Wear characterization of nano-hydroxyapatite with addition of titanium (HA-Ti)

Science.gov (United States)

Rosmamuhamadani, R.; Arawi, A. Z. O.; Talari, M. K.; Mahat, M. M.; Bonnia, N. N.; Sabrina; Yahaya, M.; Sulaiman, S.; Ismail, M. I. S.

2018-04-01

Hydroxyapatite (Ca10 (PO4)6(OH)2, HA), is an attractive material of an inorganic compound whose chemical composition and crystallographic structures are similar to the composition of the bone. A natural source such as egg shells is composed of 94 wt. % of calcium carbonate (CaCO3), which can be calcined as calcium oxide (CaO) by the calcinations process. The efficient temperature to produce CaO is 900 °C for 2 hours. The synthesis of nano-HA was done by the mixing the diammonium phosphate (DAP) and calcium hydroxide (Ca(OH)2) and subjected into a microwave for 30 minutes at 1100 W irradiation power. Ball milling process was used for 30 minutes to mix the nano-HA with different compositions of titanium. These were pressed to form pallets by hand hydraulic pump (force=2300 psi). The pallets then were sintered at 1200 °C with the heating rate of 3 °C/min for 2 hours. The pallets were tested by several mechanical testing including hardness, compression strength and wear. From the results, HA-25wt. %Ti composite gave the highest hardness, compression and coefficient of friction for wear test values which were 89.6 Hv, 82.5MPa and 0.76μ respectively. It showed that by adding Ti to nano-HA, the mechanical properties of nano-HA could be enhanced. The microstructure analyses by optical micrograph showed that nano-HA-Ti particles displayed shape likes needle morphology. The particles showed the high tendency to form the agglomerations.

Sustained release of simvastatin from hollow carbonated hydroxyapatite microspheres prepared by aspartic acid and sodium dodecyl sulfate.

Science.gov (United States)

Wang, Ke; Wang, Yinjing; Zhao, Xu; Li, Yi; Yang, Tao; Zhang, Xue; Wu, Xiaoguang

2017-06-01

Hollow carbonated hydroxyapatite (HCHAp) microspheres as simvastatin (SV) sustained-release vehicles were fabricated through a novel and simple one-step biomimetic strategy. Firstly, hollow CaCO 3 microspheres were precipitated through the reaction of CaCl 2 with Na 2 CO 3 in the presence of aspartic acid and sodium dodecyl sulfate. Then, the as-prepared hollow CaCO 3 microspheres were transformed into HCHAp microspheres with a controlled anion-exchange method. The HCHAp microspheres were 3-5μm with a shell thickness of 0.5-1μm and were constructed of short needle nanoparticles. The HCHAp microspheres were then loaded with SV, exhibiting excellent drug-loading capacity and sustained release properties. These results present a new material synthesis strategy for HCHAp microspheres and suggest that the as-prepared HCHAp microspheres are promising for applications in drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

Response of Human Osteoblast to n-HA/PEEK—Quantitative Proteomic Study of Bio-effects of Nano-Hydroxyapatite Composite

Science.gov (United States)

Zhao, Minzhi; Li, Haiyun; Liu, Xiaochen; Wei, Jie; Ji, Jianguo; Yang, Shu; Hu, Zhiyuan; Wei, Shicheng

2016-03-01

Nano-sized hydroxyapatite (n-HA) is considered as a bio-active material, which is often mixed into bone implant material, polyetheretherketone (PEEK). To reveal the global protein expression modulations of osteoblast in response to direct contact with the PEEK composite containing high level (40%) nano-sized hydroxyapatite (n-HA/PEEK) and explain its comprehensive bio-effects, quantitative proteomic analysis was conducted on human osteoblast-like cells MG-63 cultured on n-HA/PEEK in comparison with pure PEEK. Results from quantitative proteomic analysis showed that the most enriched categories in the up-regulated proteins were related to calcium ion processes and associated functions while the most enriched categories in the down-regulated proteins were related to RNA process. This enhanced our understanding to the molecular mechanism of the promotion of the cell adhesion and differentiation with the inhibition of the cell proliferation on n-HA/PEEK composite. It also exhibited that although the calcium ion level of incubate environment hadn’t increased, merely the calcium fixed on the surface of material had influence to intracellular calcium related processes, which was also reflect by the higher intracellular Ca2+ concentration of n-HA/PEEK. This study could lead to more comprehensive cognition to the versatile biocompatibility of composite materials. It further proves that proteomics is useful in new bio-effect discovery.

Response of Human Osteoblast to n-HA/PEEK—Quantitative Proteomic Study of Bio-effects of Nano-Hydroxyapatite Composite

Science.gov (United States)

Zhao, Minzhi; Li, Haiyun; Liu, Xiaochen; Wei, Jie; Ji, Jianguo; Yang, Shu; Hu, Zhiyuan; Wei, Shicheng

2016-01-01

Nano-sized hydroxyapatite (n-HA) is considered as a bio-active material, which is often mixed into bone implant material, polyetheretherketone (PEEK). To reveal the global protein expression modulations of osteoblast in response to direct contact with the PEEK composite containing high level (40%) nano-sized hydroxyapatite (n-HA/PEEK) and explain its comprehensive bio-effects, quantitative proteomic analysis was conducted on human osteoblast-like cells MG-63 cultured on n-HA/PEEK in comparison with pure PEEK. Results from quantitative proteomic analysis showed that the most enriched categories in the up-regulated proteins were related to calcium ion processes and associated functions while the most enriched categories in the down-regulated proteins were related to RNA process. This enhanced our understanding to the molecular mechanism of the promotion of the cell adhesion and differentiation with the inhibition of the cell proliferation on n-HA/PEEK composite. It also exhibited that although the calcium ion level of incubate environment hadn’t increased, merely the calcium fixed on the surface of material had influence to intracellular calcium related processes, which was also reflect by the higher intracellular Ca2+ concentration of n-HA/PEEK. This study could lead to more comprehensive cognition to the versatile biocompatibility of composite materials. It further proves that proteomics is useful in new bio-effect discovery. PMID:26956660

Production of zirconia - hydroxyapatite (Z Ha) by using the co-precipitation method and studies of densification

International Nuclear Information System (INIS)

Silva, Viviane V.; Domingues, Rosana Z.

1997-01-01

Hydroxyapatite (Ha) is one of the materials most bio compatible with human bones and teeth, but its mechanical properties, especially toughness, are insufficient for hard tissue. Recent studies demonstrated that ceramics can be toughened by zirconium particles disperse in them, due to transformation, microcracking, and/or crack diffraction toughening mechanisms. The objective of this study is to characterize zirconia-toughened hydroxy apatite powders prepared by precipitation method by XRD, IR spectroscopy, TEM, TAG, DTA and BET analysis. The density of their ceramics was determined by mercury picnometry method. It was discussed the influence of addition of zirconium in different compositions and phases (Zr O 2 or Zr(OH) 4 ), compacting pressure and sintering temperature on zirconia - hydroxyapatite composites (ZHA). The results show that there is not any kind of reaction or chemical interaction between both phases of the composite materials. (author)

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)

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

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

HA-Coated Implant

DEFF Research Database (Denmark)

Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

2014-01-01

of improving the fixation of implants. Of these, hydroxyapatite (HA) is the most widely used and most extensively investigated. HA is highly osseoconductive, and the positive effect is well documented in both basic and long-term clinical research [1–6]. This chapter describes experimental and clinical studies...

Hydroxyapatite hierarchically nanostructured porous hollow microspheres: rapid, sustainable microwave-hydrothermal synthesis by using creatine phosphate as an organic phosphorus source and application in drug delivery and protein adsorption.

Science.gov (United States)

Qi, Chao; Zhu, Ying-Jie; Lu, Bing-Qiang; Zhao, Xin-Yu; Zhao, Jing; Chen, Feng; Wu, Jin

2013-04-22

Hierarchically nanostructured porous hollow microspheres of hydroxyapatite (HAP) are a promising biomaterial, owing to their excellent biocompatibility and porous hollow structure. Traditionally, synthetic hydroxyapatite is prepared by using an inorganic phosphorus source. Herein, we report a new strategy for the rapid, sustainable synthesis of HAP hierarchically nanostructured porous hollow microspheres by using creatine phosphate disodium salt as an organic phosphorus source in aqueous solution through a microwave-assisted hydrothermal method. The as-obtained products are characterized by powder X-ray diffraction (XRD), Fourier-transform IR (FTIR) spectroscopy, SEM, TEM, Brunauer-Emmett-Teller (BET) nitrogen sorptometry, dynamic light scattering (DLS), and thermogravimetric analysis (TGA). SEM and TEM micrographs show that HAP hierarchically nanostructured porous hollow microspheres consist of HAP nanosheets or nanorods as the building blocks and DLS measurements show that the diameters of HAP hollow microspheres are within the range 0.8-1.5 μm. The specific surface area and average pore size of the HAP porous hollow microspheres are 87.3 m(2) g(-1) and 20.6 nm, respectively. The important role of creatine phosphate disodium salt and the influence of the experimental conditions on the products were systematically investigated. This method is facile, rapid, surfactant-free and environmentally friendly. The as-prepared HAP porous hollow microspheres show a relatively high drug-loading capacity and protein-adsorption ability, as well as sustained drug and protein release, by using ibuprofen as a model drug and hemoglobin (Hb) as a model protein, respectively. These experiments indicate that the as-prepared HAP porous hollow microspheres are promising for applications in biomedical fields, such as drug delivery and protein adsorption. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Study on the antibacterial activity of four kinds of nano-hydroxyapatite composites against Enterococcus faecalis].

Science.gov (United States)

Liu, Yi; Zhou, Rongjing; Wu, Hongkun

2015-06-01

This study aims to compare and determine a kind of nano-hydroxyapatite composite material with good antibacterial efficacy on Enterococcusfaecalis (E. faecalis) in vitro. We investigated the antimicrobial activity of four kinds of nano-hydroxyapatite composites, namely, silver/hydroxyapatite composite nanoparticles (Ag/nHA), yttrium/hydroxyapatite composite nanoparticles (Yi/nHA), cerium/hydroxyapatite composite nanoparticles (Ce/nHA), and hydroxyapatite nanoparticles (nHA), against E. faecalis in vitro using the agar diffusion and broth dilution method by measuring the growth inhibition zone and the minimum inhibitory concentration (MIC), respectively. The agar diffusion test results showed that Ag/nHA displayed an obvious growth inhibition zone, whereas Yi/nHA, Ce/nHA, and nHA showed no influence on E. faecalis. The MIC value of Ag/nHA was 1.0 g.L-1, and the three other materials had no effect on E.faecalis even at the high concentration of 32.0 g.L-1. Ag/nHA display a potential antimicrobial efficacy to planktonic E.faecalis. Whereas, the three other kinds of nano-hydroxyapatite composites (Yi/nHA, Ce/nHA, nHA) show no influence.

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

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)

Adhesive strength of hydroxyl apatite(HA) coating and biomechanics behavior of HA-coated prosthesis:an experimental study

OpenAIRE

Tian-yang ZHANG; Yong-hong DUAN; Shu ZHU; Jin-yu ZHU; Qing-sheng ZHU

2011-01-01

Objective To explore the influence of adhesive strength of hydroxyapatite(HA) coating on the post-implantation stability of HA-coated prosthesis.Methods The adhesive strength and biomechanics behavior of HA coating were studied by histopathological observation,material parameters and biomechanical testing,the titanium(Ti)-coated prosthesis was employed as control.Results Scratch test showed that the adhesive strength of HA coating was significantly lower than that of Ti coating(P < 0.01).Hist...

Characterization, Corrosion Resistance, and Cell Response of High-Velocity Flame-Sprayed HA and HA/TiO2 Coatings on 316L SS

Science.gov (United States)

Singh, Tejinder Pal; Singh, Harpreet; Singh, Hazoor

2012-09-01

The main aim of this study is to evaluate corrosion and biocompatibility behavior of thermal spray hydroxyapatite (HA) and hydroxyapatite/titania bond (HA/TiO2)-coated 316L stainless steel (316L SS). In HA/TiO2 coatings, TiO2 was used as a bond coat between HA top coat and 316L SS substrate. The coatings were characterized by x-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy, and corrosion resistance determined for the uncoated substrate and the two coatings. The biological behavior was investigated by the cell culture studies using osteosarcoma cell line KHOS-NP (R-970-5). The corrosion resistance of the steel was found to increase after the deposition of the HA and HA/TiO2 bond coatings. Both HA, as well as, HA/TiO2 coatings exhibit excellent bond strength of 49 and 47 MPa, respectively. The cell culture studies showed that HA-coated 316L SS specimens appeared more biocompatible than the uncoated and HA/TiO2-coated 316L SS specimens.

Synthesis, structural properties and thermal stability of Mn-doped hydroxyapatite

Science.gov (United States)

Paluszkiewicz, Czesława; Ślósarczyk, Anna; Pijocha, Dawid; Sitarz, Maciej; Bućko, Mirosław; Zima, Aneta; Chróścicka, Anna; Lewandowska-Szumieł, Małgorzata

2010-07-01

Hydroxyapatite (HA) - Ca 10(PO 4) 6(OH) 2 is a basic inorganic model component of hard biological tissues, such as bones and teeth. The significant property of HA is its ability to exchange Ca 2+ ions, which influences crystallinity, physico-chemical and biological properties of modified hydroxyapatite materials. In this work, FTIR, Raman spectroscopy, XRD, SEM and EDS techniques were used to determine thermal stability, chemical and phase composition of Mn containing hydroxyapatite (MnHA). Described methods confirmed thermal decomposition and phase transformation of MnHA to αTCP, βTCP and formation of Mn 3O 4 depending on sintering temperature and manganese content. In vitro biological evaluation of Mn-modified HA ceramics was also performed using human osteoblast cells.

Biomaterials recycling: bioglasses obtained from reuse of hydroxyapatite (HA) bovine bone with term exceeded validity

International Nuclear Information System (INIS)

Silva, A.C.; Santos, S.C.; Braga, F.J.C.; Aparecida, A.H.

2012-01-01

The hydroxyapatite (HA) is a reference bioceramic for bone replacement and regeneration medical practice, becoming one of the most produced and researched bone graft material. Since it is a material for biomedical application, the manufacture and storage of this bioceramic must comply with severe conservation criteria, and its validity date is the lawful major factor for disposal. Materials with the exceeded expiration date are usually discarded and incinerated, resulting in ash, environmental contamination and energy expenditure. This study evaluates the possibility of reuse of bovine HA collected after its validity date as raw material to obtain bioglass, aiming to natural resources saving and environmental emissions mitigation. 45S5 similar compositions were obtained by melting the materials at 1500 ° C, followed by rapid cooling and annealing thermal treatment (500 ° C for 2h), analytical grade chemical reagents were used to set the final composition. The obtained materials were characterized by X-ray diffraction, infrared spectroscopy (FT-IR), and hydrolysis resistance techniques. The results of comparative chemical resistance (Hydrolytic) tests indicate the potential use of the materials developed for bone replacement applications. (author)

In Vitro Degradation of PHBV Scaffolds and nHA/PHBV Composite Scaffolds Containing Hydroxyapatite Nanoparticles for Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

Naznin Sultana

2012-01-01

Full Text Available This paper investigated the long-term in vitro degradation properties of scaffolds based on biodegradable polymers and osteoconductive bioceramic/polymer composite materials for the application of bone tissue engineering. The three-dimensional porous scaffolds were fabricated using emulsion-freezing/freeze-drying technique using poly(hydroxybutyrate-co-hydroxyvalerate (PHBV which is a natural biodegradable and biocompatible polymer. Nanosized hydroxyapatite (nHA particles were successfully incorporated into the PHBV scaffolds to render the scaffolds osteoconductive. The PHBV and nHA/PHBV scaffolds were systematically evaluated using various techniques in terms of mechanical strength, porosity, porous morphology, and in vitro degradation. PHBV and nHA/PHBV scaffolds degraded over time in phosphate-buffered saline at 37°C. PHBV polymer scaffolds exhibited slow molecular weight loss and weight loss in the in vitro physiological environment. Accelerated weight loss was observed in nHA incorporated PHBV composite scaffolds. An increasing trend of crystallinity was observed during the initial period of degradation time. The compressive properties decreased more than 40% after 5-month in vitro degradation. Together with interconnected pores, high porosity, suitable mechanical properties, and slow degradation profile obtained from long-term degradation studies, the PHBV scaffolds and osteoconductive nHA/PHBV composite scaffolds showed promises for bone tissue engineering application.

Preparation and characterization of bio-composite PEEK/nHA

Science.gov (United States)

Jin, Y. S.; Bian, C. C.; Zhang, Z. Q.; Zhao, Y.; Yang, L.

2017-01-01

PEEK/nHA composite material, with excellent mechanical property as polyetheretherketone (PEEK) and biological activity as hydroxyapatite (HA), has attracted wide attention of medical experts and materials science experts. The addition of hydroxyapatite was the decisive factor for biological activity in PEEK/nHA composite. In this paper, acicular nanohydroxyapatite was prepared by chemical precipitation method with Ca(NO3)2, (NH4)2HPO4 as raw material; PEEK/nHA composite was prepared by solution blending and vacuum sintering method. The composite was characterized with FT-IR, XRD, DSC, TG and mechanical property test. Results showed that the composite has good thermal stability and compressive property when the mass ratio of PEEK to nHA is 10:3; and high nHA content can improve the biological activity of the composite, which can meet the basic requirements for bone tissue engineering scaffold.

Comparison between PCL/hydroxyapatite (HA) and PCL/halloysite nanotube (HNT) composite scaffolds prepared by co-extrusion and gas foaming.

