting contaminated lakes are being actively studied. These investigations need dosimetric support. In the present paper the results of a pilot study for elaborating an EPR dosimeter which can be used for internal dosimetry in vitro are described. Biological hydroxyapatite is proposed here to be used as a detecting substance. More specifically, small hydroxyapatite grains are proposed for use as point detectors fixed in a solid matrix. After having been pelletized, the detectors were covered by Mylar and placed in the body of a fish to be stored in the fridge for several months. Application of the detectors for internal fish dosimetry demonstrated that the enamel sensitivity is sufficient for passive detection of ionizing radiation in fishes inhabiting contaminated lakes in the Southern Urals. (orig.)

  1. Scaffolds of polycaprolactone with hydroxyapatite fibers

    International Nuclear Information System (INIS)

    Cardoso, Guinea B.C.; Zavaglia, Cecilia A.C.; Arruda, Antonio Celso F.

    2009-01-01

    Scaffolds of poly (ε-caprolactone) has been studied in many researches in tissue engineering. The used of hydroxyapatite fibers, allowed increase its resistance mechanical, beside the character bioactive and osteoconductive. Improving, its role in tissue engineering. The aim in this study was developed polycaprolactone matrix with dispersed hydroxyapatite fibers. The characterizations were by scanning electron microscopy (SEM), X- Ray Diffractometer (XRD), X-Ray Fluorescence (XRF) and Energy dispersive X-Ray Detector (EDX). Was able reviewed its composition, morphology and possible contaminations. The results were scaffolds with porosity and distribution of the fibers in all its area. (author)

  2. Stabilization and solidification of a heavy metal contaminated site soil using a hydroxyapatite based binder

    OpenAIRE

    Xia, Wei-Yi; Feng, Ya-Song; Jin, Fei; Zhang, Li-Ming; Du, Yan-Jun

    2017-01-01

    Synthetic hydroxyapatite (HA) is an efficient and environment-friendly material for the remediation of heavy metal contaminated soils. However, the application of conventional HA powder in stabilizing contaminated soils is limited, due to high cost of final products, difficulties in synthesizing purified HA crystals. A new binder named SPC, which composes of single superphosphate (SSP) and calcium oxide (CaO), is presented as an alternative in this study. HA can form in the soil matrix by an ...

  3. Bioactivity and mineralization of hydroxyapatite with bioglass as sintering aid and bioceramics with Na3Ca6(PO4)5 and Ca5(PO4)2SiO4 in a silicate matrix

    International Nuclear Information System (INIS)

    Demirkiran, Hande; Mohandas, Arunesh; Dohi, Motokazi; Fuentes, Alonso; Nguyen, Kytai; Aswath, Pranesh

    2010-01-01

    Hydroxyapatite and Bioglass-45S5 were sintered together creating new ceramic compositions that yielded increased apatite deposition and osteoblast differentiation and proliferation in vitro compared to hydroxyapatite. The sintered products characterized by X-ray diffraction, revealed hydroxyapatite as the main phase when small quantities (1, 2.5 and 5 wt.%) of bioglass was added. Bioglass behaved as a sintering aid with β-TCP (Ca 3 (PO 4 ) 2 ) being the minor phase. The amount of β-TCP increased with the amount of bioglass added. In compositions with larger additions of bioglass (10 and 25 wt.%), new phases with compositions of calcium phosphate silicate (Ca 5 (PO 4 ) 2 SiO 4 ) and sodium calcium phosphate (Na 3 Ca 6 (PO 4 ) 5 ) were formed respectively within amorphous silicate matrices. In vitro cell culture studies of the ceramic compositions were examined using bone marrow stromal cell (BMSC). Cell proliferation and differentiation of bone marrow stromal cells into osteoblasts were determined by Pico Green DNA assays and alkaline phosphatase (ALP) activity, respectively. All hydroxyapatite-bioglass co-sintered ceramics exhibited larger cell proliferation compared to pure hydroxyapatite samples. After 6 days in cell culture, the ceramic with Ca 5 (PO 4 ) 3 SiO 4 in a silicate matrix formed by reacting hydroxyapatite with 10 wt.% bioglass exhibited the maximum proliferation of the BMSC's. The ALP activity was found to be largest in the ceramic with Na 3 Ca 6 (PO 4 ) 5 embedded in a silicate matrix synthesized by reacting hydroxyapatite with 25 wt.% bioglass.

  4. Preparation and characterization of composites based on the blends of collagen, chitosan and hyaluronic acid with nano-hydroxyapatite.

    Science.gov (United States)

    Sionkowska, Alina; Kaczmarek, Beata

    2017-09-01

    3D porous composites based on the blend of chitosan, collagen and hyaluronic acid with the addition of nano-hydroxyapatite were prepared. SEM images for the composites were made and the structure was assessed. Mechanical properties were studied using a Zwick&Roell Testing Mashine. In addition, the porosity and density of composites were measured. The concentration of calcium ions released from the material was detected by the complexometric titration method. The results showed that in 3D porous sponge based on the blend of chitosan, collagen and hyaluronic acid, inorganic particles of nanohydroxyapatite can be incorporated, as well as that the properties of 3D composites depend on the material composition. Mechanical parameters and thermal stability of ternary biopolymeric blends were improved by the addition of hydroxyapatite. Moreover, the porosity of ternary materials was higher than in materials based on pure chitosan or collagen. All composites were characterized by a porous structure with interconnected pores. Calcium ions can be released from the composite during its degradation in water. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Novel bioactive polyester scaffolds prepared from unsaturated resins based on isosorbide and succinic acid

    Energy Technology Data Exchange (ETDEWEB)

    Śmiga-Matuszowicz, Monika, E-mail: monika.smiga-matuszowicz@polsl.pl [Silesian University of Technology, Department of Physical Chemistry and Technology of Polymers, M. Strzody Street 9, 44-100 Gliwice (Poland); Janicki, Bartosz; Jaszcz, Katarzyna; Łukaszczyk, Jan [Silesian University of Technology, Department of Physical Chemistry and Technology of Polymers, M. Strzody Street 9, 44-100 Gliwice (Poland); Kaczmarek, Marcin [Silesian University of Technology, Department of Biomaterials and Medical Devices Engineering, de Gaulle' a Street 66, 41-800 Zabrze (Poland); Lesiak, Marta; Sieroń, Aleksander L. [Medical University of Silesia, Department of General and Molecular Biology and Genetics, Medyków Street 18, 40-752 Katowice (Poland); Simka, Wojciech [Silesian University of Technology, Department of Chemistry, Inorganic Technology and Fuels, B. Krzywoustego Street 6, 44-100 Gliwice (Poland); Mierzwiński, Maciej; Kusz, Damian [Medical University of Silesia, Department of Orthopedics and Traumatology, Ziołowa Street 45, 40-635 Katowice (Poland)

    2014-12-01

    In this study new biodegradable materials obtained by crosslinking poly(3-allyloxy-1,2-propylene succinate) (PSAGE) with oligo(isosorbide maleate) (OMIS) and small amount of methyl methacrylate were investigated. The porous scaffolds were obtained in the presence of a foaming system consisted of calcium carbonate/carboxylic acid mixture, creating in situ porous structure during crosslinking of liquid formulations. The maximum crosslinking temperature and setting time, the cured porous materials morphology as well as the effect of their porosity on mechanical properties and hydrolytic degradation process were evaluated. It was found that the kind of carboxylic acid used in the foaming system influenced compressive strength and compressive modulus of porous scaffolds. The MTS cytotoxicity assay was carried out for OMIS using hFOB1.19 cell line. OMIS resin was found to be non-toxic in wide range of concentrations. On the ground of scanning electron microscopy (SEM) observations and energy X-ray dispersive analysis (EDX) it was found that hydroxyapatite (HA) formation at the scaffolds surfaces within short period of soaking in phosphate buffer solution occurs. After 3 h immersion a compact layer of HA was observed at the surface of the samples. The obtained results suggest potential applicability of resulted new porous crosslinked polymeric materials as temporary bone void fillers. - Highlights: • Isosorbide-based resin was used as a component of biodegradable scaffolds. • CAC/carboxylic acid system was proven as facile method to obtain porous scaffolds. • Porous scaffolds displayed the formation of hydroxyapatite at their surfaces.

  6. Bioactivity evaluation of commercial calcium phosphate-based bioceramics for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Borrós, S.; Mas, A.

    2016-11-01

    Calcium phosphate-based bioceramics constitute a great promise for bone tissue engineering as they chemically resemble to mammalian bone and teeth. Their use is a viable alternative for bone regeneration as it avoids the use of autografts and allografts, which usually involves immunogenic reactions and patient’s discomfort. This work evolves around the study of the bioactivity potential of different commercially available bone substitutes based in calcium phosphate through the characterization of their ionic exchangeability when immersed in simulated body fluid (SBF). (Author)

  7. A review of hydroxyapatite-based coating techniques: Sol-gel and electrochemical depositions on biocompatible metals.

    Science.gov (United States)

    Asri, R I M; Harun, W S W; Hassan, M A; Ghani, S A C; Buyong, Z

    2016-04-01

    New promising techniques for depositing biocompatible hydroxyapatite-based coatings on biocompatible metal substrates for biomedical applications have continuously been exploited for more than two decades. Currently, various experimental deposition processes have been employed. In this review, the two most frequently used deposition processes will be discussed: a sol-gel dip coating and an electrochemical deposition. This study deliberates the surface morphologies and chemical composition, mechanical performance and biological responses of sol-gel dip coating as well as the electrochemical deposition for two different sample conditions, with and without coating. The review shows that sol-gel dip coatings and electrochemical deposition were able to obtain the uniform and homogeneous coating thickness and high adherent biocompatible coatings even in complex shapes. It has been accepted that both coating techniques improve bone strength and initial osseointegration rate. The main advantages and limitations of those techniques of hydroxyapatite-based coatings are presented. Furthermore, the most significant challenges and critical issues are also highlighted. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. LASER-INDUCED BIOACTIVITY IN DENTAL PORCELAIN MODIFIED BY BIOACTIVE GLASS

    Directory of Open Access Journals (Sweden)

    ANASTASIA BEKETOVA

    2012-12-01

    Full Text Available The aim of this study was to investigate the impact of laser-liquid-solid interaction method in the bioactivity of dental porcelain modified by bioactive glass. Forty sol-gel derived specimens were immersed in Dulbecco's Modified Eagle's Medium, 31 and 9 specimens of which were treated with Er:YAG and Nd:YAG laser respectively. Untreated specimens served as controls. Incubation of specimens followed. Bioactivity was evaluated, using Fourier Transform Infrared spectroscopy (FTIR, Scanning Electron Microscopy (SEM/Energy Dispersive Spectroscopy (EDS and Transmission Electron Microscopy (TEM. FTIR detected peaks associated with hydroxyapatite on 1 Nd:YAG- and 4 Er:YAG-treated specimens. SEM analysis revealed that Er:YAG-treated specimens were covered by granular hydroxyapatite layer, while Nd:YAG treated specimen presented growth of flake-like hydroxyapatite. TEM confirmed the results. The untreated controls presented delayed bioactivity. In conclusion, Nd:YAG and Er:YAG laser treatment of the material, under certain fluencies, accelerates hydroxyapatite formation. Nd:YAG laser treatment of specific parameters causes the precipitation of flake-like hydroxyapatite in nano-scale.

  9. Synthesis and Characterization of Nano-Hydroxyapatite/mPEG-b-PCL Composite Coating on Nitinol Alloy

    OpenAIRE

    Mohamadreza Etminanfar; Jafar Khalil-Allafi; Kiyumars Jalili

    2017-01-01

    In this study the bioactivity of hydroxyapatite/poly(ε-caprolactone)–poly(ethylene glycol) bilayer coatings on Nitinol superelastic alloy was investigated. The surface of Nitinol alloy was activated by a thermo-chemical treatment and hydroxyapatite coating was electrodeposited on the alloy, followed by applying the polymer coating. The surface morphology of coatings was studied using FE-SEM and SEM. The data revealed that the hydroxyapatite coating is composed of one-dimensional nano sized fl...

  10. Engineered chitosan based nanomaterials: Bioactivities, mechanisms and perspectives in plant protection and growth.

    Science.gov (United States)

    Kumaraswamy, R V; Kumari, Sarita; Choudhary, Ram Chandra; Pal, Ajay; Raliya, Ramesh; Biswas, Pratim; Saharan, Vinod

    2018-07-01

    Excessive use of agrochemicals for enhancing crop production and its protection posed environmental and health concern. Integration of advanced technology is required to realize the concept of precision agriculture by minimizing the input of pesticides and fertilizers per unit while improving the crop productivity. Notably, chitosan based biodegradable nanomaterials (NMs) including nanoparticles, nanogels and nanocomposites have eventually proceeded as a key choice in agriculture due to their inimitable properties like antimicrobial and plant growth promoting activities. The foreseeable role of chitosan based NMs in plants might be in achieving sustainable plant growth through boosting the intrinsic potential of plants. In-spite of the fact that chitosan based NMs abode immense biological activities in plants, these materials have not yet been widely adopted in agriculture due to poor understanding of their bioactivity and modes of action towards pathogenic microbes and in plant protection and growth. To expedite the anticipated claims of chitosan based NMs, it is imperative to line up all the possible bioactivities which denote for sustainable agriculture. Herein, we have highlighted, in-depth, various chitosan based NMs which have been used in plant growth and protection mainly against fungi, bacteria and viruses and have also explained their modes of action. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Based on a new support for synthesis of highly efficient palladium/hydroxyapatite catalyst for ethanol electrooxidation

    International Nuclear Information System (INIS)

    Cui, Qian; Chao, Shujun; Bai, Zhengyu; Yan, Huiying; Wang, Kui; Yang, Lin

    2014-01-01

    Based on a new support, hydroxyapatite (HAP), a facile and low–cost preparation of palladium/hydroxyapatite catalyst for ethanol electrooxidation is introduced in this paper through a solvothermal reaction without additives. HAP was employed as the catalyst support for its hydroxyl–rich surface in order to increase the stability and utilization ratio of catalyst. According to transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and X–ray diffraction (XRD) measurements, the as–prepared Pd nanoparticles with face–centered cubic crystal structure were evenly deposited on the surface of HAP. Cyclic voltammetry and chronoamperometry tests demonstrated that the Pd/HAP catalyst possessed a much higher current density (246 mA cm −2 ) than the Pd/C catalyst (109 mA cm −2 ) towards ethanol electrooxidation, and better stability as well. In the direct ethanol fuel cell (DEFC) test, Pd/HAP catalyst gives better performance than that with Pd/C in terms of both open-circuit voltage (OCV) and power density. These results indicate that the HAP is a better support and the catalyst developed in this study may be a better candidate for DEFCs. A possible mechanism consistent with the experimental is also proposed

  12. Bactericidal strontium-releasing injectable bone cements based on bioactive glasses

    OpenAIRE

    Brauer, Delia S.; Karpukhina, Natalia; Kedia, Gopal; Bhat, Aditya; Law, Robert V.; Radecka, Izabela; Hill, Robert G.

    2013-01-01

    Strontium-releasing injectable bone cements may have the potential to prevent implant-related infections through the bactericidal action of strontium, while enhancing bone formation in patients suffering from osteoporosis. A melt-derived bioactive glass (BG) series (SiO2–CaO–CaF2–MgO) with 0–50% of calcium substituted with strontium on a molar base were produced. By mixing glass powder, poly(acrylic acid) and water, cements were obtained which can be delivered by injection and set in situ, gi...

  13. Enhanced Bioactivity of α-Tocopheryl Succinate Based Block Copolymer Nanoparticles by Reduced Hydrophobicity.

    Science.gov (United States)

    Palao-Suay, Raquel; Aguilar, María Rosa; Parra-Ruiz, Francisco J; Maji, Samarendra; Hoogenboom, Richard; Rohner, Nathan A; Thomas, Susan N; Román, Julio San

    2016-12-01

    Well-structured amphiphilic copolymers are necessary to obtain self-assembled nanoparticles (NPs) based on synthetic polymers. Highly homogeneous and monodispersed macromolecules obtained by controlled polymerization have successfully been used for this purpose. However, disaggregation of the organized macromolecules is desired when a bioactive element, such as α-tocopheryl succinate, is introduced in self-assembled NPs and this element must be exposed or released to exert its action. The aim of this work is to demonstrate that the bioactivity of synthetic NPs based on defined reversible addition-fragmentation chain transfer polymerization copolymers can be enhanced by the introduction of hydrophilic comonomers in the hydrophobic segment. The amphiphilic terpolymers are based on poly(ethylene glycol) (PEG) as hydrophilic block, and a hydrophobic block based on a methacrylic derivative of α-tocopheryl succinate (MTOS) and small amounts of 2-hydroxyethyl methacrylate (HEMA) (PEG-b-poly(MTOS-co-HEMA)). The introduction of HEMA reduces hydrophobicity and introduces "disorder" both in the homogeneous blocks and the compact core of the corresponding NPs. These NPs are able to encapsulate additional α-tocopheryl succinate (α-TOS) with high efficiency and their biological activity is much higher than that described for the unmodified copolymers, proposedly due to more efficient degradation and release of α-TOS, demonstrating the importance of the hydrophilic-hydrophobic balance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Histological evaluation of tissue reactions to newly synthetized calcium silicate- and hydroxyapatite-based bioactive materials: in vivo study

    Directory of Open Access Journals (Sweden)

    Opačić-Galić Vanja

    2017-01-01

    Full Text Available Introduction/Objective. Development of materials which could be used as biological bone substitutes is one of the most valuable and active fields of biomaterial research. The goal of the study was to research the reaction of tissue on calcium silicate- (CS and hydroxyapatitebased (CS-HA newly synthesized nanomaterials, after being implanted into the subcutaneous tissue of a rats and direct pulp capping of rabbit teeth. Methods. The tested materials were implanted in 40 Wistar male rats, sacrificed after seven, 15, 30, and 60 days. The direct pulp capping was performed on the teeth of rabbits. Cavities were prepared on the vestibular surface of the incisors. The animals were sacrificed after 10 and 15 days. The control material was mineral trioxide aggregate (MTA. Histological analysis covered the tracking of inflammatory reaction cellular components, presence of gigantic cells, and necrosis of the tissue. Results. Seven days after the implantation, the strongest inflammatory response was given by the MTA (3.3 Ѓ} 0.48, while CS and CS-HA scored 3 ± 0.71. After 60 days, the rate of inflammatory reactions dropped, which was the least visible with CS-HA (0.2 ± 0.45. The least visible inflammatory reaction of the rabbits’ pulp tissue was spotted with the CS (1.83 ± 0.75, than with the MTA and CS-HA (2.67 ± 1.53, 3 ± 0.63. Conclusion. The newly synthesized materials caused a slight reaction of the subcutaneous tissue. CS-HA showed the best tissue tolerance. Nanostructural biomaterials caused a slight to moderate inflammatory reaction of the rabbits’ pulp tissue only in the immediate vicinity of the implanted material.

  15. GEPSI: A Gene Expression Profile Similarity-Based Identification Method of Bioactive Components in Traditional Chinese Medicine Formula.

    Science.gov (United States)

    Zhang, Baixia; He, Shuaibing; Lv, Chenyang; Zhang, Yanling; Wang, Yun

    2018-01-01

    The identification of bioactive components in traditional Chinese medicine (TCM) is an important part of the TCM material foundation research. Recently, molecular docking technology has been extensively used for the identification of TCM bioactive components. However, target proteins that are used in molecular docking may not be the actual TCM target. For this reason, the bioactive components would likely be omitted or incorrect. To address this problem, this study proposed the GEPSI method that identified the target proteins of TCM based on the similarity of gene expression profiles. The similarity of the gene expression profiles affected by TCM and small molecular drugs was calculated. The pharmacological action of TCM may be similar to that of small molecule drugs that have a high similarity score. Indeed, the target proteins of the small molecule drugs could be considered TCM targets. Thus, we identified the bioactive components of a TCM by molecular docking and verified the reliability of this method by a literature investigation. Using the target proteins that TCM actually affected as targets, the identification of the bioactive components was more accurate. This study provides a fast and effective method for the identification of TCM bioactive components.

  16. Characterization of hydroxyapatite substituted with silicon

    International Nuclear Information System (INIS)

    Silva, H.M. da; Soares, G.A.; Mateescu, M.; Anselme, K.; Palard, M.; Champion, E.

    2009-01-01

    Incorporation of silicon (Si) ions into hydroxyapatite structure (HA) influences on physical, chemical and physiological properties. Some studies reported the improved bioactivity Si substitution, and it also accelerates the biomineralization process. The main objective of this work is to characterize stoichiometric hydroxyapatite and hydroxyapatite substituted with 1.13% in weight of Si (SiHA) using a wet precipitation method followed by a heat treatment. SEM/EDS, AFM, DRX and FTIR analyses were used to characterize the samples. EDS and FTIR results confirmed the presence of Si. Silicon induces small changes on crystal structure of HA, not detected on X-ray diffraction patterns of sintered tablets of SiHA and HA. No secondary phases were observed, that indicates the Si had entered the HA lattice. (author)

  17. Improved surface bioactivity of stainless steel substrates using osteocalcin mimetic peptide

    International Nuclear Information System (INIS)

    Hosseini, Samaneh; Naderi-Manesh, Hossein; Vali, Hojatollah; Faghihi, Shahab

    2014-01-01

    Although stainless steel has a good biocompatibility for most clinical cases, the higher tissue response (bone bonding property) is required in orthopedic field. In this study, to improve bone-bonding ability of stainless steel substrates, a specific sequence of osteocalcin mimetic peptide is used as bioactive coating material to biochemically modify the surface of metallic samples. This sequence consists of thirteen amino acids present in the first helix of osteocalcin is synthesized in amidic form and physically adsorbed on the surface of 316LS (316 low carbon surgical grade) stainless steel substrates. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to characterize the surface of peptide coated and uncoated substrates. The bioactivity and bone bonding ability of coated and uncoated substrates are assessed by level of hydroxyapatite formation, using transmission electron microscopy (TEM), energy-dispersive x-ray (EDS), and scanning electron microscopy (SEM). The pre-osteoblast cell attachment and proliferation are also evaluated by MTT assay. The results show that the surface of coated sample is homogenously covered by the peptide and display a rougher surface relative to uncoated sample. TEM images reveal the formation of plate-like hydroxyapatite crystals in the presence of the peptide and an amorphous calcium phosphate phase without the peptide. Pre-osteoblast cells proliferation is significantly higher on the surface of peptide coated substrate, while cell attachment remains unaffected by the peptide coatings. Pre-osteoblast cells also demonstrate a higher degree of spreading on the surface of coated sample. It is believed that osteocalcin mimetic peptide improve surface bioactivity and promote hydroxyapatite crystal formation may lead to increased mineralization and bone formation on the surface of metallic biomedical devices. - Graphical abstract: A peptide sequence located in the first helix of OC is selected based on its

  18. Improved surface bioactivity of stainless steel substrates using osteocalcin mimetic peptide

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, Samaneh [Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Tissue Engineering and Biomaterials Division, National Institute of Genetic Engineering and Biotechnology, Tehran 14965/161 (Iran, Islamic Republic of); Naderi-Manesh, Hossein, E-mail: naderman@modares.ac.ir [Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Vali, Hojatollah [Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montréal, QC H3A 0C7 (Canada); Faghihi, Shahab, E-mail: sfaghihi@nigeb.ac.ir [Tissue Engineering and Biomaterials Division, National Institute of Genetic Engineering and Biotechnology, Tehran 14965/161 (Iran, Islamic Republic of)

    2014-02-14

    Although stainless steel has a good biocompatibility for most clinical cases, the higher tissue response (bone bonding property) is required in orthopedic field. In this study, to improve bone-bonding ability of stainless steel substrates, a specific sequence of osteocalcin mimetic peptide is used as bioactive coating material to biochemically modify the surface of metallic samples. This sequence consists of thirteen amino acids present in the first helix of osteocalcin is synthesized in amidic form and physically adsorbed on the surface of 316LS (316 low carbon surgical grade) stainless steel substrates. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to characterize the surface of peptide coated and uncoated substrates. The bioactivity and bone bonding ability of coated and uncoated substrates are assessed by level of hydroxyapatite formation, using transmission electron microscopy (TEM), energy-dispersive x-ray (EDS), and scanning electron microscopy (SEM). The pre-osteoblast cell attachment and proliferation are also evaluated by MTT assay. The results show that the surface of coated sample is homogenously covered by the peptide and display a rougher surface relative to uncoated sample. TEM images reveal the formation of plate-like hydroxyapatite crystals in the presence of the peptide and an amorphous calcium phosphate phase without the peptide. Pre-osteoblast cells proliferation is significantly higher on the surface of peptide coated substrate, while cell attachment remains unaffected by the peptide coatings. Pre-osteoblast cells also demonstrate a higher degree of spreading on the surface of coated sample. It is believed that osteocalcin mimetic peptide improve surface bioactivity and promote hydroxyapatite crystal formation may lead to increased mineralization and bone formation on the surface of metallic biomedical devices. - Graphical abstract: A peptide sequence located in the first helix of OC is selected based on its

  19. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility.

    Science.gov (United States)

    Verné, Enrica; Bruno, Matteo; Miola, Marta; Maina, Giovanni; Bianco, Carlotta; Cochis, Andrea; Rimondini, Lia

    2015-08-01

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO2-Na2O-CaO-P2O5-FeO-Fe2O3 and contains magnetite (Fe3O4) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite - HAp - layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Development of bioactive coatings based on γ-irradiated proteins to preserve strawberries

    International Nuclear Information System (INIS)

    Vu, K.D.; Hollingsworth, R.G.; Salmieri, S.; Takala, P.N.; Lacroix, M.

    2012-01-01

    Gamma irradiation was applied for creating cross-linked proteins to enhance the physicochemical properties of edible films made of calcium caseinate, whey protein isolate and glycerol. The characteristics of γ irradiated cross-linked proteins were analyzed by Fourier Transform Infrared spectroscopy. A second derivative spectra exhibited changes in band intensities that were correlated to an increase of β-sheet structure and a decrease of α-helix and unordered fractions of γ irradiated-cross-linked proteins as compared to the control without irradiation. Furthermore, on addition of methylcellulose to the irradiated protein matrix it was found that it has potential in enhancing the puncture strength and has no detrimental effect on water vapor permeability of protein based films. Finally, these film formulations were used as bioactive edible coatings containing natural antimicrobial agents (limonene and peppermint) to preserve the shelf life of fresh strawberries during storage. The bioactive coatings containing peppermint was found to be more efficient as preserving coatings than the formulations containing limonene. Irradiated proteins/methylcellulose/peppermint formulation had only 40% of decay at day 8 while it was 65% for the control. - Highlights: ► Crosslinked proteins and antimicrobials agents was able to preserve strawberries. ► Crosslinked protein structure was more ordered. ► Films based on crosslinked proteins and methylcellulose enhanced puncture strength.

  1. XPS and XANES studies of biomimetic composites based on B-type nano-hydroxyapatite

    Science.gov (United States)

    Goloshchapov, D. L.; Gushchin, M. S.; Kashkarov, V. M.; Seredin, P. V.; Ippolitov, Y. A.; Khmelevsky, N. O.; Aksenenko, A. Yu.

    2018-06-01

    The paper presents an investigation of the local atomic structure of nanocrystalline carbonate-substituted hydroxyapatite (CHAP) contained in biomimetic composites - analogues of intact human tooth tissues. Using the XPS technique, the presence of impurity Mg and F atoms and structurally bound carbon in CHAP, at the concentrations typical of apatite enamel and dentine was determined. The XANES method was used to study the changes occurring in P L2,3 spectra of biocomposites with CHAP, depending on the percentage of the amino acid matrix. The appearance of maxima in the spectra of XANES P L2,3 near 135.7 eV for the samples with the composition of amino acid complex/hydroxyapatite - 5/95, 25/75 and the splitting of a broad peak of 146.9 eV in the spectrum of a biocomposite with a composition of 40/60 indicates at the interaction of molecular complex of amino acids with atomic environment of phosphorus. This fact can be used in the fundamental medicine for synthesizing of new biomaterials in dentistry.

  2. Synthesis and characterization of irradiated injectable bone substitute paste based on hydroxyapatite

    International Nuclear Information System (INIS)

    Yessy Warastuti; Basril Abbas

    2011-01-01

    Synthesis and characterization of hydroxyapatite, chitosan and hydroxypropyl methylcellulose (HPMC) composite in injectable paste form have been done. The composite was synthesized by stirring hydroxyapatite, chitosan and HPMC until homogen. IBS paste was irradiated at the dose of 25 kGy (sterile dose). Characterization of IBS paste was conducted by measuring of the water content, identification of functional group with Fourier Transform Infra Red Spectrophotometer (FTIR), and identification of sample morphology with Scanning Electron Microscope Energy Dispersive Spectrophotometer (SEM EDS). The result showed that the water content of irradiated sample was higher than unirradiated sample due to water radiolysis. Several specific bands of IBS paste were identified, i.e., carbonate (CO 3 2- ), at 1420 cm -1 , phosphate (PO 4 3- ) at 1043 cm -1 , 605 cm -1 , 568 cm -1 and chitosan (NH 2 ) at 1599 cm -1 . There is no significant difference in absorbed band between irradiated and unirradiated samples. IBS paste has a microstructure with the size of 0.05 – 0.1 μm. Electron beam irradiation did not change the structure and morphology of sample. (author)

  3. Bioactive substances

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.

    Chemistry related to certain bioactive molecules, from Indian Ocean Region, developed into drugs or which served as models for the synthesis of more effective bioactive substances or in use in fundamental studies of physiological and biochemical...

  4. Antimicrobial thin films based on ayurvedic plants extracts embedded in a bioactive glass matrix

    Science.gov (United States)

    Floroian, L.; Ristoscu, C.; Candiani, G.; Pastori, N.; Moscatelli, M.; Mihailescu, N.; Negut, I.; Badea, M.; Gilca, M.; Chiesa, R.; Mihailescu, I. N.

    2017-09-01

    Ayurvedic medicine is one of the oldest medical systems. It is an example of a coherent traditional system which has a time-tested and precise algorithm for medicinal plant selection, based on several ethnopharmacophore descriptors which knowledge endows the user to adequately choose the optimal plant for the treatment of certain pathology. This work aims for linking traditional knowledge with biomedical science by using traditional ayurvedic plants extracts with antimicrobial effect in form of thin films for implant protection. We report on the transfer of novel composites from bioactive glass mixed with antimicrobial plants extracts and polymer by matrix-assisted pulsed laser evaporation into uniform thin layers onto stainless steel implant-like surfaces. The comprehensive characterization of the deposited films was performed by complementary analyses: Fourier transformed infrared spectroscopy, glow discharge optical emission spectroscopy, scanning electron microscopy, atomic force microscopy, electrochemical impedance spectroscopy, UV-VIS absorption spectroscopy and antimicrobial tests. The results emphasize upon the multifunctionality of these coatings which allow to halt the leakage of metal and metal oxides into the biological fluids and eventually to inner organs (by polymer use), to speed up the osseointegration (due to the bioactive glass use), to exert antimicrobial effects (by ayurvedic plants extracts use) and to decrease the implant price (by cheaper stainless steel use).

  5. Clinical and radiographic evaluation of citric acid-based nano hydroxyapatite composite graft in the regeneration of intrabony defects - A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Chaurasia Priya Dayashankar

    2017-01-01

    Full Text Available Background: Conventional periodontal therapy with various bone grafts has limited scope and the results are not predictable. To improve their utility, the hybridization of bioceramics and biodegradable polymers has been widely adopted to reform the mechanical properties of bone grafts. One such biodegradable polymer is POC (Poly 1,8 octanediol. Secondly, citric acid is considered as the key material in bone mineralization, which is related to the overall stability, strength and fracture resistance of bone. Hence citric acid is incorporated in a polymer and Nano hydroxyapatite to form a composite graft, for periodontal bone regeneration. This study attempts to evaluate the efficacy of citric acid based Nano-hydroxyapatite composite graft for the treatment of intrabony defects in chronic periodontitis patients over 12 months. Methods: A split mouth study, which consists of 10 systemically healthy patients, were randomly treated with Citric acid based Nano hydroxyapatite composite graft (test sites, n=18 or with Nano hydroxyapatite alone (control sites, n=15. Plaque index, gingival index, gingival bleeding index, probing pocket depth (PPD, clinical attachment level (CAL, bone probing depth (BPD and hard tissue parameters such as amount of defect fill, percentage of defect fill, and changes in alveolar crest were assessed over a period of 12 months. Statistical analysis used was student's t-test and One-Way ANOVA. Results: Both test and control sites demonstrated statistically significant reduction of PD, BPD, gain in CAL and radiographic bone fill. Nevertheless the test sites showed Statistically significant improvements in all the parameters as compared to control sites at 12 months. Conclusion: Citric acid based Nano hydroxyapatite composite graft can be considered as a newer material for periodontal regeneration.

  6. Graphene oxide/oxidized carbon nanofiber/mineralized hydroxyapatite based hybrid composite for biomedical applications

    Science.gov (United States)

    Murugan, N.; Sundaramurthy, Anandhakumar; Chen, Shen-Ming; Sundramoorthy, Ashok K.

    2017-12-01

    Hydroxyapatite (Ca10(PO4)6(OH)2, HAP), a multi-mineral substituted calcium phosphate is the main mineral component of tooth enamel and bone, has become an important biomaterial for biomedical applications. However, as-synthesized HAP has poor mechanical properties and inferior wear resistance, so it is not suitable to use in bone tissue engineering applications. We report the successful incorporation of oxidized carbon nanofibers (O-CNF) and graphene oxide (GO) into the mineralized hydroxyapatite (M-HAP) which showed excellent mechanical and biological properties. GO improved the high mechanical strength and corrosion protection of the substrate in simulated body fluid (SBF) solution and promoted the viability of osteoblasts MG63 cells. As-prepared M-HAP/O-CNF/GO composite showed materials characteristics that similar to natural bone (M-HAP) with high mechanical strength. The resultant M-HAP/O-CNF/GO composite was characterized out by x-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR), respectively. The mechanical strength of the material was determined by Vicker’s micro-hardness method and it was found that M-HAP/O-CNF/GO (468  ±  4 Hv) composite has superior mechanical properties than M-HAP (330  ±  3 Hv) and M-HAP/GO (425  ±  5 Hv) samples. In addition, antibacterial activity of the composite was studied against Staphylococcus aureus and Escherichia coli. Furthermore, the cell viability of the composite was observed in vitro against osteoblast cells. All these studies confirmed that the M-HAP/O-CNF/GO composite can be considered as potential candidate for dental and orthopedic applications.

  7. Sol-gel derived porous bioactive nanocomposites: Synthesis and in vitro bioactivity

    Science.gov (United States)

    Shankhwar, Nisha; Kothiyal, G. P.; Srinivasan, A.

    2013-06-01

    Porous bioactive composites consisting of SiO2-CaO-Na2O-P2O5 bioactive glass-ceramic and synthetic water soluble polymer Polyvinylpyrrolidone [PVP (C6H9NO)n, MW˜40000 g/mol] have been synthesized by sol-gel route. As-prepared polymeric composites were characterized by X-ray diffraction (XRD) technique. Two major bone mineral phases, viz., hydroxyapatite [Ca10(PO4)6(OH)2] and wollastonite [calcium silicate (CaSiO3)] have been identified in the XRD patterns of the composites. Presence of these bone minerals indicates the bioactive nature of the composites. In vitro bioactivity tests confirm bioactivity in the porous composites. The flexibility offered by these bioactive polymer composites is advantageous for its application as implant material.

  8. EuroFIR-BASIS - a combined composition and biological activity database for bioactive compounds in plant-based foods

    DEFF Research Database (Denmark)

    Gry, Jørn; Black, Lucinda; Eriksen, Folmer Damsted

    2007-01-01

    Mounting evidence suggests that certain non-nutrient bioactive compounds promote optimal human health and reduce the risk of chronic disease. An Internet-deployed database, EuroFIR-BASIS, which uniquely combines food composition and biological effects data for plant-based bioactive compounds......, is being developed. The database covers multiple compound classes and 330 major food plants and their edible parts with data sourced from quality-assessed, peer-reviewed literature. The database will be a valuable resource for food regulatory and advisory bodies, risk authorities, epidemiologists...... and researchers interested in diet and health relationships, and product developers within the food industry....

  9. Synthesis of Ca,Y-zirconia/hydroxyapatite nanoparticles and composites

    Czech Academy of Sciences Publication Activity Database

    Částková, K.; Hadraba, Hynek; Matoušek, A.; Roupcová, P.; Chlup, Zdeněk; Novotná, L.; Cihlář, J.

    2016-01-01

    Roč. 36, č. 12 (2016), s. 2903-2912 ISSN 0955-2219 R&D Projects: GA ČR GA14-11234S; GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : Zirconia * Hydroxyapatite * Composite * Bioactivity * Mechanical properties Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass Impact factor: 3.411, year: 2016

  10. Bio-Activity and Dereplication-Based Discovery of Ophiobolins and Other Fungal Secondary Metabolites Targeting Leukemia Cells

    DEFF Research Database (Denmark)

    Bladt, Tanja Thorskov; Dürr, Claudia; Knudsen, Peter Boldsen

    2013-01-01

    The purpose of this study was to identify and characterize fungal natural products (NPs) with in vitro bioactivity towards leukemia cells. We based our screening on a combined analytical and bio-guided approach of LC-DAD-HRMS dereplication, explorative solid-phase extraction (E-SPE), and a co...

  11. Hydroxyapatite scaffolds processed using a TBA-based freeze-gel casting/polymer sponge technique.

    Science.gov (United States)

    Yang, Tae Young; Lee, Jung Min; Yoon, Seog Young; Park, Hong Chae

    2010-05-01

    A novel freeze-gel casting/polymer sponge technique has been introduced to fabricate porous hydroxyapatite scaffolds with controlled "designer" pore structures and improved compressive strength for bone tissue engineering applications. Tertiary-butyl alcohol (TBA) was used as a solvent in this work. The merits of each production process, freeze casting, gel casting, and polymer sponge route were characterized by the sintered microstructure and mechanical strength. A reticulated structure with large pore size of 180-360 microm, which formed on burn-out of polyurethane foam, consisted of the strut with highly interconnected, unidirectional, long pore channels (approximately 4.5 microm in dia.) by evaporation of frozen TBA produced in freeze casting together with the dense inner walls with a few, isolated fine pores (<2 microm) by gel casting. The sintered porosity and pore size generally behaved in an opposite manner to the solid loading, i.e., a high solid loading gave low porosity and small pore size, and a thickening of the strut cross section, thus leading to higher compressive strengths.

  12. Fabrication of novel biodegradable porous bone scaffolds based on amphiphilic hydroxyapatite nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xiaoyan; Hui, Junfeng [Shaanxi Key Laboratory of Degradable Biomedical Materials, Shaanxi R& D Center of Biomaterials and Fermentation Engineering, School of Chemical and Engineering, Northwest University, Xi' an 710069, Shaanxi, PR China2 (China); Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an 710069, Shaanxi (China); Li, Hui; Zhu, Chenhui [Shaanxi Key Laboratory of Degradable Biomedical Materials, Shaanxi R& D Center of Biomaterials and Fermentation Engineering, School of Chemical and Engineering, Northwest University, Xi' an 710069, Shaanxi, PR China2 (China); Hua, Xiufu, E-mail: hua_xiufu@163.com [Department of Scientific Research and Development, Tsinghua University, Beijing 100084 (China); Ma, Haixia, E-mail: mahx@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an 710069, Shaanxi (China); Fan, Daidi, E-mail: fandaidi@nwu.edu.cn [Shaanxi Key Laboratory of Degradable Biomedical Materials, Shaanxi R& D Center of Biomaterials and Fermentation Engineering, School of Chemical and Engineering, Northwest University, Xi' an 710069, Shaanxi, PR China2 (China)

    2017-06-01

    This paper describes a new synthetic strategy and biological application for novel amphiphilic hydroxyapatite (HAp) nanorods. The prepared HAp nanorods were able to be dispersed in water, ethyl alcohol and cyclohexane. The co-anchoring of the multidentate ligands of PEG 20000 and hydrophobic oleic acid (OA) on the rods' surfaces endowed them with excellent amphibious properties. Utilizing amphiphilic HAp nanorods with excellent biocompatibility as the inorganic phase, human-like collagen (HLC) as the organic phase and natural genipin as the cross-linker, optimal HLC/HAp porous scaffolds (HLC: HAp = 1:4, w/w) were fabricated. The compression stress and three-point bending strength of the scaffolds with pore diameters of 150 to 200 μm reached approximately 3.4 MPa and 5.4 MPa, respectively, and their porosity was 77.35 ± 3.75%. Cytological tests showed that HLC/HAp scaffolds could contribute to cell proliferation and differentiation. The results indicated that these novel amphiphilic HAp nanorods can be expected to become recognized as an excellent inorganic material for the porous scaffolds used in repairing bone and related applications. - Highlights: • A simple and effective hydrothermal method was developed for preparing uniform HAp nanorods with amphiphilic surfaces. • The synthesized amphiphilic HAp nanorods could be dispersed in water, ethyl alcohol or cyclohexane. • The prepared HLC/HAp porous scaffolds had good mechanical properties, biocompatibility and osteoconductive etc.

  13. Fabrication of novel biodegradable porous bone scaffolds based on amphiphilic hydroxyapatite nanorods

    International Nuclear Information System (INIS)

    Zheng, Xiaoyan; Hui, Junfeng; Li, Hui; Zhu, Chenhui; Hua, Xiufu; Ma, Haixia; Fan, Daidi

    2017-01-01

    This paper describes a new synthetic strategy and biological application for novel amphiphilic hydroxyapatite (HAp) nanorods. The prepared HAp nanorods were able to be dispersed in water, ethyl alcohol and cyclohexane. The co-anchoring of the multidentate ligands of PEG 20000 and hydrophobic oleic acid (OA) on the rods' surfaces endowed them with excellent amphibious properties. Utilizing amphiphilic HAp nanorods with excellent biocompatibility as the inorganic phase, human-like collagen (HLC) as the organic phase and natural genipin as the cross-linker, optimal HLC/HAp porous scaffolds (HLC: HAp = 1:4, w/w) were fabricated. The compression stress and three-point bending strength of the scaffolds with pore diameters of 150 to 200 μm reached approximately 3.4 MPa and 5.4 MPa, respectively, and their porosity was 77.35 ± 3.75%. Cytological tests showed that HLC/HAp scaffolds could contribute to cell proliferation and differentiation. The results indicated that these novel amphiphilic HAp nanorods can be expected to become recognized as an excellent inorganic material for the porous scaffolds used in repairing bone and related applications. - Highlights: • A simple and effective hydrothermal method was developed for preparing uniform HAp nanorods with amphiphilic surfaces. • The synthesized amphiphilic HAp nanorods could be dispersed in water, ethyl alcohol or cyclohexane. • The prepared HLC/HAp porous scaffolds had good mechanical properties, biocompatibility and osteoconductive etc.

  14. Multifunctional nano-hydroxyapatite and alginate/gelatin based sticky gel composites for potential bone regeneration

    International Nuclear Information System (INIS)

    Cai, Yurong; Yu, Juhong; Kundu, Subhas C.; Yao, Juming

    2016-01-01

    To improve the fixations of the implant and implant-bone integration after joint arthroplasty from locally preventing inflammation and promoting the bone regeneration, we design a multifunctional biomaterial consisting of recombinant human bone morphogenetic protein 2 (rhBMP-2) and antibiotic loaded nano-hydroxyapatite with an alginate/gelatin sticky gel. We investigate its role for the prevention of the inflammation and possibility of inducing a new bone growth along with its adhesive ability. The stickiness exists in the composite, which may help to fix itself on the bone fracture surface. The composite sustains the antibacterial effect and promotes the proliferation and differentiation of MG63 cells in vitro. In vivo experimentation also shows that the composite gel has a role for the reduction of inflammation. It enhances the formation of new bone and blood vessels compared to both the sole rhBMP-2 and non-rhBMP-2/antibiotic loaded composite gels. The multifunctional composite provides a promising material for the prosthetic and bone tissue regeneration. - Highlights: • Multifunctional nanohydroxyapatite composite is fabricated. • The composite consists of nHAP, growth factor, antibiotic and alginate/gelatin gel. • The composite shows antibacterial effect and good cytocompatibility. • No adverse effect to the cells tested in vitro and in vivo.

  15. Hybrid Mesoporous Silica-Based Drug Carrier Nanostructures with Improved Degradability by Hydroxyapatite.

    Science.gov (United States)

    Hao, Xiaohong; Hu, Xixue; Zhang, Cuimiao; Chen, Shizhu; Li, Zhenhua; Yang, Xinjian; Liu, Huifang; Jia, Guang; Liu, Dandan; Ge, Kun; Liang, Xing-Jie; Zhang, Jinchao

    2015-10-27

    Potential bioaccumulation is one of the biggest limitations for silica nanodrug delivery systems in cancer therapy. In this study, a mesoporous silica nanoparticles/hydroxyapatite (MSNs/HAP) hybrid drug carrier, which enhanced the biodegradability of silica, was developed by a one-step method. The morphology and structure of the nanoparticles were characterized by TEM, DLS, FT-IR, XRD, N2 adsorption-desorption isotherms, and XPS, and the drug loading and release behaviors were tested. TEM and ICP-OES results indicate that the degradability of the nanoparticles has been significantly improved by Ca(2+) escape from the skeleton in an acid environment. The MSNs/HAP sample exhibits a higher drug loading content of about 5 times that of MSNs. The biological experiment results show that the MSNs/HAP not only exhibits good biocompatibility and antitumor effect but also greatly reduces the side effects of free DOX. The as-synthesized hybrid nanoparticles may act as a promising drug delivery system due to their good biocompatibility, high drug loading efficiency, pH sensitivity, and excellent biodegradability.