Science.gov (United States)

Jing, Xin; Mi, Hao-Yang; Turng, Lih-Sheng

2017-03-01

In this work, three-dimensional poly(caprolactone) (PCL) tissue engineering scaffolds were prepared by co-extrusion and gas foaming. Biocompatible hydroxyapatite (HA) and halloysite nanotubes (HNT) were added to the polymer matrix to enhance the mechanical properties and bioactivity of the composite scaffolds. The effects of HA and HNT on the rheological behavior, microstructure, and mechanical properties of the composite scaffolds were systematically compared. It was found that the HNT improved viscosity more significantly than HA, and reduced the pore size of scaffolds, while the mechanical performance of PCL/HNT scaffolds was higher than PCL/HA scaffolds with the same filler content. Human mesenchymal stem cells (hMSCs) were used as the cell model to compare the biological properties of two composite scaffolds. The results demonstrated that cells could survive on all scaffolds, and showed a more flourishing living state on the composite scaffolds. The cell differentiation for 5% HA and 1% HNT scaffolds were significantly higher than other scaffolds, while the differentiation of 5% HNT scaffolds was lower than that of 1% HNT scaffolds mainly because of the reduced pore size and pore interconnectivity. Therefore, this study suggested that, with proper filler content and control of microstructure through processing, HNT could be a suitable substitute for HA for bone tissue engineering to reduce the cost and improve mechanical performance. Copyright © 2016. Published by Elsevier B.V.

Nanocrystalline hydroxyapatite enriched in selenite and manganese ions: physicochemical and antibacterial properties

Science.gov (United States)

Kolmas, Joanna; Groszyk, Ewa; Piotrowska, Urszula

2015-07-01

In this work, we used the co-precipitation method to synthesize hydroxyapatite (Mn-SeO3-HA) containing both selenium IV (approximately 3.60 wt.%) and manganese II (approximately 0.29 wt.%). Pure hydroxyapatite (HA), hydroxyapatite-containing manganese (II) ions (Mn-HA), and hydroxyapatite-containing selenite ions alone (SeO3-HA), prepared with the same method, were used as reference materials. The structures and physicochemical properties of all the obtained samples were investigated. PXRD studies showed that the obtained materials were homogeneous and consisted of apatite phase. Introducing selenites into the hydroxyapatite crystals considerably affects the size and degree of ordering. Experiments with transmission electron microscopy (TEM) showed that Mn-SeO3-HA crystals are very small, needle-like, and tend to form agglomerates. Fourier transform infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance (ssNMR) were used to analyze the structure of the obtained material. Preliminary microbiological tests showed that the material demonstrated antibacterial activity against Staphylococcus aureus, yet such properties were not confirmed regarding Escherichia coli. PACS codes: 61, 76, 81

Mechanical behaviour of new zirconia-hydroxyapatite ceramic materials

Energy Technology Data Exchange (ETDEWEB)

Delgado, J.A.; Morejon, L. [La Habana Univ. (Cuba). Centro de Biomateriales; Martinez, S. [Barcelona Univ. (Spain). Dept. Cristallografia, Mineralogia; Ginebra, M.P.; Carlsson, N.; Fernandez, E.; Planell, J.A. [Universidad Politecnica de Cataluna, Barcelona (Spain). CREB; Clavaguera-Mora, M.T.; Rodriguez-Viejo, J. [Universitat Autonoma de Barcelona (Spain). Dept. de Fisica

2001-07-01

In this work a new zirconia-hydroxyapatite ceramic material was obtained by uniaxial pressing and sintering in humid environment. The powder X-ray diffraction (XRD) patterns and infrared spectra (FT-IR) showed that the hydroxyapatite (HA) is the only calcium phosphate phase present. The fracture toughness for HA with 20 wt.% of magnesia partially stabilised zirconia (Mg-PSZ) was around 2.5 times higher than those obtained for HA pure, also the highest value of bending strength (160 MPa) was obtained for material reinforced with Mg-PSZ. For the MgPSZ-HA (20%) the fracture mechanism seems to be less transgranular. (orig.)

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)

Superior sealing effect of hydroxyapatite in porous-coated implants

DEFF Research Database (Denmark)

Rahbek, Ole; Kold, Søren; Bendix, Knud

2005-01-01

Migration of wear debris to the periprosthetic bone is a major cause of osteolysis and implant failure. Both closed-pore porous coatings and hydroxyapatite (HA) coatings have been claimed to prevent the migration of wear debris. We investigated whether HA could augment the sealing effect of a por......Migration of wear debris to the periprosthetic bone is a major cause of osteolysis and implant failure. Both closed-pore porous coatings and hydroxyapatite (HA) coatings have been claimed to prevent the migration of wear debris. We investigated whether HA could augment the sealing effect...

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.

Laser treatment of plasma sprayed HA coatings

NARCIS (Netherlands)

Khor, KA; Vreeling, A; Dong, ZL; Cheang, P

1999-01-01

Laser treatment was conducted on plasma sprayed hydroxyapatite (HA) coatings using a Nd-YAG pulse laser. Various laser parameters were investigated. The results showed that the HA surface melted when an energy level of greater than or equal to 2 J and a spot size of 2 mm was employed during

Crystallization of modified hydroxyapatite on titanium implants

International Nuclear Information System (INIS)

Golovanova, O A; Izmailov, R R; Zaits, A V; Ghyngazov, S A

2016-01-01

Carbonated-hydroxyapatite (CHA) and Si-hydroxyapatite (Si-HA) precipitation have been synthesized from the model bioliquid solutions (synovial fluid and SBF). It is found that all the samples synthesized from the model solutions are single-phase and represent hydroxyapatite. The crystallization of the modified hydroxyapatite on alloys of different composition, roughness and subjected to different treatment techniques was investigated. Irradiation of the titanium substrates with the deposited biomimetic coating can facilitate further growth of the crystal and regeneration of the surface. (paper)

Effect of calcinations temperature on the luminescence intensity and fluorescent lifetime of Tb3+-doped hydroxyapatite (Tb-HA nanocrystallines

Directory of Open Access Journals (Sweden)

Hairong Yin

2017-06-01

Full Text Available Hydroxyapatite luminescent nanocrystallines doped with 6 mol.% Tb3+ (Tb-HA were prepared via chemical deposition method and calcined at different temperature, and the effects of calcinations temperature on the luminescence intensity and fluorescent lifetime were studied. TEM image of Tb-HA revealed that the shape of nanocrystallines changed from needle-like to short rod-like and sphere-like with the increase of calcinations temperature; while the particles sizes decreased from 190 nm to 110 nm. The crystallinity degree increased. The typical emission peaks attributed to Tb3+ ions were observed in emission spectra of 6 mol.% Tb-HA under 378 nm excitation. The luminescent intensity of Tb-HA, which showed the fluorescence quenching, firstly enhanced and then decreased at 700 °C; while the fluorescent lifetime increased firstly and then decreased after 600 °C. Furthermore, the ratio of intensity between 545 nm and 490 nm corresponding to electric-dipole and magnetic-dipole transition (IR: IO increases firstly and then decreases, which revealed that the proportion of substitute type and site of Ca2+ ions by Tb3+ ions were helpful to realize the substitute process and functional structure design.

Hydroxyapatite nucleated and grown on nano titania particles enhances recruitment of Escherichia coli for subsequent photocatalytic elimination

International Nuclear Information System (INIS)

Huang, Jing; Liu, Yi; Liu, Yuxin; Li, Hua

2015-01-01

Titania-hydroxyapatite (HA) nanocomposites were fabricated by wet chemical synthesis approach. HA exhibited crystallographic orientation of nucleation on nano titania particle, forming the composite particles with titania being partially enwrapped with HA. Microstructural characterization by high resolution transmission electron microscopy revealed coherent interfacial bond of (110) and (222) planes of HA crystal with (101) plane of anatase. The HA layer promoted significantly recruitment of Escherichia coli bacteria onto the titania-based particles for subsequent photocatalytic killing. Less extent of enwrapping of HA on titania particle, as accomplished by increasing the aging time of HA suspension, gave rise to better capability of photocatalytic degradation of methylene blue and sterilization of the bacteria. The novel HA-enwrapped titania powder shows great potential for environmental applications. - Highlights: • Titania-hydroxyapatite nanocomposite powder was fabricated with cladding structure. • Hydroxyapatite nucleated and grew on titania particle with preferred orientation. • Hydroxyapatite layer promotes recruitment of Escherichia coli onto titania-based particles. • The titania-hydroxyapatite particles show excellent antibacterial performances. • The nanocomposite powder exhibits excellent photocatalytic performances

Hydroxyapatite nucleated and grown on nano titania particles enhances recruitment of Escherichia coli for subsequent photocatalytic elimination

Energy Technology Data Exchange (ETDEWEB)

Huang, Jing; Liu, Yi; Liu, Yuxin; Li, Hua, E-mail: lihua@nimte.ac.cn

2015-02-01

Titania-hydroxyapatite (HA) nanocomposites were fabricated by wet chemical synthesis approach. HA exhibited crystallographic orientation of nucleation on nano titania particle, forming the composite particles with titania being partially enwrapped with HA. Microstructural characterization by high resolution transmission electron microscopy revealed coherent interfacial bond of (110) and (222) planes of HA crystal with (101) plane of anatase. The HA layer promoted significantly recruitment of Escherichia coli bacteria onto the titania-based particles for subsequent photocatalytic killing. Less extent of enwrapping of HA on titania particle, as accomplished by increasing the aging time of HA suspension, gave rise to better capability of photocatalytic degradation of methylene blue and sterilization of the bacteria. The novel HA-enwrapped titania powder shows great potential for environmental applications. - Highlights: • Titania-hydroxyapatite nanocomposite powder was fabricated with cladding structure. • Hydroxyapatite nucleated and grew on titania particle with preferred orientation. • Hydroxyapatite layer promotes recruitment of Escherichia coli onto titania-based particles. • The titania-hydroxyapatite particles show excellent antibacterial performances. • The nanocomposite powder exhibits excellent photocatalytic performances.

The Effect of Titanium Dioxide (TiO2) Nanoparticles on Hydroxyapatite (HA)/TiO2 Composite Coating Fabricated by Electrophoretic Deposition (EPD)

Science.gov (United States)

Amirnejad, M.; Afshar, A.; Salehi, S.

2018-05-01

Composite coatings of Hydroxyapatite (HA) with ceramics, polymers and metals are used to modify the surface structure of implants. In this research, HA/TiO2 composite coating was fabricated by electrophoretic deposition (EPD) on 316 stainless steel substrate. HA/TiO2 composite coatings with 5, 10 and 20 wt.% of TiO2, deposited at 40 V and 90 s as an optimum condition. The samples coated at this condition led to an adherent, continuous and crack-free coating. The influence of TiO2 content was studied by performing different characterization methods such as scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), corrosion resistance in simulated body fluid (SBF), coating's dissolution rate in physiological solution and bond strength to the substrate. The results showed that the higher amount of TiO2 in the composite coating led to increase in bond strength of coating to stainless steel substrate from 3 MPa for HA coating to 5.5 MPa for HA-20 wt.% TiO2 composite coating. In addition, it caused to reduction of corrosion current density of samples in the SBF solution from 18.92 μA/cm2 for HA coating to 6.35 μA/cm2 for HA-20 wt.% TiO2 composite coating.

The Effect of Titanium Dioxide (TiO2) Nanoparticles on Hydroxyapatite (HA)/TiO2 Composite Coating Fabricated by Electrophoretic Deposition (EPD)

Science.gov (United States)

Amirnejad, M.; Afshar, A.; Salehi, S.

2018-04-01

Composite coatings of Hydroxyapatite (HA) with ceramics, polymers and metals are used to modify the surface structure of implants. In this research, HA/TiO2 composite coating was fabricated by electrophoretic deposition (EPD) on 316 stainless steel substrate. HA/TiO2 composite coatings with 5, 10 and 20 wt.% of TiO2, deposited at 40 V and 90 s as an optimum condition. The samples coated at this condition led to an adherent, continuous and crack-free coating. The influence of TiO2 content was studied by performing different characterization methods such as scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), corrosion resistance in simulated body fluid (SBF), coating's dissolution rate in physiological solution and bond strength to the substrate. The results showed that the higher amount of TiO2 in the composite coating led to increase in bond strength of coating to stainless steel substrate from 3 MPa for HA coating to 5.5 MPa for HA-20 wt.% TiO2 composite coating. In addition, it caused to reduction of corrosion current density of samples in the SBF solution from 18.92 μA/cm2 for HA coating to 6.35 μA/cm2 for HA-20 wt.% TiO2 composite coating.

Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

Science.gov (United States)

Shi, Xinchang

2017-01-01

Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and energy dispersive spectrometer (EDS). The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1) Zn2+ absorbed on the surface of HA crystal and (2) Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM) results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization. PMID:29159178

Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

Directory of Open Access Journals (Sweden)

Yi Li

2017-01-01

Full Text Available Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, and energy dispersive spectrometer (EDS. The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1 Zn2+ absorbed on the surface of HA crystal and (2 Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization.

Post-translational modification of osteopontin: Effects on in vitro hydroxyapatite formation and growth

DEFF Research Database (Denmark)

Boskey, Adele L.; Christensen, Brian Søndergaard; Taleb, Hayat

2012-01-01

The manuscript tests the hypothesis that posttranslational modification of the SIBLING family of proteins in general and osteopontin in particular modify the abilities of these proteins to regulate in vitro hydroxyapatite (HA) formation. Osteopontin has diverse effects on hydroxyapatite (HA...

Determination of Microstructural Parameters of Nanocrystalline Hydroxyapatite Prepared by Mechanical Alloying Method

Science.gov (United States)

Joughehdoust, Sedigheh; Manafi, Sahebali

2011-12-01

Hydroxyapatite [HA, Ca10(PO4)6(OH)2] is chemically similar to the mineral component of bones and hard tissues. HA can support bone ingrowth and osseointegration when used in orthopaedic, dental and maxillofacial applications. In this research, HA nanostructure was synthesized by mechanical alloying method. Phase development, particle size and morphology of HA were investigated by X-ray diffraction (XRD) pattern, zetasizer instrument, scanning electron microscopy (SEM), respectively. XRD pattern has been used to determination of the microstructural parameters (crystallite size, lattice parameters and crystallinity percent) by Williamson-Hall equation, Nelson-Riley method and calculating the areas under the peaks, respectively. The crystallite size and particle size of HA powders were in nanometric scales. SEM images showed that some parts of HA particles have agglomerates. The ratio of lattice parameters of synthetic hydroxyapatite (c/a = 0.73) was determined in this study is the same as natural hydroxyapatite structure.

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.

Hydroxyapatite/polylactide biphasic combination scaffold loaded with dexamethasone for bone regeneration.

Science.gov (United States)

Son, Jun-Sik; Kim, Su-Gwan; Oh, Ji-Su; Appleford, Mark; Oh, Sunho; Ong, Joo L; Lee, Kyu-Bok

2011-12-15

This study presents a novel design of a ceramic/polymer biphasic combination scaffold that mimics natural bone structures and is used as a bone graft substitute. To mimic the natural bone structures, the outside cortical-like shells were composed of porous hydroxyapatite (HA) with a hollow interior using a polymeric template-coating technique; the inner trabecular-like core consisted of porous poly(D,L-lactic acid) (PLA) that was loaded with dexamethasone (DEX) and was directly produced using a particle leaching/gas forming technique to create the inner diameter of the HA scaffold. It was observed that the HA and PLA parts of the fabricated HA/PLA biphasic scaffold contained open and interconnected pore structures, and the boundary between both parts was tightly connected without any gaps. It was found that the structure of the combination scaffold was analogous to that of natural bone based on micro-computed tomography analysis. Additionally, the dense, uniform apatite layer was formed on the surface of the HA/PLA biphasic scaffold through a biomimetic process, and DEX was successfully released from the PLA of the biphasic scaffold over a 1-month period. This release caused human embryonic palatal mesenchyme cells to proliferate, differentiate, produce ECM, and form tissue in vitro. Therefore, it was concluded that this functionally graded scaffold is similar to natural bone and represents a potential bone-substitute material. Copyright © 2011 Wiley Periodicals, Inc.

New Coll–HA/BT composite materials for hard tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zanfir, Andrei Vlad [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, “Politehnica” University of Bucharest, 1-7 Gh. Polizu Street, RO-011061 Bucharest (Romania); Voicu, Georgeta, E-mail: getav2001@yahoo.co.uk [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, “Politehnica” University of Bucharest, 1-7 Gh. Polizu Street, RO-011061 Bucharest (Romania); Busuioc, Cristina; Jinga, Sorin Ion [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, “Politehnica” University of Bucharest, 1-7 Gh. Polizu Street, RO-011061 Bucharest (Romania); Albu, Madalina Georgiana [Department of Collagen, Branch of Leather and Footwear Research, National Institute of Research and Development for Textile and Leather, 93 I. Minulescu Street, RO-031215 Bucharest (Romania); Iordache, Florin [Department of Fetal and Adult Stem Cell Therapy, “Nicolae Simionescu” Institute of Cellular Biology and Pathology of Romanian Academy, 8 B.P. Hasdeu Street, RO-050568 Bucharest (Romania)

2016-05-01

The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen–hydroxyapatite/barium titanate (Coll–HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol–gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll–HA and Coll–HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll–HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT. - Highlights: • Collagen–hydroxyapatite/barium titanate composite materials were synthesized. • Barium titanate was produced by combining the sol–gel and hydrothermal methods. • The in vitro tests highlight excellent osteoinductive properties for all samples.

New Coll–HA/BT composite materials for hard tissue engineering

International Nuclear Information System (INIS)

Zanfir, Andrei Vlad; Voicu, Georgeta; Busuioc, Cristina; Jinga, Sorin Ion; Albu, Madalina Georgiana; Iordache, Florin

2016-01-01

The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen–hydroxyapatite/barium titanate (Coll–HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol–gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll–HA and Coll–HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll–HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT. - Highlights: • Collagen–hydroxyapatite/barium titanate composite materials were synthesized. • Barium titanate was produced by combining the sol–gel and hydrothermal methods. • The in vitro tests highlight excellent osteoinductive properties for all samples.