  16. Multifunctional nano-hydroxyapatite and alginate/gelatin based sticky gel composites for potential bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yurong; Yu, Juhong [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab of Textile Fiber Materials & Processing Technology, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Kundu, Subhas C. [Department of Biotechnology, Indian Institute of Technology (IIT) Kharagpur, West Bengal 721302 (India); Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 330-714 (Korea, Republic of); Yao, Juming, E-mail: yaoj@zstu.edu.cn [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab of Textile Fiber Materials & Processing Technology, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2016-09-15

    To improve the fixations of the implant and implant-bone integration after joint arthroplasty from locally preventing inflammation and promoting the bone regeneration, we design a multifunctional biomaterial consisting of recombinant human bone morphogenetic protein 2 (rhBMP-2) and antibiotic loaded nano-hydroxyapatite with an alginate/gelatin sticky gel. We investigate its role for the prevention of the inflammation and possibility of inducing a new bone growth along with its adhesive ability. The stickiness exists in the composite, which may help to fix itself on the bone fracture surface. The composite sustains the antibacterial effect and promotes the proliferation and differentiation of MG63 cells in vitro. In vivo experimentation also shows that the composite gel has a role for the reduction of inflammation. It enhances the formation of new bone and blood vessels compared to both the sole rhBMP-2 and non-rhBMP-2/antibiotic loaded composite gels. The multifunctional composite provides a promising material for the prosthetic and bone tissue regeneration. - Highlights: • Multifunctional nanohydroxyapatite composite is fabricated. • The composite consists of nHAP, growth factor, antibiotic and alginate/gelatin gel. • The composite shows antibacterial effect and good cytocompatibility. • No adverse effect to the cells tested in vitro and in vivo.

  17. Hydroxyapatite-Coated Magnesium-Based Biodegradable Alloy: Cold Spray Deposition and Simulated Body Fluid Studies

    Science.gov (United States)

    Noorakma, Abdullah C. W.; Zuhailawati, Hussain; Aishvarya, V.; Dhindaw, B. K.

    2013-10-01

    A simple modified cold spray process in which the substrate of AZ51 alloys were preheated to 400 °C and sprayed with hydroxyapatite (HAP) using high pressure cold air nozzle spray was designed to get biocompatible coatings of the order of 20-30 μm thickness. The coatings had an average modulus of 9 GPa. The biodegradation behavior of HAP-coated samples was tested by studying with simulated body fluid (SBF). The coating was characterized by FESEM microanalysis. ICPOES analysis was carried out for the SBF solution to know the change in ion concentrations. Control samples showed no aluminum corrosion but heavy Mg corrosion. On the HAP-coated alloy samples, HAP coatings started dissolving after 1 day but showed signs of regeneration after 10 days of holding. All through the testing period while the HAP coating got eroded, the surface of the sample got deposited with different apatite-like compounds and the phase changed with course from DCPD to β-TCP and β-TCMP. The HAP-coated samples clearly improved the biodegradability of Mg alloy, attributed to the dissolution and re-precipitation of apatite showed by the coatings as compared to the control samples.

  18. The evaluation of hydroxyapatite (HA) coated and uncoated porous tantalum for biomedical material applications

    International Nuclear Information System (INIS)

    Safuan, Nadia; Sukmana, Irza; Kadir, Mohammed Rafiq Abdul; Noviana, Deni

    2014-01-01

    Porous tantalum has been used as an orthopedic implant for bone defects as it has a good corrosion resistance and fatigue behaviour properties. However, there are some reports on the rejection of porous Ta after the implantation. Those clinical cases refer to the less bioactivity of metallic-based materials. This study aims to evaluate hydroxyapatite coated and uncoated porous Tantalum in order to improve the biocompatibility of porous tantalum implant and osseointegration. Porous tantalum was used as metallic-base substrate and hydroxyapatite coating has been done using plasma-spraying technique. Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM) techniques were utilizes to investigate the coating characteristics while Confocal Raman Microscopy to investigate the interface and image. The effect of coating to the corrosion behaviour was assessed by employing potentiodynamic polarization tests in simulated body fluid at 37±1 °C. Based on SEM and FESEM results, the morphologies as well the weight element consists in the uncoated and hydroxyapatite coated porous tantalum were revealed. The results indicated that the decrease in corrosion current density for HA coated porous Ta compared to the uncoated porous Ta. This study concluded that by coating porous tantalum with HA supports to decrease the corrosion rate of pure porous.

  19. The Evaluation of Hydroxyapatite (HA) Coated and Uncoated Porous Tantalum for Biomedical Material Applications

    Science.gov (United States)

    Safuan, Nadia; Sukmana, Irza; Kadir, Mohammed Rafiq Abdul; Noviana, Deni

    2014-04-01

    Porous tantalum has been used as an orthopedic implant for bone defects as it has a good corrosion resistance and fatigue behaviour properties. However, there are some reports on the rejection of porous Ta after the implantation. Those clinical cases refer to the less bioactivity of metallic-based materials. This study aims to evaluate hydroxyapatite coated and uncoated porous Tantalum in order to improve the biocompatibility of porous tantalum implant and osseointegration. Porous tantalum was used as metallic-base substrate and hydroxyapatite coating has been done using plasma-spraying technique. Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM) techniques were utilizes to investigate the coating characteristics while Confocal Raman Microscopy to investigate the interface and image. The effect of coating to the corrosion behaviour was assessed by employing potentiodynamic polarization tests in simulated body fluid at 37±1 °C. Based on SEM and FESEM results, the morphologies as well the weight element consists in the uncoated and hydroxyapatite coated porous tantalum were revealed. The results indicated that the decrease in corrosion current density for HA coated porous Ta compared to the uncoated porous Ta. This study concluded that by coating porous tantalum with HA supports to decrease the corrosion rate of pure porous.

  20. Crystalline hydroxyapatite coatings synthesized under hydrothermal conditions on modified titanium substrates

    International Nuclear Information System (INIS)

    Suchanek, Katarzyna; Bartkowiak, Amanda; Gdowik, Agnieszka; Perzanowski, Marcin; Kąc, Sławomir; Szaraniec, Barbara; Suchanek, Mateusz; Marszałek, Marta

    2015-01-01

    Hydroxyapatite coatings were successfully produced on modified titanium substrates via hydrothermal synthesis in a Ca(EDTA) 2− and (NH 4 ) 2 HPO 4 solution. The morphology of modified titanium substrates as well as hydroxyapatite coatings was studied using scanning electron microcopy and phase identification by X-ray diffraction, and Raman and FTIR spectroscopy. The results show that the nucleation and growth of hydroxyapatite needle-like crystals with hexagonal symmetry occurred only on titanium substrates both chemically and thermally treated. No hydroxyapatite phase was detected on only acid etched Ti metal. This finding demonstrates that only a particular titanium surface treatment can effectively induce the apatite nucleation under hydrothermal conditions. - Highlights: • Bioactivation of titanium substrate by chemical and heat treatments • Precipitation of hydroxyapatite on modified titanium plates • Hydrothermal crystallization of hydroxyapatite by chelate decomposition method

  1. Crystalline hydroxyapatite coatings synthesized under hydrothermal conditions on modified titanium substrates

    Energy Technology Data Exchange (ETDEWEB)

    Suchanek, Katarzyna, E-mail: Katarzyna.Suchanek@ifj.edu.pl [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland); Bartkowiak, Amanda [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland); Gdowik, Agnieszka [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow (Poland); Perzanowski, Marcin [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland); Kąc, Sławomir [Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Mickiewica 30, 30-059 Krakow (Poland); Szaraniec, Barbara [Department of Biomaterials, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow (Poland); Suchanek, Mateusz [Department of Chemistry and Physics, University of Agriculture in Krakow, Mickiewicza 21, 31-120 Krakow (Poland); Marszałek, Marta [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland)

    2015-06-01

    Hydroxyapatite coatings were successfully produced on modified titanium substrates via hydrothermal synthesis in a Ca(EDTA){sup 2−} and (NH{sub 4}){sub 2}HPO{sub 4} solution. The morphology of modified titanium substrates as well as hydroxyapatite coatings was studied using scanning electron microcopy and phase identification by X-ray diffraction, and Raman and FTIR spectroscopy. The results show that the nucleation and growth of hydroxyapatite needle-like crystals with hexagonal symmetry occurred only on titanium substrates both chemically and thermally treated. No hydroxyapatite phase was detected on only acid etched Ti metal. This finding demonstrates that only a particular titanium surface treatment can effectively induce the apatite nucleation under hydrothermal conditions. - Highlights: • Bioactivation of titanium substrate by chemical and heat treatments • Precipitation of hydroxyapatite on modified titanium plates • Hydrothermal crystallization of hydroxyapatite by chelate decomposition method.

  2. Preparation, characterization and biological test of 3D-scaffolds based on chitosan, fibroin and hydroxyapatite for bone tissue engineering

    International Nuclear Information System (INIS)

    Lima, Paulo Autran Leite; Resende, Cristiane Xavier; Dulce de Almeida Soares, Glória; Anselme, Karine; Almeida, Luís Eduardo

    2013-01-01

    This work describes the preparation and characterization of porous 3D-scaffolds based on chitosan (CHI), chitosan/silk fibroin (CHI/SF) and chitosan/silk fibroin/hydroxyapatite (CHI/SF/HA) by freeze drying. The biomaterials were characterized by X-ray diffraction, attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy and energy dispersive spectroscopy. In addition, studies of porosity, pore size, contact angle and biological response of SaOs-2osteoblastic cells were performed. The CHI scaffolds have a porosity of 94.2 ± 0.9%, which is statistically higher than the one presented by CHI/SF/HA scaffolds, 89.7 ± 2.6%. Although all scaffolds were able to promote adhesion, growth and maintenance of osteogenic differentiation of SaOs-2 cells, the new 3D-scaffold based on CHI/SF/HA showed a significantly higher cell growth at 7 days and 21 days and the level of alkaline phosphatase at 14 and 21 days was statistically superior compared to other tested materials. - Highlights: • Preparation of 3D-scaffolds based on CHI, with or without addition of SF and HA. • Scaffolds exhibited interconnected porous structure (pore size superior to 50 μm). • The tripolyphosphate did not induce any significant cytotoxic response. • The CHI/SF/HA composite showed a higher cell growth and ALP activity

  3. Highly sensitive and selective detection of Bis-phenol A based on hydroxyapatite decorated reduced graphene oxide nanocomposites

    International Nuclear Information System (INIS)

    Alam, Mohammad K.; Rahman, Mohammed M.; Elzwawy, Amir; Torati, Sri Ramulu; Islam, Mohammad S.; Todo, Mitsugu; Asiri, Abdullah M.; Kim, Dojin; Kim, CheolGi

    2017-01-01

    Highlights: •Simple chemical reduction method was used for preparation of reduced graphene oxide/hydroxyapatite (rGO/HAp) nanocomposites. •The rGO/HAp nanocomposites exhibited good biocompatibility with hMSCs. •Selective chemical sensor based on rGO/HAp nanocomposites was developed for detection of Bis-phenol A. •The fabricated rGO/HAp/Nafion/GCE sensor exhibited good detection limit of 60 pmol L −1 . -- Abstract: A facile and cost effective chemical reduction method is employed for the preparation of reduced graphene oxide/hydroxyapatite (rGO/HAp) nanocomposites. The transmission electron microscopy images revealed that the HAp flakes are well decorated on the surface of rGO. The morphological structure of the as-synthesized rGO/HAp nanocomposites was confirmed through X-ray diffraction, Fourier transform infrared spectroscopy and Raman spectroscopy, while the composition and thermal stability were analyzed by energy dispersive spectra and thermogravimetric analysis, respectively. Furthermore, the effect of rGO/HAp nanocomposites for the proliferation of Human Mesenchymal Stem Cell (hMSC) was performed to confirm the biocompatibility. A selective chemical sensor based on rGO/HAp modified glassy carbon electrode (GCE) for sensitive detection of Bis-phenol A (BPA) has been developed. Several important parameters controlling the performance of the BPA chemi-sensor were investigated and optimized at room conditions. The rGO/HAp/Nafion/GCE sensor offers a fast response and highly sensitive BPA detection. Under the optimal conditions, a linear range from 0.2 nmol L −1 to 2.0 mmol L −1 for the detection of BPA was observed with the detection limit of 60.0 pmol L −1 (signal-to-noise ratio, at an SNR of 3) and sensitivity of 18.98 × 10 4 μA.L/μmol.m 2 . Meanwhile, the fabricated chemi-sensor showed an excellent, specific and selective recognition to target BPA molecules among coexistence of other analytes in the buffer system. This novel effort initiated

  4. Development of highly porous scaffolds based on bioactive silicates for dental tissue engineering

    International Nuclear Information System (INIS)

    Goudouri, O.M.; Theodosoglou, E.; Kontonasaki, E.; Will, J.; Chrissafis, K.; Koidis, P.; Paraskevopoulos, K.M.; Boccaccini, A.R.

    2014-01-01

    Graphical abstract: - Highlights: • Synthesis of an Mg-based glass-ceramic via the sol–gel technique. • The heat treatment of the glass-ceramic promoted the crystallization of akermanite. • Akermanite scaffolds coated with gelatin were successfully fabricated. • An HCAp layer was developed on the surface of all scaffolds after 9 days in SBF. - Abstract: Various scaffolding materials, ceramics and especially Mg-based ceramic materials, including akermanite (Ca 2 MgSi 2 O 7 ) and diopside (CaMgSi 2 O 6 ), have attracted interest for dental tissue regeneration because of their improved mechanical properties and controllable biodegradation. The aim of the present work was the synthesis of an Mg-based glass-ceramic, which would be used for the construction of workable akermanite scaffolds. The characterization of the synthesized material was performed by Fourier Transform Infrared Spectroscopy (FTIR) X-Ray Diffractometry (XRD) and Scanning Electron Microscopy (SEM). Finally, the apatite forming ability of the scaffolds was assessed by immersion in simulated body fluid. The scaffolds were fabricated by the foam replica technique and were subsequently coated with gelatin to provide a functional surface for increased cell attachment. Finally, SEM microphotographs and FTIR spectra of the scaffolds after immersion in SBF solution indicated the inorganic bioactive character of the scaffolds suitable for the intended applications in dental tissue engineering

  5. Development of highly porous scaffolds based on bioactive silicates for dental tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Goudouri, O.M., E-mail: menti.goudouri@ww.uni-erlangen.de [Institute for Biomaterials, University of Erlangen-Nuremberg, 91058 Erlangen (Germany); Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Theodosoglou, E. [School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kontonasaki, E. [Department of Fixed Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Will, J. [Institute for Biomaterials, University of Erlangen-Nuremberg, 91058 Erlangen (Germany); Chrissafis, K. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Koidis, P. [Department of Fixed Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Paraskevopoulos, K.M. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Boccaccini, A.R. [Institute for Biomaterials, University of Erlangen-Nuremberg, 91058 Erlangen (Germany)

    2014-01-01

    Graphical abstract: - Highlights: • Synthesis of an Mg-based glass-ceramic via the sol–gel technique. • The heat treatment of the glass-ceramic promoted the crystallization of akermanite. • Akermanite scaffolds coated with gelatin were successfully fabricated. • An HCAp layer was developed on the surface of all scaffolds after 9 days in SBF. - Abstract: Various scaffolding materials, ceramics and especially Mg-based ceramic materials, including akermanite (Ca{sub 2}MgSi{sub 2}O{sub 7}) and diopside (CaMgSi{sub 2}O{sub 6}), have attracted interest for dental tissue regeneration because of their improved mechanical properties and controllable biodegradation. The aim of the present work was the synthesis of an Mg-based glass-ceramic, which would be used for the construction of workable akermanite scaffolds. The characterization of the synthesized material was performed by Fourier Transform Infrared Spectroscopy (FTIR) X-Ray Diffractometry (XRD) and Scanning Electron Microscopy (SEM). Finally, the apatite forming ability of the scaffolds was assessed by immersion in simulated body fluid. The scaffolds were fabricated by the foam replica technique and were subsequently coated with gelatin to provide a functional surface for increased cell attachment. Finally, SEM microphotographs and FTIR spectra of the scaffolds after immersion in SBF solution indicated the inorganic bioactive character of the scaffolds suitable for the intended applications in dental tissue engineering.

  6. Preparation, characterization and biological test of 3D-scaffolds based on chitosan, fibroin and hydroxyapatite for bone tissue engineering.

    Science.gov (United States)

    Lima, Paulo Autran Leite; Resende, Cristiane Xavier; Soares, Glória Dulce de Almeida; Anselme, Karine; Almeida, Luís Eduardo

    2013-08-01

    This work describes the preparation and characterization of porous 3D-scaffolds based on chitosan (CHI), chitosan/silk fibroin (CHI/SF) and chitosan/silk fibroin/hydroxyapatite (CHI/SF/HA) by freeze drying. The biomaterials were characterized by X-ray diffraction, attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy and energy dispersive spectroscopy. In addition, studies of porosity, pore size, contact angle and biological response of SaOs-2osteoblastic cells were performed. The CHI scaffolds have a porosity of 94.2±0.9%, which is statistically higher than the one presented by CHI/SF/HA scaffolds, 89.7±2.6%. Although all scaffolds were able to promote adhesion, growth and maintenance of osteogenic differentiation of SaOs-2 cells, the new 3D-scaffold based on CHI/SF/HA showed a significantly higher cell growth at 7 days and 21 days and the level of alkaline phosphatase at 14 and 21 days was statistically superior compared to other tested materials. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Ceria-containing uncoated and coated hydroxyapatite-based galantamine nanocomposites for formidable treatment of Alzheimer's disease in ovariectomized albino-rat model

    Energy Technology Data Exchange (ETDEWEB)

    Wahba, Sanaa M.R. [Zoology Department, Women College, Ain Shams University, 11566 Cairo (Egypt); Darwish, Atef S., E-mail: atef_mouharam@sci.asu.edu.eg [Chemistry Department, Faculty of Science, Ain Shams University, Cairo (Egypt); Kamal, Sara M. [Zoology Department, Women College, Ain Shams University, 11566 Cairo (Egypt)

    2016-08-01

    This paper upraises delivery and therapeutic actions of galantamine drug (GAL) against Alzheimer's disease (AD) in rat brain through attaching GAL to ceria-containing hydroxyapatite (GAL@Ce-HAp) as well ceria-containing carboxymethyl chitosan-coated hydroxyapatite (GAL@Ce-HAp/CMC) nanocomposites. Physicochemical features of such nanocomposites were analyzed by XRD, FT-IR, Raman spectroscopy, UV–vis spectrophotometer, N{sub 2}-BET, DLS, zeta-potential measurements, SEM, and HR-TEM. Limited interactions were observed in GAL@Ce-HAp with prevailed existence of dispersed negatively charged rod-like particles conjugated with ceria nanodots. On contrary, GAL@Ce-HAp/CMC was well-structured developing aggregates of uncharged tetragonal-shaped particles laden with accession of ceria quantum dots. Such nanocomposites were i.p. injected into ovariectomized AD albino-rats at galantamine dose of 2.5 mg/kg/day for one month, then brain tissues were collected for biochemical and histological tests. GAL@Ce-HAp adopted as a promising candidate for AD curativeness, whereas oxidative stress markers were successfully upregulated, degenerated neurons in hippocampal and cerebral tissues were wholly recovered and Aβ-plaques were vanished. Also, optimizable in-vitro release for GAL and nanoceria were displayed from GAL@Ce-HAp, while delayed in-vitro release for those species were developed from GAL@Ce-HAp/CMC. This proof of concept work allow futuristic omnipotency of rod-like hydroxyapatite particles for selective delivery of GAL and nanoceria to AD affected brain areas. - Highlights: • Ceria affords existence of negatively charged rod-like architecture hydroxyapatite. • Carboxymethyl chitosan-coated apatite adopts neutral tetragonal-shaped species. • Ceria-containing apatite-based galantamine composite is potent anti-Alzheimer drug. • Typical neurons act via Alzheimer curing by ceria-loading apatite-based galantamine.

  8. Ceria-containing uncoated and coated hydroxyapatite-based galantamine nanocomposites for formidable treatment of Alzheimer's disease in ovariectomized albino-rat model

    International Nuclear Information System (INIS)

    Wahba, Sanaa M.R.; Darwish, Atef S.; Kamal, Sara M.

    2016-01-01

    This paper upraises delivery and therapeutic actions of galantamine drug (GAL) against Alzheimer's disease (AD) in rat brain through attaching GAL to ceria-containing hydroxyapatite (GAL@Ce-HAp) as well ceria-containing carboxymethyl chitosan-coated hydroxyapatite (GAL@Ce-HAp/CMC) nanocomposites. Physicochemical features of such nanocomposites were analyzed by XRD, FT-IR, Raman spectroscopy, UV–vis spectrophotometer, N_2-BET, DLS, zeta-potential measurements, SEM, and HR-TEM. Limited interactions were observed in GAL@Ce-HAp with prevailed existence of dispersed negatively charged rod-like particles conjugated with ceria nanodots. On contrary, GAL@Ce-HAp/CMC was well-structured developing aggregates of uncharged tetragonal-shaped particles laden with accession of ceria quantum dots. Such nanocomposites were i.p. injected into ovariectomized AD albino-rats at galantamine dose of 2.5 mg/kg/day for one month, then brain tissues were collected for biochemical and histological tests. GAL@Ce-HAp adopted as a promising candidate for AD curativeness, whereas oxidative stress markers were successfully upregulated, degenerated neurons in hippocampal and cerebral tissues were wholly recovered and Aβ-plaques were vanished. Also, optimizable in-vitro release for GAL and nanoceria were displayed from GAL@Ce-HAp, while delayed in-vitro release for those species were developed from GAL@Ce-HAp/CMC. This proof of concept work allow futuristic omnipotency of rod-like hydroxyapatite particles for selective delivery of GAL and nanoceria to AD affected brain areas. - Highlights: • Ceria affords existence of negatively charged rod-like architecture hydroxyapatite. • Carboxymethyl chitosan-coated apatite adopts neutral tetragonal-shaped species. • Ceria-containing apatite-based galantamine composite is potent anti-Alzheimer drug. • Typical neurons act via Alzheimer curing by ceria-loading apatite-based galantamine.

  9. TSDC and impedance spectroscopy measurements on hydroxyapatite, β-tricalcium phosphate and hydroxyapatite/β-tricalcium phosphate biphasic bioceramics

    Science.gov (United States)

    Prezas, P. R.; Melo, B. M. G.; Costa, L. C.; Valente, M. A.; Lança, M. C.; Ventura, J. M. G.; Pinto, L. F. V.; Graça, M. P. F.

    2017-12-01

    Bone grafting and surgical interventions related with orthopaedic disorders consist in a big business, generating large revenues worldwide every year. There is a need to replace the biomaterials that currently still dominate this market, i.e., autografts and allografts, due to their disadvantages, such as limited availability, need for additional surgeries and diseases transmission possibilities. The most promising replacement materials are biomaterials with bioactive properties, such as the calcium phosphate-based bioceramics group. The bioactivity of these materials, i.e., the rate at which they promote the growth and directly bond with the new host biological bone, can be enhanced through their electrical polarization. In the present work, the electrical polarization features of pure hydroxyapatite (Hap), pure β-tricalcium phosphate (β-TCP) and biphasic hydroxyapatite/β-tricalcium phosphate composites (HTCP) were analyzed by measuring thermally stimulated depolarization currents (TSDC). The samples were thermoelectrically polarized at 500 °C under a DC electric field with a magnitude of 5 kV/cm. The biphasic samples were also polarized under electric fields with different magnitudes: 2, 3, 4 and 5 kV/cm. Additionally, the depolarization processes detected in the TSDC measurements were correlated with dielectric relaxation processes observed in impedance spectroscopy (IS) measurements. The results indicate that the β-TCP crystalline phase has a considerable higher ability to store electrical charge compared with the Hap phase. This indicates that it has a suitable composition and structure for ionic conduction and establishment of a large electric charge density, providing great potential for orthopaedic applications.

  10. Degradation of milk-based bioactive peptides by yogurt fermentation bacteria.

    Science.gov (United States)

    Paul, M; Somkuti, G A

    2009-09-01

    To analyse the effect of cell-associated peptidases in yogurt starter culture strains Lactobacillus delbrueckii ssp. bulgaricus (LB) and Streptococcus thermophilus (ST) on milk-protein-based antimicrobial and hypotensive peptides in order to determine their survival in yogurt-type dairy foods. The 11mer antimicrobial and 12mer hypotensive milk-protein-derived peptides were incubated with mid-log cells of LB and ST, which are required for yogurt production. Incubations were performed at pH 4.5 and 7.0, and samples removed at various time points were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC). The peptides remained mostly intact at pH 4.5 in the presence of ST strains and moderately digested by exposure to LB cells. Peptide loss occurred more rapidly and was more extensive after incubation at pH 7.0. The 11mer and 12mer bioactive peptides may be added at the end of the yogurt-making process when the pH level has dropped to 4.5, limiting the overall extent of proteolysis. The results show the feasibility of using milk-protein-based antimicrobial and hypotensive peptides as food supplements to improve the health-promoting qualities of liquid and semi-solid dairy foods prepared by the yogurt fermentation process.

  11. Improvement of Bioactive Compound Classification through Integration of Orthogonal Cell-Based Biosensing Methods

    Directory of Open Access Journals (Sweden)

    Goran N. Jovanovic

    2007-01-01

    Full Text Available Lack of specificity for different classes of chemical and biological agents, and false positives and negatives, can limit the range of applications for cell-based biosensors. This study suggests that the integration of results from algal cells (Mesotaenium caldariorum and fish chromatophores (Betta splendens improves classification efficiency and detection reliability. Cells were challenged with paraquat, mercuric chloride, sodium arsenite and clonidine. The two detection systems were independently investigated for classification of the toxin set by performing discriminant analysis. The algal system correctly classified 72% of the bioactive compounds, whereas the fish chromatophore system correctly classified 68%. The combined classification efficiency was 95%. The algal sensor readout is based on fluorescence measurements of changes in the energy producing pathways of photosynthetic cells, whereas the response from fish chromatophores was quantified using optical density. Change in optical density reflects interference with the functioning of cellular signal transduction networks. Thus, algal cells and fish chromatophores respond to the challenge agents through sufficiently different mechanisms of action to be considered orthogonal.

  12. Investigating an organ-targeting platform based on hydroxyapatite nanoparticles using a novel in situ method of radioactive {sup 125}Iodine labeling

    Energy Technology Data Exchange (ETDEWEB)

    Ignjatović, Nenad [Centre for Fine Particles Processing and Nanotechnologies, Institute of Technical Sciences of the Serbian Academy of Science and Arts, Knez Mihailova 35/4, 11000 Belgrade (Serbia); Vranješ Djurić, Sanja [Laboratory for Radioisotopes, Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001 Belgrade (Serbia); Mitić, Žarko [Faculty of Medicine, Department of Pharmacy, University of Niš, Bulevar dr Zorana Đinđića 81, 18000 Niš (Serbia); Janković, Drina [Laboratory for Radioisotopes, Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001 Belgrade (Serbia); Uskoković, Dragan, E-mail: dragan.uskokovic@itn.sanu.ac.rs [Centre for Fine Particles Processing and Nanotechnologies, Institute of Technical Sciences of the Serbian Academy of Science and Arts, Knez Mihailova 35/4, 11000 Belgrade (Serbia)

    2014-10-01

    In this study, we have investigated the synthesis of nanoparticles of hydroxyapatite (HAp) and hydroxyapatite coated with chitosan (HAp/Ch) and the chitosan-poly-D,L-lactide-co-glycolide polymer blend (HAp/Ch-PLGA) as an organ-targeting system. We have examined and defined the final destination, as well as the dynamics and the pathways of the synthesized particles following intravenous administration in vivo. The XRD, ZP, FT-IR and SEM analyses have confirmed that the hydroxyapatite nanoparticles with d{sub 50} = 72 nm are coated with polymers. Radioactive 125-Iodine ({sup 125}I), a low energy gamma emitter, was used to develop a novel in situ method for the radiolabeling of particles and investigation of their biodistribution. {sup 125}I-labeled particles exhibited high stability in saline and serum over the second day, which justified their use in the following in vivo studies. The biodistribution of {sup 125}I-labeled particles after intravenous injection in rats differed significantly: HAp particles mostly targeted the liver, HAp/Ch the spleen and the liver, while HAp/Ch-PLGA targeted the lungs. Twenty-four hours post injection, HAp particles were excreted completely, while both {sup 125}I-HAp/Ch and {sup 125}I-HAp/Ch-PLGA were retained in the body for a prolonged period of time with more than 20% of radioactivity still found in different organs. - Highlights: • An organ-targeting carrier based on nano-hydroxyapatite • In situ labeling • Biodistribution of {sup 125}I-labeled HAp particles.

  13. Hydroxyapatite-based sorbents: elaboration, characterization and application for the removal of catechol from the aqueous phase.

    Science.gov (United States)

    Sebei, Haroun; Pham Minh, Doan; Lyczko, Nathalie; Sharrock, Patrick; Nzihou, Ange

    2017-10-01

    Hydroxyapatite (HAP) is highly considered as good sorbent for the removal of metals from the aqueous phase. However, soluble metals co-exist with organic pollutants in wastewaters. But little work has been devoted to investigate the reactivity of HAP for the removal of organic compounds. The main objective of this work is to study the reactivity of HAP-based sorbents for the removal of catechol as a model organic pollutant from an aqueous solution. Thus, HAP sorbents were firstly synthesized using calcium carbonate and potassium dihydrogen phosphate under moderate conditions (25-80°C, atmospheric pressure). A zinc-doped HAP was also used as sorbent, which was obtained from the contact of HAP with an aqueous solution of zinc nitrate. All the sorbents were characterized by different standard physico-chemical techniques. The sorption of catechol was carried out in a batch reactor under stirring at room temperature and pressure. Zinc-doped HAP sorbent was found to be more reactive than non-doped HAP sorbents for the fixation of catechol. The highest sorption capacity was of 15 mg of C per gram of zinc-doped HAP sorbent. The results obtained suggest the reaction scheme of HAP sorbents with metals and organic pollutants when HAP sorbents were used for the treatment of complex wastewaters.

  14. New nanostructural biomaterials based on active silicate systems and hydroxyapatite: characterization and genotoxicity in human peripheral blood lymphocytes.

    Science.gov (United States)

    Opačić-Galić, V; Petrović, V; Zivković, S; Jokanović, V; Nikolić, B; Knežević-Vukčević, J; Mitić-Ćulafić, D

    2013-06-01

    To characterize and investigate the genotoxic effect of a new endodontic cement based on dicalcium- and tricalcium-silicate (CS) with hydroxyapatite (HA) on human lymphocytes. Hydrothermal treatment was applied for synthesis of CS and HA. The final mixture HA-CS, with potential to be used in endodontic practice, is composed of CS (34%) and HA (66%). Human lymphocytes were incubated with HA, HA-CS and CS for 1 h, at 37 °C and 5% CO2. Cell viability was determined using the trypan blue exclusion assay. To evaluate the level of DNA damage comet assay (single cell gel electrophoresis) was performed. For the statistical analysis anova and Duncan's Post Hoc Test were used. The SEM analysis indicated that CS consisted mostly of agglomerates of several micrometers in size, built up from smaller particles, with dimensions between 117 and 477 nm. This is promising because dimensions of agglomerates are not comparable with channels inside the cell membranes, whereas their nano-elements provide evident activity, important for faster setting of these mixtures compared to MTA. Values of DNA damage obtained in the comet assay indicated low genotoxic risk of the new endodontic materials. The significantly improved setting characteristics and low genotoxic risk of the new material support further research. © 2012 International Endodontic Journal.

  15. Bio-based polyurethane for tissue engineering applications: How hydroxyapatite nanoparticles influence the structure, thermal and biological behavior of polyurethane composites.

    Science.gov (United States)

    Gabriel, Laís P; Santos, Maria Elizabeth M Dos; Jardini, André L; Bastos, Gilmara N T; Dias, Carmen G B T; Webster, Thomas J; Maciel Filho, Rubens

    2017-01-01

    In this work, thermoset polyurethane composites were prepared by the addition of hydroxyapatite nanoparticles using the reactants polyol polyether and an aliphatic diisocyanate. The polyol employed in this study was extracted from the Euterpe oleracea Mart. seeds from the Amazon Region of Brazil. The influence of hydroxyapatite nanoparticles on the structure and morphology of the composites was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), the structure was evaluated by Fourier transform infrared spectroscopy (FT-IR), thermal properties were analyzed by thermogravimetry analysis (TGA), and biological properties were studied by in vitro and in vivo studies. It was found that the addition of HA nanoparticles promoted fibroblast adhesion while in vivo investigations with histology confirmed that the composites promoted connective tissue adherence and did not induce inflammation. In this manner, this study supports the further investigation of bio-based, polyurethane/hydroxyapatite composites as biocompatible scaffolds for numerous tissue engineering applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Bactericidal strontium-releasing injectable bone cements based on bioactive glasses.

    Science.gov (United States)

    Brauer, Delia S; Karpukhina, Natalia; Kedia, Gopal; Bhat, Aditya; Law, Robert V; Radecka, Izabela; Hill, Robert G

    2013-01-06

    Strontium-releasing injectable bone cements may have the potential to prevent implant-related infections through the bactericidal action of strontium, while enhancing bone formation in patients suffering from osteoporosis. A melt-derived bioactive glass (BG) series (SiO2–CaO–CaF2–MgO) with 0–50% of calcium substituted with strontium on a molar base were produced. By mixing glass powder, poly(acrylic acid) and water, cements were obtained which can be delivered by injection and set in situ, giving compressive strength of up to 35 MPa. Strontium release was dependent on BG composition with increasing strontium substitution resulting in higher concentrations in the medium. Bactericidal effects were tested on Staphylococcus aureus and Streptococcus faecalis; cell counts were reduced by up to three orders of magnitude over 6 days. Results show that bactericidal action can be increased through BG strontium substitution, allowing for the design of novel antimicrobial and bone enhancing cements for use in vertebroplasty or kyphoplasty for treating osteoporosis-related vertebral compression fractures.

  17. Electric-field triggered controlled release of bioactive volatiles from imine-based liquid crystalline phases.

    Science.gov (United States)

    Herrmann, Andreas; Giuseppone, Nicolas; Lehn, Jean-Marie

    2009-01-01

    Application of an electric field to liquid crystalline film forming imines with negative dielectric anisotropy, such as N-(4-methoxybenzylidene)-4-butylaniline (MBBA, 1), results in the expulsion of compounds that do not participate in the formation of the liquid crystalline phase. Furthermore, amines and aromatic aldehydes undergo component exchange with the imine by generating constitutional dynamic libraries. The strength of the electric field and the duration of its application to the liquid crystalline film influence the release rate of the expelled compounds and, at the same time, modulate the equilibration of the dynamic libraries. The controlled release of volatile organic molecules with different chemical functionalities from the film was quantified by dynamic headspace analysis. In all cases, higher headspace concentrations were detected in the presence of an electric field. These results point to the possibility of using imine-based liquid crystalline films to build devices for the controlled release of a broad variety of bioactive volatiles as a direct response to an external electric signal.

  18. Hydroxyapatite Fibers: A Review of Synthesis Methods

    Science.gov (United States)

    Qi, Mei-Li; He, Kun; Huang, Zhen-Nan; Shahbazian-Yassar, Reza; Xiao, Gui-Yong; Lu, Yu-Peng; Shokuhfar, Tolou

    2017-08-01

    Hydroxyapatite (HA) exhibits excellent biocompatibility, bioactivity, osteoconductivity, non-toxicity and so on, making it a perfect candidate for biomedical applications. However, HA is not qualified to be used in load-bearing sites due to its poor flexural strength and fracture toughness. Design, synthesis and application of fibrous HA is a promising strategy to overcome the inherent brittleness. This review provides a brief description of HA and hydroxyapatite fiber (HAF), then introduces different synthesis methods of HAF and highlights the inherent merits and drawbacks involved in each method. Finally, the future perspectives in this active research area are given. The purpose of this review is to acquaint the reader with this promising new field of biomaterials research and with emphasis on recent techniques to obtain continuous, uniform and long HAF.

  19. Biocomposite scaffolds based on electrospun poly(3-hydroxybutyrate) nanofibers and electrosprayed hydroxyapatite nanoparticles for bone tissue engineering applications

    International Nuclear Information System (INIS)

    Ramier, Julien; Bouderlique, Thibault; Stoilova, Olya; Manolova, Nevena; Rashkov, Iliya; Langlois, Valérie; Renard, Estelle; Albanese, Patricia; Grande, Daniel

    2014-01-01

    The electrospinning technique combined with the electrospraying process provides a straightforward and versatile approach for the fabrication of novel nanofibrous biocomposite scaffolds with structural, mechanical, and biological properties potentially suitable for bone tissue regeneration. In this comparative investigation, three types of poly(3-hydroxybutyrate) (PHB)-based scaffolds were engineered: (i) PHB mats by electrospinning of a PHB solution, (ii) mats of PHB/hydroxyapatite nanoparticle (nHA) blends by electrospinning of a mixed solution containing PHB and nHAs, and (iii) mats constituted of PHB nanofibers and nHAs by simultaneous electrospinning of a PHB solution and electrospraying of a nHA dispersion. Scaffolds based on PHB/nHA blends displayed improved mechanical properties compared to those of neat PHB mats, due to the incorporation of nHAs within the fibers. The electrospinning/electrospraying approach afforded biocomposite scaffolds with lower mechanical properties, due to their higher porosity, but they displayed slightly better biological properties. In the latter case, the bioceramic, i.e. nHAs, largely covered the fiber surface, thus allowing for a direct exposure to cells. The 21 day-monitoring through the use of MTS assays and SEM analyses demonstrated that human mesenchymal stromal cells (hMSCs) remained viable on PHB/nHA biocomposite scaffolds and proliferated continuously until reaching confluence. - Highlights: • Three different types of PHB-based scaffolds are engineered and thoroughly investigated. • The combination of electrospinning and electrospraying affords original nanofibrous biocomposite scaffolds. • PHB-based scaffolds show a strong capability of supporting viable cell development for 21 days

  20. Biocomposite scaffolds based on electrospun poly(3-hydroxybutyrate) nanofibers and electrosprayed hydroxyapatite nanoparticles for bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Ramier, Julien [Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS, Université Paris-Est Créteil, 2, rue Henri Dunant, 94320 Thiais (France); Bouderlique, Thibault [Laboratoire “Croissance, Réparation et Régénération Tissulaires”, EAC 7149 CNRS, Université Paris-Est Créteil, 61, avenue du Général de Gaulle, 94010 Créteil (France); Stoilova, Olya; Manolova, Nevena; Rashkov, Iliya [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St., bl. 103A, BG-1113 Sofia (Bulgaria); Langlois, Valérie; Renard, Estelle [Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS, Université Paris-Est Créteil, 2, rue Henri Dunant, 94320 Thiais (France); Albanese, Patricia [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St., bl. 103A, BG-1113 Sofia (Bulgaria); Grande, Daniel, E-mail: grande@icmpe.cnrs.fr [Institut de Chimie et des Matériaux Paris-Est, UMR 7182 CNRS, Université Paris-Est Créteil, 2, rue Henri Dunant, 94320 Thiais (France)

    2014-05-01

    The electrospinning technique combined with the electrospraying process provides a straightforward and versatile approach for the fabrication of novel nanofibrous biocomposite scaffolds with structural, mechanical, and biological properties potentially suitable for bone tissue regeneration. In this comparative investigation, three types of poly(3-hydroxybutyrate) (PHB)-based scaffolds were engineered: (i) PHB mats by electrospinning of a PHB solution, (ii) mats of PHB/hydroxyapatite nanoparticle (nHA) blends by electrospinning of a mixed solution containing PHB and nHAs, and (iii) mats constituted of PHB nanofibers and nHAs by simultaneous electrospinning of a PHB solution and electrospraying of a nHA dispersion. Scaffolds based on PHB/nHA blends displayed improved mechanical properties compared to those of neat PHB mats, due to the incorporation of nHAs within the fibers. The electrospinning/electrospraying approach afforded biocomposite scaffolds with lower mechanical properties, due to their higher porosity, but they displayed slightly better biological properties. In the latter case, the bioceramic, i.e. nHAs, largely covered the fiber surface, thus allowing for a direct exposure to cells. The 21 day-monitoring through the use of MTS assays and SEM analyses demonstrated that human mesenchymal stromal cells (hMSCs) remained viable on PHB/nHA biocomposite scaffolds and proliferated continuously until reaching confluence. - Highlights: • Three different types of PHB-based scaffolds are engineered and thoroughly investigated. • The combination of electrospinning and electrospraying affords original nanofibrous biocomposite scaffolds. • PHB-based scaffolds show a strong capability of supporting viable cell development for 21 days.

  1. Enhancement of cell-based therapeutic angiogenesis using a novel type of injectable scaffolds of hydroxyapatite-polymer nanocomposite microspheres.

    Directory of Open Access Journals (Sweden)

    Yohei Mima

    Full Text Available BACKGROUND: Clinical trials demonstrate the effectiveness of cell-based therapeutic angiogenesis in patients with severe ischemic diseases; however, their success remains limited. Maintaining transplanted cells in place are expected to augment the cell-based therapeutic angiogenesis. We have reported that nano-hydroxyapatite (HAp coating on medical devices shows marked cell adhesiveness. Using this nanotechnology, HAp-coated poly(l-lactic acid (PLLA microspheres, named nano-scaffold (NS, were generated as a non-biological, biodegradable and injectable cell scaffold. We investigate the effectiveness of NS on cell-based therapeutic angiogenesis. METHODS AND RESULTS: Bone marrow mononuclear cells (BMNC and NS or control PLLA microspheres (LA were intramuscularly co-implanted into mice ischemic hindlimbs. When BMNC derived from enhanced green fluorescent protein (EGFP-transgenic mice were injected into ischemic muscle, the muscle GFP level in NS+BMNC group was approximate fivefold higher than that in BMNC or LA+BMNC groups seven days after operation. Kaplan-Meier analysis demonstrated that NS+BMNC markedly prevented hindlimb necrosis (P<0.05 vs. BMNC or LA+BMNC. NS+BMNC revealed much higher induction of angiogenesis in ischemic tissues and collateral blood flow confirmed by three-dimensional computed tomography angiography than those of BMNC or LA+BMNC groups. NS-enhanced therapeutic angiogenesis and arteriogenesis showed good correlations with increased intramuscular levels of vascular endothelial growth factor and fibroblast growth factor-2. NS co-implantation also prevented apoptotic cell death of transplanted cells, resulting in prolonged cell retention. CONCLUSION: A novel and feasible injectable cell scaffold potentiates cell-based therapeutic angiogenesis, which could be extremely useful for the treatment of severe ischemic disorders.

  2. Impact of high-intensity pulsed electric fields on bioactive compounds in Mediterranean plant-based foods.

    Science.gov (United States)

    Elez-Martínez, Pedro; Soliva-Fortuny, Robert; Martín-Belloso, Olga

    2009-05-01

    Novel non-thermal processing technologies such as high-intensity pulsed electric field (HIPEF) treatments may be applied to pasteurize plant-based liquid foods as an alternative to conventional heat treatments. In recent years, there has been an increasing interest in HIPEF as a way of preserving and extending the shelf-life of liquid products without the quality damage caused by heat treatments. However, less attention has been paid to the effects of HIPEF on minor constituents of these products, namely bioactive compounds. This review is a state-of-the-art update on the effects of HIPEF treatments on health-related compounds in plants of the Mediterranean diet such as fruit juices, and Spanish gazpacho. The relevance of HIPEF-processing parameters on retaining plant-based bioactive compounds will be discussed.

  3. Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

    Science.gov (United States)

    Shrivastava, Pragya; Dalai, Sridhar; Sudera, Prerna; Sivam, Santosh Param; Vijayalakshmi, S.; Sharma, Pratibha

    2013-02-01

    With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO2 70 mol%, CaO 26 mol % and P2O5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

  4. Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

    International Nuclear Information System (INIS)

    Shrivastava, Pragya; Dalai, Sridhar; Vijayalakshmi, S.; Sudera, Prerna; Sivam, Santosh Param; Sharma, Pratibha

    2013-01-01

    With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO 2 70 mol%, CaO 26 mol % and P 2 O 5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

  5. Fabrication and mechanical evaluation of hydroxyapatite/oxide nano-composite materials.

    Science.gov (United States)

    Mohamed, Khaled R; Beherei, Hanan H; El Bassyouni, Gehan T; El Mahallawy, Nahed

    2013-10-01

    In the current study, the semiconducting metal oxides such as nano-ZnO and SiO2 powders were prepared via sol-gel technique and conducted on nano-hydroxyapatite (nHA) which was synthesized by chemical precipitation. The properties of fabricated nano-structured composites containing different ratios of HA, ZnO and SiO2 were examined using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The effect of the variation of ratios between the three components on mechanical, microstructure and in-vitro properties was assessed to explore the possibility of enhancing these properties. The results proved that the mechanical properties exhibited an increment with increasing the ZnO content at the extent of HA. In-vitro study proved the formation and nucleation of apatite onto the surface of the fabricated composites after one week of immersion. It is concluded that HA composites containing SiO2 or SiO2/ZnO content had a suitable mechanical properties and ability to form apatite particles onto the composite surface. Based on bioactivity behavior, Si-HA is more bioactive than pure hydroxyapatite and nano-arrangements will provide an interface for better bone formation. Therefore, these nano-composites will be promising as bone substitutes especially in load bearing sites. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Selection of rhizosphere local microbial as bioactive inoculant based on irradiated compost

    International Nuclear Information System (INIS)

    Dadang Sudrajat; Nana Mulyana; Arief Adhari

    2014-01-01

    One of the main components of carrier based on irradiation compost for bio organic fertilizer is a potential microbial isolates role in nutrient supply and growth hormone. This research was conducted to obtain microbial isolates from plant root zone (rhizosphere), further isolation and selection in order to obtain potential isolates capable of nitrogen fixation (N 2 ), resulting in growth hormone (Indole Acetic Acid), and phosphate solubilizing. Selected potential isolates used as bioactive microbial inoculants formulation in irradiation compost based. Forty eight (48) rhizosphere samples were collected from different areas of West and Central Java. One hundred sixteen (116) isolates have been characterized for their morphological, cultural, staining and biochemical characteristics. Isolates have been selected for further screening of PGPR traits. Parameters assessed were Indole Acetic Acid (IAA) content analysis with colorimetric methods, dinitrogen fixation using gas chromatography, phosphate solubility test qualitatively (in the media pikovskaya) and quantitative assay of dissolved phosphate (spectrophotometry). Evaluation of the ability of selected isolates on the growth of corn plants were done in pots. The isolates will be used as inoculant consortium base on compost irradiation. The selection obtained eight (8) bacterial isolates identified as Bacillus circulans (3 isolates), Bacillus stearothermophilus (1 isolate), Azotobacter sp (3 isolates), Pseudomonas diminuta (1 isolate). The highest phosphate released (91,21 mg/l) was by BD2 isolate (Bacillus circulan) with a holo zone size (1.32 cm) on Pikovskaya agar medium. Isolate of Pseudomonas diminuta (KACI) was capable to produce the highest IAA hormone (74.34 μg/ml). The highest nitrogen (N 2 ) fixation activity was shown by Azotobacter sp isolates (KDB2) at a rate of 235.05 nmol/hour. The viability test showed that all selected isolates in compost irradiation carrier slightly decreased after 3 months of

  7. Spectral analysis of allogeneic hydroxyapatite powders

    Science.gov (United States)

    Timchenko, P. E.; Timchenko, E. V.; Pisareva, E. V.; Vlasov, M. Yu; Red'kin, N. A.; Frolov, O. O.

    2017-01-01

    In this paper we discuss the application of Raman spectroscopy to the in vitro analysis of the hydroxyapatite powder samples produced from different types of animal bone tissue during demineralization process at various acid concentrations and exposure durations. The derivation of the Raman spectrum of hydroxyapatite is attempted by the analysis of the pure powders of its known constituents. Were experimentally found spectral features of hydroxyapatite, based on analysis of the line amplitude at wave numbers 950-965 cm-1 ((PO4)3- (ν1) vibration) and 1065-1075 cm-1 ((CO3)2-(ν1) B-type replacement). Control of physicochemical properties of hydroxyapatite was carried out by Raman spectroscopy. Research results are compared with an infrared Fourier spectroscopy.

  8. Spectral analysis of allogeneic hydroxyapatite powders

    International Nuclear Information System (INIS)

    Timchenko, P E; Timchenko, E V; Pisareva, E V; Vlasov, M Yu; Red’kin, N A; Frolov, O O

    2017-01-01

    In this paper we discuss the application of Raman spectroscopy to the in vitro analysis of the hydroxyapatite powder samples produced from different types of animal bone tissue during demineralization process at various acid concentrations and exposure durations. The derivation of the Raman spectrum of hydroxyapatite is attempted by the analysis of the pure powders of its known constituents. Were experimentally found spectral features of hydroxyapatite, based on analysis of the line amplitude at wave numbers 950-965 cm -1 ((PO 4 ) 3- (ν 1 ) vibration) and 1065-1075 cm -1 ((CO 3 ) 2- (ν 1 ) B-type replacement). Control of physicochemical properties of hydroxyapatite was carried out by Raman spectroscopy. Research results are compared with an infrared Fourier spectroscopy. (paper)

  9. The possibilities of atmospheric plasma-spraying application to obtain hydroxyapatite coatings on the stainless steel samples

    Directory of Open Access Journals (Sweden)

    Mihailović Marija D.

    2013-01-01

    Full Text Available For decades, the standard metallic materials for hip implants, besides the 316LVM stainless steel, were titanium- and cobalt/chromium-based alloys. Although bioinert, due to their corrosion resistance, they are not biocompatible. Contemporary surgical implants are not made just of bioinert metal anymore, but with deposited bioactive hydroxyapatite (HAp coating. Hydroxyapatite is chemically identical with the mineral constituent of bones and teeth, what besides its biocompatibility provides bioactivity as well. The HAp limitations are, however, weak tensile strength and low fatigue resistance for long term loadings, if used alone. This is the reason for HAp to be deposited onto the surgical implant, and to enable its bioactivity, what means intergrowth with bones, and therefore the long-lasting and mechanical stable non-cemented prosthesis. This is important predominantly because the need for such prostheses for younger population, and a better life quality. There are several contemporary techniques that have been used for deposition of these coatings onto the metal implant. The possibilities of atmospheric plasma-spraying for obtaining the stable HAp coatings on the 316LVM stainless steel, ordinary used as a standard material for hip implants production are presented in this paper. The coatings of a commercially available hydroxyapatite powder were plasma-sprayed onto the specimens of medical grade 316LVM stainless steel under various operating conditions. The optical microscopy was used for microstructure and porosity characterization, while coating morphology and Ca/P ratio were analyzed using SEM equipped with EDX. Coating microstructure varied from a porous to a glassy structure, depending on operating conditions applied and coating thickness. Coating porosity was determined to be at the lower required limit requested for the bone-coating intergrowth possibility, but nevertheless adhesion measurements showed good results. The Ca/P ratio was

  10. Bioactive glass in tissue engineering

    Science.gov (United States)

    Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

    2011-01-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  11. Cerâmicas bioativas: estado da arte Bioactive ceramics: state of the arts

    Directory of Open Access Journals (Sweden)

    Ângela Leão Andrade

    2006-02-01

    Full Text Available Bioactive glasses undergo corrosion with leaching of alkaline ions when exposed to body fluids. This results in the spontaneous formation of a layer of hydroxyapatite (HA, the mineral component of natural bone, which in turn can induce bone growth in vivo. This paper describes the different types of bioactive glasses, the characterization methods currently used, and the main factors that influence their bioactivity. Nucleation and crystallization, the main mechanisms involved in the formation of hydroxyapatite, Ca10(PO46(OH2, are discussed as a function of the chemical composition and the reactivity of the surface of the material. Finally, promising applications are considered.

  12. Synthesis of hydroxyapatite from biogenic wastes

    Directory of Open Access Journals (Sweden)

    Teerawat Laonapakul

    2015-09-01

    Full Text Available Hydroxyapatite (HAp is a major component of human bone, teeth and hard tissue. It is one of only a few bioactive materials. Since HAp is the most widely used ceramic biomaterial, various techniques have been developed to synthesize HAp. In recent years, the use of natural biogenic structures and materials for medical proposes has been motivated by limitations in producing synthetic materials. This article mainly focuses on the use of biogenic wastes to prepare HAp. These include bio-wastes, marine corals, eggshells, seashells and bio-membranes. In the present review, useful information about HAp preparation methodologies has been summarized for further research and development.

  13. Titanium-hydroxyapatite composites sintered at low temperature for tissue engineering: in vitro cell support and biocompatibility.

    Science.gov (United States)

    Comín, Romina; Cid, Mariana P; Grinschpun, Luciano; Oldani, Carlos; Salvatierra, Nancy A

    2017-04-26

    In clinical orthopedics, a critical problem is the bone tissue loss produced by a disease or injury. The use of composites from titanium and hydroxyapatite for biomedical applications has increased due to the resulting advantageous combination of hydroxyapatite bioactivity and favorable mechanical properties of titanium. Powder metallurgy is a simple and lower-cost method that uses powder from titanium and hydroxyapatite to obtain composites having hydroxyapatite phases in a metallic matrix. However, this method has certain limitations arising from thermal decomposition of hydroxyapatite in the titanium-hydroxyapatite system above 800°C. We obtained a composite from titanium and bovine hydroxyapatite powders sintered at 800°C and evaluated its bioactivity and cytocompatibility according to the ISO 10993 standard. Surface analysis and bioactivity of the composite was evaluated by X-ray diffraction and SEM. MTT assay was carried out to assess cytotoxicity on Vero and NIH3T3 cells. Cell morphology and cell adhesion on the composite surface were analyzed using fluorescence and SEM. We obtained a porous composite with hydroxyapatite particles well integrated in titanium matrix which presented excellent bioactivity. Our data did not reveal any toxicity of titanium-hydroxyapatite composite on Vero or NIH3T3 cells. Moreover, extracts from composite did not affect cell morphology or density. Finally, NIH3T3 cells were capable of adhering to and proliferating on the composite surface. The composite obtained displayed promising biomedical applications through the simple method of powder metallurgy. Additionally, these findings provide an in vitro proof for adequate biocompatibility of titanium-hydroxyapatite composite sintered at 800°C.

  14. Synthesis and Characterization of Novel Polycarbonate Based Polyurethane/Polymer Wrapped Hydroxyapatite Nanocomposites: Mechanical Properties, Osteoconductivity and Biocompatibility.

    Science.gov (United States)

    Selvakumar, M; Jaganathan, Saravana Kumar; Nando, Golok B; Chattopadhyay, Santanu

    2015-02-01

    The present investigation reports the preparation of two types of 2D rod-like nano-hydroxyapatite (nHA) (unmodified and Polypropylene glycol (PPG) wrapped) of varying high-aspect ratios, by modified co-precipitation methods, without any templates. These nHA were successfully introduced into novel synthesized Thermoplastic Polyurethane (TPU) matrices based on polycarbonate soft segments, by both in-situ and ex-situ techniques. Physico-mechanical properties of the in-situ prepared TPU/nHA nanocomposites were found to be superior compared to the ex-situ counterparts, and pristine nHA reinforced TPU. Improved biocompatibility of the prepared nanocomposites was confirmed by MTT assays using osteoblast-like MG63 cells. Cell proliferation was evident over an extended period. Osteoconductivity of the nanocomposites was observed by successful formation of an apatite layer on the surface of the samples, after immersion into simulated body fluid (SBF). Prothrombin time (PT) and activated partial thromboplastin time (APTT), as calculated from coagulation assays, displayed an increase in the clotting time, particularly for the PPG-wrapped nHA nanocomposites, prepared through the in-situ technique. Only 0.3% of hemolysis was observed for the in-situ prepared nanocomposites, which establishes the antithrombotic property of the material. The key parameters for enhancing the technical properties and biocompatibility of the nanocomposites are: the interfacial adhesion parameter (B(σy)), the polymer-filler affinity, the aspect ratio of filler and non-covalent modifications, and the state of dispersion. Thus, the novel TPU/polymer wrapped nHA nanocomposites have great potential for biomedical applications, in particular for vascular prostheses, cardiovascular implants, scaffolds, and soft and hard tissues implants.

  15. Luminescent, Fire-Resistant, and Water-Proof Ultralong Hydroxyapatite Nanowire-Based Paper for Multimode Anticounterfeiting Applications.

    Science.gov (United States)

    Yang, Ri-Long; Zhu, Ying-Jie; Chen, Fei-Fei; Dong, Li-Ying; Xiong, Zhi-Chao

    2017-08-02

    Counterfeiting of valuable certificates, documents, and banknotes is a serious issue worldwide. As a result, the need for developing novel anticounterfeiting materials is greatly increasing. Herein, we report a new kind of ultralong hydroxyapatite nanowire (HAPNW)-based paper with luminescence, fire resistance, and waterproofness properties that may be exploited for anticounterfeiting applications. In this work, lanthanide-ion-doped HAPNWs (HAPNW:Ln 3+ ) with lengths over 100 μm have been synthesized and used as a raw material to fabricating a free-standing luminescent, fire-resistant, water-proof paper through a simple vacuum filtration process. It is interesting to find that the luminescence intensity, structure, and morphology of HAPNW:Ln 3+ highly depend on the experimental conditions. The as-prepared HAPNW:Ln 3+ paper has a unique combination of properties, such as high flexibility, good processability, writing and printing abilities, luminescence, tunable emission color, waterproofness, and fire resistance. In addition, a well-designed pattern can be embedded in the paper that is invisible under ambient light but viewable as a luminescent color under ultraviolet light. Moreover, the HAPNW:Ln 3+ paper can be well-preserved without any damage after being burned by fire or soaked in water. The unique combination of luminescence, fire resistance, and waterproofness properties and the nanowire structure of the as-prepared HAPNW:Ln 3+ paper may be exploited toward developing a new kind of multimode anticounterfeiting technology for various high-level security antiforgery applications, such as in making forgery-proof documents, certificates, labels, and tags and in packaging.

  16. Evaluation of bioactivity in vitro of endodontic calcium aluminate cement

    International Nuclear Information System (INIS)

    Oliveira, I.R.; Andrade, T.L.; Santos, G.L.; Pandolfelli, V.C.

    2011-01-01

    Bioactivity is referred to as the capacity of a material to develop a stable bond with living tissue via the deposition of hydroxyapatite. Materials which exhibit this property can be used to repair diseased or damaged bone tissue and can be designed to remain in situ indefinitely. An indication of bioactivity can be obtained by the formation of a hydroxyapatite layer on the surface of a substrate in simulated body fluids (SBF) in vitro. Therefore, set samples of calcium aluminate endodontic cement were maintained in contact with SBF solutions (Kokubo and Rigo) and their surfaces were later evaluated by means of SEM, EDX and DRX. Measurements of pH and ionic conductivity were also carried out for SBF solutions in contact with set samples of endodontic cement. The ideal conditions of precipitation were obtained in SBF Rigo been observed a surface layer with spherical morphology characteristic of stoichiometric hydroxyapatite.(author)

  17. Combined genetic and bioactivity-based prioritization leads to the isolation of an endophyte-derived antimycobacterial compound.

    Science.gov (United States)

    Alvin, A; Kalaitzis, J A; Sasia, B; Neilan, B A

    2016-05-01

    To initiate a genetic and bioactivity-based screening programme of culturable endophytes to identify micro-organisms capable of producing bioactive polyketides and peptides. Fungal endophytes were isolated from flowers, leaves and roots of Rhoeo spathacea, revealing a community consisting of Colletotrichum sp., Fusarium sp., Guignardia sp., Phomopsis sp., Phoma sp. and Microdochium sp. Genetic screening showed that all isolates had polyketide synthase (PKS) genes and most had nonribosomal peptide synthetase (NRPS) genes. Ethyl acetate extracts of the fungal isolates exhibited antiproliferative activity against at least one of the seven bacterial and mycobacterial test strains. Nuclear Magnetic Resonance -guided fractionation of the crude extract from a Fusarium sp. strain which exhibited strong antiproliferative activity against Mycobacterium tuberculosis resulted in the isolation of the polyketide javanicin. This compound was active against Myco. tuberculosis (MIC = 25 μg ml(-1)) and Mycobacterium phlei (MIC = 50 μg ml(-1)). The medicinal plant R. spathacea hosts a variety of fungal endophytes capable of producing antibacterial and antimycobacterial compounds. There is a positive correlation between the presence of PKS and/or NRPS encoding genes in endophytes and the bioactivity of their respective organic extracts. This is the first report on the fungal endophytic diversity of R. spathacea, and the isolation of an antimycobacterial compound from the plant which has been traditionally used for the treatment of tuberculosis symptoms. © 2016 The Society for Applied Microbiology.

  18. Bio-Activity and Dereplication-Based Discovery of Ophiobolins and Other Fungal Secondary Metabolites Targeting Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Tanja Thorskov Bladt

    2013-11-01

    Full Text Available The purpose of this study was to identify and characterize fungal natural products (NPs with in vitro bioactivity towards leukemia cells. We based our screening on a combined analytical and bio-guided approach of LC-DAD-HRMS dereplication, explorative solid-phase extraction (E-SPE, and a co-culture platform of CLL and stromal cells. A total of 289 fungal extracts were screened and we tracked the activity to single compounds in seven of the most active extracts. The novel ophiobolin U was isolated together with the known ophiobolins C, H, K as well as 6-epiophiobolins G, K and N from three fungal strains in the Aspergillus section Usti. Ophiobolins A, B, C and K displayed bioactivity towards leukemia cells with induction of apoptosis at nanomolar concentrations. The remaining ophiobolins were mainly inactive or only slightly active at micromolar concentrations. Dereplication of those ophiobolin derivatives possessing different activity in combination with structural analysis allowed a correlation of the chemical structure and conformation with the extent of bioactivity, identifying the hydroxy group at C3 and an aldehyde at C21, as well as the A/B-cis ring structure, as indispensible for the strong activity of the ophiobolins. The known compounds penicillic acid, viridicatumtoxin, calbistrin A, brefeldin A, emestrin A, and neosolaniol monoacetate were identified from the extracts and also found generally cytotoxic.

  19. Different properties exhibited on the two typical crystal faces of hydroxyapatite in a simulated body environment

    International Nuclear Information System (INIS)

    Hagio, T; Iwai, K; Tanase, T; Akiyama, J; Asai, S

    2009-01-01

    Hydroxyapatite is a main mineral constituent of hard tissues and is extensively used as a biomaterial in the medical field. Hydroxyapatite exhibits anisotropic chemical properties on its two typical crystal faces, the a-face and c-face, due to its hexagonal crystal structure. In polycrystalline bodies, such anisotropy can be enhanced by controlling the crystal orientation. Hydroxyapatite nanocrystals that constitute long bones also form a crystal oriented structure. Therefore, clarification of the difference between the properties of a-face and c-face in hydroxyapatite using in vitro experiments is useful to understand the structure and function of actual hard tissues. Hydroxyapatite ceramics with controlled crystal orientation were prepared by a slip casting method under application of a magnetic field. The fabricated hydroxyapatite ceramics had surfaces consisting mainly of a-face, or otherwise c-face hydroxyapatite. These hydroxyapatite ceramics were immersed into simulated body fluids to investigate the difference in bioactivity. The precipitation behavior observed on the surface of each hydroxyapatite ceramic was different. The thickness of the precipitate was increased and formed earlier on the HAp c-face compared to that on the a-face.

  20. Different properties exhibited on the two typical crystal faces of hydroxyapatite in a simulated body environment

    Energy Technology Data Exchange (ETDEWEB)

    Hagio, T; Iwai, K [Department of Materials, Physics and Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 (Japan); Tanase, T [Toho Gas Corporation, 19-18 Sakurada-cho, Atsuta-ku, Nagoya, 456-8511 (Japan); Akiyama, J [Institute for Molecular Science, National Institute of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585 (Japan); Asai, S [Innovation Plaza Tokai Japan Science and Technology Agency, 23-1 Ahara-cho, Minami-ku, Nagoya, 457-0063 (Japan)], E-mail: hagio.takeshi@h.mbox.nagoya-u.ac.jp

    2009-03-01

    Hydroxyapatite is a main mineral constituent of hard tissues and is extensively used as a biomaterial in the medical field. Hydroxyapatite exhibits anisotropic chemical properties on its two typical crystal faces, the a-face and c-face, due to its hexagonal crystal structure. In polycrystalline bodies, such anisotropy can be enhanced by controlling the crystal orientation. Hydroxyapatite nanocrystals that constitute long bones also form a crystal oriented structure. Therefore, clarification of the difference between the properties of a-face and c-face in hydroxyapatite using in vitro experiments is useful to understand the structure and function of actual hard tissues. Hydroxyapatite ceramics with controlled crystal orientation were prepared by a slip casting method under application of a magnetic field. The fabricated hydroxyapatite ceramics had surfaces consisting mainly of a-face, or otherwise c-face hydroxyapatite. These hydroxyapatite ceramics were immersed into simulated body fluids to investigate the difference in bioactivity. The precipitation behavior observed on the surface of each hydroxyapatite ceramic was different. The thickness of the precipitate was increased and formed earlier on the HAp c-face compared to that on the a-face.

  1. In vitro characterization of hydroxyapatite layers deposited by APS and HVOF thermal spraying methods

    Directory of Open Access Journals (Sweden)

    Radu Alexandru Roşu

    2012-03-01

    Full Text Available Titanium alloys are successfully used in medicine as implants due to their high mechanical properties and good biocompatibility. To improve implant osseointegration of titanium alloys, they are covered with hydroxyapatite because of its bioactive properties. Coating the implants with hydroxyapatite by thermal spraying, due to the temperatures developed during the deposition process, the structure can be degraded, leading to formation of secondary phases, such as TCP, TT CP, CaO. The paper presents the experimental results of hydroxyapatite layers deposition by two thermal spraying methods: Atmospheric Plasma Spraying (APS and High Velocity Oxy-Fuel (HVOF. The microstructure of the deposited layers is characterized by X-ray diffraction analysis and electronic microscopy. The bioactivity of the hydroxyapatite layers was investigated in Simulated Body Fluid (SBF by immersing the covered samples deposited by the two thermal spraying methods. In both cases the coatings did not present defects as cracks or microcracks. X-ray diffraction performed on hydroxyapatite deposited layers shows that the structure was strongly influenced by plasma jet temperature, the structure consisting mainly of TCP (Ca3PO42. The samples deposited by HVO F after immersing in SBF lead to formation of biological hydroxyapatite, certifying the good bioactivity of the coatings.

  2. Diopside-Fluorapatite-Wollastonite Based Bioactive Glasses and Glass-ceramics =

    Science.gov (United States)

    Kansal, Ishu

    Bioactive glasses and glass-ceramics are a class of biomaterials which elicit special response on their surface when in contact with biological fluids, leading to strong bonding to living tissue. This particular trait along with good sintering ability and high mechanical strength make them ideal materials for scaffold fabrication. The work presented in this thesis is directed towards understanding the composition-structure-property relationships in potentially bioactive glasses designed in CaO-MgO-P2O5-SiO2-F system, in some cases with added Na2O. The main emphasis has been on unearthing the influence of glass composition on molecular structure, sintering ability and bioactivity of phosphosilicate glasses. The parent glass compositions have been designed in the primary crystallization field of the pseudo-ternary system of diopside (CaO•MgO•2SiO2) - fluorapatite (9CaO•3P2O5•CaF2) - wollastonite (CaO•SiO2), followed by studying the impact of compositional variations on the structure-property relationships and sintering ability of these glasses. All the glasses investigated in this work have been synthesized via melt-quenching route and have been characterized for their molecular structure, sintering ability, chemical degradation and bioactivity using wide array of experimental tools and techniques. It has been shown that in all investigated glass compositions the silicate network was mainly dominated by Q2 units while phosphate in all the glasses was found to be coordinated in orthophosphate environment. The glass compositions designed in alkali-free region of diopside - fluorapatite system demonstrated excellent sintering ability and good bioactivity in order to qualify them as potential materials for scaffold fabrication while alkali-rich bioactive glasses not only hinder the densification during sintering but also induce cytotoxicity in vitro, thus, are not ideal candidates for in vitro tissue engineering. One of our bioglass compositions with low sodium

  3. Bioactive Structure of Membrane Lipids and Natural Products Elucidated by a Chemistry-Based Approach.

    Science.gov (United States)

    Murata, Michio; Sugiyama, Shigeru; Matsuoka, Shigeru; Matsumori, Nobuaki

    2015-08-01

    Determining the bioactive structure of membrane lipids is a new concept, which aims to examine the functions of lipids with respect to their three-dimensional structures. As lipids are dynamic by nature, their "structure" does not refer solely to a static picture but also to the local and global motions of the lipid molecules. We consider that interactions with lipids, which are completely defined by their structures, are controlled by the chemical, functional, and conformational matching between lipids and between lipid and protein. In this review, we describe recent advances in understanding the bioactive structures of membrane lipids bound to proteins and related molecules, including some of our recent results. By examining recent works on lipid-raft-related molecules, lipid-protein interactions, and membrane-active natural products, we discuss current perspectives on membrane structural biology. © 2015 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Antimicrobial activity of different hydroxyapatites

    International Nuclear Information System (INIS)

    Feitosa, G.T.; Santos, M.V.B.; Barreto, H.M.; Osorio, L.R.; Osajima, J.A.; Silva Filho, E.C. da

    2014-01-01

    Among the applications of ceramics in the technological context, hydroxyapatite (HAp) stands out in the scientific community due to chemical biocompatibility and molecular similarity to the structures of bone and dental tissues. Such features are added to the antimicrobial properties that this brings. This work aimed at the synthesis of hydroxyapatite by two different routes, hydrothermal (HD HAp) and co-precipitation (CP HAp), as well as verification of the antimicrobial properties of these through direct contact of the powders synthesized tests with Staphylococcus aureus (SA10) and Escherichia coli (EC7) bacteria. The materials was characterized by XRD, Raman and TEM, and Antimicrobial tests showed inhibitory efficacy of 97% and 9.5% of CP HAp for SA10 and EC7, respectively. The HD HAp had inhibitory effect of 95% and 0% for EC7 and SA10, respectively. The inhibitory effect on SA10 is based on the hydrophilicity that the material possesses. (author)

  5. Synthesis and Characterization of Nano-Hydroxyapatite/mPEG-b-PCL Composite Coating on Nitinol Alloy

    Directory of Open Access Journals (Sweden)

    Mohamadreza Etminanfar

    2017-12-01

    Full Text Available In this study the bioactivity of hydroxyapatite/poly(ε-caprolactone–poly(ethylene glycol bilayer coatings on Nitinol superelastic alloy was investigated. The surface of Nitinol alloy was activated by a thermo-chemical treatment and hydroxyapatite coating was electrodeposited on the alloy, followed by applying the polymer coating. The surface morphology of coatings was studied using FE-SEM and SEM. The data revealed that the hydroxyapatite coating is composed of one-dimensional nano sized flakes and the polymer coating is uniformly covered the sublayer. Also, High resolution TEM studies on the hydroxyapatite samples revealed that each flake contains nano-crystalline grains with a diameter of about 15 nm. The hydroxyapatite monolayer coating was rapidly covered by calcium phosphate crystals (Ca/P=1.7 after immersion in simulated body fluid confirming the bioactivity of the nanostructured flakes. However, the flakes were weak against applied external forces because of their ultra-fine thickness. Scratch test was applied on hydroxyapatite/polymer coating to evaluate delamination of the coating from substrate. It was shown that, the polymer coating has a great influence on toughening the hydroxyapatite coating. To assess the degradation effect of the polymer layer on hydroxyapatite coating, samples were immersed in phosphate-buffered saline at 37 ᵒC. SEM studies on the samples revealed that the beneath layer of hydroxyapatite appears after 72 h without any visible change in morphology. It seems that, application of a biodegradable polymer film on the nanostructured hydroxyapatite coating is a good way to support the coating during implantation processes

  6. Plants and mushrooms as sources of bio-based food coloring, preserving and bioactive agents

    OpenAIRE

    Ferreira, Isabel C.F.R.

    2018-01-01

    Food additives have been used for thousands of years to enhance food properties, safety and appearance. Nevertheless, several of the worldwide used artificial additives have been related to potential toxic and allergenic effects to the consumers, which has been justifying the growing interest in additives of natural origin that provide colouring, preserving, and bioactive properties to foodstuff without hazardous effects [1]. In this context, several plants and mushrooms have been...

  7. Fabrication and mechanical evaluation of hydroxyapatite/oxide nano-composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: Kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, El-Behoos St., Cairo (Egypt); Beherei, Hanan H. [Biomaterials Dept., National Research Centre, El-Behoos St., Cairo (Egypt); Physics Dept., Faculty of Science, El-Taif University (Saudi Arabia); El Bassyouni, Gehan T. [Biomaterials Dept., National Research Centre, El-Behoos St., Cairo (Egypt); Medical Physics Dept., Faculty of Medicine, El-Taif University (Saudi Arabia); El Mahallawy, Nahed [Design and Production Engineering Department, Faculty of Engineering, Ain Shams University on secondment to the German University in Cairo (Egypt)

    2013-10-15

    In the current study, the semiconducting metal oxides such as nano-ZnO and SiO{sub 2} powders were prepared via sol–gel technique and conducted on nano-hydroxyapatite (nHA) which was synthesized by chemical precipitation. The properties of fabricated nano-structured composites containing different ratios of HA, ZnO and SiO{sub 2} were examined using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The effect of the variation of ratios between the three components on mechanical, microstructure and in-vitro properties was assessed to explore the possibility of enhancing these properties. The results proved that the mechanical properties exhibited an increment with increasing the ZnO content at the extent of HA. In-vitro study proved the formation and nucleation of apatite onto the surface of the fabricated composites after one week of immersion. It is concluded that HA composites containing SiO{sub 2} or SiO{sub 2}/ZnO content had a suitable mechanical properties and ability to form apatite particles onto the composite surface. Based on bioactivity behavior, Si-HA is more bioactive than pure hydroxyapatite and nano-arrangements will provide an interface for better bone formation. Therefore, these nano-composites will be promising as bone substitutes especially in load bearing sites. - Graphical abstract: Nano-structures of (a) HA, (b) ZnO and (c) SiO{sub 2} powders. Highlights: • The nano-structured composites containing different ratios of HA, ZnO and SiO{sub 2} were prepared. • ZnO helps improve the mechanical properties of HA composites. • SiO{sub 2} helps improve the bioactivity of HA composites.

  8. Seaweed Bioactivity

    DEFF Research Database (Denmark)

    Zaharudin, Nazikussabah Binti

    . In conclusion, two brown seaweeds, Laminaria digitata and Undaria pinnatifida, inhibited α-amylase and α-glucosidase activities due to their content of several bioactive components with a potential use for future functional foods. Their effects on the postprandial insulin response and the in vitro findings...

  9. Hydroxyapatites and europium(III) doped hydroxyapatites as a carrier of silver nanoparticles and their antimicrobial activity.

    Science.gov (United States)

    Wiglusz, Rafal J; Kedziora, Anna; Lukowiak, Anna; Doroszkiewicz, Wlodzimierz; Strek, Wieslaw

    2012-08-01

    Hydroxyapatites (Ca10(PO4)6(OH)2 and Eu3+:Ca10(PO4)6(OH)2) were synthesized by aqueous synthesis route. Hydroxyapatites were impregnated with silver ions that were subsequently reduced. XRD, TEM, and SAED measurements were used in order to determine the crystal structure and morphology of the final products. The results showed the well crystallized hydroxyapatite grains with diameter of about 35 nm and with silver nanoparticles on their surface. The antimicrobial activity of the nanoparticles against: Staphylococcus aureus ATCC 6538 as model of the Gram-positive bacteria, Escherichia coli ATCC 11229, and Klebsiella pneumoniae ATCC 4352 as model of Gram-negative bacteria, were shown with the best activity against K. pneumoniae. These nanocomposite powders can be a promising antimicrobial agent and a fluorescent material for biodetection due to their optical and bioactive properties.

  10. Whiskers and fibers of hydroxyapatite; Whiskers e fibras de hidroxiapatita

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, G.B.C.; Motisuke, M.; Zavaglia, C.A.C., E-mail: guicardoso@fem.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Materiais; Arruda, A.C.F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Petroleo

    2009-07-01

    Hydroxyapatite is a bioactive ceramic, which acts in tissue engineering by attracting bone cells. Occasionally it can be used as a biocompatible reinforcement. The mechanical role of this biomaterial can be defined depending of some characteristics analyzed by scanning electron microscope and X ray power diffraction. It can be classified in whiskers and fibers; each one has their own properties, which were discussed in this work. For its use as reinforcement it is necessary matrix with specific characteristics. (author)

  11. Microwave annealing for preparation of crystalline hydroxyapatite thin films

    CSIR Research Space (South Africa)

    Adams, D

    2006-11-01

    Full Text Available Hydroxyapatite (HA) is widely preferred as the bio- material coating of choice in both dental and ortho- paedic implants due to its favourable osteo-conductive and bioactive properties [1]. Sol–gel synthesis of HA offers a viable alternative to the high... viable option because it is performed in air. Microwave heating differs fundamentally from conventional heating in that heat energy is generated from within the material instead of originating from D. Adams (&) Department of Physics, University...

  12. A comparative study of hydroxyapatite nanoparticles synthesized by different routes

    OpenAIRE

    Paz, Adrian; Guadarrama, Dainelys; López, Mónica; E. González, Jesús; Brizuela, Nayrim; Aragón, Javier

    2012-01-01

    In this study, bioactive hydroxyapatite nanoparticles were prepared by two different methods: wet chemical precipitation and biomimetic precipitation. The aim was to evaluate the morphology, particle-size, crystallinity and phases of the powders obtained by traditional wet chemical precipitation and the novel biomimetic precipitation using a supersaturated calcium solution. The nanoparticles were investigated by transmission electron microscopy, Fourier transform infrared spectroscopy and X-r...

  13. Electrophoretic deposition of mesoporous bioactive glass on glass-ceramic foam scaffolds for bone tissue engineering.

    Science.gov (United States)

    Fiorilli, Sonia; Baino, Francesco; Cauda, Valentina; Crepaldi, Marco; Vitale-Brovarone, Chiara; Demarchi, Danilo; Onida, Barbara

    2015-01-01

    In this work, the coating of 3-D foam-like glass-ceramic scaffolds with a bioactive mesoporous glass (MBG) was investigated. The starting scaffolds, based on a non-commercial silicate glass, were fabricated by the polymer sponge replica technique followed by sintering; then, electrophoretic deposition (EPD) was applied to deposit a MBG layer on the scaffold struts. EPD was also compared with other techniques (dipping and direct in situ gelation) and it was shown to lead to the most promising results. The scaffold pore structure was maintained after the MBG coating by EPD, as assessed by SEM and micro-CT. In vitro bioactivity of the scaffolds was assessed by immersion in simulated body fluid and subsequent evaluation of hydroxyapatite (HA) formation. The deposition of a MBG coating can be a smart strategy to impart bioactive properties to the scaffold, allowing the formation of nano-structured HA agglomerates within 48 h from immersion, which does not occur on uncoated scaffold surfaces. The mechanical properties of the scaffold do not vary after the EPD (compressive strength ~19 MPa, fracture energy ~1.2 × 10(6) J m(-3)) and suggest the suitability of the prepared highly bioactive constructs as bone tissue engineering implants for load-bearing applications.

  14. Synthesis of Hydroxyapatite using Precipitated Calcium Carbonate (PCC) from Limestones

    Science.gov (United States)

    Wardhani, Sri; Isnaini Azkiya, Noor; Triandi Tjahjanto, Rachmat

    2018-01-01

    Hydroxyapatite (HAp) is a material that widely applied in bone and teeth implant due to its biocompatibility and bioactivity. This material can be prepared from PCC by precipitation method using CaO and H3PO4 in ethanol. In this work, variations of phosphoric acid amount and aging time were investigated. The synthesized HAp was characterized by FT-IR, AAS, UV-Vis Spectrophotometer, PSA, SEM, and powder XRD. The results showed that the high concentration of calcium in PCC gives better yields in which PCC obtained from carbonation method has higher yield than that of caustic soda method. The determination of optimum phosphoric acid addition based on targeted Ca/P ratio (1.67) from HAp was obtained on the addition of 0.1271 mol phosphoric acid with Ca/P ratio of 1.66. The aging time gave significant effect to the particle size of synthesised HAp. The smallest particle size was obtained in aging time for 48 hours as high as 49.25 μm. FTIR spectra of the synthesized HAp show the presence of hydroxyl (-OH) group at 3438.8 cm-1, PO4 3- at 557.39 and 1035.7 cm-1, and CaO at 1413.72 cm-1. The synthesized HAp forms agglomeration solid based on the SEM analysis. The powder XRD data shows three highest peaks at 2θ i.e. 27.8296; 31.1037; and 34.3578 which corresponds to β-TCP (tricalcium phosphate) in accordance with JCPDS no.09-0169. The characteristic 2θ peak of hydroxyapatite with low intensity is observed from the synthesized HAp refer to the JCPDS data no. 09-0432.

  15. (1)H NMR-based metabonomics revealed protective effect of Naodesheng bioactive extract on ischemic stroke rats.

    Science.gov (United States)

    Luo, Lan; Zhen, Lifeng; Xu, Yatao; Yang, Yongxia; Feng, Suxiang; Wang, Shumei; Liang, Shengwang

    2016-06-20

    Stroke is a leading cause of death and disability in the world. However, current therapies are limited. Naodesheng, a widely used traditional Chinese medicine prescription, has shown a good clinical curative effect on ischemic stroke. Also, Naodesheng has been suggested to have neuroprotective effect on focal cerebral ischemia rats, but the underlying molecular mechanism remains unclear. The present study was designed to evaluate the effect of Naodesheng bioactive extract on the metabolic changes in brain tissue, plasma and urine induced by cerebral ischemia perfusion injury, and explore the possible metabolic mechanisms by using a (1)H NMR-based metabonomics approach. A middle cerebral artery occlusion rat model was established and confirmed by the experiments of neurobehavioral abnormality evaluation, brain tissue TTC staining and pathological examination. The metabolic changes in brain tissue, plasma and urine were then assessed by a (1)H NMR technique combined with multivariate statistical analysis method. These NMR data showed that cerebral ischemia reperfusion induced great metabolic disorders in brain tissue, plasma and urine metabolisms. However, Naodesheng bioactive extract could reverse most of the imbalanced metabolites. Meanwhile, it was found that both the medium and high dosages of Naodesheng bioactive extract were more effective on the metabolic changes than the low dosage, consistent with histopathological assessments. These results revealed that Naodesheng had protective effect on ischemic stroke rats and the underlying mechanisms involved multiple metabolic pathways, including energy metabolism, amino acid metabolism, oxidative stress and inflammatory injury. The present study could provide evidence that metabonomics revealed its capacity to evaluate the holistic efficacy of traditional Chinese medicine and explore the underlying mechanisms. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Alkali-free bioactive glasses for bone regeneration =

    Science.gov (United States)

    Kapoor, Saurabh

    Bioactive glasses and glass-ceramics are a class of third generation biomaterials which elicit a special response on their surface when in contact with biological fluids, leading to strong bonding to living tissues. The purpose of the present study was to develop diopside based alkali-free bioactive glasses in order to achieve good sintering behaviour, high bioactivity, and a dissolution/ degradation rates compatible with the target applications in bone regeneration and tissue engineering. Another aim was to understand the structure-property relationships in the investigated bioactive glasses. In this quest, various glass compositions within the Diopside (CaMgSi2O6) - Fluorapatite (Ca5(PO4)3F) - Tricalcium phosphate (3CaO•P2O5) system have been investigated. All the glasses were prepared by melt-quenching technique and characterized by a wide array of complementary characterization techniques. The glass-ceramics were produced by sintering of glass powders compacts followed by a suitable heat treatment to promote the nucleation and crystallization phenomena. Furthermore, selected parent glass compositions were doped with several functional ions and an attempt to understand their effects on the glass structure, sintering ability and on the in vitro bio-degradation and biomineralization behaviours of the glasses was made. The effects of the same variables on the devitrification (nucleation and crystallization) behaviour of glasses to form bioactive glass-ceramics were also investigated. Some of the glasses exhibited high bio-mineralization rates, expressed by the formation of a surface hydroxyapatite layer within 1-12 h of immersion in a simulated body fluid (SBF) solution. All the glasses showed relatively lower degradation rates in comparison to that of 45S5 Bioglass. Some of the glasses showed very good in vitro behaviour and the glasses co-doped with zinc and strontium showed an in vitro dose dependent behaviour. The as-designed bioactive glasses and glass

  17. Fracture toughness of heat cured denture base acrylic resin modified with Chlorhexidine and Fluconazole as bioactive compounds.

    Science.gov (United States)

    Al-Haddad, Alaa; Vahid Roudsari, Reza; Satterthwaite, Julian D

    2014-02-01

    This study investigated the impact of incorporating Chlorhexidine and Fluconazole as bioactive compounds on the fracture toughness of conventional heat cured denture base acrylic resin material (PMMA). 30 single edge-notched (SEN) samples were prepared and divided into three groups. 10% (mass) Chlorhexidine and 10% (mass) Diflucan powder (4.5% mass Fluconazole) were added to heat cured PMMA respectively to create the two study groups. A third group of conventional heat cured PMMA was prepared as the control group. Fracture toughness (3-point bending test) was carried out for each sample and critical force (Fc) and critical stress intensity factor (KIC) values measured. Data were subject to parametric statistical analysis using one-way ANOVA and Post hoc Bonferroni test (p=0.05). Fluconazole had no significant effect on the fracture toughness of the PMMA while Chlorhexidine significantly reduced the KIC and therefore affected the fracture toughness. When considering addition of a bioactive material to PMMA acrylic, Chlorhexidine will result in reduced fracture toughness of the acrylic base while Fluconazole has no effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Antimicrobial coatings based on zinc oxide and orange oil for improved bioactive wound dressings and other applications.

    Science.gov (United States)

    Rădulescu, Marius; Andronescu, Ecaterina; Cirja, Andreea; Holban, Alina Maria; Mogoantă, LaurenŢiu; Bălşeanu, Tudor Adrian; Cătălin, Bogdan; Neagu, Tiberiu Paul; Lascăr, Ioan; Florea, Denisa Alexandra; Grumezescu, Alexandru Mihai; Ciubuca, Bianca; Lazăr, Veronica; Chifiriuc, Mariana Carmen; Bolocan, Alexandra

    2016-01-01

    This work presents a novel nano-modified coating for wound dressings and other medical devices with anti-infective properties, based on functionalized zinc oxide nanostructures and orange oil (ZnO@OO). The obtained nanosurfaces were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), differential thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The obtained nanocomposite coatings exhibited an antimicrobial activity superior to bare ZnO nanoparticles (NPs) and to the control antibiotic against Staphylococcus aureus and Escherichia coli, as revealed by the lower minimal inhibitory concentration values. For the quantitative measurement of biofilm-embedded microbial cells, a culture-based, viable cell count method was used. The coated wound dressings proved to be more resistant to S. aureus microbial colonization and biofilm formation compared to the uncoated controls. These results, correlated with the good in vivo biodistribution open new directions for the design of nanostructured bioactive coating and surfaces, which can find applications in the medical field, for obtaining improved bioactive wound dressings and prosthetic devices, but also in food packaging and cosmetic industry.

  19. Mechanical Behavior of Nanostructured Hybrids Based on Poly(Vinyl Alcohol/Bioactive Glass Reinforced with Functionalized Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    H. S. Mansur

    2012-01-01

    Full Text Available This study reports the synthesis and characterization of novel tridimensional porous hybrids based on PVA combined with bioactive glass and reinforced by chemically functionalized carbon nanotubes (CNT for potential use in bone tissue engineering. The functionalization of CNT was performed by introducing carboxylic groups in multiwall nanotubes. This process aimed at enhancing the affinity of CNTs with the water-soluble PVA polymer derived by the hydrogen bonds formed among alcohol (PVA and carboxylic groups (CNT–COOH. In the sequence, the CNT–COOH (0.25 wt% were used as the nanostructure modifier for the hybrid system based on PVA associated with the bioactive glass (BaG. The mechanical properties of the nanostructured hybrids reinforced with CNT–COOH were evaluated by axial compression tests, and they were compared to reference hybrid. The averaged yield stresses of macroporous hybrids were (2.3 ± 0.9 and (4.4 ± 1.0 MPa for the reference and the CNT reinforced materials, respectively. Moreover, yield strain and Young's modulus were significantly enhanced by about 30% for the CNT–COOH hybrids. Hence, as far as the mechanical properties are concerned, the results have clearly showed the feasibility of utilizing these new hybrids reinforced with functionalized CNT in repairing cancellous bone tissues.

  20. Numerical investigations on the osseointegration of uncemented endoprostheses based on bio-active interface theory

    Science.gov (United States)

    Lutz, André; Nackenhorst, Udo

    2012-09-01

    In order to simulate the osseointegration of bone implants, a bio-active interface theory is necessary. The thin bone-implant interface layer is described by the Drucker-Prager plasticity model. The formulation of bone mineral density depends on the local mechanical environment. For the simulation of the osseointegration of bone implants a bio-active interface theory is suggested. A thin bone-implant interface layer is described by a Drucker-Prager plasticity model. An evolution rule for the bone mineral density is formulated in dependency of the local mechanical environment. The time dependent ingrowth is modeled by a hardening rule which modifies the Drucker-Prager yield-surface cone in the principle stress state in dependency of the local bone mineral density. The osseointegration process is limited by the violation of a so called micromotion threshold. This relative motion in the implant-bone interface is computed by dynamic loads of daily motion activity. For parameter studies on detailed 3D models model reduction techniques are introduced. The applicability is demonstrated on a hip-joint prosthesis which is in clinical usage.

  1. Highly-Bioreactive Silica-Based Mesoporous Bioactive Glasses Enriched with Gallium(III

    Directory of Open Access Journals (Sweden)

    Sandra Sanchez-Salcedo

    2018-03-01

    Full Text Available Beneficial effects in bone cell growth and antibacterial action are currently attributed to Ga3+ ions. Thus, they can be used to upgrade mesoporous bioactive glasses (MBGs, investigated for tissue engineering, whenever they released therapeutic amounts of gallium ions to the surrounding medium. Three gallium-enriched MBGs with composition (in mol % xSiO2–yCaO–zP2O5–5Ga2O3, being x = 70, y = 15, z = 10 for Ga_1; x = 80, y = 12, z = 3 for Ga_2; and x = 80, y = 15, z = 0 for Ga_3, were investigated and compared with the gallium-free 80SiO2–15CaO–5P2O5 MBG (B. 29Si and 31P MAS NMR analyses indicated that Ga3+ acts as network modifier in the glass regions with higher polymerization degree and as network former in the zones with high concentration of classical modifiers (Ca2+ ions. Ga_1 and Ga_2 exhibited a quick in vitro bioactive response because they were coated by an apatite-like layer after 1 and 3 days in simulated body fluid. Although we have not conducted biological tests in this paper (cells or bacteria, Ga_1 released high but non-cytotoxic amounts of Ga3+ ions in Todd Hewitt Broth culture medium that were 140 times higher than the IC90 of Pseudomonas aeruginosa bacteria, demonstrating its potential for tissue engineering applications.

  2. Risk-based high-throughput chemical screening and prioritization using exposure models and in vitro bioactivity assays

    International Nuclear Information System (INIS)

    Shin, Hyeong-Moo; Ernstoff, Alexi; Csiszar, Susan A.

    2015-01-01

    We present a risk-based high-throughput screening (HTS) method to identify chemicals for potential health concerns or for which additional information is needed. The method is applied to 180 organic chemicals as a case study. We first obtain information on how the chemical is used and identify relevant use scenarios (e.g., dermal application, indoor emissions). For each chemical and use scenario, exposure models are then used to calculate a chemical intake fraction, or a product intake fraction, accounting for chemical properties and the exposed population. We then combine these intake fractions with use scenario-specific estimates of chemical quantity to calculate daily intake rates (iR; mg/kg/day). These intake rates are compared to oral equivalent doses (OED; mg/kg/day), calculated from a suite of ToxCast in vitro bioactivity assays using in vitro-to-in vivo extrapolation and reverse dosimetry. Bioactivity quotients (BQs) are calculated as iR/OED to obtain estimates of potential impact associated with each relevant use scenario. Of the 180 chemicals considered, 38 had maximum iRs exceeding minimum OEDs (i.e., BQs > 1). For most of these compounds, exposures are associated with direct intake, food/oral contact, or dermal exposure. The method provides high-throughput estimates of exposure and important input for decision makers to identify chemicals of concern for further evaluation with additional information or more refined models

  3. Hydrolysis and Sulfation Pattern Effects on Release of Bioactive Bone Morphogenetic Protein-2 from Heparin-Based Microparticles.