Near net-shape fabrication of hydroxyapatite glass composites

NARCIS (Netherlands)

Zhu, Q.; With, de G.; Dortmans, L.; Feenstra, F.

2004-01-01

Near net-shape fabrication of hydroxyapatite (HA) glass composites has been attempted by infiltrating a glass into porous HA performs. Main efforts were put to develop glasses that are chemically compatible with HA at elevated temperatures. After extensive investigations in the phosphate and

Intercalated chitosan/hydroxyapatite nanocomposites: Promising materials for bone tissue engineering applications.

Science.gov (United States)

Nazeer, Muhammad Anwaar; Yilgör, Emel; Yilgör, Iskender

2017-11-01

Preparation and characterization of chitosan/hydroxyapatite (CS/HA) nanocomposites displaying an intercalated structure is reported. Hydroxyapatite was synthesized through sol-gel process. Formic acid was introduced as a new solvent to obtain stable dispersions of nano-sized HA particles in polymer solution. CS/HA dispersions with HA contents of 5, 10 and 20% by weight were prepared. Self-assembling of HA nanoparticles during the drying of the solvent cast films led to the formation of homogeneous CS/HA nanocomposites. Composite films were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-rays (EDX) analysis, Fourier transform infrared (FTIR) spectroscopy, X-rays diffraction (XRD) analysis and thermogravimetric analysis (TGA). SEM and AFM confirmed the presence of uniformly distributed HA nanoparticles on the chitosan matrix surface. XRD patterns and cross-sectional SEM images showed the formation of layered nanocomposites. Complete degradation of chitosan matrix in TGA experiments, led to the formation of nanoporous 3D scaffolds containing hydroxyapatite, β-tricalcium phosphate and calcium pyrophosphate. CS/HA composites can be considered as promising materials for bone tissue engineering applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of hydroxyapatite bone cement for controlled drug ...

Indian Academy of Sciences (India)

The purpose of this work was to study the preparation and characterization of drug–hydroxyapatite cement. The hydroxyapatite (HA) cement has been synthesized by using tricalcium phosphate, calcium carbonate and dicalcium phosphate anhydrous with sodium hydrogen phosphate as liquid phase. The effect of added ...

Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

International Nuclear Information System (INIS)

Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

2013-01-01

The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO 2 anatase, TiO 2 rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I corr than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO 2 , HA, and Ca 5 (PO 4 ) 2 SiO 4 . • Polarization resistance of the coating was increased by Si substitution in HA

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.

Comparative study of hydroxyapatite from eggshells and synthetic hydroxyapatite for bone regeneration.

Science.gov (United States)

Lee, Sang-Woon; Kim, Seong-Gon; Balázsi, Csaba; Chae, Weon-Sik; Lee, Hee-Ok

2012-03-01

The objective of this study was to evaluate the physical properties of synthetic hydroxyapatite (sHA) and hydroxyapatite from eggshells (eHA) by Fourier-transform infrared (FT-IR) and x-ray diffraction (XRD) and to compare the regenerative ability of the bone using sHA and eHA in a rabbit calvarial defect model. FT-IR and XRD were used to compare the physical properties of sHA and eHA. sHA was purchased from Sigma, and eHA was kindly donated from the Hungarian academy of science. Sixteen New Zealand white rabbits were used for the animal study. After the formation of a bilateral parietal bony defect (diameter 8.0 mm), either sHA or eHA was grafted into the defect. The defect in the control was left unfilled. Bone regeneration was evaluated by histomorphometry at 4 and 8 weeks after the operation. The peak broadening of the XRD experiments were in agreement with scanning electron microscope observation; the sHA had a smaller granule size than the eHA. The eHA had impurities phases of CaO (International Center for Diffraction Data (ICDD) 075-0264) and Ca(OH)(2) (ICDD 072-0156). Total new bone was 17.11 ± 10.24% in the control group, 28.81 ± 12.63% in sHA group, and 25.68 ± 10.89% in eHA group at 4 weeks after the operation. The difference was not statistically significant (P > .05). Total new bone at 8 weeks after the operation was 27.50 ± 10.89% in the control group, 38.62 ± 17.42% in sHA group, and 41.99 ± 8.44% in the eHA group. When comparing the sHA group to the control group, the difference was not statistically significant (P > .05). However, the eHA group was significantly different from the control group (P = .038). When comparing the eHA group to the sHA group, the difference was not statistically significant (P > .05). Both types of HA showed higher bone formation than the unfilled control. However, eHA had significantly higher bone formation than the unfilled control at 8 weeks after operation. Copyright © 2012 Elsevier Inc. All rights reserved.

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)

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)

In situ deposition of hydroxyapatite on graphene nanosheets

International Nuclear Information System (INIS)

Neelgund, Gururaj M.; Oki, Aderemi; Luo, Zhiping

2013-01-01

Graphical abstract: A facile chemical precipitation method is reported for effective in situ deposition of hydroxyapatite on graphene nanosheets. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. Display Omitted Highlights: ► It is a facile and effective method for deposition of HA on GR nanosheets. ► It avoids the use of harmful reducing agents like hydrazine, NaBH 4 etc. ► GR nanosheets were produced using bio-compatible, ethylenediamine. ► The graphitic structure of synthesized GR nanosheets was high ordered. ► The ratio of Ca to P in HA was 1.64, which is close to ratio in natural bone. -- Abstract: Graphene nanosheets were effectively functionalized by in situ deposition of hydroxyapatite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure.

In situ deposition of hydroxyapatite on graphene nanosheets

Energy Technology Data Exchange (ETDEWEB)

Neelgund, Gururaj M. [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Oki, Aderemi, E-mail: aroki@pvamu.edu [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Luo, Zhiping [Microscopy and Imaging Center and Materials Science and Engineering Program, Texas A and M University, College Station, TX 77843 (United States)

2013-02-15

Graphical abstract: A facile chemical precipitation method is reported for effective in situ deposition of hydroxyapatite on graphene nanosheets. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. Display Omitted Highlights: ► It is a facile and effective method for deposition of HA on GR nanosheets. ► It avoids the use of harmful reducing agents like hydrazine, NaBH{sub 4} etc. ► GR nanosheets were produced using bio-compatible, ethylenediamine. ► The graphitic structure of synthesized GR nanosheets was high ordered. ► The ratio of Ca to P in HA was 1.64, which is close to ratio in natural bone. -- Abstract: Graphene nanosheets were effectively functionalized by in situ deposition of hydroxyapatite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure.

Biomedical potential of chitosan/HA and chitosan/β-1,3-glucan/HA biomaterials as scaffolds for bone regeneration — A comparative study

Energy Technology Data Exchange (ETDEWEB)

Przekora, Agata, E-mail: agata.przekora@umlub.pl [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodzki 1, 20-093 Lublin (Poland); Palka, Krzysztof [Department of Materials Engineering, Lublin University of Technology, Nadbystrzycka 36, 20-618 Lublin (Poland); Ginalska, Grazyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodzki 1, 20-093 Lublin (Poland)

2016-01-01

The aim of this work was to compare biomedical potential of chitosan/hydroxyapatite (chit/HA) and novel chitosan/β-1,3-glucan/hydroxyapatite (chit/glu/HA) materials as scaffolds for bone regeneration via characterization of their biocompatibility, porosity, mechanical properties, and water uptake behaviour. Biocompatibility of the scaffolds was assessed in direct-contact with the materials using normal human foetal osteoblast cell line. Cytotoxicity and osteoblast proliferation rate were evaluated. Porosity was assessed using computed microtomography analysis and mechanical properties were determined by compression testing. Obtained results demonstrated that chit/HA scaffold possessed significantly better mechanical properties (compressive strength: 1.23 MPa, Young's modulus: 0.46 MPa) than chit/glu/HA material (compressive strength: 0.26 MPa, Young's modulus: 0.25 MPa). However, addition of bacterial β-1,3-glucan to the chit/HA scaffold improved its flexibility and porosity. Moreover, chit/glu/HA scaffold revealed significantly higher water uptake capability (52.6% after 24 h of soaking) compared to the chit/HA (30.7%) and thus can serve as a very good drug delivery carrier. Chit/glu/HA scaffold was also more favourable to osteoblast survival (near 100% viability after 24-h culture), proliferation, and spreading compared to the chit/HA (63% viability). The chit/glu/HA possesses better biomedical potential than chit/HA scaffold. Nevertheless, poor mechanical properties of the chit/glu/HA limit its application to non-load bearing implantation area. - Highlights: • Chitosan/HA and chit/β-1,3-glucan/HA scaffolds for bone regeneration were compared. • Chit/HA significantly reduced osteoblast viability to 63% compared to chit/glu/HA. • Unlike chit/HA, chit/glu/HA favoured cell adhesion, spreading, and proliferation. • Chit/HA had better compressive strength and Young's modulus than chit/glu/HA. • Chit/glu/HA revealed significantly higher

Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation

Energy Technology Data Exchange (ETDEWEB)

Chen, Wei [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Tian, Bo [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Lei, Yong; Ke, Qin-Fei [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Zhu, Zhen-An, E-mail: zhuzhenan2006@126.com [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Guo, Ya-Ping, E-mail: ypguo@shnu.edu.cn [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China)

2016-10-01

Hydroxyapatite (HA) crystals exhibit rod-like shape with c-axis orientation and plate-like shape with a(b)-axis orientation in vertebrate bones and tooth enamel surfaces, respectively. Herein, we report the synthesis of HA coatings with the oriented nanorod arrays (RHACs) and HA coatings with oriented nanoplate arrays (PHACs) by using bioglass coatings as sacrificial templates. After soaking in simulated body fluid (SBF) at 120 °C, the bioglass coatings are hydrothermally converted into the HA coatings via a dissolution-precipitation reaction. If the Ca/P ratios in SBF are 2.50 and 1.25, the HA crystals on the coatings are oriented nanorod arrays and oriented nanoplate arrays, respectively. Moreover, the bioglass coatings are treated with SBF at 37 °C, plate-like HA coatings with a low crystallinity (SHACs) are prepared. As compared with the Ti6Al4V and SHACs, the human bone marrow stromal cells (hBMSCs) on the RHACs and PHACs have better cell adhesion, spreading, proliferation and osteogenic differentiation because of their moderately hydrophilic surfaces and similar chemical composition, morphology and crystal orientation to human hard tissues. Notably, the morphologies of HA crystals have no obvious effects on cytocompatibility and osteogenic differentiation. Hence, the HA coatings with oriented nanoplate arrays or oriented nanorod arrays have a great potential for orthopedic applications. - Highlights: • We prepare hydroxyapatite coatings with oriented nanoplate and nanorod arrays. • Hydroxyapatite coatings are in situ converted from bioglass coatings. • Hydroxyapatite coatings have good cytocompatibility and osteogenic differentiation. • Oriented hydroxyapatite coatings are used for orthopedic implants.

Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation

International Nuclear Information System (INIS)

Chen, Wei; Tian, Bo; Lei, Yong; Ke, Qin-Fei; Zhu, Zhen-An; Guo, Ya-Ping

2016-01-01

Hydroxyapatite (HA) crystals exhibit rod-like shape with c-axis orientation and plate-like shape with a(b)-axis orientation in vertebrate bones and tooth enamel surfaces, respectively. Herein, we report the synthesis of HA coatings with the oriented nanorod arrays (RHACs) and HA coatings with oriented nanoplate arrays (PHACs) by using bioglass coatings as sacrificial templates. After soaking in simulated body fluid (SBF) at 120 °C, the bioglass coatings are hydrothermally converted into the HA coatings via a dissolution-precipitation reaction. If the Ca/P ratios in SBF are 2.50 and 1.25, the HA crystals on the coatings are oriented nanorod arrays and oriented nanoplate arrays, respectively. Moreover, the bioglass coatings are treated with SBF at 37 °C, plate-like HA coatings with a low crystallinity (SHACs) are prepared. As compared with the Ti6Al4V and SHACs, the human bone marrow stromal cells (hBMSCs) on the RHACs and PHACs have better cell adhesion, spreading, proliferation and osteogenic differentiation because of their moderately hydrophilic surfaces and similar chemical composition, morphology and crystal orientation to human hard tissues. Notably, the morphologies of HA crystals have no obvious effects on cytocompatibility and osteogenic differentiation. Hence, the HA coatings with oriented nanoplate arrays or oriented nanorod arrays have a great potential for orthopedic applications. - Highlights: • We prepare hydroxyapatite coatings with oriented nanoplate and nanorod arrays. • Hydroxyapatite coatings are in situ converted from bioglass coatings. • Hydroxyapatite coatings have good cytocompatibility and osteogenic differentiation. • Oriented hydroxyapatite coatings are used for orthopedic implants.

Cell death induced by hydroxyapatite on L929 fibroblast cells.

Science.gov (United States)

Inayat-Hussain, S H; Rajab, N F; Roslie, H; Hussin, A A; Ali, A M; Annuar, B O

2004-05-01

Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.

Preparation and properties of in-situ growth of carbon nanotubes reinforced hydroxyapatite coating for carbon/carbon composites

Energy Technology Data Exchange (ETDEWEB)

Liu, Shoujie, E-mail: jlliushoujie@126.com; Li, Hejun, E-mail: lihejun@nwpu.edu.cn; Su, Yangyang, E-mail: suyangyang@mail.nwpu.edu.cn; Guo, Qian, E-mail: 1729299905@163.com; Zhang, Leilei, E-mail: zhangleilei@nwpu.edu.cn

2017-01-01

Carbon nanotubes (CNTs) possess excellent mechanical properties for their role playing in reinforcement as imparting strength to brittle hydroxyapatite (HA) bioceramic coating. However, there are few reports relating to the in-situ grown carbon nanotubes reinforced hydroxyapatite (CNTs-HA) coating. Here we demonstrate the potential application in reinforcing biomaterials by an attempt to use in-situ grown of CNTs strengthen HA coating, using a combined method composited of injection chemical vapor deposition (ICVD) and pulsed electrodeposition. The microstructure, phases and chemical compositions of CNTs-HA coatings were characterized by various advanced methods. The scanning electron microscopy (SEM) images indicated that CNTs-HA coatings avoided the inhomogeneous dispersion of CNTs inside HA coating. The result show that the interfacial shear strength between CNTs-HA coating and the C/C composite matrix reaches to 12.86 ± 1.43 MPa. Potenitodynamic polarization and electrochemical impedance spectroscopy (EIS) studies show that the content of CNTs affects the corrosion resistance of CNTs-HA coating. Cell culturing and simulated body fluid test elicit the biocompatibility with living cells and bioactivity of CNTs-HA coatings, respectively. - Highlights: • A novel bioceramic composite coating of hydroxyapatite reinforced with in-situ grown carbon nanotubes was fabricated. • The doping of carbon nanotubes had almost no impact on the biocompatibility of hydroxyapatite coatings. • The doping of carbon nanotubes improved corrosion resistance of hydroxyapatite coatings in simulated human body solution.

Formation of nano-hydroxyapatite crystal in situ in chitosan-pectin polyelectrolyte complex network

International Nuclear Information System (INIS)

Li Junjie; Zhu Dunwan; Yin Jianwei; Liu Yuxi; Yao Fanglian; Yao Kangde

2010-01-01

Hydroxyapatite (HA)/polysaccharide composites have been widely used in bone tissue engineering due to their chemical similarity to natural bone. Polymer matrix-mediated synthesis of nano-hydroxyapatite is one of the simplest models for biomimetic. In this article, the nano-hydroxyapatite/chitosan-pectin (nHCP) composites were prepared through in situ mineralization of hydroxyapatite in chitosan-pectin polyelectrolyte complex (PEC) network. The formation processes of nHCP were investigated by X-ray diffraction (XRD) analysis. The interactions between nHA crystal and chitosan-pectin PEC networks were studied using Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). The morphology and structure of nHA crystal were characterized by XRD and Transmission Electron Microscope (TEM). Results suggested that the interfacial interactions between nano-hydroxyapatite crystal and chitosan-pectin PEC network assist the site specific nucleation and growth of nHA nanoparticles. The nHA crystals grow along the c-axis. In this process, pH value is the main factor to control the nucleation and growth of nHA crystal in chitosan-pectin PEC networks, because both the interactions' strength between nHA crystal and chitosan-pectin and diffusion rate of inorganic ions depend on the pH value of the reaction system. Apart from the pH value, the chitosan/pectin ratio and [Ca 2+ ] also take important effects on the formation of nHA crystal. An effective way to control the size of nHA crystal is to adjust the content of pectin and [Ca 2+ ]. It is interesting that the Zeta potential of nHCP composites is about - 30 mV when the chitosan/pectin ratio ≤ 1:1, and the dispersion solution of nHCP composites has higher stability, which provides the possibility to prepare 3D porous scaffolds with nHCP for bone tissue engineering.