    Science.gov (United States)

    Tellier, Liane E; Miller, Tobias; McDevitt, Todd C; Temenoff, Johnna S

    2015-10-28

    Glycosaminoglycans (GAGs) such as heparin are promising materials for growth factor delivery due to their ability to efficiently bind positively charged growth factors including bone morphogenetic protein-2 (BMP-2) through their negatively charged sulfate groups. Therefore, the goal of this study was to examine BMP-2 release from heparin-based microparticles (MPs) after first, incorporating a hydrolytically degradable crosslinker and varying heparin content within MPs to alter MP degradation and second, altering the sulfation pattern of heparin within MPs to vary BMP-2 binding and release. Using varied MP formulations, it was found that the time course of MP degradation for 1 wt% heparin MPs was ~4 days slower than 10 wt% heparin MPs, indicating that MP degradation was dependent on heparin content. After incubating 100 ng BMP-2 with 0.1 mg MPs, most MP formulations loaded BMP-2 with ~50% efficiency and significantly more BMP-2 release (60% of loaded BMP-2) was observed from more sulfated heparin MPs (MPs with ~100% and 80% of native sulfation). Similarly, BMP-2 bioactivity in more sulfated heparin MP groups was at least four-fold higher than soluble BMP-2 and less sulfated heparin MP groups, as determined by an established C2C12 cell alkaline phosphatase (ALP) assay. Ultimately, the two most sulfated 10 wt% heparin MP formulations were able to efficiently load and release BMP-2 while enhancing BMP-2 bioactivity, making them promising candidates for future growth factor delivery applications.

  4. [New materia medica project: synthetic biology based bioactive metabolites research in medicinal plant].

    Science.gov (United States)

    Wang, Yong

    2017-03-25

    In the last decade, synthetic biology research has been gradually transited from monocellular parts or devices toward more complex multicellular systems. The emerging plant synthetic biology is regarded as the "next chapter" of synthetic biology. The complex and diverse plant metabolism as the entry point, plant synthetic biology research not only helps us understand how real life is working, but also facilitates us to learn how to design and construct more complex artificial life. Bioactive compounds innovation and large-scale production are expected to be breakthrough with the redesigned plant metabolism as well. In this review, we discuss the research progress in plant synthetic biology and propose the new materia medica project to lift the level of traditional Chinese herbal medicine research.

  5. Estimating the wound healing ability of bioactive milk proteins using an optimized cell based assay

    DEFF Research Database (Denmark)

    Nyegaard, Steffen; Andreasen, Trine; Rasmussen, Jan Trige

    Milk contains many different proteins of which the larger constituents like the caseins and major whey constituents are well characterized. We have for some time been studying the structure and function of proteins associated with the milk fat globule membrane like lactadherin, MUC1/15, xanthine...... oxidoreductase along with minor whey constituents like osteopontin, EPV20 etc. The enterocyte migration rate is a key parameter in maintaining intestinal homeostasis and intestinal repair when recovering from infection or intestinal diseases like Crohns and ulcerative colitis. We developed a novel in vitro wound...... healing assay to determine the bioactive effects of various milk proteins using human small intestine cells grown on extracellular matrix. Silicone inserts are placed in a 96-well plate and enterocytes seeded around it, creating a monolayer with a cell free area. In current ongoing experiments, various...

  6. Reduced graphene oxide-coated hydroxyapatite composites stimulate spontaneous osteogenic differentiation of human mesenchymal stem cells

    Science.gov (United States)

    Lee, Jong Ho; Shin, Yong Cheol; Jin, Oh Seong; Kang, Seok Hee; Hwang, Yu-Shik; Park, Jong-Chul; Hong, Suck Won; Han, Dong-Wook

    2015-07-01

    Human mesenchymal stem cells (hMSCs) have great potential as cell sources for bone tissue engineering and regeneration, but the control and induction of their specific differentiation into bone cells remain challenging. Graphene-based nanomaterials are considered attractive candidates for biomedical applications such as scaffolds in tissue engineering, substrates for SC differentiation and components of implantable devices, due to their biocompatible and bioactive properties. Despite the potential biomedical applications of graphene and its derivatives, only limited information is available regarding their osteogenic activity. This study concentrates upon the effects of reduced graphene oxide (rGO)-coated hydroxyapatite (HAp) composites on osteogenic differentiation of hMSCs. The average particle sizes of HAp and rGO were 1270 +/- 476 nm and 438 +/- 180 nm, respectively. When coated on HAp particulates, rGO synergistically enhanced spontaneous osteogenic differentiation of hMSCs, without hampering their proliferation. This result was confirmed by determining alkaline phosphatase activity and mineralization of calcium and phosphate as early and late stage markers of osteogenic differentiation. It is suggested that rGO-coated HAp composites can be effectively utilized as dental and orthopedic bone fillers since these graphene-based particulate materials have potent effects on stimulating the spontaneous differentiation of MSCs and show superior bioactivity and osteoinductive potential.Human mesenchymal stem cells (hMSCs) have great potential as cell sources for bone tissue engineering and regeneration, but the control and induction of their specific differentiation into bone cells remain challenging. Graphene-based nanomaterials are considered attractive candidates for biomedical applications such as scaffolds in tissue engineering, substrates for SC differentiation and components of implantable devices, due to their biocompatible and bioactive properties. Despite

  7. The choice of process parameters to obtain a stable dispersion system of plant-based bioactivated dicotyledonous seeds

    Directory of Open Access Journals (Sweden)

    L. A. Samofalova

    2016-01-01

    Full Text Available The article dealswith the search for the unification of technological approaches to increase the efficiency of separation of the protein complex and stability of the plant foundations from seed dicotyledonous economically important crops of soybean, hemp, buckwheat. Uneven localization of nitrogenous substances in the seed largely determines the accessibility of protein complexes for extraction. Natural fermentation of spare proteins in cellular structures when the germination process starts leads to the accumulation of soluble nitrogen, and the change in the salt composition of protoplasm facilitates the transition in the solution of insoluble complexes in the form of colloids. It is shown that fine grinding of dry seeds increases the efficiency of extraction by 1.3–1.6 times, while rough grinding increases bioactivity by 1.6–1.8 times. The dispersion containing 8.1±0.7% of dry matter at buckwheat bases and 9.5±1,3% at hemp and soy bases with the water ratio 1:4 to 1:7 satisfy the requirements of taste sensations and fullness of the chemical composition. Based on the results of the extraction of protein of buckwheat seeds the conclusion has been drawn that there is a need for a differentiated approach to selecting conditions for the creation of food framework. Taking into consideration the fact that the amount of calcium in buckwheat seeds is17–25 times smaller than in oil seeds and the quantity of phosphorus is 1.6–2 times smaller, the contribution of electrostatic forces in the protein solubility is small and the additional actions to activate the protein complex are required. To predict the properties of vegetable bases of bioactivated soybean seeds and hemp, the central composite uniform-rotatable planning was applied and the full factorial experiment with factorial scheme 3×3×3 (33 was selected. The preferred combination of values of the input parameters X1, X2, X3 was discovered. They provide for the maximum of Y

  8. Role of magnesium oxide and strontium oxide as modifiers in silicate-based bioactive glasses: Effects on thermal behaviour, mechanical properties and in-vitro bioactivity

    International Nuclear Information System (INIS)

    Bellucci, Devis; Sola, Antonella; Salvatori, Roberta; Anesi, Alexandre; Chiarini, Luigi; Cannillo, Valeria

    2017-01-01

    The composition of a CaO-rich silicate bioglass (BG-Ca-Mix, in mol%: 2.3 Na 2 O; 2.3 K 2 O; 45.6 CaO; 2.6 P 2 O 5 ; 47.2 SiO 2 ) was modified by replacing a fixed 10 mol% of CaO with MgO or SrO or fifty-fifty MgO-SrO. The thermal behaviour of the modified glasses was accurately evaluated via differential thermal analysis (DTA), heating microscopy and direct sintering tests. The presence of MgO and/or SrO didn't interfere with the thermal stability of the parent glass, since all the new glasses remained completely amorphous after sintering (treatment performed at 753 °C for the glass with MgO; at 750 °C with SrO; at 759 °C with MgO and SrO). The sintered samples achieved good mechanical properties, with a Young's modulus ranging between 57.9 ± 6.7 for the MgO-SrO modified composition and 112.6 ± 8.0 GPa for the MgO-modified one. If immersed in a simulated body fluid (SBF), the modified glasses after sintering retained the strong apatite forming ability of the parent glass, in spite of the presence of MgO and/or SrO. Moreover, the sintered glasses, tested with MLO-Y4 osteocytes by means of a multi-parametrical approach, showed a good bioactivity in vitro, since neither the glasses nor their extracts caused any negative effect on cell viability or any inhibition on cell growth. The best results were achieved by the MgO-modified glasses, both BGMIX-Mg and BGMIX-MgSr, which were able to exert a strong stimulating effect on the cell growth, thus confirming the beneficial effect of MgO on the glass bioactivity. - Highlights: • The composition of a CaO-rich, K 2 O-containing silicate bioglass was modified: • A fixed 10 mol% of CaO was replaced with MgO or SrO or fifty-fifty MgO-SrO. • The sintered glasses showed a strong volume shrinkage with low residual porosity. • The samples showed good mechanical performance and apatite-forming ability in vitro. • The presence of such oxides, especially MgO, improves the samples' bioactivity.

  9. Role of magnesium oxide and strontium oxide as modifiers in silicate-based bioactive glasses: Effects on thermal behaviour, mechanical properties and in-vitro bioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, Devis, E-mail: devis.bellucci@unimore.it [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena (Italy); Sola, Antonella [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena (Italy); Salvatori, Roberta; Anesi, Alexandre; Chiarini, Luigi [Lab. Biomaterials, Department of Medical and Surgical Sciences of Children & Adults, University of Modena and Reggio Emilia, Via Campi 213/A, 41125 Modena (Italy); Cannillo, Valeria [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena (Italy)

    2017-03-01

    The composition of a CaO-rich silicate bioglass (BG-Ca-Mix, in mol%: 2.3 Na{sub 2}O; 2.3 K{sub 2}O; 45.6 CaO; 2.6 P{sub 2}O{sub 5}; 47.2 SiO{sub 2}) was modified by replacing a fixed 10 mol% of CaO with MgO or SrO or fifty-fifty MgO-SrO. The thermal behaviour of the modified glasses was accurately evaluated via differential thermal analysis (DTA), heating microscopy and direct sintering tests. The presence of MgO and/or SrO didn't interfere with the thermal stability of the parent glass, since all the new glasses remained completely amorphous after sintering (treatment performed at 753 °C for the glass with MgO; at 750 °C with SrO; at 759 °C with MgO and SrO). The sintered samples achieved good mechanical properties, with a Young's modulus ranging between 57.9 ± 6.7 for the MgO-SrO modified composition and 112.6 ± 8.0 GPa for the MgO-modified one. If immersed in a simulated body fluid (SBF), the modified glasses after sintering retained the strong apatite forming ability of the parent glass, in spite of the presence of MgO and/or SrO. Moreover, the sintered glasses, tested with MLO-Y4 osteocytes by means of a multi-parametrical approach, showed a good bioactivity in vitro, since neither the glasses nor their extracts caused any negative effect on cell viability or any inhibition on cell growth. The best results were achieved by the MgO-modified glasses, both BGMIX-Mg and BGMIX-MgSr, which were able to exert a strong stimulating effect on the cell growth, thus confirming the beneficial effect of MgO on the glass bioactivity. - Highlights: • The composition of a CaO-rich, K{sub 2}O-containing silicate bioglass was modified: • A fixed 10 mol% of CaO was replaced with MgO or SrO or fifty-fifty MgO-SrO. • The sintered glasses showed a strong volume shrinkage with low residual porosity. • The samples showed good mechanical performance and apatite-forming ability in vitro. • The presence of such oxides, especially MgO, improves the samples

  10. EFFECTS OF INCORPORATING NATURAL MINERALS ON PRODUCTION AND BIOACTIVITY OF BIOACTIVE GLASS CERAMICS

    Directory of Open Access Journals (Sweden)

    Franco Matias Stabile

    2016-07-01

    Full Text Available Two glass-ceramics composition were produced from natural minerals. Quartzes and feldspars were pre-selected on the basis of their purities studied by X-ray diffraction (XRD and chemical analysis. Prepared compositions of glasses precursors were two different theoretical leucite (KAlSi₂O₆ /Bioglass 45S5 (L/Bg ratios. Transformations of raw materials mixtures and glass precursors were studied by differential thermal analyses. On the basis of thermal analysis results, glass ceramics were produced and characterized by XRD. Glass-ceramics were composed of two major crystalline phases, leucite and sodium calcium silicate. Bioactivity tests were performed submerging the glass-ceramics into simulated body fluid (SBF for different periods (1, 5 and 10 days. Bioactive behavior was monitored by XRD and scanning electron microscopy (SEM. Studied samples were found to be bioactive, in which hydroxyapatite layer was developed within 5 days of contact with SBF.

  11. Hydroxyapatite formation on titania-based materials in a solution mimicking body fluid: Effects of manganese and iron addition in anatase.

    Science.gov (United States)

    Shin, Euisup; Kim, Ill Yong; Cho, Sung Baek; Ohtsuki, Chikara

    2015-03-01

    Hydroxyapatite formation on the surfaces of implanted materials plays an important role in osteoconduction of bone substitutes in bone tissues. Titania hydrogels are known to instigate hydroxyapatite formation in a solution mimicking human blood plasma. To date, the relationship between the surface characteristics of titania and hydroxyapatite formation on its surface remains unclear. In this study, titania powders with varying surface characteristics were prepared by addition of manganese or iron to examine hydroxyapatite formation in a type of simulated body fluid (Kokubo solution). Hydroxyapatite formation was monitored by observation of deposited particles with scale-like morphology on the prepared titania powders. The effect of the titania surface characteristics, i.e., crystal structure, zeta potential, hydroxy group content, and specific surface area, on hydroxyapatite formation was examined. Hydroxyapatite formation was observed on the surface of titania powders that were primarily anatase, and featured a negative zeta potential and low specific surface areas irrespective of the hydroxy group content. High specific surface areas inhibited the formation of hydroxyapatite because calcium and phosphate ions were mostly consumed by adsorption on the titania surface. Thus, these surface characteristics of titania determine its osteoconductivity following exposure to body fluid. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Hydroxyapatite-silver nanoparticles coatings on porous polyurethane scaffold

    International Nuclear Information System (INIS)

    Ciobanu, Gabriela; Ilisei, Simona; Luca, Constantin

    2014-01-01

    The present paper is focused on a study regarding the possibility of obtaining hydroxyapatite-silver nanoparticle coatings on porous polyurethane scaffold. The method applied is based on a combined strategy involving hydroxyapatite biomimetic deposition on polyurethane surface using a Supersaturated Calcification Solution (SCS), combined with silver ions reduction and in-situ crystallization processes on hydroxyapatite-polyurethane surface by sample immersing in AgNO 3 solution. The morphology, composition and phase structure of the prepared samples were characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. The data obtained show that a layer of hydroxyapatite was deposited on porous polyurethane support and the silver nanoparticles (average size 34.71 nm) were dispersed among and even on the hydroxyapatite crystals. Hydroxyapatite/polyurethane surface acts as a reducer and a stabilizing agent for silver ions. The surface plasmon resonance peak in UV-Vis absorption spectra showed an absorption maximum at 415 nm, indicating formation of silver nanoparticles. The hydroxyapatite-silver polyurethane scaffolds were tested against Staphylococcus aureus and Escherichia coli and the obtained data were indicative of good antibacterial properties of the materials. - Highlights: • The hydroxyapatite and silver nanoparticles were grown on the polyurethane scaffold • The hydroxyapatite/polyurethane acts as reducing agent, stabilizer and matrix for Ag • The samples were well characterized by SEM-EDX, XRD, XPS, UV-visible spectroscopy • The hydroxyapatite/silver polyurethane scaffold shows antibacterial property

  13. Polymer-Ceramic Composite Scaffolds: The Effect of Hydroxyapatite and β-tri-Calcium Phosphate

    Directory of Open Access Journals (Sweden)

    Boyang Huang

    2018-01-01

    Full Text Available The design of bioactive scaffolds with improved mechanical and biological properties is an important topic of research. This paper investigates the use of polymer-ceramic composite scaffolds for bone tissue engineering. Different ceramic materials (hydroxyapatite (HA and β-tri-calcium phosphate (TCP were mixed with poly-ε-caprolactone (PCL. Scaffolds with different material compositions were produced using an extrusion-based additive manufacturing system. The produced scaffolds were physically and chemically assessed, considering mechanical, wettability, scanning electron microscopy and thermal gravimetric tests. Cell viability, attachment and proliferation tests were performed using human adipose derived stem cells (hADSCs. Results show that scaffolds containing HA present better biological properties and TCP scaffolds present improved mechanical properties. It was also possible to observe that the addition of ceramic particles had no effect on the wettability of the scaffolds.

  14. Polymer-Ceramic Composite Scaffolds: The Effect of Hydroxyapatite and β-tri-Calcium Phosphate.

    Science.gov (United States)

    Huang, Boyang; Caetano, Guilherme; Vyas, Cian; Blaker, Jonny James; Diver, Carl; Bártolo, Paulo

    2018-01-14

    The design of bioactive scaffolds with improved mechanical and biological properties is an important topic of research. This paper investigates the use of polymer-ceramic composite scaffolds for bone tissue engineering. Different ceramic materials (hydroxyapatite (HA) and β-tri-calcium phosphate (TCP)) were mixed with poly-ε-caprolactone (PCL). Scaffolds with different material compositions were produced using an extrusion-based additive manufacturing system. The produced scaffolds were physically and chemically assessed, considering mechanical, wettability, scanning electron microscopy and thermal gravimetric tests. Cell viability, attachment and proliferation tests were performed using human adipose derived stem cells (hADSCs). Results show that scaffolds containing HA present better biological properties and TCP scaffolds present improved mechanical properties. It was also possible to observe that the addition of ceramic particles had no effect on the wettability of the scaffolds.

  15. Obtaining of biodegradable polylactide films and fibers filled hydroxyapatite for medical purposes

    Energy Technology Data Exchange (ETDEWEB)

    Lytkina, D. N., E-mail: darya-lytkina@yandex.ru; Shapovalova, Y. G., E-mail: elena.shapovalova@ro.ru; Rasskazova, L. A., E-mail: ly-2207@mail.ru; Kurzina, I. A., E-mail: kurzina99@mail.ru; Filimoshkin, A. G., E-mail: filag05@rambler.ru [National Research Tomsk State University 36, Lenina Avenue, Tomsk, 634050 (Russian Federation)

    2015-11-17

    Relevance of the work is due to the need for new materials that are used in medicine (orthopedics, surgery, dentistry, and others) as a substitute for natural bone tissue injuries, fractures, etc. The aim of presented work is developing of a method of producing biocompatible materials based on polyesters of hydroxycarboxylic acids and calcium phosphate ceramic (hydroxyapatite, HA) with homogeneous distribution of the inorganic component. Bioactive composites based on poly-L-lactide (PL) and hydroxyapatite with homogeneous distribution were prepared. The results of scanning electron microscopy confirm homogeneous distribution of the inorganic filler in the polymer matrix. The positive effect of ultrasound on the homogeneity of the composites was determined. The rate of hydrolysis of composites was evaluated. The rate of hydrolysis of polylactide as an individual substance is 7 times lower than the rate of hydrolysis of the polylactide as a part of the composite. It was found that materials submarines HA composite and do not cause a negative response in the cells of the immune system, while contributing to anti-inflammatory cytokines released by cells.

  16. Evaluation of the interindividual human variation in bioactivation of methyleugenol using physiologically based kinetic modeling and Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Al-Subeihi, Ala' A.A., E-mail: subeihi@yahoo.com [Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen (Netherlands); BEN-HAYYAN-Aqaba International Laboratories, Aqaba Special Economic Zone Authority (ASEZA), P. O. Box 2565, Aqaba 77110 (Jordan); Alhusainy, Wasma; Kiwamoto, Reiko; Spenkelink, Bert [Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen (Netherlands); Bladeren, Peter J. van [Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen (Netherlands); Nestec S.A., Avenue Nestlé 55, 1800 Vevey (Switzerland); Rietjens, Ivonne M.C.M.; Punt, Ans [Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen (Netherlands)

    2015-03-01

    The present study aims at predicting the level of formation of the ultimate carcinogenic metabolite of methyleugenol, 1′-sulfooxymethyleugenol, in the human population by taking variability in key bioactivation and detoxification reactions into account using Monte Carlo simulations. Depending on the metabolic route, variation was simulated based on kinetic constants obtained from incubations with a range of individual human liver fractions or by combining kinetic constants obtained for specific isoenzymes with literature reported human variation in the activity of these enzymes. The results of the study indicate that formation of 1′-sulfooxymethyleugenol is predominantly affected by variation in i) P450 1A2-catalyzed bioactivation of methyleugenol to 1′-hydroxymethyleugenol, ii) P450 2B6-catalyzed epoxidation of methyleugenol, iii) the apparent kinetic constants for oxidation of 1′-hydroxymethyleugenol, and iv) the apparent kinetic constants for sulfation of 1′-hydroxymethyleugenol. Based on the Monte Carlo simulations a so-called chemical-specific adjustment factor (CSAF) for intraspecies variation could be derived by dividing different percentiles by the 50th percentile of the predicted population distribution for 1′-sulfooxymethyleugenol formation. The obtained CSAF value at the 90th percentile was 3.2, indicating that the default uncertainty factor of 3.16 for human variability in kinetics may adequately cover the variation within 90% of the population. Covering 99% of the population requires a larger uncertainty factor of 6.4. In conclusion, the results showed that adequate predictions on interindividual human variation can be made with Monte Carlo-based PBK modeling. For methyleugenol this variation was observed to be in line with the default variation generally assumed in risk assessment. - Highlights: • Interindividual human differences in methyleugenol bioactivation were simulated. • This was done using in vitro incubations, PBK modeling

  17. Evaluation of the interindividual human variation in bioactivation of methyleugenol using physiologically based kinetic modeling and Monte Carlo simulations

    International Nuclear Information System (INIS)

    Al-Subeihi, Ala' A.A.; Alhusainy, Wasma; Kiwamoto, Reiko; Spenkelink, Bert; Bladeren, Peter J. van; Rietjens, Ivonne M.C.M.; Punt, Ans

    2015-01-01

    The present study aims at predicting the level of formation of the ultimate carcinogenic metabolite of methyleugenol, 1′-sulfooxymethyleugenol, in the human population by taking variability in key bioactivation and detoxification reactions into account using Monte Carlo simulations. Depending on the metabolic route, variation was simulated based on kinetic constants obtained from incubations with a range of individual human liver fractions or by combining kinetic constants obtained for specific isoenzymes with literature reported human variation in the activity of these enzymes. The results of the study indicate that formation of 1′-sulfooxymethyleugenol is predominantly affected by variation in i) P450 1A2-catalyzed bioactivation of methyleugenol to 1′-hydroxymethyleugenol, ii) P450 2B6-catalyzed epoxidation of methyleugenol, iii) the apparent kinetic constants for oxidation of 1′-hydroxymethyleugenol, and iv) the apparent kinetic constants for sulfation of 1′-hydroxymethyleugenol. Based on the Monte Carlo simulations a so-called chemical-specific adjustment factor (CSAF) for intraspecies variation could be derived by dividing different percentiles by the 50th percentile of the predicted population distribution for 1′-sulfooxymethyleugenol formation. The obtained CSAF value at the 90th percentile was 3.2, indicating that the default uncertainty factor of 3.16 for human variability in kinetics may adequately cover the variation within 90% of the population. Covering 99% of the population requires a larger uncertainty factor of 6.4. In conclusion, the results showed that adequate predictions on interindividual human variation can be made with Monte Carlo-based PBK modeling. For methyleugenol this variation was observed to be in line with the default variation generally assumed in risk assessment. - Highlights: • Interindividual human differences in methyleugenol bioactivation were simulated. • This was done using in vitro incubations, PBK modeling

  18. Bioactive conformational generation of small molecules: A comparative analysis between force-field and multiple empirical criteria based methods

    Directory of Open Access Journals (Sweden)

    Jiang Hualiang

    2010-11-01

    Full Text Available Abstract Background Conformational sampling for small molecules plays an essential role in drug discovery research pipeline. Based on multi-objective evolution algorithm (MOEA, we have developed a conformational generation method called Cyndi in the previous study. In this work, in addition to Tripos force field in the previous version, Cyndi was updated by incorporation of MMFF94 force field to assess the conformational energy more rationally. With two force fields against a larger dataset of 742 bioactive conformations of small ligands extracted from PDB, a comparative analysis was performed between pure force field based method (FFBM and multiple empirical criteria based method (MECBM hybrided with different force fields. Results Our analysis reveals that incorporating multiple empirical rules can significantly improve the accuracy of conformational generation. MECBM, which takes both empirical and force field criteria as the objective functions, can reproduce about 54% (within 1Å RMSD of the bioactive conformations in the 742-molecule testset, much higher than that of pure force field method (FFBM, about 37%. On the other hand, MECBM achieved a more complete and efficient sampling of the conformational space because the average size of unique conformations ensemble per molecule is about 6 times larger than that of FFBM, while the time scale for conformational generation is nearly the same as FFBM. Furthermore, as a complementary comparison study between the methods with and without empirical biases, we also tested the performance of the three conformational generation methods in MacroModel in combination with different force fields. Compared with the methods in MacroModel, MECBM is more competitive in retrieving the bioactive conformations in light of accuracy but has much lower computational cost. Conclusions By incorporating different energy terms with several empirical criteria, the MECBM method can produce more reasonable conformational

  19. SpirPep: an in silico digestion-based platform to assist bioactive peptides discovery from a genome-wide database.

    Science.gov (United States)

    Anekthanakul, Krittima; Hongsthong, Apiradee; Senachak, Jittisak; Ruengjitchatchawalya, Marasri

    2018-04-20

    web and database server are available at http://spirpepapp.sbi.kmutt.ac.th . SpirPep, a web-based bioactive peptide discovery application, is an in silico-based tool with an overview of the results. The platform is a one-stop analysis and visualization facility; and offers advantages over the currently available tools. This tool may be useful for further bioactivity analysis and the quantitative discovery of desirable peptides.

  20. Hydroxyapatite synthesis using EDTA

    Science.gov (United States)

    Kang, Nak Heon; Kim, Soon Je; Song, Seung Han; Choi, Sang mun; Choi, Sik Young; Kim, Youn Jung

    2013-01-01

    Bone comprises structure of body and is consisted of inorganic substances. It exists in an organic structure in the body. Even though it is firm and has self healing mechanism, it can be damaged by trauma, cancer, or bone diseases. Allograft can be an alternative solution for autologous bone graft. Hydroxyapatite(Ca10(PO4)6(OH)2), an excellent candidate for allograft, can be applied to bone defect area. There are several methods to produce hydroxyapatite, however economical cost and time consuming make the production difficult. In this study we synthesized the hydroxyapatite with Ethyenediamine tetraacetic acid. Freeze Dried Bone Allograft(Hans Biomed) was used to be a control group. Synthesized hydroxyapatite was a rod shape, white powdery type substance with 2 ~ 5 μm length and 0.5 ~ 1 μm width. X-ray diffraction showed the highest sharp peak at 32° and high peaks at 25.8°, 39.8°, 46.8°, 49.5°, and 64.0° indicating a similar substance to the freeze Dried Bone Allograft. 3 days after the cell growth of synthesized hydroxyapatite showed 1.5 fold more than the Bone Allograft. Cellular and media alkaline phosphate activity increased similar to the bone alloagraft. In this study we came up with a new method to produce the hydroxyapatite. It is a convenient method that can be held in room temperature and low pressure. Also the the product can be manufactured in large quantity. It can be also transformed into scaffold structure which will perform a stronger configuration. The manufacturing method will help the bony defect patients and make future medical products. PMID:23714942

  1. Hydroxyapatite synthesis using EDTA.

    Science.gov (United States)

    Kang, Nak Heon; Kim, Soon Je; Song, Seung Han; Choi, Sang mun; Choi, Sik Young; Kim, Youn Jung

    2013-05-01

    Bone comprises structure of the body and consisted of inorganic substances. It exists in an organic structure in the body. Even though it is firm and has self-healing mechanism, it can be damaged by trauma, cancer, or bone diseases. Allograft can be an alternative solution for autologous bone graft. Hydroxyapatite (Ca10(PO4)6(OH)2), an excellent candidate for allograft, can be applied to bone defect area. There are several methods to produce hydroxyapatite; however, economical cost and being time consuming make the production difficult. In this study, we synthesized hydroxyapatite with EDTA. Freeze-dried bone allograft (Hans Biomed) was used as the control group. Synthesized hydroxyapatite was a rod-shaped, white powdery substance with 2- to 5-μm length and 0.5- to 1-μm width. X-ray diffraction showed the highest sharp peak at 32°C and high peaks at 25.8°C, 39.8°C, 46.8°C, 49.5°C, and 64.0°C, indicating a similar substance to the freeze-dried bone allograft. After 3 days, the cell growth of synthesized hydroxyapatite showed 1.5-fold more than did the bone allograft. Cellular and media alkaline phosphate activity increased similar to the bone allograft. In this study, we came up with a new method to produce the hydroxyapatite. It is a convenient method that can be held in room temperature and low pressure. Also, the product can be manufactured in large quantity. It can be also transformed into scaffold structure, which will perform a stronger configuration. The manufacturing method will help the bony defect patients and make future medical products.

  2. Thermal analysis and in vitro bioactivity of bioactive glass-alumina composites

    Energy Technology Data Exchange (ETDEWEB)

    Chatzistavrou, Xanthippi, E-mail: x.chatzistavrou@imperial.ac.uk [Solid State Physics Section, Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kantiranis, Nikolaos, E-mail: kantira@geo.auth.gr [School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kontonasaki, Eleana, E-mail: kont@dent.auth.gr [School of Dentistry, Department of Fixed Prosthesis and Implant Prosthodontics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chrissafis, Konstantinos, E-mail: hrisafis@physics.auth.gr [Solid State Physics Section, Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Papadopoulou, Labrini, E-mail: lambrini@geo.auth.gr [School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Koidis, Petros, E-mail: pkoidis@dent.auth.gr [School of Dentistry, Department of Fixed Prosthesis and Implant Prosthodontics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Boccaccini, Aldo R., E-mail: a.boccaccini@imperial.ac.uk [Department of Materials, Faculty of Engineering, Imperial College, SW7 2AZ London (United Kingdom); Paraskevopoulos, Konstantinos M., E-mail: kpar@auth.gr [Solid State Physics Section, Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2011-01-15

    Bioactive glass-alumina composite (BA) pellets were fabricated in the range 95/5-60/40 wt.% respectively and were heat-treated under a specific thermal treatment up to 950 {sup o}C. Control (unheated) and heat-treated pellets were immersed in Simulated Body Fluid (SBF) for bioactivity testing. All pellets before and after immersion in SBF were studied by Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM-EDS) and X-ray Diffraction (XRD) analysis. All composite pellets presented bioactive response. On the surface of the heat-treated pellets the development of a rich biological hydroxyapatite (HAp) layer was delayed for one day, compared to the respective control pellets. Independent of the proportion of the two components, all composites of each group (control and heat-treated) presented the same bioactive response as a function of immersion time in SBF. It was found that by the applied methodology, Al{sub 2}O{sub 3} can be successfully applied in bioactive glass composites without obstructing their bioactive response. - Research Highlights: {yields} Isostatically pressed glass-alumina composites presented apatite-forming ability. {yields} The interaction with SBF resulted in an aluminium phosphate phase formation. {yields} The formation of an aluminium phosphate phase enhanced the in vitro apatite growth.

  3. Preparation and characterization of an iron oxide-hydroxyapatite nanocomposite for potential bone cancer therapy.

    Science.gov (United States)

    Sneha, Murugesan; Sundaram, Nachiappan Meenakshi

    2015-01-01

    Recently, multifunctional magnetic nanostructures have been found to have potential applications in biomedical and tissue engineering. Iron oxide nanoparticles are biocompatible and have distinctive magnetic properties that allow their use in vivo for drug delivery and hyperthermia, and as T2 contrast agents for magnetic resonance imaging. Hydroxyapatite is used frequently due to its well-known biocompatibility, bioactivity, and lack of toxicity, so a combination of iron oxide and hydroxyapatite materials could be useful because hydroxyapatite has better bone-bonding ability. In this study, we prepared nanocomposites of iron oxide and hydroxyapatite and analyzed their physicochemical properties. The results suggest that these composites have superparamagnetic as well as biocompatible properties. This type of material architecture would be well suited for bone cancer therapy and other biomedical applications.

  4. Sorption of technetium on composite chitosan-hydroxyapatite from aqueous solutions

    International Nuclear Information System (INIS)

    Pivarciova, L.; Rosskopfova, O.; Galambos, M.; Rajec, P.

    2013-01-01

    Biomaterials such as natural polymers (chitosan) and hydroxyapatite have an important application in material for bone replacement. Most of chitosan/hydroxyapatite composites are prepared by mixing hydroxyapatite particles with chitosan matrices. Another method of preparation of chitosan/hydroxyapatite composite is in-situ generation of nano-hydroxyapatite in chitosan matrix. The most common biomaterial used in the past years in hard tissue regeneration was hydroxyapatite, owing to its properties as biocompatibility, bioactivity, non-toxicity, non-immunogenicity etc. Chitosan is a polyaminosacharide, partially deacetylated product of chitin. Chitosan can be used in combination with other materials to enhance bone growth such as bone filling paste. The aims of this work were: the influence of the contact time on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of pH on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of foreign ions on sorption of pertechnate anions on chitosan/hydroxyapatite composites. The author concluded: the percentage of technetium sorption after 1 hour of contact time was > 97 %. In the initial pH range of 2.9-10.2, the percentage of technetium sorption on chitosan/hydroxyapatite composites CH/HA(A), CH/HA(B), CH/HA 30:70, ZCH was > 98 % and on CH/HA 50:50 was > 94%. The competition effect of Fe 2+ towards TcO 4 :- sorption is stronger than competition effect of other observed cations for all examined composites with the same weight ratio. The percentage of the technetium sorption was the same for all composites with the weight ratio of 30:70. (authors)

  5. Surface Modification of Porous Titanium Granules for Improving Bioactivity.

    Science.gov (United States)

    Karaji, Zahra Gorgin; Houshmand, Behzad; Faghihi, Shahab

    The highly porous titanium granules are currently being used as bone substitute material and for bone tissue augmentation. However, they suffer from weak bone bonding ability. The aim of this study was to create a nanostructured surface oxide layer on irregularly shaped titanium granules to improve their bioactivity. This could be achieved using optimized electrochemical anodic oxidation (anodizing) and heat treatment processes. The anodizing process was done in an ethylene glycol-based electrolyte at an optimized condition of 60 V for 3 hours. The anodized granules were subsequently annealed at 450°C for 1 hour. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) were used to characterize the surface structure and morphology of the granules. The in vitro bioactivity of the samples was evaluated by immersion of specimens in simulated body fluid (SBF) for 1, 2, and 3 weeks. The human osteoblastic sarcoma cell line, MG63, was used to evaluate cell viability on the samples using dimethylthiazol-diphenyl tetrazolium bromide (MTT) assay. The results demonstrated the formation of amorphous nanostructured titanium oxide after anodizing, which transformed to crystalline anatase and rutile phases upon heat treatment. After immersion in SBF, spherical aggregates of amorphous calcium phosphate were formed on the surface of the anodized sample, which turned into crystalline hydroxyapatite on the surface of the anodized annealed sample. No cytotoxicity was detected among the samples. It is suggested that anodic oxidation followed by heat treatment could be used as an effective surface treatment procedure to improve bioactivity of titanium granules implemented for bone tissue repair and augmentation.

  6. Synthesis and characterization of composite based on cellulose acetate and hydroxyapatite application to the absorption of harmful substances.

    Science.gov (United States)

    Azzaoui, Khalil; Lamhamdi, Abdelatif; Mejdoubi, El Miloud; Berrabah, Mohammed; Hammouti, Belkheir; Elidrissi, Abderrahman; Fouda, Moustafa M G; Al-Deyab, Salem S

    2014-10-13

    The aim of this work is to develop composite materials with hydroxyapatite (HAp) mineral and organic matrix such as cellulosic polymers. We use cellulose acetate with different percentages, and then inorganic-organic films were fabricated by evaporation of solvent. The composite films were characterized using emission scanning electron microscopy (FEG-SEM), thermo-gravimetric analysis (TGA) and Fourier transform infra-red (FT-IR) spectra. Test results show that these films are uniform and have good ductility. A strong interaction existed between HAp and cellulosic polymers, and the method allows the production of very fine particles size of about 92 nm. We have developed a new chromatographic method for the quantification of bisphenol A (BPA) in samples of baby food. The result of this study demonstrates how to use this type of composite materials to remove pollutants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Introducing an attractive method for total biomimetic creation of a synthetic biodegradable bioactive bone scaffold based on statistical experimental design.

    Science.gov (United States)

    Shahbazi, Sara; Zamanian, Ali; Pazouki, Mohammad; Jafari, Yaser

    2018-05-01

    A new total biomimetic technique based on both the water uptake and degradation processes is introduced in this study to provide an interesting procedure to fabricate a bioactive and biodegradable synthetic scaffold, which has a good mechanical and structural properties. The optimization of effective parameters to scaffold fabrication was done by response surface methodology/central composite design (CCD). With this method, a synthetic scaffold was fabricated which has a uniform and open-interconnected porous structure with the largest pore size of 100-200μm. The obtained compressive ultimate strength of ~35MPa and compression modulus of 58MPa are similar to some of the trabecular bone. The pore morphology, size, and distribution of the scaffold were characterized using a scanning electron microscope and mercury porosimeter. Fourier transform infrared spectroscopy, EDAX and X-ray diffraction analyses were used to determine the chemical composition, Ca/P element ratio of mineralized microparticles, and the crystal structure of the scaffolds, respectively. The optimum biodegradable synthetic scaffold based on its raw materials of polypropylene fumarate, hydroxyethyl methacrylate and nano bioactive glass (PPF/HEMA/nanoBG) as 70/30wt/wt%, 20wt%, and 1.5wt/wt% (PHB.732/1.5) with desired porosity, pore size, and geometry were created by 4weeks immersion in SBF. This scaffold showed considerable biocompatibility in the ranging from 86 to 101% for the indirect and direct contact tests and good osteoblast cell attachment when studied with the bone-like cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. The Immunomodulatory Potential of Selected Bioactive Plant-Based Compounds in Breast Cancer: A Review.

    Science.gov (United States)

    Baraya, Yushau Shuaibu; Wong, Kah Keng; Yaacob, Nik Soriani

    2017-01-01

    Breast cancer has continued to cause high cancer death rates among women worldwide. The use of plants' natural products in breast cancer treatment has received more attention in recent years due to their potentially wider safety margin and the potential to complement conventional chemotherapeutic drugs. Plantbased products have demonstrated anticancer potential through different biological pathways including modulation of the immune system. Immunomodulatory properties of medicinal plants have been shown to mitigate breast cancer cell growth. Different immune cell types participate in this process especially cytotoxic T cells and natural killer cells, and cytokines including chemokines and tumor necrosis factor-α. Medicinal plants such as Glycyrrhiza glabra, Uncaria tomentosa, Camellia sinensis, Panax ginseng, Prunus armenaica (apricot), Allium sativum, Arctium lappa and Curcuma longa were reported to hold strong potential in breast cancer treatment in various parts of the world. Interestingly, research findings have shown that these plants possess bioactive immunomodulators as their main constituents producing the anticancer effects. These immunomodulatory compounds include ajoene, arctigenin, β-carotene, curcumin, epigallocatechin-3-gallate, ginsan, glabridin and quinic acid. In this review, we discussed the ability of these eight immunomodulators in regulating the immune system potentially applicable in breast cancer treatment via anti-inflammatory (curcumin, arctigenin, glabridin and ajoene) and lymphocytes activation (β-carotene, epigallocatechin-3-gallate, quinic acid and ginsan) properties, as well as future research direction in their use for breast cancer treatment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Food-grade protein-based nanoparticles and microparticles for bioactive delivery: fabrication, characterization, and utilization.

    Science.gov (United States)

    Davidov-Pardo, Gabriel; Joye, Iris J; McClements, David Julian

    2015-01-01

    Proteins can be used to fabricate nanoparticles and microparticles suitable for use as delivery systems for bioactive compounds in pharmaceutical, food, cosmetic, and other products. Food proteins originate from various animal or vegetal sources and exhibit a wide diversity of molecular and physicochemical characteristics, e.g., molecular weight, conformation, flexibility, polarity, charge, isoelectric point, solubility, and interactions. As a result, protein particles can be assembled using numerous different preparation methods, from one or more types of protein or from a combination of a protein and another type of biopolymer (usually a polysaccharide). The final characteristics of the particles produced are determined by the proteins and/or polysaccharides used, as well as the fabrication techniques employed. This chapter provides an overview of the functional properties of food proteins that can be used to assemble nanoparticles and microparticles, the fabrication techniques available to create those particles, the factors that influence their stability, and their potential applications within the food industry. © 2015 Elsevier Inc. All rights reserved.

  10. β-Dicalcium silicate-based cement: synthesis, characterization and in vitro bioactivity and biocompatibility studies.

    Science.gov (United States)

    Correa, Daniel; Almirall, Amisel; García-Carrodeguas, Raúl; dos Santos, Luis Alberto; De Aza, Antonio H; Parra, Juan; Delgado, José Ángel

    2014-10-01

    β-dicalcium silicate (β-Ca₂ SiO₄, β-C₂ S) is one of the main constituents in Portland cement clinker and many refractory materials, itself is a hydraulic cement that reacts with water or aqueous solution at room/body temperature to form a hydrated phase (C-S-H), which provides mechanical strength to the end product. In the present investigation, β-C₂ S was synthesized by sol-gel process and it was used as powder to cement preparation, named CSiC. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid solutions and human osteoblast cell cultures for various time periods, respectively. The results showed that the sol-gel process is an available synthesis method in order to obtain a pure powder of β-C₂ S at relatively low temperatures without chemical stabilizers. A bone-like apatite layer covered the material surface after soaking in SBF and its compressive strength (CSiC cement) was comparable with that of the human trabecular bone. The extracts of this cement were not cytotoxic and the cell growth and relative cell viability were comparable to negative control. © 2013 Wiley Periodicals, Inc.

  11. Synthesis and characterization of Cu-doped hydroxyapatite nanorods for cancer diagnosis

    International Nuclear Information System (INIS)

    Rezende, Michele Rocha; Cipreste, Marcelo Fernandes; Aragon, Fermin Herrera; Leal, Alexandre Soares; Macedo, Waldemar Augusto de Almeida; Sousa, Edesia Martins Barros de

    2016-01-01

    Full text: Theranostic nanomaterials have been widely studied around the world for the cancer treatment strategies management due to the unique property that allows nanoparticles to spontaneously and selectively accumulate in tumor sites and make simultaneously diagnosis and treatment of many types of tumors [1]. Beyond the various classes of nanomaterials, hydroxyapatite (HA) nanorods are highlighted as important bioceramics that present biocompatibility, bioactivity and osteoinductivity. Another important feature of hydroxyapatite is that HA nanorods, as nanocrystalline structures, allow replacement of its internal ionic components for metallic elements to impart new properties to the material. A diagnostic nanomaterial can be obtained by the doping HA nanorods with cooper and promoting the neutron activation of HA-Cu in nuclear reactor, producing the HA- 64 Cu nanorods. 64 Cu is a positron emitter radionuclide that allows its usage in PET scan equipment. However, high concentrations of cooper ions are toxic to human organism [2]. Nevertheless, the production of stable HA-Cu nanorods is of great interest making possible to eliminate the cytotoxicity of cooper based radiotracers. The aim of the present work was to synthesize cooper-doped HA nanorods by co-precipitation method, characterize the samples by XRD with Rietveld refinement, SEM, FTIR and EDX. The stability of the chemical interactions between HA and Gd was investigated in aqueous suspensions at different time intervals and the suspensions were analyzed by ICP-AES. The results indicate that Cu can be allocated in HA lattice, forming a stable interaction where no cooper ions can be released from the hydroxyapatite matrix, crediting this material for neutron activation assays and future biological tests. References: [1] E. Lim et al. Chem. Rev. 115:327 (2015); [2] G. Malandrinos et al. Coord. Chem. Rev. 262:55 (2014). (author)

  12. Characterization of hydroxyapatite coatings deposited by hydrothermal electrochemical method on NaOH immersed Ti6Al4V

    International Nuclear Information System (INIS)

    He, Daihua; Liu, Ping; Liu, Xinkuan; Ma, Fengcang; Chen, Xiaohong; Li, Wei; Du, Jiandi; Wang, Pu; Zhao, Jun

    2016-01-01

    The hydrothermal electrochemical method was used to deposit hydroxyapatite coating on Ti6Al4V. In order to improve the bonding strength between the coating and substrate, the substrates were modified by 8 M NaOH solution before the deposition. The effects of immersing time on the substrate, on the hydroxyapatite coating, and on the bonding strength were studied. X-Ray Diffraction, Scanning Electron Microscope, Fourier Transform Infrared Spectroscopy and Drop Shape Analysis Method were applied. And the crystallinity of hydroxyapatite coating was calculated. The results show that immersing treatment effects the phase compositions, the microstructure and the wettability of the substrate surface. A porous, three-dimensional network structure is formed on the Ti6Al4V surface through the NaOH immersion. The pore size and depth increase with the increase of immersing time from 12 to 48 h. The surface microstructure of Ti6Al4V with 60 h′ immersion time was different from the others. The modification treatment can improve the bonding strength between hydroxyapatite coating and the substrate obviously. The value of the bonding strength with the substrate immersed for 48 h is larger than those of the others. A bone-like apatite layer forms on the coating after 3 days of soaking in SBF, implying with good bioactivity of the hydroxyapatite coatings deposited by the method. The surface characteristics of the sample immersed with 48 h are more conductive to the deposition of hydroxyapatite and to the improvement of the bonding strength. The formation mechanism of hydroxyapatite coating deposited by hydrothermal electrochemical method was discussed. - Highlights: • Immerse Ti6Al4V alloy with NaOH solution for different immersing time. • We deposit hydroxyapatite coating by hydrothermal electrochemical method. • We examine changes of composition, microstructure, bonding strength and bioactivity of the hydroxyapatite coating. • 48 h is the optimal immersing time. • We

  13. Macroporous synthetic hydroxyapatite bioceramics for bone substitute applications

    CSIR Research Space (South Africa)

    Thomas, ME

    1999-08-01

    Full Text Available An improved strategy is described for the manufacture of macroporous hydroxyapatite bioceramics for bone substitute applications. This is based on a modified fugitive phase technique, which allows production of relatively open, high-strength devices...