Formation of nano-hydroxyapatite crystal in situ in chitosan-pectin polyelectrolyte complex network

Energy Technology Data Exchange (ETDEWEB)

Li Junjie [Department of Polymer Science and Key Laboratory of Systems Bioengineering of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 (China); Research Institute of Polymeric Materials, Tianjin University, Tianjin, 300072 (China); Zhu Dunwan [Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, 300072 (China); Yin Jianwei; Liu Yuxi [Department of Polymer Science and Key Laboratory of Systems Bioengineering of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 (China); Yao Fanglian, E-mail: yaofanglian@tju.edu.cn [Department of Polymer Science and Key Laboratory of Systems Bioengineering of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 (China); Yao Kangde [Research Institute of Polymeric Materials, Tianjin University, Tianjin, 300072 (China)

2010-07-20

Hydroxyapatite (HA)/polysaccharide composites have been widely used in bone tissue engineering due to their chemical similarity to natural bone. Polymer matrix-mediated synthesis of nano-hydroxyapatite is one of the simplest models for biomimetic. In this article, the nano-hydroxyapatite/chitosan-pectin (nHCP) composites were prepared through in situ mineralization of hydroxyapatite in chitosan-pectin polyelectrolyte complex (PEC) network. The formation processes of nHCP were investigated by X-ray diffraction (XRD) analysis. The interactions between nHA crystal and chitosan-pectin PEC networks were studied using Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). The morphology and structure of nHA crystal were characterized by XRD and Transmission Electron Microscope (TEM). Results suggested that the interfacial interactions between nano-hydroxyapatite crystal and chitosan-pectin PEC network assist the site specific nucleation and growth of nHA nanoparticles. The nHA crystals grow along the c-axis. In this process, pH value is the main factor to control the nucleation and growth of nHA crystal in chitosan-pectin PEC networks, because both the interactions' strength between nHA crystal and chitosan-pectin and diffusion rate of inorganic ions depend on the pH value of the reaction system. Apart from the pH value, the chitosan/pectin ratio and [Ca{sup 2+}] also take important effects on the formation of nHA crystal. An effective way to control the size of nHA crystal is to adjust the content of pectin and [Ca{sup 2+}]. It is interesting that the Zeta potential of nHCP composites is about - 30 mV when the chitosan/pectin ratio {<=} 1:1, and the dispersion solution of nHCP composites has higher stability, which provides the possibility to prepare 3D porous scaffolds with nHCP for bone tissue engineering.

Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Jeong, Yong-Hoon [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States); Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States)

2013-11-01

The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO{sub 2} anatase, TiO{sub 2} rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I{sub corr} than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO{sub 2}, HA, and Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4}. • Polarization resistance of the coating was increased by Si substitution in HA.

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

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.

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

Influence of preparation method on hydroxyapatite porous scaffolds

Indian Academy of Sciences (India)

Administrator

Hydroxyapatite (HA) is extensively used in medical applications as an artificial bone because of its similarity to ... system, have been applied to fabricate HA porous scaffolds. In this work .... ceramic structured by the colloidal processing was.

Sorption of zinc on synthetic hydroxyapatite from aqueous solution

International Nuclear Information System (INIS)

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

2014-01-01

The sorption of Zn 2+ on synthetic hydroxyapatite was investigated using a batch method and radiotracer technique. This work was aimed to study influence of the contact time, effect of pH and different concentration of Zn 2+ ions in the solution. The percentage of zinc adsorption on HA1 and HA2 was more than 96 % during 1 h for initial Zn 2+ concentration of 1·10 -4 .5·10 -4 and 1·10 -3 mol·dm -3 . The equilibrium time of 2 h was chosen for further experiments. The sorption of zinc on hydroxyapatite was pH independent ranging from 4.5 to 6.5 as a result of buffering properties of hydroxyapatite. The experimental data for adsorption of zinc have been interpreted in the term of Langmuir isotherm and the value of maximum adsorption capacity of zinc on a commercial hydroxyapatite and hydroxyapatite prepared by wet precipitation process was calculated to be 0.437 mmol·g -1 and 0.605 mmol·g -1 , respectively. (authors)

Synthesis of dense nano cobalt-hydroxyapatite by modified electroless deposition technique

Energy Technology Data Exchange (ETDEWEB)

Mohd Zaheruddin, K., E-mail: zaheruddin@unimap.edu.my; Rahmat, A., E-mail: azmirahmat@unimap.edu.my; Shamsul, J. B., E-mail: sbaharin@unimap.edu.my; Mohd Nazree, B. D., E-mail: nazree@unimap.edu.my; Aimi Noorliyana, H., E-mail: aimiliyana@unimap.edu.my [School of Materials Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi Universiti Malaysia Perlis, Taman Muhibbah, Jejawi 02600 Arau Perlis (Malaysia)

2016-07-19

Cobalt-hydroxyapatite (Co-HA) composites was successfully prepared by simple electroless deposition process of Co on the surface of hydroxyapatite (HA) particles. Co deposition was carried out in an alkaline bath with sodium hypophosphite as a reducing agent. The electroless process was carried out without sensitization and activation steps. The deposition of Co onto HA was characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The Co-HA composite powder was compacted and sintered at 1250°C. The Co particles were homogeneously dispersed in the HA matrix after sintering and the mechanical properties of composites was enhanced to 100 % with 3 % wt Co and gradually decreased at higher Co content.

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.

Suspension thermal spraying of hydroxyapatite: Microstructure and in vitro behaviour

Energy Technology Data Exchange (ETDEWEB)

Bolelli, Giovanni, E-mail: giovanni.bolelli@unimore.it [Department of Engineering “Enzo Ferrari”, Università di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena, MO (Italy); Bellucci, Devis; Cannillo, Valeria; Lusvarghi, Luca; Sola, Antonella [Department of Engineering “Enzo Ferrari”, Università di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena, MO (Italy); Stiegler, Nico; Müller, Philipp; Killinger, Andreas; Gadow, Rainer [Institute for Manufacturing Technologies of Ceramic Components and Composites (IMTCCC), Universität Stuttgart, Allmandring 7b, 70569 Stuttgart (Germany); Altomare, Lina; De Nardo, Luigi [Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano (Italy)

2014-01-01

In cementless fixation of metallic prostheses, bony ingrowth onto the implant surface is often promoted by osteoconductive plasma-sprayed hydroxyapatite coatings. The present work explores the use of the innovative High Velocity Suspension Flame Spraying (HVSFS) process to coat Ti substrates with thin homogeneous hydroxyapatite coatings. The HVSFS hydroxyapatite coatings studied were dense, 27–37 μm thick, with some transverse microcracks. Lamellae were sintered together and nearly unidentifiable, unlike conventional plasma-sprayed hydroxyapatite. Crystallinities of 10%–70% were obtained, depending on the deposition parameters and the use of a TiO{sub 2} bond coat. The average hardness of layers with low (< 24%) and high (70%) crystallinity was ≈ 3.5 GPa and ≈ 4.5 GPa respectively. The distributions of hardness values, all characterised by Weibull modulus in the 5–7 range, were narrower than that of conventional plasma-sprayed hydroxyapatite, with a Weibull modulus of ≈ 3.3. During soaking in simulated body fluid, glassy coatings were progressively resorbed and replaced by a new, precipitated hydroxyapatite layer, whereas coatings with 70% crystallinity were stable up to 14 days of immersion. The interpretation of the precipitation behaviour was also assisted by surface charge assessments, performed through Z-potential measurements. During in vitro tests, HA coatings showed no cytotoxicity towards the SAOS-2 osteoblast cell line, and surface cell proliferation was comparable with proliferation on reference polystyrene culture plates. - Highlights: • Thin, dense HA layers were originated by HVSFS deposition of molten agglomerates of ≈ 1 μm. • Tensile adhesion strength of HVSFS HA onto Ti well above the threshold of ISO 13779-2 • Crystallinity (10–70%) is determined by system temperature during deposition. • Crystallinity controls the reactivity during immersion in simulated body fluid. • SAOS-2 osteoblast-like cells adhered well and

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

International Nuclear Information System (INIS)

Parente, P.; Savoini, B.; Ferrari, B.; Monge, M.A.; Pareja, R.; Sanchez-Herencia, A.J.

2013-01-01

The capability of the colloidal method to produce yttria (Y 2 O 3 ) dispersed hydroxyapatite (HA) has been investigated as an alternative method to the conventional method of mechanical mixing and sintering for developing HA-based materials that could exhibit controllable and enhanced functional properties. A water based colloidal route to produce HA materials with highly dispersed Y 2 O 3 has been applied, and the effect of 10 wt.% Y 2 O 3 addition to HA investigated by thermal analysis, X-ray diffraction and Fourier transform infrared spectroscopy. These measurements evidence a remarkable effect of this Y 2 O 3 addition on decomposition mechanisms of synthetic HA. Results show that incorporation of Y 2 O 3 as dispersed second phase is beneficial because it hinders the decomposition mechanisms of HA into calcium phosphates. This retardation will allow the control of the sintering conditions for developing HA implants with improved properties. Besides, substitution of Ca 2+ with Y 3+ ions appears to promote the formation of OH − vacancies, which could improve the conductive properties of HA favorable to osseointegration. - Highlights: ► We reveal the influence of Y 2 O 3 on thermal stability of hydroxyapatite. ► Incorporation of Y 2 O 3 delays decomposition of hydroxyapatite to calcium phosphates. ► Addition of Y 2 O 3 enables sintering conditions more favorable to the densification.

Oriented hydroxyapatite single crystals produced by the electrodeposition method

Energy Technology Data Exchange (ETDEWEB)

Santos, E.A. dos, E-mail: euler@ufs.br [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Moldovan, M.S. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Jacomine, L. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); Mateescu, M. [IS2M - Equipe Interaction Surface-Matiere Vivant, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse (France); Werckmann, J. [IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Anselme, K. [IS2M - Equipe Interaction Surface-Matiere Vivant, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse (France); Mille, P.; Pelletier, H. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France)

2010-05-25

We propose here the use of cathodic electrodeposition as tool to fabricate implant coatings consisting in nano/micro single crystals of hydroxyapatite (HA), preferentially orientated along the c-axis. Coating characterization is the base of this work, where we discuss the mechanisms related to the deposition of oriented hydroxyapatite thin films. It is shown that when deposited on titanium alloys, the HA coating is constituted by two distinct regions with different morphologies: at a distance of few microns from the substrate, large HA single crystals are oriented along the c-axis and appear to grow up from a base material, consisting in an amorphous HA. This organized system has a great importance for cell investigation once the variables involved in the cell/surface interaction are reduced. The use of such systems could give a new insight on the effect of particular HA orientation on the osteoblast cells.

FIBROUS SILICA-HYDROXYAPATITE COMPOSITE BY ELECTROSPINNING

OpenAIRE

Jesús Alberto Garibay-Alvarado; León Francisco Espinosa-Cristóbal; Simón Yobanny Reyes-López

2017-01-01

New nanocomposite membrane was fabricated by electrospinning. The nanocomposite combines a glass and hydroxyapatite (HA). This research proposed the incorporation of glass to counteract the brittleness of HA in a composite formed by coaxial fibers which will be used for bone replacement. Calcium phosphate ceramics are used widely for dental and orthopedic reasons, because they can join tightly through chemical bonds and promote bone regeneration. Precursors HA and SiO2 were synthetized throug...

Effect of Hydroxyapatite on Bone Integration in a Rabbit Tibial Defect Model

Science.gov (United States)

Sohn, Sung-Keun; Kim, Kyung-Taek; Kim, Chul-Hong; Ahn, Hee-Bae; Rho, Mee-Sook; Jeong, Min-Ho; Sun, Sang-Kyu

2010-01-01

Background The aim of the present study was to prepare hydroxyapatite (HA) and then characterize its effect on bone integration in a rabbit tibial defect model. The bone formation with different designs of HA was compared and the bony integration of several graft materials was investigated qualitatively by radiologic and histologic study. Methods Ten rabbits were included in this study; two holes were drilled bilaterally across the near cortex and the four holes in each rabbit were divided into four treatment groups (HAP, hydroxyapatite powder; HAC, hydroxyapatite cylinder; HA/TCP, hydroxyapatite/tri-calcium phosphate cylinder, and titanium cylinder). The volume of bone ingrowth and the change of bone mineral density were statistically calculated by computed tomography five times for each treatment group at 0, 2, 4, 6, and 8 weeks after grafting. Histologic analysis was performed at 8 weeks after grafting. Results The HAP group showed the most pronounced effect on the bone ingrowth surface area, which seen at 4, 6, and 8 weeks after graft (p 0.05). On histological examination, the HAP group revealed well-recovered cortical bone, but the bone was irregularly thickened and haphazardly admixed with powder. The HAC group showed similar histological features to those of the HA/TCP group; the cortical surface of the newly developed bone was smooth and the bone matrix on the surface of the cylinder was regularly arranged. Conclusions We concluded that both the hydroxyapatite powder and cylinder models investigated in our study may be suitable as a bone substitute in the rabbit tibial defect model, but their characteristic properties are quite different. In contrast to hydroxyapatite powder, which showed better results for the bone ingrowth surface, the hydroxyapatite cylinder showed better results for the sustained morphology. PMID:20514266

Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

Energy Technology Data Exchange (ETDEWEB)

Parcharoen, Yardnapar [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Kajitvichyanukul, Puangrat [Center of Excellence on Environmental Research and Innovation, Faculty of Engineering, Naresuan University, Phitsanulok (Thailand); Sirivisoot, Sirinrath [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Termsuksawad, Preecha, E-mail: preecha.ter@kmutt.ac.th [Division of Materials Technology, School of Energy, Environment and Materials, King Mongkut' s University of Technology Thonburi, 126 Pracha Uthit Rd., Bang Mod, ThungKhru, Bangkok 10140 (Thailand)

2014-08-30

Highlights: • We found that different anodization time of titanium significantly effects on nanotube length which further impacts adhesion strength of hydroxyapatite coating layers. • Adhesion strength of Hydroxyapatite (HA) coated on titanium dioxide nanotubes is better than that of HA coated on titanium plate. • Hydroxyapatite coated on titanium dioxide nanotubes showed higher cell density and better spreading of MC3T3-E1 cells (bone-forming cells) than that coated on titanium plate surface. - Abstract: Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO{sub 2}) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO{sub 2} nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH{sub 4}F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO{sub 2} nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO{sub 2} nanotubes were found when high viscous electrolyte, NH{sub 4}F in glycerol, was used. Negative voltage (−4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO{sub 2} nanotubes was significantly increased by times. The TiO{sub 2} nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO{sub 2} nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that

Cadmium fixation by synthetic hydroxyapatite in aqueous solution-Thermal behaviour

International Nuclear Information System (INIS)

Marchat, David; Bernache-Assollant, Didier; Champion, Eric

2007-01-01

This study deals with the mechanism of the cadmium uptake by synthetic hydroxyapatite (HA: Ca 10 (PO 4 ) 6 (OH) 2 ) in aqueous solution. The rate of cadmium fixation by hydroxyapatite was investigated at 10 and 50 deg. C using batch experiments. Inductively coupled plasma atomic emission spectrometry, X-ray diffraction, FT-IR spectroscopy and electron microscopy were used to characterize the starting HA and the samples. The thermal behaviour of the powders was determined with the help of three thermoanalytical techniques (TGA, DTA, and MS) and temperature programmed X-ray diffraction. Cadmium immobilization kinetics can be divided into two steps: substitution of Ca 2+ ions by Cd 2+ in the HA lattice at the particle's surface, followed by their incorporation into the hydroxyapatite bulk. This results in the formation of an apatite solid solution, which is very important because in this way decontamination and storage can be performed with the same material

Modified composite microspheres of hydroxyapatite and poly(lactide-co-glycolide) as an injectable scaffold

Energy Technology Data Exchange (ETDEWEB)

Hu, Xixue [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190 (China); Shen, Hong, E-mail: shenhong516@iccas.ac.cn [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Fei [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liang, Xinjie [CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190 (China); Wang, Shenguo, E-mail: wangsg@iccas.ac.cn [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Decheng, E-mail: dcwu@iccas.ac.cn [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

2014-02-15

The compound of hydroxyapatite-poly(lactide-co-glycolide) (HA-PLGA) was prepared by ionic bond between HA and PLGA. HA-PLGA was more stable than the simple physical blend of hydroxyapatite and poly(lactide-co-glycolide) (HA/PLGA). The surface of HA-PLGA microsphere fabricated by an emulsion–solvent evaporation method was rougher than that of HA/PLGA microspheres. Moreover, surface HA content of HA-PLGA microspheres was more than that of HA/PLGA microspheres. In vitro mouse OCT-1 osteoblast-like cell culture results showed that the HA-PLGA microspheres clearly promoted osteoblast attachment, proliferation and alkaline phosphatase activity. It was considered that surface rich HA component and rough surface of HA-PLGA microsphere enhanced cell growth and differentiation. The good cell affinity of the HA-PLGA microspheres indicated that they could be used as an injectable scaffold for bone tissue engineering.

Modified composite microspheres of hydroxyapatite and poly(lactide-co-glycolide) as an injectable scaffold

International Nuclear Information System (INIS)

Hu, Xixue; Shen, Hong; Yang, Fei; Liang, Xinjie; Wang, Shenguo; Wu, Decheng

2014-01-01

The compound of hydroxyapatite-poly(lactide-co-glycolide) (HA-PLGA) was prepared by ionic bond between HA and PLGA. HA-PLGA was more stable than the simple physical blend of hydroxyapatite and poly(lactide-co-glycolide) (HA/PLGA). The surface of HA-PLGA microsphere fabricated by an emulsion–solvent evaporation method was rougher than that of HA/PLGA microspheres. Moreover, surface HA content of HA-PLGA microspheres was more than that of HA/PLGA microspheres. In vitro mouse OCT-1 osteoblast-like cell culture results showed that the HA-PLGA microspheres clearly promoted osteoblast attachment, proliferation and alkaline phosphatase activity. It was considered that surface rich HA component and rough surface of HA-PLGA microsphere enhanced cell growth and differentiation. The good cell affinity of the HA-PLGA microspheres indicated that they could be used as an injectable scaffold for bone tissue engineering.

Mechanical strength of [HA/Bioplastic/Sericin] composite part printed by bioprinter

Energy Technology Data Exchange (ETDEWEB)

Tontowi, Alva Edy, E-mail: alvaedytontowi@ugm.ac.id; Setiawan, Agris [Department of Mechanical and Industrial Engineering Faculty of Engineering Universitas Gadjah Mada (Indonesia)

2016-06-17

The aim of this research was to determine the effect of hydroxyapatite (HA) content in printed biocomposite to its mechanical strength. The biocomposite paste was prepared by composing HA, bioplastic and sericin with various ratios of [HA/Bioplastic]: 40/60, 50/50, 60,40 and 70/30. Sericin of 0.3% weight was added to the biocomposite. Mechanical test was conducted to observe tensile (ASTM D 638 type 4) and flexural strength (ASTM D 790). Both type of specimens were fabricated using 3D Printer. Printing process parameter (infill speed, print speed and layer height) were set up as 60 mm/s, 10 mm/s, 0.35 mm, respectively. Results showed that biocomposite with [HA/Biplastic]. weight ratio of 60/40(w/w) has an optimum tensile (3.89 ± 1.26 MPa) and flexural strength (2.51 ± 0.45 MPa). Scanning electron microscope observation indicated that microstructure of specimen was influenced by the percentage of the hydroxyapatite. There was no agglomeration of HA particle within the composite.