  14. Mechanical and cytotoxicity evaluation of nanostructured hydroxyapatite-bredigite scaffolds for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Eilbagi, Marjan; Emadi, Rahmatollah; Raeissi, Keyvan [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Kharaziha, Mahshid, E-mail: ma.kharaziha@gmail.com [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Valiani, Ali [Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan 81746-73441 (Iran, Islamic Republic of)

    2016-11-01

    Despite the attractive characteristics of three-dimensional pure hydroxyapatite (HA) scaffolds, due to their weak mechanical properties, researches have focused on the development of composite scaffolds via introducing suitable secondary components. The aim of this study was to develop, for the first time, three-dimensional HA-bredigite (Ca{sub 7}MgSi{sub 4}O{sub 16}) scaffolds containing various amounts of bredigite nanopowder (0, 5, 10 and 15 wt.%) using space holder technique. Transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction spectroscopy were applied in order to study the morphology, fracture surface and phase compositions of nanopowders and scaffolds. Furthermore, the effects of scaffold composition on the mechanical properties, bioactivity, biodegradability, and cytotoxicity were also evaluated. Results showed that the composite scaffolds with average pore size in the range of 220–310 μm, appearance porosity of 63.1–75.9% and appearance density of 1.1 ± 0.04 g/cm{sup 3} were successfully developed, depending on bredigite content. Indeed, the micropore size of the scaffolds reduced with increasing bredigite content confirming that the sinterability of the scaffolds was improved. Furthermore, the compression strength and modulus of the scaffolds significantly enhanced via incorporation of bredigite content from 0 to 15 wt.%. The composite scaffolds revealed superior bioactivity and biodegradability with increasing bredigite content. Moreover, MTT assay confirmed that HA-15 wt.% bredigite scaffold significantly promoted cell proliferation compared to tissue culture plate (control) and HA scaffold. Based on these results, three-dimensional HA-bredigite scaffolds could be promising replacements for HA scaffolds in bone regeneration. - Highlights: • Nanostructured hydroxyapatite-bredigite composite scaffolds were developed using space holder technique. • Presence of bredigite

  15. Mechanistic investigation on microbial toxicity of nano hydroxyapatite on implant associated pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Baskar, K. [Department of Biotechnology, University of Madras, Guindy Campus, Chennai, Tamil Nadu (India); Anusuya, T. [Department of Nanotechnology, SRM University, Kattankulathur, Tamil Nadu (India); Devanand Venkatasubbu, G., E-mail: gdevanandvenkatasubbu@gmail.com [Department of Nanotechnology, SRM University, Kattankulathur, Tamil Nadu (India)

    2017-04-01

    The use of atomic scale inorganic nanoparticles (NPs) to fight against pathogenic microorganisms is a recent trend in biomedical area which overcomes the limitations of organic compounds in terms of stability, shelf life and bioactivity. One such Calcium phosphate based biomaterial is hydroxyapatite (HA), considered as potential bioactive compound with excellent biocompatibility, osteointegrity and biodegradability. Osteomyelitis, the implant associated infection, is the major problem worldwide responsible for the majority of implant failure cases. Since HA is used as a coating material of implants, only few reports were available on its antimicrobial activity and cytotoxicity whereas no reports on its possible antimicrobial mechanism. In this present study, the HA-NPs were synthesized by wet chemical precipitation and were characterized using X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The synthesized HA-NPs were evaluated for antimicrobial activity against implant associated bacterial pathogens. The study also explores the mechanistic action of HA-NPs in killing of bacteria by determining the reactive oxygen species (ROS) generation, DNA fragmentation, Lactate dehydrogenase (LDH) leakage and cellular interaction. In addition the cytotoxicity of HA-NPs was determined by MTT assay and Fluorescence Microscopic analysis. The results revealed that, the synthesized HA-NPs showed good antibacterial activity for tested bacterial species and the possible antibacterial mechanism were due to the lack of membrane integrity and cytotoxic studies shows the concentration dependent changes in cell viability. - Highlights: • Antibacterial activity against Gram − ve bacterium • Mechanism of antibacterial activity is analyzed. • DNA fragmentation, growth curve, LDH, ROS are analyzed. • The mechanism is by damaging cell membrane. • Hydroxyapatite is biocompatible.

  16. Correlation between acoustical and structural properties of glasses: Extension of Abd El-Moneim model for bioactive silica based glasses

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Moneim, Amin, E-mail: aminabdelmoneim@hotmail.com

    2016-04-15

    Correlation between room temperature ultrasonic attenuation coefficient and the most significant structural parameters has been studied in the bioactive silica based glasses, for the first time. The correlation has been carried out in the quaternary SiO{sub 2}–Na{sub 2}O–CaO–P{sub 2}O{sub 5} glass system using the two semi-empirical formulas, which have been presented recently by the author. Changes in the elastic properties, related to the substitution of SiO{sub 2} by alkali Na{sub 2}O and alkaline earth CaO oxides, have also been deduced by evaluating the mean atomic volume, packing density, fractal bond connectivity and density of the analogous crystalline structure. Furthermore, values of the theoretical elastic moduli have been calculated on the basis of Makishima-Mackenzie theory and compared with the corresponding observed values. Results show that the correlation between ultrasonic attenuation coefficient and the oxygen density, average atomic ring size, first-order stretching force constant and experimental bulk modulus was achieved at 5 MHz frequency. Values of the theoretically calculated shear modulus are in excellent correlation (C. R. ≻95%) with the corresponding experimental ones. The divergence between the theoretical and experimental values of bulk modulus has been discussed. - Highlights: • Abd El-Moneim model was extended for bioactive glasses. • Ultrasonic attenuation was correlated with structural parameters. • Correlation was carried out in Si–Na–Ca–P glasses. • The model is valid for all investigated glass samples. • Agreement between theoretical and experimental elastic moduli was studied.

  17. Electrophoretic deposition of ZnO/alginate and ZnO-bioactive glass/alginate composite coatings for antimicrobial applications

    Energy Technology Data Exchange (ETDEWEB)

    Cordero-Arias, L.; Cabanas-Polo, S.; Goudouri, O.M. [Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, D-91058 Erlangen (Germany); Misra, S.K. [Materials Science and Engineering, Indian Institute of Technology Gandhinagar, Ahmedabad 382424 (India); Gilabert, J. [Institute of Ceramics Materials (ITC), University Jaume I, Avenida Vicent SosBaynat, 12006 Castellon (Spain); Valsami-Jones, E. [School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Sanchez, E. [Institute of Ceramics Materials (ITC), University Jaume I, Avenida Vicent SosBaynat, 12006 Castellon (Spain); Virtanen, S. [Institute for Surface Science and Corrosion (LKO, WW4), Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany); Boccaccini, A.R., E-mail: aldo.boccaccini@ww.uni-erlangen.de [Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, D-91058 Erlangen (Germany)

    2015-10-01

    Two organic/inorganic composite coatings based on alginate, as organic matrix, and zinc oxide nanoparticles (n-ZnO) with and without bioactive glass (BG), as inorganic components, intended for biomedical applications, were developed by electrophoretic deposition (EPD). Different n-ZnO (1–10 g/L) and BG (1–1.5 g/L) contents were studied for a fixed alginate concentration (2 g/L). The presence of n-ZnO was confirmed to impart antibacterial properties to the coatings against gram-negative bacteria Escherichia coli, while the BG induced the formation of hydroxyapatite on coating surfaces thereby imparting bioactivity, making the coating suitable for bone replacement applications. Coating composition was analyzed by thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) analyses. Scanning electron microscopy (SEM) was employed to study both the surface and the cross section morphology of the coatings. Polarization curves of the coated substrates made in cell culture media at 37 °C confirmed the corrosion protection function of the novel organic/inorganic composite coatings. - Highlights: • Organic–inorganic nanocomposite coatings fabricated by electrophoretic deposition • nZnO and bioactive glass containing alginate coatings exhibit antibacterial effect. • Bioactive character and anticorrosion function of coatings demonstrated.

  18. Crystal imperfection studies of pure and silicon substituted hydroxyapatite using Raman and XRD.

    Science.gov (United States)

    Zou, Shuo; Huang, Jie; Best, Serena; Bonfield, William

    2005-12-01

    Hydroxyapatite (HA) is important in biomedical applications because of its chemical similarity to the mineral content of bone and its consequent bioactivity. Silicon substitution into the hydroxyapatite crystal lattice was found to enhance its bioactivity both in vitro and in vivo [1, 2]. However, the mechanism for the enhancement is still not well understood. In this paper, the crystal imperfections introduced by silicon substitution were studied using XRD and Raman spectroscopy. It was found that silicon substitution did not introduce microstrain, but deceased the crystal size in the hk0 direction. Three new vibration modes and peak broadening were observed in Raman spectra following silicon incorporation. The imperfections introduced by silicon substitution may play a role in enhancing bioactivity. A phenomenological relationship between the width of the PO4 v1 peak and crystal size was established.

  19. Novel bioactive materials developed by simulated body fluid evaluation: Surface-modified Ti metal and its alloys.

    Science.gov (United States)

    Kokubo, Tadashi; Yamaguchi, Seiji

    2016-10-15

    Until the discovery of the bone-bonding activity of Bioglass by Hench et al. in the early 1970s, it had not been demonstrated that a synthetic material could bond to living bone without eliciting a foreign body reaction. Since then, various kinds of materials based on calcium phosphate, such as sintered hydroxyapatite and β-tricalcium phosphate have also been shown to bond to living bone. Until the discovery of the bone-bonding activity of Ti metal formed with a sodium titanate surface layer by the present authors in 1996, it had not been shown that a metallic material could bond to living bone. Since then, various kinds of surface-modified Ti metal and its alloys have been found to bond to living bone. Until the discovery of the osteoinduction of porous hydroxyapatite by Yamasaki in 1990, it was unknown whether a synthetic material could induce bone formation even in muscle tissue. Since then, various kinds of porous calcium phosphate ceramics have been shown to induce osteoinduction. Until the discovery of osteoinduction induced by a porous Ti metal formed with a titanium oxide surface layer by Fujibayashi et al. in 2004, it had been unclear whether porous metals would be able to induce osteoinduction. These novel bioactive materials have been developed by systematic research into the apatite formation that occurs on surface-modified Ti metal and its related materials in an acellular simulated body fluid (SBF) having ion concentrations almost equal to those of human blood plasma. Some of the novel bioactive materials based on Ti metal are already in clinical use or clinical trials, such as artificial hip joints and spinal fusion devices. In the present paper, we review how these novel bioactive materials based on Ti metal have been developed based on an evaluation of apatite formation in SBF. Without the SBF evaluation, these novel bioactive materials would most likely never have been developed. On the basis of systematic study of apatite formation on a material

  20. Hydroxyapatite-silver nanoparticles coatings on porous polyurethane scaffold.

    Science.gov (United States)

    Ciobanu, Gabriela; Ilisei, Simona; Luca, Constantin

    2014-02-01

    The present paper is focused on a study regarding the possibility of obtaining hydroxyapatite-silver nanoparticle coatings on porous polyurethane scaffold. The method applied is based on a combined strategy involving hydroxyapatite biomimetic deposition on polyurethane surface using a Supersaturated Calcification Solution (SCS), combined with silver ions reduction and in-situ crystallization processes on hydroxyapatite-polyurethane surface by sample immersing in AgNO3 solution. The morphology, composition and phase structure of the prepared samples were characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. The data obtained show that a layer of hydroxyapatite was deposited on porous polyurethane support and the silver nanoparticles (average size 34.71 nm) were dispersed among and even on the hydroxyapatite crystals. Hydroxyapatite/polyurethane surface acts as a reducer and a stabilizing agent for silver ions. The surface plasmon resonance peak in UV-Vis absorption spectra showed an absorption maximum at 415 nm, indicating formation of silver nanoparticles. The hydroxyapatite-silver polyurethane scaffolds were tested against Staphylococcus aureus and Escherichia coli and the obtained data were indicative of good antibacterial properties of the materials. © 2013.

  1. Sterilisation effect study on granular hydroxyapatite (HA)

    International Nuclear Information System (INIS)

    Saidu, M.F.; Mashita, M.; Khadijah, K.; Fazan, F.; Khalid, K.A.

    2004-01-01

    Hydroxyapatite (HA) is a calcium phosphate bio ceramic that has been shown by many authors to be biocompatible with bioactive properties. It is widely accepted as the best synthetic material available for surgical use as a bone graft substitute. HA granules produced by Amerce-SIRIM from local materials underwent 5 types of sterilisation techniques with different ageing periods. Samples were tested for chemical and phase composition and microbial contamination before and after being sterilised. From the microbiological tests done, none of the unsterilised positive control yielded a positive culture. Results from X-Ray diffraction studies found that all the sterilisation techniques did not chemically degrade or structurally change the HA granules significantly. (Author)

  2. Bioactivity, mechanical properties and drug delivery ability of bioactive glass-ceramic scaffolds coated with a natural-derived polymer.

    Science.gov (United States)

    Araújo, M; Viveiros, R; Philippart, A; Miola, M; Doumett, S; Baldi, G; Perez, J; Boccaccini, A R; Aguiar-Ricardo, A; Verné, E

    2017-08-01

    In this work, hybrid melanin-coated bioactive glass-ceramic multifunctional scaffolds were developed and characterized in terms of mechanical strength, in vitro bioactivity in simulated body fluid (SBF) and ability to load ibuprofen. The coated scaffolds exhibited an accelerated bioactivity in comparison with the uncoated ones, being able of developing hydroxyapatite-like crystals after 7days soaking in simulated body fluid (SBF). Besides its positive influence on the scaffolds bioactivity, the melanin coating was able to enhance their mechanical properties, increasing the initial compressive strength by a factor of >2.5. Furthermore, ibuprofen was successfully loaded on this coating, allowing a controlled drug release of the anti-inflammatory agent. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Effect of Alumina Incorporation on the Surface Mineralization and Degradation of a Bioactive Glass (CaO-MgO-SiO2-Na2O-P2O5-CaF2-Glycerol Paste

    Directory of Open Access Journals (Sweden)

    Dilshat Tulyaganov

    2017-11-01

    Full Text Available This study investigates the dissolution behavior as well as the surface biomineralization in simulated body fluid (SBF of a paste composed of glycerol (gly and a bioactive glass in the system CaO-MgO-SiO2-Na2O-P2O5-CaF2 (BG. The synthesis of the bioactive glass in an alumina crucible has been shown to significantly affect its bioactivity due to the incorporation of aluminum (ca. 1.3–1.4 wt % into the glass network. Thus, the kinetics of the hydroxyapatite (HA mineralization on the glass prepared in the alumina crucible was found to be slower than that reported for the same glass composition prepared in a Pt crucible. It is considered that the synthesis conditions lead to the incorporation of small amount of aluminum into the BG network and thus delay the HA mineralization. Interestingly, the BG-gly paste was shown to have significantly higher bioactivity than that of the as-prepared BG. Structural analysis of the paste indicate that glycerol chemically interacts with the glass surface and strongly alter the glass network architecture, thus generating a more depolymerized network, as well as an increased amount of silanol groups at the surface of the glass. In particular, BG-gly paste features early intermediate calcite precipitation during immersion in SBF, followed by hydroxyapatite formation after ca. seven days of SBF exposure; whereas the HA mineralization seems to be suppressed in BG, probably a consequence of the incorporation of aluminum into the glass network. The results obtained within the present study reveal the positive effect of using pastes based on bioactive glasses and organic carriers (here alcohols which may be of interest not only due to their advantageous visco-elastic properties, but also due to the possibility of enhancing the glass bioactivity upon surface interactions with the organic carrier.

  4. Fabrication and bioactivity behavior of HA/bioactive glass composites in the presence of calcium hexaboride

    Energy Technology Data Exchange (ETDEWEB)

    El-Bassyouni, Gehan T.; Beherei, Hanan H. [Biomaterials Dept., National Research Centre (NRC), Dokki, Cairo (Egypt); Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre (NRC), Dokki, Cairo (Egypt); Kenawy, Sayed H. [Ceramics Dept., National Research Centre (NRC), Dokki, Cairo (Egypt)

    2016-06-01

    In the current study, composites were prepared using both the synthesized nano-sized hydroxyapatite (HA), bioactive glass (BG) powders (obtained by the traditional melt-quenching route) together with the purchased nano-sized calcium hexaboride (CB) with different ratios and were fired at 1250 °C. The structure and composition of the solid reaction products were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy; scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS), transmission electron microscope (TEM) techniques and compressive strength. The mechanical testing was to designate the role of the CB in improving the mechanical property of the prepared composites. In vitro bioactivity of the prepared composites was assessed by soaking in the simulated body fluid (SBF) at 37 ± 0.5 °°C for 10 days. The effect of different ratios of the three components (CB, HA & BG) on the bioactivity properties was assessed to explore the possibility of enhancing such property to perform in vitro imitations of in vivo conditions in the future. It can be pointed out that the Si-HA content in the composition showed outstanding in vitro bioactivity than pure hydroxyapatite which could be attributed to the excellent bioactivity of the synthesized composites. - Highlights: • The prepared of nano-composites containing CB, HA and BG powders were achieved. • The addition of CB powder enhanced the compressive strength for all the composites. • The composites containing high BG and CB contents improved formation of bone-like apatite layer.

  5. Fabrication and bioactivity behavior of HA/bioactive glass composites in the presence of calcium hexaboride

    International Nuclear Information System (INIS)

    El-Bassyouni, Gehan T.; Beherei, Hanan H.; Mohamed, Khaled R.; Kenawy, Sayed H.

    2016-01-01

    In the current study, composites were prepared using both the synthesized nano-sized hydroxyapatite (HA), bioactive glass (BG) powders (obtained by the traditional melt-quenching route) together with the purchased nano-sized calcium hexaboride (CB) with different ratios and were fired at 1250 °C. The structure and composition of the solid reaction products were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy; scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS), transmission electron microscope (TEM) techniques and compressive strength. The mechanical testing was to designate the role of the CB in improving the mechanical property of the prepared composites. In vitro bioactivity of the prepared composites was assessed by soaking in the simulated body fluid (SBF) at 37 ± 0.5 °°C for 10 days. The effect of different ratios of the three components (CB, HA & BG) on the bioactivity properties was assessed to explore the possibility of enhancing such property to perform in vitro imitations of in vivo conditions in the future. It can be pointed out that the Si-HA content in the composition showed outstanding in vitro bioactivity than pure hydroxyapatite which could be attributed to the excellent bioactivity of the synthesized composites. - Highlights: • The prepared of nano-composites containing CB, HA and BG powders were achieved. • The addition of CB powder enhanced the compressive strength for all the composites. • The composites containing high BG and CB contents improved formation of bone-like apatite layer.

  6. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    Energy Technology Data Exchange (ETDEWEB)

    Rojaee, Ramin, E-mail: raminrojaee@aim.com [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Fathi, Mohammadhossein [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Raeissi, Keyvan [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)

    2013-11-15

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF{sub 2} conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  7. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    International Nuclear Information System (INIS)

    Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

    2013-01-01

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF 2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  8. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    Science.gov (United States)

    Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

    2013-11-01

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  9. Technologies for enhancement of bioactive components and potential health benefits of cereal and cereal-based foods: Research advances and application challenges.

    Science.gov (United States)

    Saleh, Ahmed S M; Wang, Peng; Wang, Na; Yang, Shu; Xiao, Zhigang

    2017-08-28

    Cereal grains are a major source of human food and their production has steadily been increased during the last several decades to meet the demand of our increasing world population. The modernized society and the expansion of the cereal food industry created a need for highly efficient processing technologies, especially flour production. Earlier scientific research efforts have led to the invention of the modern steel roller mill, and the refined flour of wheat has become a basic component in most of cereal-based foods such as breads and pastries because of the unique functionality of wheat protein. On the other hand, epidemiological studies have found that consumption of whole cereal grains was health beneficial. The health benefit of whole cereal grain is attributed to the combined effects of micronutrients, phytochemicals, and dietary fibre, which are mainly located in the outer bran layer and the germ. However, the removal of bran and germ from cereal grains during polishing and milling results in refined flour and food products with lower bioactive compounds and dietary fibre contents than those from whole grain. Also, the level of bioactive compounds in cereal food is influenced by other food preparation procedures such as baking, cooking, extrusion, and puffing. Therefore, food scientists and nutritionists are searching for strategies and processing technologies to enhance the content and bioavailability of nutrients, bioactive compounds, and dietary fibre of cereal foods. The objective of this article was to review the research advances on technologies for the enhancement of bioactive compounds and dietary fibre contents of cereal and cereal-based foods. Bioactivities or biological effects of enhanced cereal and cereal-based foods are presented. Challenges facing the application of the proposed technologies in the food industry are also discussed.

  10. Vascular and micro-environmental influences on MSC-coral hydroxyapatite construct-based bone tissue engineering.

    Science.gov (United States)

    Cai, Lei; Wang, Qian; Gu, Congmin; Wu, Jingguo; Wang, Jian; Kang, Ning; Hu, Jiewei; Xie, Fang; Yan, Li; Liu, Xia; Cao, Yilin; Xiao, Ran

    2011-11-01

    Bone tissue engineering (BTE) has been demonstrated an effective approach to generate bone tissue and repair bone defect in ectopic and orthotopic sites. The strategy of using a prevascularized tissue-engineered bone grafts (TEBG) fabricated ectopically to repair bone defects, which is called live bone graft surgery, has not been reported. And the quantitative advantages of vascularization and osteogenic environment in promoting engineered bone formation have not been defined yet. In the current study we generated a tissue engineered bone flap with a vascular pedicle of saphenous arteriovenous in which an organized vascular network was observed after 4 weeks implantation, and followed by a successful repaire of fibular defect in beagle dogs. Besides, after a 9 months long term observation of engineered bone formation in ectopic and orthotopic sites, four CHA (coral hydroxyapatite) scaffold groups were evaluated by CT (computed tomography) analysis. By the comparison of bone formation and scaffold degradation between different groups, the influences of vascularization and micro-environment on tissue engineered bone were quantitatively analyzed. The results showed that in the first 3 months vascularization improved engineered bone formation by 2 times of non-vascular group and bone defect micro-environment improved it by 3 times of ectopic group, and the CHA-scaffold degradation was accelerated as well. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Biomineralization-inspired synthesis of chitosan/hydroxyapatite biocomposites based on a novel bilayer rate-controlling model.

    Science.gov (United States)

    Hu, Jing-Xiao; Ran, Jia-Bing; Chen, Si; Shen, Xin-Yu; Tong, Hua

    2015-12-01

    In order to prepare sophisticated biomaterials using a biomimetic approach, a deeper understanding of biomineralization is needed. Of particular importance is the control and regulation of the mineralization process. In this study, a novel bilayer rate-controlling model was designed to investigate the factors potentially influencing mineralization. In the absence of a rate-controlling layer, nano-scale hydroxyapatite (HA) crystallites exhibited a spherical morphology, whereas, in the presence of a rate-controlling layer, HA crystallites were homogeneously dispersed and spindle-like in structure. The mineralization rate had a significant effect on controlling the morphology of crystals. Furthermore, in vitro tests demonstrated that the reaction layer containing spindle-like HA crystallites possessed superior biological properties. These results suggest that a slow mineralization rate is required for controlling the morphology of inorganic crystallites, and consumption by the rate-controlling layer ensured that the ammonia concentration remained low. This study demonstrates that a biomimetic approach can be used to prepare novel biomaterials containing HA crystallites that have different morphologies and biological properties. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Effect of Sr on the bioactivity and corrosion resistance of nanoporous niobium oxide coating for orthopaedic applications

    International Nuclear Information System (INIS)

    Pauline, S. Anne; Rajendran, N.

    2014-01-01

    In this study, strontium incorporated Nb 2 O 5 was synthesized in two different proportions by sol–gel methodology and was deposited on 316L SS by spin coating method. The synthesis conditions were optimized to obtain a nanoporous morphology. The prepared Sr-incorporated Nb 2 O 5 coatings were uniform, smooth and well adherent on to the substrate 316L SS. The coatings were characterized by attenuated total reflectance-infrared spectroscopy (ATR-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and transmission electron microscopy (TEM) and the formation of Sr-incorporated Nb 2 O 5 coatings with nanoporous morphology was confirmed. Static water contact angle measurements showed an enhancement in the wettability of the obtained coatings. In vitro bioactivity test of the coated substrates showed that 0.05 M Sr-incorporated Nb 2 O 5 coating had better bioactivity compared to 0.1 M Sr-incorporated coating. Solution analysis studies confirmed the controlled release of Sr ions from the coating, which aid and enhance hydroxyapatite (HAp) growth. Electrochemical studies confirmed that the coatings provided excellent corrosion protection to the base material as increased charge transfer resistance and decreased double layer capacitance was observed for the coated substrates. - Highlights: • Nanoporous Sr-incorporated Nb 2 O 5 coatings were deposited on 316L SS. • The coatings have excellent bond strength and high Vickers micro hardness value. • Nanoporous 0.05 M Sr-incorporated Nb 2 O 5 coating showed hydroxyapatite growth. • Slow release of strontium from the coating accelerated hydroxyapatite growth. • The nanoporous coatings offered excellent corrosion protection to 316L SS

  13. Effect of Sr on the bioactivity and corrosion resistance of nanoporous niobium oxide coating for orthopaedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Pauline, S. Anne; Rajendran, N., E-mail: nrajendran@annauniv.edu

    2014-03-01

    In this study, strontium incorporated Nb{sub 2}O{sub 5} was synthesized in two different proportions by sol–gel methodology and was deposited on 316L SS by spin coating method. The synthesis conditions were optimized to obtain a nanoporous morphology. The prepared Sr-incorporated Nb{sub 2}O{sub 5} coatings were uniform, smooth and well adherent on to the substrate 316L SS. The coatings were characterized by attenuated total reflectance-infrared spectroscopy (ATR-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and transmission electron microscopy (TEM) and the formation of Sr-incorporated Nb{sub 2}O{sub 5} coatings with nanoporous morphology was confirmed. Static water contact angle measurements showed an enhancement in the wettability of the obtained coatings. In vitro bioactivity test of the coated substrates showed that 0.05 M Sr-incorporated Nb{sub 2}O{sub 5} coating had better bioactivity compared to 0.1 M Sr-incorporated coating. Solution analysis studies confirmed the controlled release of Sr ions from the coating, which aid and enhance hydroxyapatite (HAp) growth. Electrochemical studies confirmed that the coatings provided excellent corrosion protection to the base material as increased charge transfer resistance and decreased double layer capacitance was observed for the coated substrates. - Highlights: • Nanoporous Sr-incorporated Nb{sub 2}O{sub 5} coatings were deposited on 316L SS. • The coatings have excellent bond strength and high Vickers micro hardness value. • Nanoporous 0.05 M Sr-incorporated Nb{sub 2}O{sub 5} coating showed hydroxyapatite growth. • Slow release of strontium from the coating accelerated hydroxyapatite growth. • The nanoporous coatings offered excellent corrosion protection to 316L SS.

  14. Bioactivity and mineralization of hydroxyapatite with bioglass as sintering aid and bioceramics with Na{sub 3}Ca{sub 6}(PO{sub 4}){sub 5} and Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4} in a silicate matrix

    Energy Technology Data Exchange (ETDEWEB)

    Demirkiran, Hande [Materials Science and Engineering Department, University of Texas at Arlington, Arlington, TX 76019 (United States); Mohandas, Arunesh; Dohi, Motokazi; Fuentes, Alonso; Nguyen, Kytai [Bioengineering Department, University of Texas at Arlington, Arlington, TX 76019 (United States); Aswath, Pranesh, E-mail: aswath@uta.edu [Materials Science and Engineering Department, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2010-01-30

    Hydroxyapatite and Bioglass-45S5 were sintered together creating new ceramic compositions that yielded increased apatite deposition and osteoblast differentiation and proliferation in vitro compared to hydroxyapatite. The sintered products characterized by X-ray diffraction, revealed hydroxyapatite as the main phase when small quantities (1, 2.5 and 5 wt.%) of bioglass was added. Bioglass behaved as a sintering aid with {beta}-TCP (Ca{sub 3}(PO{sub 4}){sub 2}) being the minor phase. The amount of {beta}-TCP increased with the amount of bioglass added. In compositions with larger additions of bioglass (10 and 25 wt.%), new phases with compositions of calcium phosphate silicate (Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4}) and sodium calcium phosphate (Na{sub 3}Ca{sub 6}(PO{sub 4}){sub 5}) were formed respectively within amorphous silicate matrices. In vitro cell culture studies of the ceramic compositions were examined using bone marrow stromal cell (BMSC). Cell proliferation and differentiation of bone marrow stromal cells into osteoblasts were determined by Pico Green DNA assays and alkaline phosphatase (ALP) activity, respectively. All hydroxyapatite-bioglass co-sintered ceramics exhibited larger cell proliferation compared to pure hydroxyapatite samples. After 6 days in cell culture, the ceramic with Ca{sub 5}(PO{sub 4}){sub 3}SiO{sub 4} in a silicate matrix formed by reacting hydroxyapatite with 10 wt.% bioglass exhibited the maximum proliferation of the BMSC's. The ALP activity was found to be largest in the ceramic with Na{sub 3}Ca{sub 6}(PO{sub 4}){sub 5} embedded in a silicate matrix synthesized by reacting hydroxyapatite with 25 wt.% bioglass.

  15. Study on radiation grafting reaction of MMA onto hydroxyapatite

    International Nuclear Information System (INIS)

    Jiang Bo

    1996-01-01

    The grafting reaction of MMA onto hydroxyapatite has been studied with the pre-irradiation method in air. The effects of radiation dose, monomer concentration, reaction temperature and inorganic acid on the system are observed. The grafting copolymerization is found to be controlled by the kinetics. If proper kinetic conditions are selected, a better grafting yield can be obtained. Employing weight method, burning method as well as SeM and IR analysis, it has been proved that MMA is definitely grafted onto hydroxyapatite by chemical bonds, which shows that it is possible to improve the interface of inorganic-organic composite materials and to make bioactive ceramics by using radiation induced-grafting copolymerization

  16. Alendronate functionalized mesoporous hydroxyapatite nanoparticles for drug delivery

    International Nuclear Information System (INIS)

    Li, Dongdong; Zhu, Yuntao; Liang, Zhiqiang

    2013-01-01

    Highlights: ► The synthesized mesoporous hydroxyapatite has nanostructure and bioactivity. ► The materials have high surface area and amino group. ► The materials show higher drug loading and slower release rate than pure HAP. - Abstract: Mesoporous nanosized hydroxyapatite (HAP) functionalized by alendronate (ALN) was synthesized using cationic surfactant CTAB as template. The structural, morphological and textural properties were fully characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and N 2 adsorption/desorption. Then the obtained materials were performed as drug delivery carriers using ibuprofen (IBU) as a model drug to investigate their drug storage/release properties in simulated body fluid (SBF). The materials showed relatively slower release rate compared with HAP due to the ionic interaction between -NH 3 + on the matrix and -COO − belongs to IBU. The system provides a new concept for improving the drug loading or slowing down the release rate

  17. Synthesis and characterization of hydroxyapatite-doped silver nanoparticles

    International Nuclear Information System (INIS)

    Andrade, Flavio Augusto Cavadas da Silva; Rollo, Joao Manuel Domingos de Almeida; Rigo, Eliana Cristina da Silva; Vercik, Andres; Vercik, Luci Cristina de Oliveira; Valencia, German Ayala; Ferreira, Leticcia Gaviao

    2012-01-01

    Hydroxyapatite-doped silver nanoparticles was obtained by immersing the powder in increasing dilutions of a solution containing AGNPS which were synthesized in different times and were characterized by UV-vis spectroscopy. The X-ray diffraction (XRD)studies demonstrate no change in the major phase of HA. Scanning Electron Microscopy (SEM) revealed morphological characteristics of powders after doping and the presence of silver was confirmed by energy dispersive X-ray (EDAX) analysis.The antibacterial effect of the doped powders was evaluated using strain of Staphylococcus aureus by disc-diffusion test. The zone of inhibition was found to vary with the amount of silver nanoparticle in the doped powder even for low concentrations of AgNPs. These results indicate that the method of immersion hydroxyapatite in solutions containing AgNPs is promising to obtain bioactive materials with low cytotoxicity and antibacterial effects. (author)

  18. Formation of hydroxyapatite onto glasses of the CaO-MgO-SiO2 system with B2O3, Na2O, CaF2 and P2O5 additives.

    Science.gov (United States)

    Agathopoulos, S; Tulyaganov, D U; Ventura, J M G; Kannan, S; Karakassides, M A; Ferreira, J M F

    2006-03-01

    New bioactive glasses with compositions based on the CaO-MgO-SiO(2) system and additives of B(2)O(3), P(2)O(5), Na(2)O, and CaF(2) were prepared. The in vitro mineralization behaviour was tested by immersion of powders or bulk glasses in simulated body fluid (SBF). Monitoring of ionic concentrations in SBF and scanning electron microscopy (SEM) observations at the surface of the glasses were conducted over immersion time. Raman and infrared (IR) spectroscopy shed light on the structural evolution occurring at the surface of the glasses that leads to formation of hydroxyapatite.

  19. A Novel Method to Improve the Anticancer Activity of Natural-Based Hydroxyapatite against the Liver Cancer Cell Line HepG2 Using Mesoporous Magnesia as a Micro-Carrier

    OpenAIRE

    Nasser S. Awwad; Ali M. Alshahrani; Kamel A. Saleh; Mohamed S. Hamdy

    2017-01-01

    Micro-carriers are the best known vehicles to transport different kinds of drugs to achieve high impact. In this study, mesoporous magnesium oxide has been harnessed as a micro-carrier to encapsulate the anticancer candidate drug natural-based cubic hydroxyapatite (HAP). HAP@MgO composites with different HAP loading (0–60 wt %), were prepared by a hydrothermal treatment method using triethanol amine as a template. The characterization of the prepared composites were achieved by using XRD, Ram...

  20. Physicochemical, bioactive, and sensory properties of persimmon-based ice cream: technique for order preference by similarity to ideal solution to determine optimum concentration.

    Science.gov (United States)

    Karaman, Safa; Toker, Ömer Said; Yüksel, Ferhat; Çam, Mustafa; Kayacier, Ahmed; Dogan, Mahmut

    2014-01-01

    In the present study, persimmon puree was incorporated into the ice cream mix at different concentrations (8, 16, 24, 32, and 40%) and some physicochemical (dry matter, ash, protein, pH, sugar, fat, mineral, color, and viscosity), textural (hardness, stickiness, and work of penetration), bioactive (antiradical activity and total phenolic content), and sensory properties of samples were investigated. The technique for order preference by similarity to ideal solution approach was used for the determination of optimum persimmon puree concentration based on the sensory and bioactive characteristics of final products. Increase in persimmon puree resulted in a decrease in the dry matter, ash, fat, protein contents, and viscosity of ice cream mix. Glucose, fructose, sucrose, and lactose were determined to be major sugars in the ice cream samples including persimmon and increase in persimmon puree concentration increased the fructose and glucose content. Better melting properties and textural characteristics were observed for the samples with the addition of persimmon. Magnesium, K, and Ca were determined to be major minerals in the samples and only K concentration increased with the increase in persimmon content. Bioactive properties of ice cream samples improved and, in general, acetone-water extracts showed higher bioactivity compared with ones obtained using methanol-water extracts. The technique for order preference by similarity to ideal solution approach showed that the most preferred sample was the ice cream containing 24% persimmon puree. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Hydrogel-embedded nanocrystalline hydroxyapatite granules (elastic blocks based on a cross-linked polyvinylpyrrolidone as bone grafting substitute in a rat tibia model

    Directory of Open Access Journals (Sweden)

    Dau M

    2017-10-01

    Full Text Available Michael Dau,1 Cornelia Ganz,2 Franziska Zaage,2 Bernhard Frerich,1 Thomas Gerber2 1Department of Oral, Maxillofacial and Plastic Surgery, University Medical Center Rostock, Rostock, Germany; 2Institute of Physics, Rostock University, Rostock, Germany Purpose: The aim of this study was to examine the in vivo characteristics and levels of integration and degradation of a ready-to-use bone grafting block with elastic properties (elastic block for the use in surgery. Materials and methods: Thirty-six male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. All created defects – one per animal – were filled with an unsintered nanocrystalline hydroxyapatite embedded either with a non-cross-linked hydrogel carrier (CONT, n=18 or a cross-linked hydrogel carrier (elastic block [EB], n=18 based on polyvinylpyrrolidone (PVP and silica sol, respectively. The animals were killed after 12 (n=12, 21 (n=12 and 63 days (n=12. The bone formation and defect healing were quantified by histomorphometric measurements made in paraffin sections. Additionally, immunohistochemical (tartrate-resistant acid phosphatase [TRAP] and alkaline phosphatase [aP], antibody-based examinations (CD68 and energy-dispersive x-ray scattering measurements of silica atom concentration were carried out. Results: A larger remaining bone defect area overall was observed in EB after 12 days and 21 days. After 63 days, similar areas of remaining bone defects were found. The amount of the remaining carrier material in EB overall was higher at all times. In CONT no residual carrier material was found at 12 days and later. CD68 analyses showed significantly lower level of CD68-positive marked cells after 21 days in CONT, and nonsignificant differences at 12 and 63 days, respectively. Additionally, a significantly higher level of aP-positive marked cells was observed in CONT after 12 days. Later on, the levels of aP-positive marked cells were slightly higher

  2. Physicochemical and mechanical properties of freeze cast hydroxyapatite-gelatin scaffolds with dexamethasone loaded PLGA microspheres for hard tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Farnaz, E-mail: Farnaz_ghorbani.1991@yahoo.com [Department of Biomedical Engineering, Tehran Science and Research Branch, Islamic Azad University, P. O. Box: 4515/775, Tehran (Iran, Islamic Republic of); Nojehdehian, Hanieh, E-mail: hanieh.nojehdehyan@gmail.com [Department of Dental Materials, School of Dentistry, Shahid Beheshti University of Medical Sciences, P.O. Box: 1983963113, Tehran (Iran, Islamic Republic of); Zamanian, Ali, E-mail: a-zamanian@merc.ac.ir [Biomaterials Research Group, Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box: 14155-4777, Tehran (Iran, Islamic Republic of)

    2016-12-01

    Hydroxyapatite (HA)-gelatin scaffolds incorporated with dexamethasone-loaded polylactic-co-glycolic acid (PLGA) microspheres were synthesized by freeze casting technique. Scanning electron microscopy (SEM) micrographs demonstrated a unidirectional microstructure and a decrease in the pore size as a function of temperature gradient. Higher amounts of HA resulted in a decrease in the pore size. According to the results, at lower cooling rates, the formation of a lamellar structure decreased the mechanical strength, but at the same time, enhanced the swelling ratio, biodegradation rate and drug release level. On the other hand, higher weight ratios of HA increased the compressive strength, and reduced the swelling ratio, biodegradation rate and drug release level. The results obtained by furrier transform infrared spectroscopy (FTIR) and bioactivity analysis illustrated that the interactions of the materials support the apatite formation in the simulated body fluid (SBF) solution. Based on the obtained results, the synthesized composite scaffolds have the necessary mechanical and physicochemical features to support the regeneration of defects and to maintain their stability during the neo-tissue formation. - Highlights: • Freeze casting technique created unidirectional lamellar type microstructure. • Unidirectional microstructure of samples improved mechanical behavior, absorption, biodegradation rate and release behavior. • Hydroxyapatite-gelatin scaffolds demonstrated bioactive behavior and support new apatite layer formation. • Controlled release rate provided by dexamethasone loaded PLGA microspheres.

  3. Identification of nevadensin as an important herb-based constituent inhibiting estragole bioactivation and physiology-based biokinetic modeling of its possible in vivo effect

    International Nuclear Information System (INIS)

    Alhusainy, W.; Paini, A.; Punt, A.; Louisse, J.; Spenkelink, A.; Vervoort, J.; Delatour, T.; Scholz, G.; Schilter, B.; Adams, T.; Bladeren, P.J. van; Rietjens, I.M.C.M.

    2010-01-01

    Estragole is a natural constituent of several herbs and spices including sweet basil. In rodent bioassays, estragole induces hepatomas, an effect ascribed to estragole bioactivation to 1'-sulfooxyestragole resulting in DNA adduct formation. The present paper identifies nevadensin as a basil constituent able to inhibit DNA adduct formation in rat hepatocytes exposed to the proximate carcinogen 1'-hydroxyestragole and nevadensin. This inhibition occurs at the level of sulfotransferase (SULT)-mediated bioactivation of 1'-hydroxyestragole. The Ki for SULT inhibition by nevadensin was 4 nM in male rat and human liver fractions. Furthermore, nevadensin up to 20 μM did not inhibit 1'-hydroxyestragole detoxification by glucuronidation and oxidation. The inhibition of SULT by nevadensin was incorporated into the recently developed physiologically based biokinetic (PBBK) rat and human models for estragole bioactivation and detoxification. The results predict that co-administration of estragole at a level inducing hepatic tumors in vivo (50 mg/kg bw) with nevadensin at a molar ratio of 0.06, representing the ratio of their occurrence in basil, results in almost 100% inhibition of the ultimate carcinogen 1'-sulfooxyestragole when assuming 100% uptake of nevadensin. Assuming 1% uptake, inhibition would still amount to more than 83%. Altogether these data point at a nevadensin-mediated inhibition of the formation of the ultimate carcinogenic metabolite of estragole, without reducing the capacity to detoxify 1'-hydroxyestragole via glucuronidation or oxidation. These data also point at a potential reduction of the cancer risk when estragole exposure occurs within a food matrix containing SULT inhibitors compared to what is observed upon exposure to pure estragole.

  4. Immobilisation of hydroxyapatite-collagen on polydopamine grafted stainless steel 316L: Coating adhesion and in vitro cells evaluation.

    Science.gov (United States)

    Tapsir, Zafirah; Jamaludin, Farah H; Pingguan-Murphy, Belinda; Saidin, Syafiqah

    2018-02-01

    The utilisation of hydroxyapatite and collagen as bioactive coating materials could enhance cells attachment, proliferation and osseointegration. However, most methods to form crystal hydroxyapatite coating do not allow the incorporation of polymer/organic compound due to production phase of high sintering temperature. In this study, a polydopamine film was used as an intermediate layer to immobilise hydroxyapatite-collagen without the introduction of high sintering temperature. The surface roughness, coating adhesion, bioactivity and osteoblast attachment on the hydroxyapatite-collagen coating were assessed as these properties remains unknown on the polydopamine grafted film. The coating was developed by grafting stainless steel 316L disks with a polydopamine film. Collagen type I fibres were then immobilised on the grafted film, followed by the biomineralisation of hydroxyapatite. The surface roughness and coating adhesion analyses were later performed by using AFM instrument. An Alamar Blue assay was used to determine the cytotoxicity of the coating, while an alkaline phosphatase activity test was conducted to evaluate the osteogenic differentiation of human fetal osteoblasts on the coating. Finally, the morphology of cells attachment on the coating was visualised under FESEM. The highest RMS roughness and coating adhesion were observed on the hydroxyapatite-collagen coating (hydroxyapatite-coll-dopa). The hydroxyapatite-coll-dopa coating was non-toxic to the osteoblast cells with greater cells proliferation, greater level of alkaline phosphate production and more cells attachment. These results indicate that the immobilisation of hydroxyapatite and collagen using an intermediate polydopamine is identical to enhance coating adhesion, osteoblast cells attachment, proliferation and differentiation, and thus could be implemented as a coating material on orthopaedic and dental implants.

  5. Cadmium immobilization by hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Smičiklas Ivana D.

    2003-01-01

    Full Text Available The contamination of air, soil and water by cadmium is a great environmental problem. If cadmium occurs in nature in ionic form, soluble in water, it easily enters into the food chain. Hydroxyapatite (HAP, Ca-o(POAe(OH2 is a sparingly soluble salt and an excellent matrix for the removal of heavy metals from solutions. Considerable research attention has been paid to the bond between Cc/2+ ions and synthetic hydroxyapatite of known composition. The sorption mechanism is complex. The dominant process is ion exchange, but surface adsorption, surface complexation and coprecipitation can also contribute to the overall mechanism. The sorption capacity depends on the characteristics of hydroxyapatite itself and on the experimental conditions. Under optimum conditions a maximum capacity of 0.8 mol Cd2+/mol HAP can be achieved. HAP is a potential sorbent for the remediation of contaminated water and soil, for industrial waste treatment, and it is also referenced as a material that can be used as a barrier around waste depositories.