Mechanical strength of [HA/Bioplastic/Sericin] composite part printed by bioprinter

International Nuclear Information System (INIS)

Tontowi, Alva Edy; Setiawan, Agris

2016-01-01

The aim of this research was to determine the effect of hydroxyapatite (HA) content in printed biocomposite to its mechanical strength. The biocomposite paste was prepared by composing HA, bioplastic and sericin with various ratios of [HA/Bioplastic]: 40/60, 50/50, 60,40 and 70/30. Sericin of 0.3% weight was added to the biocomposite. Mechanical test was conducted to observe tensile (ASTM D 638 type 4) and flexural strength (ASTM D 790). Both type of specimens were fabricated using 3D Printer. Printing process parameter (infill speed, print speed and layer height) were set up as 60 mm/s, 10 mm/s, 0.35 mm, respectively. Results showed that biocomposite with [HA/Biplastic]. weight ratio of 60/40(w/w) has an optimum tensile (3.89 ± 1.26 MPa) and flexural strength (2.51 ± 0.45 MPa). Scanning electron microscope observation indicated that microstructure of specimen was influenced by the percentage of the hydroxyapatite. There was no agglomeration of HA particle within the composite.

Post-translational modification of osteopontin: Effects on in vitro hydroxyapatite formation and growth

International Nuclear Information System (INIS)

Boskey, Adele L.; Christensen, Brian; Taleb, Hayat; Sørensen, Esben S.

2012-01-01

Highlights: ► Thrombin-cleaved fragments of milk-osteopontin effect hydroxyapatite formation differently. ► N- and C-terminal fragments promoted hydroxyapatite formation and growth. ► A central fragment inhibited hydroxyapatite formation and growth. ► Binding to collagen or hydroxyapatite seed crystals modified these effects. -- Abstract: The manuscript tests the hypothesis that posttranslational modification of the SIBLING family of proteins in general and osteopontin in particular modify the abilities of these proteins to regulate in vitro hydroxyapatite (HA) formation. Osteopontin has diverse effects on hydroxyapatite (HA) mineral crystallite formation and growth depending on the extent of phosphorylation. We hypothesized that different regions of full-length OPN would also have distinct effects on the mineralization process. Thrombin fragmentation of milk OPN (mOPN) was used to test this hypothesis. Three fragments were tested in a de novo HA formation assay; an N-terminal fragment (aa 1–147), a central fragment (aa 148–204) denoted SKK-fragment and a C-terminal fragment (aa 205–262). Compared to intact mOPN the C- and N-terminal fragments behaved comparably, promoting HA formation and growth, but the central SKK-fragment acted as a mineralization inhibitor. In a seeded growth experiment all fragments inhibited mineral proliferation, but the SKK-fragment was the most effective inhibitor. These effects, seen in HA-formation and seeded growth assays in a gelatin gel system and in a pH-stat experiment were lost when the protein or fragments were dephosphorylated. Effects of the fully phosphorylated protein and fragments were also altered in the presence of fibrillar collagen. The diverse effects can be explained in terms of the intrinsically disordered nature of OPN and its fragments which enable them to interact with their multiple partners.

Hydroxyapatite formation on biomedical Ti–Ta–Zr alloys by magnetron sputtering and electrochemical deposition

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun-Ju [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Prosthodontics and Restorative Science, College of Dentistry, The Ohio State University, Columbus, OH (United States)

2014-12-01

The purpose of this study was to investigate hydroxyapatite formation on Ti-25Ta-xZr titanium alloys resulting from radio-frequency magnetron sputtering and electrochemical deposition. Electrochemical deposition of hydroxyapatite (HA) was first carried out using a cyclic voltammetry (CV) method at 80 °C in 5 mM Ca (NO{sub 3}){sub 2} + 3 mM NH{sub 4}H{sub 2}PO{sub 4}. Then a physical vapor deposition (PVD) coating was obtained by a radio-frequency (RF) magnetron sputtering technique. The microstructures, phase transformations, and morphologies of the hydroxyapatite films deposited on the titanium alloys were analyzed by optical microscopy (OM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FE-SEM). The morphologies of electrochemically deposited HA showed plate-like shapes on the titanium alloys, and the morphologies of the RF-sputtered HA coating had the appearance droplet particles on the plate-like precipitates that had formed by electrochemical deposition. For the RF-sputtered HA coatings, the Ca/P ratio was increased, compared to that for the electrochemically deposited HA surface. Moreover, the RF-sputtered HA coating, consisting of agglomerated droplet particles on the electrochemically deposited HA surface, had better wettability compared to the bulk titanium alloy surface. - Highlights: • Hydroxyapatite (HA) was deposited on Ti–Ta–Zr alloys by radio-frequency (RF) magnetron sputtering and a cyclic voltammetry. • The morphologies of the RF-sputtered HA coating on electrochemical deposits presented plate-like shapes with a droplet particle. • The Ca/P ratio for RF-sputtered HA coatings was greater than that for electrochemical deposited HA coatings. • The RF-sputtered and electrochemical HA coatings had superior wettability compared to the electrochemically deposited coatings.

Hydroxyapatite formation on biomedical Ti–Ta–Zr alloys by magnetron sputtering and electrochemical deposition

International Nuclear Information System (INIS)

Kim, Hyun-Ju; Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

2014-01-01

The purpose of this study was to investigate hydroxyapatite formation on Ti-25Ta-xZr titanium alloys resulting from radio-frequency magnetron sputtering and electrochemical deposition. Electrochemical deposition of hydroxyapatite (HA) was first carried out using a cyclic voltammetry (CV) method at 80 °C in 5 mM Ca (NO 3 ) 2 + 3 mM NH 4 H 2 PO 4 . Then a physical vapor deposition (PVD) coating was obtained by a radio-frequency (RF) magnetron sputtering technique. The microstructures, phase transformations, and morphologies of the hydroxyapatite films deposited on the titanium alloys were analyzed by optical microscopy (OM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FE-SEM). The morphologies of electrochemically deposited HA showed plate-like shapes on the titanium alloys, and the morphologies of the RF-sputtered HA coating had the appearance droplet particles on the plate-like precipitates that had formed by electrochemical deposition. For the RF-sputtered HA coatings, the Ca/P ratio was increased, compared to that for the electrochemically deposited HA surface. Moreover, the RF-sputtered HA coating, consisting of agglomerated droplet particles on the electrochemically deposited HA surface, had better wettability compared to the bulk titanium alloy surface. - Highlights: • Hydroxyapatite (HA) was deposited on Ti–Ta–Zr alloys by radio-frequency (RF) magnetron sputtering and a cyclic voltammetry. • The morphologies of the RF-sputtered HA coating on electrochemical deposits presented plate-like shapes with a droplet particle. • The Ca/P ratio for RF-sputtered HA coatings was greater than that for electrochemical deposited HA coatings. • The RF-sputtered and electrochemical HA coatings had superior wettability compared to the electrochemically deposited coatings

Biological activity of lactoferrin-functionalized biomimetic hydroxyapatite nanocrystals

Directory of Open Access Journals (Sweden)

Nocerino N

2014-03-01

Full Text Available Nunzia Nocerino,1 Andrea Fulgione,1 Marco Iannaccone,1 Laura Tomasetta,1 Flora Ianniello,1 Francesca Martora,1 Marco Lelli,2 Norberto Roveri,2 Federico Capuano,3 Rosanna Capparelli1 1Department of Agriculture Special Biotechnology Center Federico II, CeBIOTEC Biotechnology, University of Naples Federico II, Naples, 2Department of Chemistry, G Ciamician, Alma Mater Studiorum, University of Bologna, Bologna, 3Department of Food Inspection IZS ME, Naples, Italy Abstract: The emergence of bacterial strains resistant to antibiotics is a general public health problem. Progress in developing new molecules with antimicrobial properties has been made. In this study, we evaluated the biological activity of a hybrid nanocomposite composed of synthetic biomimetic hydroxyapatite surface-functionalized by lactoferrin (LF-HA. We evaluated the antimicrobial, anti-inflammatory, and antioxidant properties of LF-HA and found that the composite was active against both Gram-positive and Gram-negative bacteria, and that it modulated proinflammatory and anti-inflammatory responses and enhanced antioxidant properties as compared with LF alone. These results indicate the possibility of using LF-HA as an antimicrobial system and biomimetic hydroxyapatite as a candidate for innovative biomedical applications. Keywords: lactoferrin, hydroxyapatite nanocrystals, biomimetism, biological activity, drug delivery

Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

International Nuclear Information System (INIS)

Chao, Shao Ching; Wang, Ming-Jia; Pai, Nai-Su; Yen, Shiow-Kang

2015-01-01

Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO 3 ) 2 , NH 4 H 2 PO 4 and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space

Histomorphometric analysis of rat alveolar wound healing with hydroxyapatite alone or associated to BMPs

Directory of Open Access Journals (Sweden)

Brandão Alexandre C.

2002-01-01

Full Text Available Several materials and techniques have been proposed to improve alveolar wound healing and decrease loss of bone height and thickness that normally follow dental extraction. The objective of this research was the histologic analysis of bone morphogenetic proteins implanted into dental alveoli of rats after extraction. A total of 45 adult male Wistar rats were divided into three groups of 15 animals each: control (no treatment, implanted with pure hydroxyapatite (HA, 3 mg and implanted with hydroxyapatite plus bone morphogenetic proteins (HA/BMPs, 3 mg. Five animals from each group were sacrificed at 7, 21 and 42 days after extraction for the histometric analyses of the osteoconductive potential of hydroxyapatite associated or not with BMPs. After dissection, fixation, decalcification and serial microtomy of 6-mm thick sections, the samples were stained with hematoxylin-eosin for histologic and histometric analyses. Both HA and HA/BMPs caused a delay in wound healing compared to control animals, evaluated by the percentage of bone tissue in the alveoli. The treatment with HA/BMPs had the greatest delay at 21 days, even though it produced values similar to the control group at 42 days. The materials did not improve alveolar repair in the normal period of wound healing and the association of HA/BMPs did not have osteoconductive properties with granulated hydroxyapatite as the vehicle.

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.

Scaffolds for bone regeneration made of hydroxyapatite microspheres in a collagen matrix

Energy Technology Data Exchange (ETDEWEB)

Cholas, Rahmatullah, E-mail: rahmat.cholas@gmail.com; Kunjalukkal Padmanabhan, Sanosh, E-mail: sanosh2001@gmail.com; Gervaso, Francesca; Udayan, Gayatri; Monaco, Graziana; Sannino, Alessandro; Licciulli, Antonio

2016-06-01

Biomimetic scaffolds with a structural and chemical composition similar to native bone tissue may be promising for bone tissue regeneration. In the present work hydroxyapatite mesoporous microspheres (mHA) were incorporated into collagen scaffolds containing an ordered interconnected macroporosity. The mHA were obtained by spray drying of a nano hydroxyapatite slurry prepared by the precipitation technique. X-ray diffraction (XRD) analysis revealed that the microspheres were composed only of hydroxyapatite (HA) phase, and energy-dispersive x-ray spectroscopy (EDS) analysis revealed the Ca/P ratio to be 1.69 which is near the value for pure HA. The obtained microspheres had an average diameter of 6 μm, a specific surface area of 40 m{sup 2}/g as measured by Brunauer-Emmett-Teller (BET) analysis, and Barrett-Joyner-Halenda (BJH) analysis showed a mesoporous structure with an average pore diameter of 16 nm. Collagen/HA-microsphere (Col/mHA) composite scaffolds were prepared by freeze-drying followed by dehydrothermal crosslinking. SEM observations of Col/mHA scaffolds revealed HA microspheres embedded within a porous collagen matrix with a pore size ranging from a few microns up to 200 μm, which was also confirmed by histological staining of sections of paraffin embedded scaffolds. The compressive modulus of the composite scaffold at low and high strain values was 1.7 and 2.8 times, respectively, that of pure collagen scaffolds. Cell proliferation measured by the MTT assay showed more than a 3-fold increase in cell number within the scaffolds after 15 days of culture for both pure collagen scaffolds and Col/mHA composite scaffolds. Attractive properties of this composite scaffold include the potential to load the microspheres for drug delivery and the controllability of the pore structure at various length scales. - Highlights: • Mesoporous hydroxyapatite microsphere(mHA) synthesized by spray drying method • Porous collagen/mHA composite scaffold made by freeze

Biomimetic properties of an injectable chitosan/nano-hydroxyapatite/collagen composite

Energy Technology Data Exchange (ETDEWEB)

Huang Zhi [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Feng Qingling, E-mail: biomater@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Yu Bo; Li Songjian [Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou 510282 (China)

2011-04-08

To meet the challenges of designing an injectable scaffold and regenerating bone with complex three-dimensional (3D) structures, a biomimetic and injectable hydrogel scaffold based on nano-hydroxyapatite (HA), collagen (Col) and chitosan (Chi) is synthesized. The chitosan/nano-hydroxyapatite/collagen (Chi/HA/Col) solution rapidly forms a stable gel at body temperature. It shows some features of natural bone both in main composition and microstructure. The Chi/HA/Col system can be expected as a candidate for workable systemic minimally invasive scaffolds with surface properties similar to physiological bone based on scanning electron microscopic (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) results.

Biomimetic properties of an injectable chitosan/nano-hydroxyapatite/collagen composite

International Nuclear Information System (INIS)

Huang Zhi; Feng Qingling; Yu Bo; Li Songjian

2011-01-01

To meet the challenges of designing an injectable scaffold and regenerating bone with complex three-dimensional (3D) structures, a biomimetic and injectable hydrogel scaffold based on nano-hydroxyapatite (HA), collagen (Col) and chitosan (Chi) is synthesized. The chitosan/nano-hydroxyapatite/collagen (Chi/HA/Col) solution rapidly forms a stable gel at body temperature. It shows some features of natural bone both in main composition and microstructure. The Chi/HA/Col system can be expected as a candidate for workable systemic minimally invasive scaffolds with surface properties similar to physiological bone based on scanning electron microscopic (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) results.

Silver doped hydroxyapatite coatings by sacrificial anode deposition under magnetic field.

Science.gov (United States)

Swain, S; Rautray, T R

2017-09-13

Uniform distribution of silver (Ag) in the hydroxyapatite (HA) coated Ti surface has been a concern for which an attempt has been made to dope Ag in HA coating with and without magnetic field. Cathodic deposition technique was employed to coat Ag incorporated hydroxyapatite coating using a sacrificial silver anode method by using NdFeB bar magnets producing 12 Tesla magnetic field. While uniform deposition of Ag was observed in the coatings under magnetic field, dense coating was evident in the coating without magnetic field conditions. Uniformly distributed Ag incorporated HA in the present study has potential to fight microorganism while providing osseoconduction properties of the composite coating.

Preparation and characterization of collagen-hydroxyapatite/pectin composite.

Science.gov (United States)

Wenpo, Feng; Gaofeng, Liang; Shuying, Feng; Yuanming, Qi; Keyong, Tang

2015-03-01

Pectin, a kind of plant polysaccharide, was introduced into collagen-hydroxyapatite composite system, and prepared collagen-hydroxyapatite/pectin (Col-HA/pectin) composite in situ. The structure of the composite was investigated by XRD, SEM, and FT-IR. The mechanical properties, water absorption, enzyme degradation, and cytotoxicity of the composite were investigated as well. The results show that the inorganic substance in the composite materials is hydroxyapatite in relatively low crystallinity. A new interface appeared by the interaction among hydroxyapatite and collagen-pectin, and formed smooth fine particles. The mechanical properties, water absorption, enzyme degradation, and cytotoxicity indicate a potential use in bone replacement for the new composite. Copyright © 2014 Elsevier B.V. All rights reserved.

Adsorption pertechnetate ions on the substituted Sn-hydroxyapatite

International Nuclear Information System (INIS)

Hamarova, A.; Rosskopfova, O.; Pivarciova, L.

2015-01-01

Hydroxyapatite is suitable adsorbent for heavy metals and radionuclides due to its large surface area, high stability under redox conditions. SnCl 2 for its reducing properties is used in biomedical applications and industrial technologies, for its reducing properties. The adsorption of TcO 4 - to the HA samples, prepared by wet precipitation method, was studied by the d radio-indication method. Radionuclide 99m Tc was used as radioisotope indicator. The effect of contact time on the adsorption of 99m TcO 4 - ions on the Sn-HA was studied. Sn 2+ ions reduced Tc (VII) to Tc (IV) forming TcO 2 , TcO(OH) 2 or more precisely TcO 2 ·2H 2 O, which can be adsorbed on the surface of the HA, or to form complexes on the surface of the hydroxyapatite. (authors)

N-Lauroyl sarcosine sodium salt mediated formation of hydroxyapatite microspheres via a hydrothermal route

International Nuclear Information System (INIS)

Xiao Xiufeng; Zheng Xuan; Liu Rongfang; Lu Yihua; Wu Shanshan

2012-01-01

Dandelion-like hydroxyapatite (HA) microspheres were successfully prepared using Ca(NO 3 ) 2 ·4H 2 O and (NH 4 ) 3 PO 4 ·3H 2 O as raw materials and N-Lauroyl sarcosine sodium salt (Sar-Na) as template via a hydrothermal route. The chemical composition, structure, morphology and thermal properties of the samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), Scanning electron microscope (SEM) and Thermal gravimetric analysis (TG), respectively. The results demonstrate that, Sar-Na has great impact on the morphology of HA. With increasing the amount of Sar-Na, the morphology of HA varies from nanograins to nanorods, finally grows into dandelion-like microstructure. The obtained dandelion-like HA microspheres about 6 μm in diameter are composed of radially oriented nanorods. Furthermore, the possible formation mechanism of morphology change is also discussed. - Highlights: ► N-Lauroyl sarcosine sodium salt is firstly used to control the morphology of hydroxyapatite. ► The mechanism of Sar-Na on the morphology of hydroxyapatite are discussed in this paper. ► The dandelion-like microsphere hydroxyapatite are obtained at suitable conditions.

Iron(III) and manganese(II) substituted hydroxyapatite nanoparticles: Characterization and cytotoxicity analysis

International Nuclear Information System (INIS)

Li Yan; Nam, C T; Ooi, C P

2009-01-01

Calcium hydroxyapatite (HA) is the main inorganic component of natural bones and can bond to bone directly in vivo. Thus HA is widely used as coating material on bone implants due to its good osteoconductivity and osteoinductivity. Metal ions doped HA have been used as catalyst or absorbents since the ion exchange method has introduced new properties in HA which are inherent to the metal ions. For example, Mn 2+ ions have the potential to increase cell adhesion while Fe 3+ ions have magnetic properties. Here, Fe(III) substituted hydroxyapatite (Fe-HA) and Mn(II) substituted hydroxyapatite (Mn-HA) were produced by wet chemical method coupled with ion exchange mechanism. Compared with pure HA, the colour of both Fe-HA and Mn-HA nanoparticles changed from white to brown and pink respectively. The intensity of the colours increased with increasing substitution concentrations. XRD patterns showed that all samples were single phased HA while the FTIR spectra revealed all samples possessed the characteristic phosphate and hydroxyl adsorption bands of HA. However, undesired adsorption bands of carbonate substitution (B-type carbonated HA) and H 2 O were also detected, which was reasonable since the wet chemical method was used in the synthesis of these nanoparticles. FESEM images showed all samples were elongated spheroids with small size distribution and of around 70 nm, regardless of metal ion substitution concentrations. EDX spectra showed the presence of Fe and Mn and ICP-AES results revealed all metal ion substituted HA were non-stoichiometric (Ca/P atomic ratio deviates from 1.67). Fe-HA nanoparticles were paramagnetic and the magnetic susceptibility increased with the increase of Fe content. Based on the extraction assay for cytotoxicity test, both Fe-HA and Mn-HA displayed non-cytotoxicity to osteoblast.

Novel synthesis and characterization of an AB-type carbonate-substituted hydroxyapatite.

Science.gov (United States)

Gibson, Iain R; Bonfield, William

2002-03-15

A novel synthesis route has been developed to produce a high-purity mixed AB-type carbonate-substituted hydroxyapatite (CHA) with a carbonate content that is comparable to the type and level observed in bone mineral. This method involves the aqueous precipitation in the presence of carbonate ions in solution of a calcium phosphate apatite with a Ca/P molar ratio greater than the stoichiometric value of 1.67 for hydroxyapatite (HA). The resulting calcium-rich carbonate-apatite is sintered/heat-treated in a carbon dioxide atmosphere to produce a single-phase, crystalline carbonate-substituted hydroxyapatite. In contrast to previous methods for producing B- or AB-type carbonate-substituted hydroxyapatites, no sodium or ammonium ions, which would be present in the reaction mixture from the sodium or ammonium carbonates commonly used as a source of carbonate ions, were present in the final product. The chemical and phase compositions of the carbonate-substituted hydroxyapatite was characterized by X-ray fluorescence and X-ray diffraction, respectively, and the level and nature of the carbonate substitution were studied using C-H-N analysis and Fourier transform infrared spectroscopy, respectively. The carbonate substitution improves the densification of hydroxyapatite and reduces the sintering temperature required to achieve near-full density by approximately 200 degrees C compared to stoichiometric HA. Initial studies have shown that these carbonate-substituted hydroxyapatites have improved mechanical and biologic properties compared to stoichiometric hydroxyapatite. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 59: 697-708, 2002

Direct growth of carbon nanotubes on hydroxyapatite using MPECVD

International Nuclear Information System (INIS)

Duraia, El-Shazly M.; Hannora, A.; Mansurov, Z.; Beall, Gary W.

2012-01-01

Graphical abstract: Carbon nanotubes have been grown directly on hydroxyapatite by using microwave plasma-enhanced chemical vapor deposition (MPECVD). Highlights: ► CNTs have been successfully grown directly on hydroxyapatite using MPECVD. ► Diameter distribution of the CNTs lies in the range from 30 to 70 nm. ► The HA surface is partially transformed to β-TCP during the deposition. ► Grown CNTs have good quality and I G /I D ratio lies between 1.243 and 1.774. - Abstract: For the first time carbon nanotubes (CNTs) have been successfully grown directly on hydroxyapatite (HA) by using microwave plasma enhanced chemical vapor deposition (MPECVD). Such integration has potential to capitalize on the merits of both HA and CNTs. This type of coating could be useful to improve the interface between bone and the implant. Scanning electron microscope SEM investigations show that; the surface of the CNTs is relatively clean and free of amorphous carbon. The CNTs diameters lie in the range 30–70 nm. In addition HA encapsulation by carbon was observed at a growth temperature 750 °C. Raman spectroscopy indicates that the CNTs are of high quality and the I G /I D ratio lies between 1.243 and 1.774. The changes in the X-ray diffraction (XRD) patterns give an indication that during the plasma deposition the HA-substrate surface is subjected to a temperature sufficient for partial conversion to the β-tricalcium phosphate via dehydroxylation.

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)

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.

Mechanical properties and in vivo study of modified-hydroxyapatite/polyetheretherketone biocomposites

Energy Technology Data Exchange (ETDEWEB)

Ma, Rui [College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China, (China); Li, Qiankuan [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518060 (China); Wang, Lin, E-mail: wanglinhitsz@163.com [Shenzhen Institute of Geriatrics, Shenzhen 518020 (China); Zhang, Xianghua [College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China, (China); Laboratory of Glasses and Ceramics, Institute of Chemical Science, University of Rennes 1, Rennes 35042 (France); Fang, Lin; Luo, Zhongkuan; Xue, Bai [College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China, (China); Ma, Lei, E-mail: leima@szu.edu.cn [College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China, (China)

2017-04-01

Polyether ether ketone (PEEK) has received much attention for its excellent mechanical properties and biocompatibility. Here, the silane coupling agent KH560 [γ-(2,3-epoxypropoxy)propyltrimethoxysilane] is used for graft modification of bioactive HA (hydroxyapatite) particles and for preparing HA/PEEK composites via a hot-press molding method. The prepared HA/PEEK composites were tested for their mechanical properties with SEM (scanning electron microscopy), infrared spectroscopy, and thermo-analysis. The results show that silane coupling KH-560 modifies HA successfully and that the tensile strengths of HA/PEEK and m-HA/PEEK composites indicate an increasing and then a decreasing tendency with increasing HA contents. The non-modified HA/PEEK composites display the same trend as the modified specimens with lower tensile strength and consist of sharp points. When the HA content is 5 wt.%, the tensile strength of m-HA/PEEK composite reaches its maximum, which is 23% higher than that of pure PEEK specimens. The in vivo experiments of m-HA/PEEK used a biomechanical push-out test, SEM, optical microscopy, and an Image-Pro Express C image analysis system. The growth of the bone tissues around the m-HA/PEEK composites with an HA content of 5 wt.% is better than that of specimens with different HA contents. This finding shows the nano-scale effect of the bioactive filler HA in PEEK substrates, which obviously contributes to the growth of the surrounding bone issues in vivo. This study could provide theoretical support for the further promotion and application of high-performance engineering plastics such as PEEK in biomedical fields. - Highlight: • The modification of hydroxyapatite with KH-560 can increase the efficient dispersion of hydroxyapatite in PEEK substrates. • When the HA content is 5 wt. %, the tensile strength of modified-HA/PEEK composite reaches its maximum. • The nano-scale effect of HA fillers in PEEK substrates contributes to the growth of the

Mechanical properties and in vivo study of modified-hydroxyapatite/polyetheretherketone biocomposites

International Nuclear Information System (INIS)

Ma, Rui; Li, Qiankuan; Wang, Lin; Zhang, Xianghua; Fang, Lin; Luo, Zhongkuan; Xue, Bai; Ma, Lei

2017-01-01

Polyether ether ketone (PEEK) has received much attention for its excellent mechanical properties and biocompatibility. Here, the silane coupling agent KH560 [γ-(2,3-epoxypropoxy)propyltrimethoxysilane] is used for graft modification of bioactive HA (hydroxyapatite) particles and for preparing HA/PEEK composites via a hot-press molding method. The prepared HA/PEEK composites were tested for their mechanical properties with SEM (scanning electron microscopy), infrared spectroscopy, and thermo-analysis. The results show that silane coupling KH-560 modifies HA successfully and that the tensile strengths of HA/PEEK and m-HA/PEEK composites indicate an increasing and then a decreasing tendency with increasing HA contents. The non-modified HA/PEEK composites display the same trend as the modified specimens with lower tensile strength and consist of sharp points. When the HA content is 5 wt.%, the tensile strength of m-HA/PEEK composite reaches its maximum, which is 23% higher than that of pure PEEK specimens. The in vivo experiments of m-HA/PEEK used a biomechanical push-out test, SEM, optical microscopy, and an Image-Pro Express C image analysis system. The growth of the bone tissues around the m-HA/PEEK composites with an HA content of 5 wt.% is better than that of specimens with different HA contents. This finding shows the nano-scale effect of the bioactive filler HA in PEEK substrates, which obviously contributes to the growth of the surrounding bone issues in vivo. This study could provide theoretical support for the further promotion and application of high-performance engineering plastics such as PEEK in biomedical fields. - Highlight: • The modification of hydroxyapatite with KH-560 can increase the efficient dispersion of hydroxyapatite in PEEK substrates. • When the HA content is 5 wt. %, the tensile strength of modified-HA/PEEK composite reaches its maximum. • The nano-scale effect of HA fillers in PEEK substrates contributes to the growth of the

Fabrication and characterization of hydroxyapatite-coated forsterite ...

Indian Academy of Sciences (India)

... a novel hydroxyapatite (HA)-coated forsterite scaffold with a desired porous structure, high ... X-ray diffraction, scanning electron microscopy, transmission electron ... Dental Materials Research Center, Isfahan University of Medical Sciences, ...

Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

Energy Technology Data Exchange (ETDEWEB)

Chao, Shao Ching [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Department of Minimally Invasive Skull Neurosurgery, Neurological Institute, Taichung Veterans General Hospital, 1650 Taiwan Boulevard, Sect. 4, Taichung, Taiwan (China); Department of Neurosurgery, ChangHua Hospital, Ministry of Health and Welfare, 80 Chung Cheng Road, Sect. 2 Chiu Kuan Village, Changhua 500, Taiwan (China); Wang, Ming-Jia; Pai, Nai-Su [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Yen, Shiow-Kang, E-mail: skyen@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China)

2015-12-01

Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO{sub 3}){sub 2}, NH{sub 4}H{sub 2}PO{sub 4} and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space.

Preparation of hydroxyapatite nanoparticles facilitated by the presence of {beta}-cyclodextrin

Energy Technology Data Exchange (ETDEWEB)

Martinez-Perez, Carlos A., E-mail: camartin@uacj.mx [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Garcia-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, Jose R. [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Monreal Romero, Humberto [School of Odontology, Autonomous University of Chihuahua, UACH, Ave. Universidad s/n Campus Universitario I, C.P. 31170, Chihuahua (Mexico)

2012-09-25

Highlights: Black-Right-Pointing-Pointer It was found that {beta}-cyclodextrin can control the particle size in the production of nanohydroxyapatite. Black-Right-Pointing-Pointer Particle size in the range of 30-50 nm was obtained. Black-Right-Pointing-Pointer A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the {beta}-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20-50 nm. Also it was found that the content of {beta}-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

Preparation of hydroxyapatite nanoparticles facilitated by the presence of β-cyclodextrin

International Nuclear Information System (INIS)

Martínez-Pérez, Carlos A.; García-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, José R.; Monreal Romero, Humberto

2012-01-01

Highlights: ► It was found that β-cyclodextrin can control the particle size in the production of nanohydroxyapatite. ► Particle size in the range of 30–50 nm was obtained. ► A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the β-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20–50 nm. Also it was found that the content of β-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

Parente, P., E-mail: pparente@icv.csic.es [Instituto de Ceramica y Vidrio, CSIC, C/Kelsen 5, Madrid 28049 (Spain); Savoini, B. [Departamento de Fisica, Universidad Carlos III de Madrid, Avda. Universidad 30, Leganes 28911 (Spain); Ferrari, B. [Instituto de Ceramica y Vidrio, CSIC, C/Kelsen 5, Madrid 28049 (Spain); Monge, M.A.; Pareja, R. [Departamento de Fisica, Universidad Carlos III de Madrid, Avda. Universidad 30, Leganes 28911 (Spain); Sanchez-Herencia, A.J. [Instituto de Ceramica y Vidrio, CSIC, C/Kelsen 5, Madrid 28049 (Spain)

2013-03-01

The capability of the colloidal method to produce yttria (Y{sub 2}O{sub 3}) dispersed hydroxyapatite (HA) has been investigated as an alternative method to the conventional method of mechanical mixing and sintering for developing HA-based materials that could exhibit controllable and enhanced functional properties. A water based colloidal route to produce HA materials with highly dispersed Y{sub 2}O{sub 3} has been applied, and the effect of 10 wt.% Y{sub 2}O{sub 3} addition to HA investigated by thermal analysis, X-ray diffraction and Fourier transform infrared spectroscopy. These measurements evidence a remarkable effect of this Y{sub 2}O{sub 3} addition on decomposition mechanisms of synthetic HA. Results show that incorporation of Y{sub 2}O{sub 3} as dispersed second phase is beneficial because it hinders the decomposition mechanisms of HA into calcium phosphates. This retardation will allow the control of the sintering conditions for developing HA implants with improved properties. Besides, substitution of Ca{sup 2+} with Y{sup 3+} ions appears to promote the formation of OH{sup -} vacancies, which could improve the conductive properties of HA favorable to osseointegration. - Highlights: Black-Right-Pointing-Pointer We reveal the influence of Y{sub 2}O{sub 3} on thermal stability of hydroxyapatite. Black-Right-Pointing-Pointer Incorporation of Y{sub 2}O{sub 3} delays decomposition of hydroxyapatite to calcium phosphates. Black-Right-Pointing-Pointer Addition of Y{sub 2}O{sub 3} enables sintering conditions more favorable to the densification.

Synthesis of antimicrobial silver/hydroxyapatite nanocomposite by gamma irradiation

International Nuclear Information System (INIS)

Akhavan, A.; Sheikh, N.; Khoylou, F.; Naimian, F.; Ataeivarjovi, E.

2014-01-01

Silver nanoparticles (AgNPs) were synthesized through γ-irradiation reduction of silver ions into hydroxyapatite as a solid support. The formation of AgNPs incorporated in the hydroxyapatite composite was studied as a function of γ-irradiation doses. The X-ray diffraction and transmission electron microscopy (TEM) measurements showed the fabrication of face-centered cubic AgNPs with a mean diameter of about 39 nm at 20 kGy absorbed dose. When the absorbed dose increases from 20 to 40 kGy the size of AgNPs particles partially increases, while with increasing absorbed dose from 40 to 60 kGy the particle diameters decreases. In addition, the results of XRD analysis indicated that increasing of γ-irradiation doses from 20 to 40 kGy enhances the concentration of AgNPs, without inducing significant changes in degree of HA crystallinity. The antibacterial test study of samples against Escherichia coli indicated a significant enhancement in the antibacterial property of Ag/HA nanocomposites. - Highlights: • Silver/hydroxyapatite nanocomposites are synthesized through γ-irradiation method. • Ag/HA nanocomposites have good antibacterial properties. • Fabricated pure nanocomposites are suitable for medical and dental applications

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.

Design and fabrication of carbon fibers with needle-like nano-HA coating to reinforce granular nano-HA composites.

Science.gov (United States)

Wang, Xudong; Zhao, Xueni; Zhang, Li; Wang, Wanying; Zhang, Jing; He, Fuzhen; Yang, Jianjun

2017-08-01

Carbon fibers (CFs) with needle-like nano-hydroxyapatite (nHA) coating were first used as reinforcing materials named nHA-CFs to improve the mechanical properties of pure HA. A powder mixture containing nHA-CFs and granular nano-HA (gHA) was directly sintered by hot pressing at appropriate sintering pressure and temperature. A three-phase nHA-CFs/gHA composite was designed, fabricated, and used as an artificial bone. Results show that the bending strengths of the nHA-CFs/gHA composite are approximately 41.1% and 59.2% higher than those of CFs/gHA composite and pure HA, respectively. The possible reinforcing mechanism of nHA-CFs in the composite is also proposed at the end. When nHA-CFs are applied for preparation of nHA-CFs/gHA composites, the internal stress on its phase boundary with gHA matrix generated during cooling of sintered is significantly reduced due to the presence of the nHA coatings. It infers that nHA coatings on CFs might act as a bridge to control the forming of interfacial gaps between the gHA matrix and the CFs effectively. Our work provides additional insights into the feasibility of nHA-CFs/gHA composites as load-bearing implant materials in clinical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis of nanocrystalline fluorinated hydroxyapatite by ...

Indian Academy of Sciences (India)

The biological hydroxyapatite in the human bone and tooth is of nanosize and ... The crystal size and morphology of the nanopowders were examined by X-ray powder diffraction .... tal growth along the c axis of HA crystalline structure. The.