  6. Synthesis and characterization of nanocrystalline hydroxyapatite gel and its application as scaffold aggregation

    OpenAIRE

    Rodrigues, Leonardo Ribeiro; d` Ávila, Marcos Akira; Monteiro, Fernando Jorge Mendes; Zavaglia, Cecília Amélia de Carvalho

    2012-01-01

    The sol-gel process is a technique used to synthesize materials from colloidal suspensions and, therefore, is suitable for preparing materials in the nanoscale. In this work hydroxyapatite was used due to its known properties in tissue engineering. Hydroxyapatite Ca10(PO4)6(OH)2 is a bioactive ceramic which is found in the mineral phase of bone tissue and is known for its great potential in tissue engineering applications. For this reason, this material can be applied as particle aggregates o...

  7. [Synthesis and characteristics of porous hydroxyapatite bioceramics].

    Science.gov (United States)

    Niu, Jinlong; Zhang, Zhenxi; Jiang, Dazong

    2002-06-01

    The macroporous structure of human bone allows the ingrowth of the soft tissues and organic cells into the bone matrix, profits the development and metabolism of bone tissue, and adapts the bone to the change of load. There is great requirement for artificial biomimic porous bioactive ceramics with the similar structure of bone tissue that can be used clinically for repairing lost bone. Fine hydroxyapatite (HAp) powder produced by wet chemical reaction was mixed with hydrogen peroxide (H2O2), polyvinyl alcohol, methyl cellulose or other pores-making materials to form green cake. After drying at low temperature (below 100 degrees C) and decarbonizing at about 300 degrees C-400 degrees C, the spongy ceramic block was sintered at high temperature, thus, macroporous HAp bioceramic with interconnected pores and reasonable porosity and pore-diameter was manufactured. This kind of porous HAp bioceramics were intrinsically osteoinductive to a certain degree, but its outstanding property was that they can absorb human bone morphogenetic proteins and other bone growth factors to form composites, so that the macroporous HAp bioactive ceramic has appropriate feasibility for clinical application. From the point of biomedical application, the recent developments in synthesis and characteristics investigation of macroporous HAp are reviewed in this paper.

  8. Low-Cost and Scaled-Up Production of Fluorine-Free, Substrate-Independent, Large-Area Superhydrophobic Coatings Based on Hydroxyapatite Nanowire Bundles.

    Science.gov (United States)

    Chen, Fei-Fei; Yang, Zi-Yue; Zhu, Ying-Jie; Xiong, Zhi-Chao; Dong, Li-Ying; Lu, Bing-Qiang; Wu, Jin; Yang, Ri-Long

    2018-01-09

    To date, the scaled-up production and large-area applications of superhydrophobic coatings are limited because of complicated procedures, environmentally harmful fluorinated compounds, restrictive substrates, expensive equipment, and raw materials usually involved in the fabrication process. Herein, the facile, low-cost, and green production of superhydrophobic coatings based on hydroxyapatite nanowire bundles (HNBs) is reported. Hydrophobic HNBs are synthesised by using a one-step solvothermal method with oleic acid as the structure-directing and hydrophobic agent. During the reaction process, highly hydrophobic C-H groups of oleic acid molecules can be attached in situ to the surface of HNBs through the chelate interaction between Ca 2+ ions and carboxylic groups. This facile synthetic method allows the scaled-up production of HNBs up to about 8 L, which is the largest production scale of superhydrophobic paint based on HNBs ever reported. In addition, the design of the 100 L reaction system is also shown. The HNBs can be coated on any substrate with an arbitrary shape by the spray-coating technique. The self-cleaning ability in air and oil, high-temperature stability, and excellent mechanical durability of the as-prepared superhydrophobic coatings are demonstrated. More importantly, the HNBs are coated on large-sized practical objects to form large-area superhydrophobic coatings. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Preparation and optimization of submicron chitosan capsules by water-based electrospraying for food and bioactive packaging applications.

    Science.gov (United States)

    Sreekumar, Sruthi; Lemke, Philipp; Moerschbacher, Bruno M; Torres-Giner, Sergio; Lagaron, Jose M

    2017-10-01

    In the present study, a well-defined set of chitosans, with different degrees of acetylation (DA) and degrees of polymerization (DP), were processed by solution electrospraying from a water-based solvent. The solution properties, in terms of surface tension, conductivity, viscosity, and pH, were characterized and related to the physico-chemical properties of the chitosans. It was observed that both DA and DP values of a given chitosan, in combination with biopolymer concentration, mainly determined solution viscosity. This was, in turn, the major driving factor that defined the electrosprayability of chitosan. In addition, the physico-chemical properties of chitosans highly influenced solution conductivity and results indicated that the chitosan solutions with low or low-to-medium values of conductivity were the most optimal for electrospraying. The results obtained here also demonstrate that a good process control can be achieved by adjusting the working conditions, i.e. applied voltage, flow-rate, and tip-to-collector distance. Finally, it was also shown that electrosprayability of chitosan with inadequate physico-chemical properties can be improved by solution mixing of very different kinds of this polysaccharide. The resultant electrosprayed submicron chitosan capsules can be applied for encapsulation of food additives and to develop bioactive coatings of interest in food packaging, where these particles alone or containing functional ingredients can be released from the package into the food to promote a health benefit.

  10. Thermoluminescence as a probe in bioactivity studies; the case of 58S sol-gel bioactive glass

    International Nuclear Information System (INIS)

    Polymeris, George S; Tsirliganis, Nestor C; Goudouri, Ourania Menti; Paraskevopoulos, Konstantinos M; Kontonasaki, Eleana; Kitis, George

    2011-01-01

    The formation of a carbonated hydroxyapatite (HCAp) layer on the surface of bioactive materials is the main reaction that takes place upon their immersion in physiological fluids. To date, all techniques used for the identification of this HCAp formation are rather time consuming and not well suited to detailed and rapid monitoring of changes in the bioactivity response of the material. The aim of this work is to explore the possibility of using thermoluminescence (TL) for the discrimination between different bioactive responses in the case of the 58S bioactive glass. Results provided strong indications that the 110 deg. C TL peak of quartz can be used effectively in the study of the bioactive behaviour of 58S bioactive glass, since it is unambiguously present in all samples and does not require deconvolution analysis. Furthermore, the intensity of the 110 deg. C TL peak is proven to be very sensitive to the different bioactive responses, identifying the loss of silica which takes place at the first stages of the sequence. The discontinuities of the 110 deg. C TL peak intensity plot versus immersion time at 8 and 1440 min provide experimental indications regarding the timescale for both the beginning of amorphous CaP formation as well as the end of crystalline hydroxyl-apatite formation respectively, while the spike in the sensitization of the 110 deg. C TL peak, which was observed for immersion times ranging between 20 and 40 min, could be an experimental feature indicating the beginning of the crystalline HCAp formation.

  11. Zinc and Carbonate Co-Substituted Nano-Hydroxyapatite

    Science.gov (United States)

    Girija, E. K.; Kumar, G. Suresh; Thamizhavel, A.

    2011-07-01

    Synthesis of Zn or CO32- substituted nano-hydroxyapatite (HA) and its physico-chemical properties have been well documented. However, the effects of the simultaneous substitution of Zn and CO32- in nano-HA have not been reported. In the present study, Zn and CO32- substitutions in nano HA independently and concurrently have been done by wet precipitation method and characterized by XRD and FT-IR for its phase purity and chemical homogeneity. Further modulations of the bioactivity and thermal stability of HA due to the substitutions have been studied.

  12. Biocompatibility and biomechanical characteristics of loofah based scaffolds combined with hydroxyapatite, cellulose, poly-L-lactic acid with chondrocyte-like cells

    International Nuclear Information System (INIS)

    Cecen, Berivan; Kozaci, Leyla Didem; Yuksel, Mithat; Ustun, Ozcan; Ergur, Bekir Ugur; Havitcioglu, Hasan

    2016-01-01

    The current study reports the biocompatibility and biomechanical characteristics of loofah-based scaffolds combined with hydroxyapatite (HA), cellulose, poly-L-lactic acid (PLLA) with chondrocytes-like cells. Scanning electron microscope (SEM) micrographs of the scaffolds showed that the addition of PLLA usually resulted in an increase in cell's attachment on scaffolds. Mechanical and elemental analyzes were assessed using tensile test and Energy Dispersive X-ray spectrometry (EDS), respectively. In summary, we showed that the loofah + PLLA + HA scaffolds perform significantly better than other loofah–based scaffolds employed in terms of increasing a diversity of mechanical properties including tensile strength and Young's modulus. Based on the analysis of the differential scanning calorimetry (DSC) thermograms and EDS spectrums that give an idea about the calcium phosphate (CaP) ratios, the improvement in the mechanical properties could principally be recognized to the strong interaction formed between loofah, PLLA and HA. The viability of chondrocytes on loofah–based scaffolds was analyzed by XTT tests. However, none of the scaffolds have proved to be toxic in metabolic activity. The histological evaluation obtained by hematoxylin and eosin (H&E), Masson trichrome, toluidine blue and immunohistochemistry methods showed that cells in all scaffolds produced extracellular matrix that defined proteoglycan and type I-II collagens. The results of this study suggest that the loofah-based scaffold with desirable properties can be considered as an ideal candidate for cartilage tissue engineering applications. - Highlights: • In this study we designed a new scaffold and characterized it using biochemical and biomechanical assays. • Our manuscript with the novelty of the scaffold design will add new perspective in the literature about loofah based scaffolds. • The objective of the study is to investigate the natural and novel loofah based scaffolds with

  13. Biocompatibility and biomechanical characteristics of loofah based scaffolds combined with hydroxyapatite, cellulose, poly-L-lactic acid with chondrocyte-like cells

    Energy Technology Data Exchange (ETDEWEB)

    Cecen, Berivan, E-mail: berivan.erik@deu.edu.tr [Dokuz Eylul University, The Institute of Health Science, Department of Biomechanics, 35340 Izmir (Turkey); Kozaci, Leyla Didem [Yildirim Beyazit University, Medical Faculty, Department of Medical Biochemistry, 06800 Ankara (Turkey); Yildirim Beyazit University, Musculoskeletal System Studies Research Center, 06800 Ankara (Turkey); Yuksel, Mithat [Ege University, Engineering Faculty, Department of Chemical Engineering, 35100 Izmir (Turkey); Ustun, Ozcan; Ergur, Bekir Ugur [Dokuz Eylul University, Department of Histology & Embryology, 35340 Izmir (Turkey); Havitcioglu, Hasan [Dokuz Eylul University, The Institute of Health Science, Department of Biomechanics, 35340 Izmir (Turkey); Dokuz Eylul University, Medicine Faculty, Department of Orthopaedics and Traumatology, 35340 Izmir (Turkey)

    2016-12-01

    The current study reports the biocompatibility and biomechanical characteristics of loofah-based scaffolds combined with hydroxyapatite (HA), cellulose, poly-L-lactic acid (PLLA) with chondrocytes-like cells. Scanning electron microscope (SEM) micrographs of the scaffolds showed that the addition of PLLA usually resulted in an increase in cell's attachment on scaffolds. Mechanical and elemental analyzes were assessed using tensile test and Energy Dispersive X-ray spectrometry (EDS), respectively. In summary, we showed that the loofah + PLLA + HA scaffolds perform significantly better than other loofah–based scaffolds employed in terms of increasing a diversity of mechanical properties including tensile strength and Young's modulus. Based on the analysis of the differential scanning calorimetry (DSC) thermograms and EDS spectrums that give an idea about the calcium phosphate (CaP) ratios, the improvement in the mechanical properties could principally be recognized to the strong interaction formed between loofah, PLLA and HA. The viability of chondrocytes on loofah–based scaffolds was analyzed by XTT tests. However, none of the scaffolds have proved to be toxic in metabolic activity. The histological evaluation obtained by hematoxylin and eosin (H&E), Masson trichrome, toluidine blue and immunohistochemistry methods showed that cells in all scaffolds produced extracellular matrix that defined proteoglycan and type I-II collagens. The results of this study suggest that the loofah-based scaffold with desirable properties can be considered as an ideal candidate for cartilage tissue engineering applications. - Highlights: • In this study we designed a new scaffold and characterized it using biochemical and biomechanical assays. • Our manuscript with the novelty of the scaffold design will add new perspective in the literature about loofah based scaffolds. • The objective of the study is to investigate the natural and novel loofah based scaffolds with

  14. Green chemistry approach to the synthesis of potentially bioactive aminobenzylated Mannich bases through active hydrogen compounds

    Directory of Open Access Journals (Sweden)

    S. L. VASOYA

    2005-10-01

    Full Text Available An efficient and high yield method for the synthesis of aminobenzylated Mannich bases is described. The synthesis occurs in aqueous medium at 0 ºC. The compounds show moderate antitubercular and antimicrobial activities.

  15. Formation of Biomimetic Hydroxyapatite Coating on Titanium Plates

    Directory of Open Access Journals (Sweden)

    Ievgen Volodymyrovych PYLYPCHUK

    2014-09-01

    Full Text Available Hydroxyapatite (HA has long been used as a coating material in the implant industry for orthopedic implant applications. HA is the natural inorganic constituent of bone and teeth. By coating titanium (base material of implant engineering because of its lightness and durability with hydroxyapatite, we can provide higher biocompatibility of titanium implants, according to HA ability to form a direct biochemical bond with living tissues. This article reports a biomimetic approach for coating hydroxyapatite with titanium A method of modifying the surface of titanium by organic modifiers (for creating functional groups on the surface, followed by formation "self-assembled" layer of biomimetic hydroxyapatite in simulated body fluid (SBF. FTIR and XPS confirmed the formation of hydroxyapatite coatings on titanium surface. Comparative study of the formation of HA on the surface of titanium plates modified by different functional groups: Ti(≡OH, Ti/(≡Si-OH and Ti/(≡COOH is conducted. It was found that the closest to natural stoichiometric hydroxyapatite Ca/P ratio was obtained on Ti/(≡COOH samples. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4974

  16. Design of polymer-biopolymer-hydroxyapatite biomaterials for bone tissue engineering: Through molecular control of interfaces

    Science.gov (United States)

    Verma, Devendra

    In this dissertation, novel biomaterials are designed for bone biomaterials and bone tissue engineering applications. Novel biomaterials of hydroxyapatite with synthetic and natural polymers have been fabricated using a combination of processing routes. Initially, we investigated hydroxyapatite-polycaprolactone-polyacrylic acid composites and observed that minimal interfacial interactions between polymer and mineral led to inadequate improvement in the mechanical properties. Bioactivity experiments on these composites showed that the presence of functional groups, such as carboxylate groups, influence bioactivity of the composites. We have developed and investigated composites of hydroxyapatite with chitosan and polygalacturonic acid (PgA). Chitosan and PgA are biocompatible, biodegradable, and also electrostatically complementary to each other. This strategy led to significant improvement in mechanical properties of new composites. The nanostructure analysis using atomic force microscopy revealed a multilevel organization in these composites. Enhancement in mechanical response was attributed to stronger interfaces due to strong electrostatic interaction between oppositely charged chitosan and PgA. Further analysis using the Rietveld method showed that biopolymers have marked impact on hydroxyapatite crystal growth and also on its crystal structure. Significant changes were observed in the lattice parameters of hydroxyapatite synthesized by following biomineralization method (organics mediated mineralization). For scaffold preparation, chitosan and PgA were mixed first, and then, nano-hydroxyapatite was added. Oppositely charged polyelectrolytes, such as chitosan and PgA, spontaneously form complex upon mixing. The poly-electrolyte complex exists as nano-sized particles. Chitosan/PgA scaffolds with and without hydroxyapatite were prepared by the freeze drying method. By controlling the rate of cooling and concentration, we have produced both fibrous and sheet

  17. Influence of spark plasma sintering and baghdadite powder on mechanical properties of hydroxyapatite

    NARCIS (Netherlands)

    Khandan, A.; Karamian, E.; Mehdikhani-Nahrkhalaji, M.; Mirmohammadi, H.; Farzadi, A.; Ozada, N.; Heidarshenas, B.; Zamani, K.

    2015-01-01

    Since hydroxyapatite-based materials have similar composition and crystallinity as natural calcified tissues, can be used for bone/tissue engineering. In the present study a novel nanocomposite based on bioceramics such as Natural Hydroxyapatite (NHA) and Baghdadite (BAG), was sintered by spark

  18. Hydroxyapatite coating on stainless steel by biomimetic method

    International Nuclear Information System (INIS)

    Dias, V.M.; Maia Filho, A.L.M.; Silva, G.; Sousa, E. de; Cardoso, K.R.

    2010-01-01

    Austenitic stainless steels are widely used in implants due to their high mechanical strength and corrosion, however, are not able to connect to bone tissue and were classified as bioinert. The calcium phosphate ceramics such as hydroxyapatite (HA) are bioactive materials and create strong chemical bonds with bone tissue, but its brittleness and low fracture toughness render its use in conditions of high mechanical stress. The coating of steel with the bioactive ceramics such as HA, combines the properties of interest of both materials, accelerating bone formation around the implant. In this study, austenitic stainless steel samples were coated with apatite using the biomimetic method. The effect of three different surface conditions of steel and the immersion time in the SBF solution on the coating was evaluated. The samples were characterized by SEM, EDS and X-ray diffraction. (author)

  19. Bioactivity of calcium phosphate bioceramic coating fabricated by laser cladding

    Science.gov (United States)

    Zhu, Yizhi; Liu, Qibin; Xu, Peng; Li, Long; Jiang, Haibing; Bai, Yang

    2016-05-01

    There were always strong expectations for suitable biomaterials used for bone regeneration. In this study, to improve the biocompatiblity of titanium alloy, calcium phosphate bioceramic coating was obtained by laser cladding technology. The microstructure, phases, bioactivity, cell differentiation, morphology and resorption lacunae were investigated by optical microscope (OM), x-ray diffraction (XRD), methyl thiazolyl tetrazolium (MTT) assay, tartrate-resistant acid phosphatase (TRAP) staining and scanning electronic microscope (SEM), respectively. The results show that bioceramic coating consists of three layers, which are a substrate, an alloyed layer and a ceramic layer. Bioactive phases of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) were found in ceramic coating. Osteoclast precursors have excellent proliferation on the bioceramic surface. The bioceramics coating could be digested by osteoclasts, which led to the resorption lacunae formed on its surface. It revealed that the gradient bioceramic coating has an excellent bioactivity.

  20. Bioactivity of calcium phosphate bioceramic coating fabricated by laser cladding

    International Nuclear Information System (INIS)

    Zhu, Yizhi; Liu, Qibin; Xu, Peng; Li, Long; Jiang, Haibing; Bai, Yang

    2016-01-01

    There were always strong expectations for suitable biomaterials used for bone regeneration. In this study, to improve the biocompatiblity of titanium alloy, calcium phosphate bioceramic coating was obtained by laser cladding technology. The microstructure, phases, bioactivity, cell differentiation, morphology and resorption lacunae were investigated by optical microscope (OM), x-ray diffraction (XRD), methyl thiazolyl tetrazolium (MTT) assay, tartrate-resistant acid phosphatase (TRAP) staining and scanning electronic microscope (SEM), respectively. The results show that bioceramic coating consists of three layers, which are a substrate, an alloyed layer and a ceramic layer. Bioactive phases of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) were found in ceramic coating. Osteoclast precursors have excellent proliferation on the bioceramic surface. The bioceramics coating could be digested by osteoclasts, which led to the resorption lacunae formed on its surface. It revealed that the gradient bioceramic coating has an excellent bioactivity. (letter)

  1. Bioactive glass 45S5 from diatom biosilica

    Directory of Open Access Journals (Sweden)

    Luqman A. Adams

    2017-12-01

    Full Text Available A major draw-back to large scale production of bioactive glasses is the high cost of the standard silica precursor, usually tetraethyl orthosilicate (TEOS. The current study describes a novel sol–gel preparation of 45S5 bioactive glass using diatom biosilica from cultured cells of the diatom, Aulacoseira granulata as substitute to TEOS. The glass formed was characterized using mechanical tester, scanning electron microscopy (SEM, energy dispersive X-ray analysis (EDX, X-ray diffraction (XRD and Fourier transform infrared (FTIR spectroscopy. Results showed that the glass possessed a compressive strength of 3.75 ± 0.18 and formed carbonated hydroxyapatite (HCA within 7 days in simulated body fluid (SBF, attributable to good surface chemistry. The performance of the glass was compared with that of those formed using TEOS. Diatom biosilica could be a potential economically friendly starting material for large scale fabrication of bioactive glasses.

  2. Tensile properties and microstructural analysis of spheroidized hydroxyapatite-poly (etheretherketone) biocomposites

    International Nuclear Information System (INIS)

    Abu Bakar, M.S.; Cheang, P.; Khor, K.A.

    2003-01-01

    Poly(etheretherketone) or PEEK, is a high performance thermoplastic possessing exceptional mechanical properties, high temperature durability, good chemical and fatigue resistance. These coupled with its ability to withstand sterilization treatment, make it a preferred material for biomedical applications. This study examines the benefit of incorporating hydroxyapatite particulates in poly(etheretherketone) for possible usage as bone analogue materials. Flame spheroidized hydroxyapatite (FSHA) were incorporated into semi-crystalline poly(etheretherketone) polymer through a series of processes comprising melt compounding, granulating and injection molding. Biocomposites with high hydroxyapatite loading of up to 40 vol.% were processed successfully using this technique. Scanning electron microscopy (SEM) revealed fair dispersion and distribution of hydroxyapatite particles within the polymer matrix. The series of composites were characterized in terms of tensile and microhardness properties. Microstructural analysis was also carried out to correlate the structure-property relationship of the composite. The dependency of tensile properties such as modulus, strength and strain to fracture as well as the micro-hardness on the volume percentage of hydroxyapatite were investigated. By varying the amount of hydroxyapatite particles in the composite, a wide range of mechanical properties were obtained. In general, the tensile modulus and microhardness increased, while strength and strain to fracture decreased correspondingly with progressive addition of hydroxyapatite particles. The composite system under investigation also exhibited mechanical properties matching those of human bone. With hydroxyapatite loading beyond 30 vol.%, the modulus were within the bounds of the human cortical bone. Findings from this study suggest that this bioactive composite system have the potential as an alternative implant material for orthopaedic application

  3. Trehalose and Trehalose-based Polymers for Environmentally Benign, Biocompatible and Bioactive Materials

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Shibata

    2008-08-01

    Full Text Available Abstract: Trehalose is a non-reducing disaccharide that is found in many organisms but not in mammals. This sugar plays important roles in cryptobiosis of selaginella mosses, tardigrades (water bears, and other animals which revive with water from a state of suspended animation induced by desiccation. The interesting properties of trehalose are due to its unique symmetrical low-energy structure, wherein two glucose units are bonded face-to-face by 1→1-glucoside links. The Hayashibara Co. Ltd., is credited for developing an inexpensive, environmentally benign and industrial-scale process for the enzymatic conversion of α-1,4-linked polyhexoses to α,α-D-trehalose, which made it easy to explore novel food, industrial, and medicinal uses for trehalose and its derivatives. Trehalosechemistry is a relatively new and emerging field, and polymers of trehalose derivatives appear environmentally benign, biocompatible, and biodegradable. The discriminating properties of trehalose are attributed to its structure, symmetry, solubility, kinetic and thermodynamic stability and versatility. While syntheses of trehalose-based polymer networks can be straightforward, syntheses and characterization of well defined linear polymers with tailored properties using trehalose-based monomers is challenging, and typically involves protection and deprotection of hydroxyl groups to attain desired structural, morphological, biological, and physical and chemical properties in the resulting products. In this review, we will overview known literature on trehalose’s fascinating involvement in cryptobiology; highlight its applications in many fields; and then discuss methods we used to prepare new trehalose-based monomers and polymers and explain their properties.

  4. Bioactive Eunicellin-Based Diterpenoids from the Soft Coral Cladiella krempfi

    Science.gov (United States)

    Tai, Chi-Jen; Su, Jui-Hsin; Huang, Ming-Shyan; Wen, Zhi-Hong; Dai, Chang-Feng; Sheu, Jyh-Horng

    2011-01-01

    Four new eunicellin-based diterpenoids, krempfielins A–D (1–4), along with two known compounds (5 and 6) have been isolated from a soft coral Cladiella krempfi. The structures of the new metabolites were elucidated by extensive spectroscopic analysis and by comparison with spectroscopic data of related known compounds. Compounds 5 and 6 were shown to exhibit cytotoxicity against a limited panel of cancer cell lines. Furthermore, compounds 2, 3, 5 and 6 were shown to exert significant in vitro anti-inflammatory activity against LPS-stimulated RAW264.7 macrophage cells. PMID:22073008

  5. Klymollins T-X, bioactive eunicellin-based diterpenoids from the soft coral Klyxum molle.

    Science.gov (United States)

    Chang, Fang-Yu; Hsu, Fang-Jung; Tai, Chi-Jen; Wei, Wen-Chi; Yang, Ning-Sun; Sheu, Jyh-Horng

    2014-05-22

    Five new eunicellin-based diterpenoids, klymollins T-X (1-5), along with two known compounds (6 and 7) have been isolated from the soft coral Klyxum molle. The structures of these new metabolites were elucidated by extensive spectroscopic analysis and by comparison with related known compounds. Compound 5 was found to exert significant in vitro anti-inflammatory activity against LPS-stimulated RAW264.7 macrophage cells. Furthermore, compounds 4 and 7 were shown to exhibit cytotoxicity against a limited panel of human cancer cell lines.

  6. Klymollins A-H, bioactive eunicellin-based diterpenoids from the formosan soft coral Klyxum molle.

    Science.gov (United States)

    Hsu, Fang-Jung; Chen, Bo-Wei; Wen, Zhi-Hong; Huang, Chiung-Yao; Dai, Chang-Feng; Su, Jui-Hsin; Wu, Yang-Chang; Sheu, Jyh-Horng

    2011-11-28

    Eight new eunicellin-based diterpenoids, klymollins A-H (1-8), were isolated during the chemical investigation of the soft coral Klyxum molle from Taiwan waters. Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of 4 was determined by Mosher's method. Bioassays of the new metabolites showed that compounds 3-8 displayed significant in vitro anti-inflammatory activity by inhibiting the expression of the iNOS protein, and compounds 3, 4, and 6-8 also could effectively reduce the accumulation of COX-2 protein in LPS-stimulated RAW264.7 macrophage cells.

  7. Design of Xylose-Based Semisynthetic Polyurethane Tissue Adhesives with Enhanced Bioactivity Properties.

    Science.gov (United States)

    Balcioglu, Sevgi; Parlakpinar, Hakan; Vardi, Nigar; Denkbas, Emir Baki; Karaaslan, Merve Goksin; Gulgen, Selam; Taslidere, Elif; Koytepe, Suleyman; Ates, Burhan

    2016-02-01

    Developing biocompatible tissue adhesives with high adhesion properties is a highly desired goal of the tissue engineering due to adverse effects of the sutures. Therefore, our work involves synthesis, characterization, adhesion properties, protein adsorption, in vitro biodegradation, in vitro and in vivo biocompatibility properties of xylose-based semisynthetic polyurethane (NPU-PEG-X) bioadhesives. Xylose-based semisynthetic polyurethanes were developed by the reaction among 4,4'-methylenebis(cyclohexyl isocyanate) (MCI), xylose and polyethylene glycol 200 (PEG). Synthesized polyurethanes (PUs) showed good thermal stability and high adhesion strength. The highest values in adhesion strength were measured as 415.0 ± 48.8 and 94.0 ± 2.8 kPa for aluminum substrate and muscle tissue in 15% xylose containing PUs (NPU-PEG-X-15%), respectively. The biodegradation of NPU-PEG-X-15% was also determined as 19.96 ± 1.04% after 8 weeks of incubation. Relative cell viability of xylose containing PU was above 86%. Moreover, 10% xylose containing NPU-PEG-X (NPU-PEG-X-10%) sample has favorable tissue response, and inflammatory reaction between 1 and 6 weeks implantation period. With high adhesiveness and biocompatibility properties, NPU-PEG-X can be used in the medical field as supporting materials for preventing the fluid leakage after abdominal surgery or wound closure.

  8. Weighted similarity-based clustering of chemical structures and bioactivity data in early drug discovery.

    Science.gov (United States)

    Perualila-Tan, Nolen Joy; Shkedy, Ziv; Talloen, Willem; Göhlmann, Hinrich W H; Moerbeke, Marijke Van; Kasim, Adetayo

    2016-08-01

    The modern process of discovering candidate molecules in early drug discovery phase includes a wide range of approaches to extract vital information from the intersection of biology and chemistry. A typical strategy in compound selection involves compound clustering based on chemical similarity to obtain representative chemically diverse compounds (not incorporating potency information). In this paper, we propose an integrative clustering approach that makes use of both biological (compound efficacy) and chemical (structural features) data sources for the purpose of discovering a subset of compounds with aligned structural and biological properties. The datasets are integrated at the similarity level by assigning complementary weights to produce a weighted similarity matrix, serving as a generic input in any clustering algorithm. This new analysis work flow is semi-supervised method since, after the determination of clusters, a secondary analysis is performed wherein it finds differentially expressed genes associated to the derived integrated cluster(s) to further explain the compound-induced biological effects inside the cell. In this paper, datasets from two drug development oncology projects are used to illustrate the usefulness of the weighted similarity-based clustering approach to integrate multi-source high-dimensional information to aid drug discovery. Compounds that are structurally and biologically similar to the reference compounds are discovered using this proposed integrative approach.

  9. Carbonate hydroxyapatite and silicon-substituted carbonate hydroxyapatite

    DEFF Research Database (Denmark)

    Bang, L T; Long, B D; Othman, R

    2014-01-01

    The present study investigates the chemical composition, solubility, and physical and mechanical properties of carbonate hydroxyapatite (CO3Ap) and silicon-substituted carbonate hydroxyapatite (Si-CO3Ap) which have been prepared by a simple precipitation method. X-ray diffraction (XRD), Fourier......(3-)) site and also entered simultaneously into the hydroxyapatite structure. The Si-substituted CO3Ap reduced the powder crystallinity and promoted ion release which resulted in a better solubility compared to that of Si-free CO3Ap. The mean particle size of Si-CO3Ap was much finer than that of CO3Ap...

  10. Optimization of PEG-based extraction of polysaccharides from Dendrobium nobile Lindl. and bioactivity study.

    Science.gov (United States)

    Zhang, Yi; Wang, Hongxin; Wang, Peng; Ma, ChaoYang; He, GuoHua; Rahman, Md Ramim Tanver

    2016-11-01

    Polyethylene glycol (PEG) as a green solvent was employed to extract polysaccharide. The optimal conditions for PEG-based ultrasonic extraction of Dendrobium nobile Lindl. polysaccharide (JCP) were determined by response surface methodology. Under the optimal conditions: extraction temperature of 58.5°C; ultrasound power of 193W, and the concentration of polyethylene glycol-200 (PEG-200) solution of 45%, the highest JCP yield was obtained as 15.23±0.57%, which was close to the predicted yield, 15.57%. UV and FT-IR analysis revealed the general characteristic absorption peaks of both JCP with water extraction (JCP w ) and PEG-200 solvent extraction (JCP p ). Thermal analysis of both JCPs was performed with Thermal Gravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC). Antioxidant activities of two polysaccharides were also compared and no significant difference in vitro was obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Bioactive composite for keratoprosthesis skirt.

    Science.gov (United States)

    Laattala, Kaisa; Huhtinen, Reeta; Puska, Mervi; Arstila, Hanna; Hupa, Leena; Kellomäki, Minna; Vallittu, Pekka K

    2011-11-01

    In this study, the fabrication and properties of a synthetic keratoprosthesis skirt for use in osteo-odonto-keratoprosthesis (OOKP) surgery are discussed. In the search for a new material concept, bioactive glass and polymethyl methacrylate (PMMA)-based composites were prepared. Three different bioactive glasses (i.e. 45S5, S53P4 and 1-98) and one slowly resorbing glass, FL107, with two different forms (i.e. particles and porous glass structures) were employed in the fabrication of specimens. In in vitro studies, the dissolution behaviour in simulated aqueous humour, compressive properties, and pore formation of the composites were investigated. According to the results, FL107 dissolved very slowly (2.4% of the initial glass content in three weeks); thus, the pore formation of the FL107 composite was also observed to be restricted. The dissolution rates of the bioactive glass-PMMA composites were greater (12%-17%). These faster dissolving bioactive glass particles caused some porosity on the outermost surfaces of the composite. The slight surface porosity was also confirmed by a decrease in compressive properties. During six weeks' in vitro dissolution, the compressive strength of the test specimens containing particles decreased by 22% compared to values in dry conditions (90-107 MPa). These results indicate that the bioactive composites could be stable synthetic candidates for a keratoprosthesis skirt in the treatment of severely damaged or diseased cornea. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Chemical-Gene Interactions from ToxCast Bioactivity Data Expands Universe of Literature Network-Based Associations (SOT)

    Science.gov (United States)

    Characterizing the effects of chemicals in biological systems is often summarized by chemical-gene interactions, which have sparse coverage in the literature. The ToxCast chemical screening program has produced bioactivity data for nearly 2000 chemicals and over 450 gene targets....

  13. Synthesis, crystal structure and bioactivity of manganese complexes with asymmetric chiral Schiff base

    Science.gov (United States)

    Zhang, Enfeng; Wei, Yi; Huang, Fuping; Yu, Qing; Bian, Hedong; Liang, Hong; Lei, Fuhou

    2018-03-01

    A couple of chiral unsymmtrical Schiff base ligands, (1R,2R) (-)chxn (salH) (naftalH) and (1S,2S) (-)chxn (salH) (naftalH) had been synthesized by the condensation of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with two isomers of (1R,2R)-trans-1,2-cyclohexanediamin and (1S,2S)-trans-1,2-cyclohexanediamin, respectively. At the same time, two manganese complexes have been synthesized and fully characterized by FT-IR spectrum, elemental analyses, single crystal X-ray diffraction. The interaction of the two Mn (III) complexes with bovine serum albumin (BSA) was investigated by spectroscopic techniques. The result reveals that the complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism. The binding constant and binding mode has been determined. The secondary structure and the amino acid residues microenvironment of BSA change in the presence of these complexes. SOD-like activity and ABTS free radical scavenging ability were also studied. The antioxidant capacity of the compounds showed that the complexes and their corresponding BSA adducts showed some SOD activity. The results of ABTS free radical scavenging showed that the activity of the BSA adduct was more obvious than that of the complex.

  14. Characterization of hydroxyapatite substituted with silicon; Caracterizacao de hiroxiapatita substituida com silicio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, H.M. da; Soares, G.A., E-mail: helena@metalmat.ufrj.b [Universidade Federal do Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao em Engenharia. Lab. de Biomateriais para Engenharia Ossea; Mateescu, M.; Anselme, K. [Universite de Haute-Alsace (UHA/IS2M), Mulhouse (France). Inst. de Science des Materiaux; Palard, M.; Champion, E. [Universite de Limoges (France). Fac. des Sciences et Techniques

    2009-07-01

    Incorporation of silicon (Si) ions into hydroxyapatite structure (HA) influences on physical, chemical and physiological properties. Some studies reported the improved bioactivity Si substitution, and it also accelerates the biomineralization process. The main objective of this work is to characterize stoichiometric hydroxyapatite and hydroxyapatite substituted with 1.13% in weight of Si (SiHA) using a wet precipitation method followed by a heat treatment. SEM/EDS, AFM, DRX and FTIR analyses were used to characterize the samples. EDS and FTIR results confirmed the presence of Si. Silicon induces small changes on crystal structure of HA, not detected on X-ray diffraction patterns of sintered tablets of SiHA and HA. No secondary phases were observed, that indicates the Si had entered the HA lattice. (author)

  15. Bioactive Potential of Marine Macroalgae from the Central Red Sea (Saudi Arabia) Assessed by High-Throughput Imaging-Based Phenotypic Profiling

    KAUST Repository

    Kremb, Stephan Georg

    2017-03-20

    Marine algae represent an important source of novel natural products. While their bioactive potential has been studied to some extent, limited information is available on marine algae from the Red Sea. This study aimed at the broad discovery of new bioactivities from a collection of twelve macroalgal species from the Central Red Sea. We used imaging-based High-Content Screening (HCS) with a diverse spectrum of cellular markers for detailed cytological profiling of fractionated algal extracts. The cytological profiles for 3 out of 60 algal fractions clustered closely to reference inhibitors and showed strong inhibitory activities on the HIV-1 reverse transcriptase in a single-enzyme biochemical assay, validating the suggested biological target. Subsequent chemical profiling of the active fractions of two brown algal species by ultra-high resolution mass spectrometry (FT-ICR-MS) revealed possible candidate molecules. A database query of these molecules led us to groups of compounds with structural similarities, which are suggested to be responsible for the observed activity. Our work demonstrates the versatility and power of cytological profiling for the bioprospecting of unknown biological resources and highlights Red Sea algae as a source of bioactives that may serve as a starting point for further studies.

  16. Bioactive Potential of Marine Macroalgae from the Central Red Sea (Saudi Arabia) Assessed by High-Throughput Imaging-Based Phenotypic Profiling

    KAUST Repository

    Kremb, Stephan Georg; Mü ller, Constanze; Schmitt-Kopplin, Philippe; Voolstra, Christian R.

    2017-01-01

    Marine algae represent an important source of novel natural products. While their bioactive potential has been studied to some extent, limited information is available on marine algae from the Red Sea. This study aimed at the broad discovery of new bioactivities from a collection of twelve macroalgal species from the Central Red Sea. We used imaging-based High-Content Screening (HCS) with a diverse spectrum of cellular markers for detailed cytological profiling of fractionated algal extracts. The cytological profiles for 3 out of 60 algal fractions clustered closely to reference inhibitors and showed strong inhibitory activities on the HIV-1 reverse transcriptase in a single-enzyme biochemical assay, validating the suggested biological target. Subsequent chemical profiling of the active fractions of two brown algal species by ultra-high resolution mass spectrometry (FT-ICR-MS) revealed possible candidate molecules. A database query of these molecules led us to groups of compounds with structural similarities, which are suggested to be responsible for the observed activity. Our work demonstrates the versatility and power of cytological profiling for the bioprospecting of unknown biological resources and highlights Red Sea algae as a source of bioactives that may serve as a starting point for further studies.

  17. In vitro bioactivity, tribological property, and antibacterial ability of Ca-Si-based coatings doped with cu particles in-situ fabricated by laser cladding

    Science.gov (United States)

    Hou, Baoping; Yang, Zhao; Yang, Yuling; Zhang, Erlin; Qin, Gaowu

    2018-03-01

    The present study aimed to in-situ fabricate Ca-Si-based coatings doped with copper particles (Cu-CS coatings) to enhance in vitro bioactivity, tribological property, and antibacterial ability of Ti-6Al-4V alloy. The effects of copper addition on the multiple properties were evaluated. Our results showed that Ca2SiO4, CaTiO3, and Cu2O were in-situ fabricated after laser processing. The Cu-CS coatings exhibited an excellent wear resistance and enhanced wettability. Regarding the in vitro bioactivity, after soaking in simulated body fluid, Cu-CS coatings developed an apatite surface layer that was reduced in the coatings with higher weight percent Cu addition. The Cu-CS coatings enhanced the inhibitory action against E. coli strains, especially for the coating with a higher concentration of Cu in it. Hence, the synthesized Cu-CS coatings present excellent tribological properties, enhanced bioactivity, and antibacterial property, and, therefore, would be used to modify the surface properties of Ti-6Al-4V implants for bone tissue engineering applications.

  18. Dual-target screening of bioactive components from traditional Chinese medicines by hollow fiber-based ligand fishing combined with liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Chen, Liang; Wang, Xin; Liu, Youping; Di, Xin

    2017-09-05

    A novel strategy was developed for dual-target screening of bioactive components from traditional Chinese medicines (TCMs). This strategy was based on the use of low-cost microporous hollow fibers filled with target enzymes as baits to "fish out" the ligands in TCM extracts, followed by identification of the ligands dissociated from the target-ligand complexes by liquid chromatography-mass spectrometry. Ganjiang Huangqin Huanglian Renshen Decoction (GHHRD), a classical TCM prescription for diabetes treatment, was chosen as a model sample to evaluate the feasibility of the proposed strategy. Three bioactive components were successfully screened out from GHHRD. Coptisine was identified as the ligand of α-glucosidase and baicalin as the ligand of angiotensin-converting enzyme (ACE). Berberine was found to be a dual inhibitor of α-glucosidase and ACE. The results were further verified by enzyme inhibitory assay and molecular docking simulation. The study suggested that our developed strategy would be a powerful tool for screening bioactive components from multi-component and multi-target TCMs. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Implantation of silicon dioxide-based nanocrystalline hydroxyapatite and pure phase beta-tricalciumphosphate bone substitute granules in caprine muscle tissue does not induce new bone formation

    Directory of Open Access Journals (Sweden)

    Ghanaati Shahram

    2013-01-01

    Full Text Available Abstract Background Osteoinductive bone substitutes are defined by their ability to induce new bone formation even at heterotopic implantation sites. The present study was designed to analyze the potential osteoinductivity of two different bone substitute materials in caprine muscle tissue. Materials and methods One gram each of either a porous beta-tricalcium phosphate (β-TCP or an hydroxyapatite/silicon dioxide (HA/SiO2-based nanocrystalline bone substitute material was implanted in several muscle pouches of goats. The biomaterials were explanted at 29, 91 and 181 days after implantation. Conventional histology and special histochemical stains were performed to detect osteoblast precursor cells as well as mineralized and unmineralized bone matrix. Results Both materials underwent cellular degradation in which tartrate-resistant acid phosphatase (TRAP-positive osteoclast-like cells and TRAP-negative multinucleated giant cells were involved. The ß-TCP was completely resorbed within the observation period, whereas some granules of the HA-groups were still detectable after 180 days. Neither osteoblasts, osteoblast precursor cells nor extracellular bone matrix were found within the implantation bed of any of the analyzed biomaterials at any of the observed time points. Conclusions This study showed that ß-TCP underwent a faster degradation than the HA-based material. The lack of osteoinductivity for both materials might be due to their granular shape, as osteoinductivity in goat muscle has been mainly attributed to cylindrical or disc-shaped bone substitute materials. This hypothesis however requires further investigation to systematically analyze various materials with comparable characteristics in the same experimental setting.

  20. Use of agroindustrial waste in the preparation of nanocomposites based on bacterial cellulose and hydroxyapatite; Utilizacao de residuos agroindustriais na elaboracao de bionanocompositos baseados em celulose bacteriana e hidroxiapatita

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Eden B.; Chagas, Bruna S. das; Feitosa, Judith P.A. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Andrade, Fabia K.; Borges, Maria F.; Muniz, Celli R.; Souza Filho, Men de Sa M.; Rosa, Morsyleide F., E-mail: morsyleide.rosa@embrapa.br [Embrapa Agroindustria Tropical, Fortaleza, CE (Brazil); Brigida, Ana I. [Embrapa Agroindustria de Alimentos, Barra de Guaratiba, Rio de Janeiro, RJ (Brazil); Morais, Joao P.S. [Embrapa Algodao, Campina Grande, PB (Brazil)

    2015-07-01

    Environmental issues have supported the interest in renewable sources and agroindustrial residues became a significant resource for the production of new materials. The present work presents the use of agroindustrial residues to obtain bacterial cellulose (BC) for further elaboration of nanocomposites with hydroxyapatite (HA). The production of BC membranes occurred in Hestrin & Schramm medium, cashew juice and sisal liquid waste cultivated under static conditions. After the incubation period, the BC membranes were purified and nanocomposites prepared by successive immersion of the purified membranes in solutions of Calcium Chloride (CaCl{sub 2}), and Sodium Phosphate (Na{sub 2}HPO{sub 4}), followed by drying and subsequent characterization. The materials obtained were characterized by Thermogravimetric Analysis (TGA) and X-ray Diffraction (XRD). Additionally, in vitro tests were performed for nanocomposites. The results showed the production of cellulose from the three substrates studied, without the need for further supplementation or pH change. In all characterizations, structure and typical behavior of bacterial cellulose were found. The composites showed bioactivity and the adsorption capacity of proteins, which lead to potential biocompatibility of these materials. (author)

  1. A glass fiber-reinforced composite - bioactive glass cranioplasty implant: A case study of an early development stage implant removed due to a late infection.

    Science.gov (United States)

    Posti, Jussi P; Piitulainen, Jaakko M; Hupa, Leena; Fagerlund, Susanne; Frantzén, Janek; Aitasalo, Kalle M J; Vuorinen, Ville; Serlo, Willy; Syrjänen, Stina; Vallittu, Pekka K

    2015-03-01

    This case study describes the properties of an early development stage bioactive glass containing fiber-reinforced composite calvarial implant with histology that has been in function for two years and three months. The patient is a 33-year old woman with a history of substance abuse, who sustained a severe traumatic brain injury later unsuccessfully treated with an autologous bone flap and a custom-made porous polyethylene implant. She was thereafter treated with developmental stage glass fiber-reinforced composite - bioactive glass implant. After two years and three months, the implant was removed due to an implant site infection. The implant was analyzed histologically, mechanically, and in terms of chemistry and dissolution of bioactive glass. Mechanical integrity of the load bearing fiber-reinforced composite part of the implant was not affected by the in vivo period. Bioactive glass particles demonstrated surface layers of hydroxyapatite like mineral and dissolution, and related increase of pH was considerably less after two and three months period than that for fresh bioactive glass. There was a difference in the histology of the tissues inside the implant areas near to the margin of the implant that absorbed blood during implant installation surgery, showed fibrous tissue with blood vessels, osteoblasts, collagenous fibers with osteoid formation, and tiny clusters of more mature hard tissue. In the center of the implant, where there was less absorbed blood, only fibrous tissue was observed. This finding is in line with the combined positron emission tomography - computed tomography examination with (18F)-fluoride marker, which demonstrated activity of the mineralizing bone by osteoblasts especially at the area near to the margin of the implant 10 months after implantation. Based on these promising reactions found in the bioactive glass containing fiber-reinforced composite implant that has been implanted for two years and three months, calvarial

  2. The drug release study of ceftriaxone from porous hydroxyapatite scaffolds.

    Science.gov (United States)

    Al-Sokanee, Zeki N; Toabi, Abedl Amer H; Al-Assadi, Mohammed J; Alassadi, Erfan A S

    2009-01-01

    Hydroxyapatite (HAP) is an important biomedical material that is used for grafting osseous defects. It has an excellent bioactivity and biocompatibility properties. To isolate hydroxyapatite, pieces of cleaned cattle's bone were heated at different temperature range from 400 degrees C up to 1,200 degrees C. A reasonable yield of 60.32% w/w HAP was obtained at temperature range from 1,000 degrees C to 1,200 degrees C. Fourier transform infrared spectra and the thermogravimetric measurement showed a clear removal of organic at 600 degrees C as well as an excellent isolation of HAP from the bones which was achieved at 1,000-1,200 degrees C. This was also confirmed from X-ray diffraction of bone sample heated at 1,200 degrees C. The concentration ions were found to be sodium, potassium, lithium, zinc, copper, iron, calcium, magnesium, and phosphate present in bones within the acceptable limits for its role in the bioactivity property of HAP. Glucose powder was used as a porosifier. Glucose was novel and excellent as porogen where it was completely removed by heating, giving an efficient porosity in the used scaffolds. The results exhibited that the ceftriaxone drug release was increased with increasing the porosity. It was found that a faster, higher, and more regular drug release was obtained from the scaffold with a porosity of 10%.