Fabrication of nanocrystalline hydroxyapatite doped degradable composite hollow fiber for guided and biomimetic bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zhang Ning [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Nichols, Heather L. [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Tylor, Shila [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Wen Xuejun [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States)]. E-mail: xjwen@clemson.edu

2007-04-15

Natural bone tissue possesses a nanocomposite structure interwoven in a three-dimensional (3-D) matrix, which plays critical roles in conferring appropriate physical and biological properties to the bone tissue. Single type of material may not be sufficient to mimic the composition, structure and properties of native bone, therefore, composite materials consisting of both polymers, bioceramics, and other inorganic materials have to be designed. Among a variety of candidate materials, polymer-nanoparticle composites appear most promising for bone tissue engineering applications because of superior mechanical properties, improved durability, and surface bioactivity when compared with conventional polymers or composites. The long term objective of this project is to use highly aligned, bioactive, biodegradable scaffold mimicking natural histological structure of human long bone, and to engineer and regenerate human long bone both in vitro and in vivo. In this study, bioactive, degradable, and highly permeable composite hollow fiber membranes (HFMs) were fabricated using a wet phase phase-inversion approach. The structure of the hollow fiber membranes was examined using scanning electron microscopy (SEM); degradation behavior was examined using weigh loss assay, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC); and bioactivity was evaluated with the amount of calcium deposition from the culture media onto HFM surface. Doping PLGA HFMs with nanoHA results in a more bioactive and slower degrading HFM than pure PLGA HFMs.

Hydroxyapatite synthesis and labelling with with Samarium-153

International Nuclear Information System (INIS)

Miranda, J.; Enciso, A.M.; Herrera, J.; Portilla, A.; Carrillo, D.

1999-01-01

153 Sm-labeled hydroxyapatite (HA) is used in synovectomy performed by radiation. HA was synthesized according to the method employed by Hayek and Newesely, using calcium nitrate and ammonium diacid phosphate in basic pH. Chemical characterization of HA was carried out by x-ray diffraction. HA labeling with Sm-153 is conducted using citric acid as ligand; radiochemical purity is greater than 99% and labeled particles are stable up to 9 days. This product is adequate to treat rheumatoid arthritis

Magnesium substituted hydroxyapatite formation on (Ti,Mg)N coatings produced by cathodic arc PVD technique

International Nuclear Information System (INIS)

Onder, Sakip; Kok, Fatma Nese; Kazmanli, Kursat; Urgen, Mustafa

2013-01-01

In this study, formation of magnesium substituted hydroxyapatite (Ca 10−x Mg x (PO 4 ) 6 (OH) 2 ) on (Ti,Mg)N and TiN coating surfaces were investigated. The (Ti 1−x ,Mg x )N (x = 0.064) coatings were deposited on titanium substrates by using cathodic arc physical vapor deposition technique. TiN coated grade 2 titanium substrates were used as reference to understand the role of magnesium on hydroxyapatite (HA) formation. The HA formation experiments was carried out in simulated body fluids (SBF) with three different concentrations (1X SBF, 5X SBF and 5X SBF without magnesium ions) at 37 °C. The coatings and hydroxyapatite films formed were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and FTIR Spectroscopy techniques. The energy dispersive X-ray spectroscopy (EDS) analyses and XRD investigations of the coatings indicated that magnesium was incorporated in the TiN structure rather than forming a separate phase. The comparison between the TiN and (Ti, Mg)N coatings showed that the presence of magnesium in TiN structure facilitated magnesium substituted HA formation on the surface. The (Ti,Mg)N coatings can potentially be used to accelerate the HA formation in vivo conditions without any prior hydroxyapatite coating procedure. - Highlights: • Mg incorporated in (Ti,Mg)N coating structure and did not form a separate phase • Mg dissolution in SBF solution facilitated Mg-substituted hydroxyapatite formation • (Ti,Mg)N acted as Mg-source for Mg-substituted hydroxyapatite formation in SBF

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.

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.

The electrolysis time on electrosynthesis of hydroxyapatite with bipolar membrane

Science.gov (United States)

Nur, Adrian; Jumari, Arif; Budiman, Anatta Wahyu; Puspitaningtyas, Stella Febianti; Cahyaningrum, Suci; Nazriati, Nazriati; Fajaroh, Fauziatul

2018-02-01

The electrochemical method with bipolar membrane has been successfully used for the synthesis of hydroxyapatite. In this work, we have developed 2 chambers electrolysis system separated by a bipolar membrane. The membrane was used to separate cations (H+ ions produced by the oxidation of water at the anode) and anions (OH- ions produced by the reduction of water at the cathode). With this system, we have designed that OH- ions still stay in the anions chamber because OH- ions was very substantial in the hydroxyapatite particles formation. The aim of this paper was to compare the electrolysis time on electrosynthesis of hydroxyapatite with and without the bipolar membrane. The electrosynthesis was performed at 500 mA/cm2 for 0.5 to 2 hours at room temperature and under ultrasonic cleaner to void agglomeration with and without the bipolar membrane. The electrosynthesis of hydroxyapatite with the bipolar membrane more effective than without the bipolar membrane. The hydroxyapatite has been appeared at 0.5 h of the electrolysis time with the bipolar membrane (at the cathode chamber) while it hasn't been seen without the bipolar membrane. The bipolar membrane prevents OH- ions migrate to the cation chamber. The formation of HA becomes more effective because OH- ions just formed HA particle.

Inhibition of hydroxyapatite growth by casein, a potential salivary phosphoprotein homologue.

Science.gov (United States)

Romero, Maria J R H; Nakashima, Syozi; Nikaido, Toru; Ichinose, Shizuko; Sadr, Alireza; Tagami, Junji

2015-08-01

Salivary phosphoproteins are essential in tooth mineral regulation but are often overlooked in vitro. This study aimed to evaluate the effect of casein, as a salivary phosphoprotein homologue, on the deposition and growth of hydroxyapatite (HA) on tooth surfaces. Hydroxyapatite growth was quantified using seeded crystal systems. Artificial saliva (AS) containing HA powder and 0, 10, 20, 50, or 100 μg ml(-1) of casein, or 100 μg ml(-1) of dephosphorylated casein (Dcasein), was incubated for 0-8 h at 37°C, pH 7.2. Calcium concentrations were measured using atomic absorption spectroscopy (AAS). Surface precipitation of HA on bovine enamel and dentine blocks, incubated in similar conditions for 7 d, was examined using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) with selected area electron diffraction (SAED). Casein adsorption was assessed using modified Lowry assays and zeta-potential measurements. The AAS results revealed a concentration-dependent inhibition of calcium consumption. Hydroxyapatite precipitation occurred when no casein was present, whereas precipitation of HA was apparently completely inhibited in casein-containing groups. Adsorption data demonstrated increasingly negative zeta-potential with increased casein concentration and an affinity constant similar to proline-rich proteins with Langmuir modelling. Casein inhibited the deposition and growth of HA primarily through the binding of esterized phosphate to HA active sites, indicating its potential as a mineral-regulating salivary phosphoprotein homologue in vitro. © 2015 Eur J Oral Sci.

Corrosion behavior of plasma sprayed hydroxyapatite and hydroxyapatite-silicon oxide coatings on AISI 304 for biomedical application

International Nuclear Information System (INIS)

Singh, Gurpreet; Singh, Hazoor; Sidhu, Buta Singh

2013-01-01

The objective of this study is to evaluate corrosion resistance of plasma sprayed hydroxyapatite (HA) and HA-silicon oxide (SiO 2 ) coated AISI 304 substrates. In HA-SiO 2 coatings, 10 wt% SiO 2 and 20 wt% SiO 2 was mixed with HA. The feedstock and coatings were characterized by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy. The corrosion resistance was determined for the uncoated and coated samples. The corrosion resistance of the AISI 304 was found more after the deposition of the HA-SiO 2 coatings rather than HA coating and uncoated. All the coatings were crack free after 24 h dipping in Ringer's solution for electrochemical corrosion testing.

Novel selenium-doped hydroxyapatite coatings for biomedical applications.

Science.gov (United States)

Rodríguez-Valencia, C; López-Álvarez, M; Cochón-Cores, B; Pereiro, I; Serra, J; González, P

2013-03-01

Nowadays there is a short-term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium-doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT-Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO(3)(2-) groups in the CO(3)(2-) sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3-E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms. Copyright © 2012 Wiley Periodicals, Inc.

Preparation and characterization of nano-hydroxyapatite within chitosan matrix

International Nuclear Information System (INIS)

Rogina, A.; Ivanković, M.; Ivanković, H.

2013-01-01

Nano-composites that show some features of natural bone both in composition and in microstructure have been prepared by in situ precipitation method. Apatite phase has been prepared from cost-effective precursors (calcite and urea phosphate) within chitosan (CS) matrix dissolved in aqueous acetic acid solution. The compositional and morphological properties of composites were studied by means of Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). Depending on the reaction conditions (temperature, reaction time, glucose addition and pH control) in addition to hydroxyapatite (HA) as a major phase, octacalcium hydrogen phosphate pentahydrate (OCP) and dicalcium phosphate anhydrate (DCPD) were formed as shown by XRD and FTIR. Crystallite lengths of precipitated HA estimated by Scherrer's equation were between 20 and 30 nm. A fibrous morphology (∼ 400 nm) of HA observed by TEM indicates that HA nucleates on chitosan chains. - Highlights: • Nano-hydroxyapatite (HA) was prepared by in situ precipitation within chitosan hydrogels and colloidal chitosan solution. • pH control was regulated by ammonia and urea degradation. • In situ urea degradation provides homogenous HA formation. • TEM imaging indicates fibrous morphology of HA with crystalline size of 400 nm. • Glucose addition and temperature variation affect inorganic phase formation

Direct growth of carbon nanotubes on hydroxyapatite using MPECVD

Energy Technology Data Exchange (ETDEWEB)

Duraia, El-Shazly M., E-mail: duraia_physics@yahoo.com [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Al-Farbi Kazakh National University, Almaty (Kazakhstan); Institute of Physics and Technology, Almaty (Kazakhstan); Texas State University-San Marcos, Department of Chemistry and Biochemistry, 601 University Dr., San Marcos, TX 78666 (United States); Hannora, A. [Suez Canal University, Faculty of Petroleum and Mining Engineering (Egypt); Mansurov, Z. [Al-Farbi Kazakh National University, Almaty (Kazakhstan); Beall, Gary W. [Texas State University-San Marcos, Department of Chemistry and Biochemistry, 601 University Dr., San Marcos, TX 78666 (United States)

2012-01-16

Graphical abstract: Carbon nanotubes have been grown directly on hydroxyapatite by using microwave plasma-enhanced chemical vapor deposition (MPECVD). Highlights: Black-Right-Pointing-Pointer CNTs have been successfully grown directly on hydroxyapatite using MPECVD. Black-Right-Pointing-Pointer Diameter distribution of the CNTs lies in the range from 30 to 70 nm. Black-Right-Pointing-Pointer The HA surface is partially transformed to {beta}-TCP during the deposition. Black-Right-Pointing-Pointer Grown CNTs have good quality and I{sub G}/I{sub D} ratio lies between 1.243 and 1.774. - Abstract: For the first time carbon nanotubes (CNTs) have been successfully grown directly on hydroxyapatite (HA) by using microwave plasma enhanced chemical vapor deposition (MPECVD). Such integration has potential to capitalize on the merits of both HA and CNTs. This type of coating could be useful to improve the interface between bone and the implant. Scanning electron microscope SEM investigations show that; the surface of the CNTs is relatively clean and free of amorphous carbon. The CNTs diameters lie in the range 30-70 nm. In addition HA encapsulation by carbon was observed at a growth temperature 750 Degree-Sign C. Raman spectroscopy indicates that the CNTs are of high quality and the I{sub G}/I{sub D} ratio lies between 1.243 and 1.774. The changes in the X-ray diffraction (XRD) patterns give an indication that during the plasma deposition the HA-substrate surface is subjected to a temperature sufficient for partial conversion to the {beta}-tricalcium phosphate via dehydroxylation.

Surface modification of hydroxyapatite nanoparticles by poly(L-phenylalanine) via ROP of L-phenylalanine N-carboxyanhydride (Pha-NCA)

International Nuclear Information System (INIS)

Dai Yanfeng; Xu Min; Wei Junchao; Zhang Haobin; Chen Yiwang

2012-01-01

The surface of hydroxyapatite nanoparticles was modified by poly(L-phenylalanine) via the ring opening polymerization (ROP) of L-phenylalanine N-carboxyanhydride. The preparation procedure was monitored by Fourier transform infrared spectroscopy (FTIR), and the modified hydroxyapatite was characterized by thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). The results showed that the surface grafting amounts of poly(L-phenylalanine) on HA ranging from 20.26% to 38.92% can be achieved by tuning the reaction condition. The XRD patterns demonstrated that the crystalline structure of the modified hydroxyapatite was nearly the same with that of HA, implying that the ROP was an efficient surface modification method. The MTT assay proved that the biocompatibility of modified HA was very good, which showed the potential application of modified HA in bone tissue engineering.

Porous HA-Al2O3 composite characterization using corn starch as a porogen agent

International Nuclear Information System (INIS)

Silva, L.A.J. da; Galdino, A.G.S.; Cardoso, G.B.C.; Zavaglia, C.A.C.

2011-01-01

The porous ceramics based on hydroxyapatite have great potential for application in bone grafts due to its chemical similarity with the mineral phase of bone tissue, but have poor biomechanical properties, which cause limitations in its applications. This work aims to analyze the structural characteristics of porous ceramics obtained by addition of hydroxyapatite (HA, sintered in the laboratory), Corn Starch (CS, commercial) and Al 2 O 3 (ALCOA), at different temperatures. Samples were made of dense HA (100% HA), porous (70% HA - 30% CS) and with addition of 2.5%, 5% and 7.5% Al 2 O 3 porous composition. The samples were sintered at 1250°C, 1300 deg C and 135 0°C and characterized by: XRF, XRD, SEM and density by the Archimedes method. Concludes It is the possibility of obtaining samples porous HA / Al 2 O 3 using starch as porogenic agent. The temperature and concentration of Al 2 O 3 most appropriate were: 1250°C and 7.5%. (author)

Novel doped hydroxyapatite thin films obtained by pulsed laser deposition

International Nuclear Information System (INIS)

Duta, L.; Oktar, F.N.; Stan, G.E.; Popescu-Pelin, G.; Serban, N.; Luculescu, C.; Mihailescu, I.N.

2013-01-01

Highlights: ► HA coatings synthesized by pulsed laser deposition. ► Comparative study of commercial vs. animal origin materials. ► HA coatings of animal origin were rougher and more adherent to substrates. ► Animal origin films can be considered as promising candidates for implant coatings. - Abstract: We report on the synthesis of novel ovine and bovine derived hydroxyapatite thin films on titanium substrates by pulsed laser deposition for a new generation of implants. The calcination treatment applied to produce the hydroxyapatite powders from ovine/bovine bones was intended to induce crystallization and to prohibit the transmission of diseases. The deposited films were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Pull-off adherence and profilometry measurements were also carried out. X-ray diffraction ascertained the polycrystalline hydroxyapatite nature of the powders and films. Fourier transform infrared spectroscopy evidenced the vibrational bands characteristic to a hydroxyapatite material slightly carbonated. The micrographs of the films showed a uniform distribution of spheroidal particulates with a mean diameter of ∼2 μm. Pull-off measurements demonstrated excellent bonding strength values between the hydroxyapatite films and the titanium substrates. Because of their physical–chemical properties and low cost fabrication from renewable resources, we think that these new coating materials could be considered as a prospective competitor to synthetic hydroxyapatite used for implantology applications.

Monodisperse selenium-substituted hydroxyapatite: Controllable synthesis and biocompatibility

Energy Technology Data Exchange (ETDEWEB)

Sun, Jianpeng [School of Civil Engineering, Xi' an University of Architecture and Technology, Shaanxi 710055 (China); 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 (China); Zheng, Xiaoyan; Li, Hui; Fan, Daidi [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 (China); Song, Zhanping [School of Civil Engineering, Xi' an University of Architecture and Technology, Shaanxi 710055 (China); Ma, Haixia [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 (China); Hua, Xiufu, E-mail: hua_xiufu@163.com [Department of Scientific Research and Development, Tsinghua University, Beijing 100084 (China); Hui, Junfeng, E-mail: huijunfeng@126.com [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 (China)

2017-04-01

Hydroxyapatite (HA) is the major inorganic component of natural bone tissue. As an essential trace element, selenium involves in antioxidation and anticancer of human body. So far, ion-doped hydroxyapatites (HAs) are widely investigated owing to their great applications in field of biomaterial, biological labeling. In this paper, series of monodisperse HA doped with SeO{sub 3}{sup 2−} (SeHA) was successfully synthesized based on the liquid–solid–solution (LSS) strategy. The obtained samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive spectrometer (EDS). The results indicated that the SeO{sub 3}{sup 2−} doping level of the Se/(P + Se) molar ratio of 0– 0.4 can be requisitely controlled, and the morphology of SeHA nanoparticles varied from nanorods to nanoneedles with increasing Se/(P + Se) molar ratio. Significantly, the as-synthesized SeHA nanocrystals exhibit a low cytotoxicity for osteoblastic cells, showing exciting potentials for application in artificial scaffold materials inhibiting of tumor growth in bone. - Highlights: • Series of SeO{sub 3}{sup 2−} doped HA nanorods or/and nanoneedles were successfully synthesized. • The morphology of the HA nanocrystals can be easily controlled by changing the Se/(P + Se) molar ratio. • The as-synthesized SeHA nanocrystals exhibit a low cytotoxicity for osteoblastic cells. • Showing exciting potentials for application in artificial scaffold materials inhibiting of tumor growth in bone.

Monodisperse selenium-substituted hydroxyapatite: Controllable synthesis and biocompatibility

International Nuclear Information System (INIS)

Sun, Jianpeng; Zheng, Xiaoyan; Li, Hui; Fan, Daidi; Song, Zhanping; Ma, Haixia; Hua, Xiufu; Hui, Junfeng

2017-01-01

Hydroxyapatite (HA) is the major inorganic component of natural bone tissue. As an essential trace element, selenium involves in antioxidation and anticancer of human body. So far, ion-doped hydroxyapatites (HAs) are widely investigated owing to their great applications in field of biomaterial, biological labeling. In this paper, series of monodisperse HA doped with SeO 3 2− (SeHA) was successfully synthesized based on the liquid–solid–solution (LSS) strategy. The obtained samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive spectrometer (EDS). The results indicated that the SeO 3 2− doping level of the Se/(P + Se) molar ratio of 0– 0.4 can be requisitely controlled, and the morphology of SeHA nanoparticles varied from nanorods to nanoneedles with increasing Se/(P + Se) molar ratio. Significantly, the as-synthesized SeHA nanocrystals exhibit a low cytotoxicity for osteoblastic cells, showing exciting potentials for application in artificial scaffold materials inhibiting of tumor growth in bone. - Highlights: • Series of SeO 3 2− doped HA nanorods or/and nanoneedles were successfully synthesized. • The morphology of the HA nanocrystals can be easily controlled by changing the Se/(P + Se) molar ratio. • The as-synthesized SeHA nanocrystals exhibit a low cytotoxicity for osteoblastic cells. • Showing exciting potentials for application in artificial scaffold materials inhibiting of tumor growth in bone

Preparation and biological behaviour of samarium-153-hydroxyapatite particles for radiation synovectomy

International Nuclear Information System (INIS)

Agrueelles, M.G.; Luppi Berlanga, I.S.; Torres, E.A.; Rutty Sola, G.A.; Rimoldi, G.

1998-01-01

The preparation and labelling procedures of 153 Sm-hydroxyapatite ( 153 Sm-HA) are described in this paper. Hydroxyapatite (HA) was prepared and studied as a radiosynovectomy agent. HA particles were prepared from the reaction of calcium nitrate and ammonia phosphate at high pH Samarium-153 labelling was done in two steps with citric acid. A serie of experimental conditions, such as specific activity, citric acid mass, radioactive solution volume, in-vitro stability, have been carried out. Radiolabelling efficiency was greater than 95%. In vitro studies showed high stability (≥99%). Animal studies showed a good retention in the synovium, with a very low extra-articular leakage over 6 days after administration. (author)

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)

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.

Magnesium substituted hydroxyapatite formation on (Ti,Mg)N coatings produced by cathodic arc PVD technique.

Science.gov (United States)

Onder, Sakip; Kok, Fatma Nese; Kazmanli, Kursat; Urgen, Mustafa

2013-10-01

In this study, formation of magnesium substituted hydroxyapatite (Ca10-xMgx(PO4)6(OH)2) on (Ti,Mg)N and TiN coating surfaces were investigated. The (Ti1-x,Mgx)N (x=0.064) coatings were deposited on titanium substrates by using cathodic arc physical vapor deposition technique. TiN coated grade 2 titanium substrates were used as reference to understand the role of magnesium on hydroxyapatite (HA) formation. The HA formation experiments was carried out in simulated body fluids (SBF) with three different concentrations (1X SBF, 5X SBF and 5X SBF without magnesium ions) at 37 °C. The coatings and hydroxyapatite films formed were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and FTIR Spectroscopy techniques. The energy dispersive X-ray spectroscopy (EDS) analyses and XRD investigations of the coatings indicated that magnesium was incorporated in the TiN structure rather than forming a separate phase. The comparison between the TiN and (Ti, Mg)N coatings showed that the presence of magnesium in TiN structure facilitated magnesium substituted HA formation on the surface. The (Ti,Mg)N coatings can potentially be used to accelerate the HA formation in vivo conditions without any prior hydroxyapatite coating procedure. © 2013.

Synthesis, characterization and biocompatibility evaluation of hydroxyapatite - gelatin polyLactic acid ternary nanocomposite

Directory of Open Access Journals (Sweden)

Z. Nabipour

2016-04-01

Full Text Available Objective(s: The current study reports the production and biocompatibility evaluation of a ternary nanocomposite consisting of HA, PLA, and gelatin for biomedical application.Materials and Methods: Hydroxyapatite nanopowder (HA: Ca10(PO46(OH2 was produced by burning the bovine cortical bone within the temperature range of 350-450 oC followed by heating in an oven at 800. Synthesis of the ternary nanocomposite was carried out in two steps: synthesis of gelatin-hydroxyapatite binary nanocomposite and addition of poly lactic acid with different percentages to the resulting composition. The crystal structure was determined by X-ray diffraction (XRD, while major elements and impurities of hydroxyapatite were identified by elemental analysis of X-ray fluorescence (XRF. Functional groups were determined by Fourier transform infrared spectroscopy (FTIR. Morphology and size of the nanocomposites were evaluated using field emission scanning electron microscope (FE-SEM.Biocompatibility of nanocomposites was investigated by MTT assay. Results: XRD patterns verified the ideal crystal structure of the hydroxyapatite, which indicated an appropriate synthesis process and absence of disturbing phases. Results of FTIR analysis determined the polymers’ functional groups, specified formation of the polymers on the hydroxyapatite surface, and verified synthesis of nHA/PLA/Gel composite. FESEM images also indicated the homogeneous structure of the composite in the range of 50 nanometers. MTT assay results confirmed the biocompatibility of nanocomposite samples.Conclusion: This study suggested that the ternary nanocomposite of nHA/PLA/Gel can be a good candidate for biomedical application such as drug delivery systems, but for evaluation of its potential in hard tissue replacement, mechanical tests should be performed.

Influences of magnetized hydroxyapatite on the growth behaviors of osteoblasts and the mechanism from molecular dynamics simulation

International Nuclear Information System (INIS)

Yang, Weihu; Xi, Xingfeng; Fang, Jiajia; Liu, Peng; Cai, Kaiyong

2013-01-01

To investigate the influence of magnetized hydroxyapatite on the growth and differentiation of osteoblasts, hydroxyapatite (HA) and magnetized hydroxyapatite (mHA) were synthesized and characterized. The cell viability, differentiation, and morphologies of osteoblasts were investigated in vitro, respectively. The results showed that compared to HA, cells cultured with mHA had better cell viability, and both HA and mHA were beneficial to the early differentiation of osteoblasts. Furthermore, the interaction mechanism between mHA and osteoblasts was elucidated using a molecular dynamics simulation. The simulation results indicated that when cultured with osteoblasts, HA adsorbed bovine serum protein onto its surface from the medium immediately, which was beneficial to the adhesion and proliferation of osteoblasts. The main driving force for the adsorption of bovine serum was the electronic properties of HA crystal faces. The (211) crystal face of HA had the highest electron density among its all crystal faces, thus mainly contributing to the protein adsorption of HA. Nevertheless, the (211) crystal face of mHA still had a relatively higher electron density than that of HA, thus possessing better protein adsorption than that of HA, and in turn promoting the biological functions of osteoblasts. - Highlights: • Both HA and magnetized HA were beneficial for the early osteogenesis of osteoblasts. • Magnetized HA had better cell viability than HA. • The HA–protein interaction mechanism was investigated by computation simulation. • The main driving force for protein adsorption came from the electronic properties. • The (211) face of mHA has higher electron density and better biological functions

Bio resorbability of the modified hydroxyapatite in Tris-HCL buffer

International Nuclear Information System (INIS)

Golovanova, O A; Izmailov, R R; Ghyngazov, S A

2016-01-01

The solubility of carbonated hydroxyapatite powders and granulated carbonated hydroxyapatite produced from the synovial biofluid model solution has been studied. The kinetic characteristics of dissolution were determined. It was found that the solubility of carbonated hydroxyapatite is higher as compared to that of hydroxyapatite. The impact of the organic matrix on the rate of sample dissolution was revealed. For HA-gelatin composites, as the gelatin concentration grows, the dissolution rate becomes greater, and a sample of 6.0 g / L concentration has higher resorbability. The results of the research can be used to study the kinetics of dissolution and the biocompatibility of ceramic materials for medicine, namely for reconstructive surgery, dentistry, and development of drug delivery systems. (paper)

Mechanical properties of natural chitosan/hydroxyapatite/magnetite nanocomposites for tissue engineering applications

Energy Technology Data Exchange (ETDEWEB)

Heidari, Fatemeh [Department of Materials Science and Engineering, School of Engineering, Yasouj University, Yasuj 75918-74934 (Iran, Islamic Republic of); Razavi, Mehdi [BCAST, Institute of Materials and Manufacturing, Brunel University London, Uxbridge, London UB8 3PH (United Kingdom); Brunel Institute for Bioengineering, Brunel University London, Uxbridge, London UB8 3PH (United Kingdom); Bahrololoom, Mohammad E. [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Bazargan-Lari, Reza [Department of Materials Science and Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht (Iran, Islamic Republic of); Vashaee, Daryoosh [Electrical and Computer Engineering Department, North Carolina State University, Raleigh, NC 27606 (United States); Kotturi, Hari [Department of Biology, University of Central Oklahoma, Edmond, OK 73034 (United States); Tayebi, Lobat, E-mail: lobat.tayebi@marquette.edu [Department of Developmental Sciences, Marquette University School of Dentistry, Milwaukee, WI 53233 (United States); Department of Engineering Science, University of Oxford, Oxford OX1 3PJ (United Kingdom)

2016-08-01

Chitosan (CS), hydroxyapatite (HA), and magnetite (Fe{sub 3}O{sub 4}) have been broadly employed for bone treatment applications. Having a hybrid biomaterial composed of the aforementioned constituents not only accumulates the useful characteristics of each component, but also provides outstanding composite properties. In the present research, mechanical properties of pure CS, CS/HA, CS/HA/magnetite, and CS/magnetite were evaluated by the measurements of bending strength, elastic modulus, compressive strength and hardness values. Moreover, the morphology of the bending fracture surfaces were characterized using a scanning electron microscope (SEM) and an image analyzer. Studies were also conducted to examine the biological response of the human Mesenchymal Stem Cells (hMSCs) on different composites. We conclude that, although all of these composites possess in-vitro biocompatibility, adding hydroxyapatite and magnetite to the chitosan matrix can noticeably enhance the mechanical properties of the pure chitosan. - Highlights: • Chitosan (CS)/magnetite composite presented the maximum bending strength. • Adding hydroxyapatite and magnetite to the CS enhances its mechanical properties. • Magnetic does not have reverse effect on the cyto-compatibility of samples.

Stoichiometric hydroxyapatite obtained by precipitation and sol gel processes

Energy Technology Data Exchange (ETDEWEB)

Guzman V, C.; Pina B, C.; Munguia, N. [IIM-UNAM, A.P. 70-360, 04510 Mexico D.F. (Mexico)]. e-mail: caroguz@servidor.unam.mx

2005-07-01

Three methods for obtaining hydroxyapatite (HA) are described. HA is a very interesting ceramic because of its many medical applications. The first two precipitation methods start from calcium and phosphorous compounds, whereas the third method is a sol-gel process that uses alkoxides. The products were characterized and compared. The observed differences are important for practical applications. (Author)

Preparation of bioactive porous HA/PCL composite scaffolds

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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.

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

Hydroxyapatite-alginate nanocomposite as drug delivery matrix for sustained release of ciprofloxacin.

Science.gov (United States)

Venkatasubbu, G Devanand; Ramasamy, S; Ramakrishnan, V; Kumar, J

2011-12-01

Hydroxyapatite is a bioceramic which has a wide range of medical application for bone diseases. To enhance its usage, we have prepared ciprofloxacin loaded nano hydroxyapatite (HA) composite with a natural polymer, alginate, using wet chemical method at low temperature. The prepared composites were analyzed by various physicochemical methods. The results show that the nano HA crystallites are well intact with the alginate macromolecules. For the composite system FT-IR and micro Raman results are reported in this paper. Studies on the drug loading and drug release have been done. The drug is pre-adsorbed onto the ceramic particle before the formation of composite. The thermal behavior of composite has been studied using thermo gravimetric analysis (TGA). This work, reports that the nanocomposite prepared under optimum condition could prolong the release of ciprofloxacin compared with the ciprofloxacin loaded hydroxyapatite.

Characterisation and corrosion resistance of the electrodeposited hydroxyapatite and bovine serum albumin/hydroxyapatite films on Ti-6Al-4V-1Zr alloy surface

International Nuclear Information System (INIS)

Vasilescu, C.; Drob, P.; Vasilescu, E.; Demetrescu, I.; Ionita, D.; Prodana, M.; Drob, S.I.

2011-01-01

Graphical abstract: Display Omitted Research highlights: → EIS spectra for Ti6Al4V1Zr alloy were fitted with one time constant electric equivalent circuit. → For covered alloy the equivalent circuit contains two time constants. → Resistances of films increased in time revealing the improvement of the alloy protection capacity. → Surface roughness significantly increased by apatite formation, being favourably to cell adhesion. - Abstract: A new titanium base Ti-6Al-4V-1Zr alloy covered with hydroxyapatite or bovine serum albumin/hydroxyapatite was characterized in this paper in order to be used as implant material. Following techniques were used: linear polarization, electrochemical impedance spectroscopy, scanning electronic microscopy, Fourier transform infrared spectroscopy and atomic force microscopy. For HA or BSA/HA covered alloy, the electric equivalent circuit contains two time constants (for the passive film and for coatings). The resistance of the protective films increased in time and BSA/HA coating was slightly rougher than HA coating, this situation being favourably to the cell adhesion.

Characterisation and corrosion resistance of the electrodeposited hydroxyapatite and bovine serum albumin/hydroxyapatite films on Ti-6Al-4V-1Zr alloy surface

Energy Technology Data Exchange (ETDEWEB)

Vasilescu, C.; Drob, P. [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania); Vasilescu, E., E-mail: ec_vasilescu@yahoo.co [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania); Demetrescu, I.; Ionita, D.; Prodana, M. [Politehnica University of Bucharest, Faculty of Applied Chemistry and Material Science, Str. Polizu 1-7, 011061 Bucharest (Romania); Drob, S.I. [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania)

2011-03-15

Graphical abstract: Display Omitted Research highlights: {yields} EIS spectra for Ti6Al4V1Zr alloy were fitted with one time constant electric equivalent circuit. {yields} For covered alloy the equivalent circuit contains two time constants. {yields} Resistances of films increased in time revealing the improvement of the alloy protection capacity. {yields} Surface roughness significantly increased by apatite formation, being favourably to cell adhesion. - Abstract: A new titanium base Ti-6Al-4V-1Zr alloy covered with hydroxyapatite or bovine serum albumin/hydroxyapatite was characterized in this paper in order to be used as implant material. Following techniques were used: linear polarization, electrochemical impedance spectroscopy, scanning electronic microscopy, Fourier transform infrared spectroscopy and atomic force microscopy. For HA or BSA/HA covered alloy, the electric equivalent circuit contains two time constants (for the passive film and for coatings). The resistance of the protective films increased in time and BSA/HA coating was slightly rougher than HA coating, this situation being favourably to the cell adhesion.

Biomaterials recycling: bioglasses obtained from reuse of hydroxyapatite (HA) bovine bone with term exceeded validity; Reciclagem de biomateriais: biovidros obtidos a partir do reaproveitamento de hidroxiapatita (HA) ossea bovina com prazo de validade excedido

Energy Technology Data Exchange (ETDEWEB)

Silva, A.C.; Santos, S.C.; Braga, F.J.C., E-mail: dasilva.ac@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Aparecida, A.H. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Inst. de Quimica

2012-07-01

The hydroxyapatite (HA) is a reference bioceramic for bone replacement and regeneration medical practice, becoming one of the most produced and researched bone graft material. Since it is a material for biomedical application, the manufacture and storage of this bioceramic must comply with severe conservation criteria, and its validity date is the lawful major factor for disposal. Materials with the exceeded expiration date are usually discarded and incinerated, resulting in ash, environmental contamination and energy expenditure. This study evaluates the possibility of reuse of bovine HA collected after its validity date as raw material to obtain bioglass, aiming to natural resources saving and environmental emissions mitigation. 45S5 similar compositions were obtained by melting the materials at 1500 ° C, followed by rapid cooling and annealing thermal treatment (500 ° C for 2h), analytical grade chemical reagents were used to set the final composition. The obtained materials were characterized by X-ray diffraction, infrared spectroscopy (FT-IR), and hydrolysis resistance techniques. The results of comparative chemical resistance (Hydrolytic) tests indicate the potential use of the materials developed for bone replacement applications. (author)

Improved mechanical properties of hydroxyapatite whisker-reinforced poly(L-lactic acid) scaffold by surface modification of hydroxyapatite.

Science.gov (United States)

Fang, Zhou; Feng, Qingling

2014-02-01

To improve the mechanical properties of porous hydroxyapatite/poly(L-lactic acid) (HA/PLLA) composites, HA whiskers with high crystallinity and high aspect ratio were synthesized. HA whiskers were modified with γ-aminopropyltriethoxysilane (APTES) to improve the interface between HA whiskers and PLLA. The composite scaffold consists of a porous PLLA matrix with HA whiskers distributed homogeneously. The morphology and the distributions of pore sizes of PLLA scaffold was not influenced by introducing HA whiskers, while the mechanical properties were improved. Both the compressive strength and compressive modulus were increased with the weight ratio of APTES-modified HA whiskers up to 30 wt.%, but only up to 15 wt.% for non-modified HA whiskers. With more than 15 wt.% HA whiskers, the mechanical properties of HA/PLLA scaffold were better improved with APTES-modified HA whiskers than non-modified. The HA whisker/PLLA scaffold with high porosity and improved mechanical properties is attractive in the application of tissue engineering. Copyright © 2013 Elsevier B.V. All rights reserved.

Adhesive strength of hydroxyl apatite(HA coating and biomechanics behavior of HA-coated prosthesis:an experimental study

Directory of Open Access Journals (Sweden)

Tian-yang ZHANG

2011-05-01

Full Text Available Objective To explore the influence of adhesive strength of