  3. Biomimetic scaffolds based on hydroxyapatite nanorod/poly(D,L) lactic acid with their corresponding apatite-forming capability and biocompatibility for bone-tissue engineering.

    Science.gov (United States)

    Nga, Nguyen Kim; Hoai, Tran Thanh; Viet, Pham Hung

    2015-04-01

    This study presents a facile synthesis of biomimetic hydroxyapatite nanorod/poly(D,L) lactic acid (HAp/PDLLA) scaffolds with the use of solvent casting combined with a salt-leaching technique for bone-tissue engineering. Field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy were used to observe the morphologies, pore structures of synthesized scaffolds, interactions between hydroxyapatite nanorods and poly(D,L) lactic acid, as well as the compositions of the scaffolds, respectively. Porosity of the scaffolds was determined using the liquid substitution method. Moreover, the apatite-forming capability of the scaffolds was evaluated through simulated body fluid (SBF) incubation tests, whereas the viability, attachment, and distribution of human osteoblast cells (MG 63 cell line) on the scaffolds were determined through alamarBlue assay and confocal laser microscopy after nuclear staining with 4',6-diamidino-2-phenylindole and actin filaments of a cytoskeleton with Oregon Green 488 phalloidin. Results showed that hydroxyapatite nanorod/poly(D,L) lactic acid scaffolds that mimic the structure of natural bone were successfully produced. These scaffolds possessed macropore networks with high porosity (80-84%) and mean pore sizes ranging 117-183 μm. These scaffolds demonstrated excellent apatite-forming capabilities. The rapid formation of bone-like apatites with flower-like morphology was observed after 7 days of incubation in SBFs. The scaffolds that had a high percentage (30 wt.%) of hydroxyapatite demonstrated better cell adhesion, proliferation, and distribution than those with low percentages of hydroxyapatite as the days of culture increased. This work presented an efficient route for developing biomimetic composite scaffolds, which have potential applications in bone-tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Designed Synthesis of Nanostructured Magnetic Hydroxyapatite Based Drug Nanocarrier for Anti-Cancer Drug Delivery toward the Treatment of Human Epidermoid Carcinoma

    Directory of Open Access Journals (Sweden)

    Bharath Govindan

    2017-06-01

    Full Text Available Superparamagnetic Fe3O4 nanoparticles on hydroxyapatite nanorod based nanostructures (Fe3O4/HAp were synthesized using hydrothermal techniques at 180 °C for 12 h and were used as drug delivery nanocarriers for cancer cell therapeutic applications. The synthesized Fe3O4/HAp nanocomposites were characterized by X-ray diffraction analysis (XRD, Field emission scanning electron microscopy (FESEM, Fourier transform infrared spectroscopy (FTIR, Brunauer-Emmett-Teller (BET-analysis, and vibrating sample magnetometry (VSM. The morphologies of the Fe3O4/HAp nanocomposites show 15 nm Fe3O4 nanoparticles dispersed in the form of rods. The BET result shows that the synthesized samples have a high specific surface area of 80 m2 g−1 with mesoporous structures. Magnetic measurements revealed that the sample has high saturation magnetization of 18 emu/g with low coercivity. The Fe3O4/HAp nanocomposites had a large specific surface area (SSA, high mesoporous volume, and good magnetic property, which made it a suitable nanocarrier for targeted drug delivery systems. The chemotherapeutic agent, andrographolide, was used to investigate the drug delivery behavior of the Fe3O4/HAp nanocomposites. The human epidermoid skin cancer cells (A431 were used as the model targeting cell lines by treating with andrographolide loaded Fe3O4/HAp nanosystems and were further evaluated for their antiproliferative activities and the induction of apoptosis. Also, the present nanocomposite shows better biocompatibility, therefore it can be used as suitable drug vehicle for cancer therapy applications.

  5. Facile fabrication of poly(L-lactic acid) microsphere-incorporated calcium alginate/hydroxyapatite porous scaffolds based on Pickering emulsion templates.

    Science.gov (United States)

    Hu, Yang; Ma, Shanshan; Yang, Zhuohong; Zhou, Wuyi; Du, Zhengshan; Huang, Jian; Yi, Huan; Wang, Chaoyang

    2016-04-01

    In this study, we develop a facile one-pot approach to the fabrication of poly(L-lactic acid) (PLLA) microsphere-incorporated calcium alginate (ALG-Ca)/hydroxyapatite (HAp) porous scaffolds based on HAp nanoparticle-stabilized oil-in-water Pickering emulsion templates, which contain alginate in the aqueous phase and PLLA in the oil phase. The emulsion aqueous phase is solidified by in situ gelation of alginate with Ca(2+) released from HAp by decreasing pH with slow hydrolysis of D-gluconic acid δ-lactone (GDL) to produce emulsion droplet-incorporated gels, followed by freeze-drying to form porous scaffolds containing microspheres. The pore structure of porous scaffolds can be adjusted by varying the HAp or GDL concentration. The compressive tests show that the increase of HAp or GDL concentration is beneficial to improve the compressive property of porous scaffolds, while the excessive HAp can lead to the decrease in compressive property. Moreover, the swelling behavior studies display that the swelling ratios of porous scaffolds reduce with increasing HAp or GDL concentration. Furthermore, hydrophobic drug ibuprofen (IBU) and hydrophilic drug bovine serum albumin (BSA) are loaded into the microspheres and scaffold matrix, respectively. In vitro drug release results indicate that BSA has a rapid release while IBU has a sustained release in the dual drug-loaded scaffolds. In vitro cell culture experiments verify that mouse bone mesenchymal stem cells can proliferate on the porous scaffolds well, indicating the good biocompatibility of porous scaffolds. All these results demonstrate that the PLLA microsphere-incorporated ALG-Ca/HAp porous scaffolds have a promising potential for tissue engineering and drug delivery applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. MRI of orbital hydroxyapatite implants

    International Nuclear Information System (INIS)

    Flanders, A.E.; De Potter P.; Rao, V.M.; Tom, B.M.; Shields, C.L.; Shields, J.A.

    1996-01-01

    Our aim was to use MRI for the postsurgical assessment of a new form of integrated orbital implant composed of a porous calcium phosphate hydroxyapatite substrate. We studied ten patients 24-74 years of age who underwent enucleation and implantation of a hydroxyapatite ball; 5-13 months after surgery, each patient was examined by spin-echo MRI, with fat suppression and gadolinium enhancement. Fibrovascular ingrowth was demonstrated in all ten patients as areas of enhancement at the periphery of the hydroxyapatite sphere that extended to the center to a variable degree. The radiologist should aware of the MRI appearances of the coralline hydroxyapatite orbital implant since it is now widely used following enucleation. MRI is a useful means to determine successful incorporation of the substrate into the orbital tissues. The normal pattern of contrast enhancement should not be mistaken for recurrent tumor or infection. (orig.)

  7. Synthesis of nanocrystalline fluorinated hydroxyapatite

    Indian Academy of Sciences (India)

    Fluorinated hydroxyapatite; nanocrystalline; microwave synthesis; dissolution. ... HA by the presence of other ions such as carbonate, magnesium, fluoride, etc. ... Fourier transform infrared spectroscopy (FT–IR) and laser Raman spectroscopy.

  8. Introducing the fluorine doped natural hydroxyapatite-titania nanobiocomposite ceramic

    Energy Technology Data Exchange (ETDEWEB)

    Karamian, Ebrahim [Advanced Materials Research Center, Faculty of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of); Abdellahi, Majid, E-mail: M.Abdellahi@Pa.iut.ac.ir [Advanced Materials Research Center, Faculty of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of); Khandan, Amirsalar [Young Researchers and Elite Club, Khomeinishahr Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Abdellah, Sana [Advanced Materials Research Center, Faculty of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of)

    2016-09-15

    In the present research, natural hydroxyapatite (NHA) was synthesized from bovine bones and then fluorine was doped into the NHA matrix to produce fluorine doped NHA (FNHA; natural fluor-hydroxyapatite) in optimum conditions. At the end an FNHA-TiO{sub 2} nanobiocomposite ceramic with excellent biocompatibility and good chemical stability was synthesized through a mechanochemical route and a subsequent two step sintering (TSS) process. Thermal gravimetric analysis (TGA), Differential scanning calorimetry (DSC), X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), inductive coupled plasma (ICP), and energy-dispersive X-ray spectroscopy (EDX) were used as the means for gathering and analysis of the results. According to the obtained results, TiO{sub 2} can prevent early decomposition of FNHA by the formation of the CaTiO{sub 3} phases and hence strengthen the interactions between the apatite particles which results in the increase of the mechanical properties. Besides, TiO{sub 2} provides more Si−OH nucleation sites for the formation of the apatite layers and hence more bioactivity. - Highlights: • This work begins with preparing natural hydroxyapatite from bovine bones via a simple method. • With increasing the TiO{sub 2} content reinforced in FNHA matrix, the compaction increases. • TiO{sub 2} can prevent early decomposition of FNHA by the formation of CaTiO{sub 3} phase. • TiO{sub 2} can strengthen the interactions between the apatite particles and increase of compaction. • With increasing TiO{sub 2} content, the Si−OH nucleation sites increases lead to more bioactivity.

  9. Osseointegration properties of titanium dental implants modified with a nanostructured coating based on ordered porous silica and bioactive glass nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Covarrubias, Cristian, E-mail: ccovarrubias@odontologia.uchile.cl [Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago (Chile); Mattmann, Matías [Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago (Chile); Von Marttens, Alfredo [Department of Prosthesis, Faculty of Dentistry, University of Chile, Santiago (Chile); Caviedes, Pablo; Arriagada, Cristián [Laboratory of Cell Therapy, ICBM, Faculty of Medicine, University of Chile (Chile); Valenzuela, Francisco [Laboratory of Nanobiomaterials, Institute for Research in Dental Sciences, Faculty of Dentistry, University of Chile, Santiago (Chile); Rodríguez, Juan Pablo [Laboratory of Cell Biology, INTA, University of Chile, Santiago (Chile); Corral, Camila [Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Santiago (Chile)

    2016-02-15

    Graphical abstract: - Highlights: • The fabrication of a coating for osseointegration of titanium implant is presented. • The coating consists of nanoporous silica loaded with bioactive glass nanoparticles. • Coating accelerates the in vitro formation of apatite in simulated body fluid. • Coating promotes the osteogenic differentiation of stem cells. • Coating accelerates the formation of bone tissue in the periphery of the implant. - Abstract: The fabrication of a nanoporous silica coating loaded with bioactive glass nanoparticles (nBG/NSC) on titanium dental implant surface and its in vitro and in vivo evaluation is presented. The coating was produced by a combined sol–gel and evaporation induced self-assembly process. In vitro bioactivity was assessed in simulated body fluid (SBF) and investigating the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). A rat tibial model was employed to analyze the bone response to nBG/NSC-modified titanium implant surface in vivo. The nBG/NSC coating was confirmed at nano level to be constituted by a highly ordered nanoporous silica structure. The coating nanotopography in conjunction with the bioactivity of the BG particles accelerate the in vitro apatite formation and promote the osteogenic differentiation of hBMSCs in absence of osteogenic supplements. These properties accelerate the formation of bone tissue in the periphery of the implant after 3 weeks of implantation. Backscattered scanning electron microscopy images revealed the presence of gaps and soft tissue in the unmodified implant after 6 weeks, whereas the nBG/NSC-modified implant showed mature bone in intimate contact with the implant surface. The nBG/NSC coating appears promising for accelerating the osseointegration of dental implants.

  10. Osseointegration properties of titanium dental implants modified with a nanostructured coating based on ordered porous silica and bioactive glass nanoparticles

    International Nuclear Information System (INIS)

    Covarrubias, Cristian; Mattmann, Matías; Von Marttens, Alfredo; Caviedes, Pablo; Arriagada, Cristián; Valenzuela, Francisco; Rodríguez, Juan Pablo; Corral, Camila

    2016-01-01

    Graphical abstract: - Highlights: • The fabrication of a coating for osseointegration of titanium implant is presented. • The coating consists of nanoporous silica loaded with bioactive glass nanoparticles. • Coating accelerates the in vitro formation of apatite in simulated body fluid. • Coating promotes the osteogenic differentiation of stem cells. • Coating accelerates the formation of bone tissue in the periphery of the implant. - Abstract: The fabrication of a nanoporous silica coating loaded with bioactive glass nanoparticles (nBG/NSC) on titanium dental implant surface and its in vitro and in vivo evaluation is presented. The coating was produced by a combined sol–gel and evaporation induced self-assembly process. In vitro bioactivity was assessed in simulated body fluid (SBF) and investigating the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). A rat tibial model was employed to analyze the bone response to nBG/NSC-modified titanium implant surface in vivo. The nBG/NSC coating was confirmed at nano level to be constituted by a highly ordered nanoporous silica structure. The coating nanotopography in conjunction with the bioactivity of the BG particles accelerate the in vitro apatite formation and promote the osteogenic differentiation of hBMSCs in absence of osteogenic supplements. These properties accelerate the formation of bone tissue in the periphery of the implant after 3 weeks of implantation. Backscattered scanning electron microscopy images revealed the presence of gaps and soft tissue in the unmodified implant after 6 weeks, whereas the nBG/NSC-modified implant showed mature bone in intimate contact with the implant surface. The nBG/NSC coating appears promising for accelerating the osseointegration of dental implants.

  11. Osseointegration properties of titanium dental implants modified with a nanostructured coating based on ordered porous silica and bioactive glass nanoparticles

    Science.gov (United States)

    Covarrubias, Cristian; Mattmann, Matías; Von Marttens, Alfredo; Caviedes, Pablo; Arriagada, Cristián; Valenzuela, Francisco; Rodríguez, Juan Pablo; Corral, Camila

    2016-02-01

    The fabrication of a nanoporous silica coating loaded with bioactive glass nanoparticles (nBG/NSC) on titanium dental implant surface and its in vitro and in vivo evaluation is presented. The coating was produced by a combined sol-gel and evaporation induced self-assembly process. In vitro bioactivity was assessed in simulated body fluid (SBF) and investigating the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). A rat tibial model was employed to analyze the bone response to nBG/NSC-modified titanium implant surface in vivo. The nBG/NSC coating was confirmed at nano level to be constituted by a highly ordered nanoporous silica structure. The coating nanotopography in conjunction with the bioactivity of the BG particles accelerate the in vitro apatite formation and promote the osteogenic differentiation of hBMSCs in absence of osteogenic supplements. These properties accelerate the formation of bone tissue in the periphery of the implant after 3 weeks of implantation. Backscattered scanning electron microscopy images revealed the presence of gaps and soft tissue in the unmodified implant after 6 weeks, whereas the nBG/NSC-modified implant showed mature bone in intimate contact with the implant surface. The nBG/NSC coating appears promising for accelerating the osseointegration of dental implants.

  12. Integrated HPTLC-based Methodology for the Tracing of Bioactive Compounds in Herbal Extracts Employing Multivariate Chemometrics. A Case Study on Morus alba.

    Science.gov (United States)

    Chaita, Eliza; Gikas, Evagelos; Aligiannis, Nektarios

    2017-03-01

    In drug discovery, bioassay-guided isolation is a well-established procedure, and still the basic approach for the discovery of natural products with desired biological properties. However, in these procedures, the most laborious and time-consuming step is the isolation of the bioactive constituents. A prior identification of the compounds that contribute to the demonstrated activity of the fractions would enable the selection of proper chromatographic techniques and lead to targeted isolation. The development of an integrated HPTLC-based methodology for the rapid tracing of the bioactive compounds during bioassay-guided processes, using multivariate statistics. Materials and Methods - The methanol extract of Morus alba was fractionated employing CPC. Subsequently, fractions were assayed for tyrosinase inhibition and analyzed with HPTLC. PLS-R algorithm was performed in order to correlate the analytical data with the biological response of the fractions and identify the compounds with the highest contribution. Two methodologies were developed for the generation of the dataset; one based on manual peak picking and the second based on chromatogram binning. Results and Discussion - Both methodologies afforded comparable results and were able to trace the bioactive constituents (e.g. oxyresveratrol, trans-dihydromorin, 2,4,3'-trihydroxydihydrostilbene). The suggested compounds were compared in terms of R f values and UV spectra with compounds isolated from M. alba using typical bioassay-guided process. Chemometric tools supported the development of a novel HPTLC-based methodology for the tracing of tyrosinase inhibitors in M. alba extract. All steps of the experimental procedure implemented techniques that afford essential key elements for application in high-throughput screening procedures for drug discovery purposes. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  13. In vitro mechanical integrity of hydroxyapatite coated magnesium alloy

    International Nuclear Information System (INIS)

    Kannan, M Bobby; Orr, Lynnley

    2011-01-01

    The mechanical integrity of resorbable implants during service, especially in load bearing orthopaedic applications, is critical. The high degradation rate of resorbable magnesium and magnesium-based implants in body fluid may potentially cause premature in-service failure. In this study, a magnesium alloy (AZ91) was potentiostatically coated with hydroxyapatite at different cathodic voltages in an attempt to enhance the mechanical integrity. The mechanical integrity of the uncoated and hydroxyapatite coated alloys was evaluated after in vitro testing of the coated samples in simulated body fluid (SBF). The uncoated alloy showed 40% loss in the mechanical strength after five days exposure to SBF. However, the hydroxyapatite coated alloy exposed to SBF showed 20% improvement in the mechanical strength as compared to that of the uncoated alloy. The alloy coated potentiostatically at -2 V performed better than the -3 V coated alloy. The cross-sectional analysis of the coatings revealed relatively uniform coating thickness for the -2 V coated alloy, whereas the -3 V coated alloy exhibited areas of uneven coating. This can be attributed to the increase in hydrogen evolution on the alloy during -3 V coating as compared to -2 V coating. The scanning electron micrographs of the in vitro tested alloy revealed that hydroxyapatite coating significantly reduced the localized corrosion of the alloy, which is critical for better in-service mechanical integrity. Thus, the study suggests that the in vitro mechanical integrity of resorbable magnesium-based alloy can be improved by potentiostatic hydroxyapatite coating.

  14. In vitro mechanical integrity of hydroxyapatite coated magnesium alloy.

    Science.gov (United States)

    Kannan, M Bobby; Orr, Lynnley

    2011-08-01

    The mechanical integrity of resorbable implants during service, especially in load bearing orthopaedic applications, is critical. The high degradation rate of resorbable magnesium and magnesium-based implants in body fluid may potentially cause premature in-service failure. In this study, a magnesium alloy (AZ91) was potentiostatically coated with hydroxyapatite at different cathodic voltages in an attempt to enhance the mechanical integrity. The mechanical integrity of the uncoated and hydroxyapatite coated alloys was evaluated after in vitro testing of the coated samples in simulated body fluid (SBF). The uncoated alloy showed 40% loss in the mechanical strength after five days exposure to SBF. However, the hydroxyapatite coated alloy exposed to SBF showed 20% improvement in the mechanical strength as compared to that of the uncoated alloy. The alloy coated potentiostatically at -2 V performed better than the -3 V coated alloy. The cross-sectional analysis of the coatings revealed relatively uniform coating thickness for the -2 V coated alloy, whereas the -3 V coated alloy exhibited areas of uneven coating. This can be attributed to the increase in hydrogen evolution on the alloy during -3 V coating as compared to -2 V coating. The scanning electron micrographs of the in vitro tested alloy revealed that hydroxyapatite coating significantly reduced the localized corrosion of the alloy, which is critical for better in-service mechanical integrity. Thus, the study suggests that the in vitro mechanical integrity of resorbable magnesium-based alloy can be improved by potentiostatic hydroxyapatite coating. © 2011 IOP Publishing Ltd

  15. In vitro mechanical integrity of hydroxyapatite coated magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, M Bobby; Orr, Lynnley, E-mail: bobby.mathan@jcu.edu.au [Discipline of Chemical Engineering, School of Engineering and Physical Sciences, James Cook University, Townsville, Queensland 4811 (Australia)

    2011-08-15

    The mechanical integrity of resorbable implants during service, especially in load bearing orthopaedic applications, is critical. The high degradation rate of resorbable magnesium and magnesium-based implants in body fluid may potentially cause premature in-service failure. In this study, a magnesium alloy (AZ91) was potentiostatically coated with hydroxyapatite at different cathodic voltages in an attempt to enhance the mechanical integrity. The mechanical integrity of the uncoated and hydroxyapatite coated alloys was evaluated after in vitro testing of the coated samples in simulated body fluid (SBF). The uncoated alloy showed 40% loss in the mechanical strength after five days exposure to SBF. However, the hydroxyapatite coated alloy exposed to SBF showed 20% improvement in the mechanical strength as compared to that of the uncoated alloy. The alloy coated potentiostatically at -2 V performed better than the -3 V coated alloy. The cross-sectional analysis of the coatings revealed relatively uniform coating thickness for the -2 V coated alloy, whereas the -3 V coated alloy exhibited areas of uneven coating. This can be attributed to the increase in hydrogen evolution on the alloy during -3 V coating as compared to -2 V coating. The scanning electron micrographs of the in vitro tested alloy revealed that hydroxyapatite coating significantly reduced the localized corrosion of the alloy, which is critical for better in-service mechanical integrity. Thus, the study suggests that the in vitro mechanical integrity of resorbable magnesium-based alloy can be improved by potentiostatic hydroxyapatite coating.

  16. The Effect of the Nanoscale Structure of Nanobioceramics on Their In Vitro Bioactivity and Cell Differentiation Properties

    Directory of Open Access Journals (Sweden)

    Cristian Covarrubias

    2015-01-01

    Full Text Available The effect of the nanoscale structure of bioceramics on their in vitro bioactivity and capacity to osteogenically differentiate stem cell is studied. Nanoparticles of hydroxyapatite (nHA, bioactive glass (nBG, nanoporous bioactive glass (MBG, and nanoporous bioactive glass nanospheres (nMBG are investigated. The nanometric particle size of bioceramics seems to be more determining in controlling the ability to induce bone-like apatite as compared to the nanoporous structure. At short incubation time, nBG also produces a bioactive extracellular medium capable of upregulating key osteogenic markers involved in the development of a mineralizing phenotype in DPSCs. The bioactive properties of nBG are promissory for accelerating the bone regeneration process in tissue engineering applications.

  17. Investigation of bioactivity and cell effects of nano-porous sol–gel derived bioactive glass film

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhijun, E-mail: mokuu@zju.edu.cn [State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640 (China); Ji, Huijiao [College of Life Science, Zhejiang University, Hangzhou, 310028 (China); Hu, Xiaomeng [School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640 (China); Teng, Yu [State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640 (China); Zhao, Guiyun; Mo, Lijuan; Zhao, Xiaoli [College of Life Science, Zhejiang University, Hangzhou, 310028 (China); Chen, Weibo [School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640 (China); Qiu, Jianrong, E-mail: qjr@scut.edu.cn [State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640 (China); Zhang, Ming, E-mail: zhangming201201@126.com [College of Life Science, Zhejiang University, Hangzhou, 310028 (China)

    2013-11-01

    In orthopedic surgery, bioactive glass film coating is extensively studied to improve the synthetic performance of orthopedic implants. A lot of investigations have confirmed that nano-porous structure in bioactive glasses can remarkably improve their bioactivity. Nevertheless, researches on preparation of nano-porous bioactive glasses in the form of film coating and their cell response activities are scarce. Herein, we report the preparation of nano-porous bioactive glass film on commercial glass slide based on a sol–gel technique, together with the evaluation of its in vitro bioactivity through immersion in simulated body fluid and monitoring the precipitation of apatite-like layer. Cell responses of the samples, including attachment, proliferation and osteogenic differentiation, were also investigated using BMSCS (bone marrow derived mesenchymal stem cells) as a model. The results presented here provide some basic information on structural influence of bioactive glass film on the improvement of bioactivity and cellular effects.

  18. Investigation of bioactivity and cell effects of nano-porous sol-gel derived bioactive glass film

    Science.gov (United States)

    Ma, Zhijun; Ji, Huijiao; Hu, Xiaomeng; Teng, Yu; Zhao, Guiyun; Mo, Lijuan; Zhao, Xiaoli; Chen, Weibo; Qiu, Jianrong; Zhang, Ming

    2013-11-01

    In orthopedic surgery, bioactive glass film coating is extensively studied to improve the synthetic performance of orthopedic implants. A lot of investigations have confirmed that nano-porous structure in bioactive glasses can remarkably improve their bioactivity. Nevertheless, researches on preparation of nano-porous bioactive glasses in the form of film coating and their cell response activities are scarce. Herein, we report the preparation of nano-porous bioactive glass film on commercial glass slide based on a sol-gel technique, together with the evaluation of its in vitro bioactivity through immersion in simulated body fluid and monitoring the precipitation of apatite-like layer. Cell responses of the samples, including attachment, proliferation and osteogenic differentiation, were also investigated using BMSCS (bone marrow derived mesenchymal stem cells) as a model. The results presented here provide some basic information on structural influence of bioactive glass film on the improvement of bioactivity and cellular effects.

  19. Characterization and bioactivity of nano-submicro octacalcium phosphate/gelatin composite

    International Nuclear Information System (INIS)

    Miura, Kei-ichiro; Anada, Takahisa; Honda, Yoshitomo; Shiwaku, Yukari; Kawai, Tadashi; Echigo, Seishi; Takahashi, Tetsu; Suzuki, Osamu

    2013-01-01

    The present study was designed to investigate the physicochemical and bioactive properties of a nano-submicro sized octacalcium phosphate (OCP)-dispersed gelatin (Gel) composite (nano-submicro OCP/Gel) used as a bone substitute material in various bone defects. Well-grown, synthesized OCP was mechanically ground from 100 to 300 μm-sieved granules to particles that were approximately 500 nm in size. Then, 50 wt% of the nano-submicro OCP was mixed with porcine skin-derived acid extracted gelatin. The mixture was molded and lyophilized and then subjected to dehydrothermal crosslinking. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy showed that the structure of OCP was retained even after mechanical grinding to a nano-submicro scale level as well as inclusion in the Gel matrix. The bioactivity of nano-submicro OCP/Gel was examined by immersing the composite in simulated body fluid (SBF) for 7 days and by implanting it in rat critical-sized calvaria defects for 8 weeks. The nano-submicro OCP tended to convert to low crystalline hydroxyapatite (HA) in SBF as assessed by XRD. The nano-submicro OCP/Gel exhibited osteoconductivity in vivo, yielding new bone formation that was closely associated with the implanted composite. These results suggest that the nano-submicro OCP/Gel composite exhibits similar osteoconductivity as observed in other OCP-based materials previously reported and could be used as a bone substitute material for repairing various defects in bone.

  20. Characterization and bioactivity of nano-submicro octacalcium phosphate/gelatin composite

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Kei-ichiro [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan); Division of Oral and Maxillofacial Surgery, Tohoku University Graduate School of Dentistry, Sendai (Japan); Anada, Takahisa; Honda, Yoshitomo [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan); Shiwaku, Yukari [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan); Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, Sendai (Japan); Kawai, Tadashi; Echigo, Seishi; Takahashi, Tetsu [Division of Oral and Maxillofacial Surgery, Tohoku University Graduate School of Dentistry, Sendai (Japan); Suzuki, Osamu, E-mail: suzuki-o@m.tohoku.ac.jp [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan)

    2013-10-01

    The present study was designed to investigate the physicochemical and bioactive properties of a nano-submicro sized octacalcium phosphate (OCP)-dispersed gelatin (Gel) composite (nano-submicro OCP/Gel) used as a bone substitute material in various bone defects. Well-grown, synthesized OCP was mechanically ground from 100 to 300 μm-sieved granules to particles that were approximately 500 nm in size. Then, 50 wt% of the nano-submicro OCP was mixed with porcine skin-derived acid extracted gelatin. The mixture was molded and lyophilized and then subjected to dehydrothermal crosslinking. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy showed that the structure of OCP was retained even after mechanical grinding to a nano-submicro scale level as well as inclusion in the Gel matrix. The bioactivity of nano-submicro OCP/Gel was examined by immersing the composite in simulated body fluid (SBF) for 7 days and by implanting it in rat critical-sized calvaria defects for 8 weeks. The nano-submicro OCP tended to convert to low crystalline hydroxyapatite (HA) in SBF as assessed by XRD. The nano-submicro OCP/Gel exhibited osteoconductivity in vivo, yielding new bone formation that was closely associated with the implanted composite. These results suggest that the nano-submicro OCP/Gel composite exhibits similar osteoconductivity as observed in other OCP-based materials previously reported and could be used as a bone substitute material for repairing various defects in bone.

  1. Comparative facile methods for preparing graphene oxide-hydroxyapatite for bone tissue engineering.

    Science.gov (United States)

    Raucci, M G; Giugliano, D; Longo, A; Zeppetelli, S; Carotenuto, G; Ambrosio, L

    2017-08-01

    Motivated by the success of using graphene oxide (GO) as a nanofiller of composites, there is a drive to search for this new kind of carbon material as a bioactive component in ceramic materials. In the present study, biomineralized GO was prepared by two different approaches, represented by in situ sol-gel synthesis and biomimetic treatment. It was found that in the biocomposites obtained by the sol-gel approach, the spindle-like hydroxyapatite nanoparticles, with a diameter of ca. 5 ± 0.37 nm and a length of ca. 70 ± 2.5 nm, were presented randomly and strongly on the surface. The oxygen-containing functional groups, such as hydroxyl and carbonyl, present on the basal plane and edges of the GO sheets, play an important role in anchoring calcium ions, as demonstrated by FT-IR and TEM investigations. A different result was obtained for biocomposites after biomimetic treatment: an amorphous calcium phosphate on GO sheet was observed after 5 days of treatment. These different approaches resulted in a diverse effect on the proliferation and differentiation of osteogenic mesenchymal stem cells. In fact, in biocomposites prepared by the sol-gel approach the expression of an early marker of osteogenic differentiation, ALP, increases with the amount of GO in the first days of cell culture. Meanwhile, biomimetic materials sustain cell viability and proliferation, even if the expression of alkaline phosphatase activity in a basal medium is delayed. These findings may provide new prospects for utilizing GO-based hydroxyapatite biocomposites in bone repair, bone augmentation and coating of biomedical implants and broaden the application of GO sheets in biological areas. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Influence of SrO substitution for CaO on the properties of bioactive glass S53P4.

    Science.gov (United States)

    Massera, Jonathan; Hupa, Leena

    2014-03-01

    Commercial melt-quenched bioactive glasses consist of the oxides of silicon, phosphorus, calcium and sodium. Doping of the glasses with oxides of some other elements is known to affect their capability to support hydroxyapatite formation and thus bone tissue healing but also to modify their high temperature processing parameters. In the present study, the influence of gradual substitution of SrO for CaO on the properties of the bioactive glass S53P4 was studied. Thermal analysis and hot stage microscopy were utilized to measure the thermal properties of the glasses. The in vitro bioactivity and solubility was measured by immersing the glasses in simulated body fluid for 6 h to 1 week. The formation of silica rich and hydroxyapatite layers was assessed from FTIR spectra analysis and SEM images of the glass surface. Increasing substitution of SrO for CaO decreased all characteristic temperatures and led to a slightly stronger glass network. The initial glass dissolution rate increased with SrO content. Hydroxyapatite layer was formed on all glasses but on the SrO containing glasses the layer was thinner and contained also strontium. The results suggest that substituting SrO for CaO in S53P4 glass retards the bioactivity. However, substitution greater than 10 mol% allow for precipitation of a strontium substituted hydroxyapatite layer.

  3. Characterization and inhibitive study of gel-grown hydroxyapatite crystals at physiological temperature

    Science.gov (United States)

    Parekh, Bharat; Joshi, Mihir; Vaidya, Ashok

    2008-04-01

    Hydroxyapatite is very useful for various biomedical applications, due to its chemical similarity with mineralized bone of human. Hydroxyapatite is also responsible for arthropathy (joint disease). In the present study, the growth of hydroxyapatite crystals was carried out by using single-diffusion gel growth technique in silica hydro gel media, at physiological temperature. The growth of hydroxyapatite crystals under slow and controlled environment in gel medium can be simulated in a simple manner to the growth in human body. The crystals, formed in the Liesegang rings, were characterized by powder XRD, FTIR and dielectric study. The diffusion study is also carried out for the hydroxyapatite crystals using the moving boundary model. The inhibitive influence of various Ayurvedic medicinal plant extracts such as Boswellia serrata gum resin , Tribulus terrestris fruits, Rotula aquatica roots, Boerhaavia diffusa roots and Commiphora wightii, on the growth of hydroxyapatite was studied. Roots of R. aquatica and B. diffusa show some inhibition of the hydroxyapatite crystals in vitro. This preclinical study will be helpful to design the therapy for prevention of hydroxyapatite-based ailments.

  4. Influence of Starting Powders on Hydroxyapatite Coatings Fabricated by Room Temperature Spraying Method.

    Science.gov (United States)

    Seo, Dong Seok; Lee, Jong Kook; Hwang, Kyu Hong; Hahn, Byung Dong; Yoon, Seog Young

    2015-08-01

    Three types of raw materials were used for the fabrication of hydroxyapatite coatings by using the room temperature spraying method and their influence on the microstructure and in vitro characteristics were investigated. Starting hydroxyapatite powders for coatings on titanium substrate were prepared by a heat treatment at 1100 °C for 2 h of bovine bone, bone ash, and commercial hydroxyapatite powders. The phase compositions and Ca/P ratios of the three hydroxyapatite coatings were similar to those of the raw materials without decomposition or formation of a new phase. All hydroxyapatite coatings showed a honeycomb structure, but their surface microstructures revealed different features in regards to surface morphology and roughness, based on the staring materials. All coatings consisted of nano-sized grains and had dense microstructure. Inferred from in vitro experiments in pure water, all coatings have a good dissolution-resistance and biostability in water.

  5. Synthesis of mesoporous hydroxyapatite using a modified hard-templating route

    International Nuclear Information System (INIS)

    Xia Zhiguo; Liao Libing; Zhao Senlin

    2009-01-01

    Mesoporous polycrystals of hydroxyapatite-calcium are synthesized via a modified hard-templating route. The structure properties of hydroxyapatite-calcium are characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and N 2 adsorption-desorption isotherms. Wide-angle X-ray diffraction and Fourier transform infrared spectroscopy measurements reveal that the crystalline grains consist of highly crystalline pure hydroxyapatite phases. Transmission electron microscopy results show that rod-like hydroxyapatite-calcium grains with an average diameter of about 100 nm long and about 20 nm wide are uniformly distributed, which are also observed with an average pore size of 2-3 nm. Based on N 2 adsorption-desorption isotherms investigation, the pore size, surface area and pore volume of mesoporous hydroxyapatite-calcium are 2.73 nm, 42.43 m 2 g -1 and 0.12 cm 3 g -1 , respectively.

  6. Gelatin/nano-hydroxyapatite hydrogel scaffold prepared by sol-gel technology as filler to repair bone defects.

    Science.gov (United States)

    Raucci, Maria Grazia; Demitri, Christian; Soriente, Alessandra; Fasolino, Ines; Sannino, Alessandro; Ambrosio, Luigi

    2018-07-01

    This study reports on the development of a scaffold with a gradient of bioactive solid signal embedded in the biodegradable polymer matrix by combining a sol-gel approach and freeze-drying technology. The chemical approach based on the sol-gel transition of calcium phosphates ensures the particles dispersion into the gelatin matrix and a direct control of interaction among COOH gelatin /Ca 2+ ions. Morphological analysis demonstrated that on the basis of the amount of inorganic component and by using specific process conditions, it is possible to control the spatial distribution of nanoparticles around the gelatin helix. In fact, methodology and formulations were able to discriminate between the different hydroxyapatite concentrations and their respective morphology. The good biological response represented by good cell attachment, proliferation and increased levels of alkaline phosphatase as an indicator of osteoblastic differentiation of human mesenchymal stem cells toward the osteogenic lineage, demonstrating the effect of bioactive solid signals on cellular behavior. Furthermore, the inhibition of reactive oxygen species production by composite materials predicted potential anti-inflammatory properties of scaffolds thus confirming their biocompatibility. Indeed, these interesting biological results suggest good potential application of this scaffold as filler to repair bone defects. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2007-2019, 2018. © 2018 Wiley Periodicals, Inc.

  7. Bio-activity of aminosulfonyl ureas in the light of nucleic acid bases and DNA base pair interaction.

    Science.gov (United States)

    Mondal Roy, Sutapa

    2018-08-01

    The quantum chemical descriptors based on density functional theory (DFT) are applied to predict the biological activity (log IC 50 ) of one class of acyl-CoA: cholesterol O-acyltransferase (ACAT) inhibitors, viz. aminosulfonyl ureas. ACAT are very effective agents for reduction of triglyceride and cholesterol levels in human body. Successful two parameter quantitative structure-activity relationship (QSAR) models are developed with a combination of relevant global and local DFT based descriptors for prediction of biological activity of aminosulfonyl ureas. The global descriptors, electron affinity of the ACAT inhibitors (EA) and/or charge transfer (ΔN) between inhibitors and model biosystems (NA bases and DNA base pairs) along with the local group atomic charge on sulfonyl moiety (∑Q Sul ) of the inhibitors reveals more than 90% efficacy of the selected descriptors for predicting the experimental log (IC 50 ) values. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Structural Properties and Antifungal Activity against Candida albicans Biofilm of Different Composite Layers Based on Ag/Zn Doped Hydroxyapatite-Polydimethylsiloxanes

    Directory of Open Access Journals (Sweden)

    Andreea Groza

    2016-04-01

    Full Text Available Modern medicine is still struggling to find new and more effective methods for fighting off viruses, bacteria and fungi. Among the most dangerous and at times life-threatening fungi is Candida albicans. Our work is focused on surface and structural characterization of hydroxyapatite, silver doped hydroxyapatite and zinc doped hydroxyapatite deposited on a titanium substrate previously coated with polydimethylsiloxane (HAp-PDMS, Ag:HAp-PDMS, Zn:HAp-PDMS by different techniques: Scanning Electron Microscopy (SEM, Glow Discharge Optical Emission Spectroscopy (GDOES and Fourier Transform Infrared Spectroscopy (FTIR. The morphological studies revealed that the use of the PDMS polymer as an interlayer improves the quality of the coatings. The structural characterizations of the thin films revealed the basic constituents of both apatitic and PDMS structure. In addition, the GD depth profiles indicated the formation of a composite material as well as the successful embedding of the HAp, Zn:HAp and Ag:HAp into the polymer. On the other hand, in vitro evaluation of the antifungal properties of Ag:HAp-PDMS and Zn:HAp-PDMS demonstrated the fungicidal effects of Ag:HAp-PDMS and the potential antifungal effect of Zn:HAp-PDMS composite layers against C. albicans biofilm. The results acquired in this research complete previous research on the potential use of new complex materials produced by nanotechnology in biomedicine.

  9. Investigating an organ-targeting platform based on hydroxyapatite nanoparticles using a novel in situ method of radioactive ¹²⁵Iodine labeling.

    Science.gov (United States)

    Ignjatović, Nenad; Vranješ Djurić, Sanja; Mitić, Zarko; Janković, Drina; Uskoković, Dragan

    2014-10-01

    In this study, we have investigated the synthesis of nanoparticles of hydroxyapatite (HAp) and hydroxyapatite coated with chitosan (HAp/Ch) and the chitosan-poly-d,l-lactide-co-glycolide polymer blend (HAp/Ch-PLGA) as an organ-targeting system. We have examined and defined the final destination, as well as the dynamics and the pathways of the synthesized particles following intravenous administration in vivo. The XRD, ZP, FT-IR and SEM analyses have confirmed that the hydroxyapatite nanoparticles with d50=72 nm are coated with polymers. Radioactive 125-Iodine ((125)I), a low energy gamma emitter, was used to develop a novel in situ method for the radiolabeling of particles and investigation of their biodistribution. (125)I-labeled particles exhibited high stability in saline and serum over the second day, which justified their use in the following in vivo studies. The biodistribution of (125)I-labeled particles after intravenous injection in rats differed significantly: HAp particles mostly targeted the liver, HAp/Ch the spleen and the liver, while HAp/Ch-PLGA targeted the lungs. Twenty-four hours post injection, HAp particles were excreted completely, while both (125)I-HAp/Ch and (125)I-HAp/Ch-PLGA were retained in the body for a prolonged period of time with more than 20% of radioactivity still found in different organs. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. A three-dimensional finite element study on the effect of hydroxyapatite coating thickness on the stress distribution of the surrounding dental implant-bone interface

    Directory of Open Access Journals (Sweden)

    Hadi Asgharzadeh Shirazi

    2014-06-01

    Full Text Available   Background and Aims: Hydroxyapatite coating has allocated a special place in dentistry due to its biocompatibility and bioactivity. The purpose of this study was to evaluate the relation between the hydroxyapatite thickness and stress distribution by using finite element method.   Materials and Methods: In this paper, the effect of hydroxyapatite coating thickness on dental implants was studied using finite element method in the range between 0 to 200 microns. A 3D model including one section of mandible bone was modeled by a thick layer of cortical surrounding dense cancellous and a Nobel Biocare commercial brand dental implant was simulated and analyzed under static load in the Abaqus software.   Results The diagram of maximum von Mises stress versus coating thickness was plotted for the cancellous and cortical bones in the range between 0 to 200 microns. The obtained results showed that the magnitude of maximum von Mises stress of bone decreased as the hydroxyapatite coating thickness increased. Also, the thickness of coating exhibited smoother stress distribution and milder variations of maximum von Mises stress in a range between 60 to 120 microns.   Conclusion: In present study, the stress was decreased in the mandible bone where hydroxyapatite coating was used. This stress reduction leads to a faster stabilization and fixation of implant in the mandible bone. Using hydroxyapatite coating as a biocompatible and bioactive material could play an important role in bone formation of implant- bone interface.

  11. Synthesis of silver doped hydroxyapatite nanospheres using Ouzo effect

    Directory of Open Access Journals (Sweden)

    Marija Prekajski

    2016-09-01

    Full Text Available Nanoemulsion technique, based on Ouzo effect, was applied for synthesis of the pure and silver doped (2.5 and 5 mol% calcium hydroxyapatite (HAp. After calcination at 500 °C fully crystallized powders were obtained. X-ray powder diffraction analysis accompanied with Rietveld refinement revealed that the synthesized powders were single-phase hydroxyapatite. Raman spectroscopy also confirmed that the synthesized powders were single-phase. The obtained HAp particles were spherical in shape and their sizes were in the nanometer range which was revealed by field emission scanning electron microscopy analysis (FESEM. The successful synthesis of the single-phase Ag doped HAp showed that nanoemulsion method is a simple technique for obtaining pure and doped hydroxyapatite nanospheres.

  12. Hybrid biocomposites based on titania nanotubes and a hydroxyapatite coating deposited by RF-magnetron sputtering: Surface topography, structure, and mechanical properties

    Science.gov (United States)

    Chernozem, Roman V.; Surmeneva, Maria A.; Krause, Bärbel; Baumbach, Tilo; Ignatov, Viktor P.; Tyurin, Alexander I.; Loza, Kateryna; Epple, Matthias; Surmenev, Roman A.

    2017-12-01

    In this study, biocomposites based on porous titanium oxide structures and a calcium phosphate (CaP) or hydroxyapatite (HA) coating are described and prepared. Nanotubes (NTs) with different pore dimensions were processed using anodic oxidation of Ti substrates in a NH4F-containing electrolyte solution at anodization voltages of 30 and 60 V with a DC power supply. The external diameters of the nanotubes prepared at 30 V and 60 V were 53 ± 10 and 98 ± 16 nm, respectively. RF-magnetron sputtering of the HA target in a single deposition run was performed to prepare a coating on the surface of TiO2 NTs prepared at 30 and 60 V. The thickness of the CaP coating deposited on the mirror-polished Si substrate in the same deposition run with TiO2 NTs was determined by optical ellipsometry (SE) 95 ± 5 nm. Uncoated and CaP-coated NTs were annealed at 500 °C in air. Afterwards, the presence of TiO2 (anatase) was observed. The scanning electron microscopy (SEM), X-ray diffraction (XRD), photoelectron spectroscopy (XPS) and nanoindentation results revealed the influence that the NT dimensions had on the CaP coating deposition process. The tubular surfaces of the NTs were completely coated with the HA coating when prepared at 30 V, and no homogeneous CaP coating was observed when prepared at 60 V. The XRD patterns show peaks assigned to crystalline HA only for the coated TiO2 NTs prepared at 30 V. High-resolution XPS spectra show binding energies (BE) of Ca 2p, P 2p and O 1s core-levels corresponding to HA and amorphous calcium phosphate on TiO2 NTs prepared at 30 V and 60 V, respectively. Fabrication of TiO2 NTs results in a significant decrease to the elastic modulus and nanohardness compared to the Ti substrate. The porous structure of the NTs causes an increase in the elastic strain to failure of the coating (H/E) and the parameter used to describe the resistance of the material to plastic deformation (H3/E2) at the nanoscale level compared to the Ti substrate. Furthermore

  13. An integrated evidence-based targeting strategy for determining combinatorial bioactive ingredients of a compound herbal medicine Qishen Yiqi dripping pills.

    Science.gov (United States)

    Zhang, Yiqian; Yu, Jiahui; Zhang, Wen; Wang, Yuewei; He, Yi; Zhou, Shuiping; Fan, Guanwei; Yang, Hua; Zhu, Yan; Li, Ping

    2018-06-12

    Qishen Yiqi is a widely used Chinese herbal medicine formula with "qi invigorating and blood activating" property. Its dripping pill preparation (QSYQ) is a commercial herbal medicine approved by the China Food and Drug Administration (CFDA) in 2003 and is extensively used clinically to treat cardiovascular diseases, such as ischemic heart failure and angina pectoris, as well as for the secondary prevention of myocardial infarction. However, the bioactive ingredients of QSYQ remain unclear. As QSYQ is a compound herbal formula, it is of great importance to elucidate its pharmacologically active ingredients and underlying synergetic effects. This experimental study was conducted to comprehensively determine the combinatorial bioactive ingredients (CBIs) in QSYQ and to elucidate their potential synergetic effects. The established strategy may shed new light on how to rapidly determine CBIs in complex herbal formulas with holistic properties. An integrated evidence-based targeting strategy was introduced and validated to determine CBIs in QSYQ. The strategy included the following steps: (1) Chemical ingredients in QSYQ were analyzed via UPLC-Q-TOF/MS in the negative and positive modes and were identified by comparison with standard compounds and previously reported data. Their potential therapeutic activities were predicted based on the ChEMBL database to preliminarily search for candidate bioactive ingredients, and their combination was defined as the CBIs. (2) The CBIs were directly trapped and prepared from QSYQ with a two-dimensional chromatographic separation system, and the remaining part was defined as the rest ingredients (RIs). (3) As animal and cell models, left anterior descending coronary artery ligation (LAD)-induced heart failure in rats and hypoxia-induced cardiac myocyte injury in H9c2 cells were applied to compare the potency of QSYQ, CBIs and RIs. (4) The synergetic effects on cardiac myocyte protection of multiple ingredients in CBIs were examined

  14. Influence of the aspect ratio of bioactive nanofillers on rheological behavior of PMMA-based orthopedic materials.

    Science.gov (United States)

    Liu, Tse-Ying; Chen, San-Yuan; Liu, Dean-Mo

    2004-10-15

    In this investigation, calcium-deficient hydroxyapatite (CDHA) nanocrystals with needle-like geometry were synthesized and incorporated with Poly(methyl methacrylate), PMMA, to form CDHA-PMMA nanocomposites. Rheological behaviors of the PMMA-CDHA melting suspensions were systematically investigated in terms of solid loading and aspect ratio of the CDHA nanoparticles. The maximum solid loadings of nano-CDHA particles with aspect ratios of 7.2, 10.4, and 17 were determined to be 28, 31, and 57%, respectively. An increase in solid concentrations causes pronounced shear-thinning behavior. This result suggests that a strong interaction, including Van der Waals attraction and mechanical interlocking, between the nano-CDHA particles makes the nanocomposite mixture more non-Newtonian. Furthermore, it was found that packing efficiency and yield strength in the suspension were strongly influenced by the aspect ratio, especially above the critical value of 8.8. The obtained critical aspect ratio and solid content provide not only appropriate design in the PMMA-CDHA polymeric suspension for fabrication process but also optimal conditions for the fabrication of orthopedic devices via injection molding or extrusion.

  15. Vibrational algorithms for quantitative crystallographic analyses of hydroxyapatite-based biomaterials: II, application to decayed human teeth.

    Science.gov (United States)

    Adachi, Tetsuya; Pezzotti, Giuseppe; Yamamoto, Toshiro; Ichioka, Hiroaki; Boffelli, Marco; Zhu, Wenliang; Kanamura, Narisato

    2015-05-01

    A systematic investigation, based on highly spectrally resolved Raman spectroscopy, was undertaken to research the efficacy of vibrational assessments in locating chemical and crystallographic fingerprints for the characterization of dental caries and the early detection of non-cavitated carious lesions. Raman results published by other authors have indicated possible approaches for this method. However, they conspicuously lacked physical insight at the molecular scale and, thus, the rigor necessary to prove the efficacy of this spectroscopy method. After solving basic physical challenges in a companion paper, we apply them here in the form of newly developed Raman algorithms for practical dental research. Relevant differences in mineral crystallite (average) orientation and texture distribution were revealed for diseased enamel at different stages compared with healthy mineralized enamel. Clear spectroscopy features could be directly translated in terms of a rigorous and quantitative classification of crystallography and chemical characteristics of diseased enamel structures. The Raman procedure enabled us to trace back otherwise invisible characteristics in early caries, in the translucent zone (i.e., the advancing front of the disease) and in the body of lesion of cavitated caries.

  16. Effect of nitrogen and fluorine on mechanical properties and bioactivity in two series of bioactive glasses.

    Science.gov (United States)

    Bachar, Ahmed; Mercier, Cyrille; Tricoteaux, Arnaud; Hampshire, Stuart; Leriche, Anne; Follet, Claudine

    2013-07-01

    Bioactive glasses are able to bond to bone through formation of carbonated hydroxyapatite in body fluids, and fluoride-releasing bioactive glasses are of interest for both orthopaedic and, in particular, dental applications for caries inhibition. However, because of their poor strength their use is restricted to non-load-bearing applications. In order to increase their mechanical properties, doping with nitrogen has been performed on two series of bioactive glasses: series (I) was a "bioglass" composition (without P2O5) within the quaternary system SiO2-Na2O-CaO-Si3N4 and series (II) was a simple substitution of CaF2 for CaO in series (I) glasses keeping the Na:Ca ratio constant. The objective of this work was to evaluate the effect of the variation in nitrogen and fluorine content on the properties of these glasses. The density, glass transition temperature, hardness and elastic modulus all increased linearly with nitrogen content which indicates that the incorporation of nitrogen stiffens the glass network because N is mainly in 3-fold coordination with Si atoms. Fluorine addition significantly decreases the thermal property values but the mechanical properties of these glasses remain unchanged with fluorine. The combination of both nitrogen and fluorine in oxyfluoronitride glasses gives better mechanical properties at much lower melting temperatures since fluorine reduces the melting point, allows higher solubility of nitrogen and does not affect the higher mechanical properties arising from incorporation of nitrogen. The characterization of these N and F substituted bioactive glasses using (29)Si MAS NMR has shown that the increase in rigidity of the glass network can be explained by the formation of SiO3N, SiO2N2 tetrahedra and Q(4) units with extra bridging anions at the expense of Q(3) units. Bioactivity of the glasses was investigated in vitro by examining apatite formation on the surface of glasses treated in acellular simulated body fluid (SBF) with ion

  17. Preparation of bioactive porous HA/PCL composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, J.; Guo, L.Y.; Yang, X.B. [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Weng, J. [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)], E-mail: jweng@swjtu.cn

    2008-12-30

    Porous hydroxyapatite (HA) bioceramic scaffold has been widely attracted the attention to act as a three-dimensional (3D) template for cell adhesion, proliferation, differentiation and thus promoting bone and cartilage regeneration because of its osteoinduction. However, the porous bioceramic scaffold is fragile so that it is not suitable to be applied in clinic for bone repair or replacement. Therefore, it is significant to improve the mechanical property of porous HA bioceramics while the interconnected structure is maintained for tissue ingrowth in vivo. In the present research, a porous composite scaffold composed of HA scaffold and polycaprolactone (PCL) lining was fabricated by the method of polymer impregnating to produce HA scaffold coated with PCL lining. Subsequently, the composite scaffolds were deposited with biomimetic coating for improving the bioactivity. The HA/PCL composite scaffolds with improved mechanical property and bioactivity is expected to be a promising bone substitute in tissue engineering applications.

  18. Preparation of bioactive porous HA/PCL composite scaffolds

    International Nuclear Information System (INIS)

    Zhao, J.; Guo, L.Y.; Yang, X.B.; Weng, J.

    2008-01-01

    Porous hydroxyapatite (HA) bioceramic scaffold has been widely attracted the attention to act as a three-dimensional (3D) template for cell adhesion, proliferation, differentiation and thus promoting bone and cartilage regeneration because of its osteoinduction. However, the porous bioceramic scaffold is fragile so that it is not suitable to be applied in clinic for bone repair or replacement. Therefore, it is significant to improve the mechanical property of porous HA bioceramics while the interconnected structure is maintained for tissue ingrowth in vivo. In the present research, a porous composite scaffold composed of HA scaffold and polycaprolactone (PCL) lining was fabricated by the method of polymer impregnating to produce HA scaffold coated with PCL lining. Subsequently, the composite scaffolds were deposited with biomimetic coating for improving the bioactivity. The HA/PCL composite scaffolds with improved mechanical property and bioactivity is expected to be a promising bone substitute in tissue engineering applications

  19. Hibiscus sabdariffa L. and Its Bioactive Constituents Exhibit Antiviral Activity against HSV-2 and Anti-enzymatic Properties against Urease by an ESI-MS Based Assay

    Directory of Open Access Journals (Sweden)

    Sherif T. S. Hassan

    2017-04-01

    Full Text Available For decades, Hibiscus sabdariffa L. and its phytochemicals have been shown to possess a wide range of pharmacologic properties. In this study, aqueous extract of Hibiscus sabdariffa (AEHS and its bioactive constituent protocatechuic acid (PCA, have been evaluated in vitro for their antiviral activity against HSV-2 clinical isolates and anti-enzymatic activity against urease. Antiherpetic activity was evaluated by the titer reduction assay in infected Vero cells, and cytotoxicity was evaluated by the neutral red dye-uptake method. Anti-urease activity was determined by a developed Electrospray Ionization-Mass Spectrometry (ESI-MS-based assay. PCA showed potent anti-HSV-2 activity compared with that of acyclovir, with EC50 values of 0.92 and 1.43 µg∙mL−1, respectively, and selectivity indices > 217 and > 140, respectively. For the first time, AEHS was shown to exert anti-urease inhibition activity, with an IC50 value of 82.4 µg∙mL−1. This, combined with its safety, could facilitate its use in practical applications as a natural urease inhibitor. Our results present Hibiscus sabdariffa L. and its bioactive compound PCA as potential therapeutic agents in the treatment of HSV-2 infection and the treatment of diseases caused by urease-producing bacteria.

  20. Hibiscus sabdariffa L. and Its Bioactive Constituents Exhibit Antiviral Activity against HSV-2 and Anti-enzymatic Properties against Urease by an ESI-MS Based Assay.

    Science.gov (United States)

    Hassan, Sherif T S; Švajdlenka, Emil; Berchová-Bímová, Kateřina

    2017-04-30

    For decades, Hibiscus sabdariffa L. and its phytochemicals have been shown to possess a wide range of pharmacologic properties. In this study, aqueous extract of Hibiscus sabdariffa (AEHS) and its bioactive constituent protocatechuic acid (PCA), have been evaluated in vitro for their antiviral activity against HSV-2 clinical isolates and anti-enzymatic activity against urease. Antiherpetic activity was evaluated by the titer reduction assay in infected Vero cells, and cytotoxicity was evaluated by the neutral red dye-uptake method. Anti-urease activity was determined by a developed Electrospray Ionization-Mass Spectrometry (ESI-MS)-based assay. PCA showed potent anti-HSV-2 activity compared with that of acyclovir, with EC 50 values of 0.92 and 1.43 µg∙mL -1 , respectively, and selectivity indices > 217 and > 140, respectively. For the first time, AEHS was shown to exert anti-urease inhibition activity, with an IC 50 value of 82.4 µg∙mL -1 . This, combined with its safety, could facilitate its use in practical applications as a natural urease inhibitor. Our results present Hibiscus sabdariffa L. and its bioactive compound PCA as potential therapeutic agents in the treatment of HSV-2 infection and the treatment of diseases caused by urease-producing bacteria.

  1. Towards the synthesis of an experimental bioactive dental ceramic. Part I: Crystallinity characterization and bioactive behavior evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Goudouri, O.-M. [Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kontonasaki, E. [School of Dentistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Papadopoulou, L.; Kantiranis, N. [Department of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Lazaridis, N.K. [Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chrissafis, K.; Chatzistavrou, X. [Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Koidis, P. [School of Dentistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Paraskevopoulos, K.M., E-mail: kpar@auth.gr [Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2014-05-01

    An attachment between the dental ceramic and the surrounding marginal tissues in fixed prosthetic restorations could eliminate secondary carries prevalence. The development of dental ceramics with apatite forming ability could provide the biological surface required for selective spread and attachment of specific cell types able to promote tissue attachment. Dental ceramics/bioactive glass composites synthesized by the sol gel method have been previously reported to develop carbonated hydroxyapatite (HCAp) in biomimetic solutions, requiring though a high amount of bioactive glass, which resulted in the compromise of their mechanical integrity. Thus, the aim of the present work was the synthesis and characterization of an experimental sol–gel derived dental ceramic with low amount of bioactive glass and the evaluation of its in vitro bioactivity. Differential thermal and thermogravimetric analysis (TG–DTA), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to evaluate the crystal structure and the in vitro apatite forming ability of the synthesized material. The results of this study indicated the successful sol–gel synthesis of an experimental dental ceramic containing low amount of bioactive glass that presented similar structural and morphological characteristics with a commercial feldspathic dental ceramic, while exhibiting in vitro bioactivity. The apatite forming ability of the experimental sol–gel derived feldspathic dental ceramic may trigger the appropriate cellular mechanisms towards the establishment of attachment with the surrounding connective tissue. This attachment could provide a barrier to oral bacteria penetration, prolonging the life expectation of the restorations. - Highlights: • Synthesis of a bioactive sol–gel dental ceramic for fixed prosthetic restorations. • The sol–gel technique promoted the crystallization of

  2. Towards the synthesis of an experimental bioactive dental ceramic. Part I: Crystallinity characterization and bioactive behavior evaluation

    International Nuclear Information System (INIS)

    Goudouri, O.-M.; Kontonasaki, E.; Papadopoulou, L.; Kantiranis, N.; Lazaridis, N.K.; Chrissafis, K.; Chatzistavrou, X.; Koidis, P.; Paraskevopoulos, K.M.

    2014-01-01

    An attachment between the dental ceramic and the surrounding marginal tissues in fixed prosthetic restorations could eliminate secondary carries prevalence. The development of dental ceramics with apatite forming ability could provide the biological surface required for selective spread and attachment of specific cell types able to promote tissue attachment. Dental ceramics/bioactive glass composites synthesized by the sol gel method have been previously reported to develop carbonated hydroxyapatite (HCAp) in biomimetic solutions, requiring though a high amount of bioactive glass, which resulted in the compromise of their mechanical integrity. Thus, the aim of the present work was the synthesis and characterization of an experimental sol–gel derived dental ceramic with low amount of bioactive glass and the evaluation of its in vitro bioactivity. Differential thermal and thermogravimetric analysis (TG–DTA), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to evaluate the crystal structure and the in vitro apatite forming ability of the synthesized material. The results of this study indicated the successful sol–gel synthesis of an experimental dental ceramic containing low amount of bioactive glass that presented similar structural and morphological characteristics with a commercial feldspathic dental ceramic, while exhibiting in vitro bioactivity. The apatite forming ability of the experimental sol–gel derived feldspathic dental ceramic may trigger the appropriate cellular mechanisms towards the establishment of attachment with the surrounding connective tissue. This attachment could provide a barrier to oral bacteria penetration, prolonging the life expectation of the restorations. - Highlights: • Synthesis of a bioactive sol–gel dental ceramic for fixed prosthetic restorations. • The sol–gel technique promoted the crystallization of

  3. Bioactive protein-based nanofibers interact with intestinal biological components resulting in transepithelial permeation of a therapeutic protein

    DEFF Research Database (Denmark)

    Boutrup Stephansen, Karen; García-Díaz, María; Jessen, Flemming

    2015-01-01

    Proteins originating from natural sources may constitute a novel type of material for use in drug delivery. However, thorough understanding of the behavior and effects of such a material when processed into a matrix together with a drug is crucial prior to further development into a drug product....... In the present study the potential of using bioactive electrospun fish sarcoplasmic proteins (FSP) as a carrier matrix for small therapeutic proteins was demonstrated in relation to the interactions with biological components of the intestinal tract. The inherent structural and chemical properties of FSP...... as a biomaterial facilitated interactions with cells and enzymes found in the gastrointestinal tract and displayed excellent biocompatibility. More specifically, insulin was efficiently encapsulated into FSP fibers maintaining its conformation, and subsequent controlled release was obtained in simulated intestinal...

  4. Protein-adsorption and Ca-phosphate formation on chitosan-bioactive glass composite coatings

    Science.gov (United States)

    Wagener, V.; Boccaccini, A. R.; Virtanen, S.

    2017-09-01

    In the last years, chitosan-bioactive glass (BG) composites have been developed and investigated as bioactive coatings for orthopedic applications. The increase of bioactivity occurs due to the stimulation of calcium-phosphate/hydroxyapatite formation on the surface while the coating is degrading. In the present work, protein adsorption and its influence on calcium-phosphate precipitation was studied for the first time on such composite coatings. The experiments involved coating of 316L stainless steel substrates with chitosan (Ch) and chitosan-bioactive glass (Ch-BG) and immersion of the coated samples in two different bovine serum albumin (BSA) containing solutions, namely DI H2O (with pH adjusted to about 7.2 with diluted NaOH) and simulated body fluid (SBF). In order to investigate the influence of protein adsorption on calcium-phosphate precipitation, samples were also immersed in DI H2O and in SBF without BSA. Samples were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Surface analysis revealed that adsorption of BSA takes place on all studied samples and that protein adsorption is influenced by the presence of Ca2+ and PO43- ions. Bioactivity in the form of hydroxyapatite pre-stage formation is significantly increased on Ch-BG composite coating as compared with bare stainless steel surface. However, calcium-phosphate precipitation in SBF is reduced by the presence of BSA.

  5. Ceria-containing uncoated and coated hydroxyapatite-based galantamine nanocomposites for formidable treatment of Alzheimer's disease in ovariectomized albino-rat model.

    Science.gov (United States)

    Wahba, Sanaa M R; Darwish, Atef S; Kamal, Sara M

    2016-08-01

    This paper upraises delivery and therapeutic actions of galantamine drug (GAL) against Alzheimer's disease (AD) in rat brain through attaching GAL to ceria-containing hydroxyapatite (GAL@Ce-HAp) as well ceria-containing carboxymethyl chitosan-coated hydroxyapatite (GAL@Ce-HAp/CMC) nanocomposites. Physicochemical features of such nanocomposites were analyzed by XRD, FT-IR, Raman spectroscopy, UV-vis spectrophotometer, N2-BET, DLS, zeta-potential measurements, SEM, and HR-TEM. Limited interactions were observed in GAL@Ce-HAp with prevailed existence of dispersed negatively charged rod-like particles conjugated with ceria nanodots. On contrary, GAL@Ce-HAp/CMC was well-structured developing aggregates of uncharged tetragonal-shaped particles laden with accession of ceria quantum dots. Such nanocomposites were i.p. injected into ovariectomized AD albino-rats at galantamine dose of 2.5mg/kg/day for one month, then brain tissues were collected for biochemical and histological tests. GAL@Ce-HAp adopted as a promising candidate for AD curativeness, whereas oxidative stress markers were successfully upregulated, degenerated neurons in hippocampal and cerebral tissues were wholly recovered and Aβ-plaques were vanished. Also, optimizable in-vitro release for GAL and nanoceria were displayed from GAL@Ce-HAp, while delayed in-vitro release for those species were developed from GAL@Ce-HAp/CMC. This proof of concept work allow futuristic omnipotency of rod-like hydroxyapatite particles for selective delivery of GAL and nanoceria to AD affected brain areas. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Rational design of a high-strength bone scaffold platform based on in situ hybridization of bacterial cellulose/nano-hydroxyapatite framework and silk fibroin reinforcing phase.

    Science.gov (United States)

    Jiang, Pei; Ran, Jiabing; Yan, Pan; Zheng, Lingyue; Shen, Xinyu; Tong, Hua

    2018-02-01

    Bacterial cellulose/hydroxyapatite (BC/HAp) composite had favourable bioaffinity but its poor mechanical strength limited its widespread applications in bone tissue engineering (BTE). Silk fibroin, which possesses special crystalline structure, has been widely used as organic reinforcing material, and different SFs have different amino acid sequences, which exhibit different bioaffinity and mechanical properties. In this regard, bacterial cellulose-Antheraea yamamai silk fibroin/hydroxyapatite (BC-AYSF/HAp), bacterial cellulose-Bombyx mori silk fibroin/hydroxyapatite (BC-BMSF/HAp), and BC/HAp nano-composites were synthesized via a novel in situ hybridization method. Compared with BC/HAp and BC-BMSF/HAp, the BC-AYSF/HAp exhibited better interpenetration, which may benefit for the transportation of nutrients and wastes, the adhesion of cells as well. Additionally, the BC-AYSF/HAp also presented superior thermal stability than the other two composites revealed by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). Compression testing indicated that the mechanical strength of BC-BMSF/HAp was greatly reinforced compared with BC/HAp and was even a little higher than that of BC-AYSF/HAp. Tensile testing showed that BC-AYSF/HAp possesses extraordinary mechanical properties with a higher elastic modulus at low strain and higher fracture strength simultaneously than the other two composites. In vitro cell culture exhibited that MC3T3-E1 cells on the BC-AYSF/HAp membrane took on higher proliferative potential than those on the BC-BMSF/HAp membrane. These results suggested that compared with BC-BMSF/HAp, the BC-AYSF/HAp composite was more appropriate as an ideal bone scaffold platform or biomedical membrane to be used in BTE.

  7. Dispersed hydroxyapatite and modified bioglass 45S5 composites: sintering behavior of glass matrix ranging from 20 to 30 wt% in calcium oxide investigation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.C.; Parra-Silva, J.; Santos, S.C.; Mello-Castanho, S.R.H, E-mail: dasilva.ac@uol.com.br [Instituto de Pesquisas Enegeticas e Nucleares (IPEN/CNEN-SP), DP (Brazil); Braga, F.J.C. [Consulmat Materiais de Referencia, Solucoes e Servicos, Sao Carlos, SP (Brazil); Setz, L.F.G. [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2014-07-01

    Biomaterial technology plays an important role in cell-based tissue proliferation environment creation. The hydroxyapatite (HA) bioceramics are reference materials to employment as a bone substitute, however, their slow rate of degradation and its low rate of bioactivity (Ib) are presented as limiting factors for application as bone graft. In contrast, the bioglass (BG) is a resorbable and osteoinductive material and can act as fluxing in HA/BG composites. The present work objective the development of HA/BG (40/70wt%) composites, Three compositions of the 45S5 bioglass derived ranging from 20-30wt% in CaO were used in order to study the sintering behavior of these materials with hydroxyapatite 30wt% dispersed. The composites were uniaxially pressed in the form of cylinders and sinterized at (1100°C/1h). The characterization was made employing scanning electron microscopy, Infra-Red Spectrometry, X-ray diffraction and hydrolytic resistance test. The results indicate the potential use of the materials developed for applications like bone graft.(author)

  8. Dispersed hydroxyapatite and modified bioglass 45S5 composites: sintering behavior of glass matrix ranging from 20 to 30 wt% in calcium oxide investigation

    International Nuclear Information System (INIS)

    Silva, A.C.; Parra-Silva, J.; Santos, S.C.; Mello-Castanho, S.R.H; Braga, F.J.C.; Setz, L.F.G.

    2014-01-01

    Biomaterial technology plays an important role in cell-based tissue proliferation environment creation. The hydroxyapatite (HA) bioceramics are reference materials to employment as a bone substitute, however, their slow rate of degradation and its low rate of bioactivity (Ib) are presented as limiting factors for application as bone graft. In contrast, the bioglass (BG) is a resorbable and osteoinductive material and can act as fluxing in HA/BG composites. The present work objective the development of HA/BG (40/70wt%) composites, Three compositions of the 45S5 bioglass derived ranging from 20-30wt% in CaO were used in order to study the sintering behavior of these materials with hydroxyapatite 30wt% dispersed. The composites were uniaxially pressed in the form of cylinders and sinterized at (1100°C/1h). The characterization was made employing scanning electron microscopy, Infra-Red Spectrometry, X-ray diffraction and hydrolytic resistance test. The results indicate the potential use of the materials developed for applications like bone graft.(author)

  9. Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity

    Directory of Open Access Journals (Sweden)

    Boguslawa Żywicka

    2017-10-01

    Full Text Available Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide, (PLGA, and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate (PLGA/PHB. The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals.

  10. Synthesis and characterization of hydroxyapatite (HAp) for binder tungstate in 188W/188Re generator system

    International Nuclear Information System (INIS)

    Eni Hartati; Yati B Yuliyati; Duyeh Setiawan

    2014-01-01

    In this study, the synthesis of hydroxyapatite has been carried out through a process of precipitation of calcium hydroxide (Ca(OH) 2 ) with phosphoric acid (H 3 PO 4 ) based on acid base reaction process that produce crystalline solid and then it will be used for binder tungstate in 188 W/ 188 Re generator system. The purpose of this study were to characterize the results of synthesized hydroxyapatite and to determine the optimum conditions on generator 188 W/ 188 Re performance such as activation of the heating hydroxyapatite, pH of Na 2 WO 4 , reaction temperature, distribution coefficient and the adsorption capacity (adsorption coefficient) of hydroxyapatite. The characterization of synthesized hydroxyapatite was done using FTIR, XRD and SEM-EDAX, while the determination of the optimum condition of each parameters based on distribution coefficient and adsorption capacity hydroxyapatite using spectrophotometric method. The FTIR results of hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ) showed the appearance of peaks in the O-H stretching wave number (υ) and 3434.9 cm -1 and 563.8 cm -1 , while the group PO 4 -3 is shown by the P-O bond in (υ) 1033.8 cm -1 . The XRD results indicate that hydroxyapatite had three peaks at 2θ region is 31,875° , 32,205° and 33,080°. Characterization by SEM showed columnar morphology with a particle size of 200 nm. The optimum conditions of each parameter obtained at hydroxyapatite heating temperature 100 °C, Na 2 WO 4 solution pH 3, and the reaction temperature of 60 °C, which gave result on distribution coefficients of 193.74 mL/g and adsorption capacity (adsorption coefficient) of 5.20 mg W/g HAp. (author)

  11. Synthesis and characterization of nanocrystalline hydroxyapatite gel and its application as scaffold aggregation

    Directory of Open Access Journals (Sweden)

    Leonardo Ribeiro Rodrigues

    2012-12-01

    Full Text Available The sol-gel process is a technique used to synthesize materials from colloidal suspensions and, therefore, is suitable for preparing materials in the nanoscale. In this work hydroxyapatite was used due to its known properties in tissue engineering. Hydroxyapatite Ca10(PO46(OH2 is a bioactive ceramic which is found in the mineral phase of bone tissue and is known for its great potential in tissue engineering applications. For this reason, this material can be applied as particle aggregates on ceramic slurry, coating or film on materials with a poorer biological response than hydroxyapatite. In this work, hydroxyapatite gel was obtained by the sol-gel process and applied as nanoparticle aggregation in the mixture of hydroxyapatite and tricalcium phosphate to form a ceramic slurry. This process is the polymer foam replication technique used to produce scaffolds, which are used in tissue engineering. For HA gel characterization it was used enviromental scanning electron microscopy (ESEM, transmission electron microscopy (TEM, electron energy loss spectroscopy (EELS, scanning electron microscopy (SEM, X-ray diffraction (XRD and X-ray fluorescence (XRF. The crystallite size was calculated from XRD data using the Scherrer equation. The nanoparticles size before firing was approximately 5nm. The crystallite size calculated after calcination was approximately 63 nm. The EELS results showed that calcium phosphate was obtained before firing. After HA gel calcination at 500 ºC the XRD results showed hydroxyapatite with a small content of beta-TCP. The scaffolds obtained by polymer foam replication technique showed a morphology with adequate porosity for tissue engineering.

  12. Calcium silicate ceramic scaffolds toughened with hydroxyapatite whiskers for bone tissue engineering

    International Nuclear Information System (INIS)

    Feng, Pei; Wei, Pingpin; Li, Pengjian; Gao, Chengde; Shuai, Cijun; Peng, Shuping

    2014-01-01

    Calcium silicate possessed excellent biocompatibility, bioactivity and degradability, while the high brittleness limited its application in load-bearing sites. Hydroxyapatite whiskers ranging from 0 to 30 wt.% were incorporated into the calcium silicate matrix to improve the strength and fracture resistance. Porous scaffolds were fabricated by selective laser sintering. The effects of hydroxyapatite whiskers on the mechanical properties and toughening mechanisms were investigated. The results showed that the scaffolds had a uniform and continuous inner network with the pore size ranging between 0.5 mm and 0.8 mm. The mechanical properties were enhanced with increasing hydroxyapatite whiskers, reached a maximum at 20 wt.% (compressive strength: 27.28 MPa, compressive Young's modulus: 156.2 MPa, flexural strength: 15.64 MPa and fracture toughness: 1.43 MPa·m 1/2 ) and then decreased by addition of more hydroxyapatite whiskers. The improvement of mechanical properties was due to whisker pull-out, crack deflection and crack bridging. Moreover, the degradation rate decreased with the increase of hydroxyapatite whisker content. A layer of bone-like apatite was formed on the scaffold surfaces after being soaked in simulated body fluid. Human osteoblast-like MG-63 cells spread well on the scaffolds and proliferated with increasing culture time. These findings suggested that the calcium silicate scaffolds reinforced with hydroxyapatite whiskers showed great potential for bone regeneration and tissue engineering applications. - Highlights: • HA whiskers were incorporated into CS to improve the properties. • The scaffolds were successfully fabricated by SLS. • Toughening mechanisms was whisker pull-out, crack deflection and bridging. • The scaffolds showed excellent apatite forming ability

  13. Hydrothermal synthesis of hydroxyapatite nanoparticles decorated with silver nanoparticles for application in biomaterials

    International Nuclear Information System (INIS)

    Assis, Jordanna Fernandes; Arantes, Tatiane Moraes; Cristovan, F.H.; Tada, Dayane Batista

    2016-01-01

    Full text: The hydroxyapatite nanoparticles (HA) have research attention because are material that exhibit biocompatibility with bone mineral phase of human body is great interest in the scientific community. Synthetic hydroxyapatite nanoparticles have excellent biocompatibility and bioactivity, due biocompatibility and osteo inducibility [1-3]. The hydroxyapatite nanoparticles were synthesized by hydrothermal processing and were characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM). The XRD and Raman spectra showed crystalline hydroxyapatite colloidal nanoparticles were obtained in the hexagonal phase. XRD measure showed silver diffraction peaks cubic phase confirmed the presence of the silver nanoparticles decorated hydroxyapatite surface. TEM images showed HA nanoparticles presented a well defined nanorod shapes and narrow size distributions with dimensions (width and length) around of 5 nm and 50 nm decorated with silver nanoparticles of spherical shape about 20 nm in diameter The results showed that crystalline hydroxyapatite colloidal nanoparticles with rod-like morphology and uniform decorated with silver spherical nanoparticles size were obtained by hydrothermal synthesis. These nanoparticles The cell viability of the HA and HA/Ag was analyzed by reduction of the tetrazolium salt (MTT test). Embryonic mouse fibroblast cells were grown in the presence of nanoparticles for a total period of 96 hours. Analyses were made in 24h, 48h, 72h and 96h. The suspensions at the end of each period were analyzed in spectrophotometer. The 24h experiments were the most conclusive, with the silver presence in the HA, there is an increased in cellular proliferation. The results demonstrated that the HA/Ag nanoparticles have potential use as biomaterials in medical/odontological applications. (author)

  14. Calcium silicate ceramic scaffolds toughened with hydroxyapatite whiskers for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Pei [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Wei, Pingpin [Cancer Research Institute, Central South University, Changsha 410078 (China); Li, Pengjian; Gao, Chengde [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Shuai, Cijun, E-mail: shuai@csu.edu.cn [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425 (United States); Peng, Shuping, E-mail: shuping@csu.edu.cn [Cancer Research Institute, Central South University, Changsha 410078 (China)

    2014-11-15

    Calcium silicate possessed excellent biocompatibility, bioactivity and degradability, while the high brittleness limited its application in load-bearing sites. Hydroxyapatite whiskers ranging from 0 to 30 wt.% were incorporated into the calcium silicate matrix to improve the strength and fracture resistance. Porous scaffolds were fabricated by selective laser sintering. The effects of hydroxyapatite whiskers on the mechanical properties and toughening mechanisms were investigated. The results showed that the scaffolds had a uniform and continuous inner network with the pore size ranging between 0.5 mm and 0.8 mm. The mechanical properties were enhanced with increasing hydroxyapatite whiskers, reached a maximum at 20 wt.% (compressive strength: 27.28 MPa, compressive Young's modulus: 156.2 MPa, flexural strength: 15.64 MPa and fracture toughness: 1.43 MPa·m{sup 1/2}) and then decreased by addition of more hydroxyapatite whiskers. The improvement of mechanical properties was due to whisker pull-out, crack deflection and crack bridging. Moreover, the degradation rate decreased with the increase of hydroxyapatite whisker content. A layer of bone-like apatite was formed on the scaffold surfaces after being soaked in simulated body fluid. Human osteoblast-like MG-63 cells spread well on the scaffolds and proliferated with increasing culture time. These findings suggested that the calcium silicate scaffolds reinforced with hydroxyapatite whiskers showed great potential for bone regeneration and tissue engineering applications. - Highlights: • HA whiskers were incorporated into CS to improve the properties. • The scaffolds were successfully fabricated by SLS. • Toughening mechanisms was whisker pull-out, crack deflection and bridging. • The scaffolds showed excellent apatite forming ability.

  15. Hydrothermal synthesis of hydroxyapatite nanoparticles decorated with silver nanoparticles for application in biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Assis, Jordanna Fernandes; Arantes, Tatiane Moraes, E-mail: fernandes.jordanna9@gmail.com [Universidade Federal de Goias (UFG), Goiania (Brazil); Cristovan, F.H.; Tada, Dayane Batista [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil)

    2016-07-01

    Full text: The hydroxyapatite nanoparticles (HA) have research attention because are material that exhibit biocompatibility with bone mineral phase of human body is great interest in the scientific community. Synthetic hydroxyapatite nanoparticles have excellent biocompatibility and bioactivity, due biocompatibility and osteo inducibility [1-3]. The hydroxyapatite nanoparticles were synthesized by hydrothermal processing and were characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM). The XRD and Raman spectra showed crystalline hydroxyapatite colloidal nanoparticles were obtained in the hexagonal phase. XRD measure showed silver diffraction peaks cubic phase confirmed the presence of the silver nanoparticles decorated hydroxyapatite surface. TEM images showed HA nanoparticles presented a well defined nanorod shapes and narrow size distributions with dimensions (width and length) around of 5 nm and 50 nm decorated with silver nanoparticles of spherical shape about 20 nm in diameter The results showed that crystalline hydroxyapatite colloidal nanoparticles with rod-like morphology and uniform decorated with silver spherical nanoparticles size were obtained by hydrothermal synthesis. These nanoparticles The cell viability of the HA and HA/Ag was analyzed by reduction of the tetrazolium salt (MTT test). Embryonic mouse fibroblast cells were grown in the presence of nanoparticles for a total period of 96 hours. Analyses were made in 24h, 48h, 72h and 96h. The suspensions at the end of each period were analyzed in spectrophotometer. The 24h experiments were the most conclusive, with the silver presence in the HA, there is an increased in cellular proliferation. The results demonstrated that the HA/Ag nanoparticles have potential use as biomaterials in medical/odontological applications. (author)

  16. The Effect of Hydroxyapatite Coatings on the Passivation Behavior of Oxidized and Unoxidized Superelastic Nitinol Alloys

    Science.gov (United States)

    Etminanfar, M. R.; Khalil-Allafi, J.; Sheykholeslami, S. O. R.

    2018-02-01

    Nitinol alloys have been used in various biological applications due to their superior properties. In this study, a bipolar pulsed current electrodeposition technique was applied to produce a hydroxyapatite (HA) film on the Nitinol alloy. Also, the protection performance of the coating was evaluated on both abraded and thermochemically modified alloy. According to obtained data, reducing the electrocrystallization rate by the pulse deposition technique can promote HA formation on both abraded and modified substrates. Based on scanning electron microscopy and high-resolution transmission electron microscopy data, the HA coatings revealed a flake-like morphology and each flake was composed of nano-crystalline grains. Atomic force microscopy images revealed that flakes on the abraded substrate were smaller in size than that of the modified alloy. Comparing the corrosion resistance of the bare substrates revealed that the modified alloy has a higher corrosion resistance than the abraded alloy and the modified surface is well passivized during anodic polarization in Ringer's solution. However, this condition is reversed after the deposition of HA film. It seems that because of the lower crystallization sites on the abraded alloy, the produced HA film is denser and more protective against the corrosive mediums as compared to the coating on the modified alloy. Although the HA coating can improve the bioactivity of both substrates, the resulted film on the oxidized alloy is porous and deteriorates the implant permanence in the vicinity of body fluids.

  17. Novel cerium doped glass-reinforced hydroxyapatite with antibacterial and osteoconductive properties for bone tissue regeneration

    International Nuclear Information System (INIS)

    Morais, D S; Fernandes, S; Santos, J D; Lopes, M A; Gomes, P S; Fernandes, M H; Sampaio, P; Ferraz, M P; Sooraj Hussain, N

    2015-01-01

    The aim of this work was to develop a bioactive bone substitute with an effective antibacterial ability based on a cerium (Ce) doped glass-reinforced hydroxyapatite (GR-HA) composite. Developed composites were physicochemically characterized, using x-ray diffraction (XRD) analysis, SEM, energy dispersive x-ray spectroscopy (EDS), and flexural bending strength (FBS) tests. X-ray photoelectron spectroscopy (XPS) analysis was performed to analyze the oxidation state of Ce in the prepared doped glass. The antimicrobial activity of the composites was evaluated against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa; whether the cytocompatibility profile was assayed with human osteoblastic-like cells (Mg-63 cell line). The results revealed that the Ce inclusion in the GR-HA matrix induced the antimicrobial ability of the composite. In addition, Ce-doped materials reported an adequate biological behavior following seeding of osteoblastic populations, by inducing cell adhesion and proliferation. Developed materials were also found to enhance the expression of osteoblastic-related genes. Overall, the developed GR-HA-Ce composite is a prospective candidate to be used within the clinical scenario with a successful performance due to the effective antibacterial properties and capability of enhancing the osteoblastic cell response. (paper)

  18. An improved biofunction of titanium for keratoprosthesis by hydroxyapatite-coating.

    Science.gov (United States)

    Dong, Ying; Yang, Jingxin; Wang, Liqiang; Ma, Xiao; Huang, Yifei; Qiu, Zhiye; Cui, Fuzhai

    2014-03-01

    Titanium framework keratoprosthesis has been commonly used in the severe corneal blindness, but the tissue melting occurred frequently around titanium. Since hydroxyapatite has been approved to possess a good tissue integration characteristic, nanostructured hydroxyapatite was coated on the surface of titanium through the aerosol deposition method. In this study, nanostructured hydroxyapatite coating was characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and auger electronic spectrometer. Biological evaluations were performed with rabbit cornea fibroblast in vitro and an animal model in vivo. The outcomes showed the coating had a grain-like surface topography and a good atomic mixed area with substrate. The rabbit cornea fibroblasts appeared a good adhesion on the surface of nanostructured hydroxyapatite in vitro. In the animal model, nanostructured hydroxyapatite-titanium implants were stably retained in the rabbit cornea, and by contrast, the corneal stroma became thinner anterior to the implants in the control. Therefore, our findings proved that nanostructured hydroxyapatite-titanium could not only provide an improved bond for substrate but also enhance the tissue integration with implants in host. As a promising material, nanostructured hydroxyapatite-titanium-based keratoprosthesis prepared by the aerosol deposition method could be utilized for the corneal blindness treatment.

  19. Dynamics of CTAB in hybrid CTAB-hydroxyapatite system

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, P., E-mail: purushd@barc.gov.in; Sharma, V. K.; Mitra, S.; Mukhopadhyay, R. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 40085 (India); Verma, G.; Hassan, P. A. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai, 40085 (India); Johnson, M. [Institut Laue-Langevin, BP 156, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)

    2016-05-23

    Synthetic hydroxyapatite (HAp) is an important material in biomedical engineering due to its excellent biocompatibility and bioactivity. Here we report dynamics of cetyltrimethylammonium bromide (CTAB) in HAp composite, prepared by co-precipitation method, as studied by quasielastic neutron scattering (QENS) technique. It is found that the observed dynamics involved two time scales associated with fast torsional motion and segmental motion of the CTAB monomers. In addition to segmental motion of the hydrogen atoms, few undergo torsional motion as well. Torsional dynamics was described by a 2-fold jump diffusion model. The segmental dynamics of CTAB has been described assumimg the hydrogen atoms undergoing diffusion inside a sphere of confined volume. While the diffusivity is found to increase with temperature, the spherical volumes within which the hydrogen atoms are undergoing diffusion remain almost unchanged.

  20. Improved bonding strength of bioactive cermet Cold Gas Spray coatings.

    Science.gov (United States)

    Gardon, M; Concustell, A; Dosta, S; Cinca, N; Cano, I G; Guilemany, J M

    2014-12-01

    The fabrication of cermet biocompatible coatings by means Cold Gas Spray (CGS) provides prosthesis with outstanding mechanical properties and the required composition for enhancing the bioactivity of prosthetic materials. In this study, hydroxyapatite/Titanium coatings were deposited by means of CGS technology onto titanium alloy substrates with the aim of building-up well-bonded homogeneous coatings. Powders were blended in different percentages and sprayed; as long as the amount of hydroxyapatite in the feedstock increased, the quality of the coating was reduced. Besides, the relation between the particle size distribution of ceramic and metallic particles is of significant consideration. Plastic deformation of titanium particles at the impact eased the anchoring of hard hydroxyapatite particles present at the top surface of the coating, which assures the looked-for interaction with the cells. Coatings were immersed in Hank's solution for 1, 4 and 7 days; bonding strength value was above 60 MPa even after 7 days, which enhances common results of HAp coatings obtained by conventional thermal spray technologies. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Fabrication and characterization of strontium incorporated 3-D bioactive glass scaffolds for bone tissue from biosilica

    Energy Technology Data Exchange (ETDEWEB)

    Özarslan, Ali Can, E-mail: alicanozarslan@gmail.com; Yücel, Sevil, E-mail: syucel@yildiz.edu.tr

    2016-11-01

    Bioactive glass scaffolds that contain silica are high viable biomaterials as bone supporters for bone tissue engineering due to their bioactive behaviour in simulated body fluid (SBF). In the human body, these materials help inorganic bone structure formation due to a combination of the particular ratio of elements such as silicon (Si), calcium (Ca), sodium (Na) and phosphorus (P), and the doping of strontium (Sr) into the scaffold structure increases their bioactive behaviour. In this study, bioactive glass scaffolds were produced by using rice hull ash (RHA) silica and commercial silica based bioactive glasses. The structural properties of scaffolds such as pore size, porosity and also the bioactive behaviour were investigated. The results showed that undoped and Sr-doped RHA silica-based bioactive glass scaffolds have better bioactivity than that of commercial silica based bioactive glass scaffolds. Moreover, undoped and Sr-doped RHA silica-based bioactive glass scaffolds will be able to be used instead of undoped and Sr-doped commercial silica based bioactive glass scaffolds for bone regeneration applications. Scaffolds that are produced from undoped or Sr-doped RHA silica have high potential to form new bone for bone defects in tissue engineering. - Highlights: • Production of 3-D bioactive glass scaffolds from different silica sources • The effect of biosilica from rice hull ash on the bioactive glass scaffold • Sr additive impact on the bioactivity and biodegradability properties of scaffolds.

  2. Formation of carrageenan-CaCO{sub 3} bioactive membranes

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Lucas F.B.; Maniglia, Bianca C.; Pereira, Lourivaldo S.; Tapia-Blácido, Delia R.; Ramos, Ana P., E-mail: anapr@ffclrp.usp.br

    2016-01-01

    The high biocompatibility and resorbability of polymeric membranes have encouraged their use to manufacture medical devices. Here, we report on the preparation of membranes consisting of carrageenan, a naturally occurring sulfated polysaccharide that forms helical structures in the presence of calcium ions. We incorporated CaCO{sub 3} particles into the membranes to enhance their bioactivity and mechanical properties. Infrared spectroscopy and X-ray diffraction data confirmed CaCO{sub 3} incorporation into the polymeric matrix. We tested the bioactivity of the samples by immersing them in a solution that mimics the ionic composition and pH of the human body fluid. The hybrid membranes generated hydroxyapatite, as attested by X-ray diffraction data. Scanning electron and atomic force microscopies aided investigation of membrane topography before and after CaCO{sub 3} deposition. The wettability and surface free energy, evaluated by contact angle measures, increased in the presence of CaCO{sub 3} particles. These parameters are important for membrane implantation in the body. Moreover, membrane stiffness was up to 110% higher in the presence of the inorganic particles, as revealed by Young's modulus. - Highlights: • Hybrid kappa and iota carrageenan-CaCO{sub 3} membranes were formed. • The hybrid membrane's origin hydroxyapatite after exposure to simulated body fluid • The carrageenan's specificity to bind Ca{sup 2+} ions tailors the surface properties.

  3. Alendronate functionalized mesoporous hydroxyapatite nanoparticles for drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dongdong, E-mail: lidongchem@sina.cn [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China); Zhu, Yuntao; Liang, Zhiqiang [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China)

    2013-06-01

    Highlights: ► The synthesized mesoporous hydroxyapatite has nanostructure and bioactivity. ► The materials have high surface area and amino group. ► The materials show higher drug loading and slower release rate than pure HAP. - Abstract: Mesoporous nanosized hydroxyapatite (HAP) functionalized by alendronate (ALN) was synthesized using cationic surfactant CTAB as template. The structural, morphological and textural properties were fully characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy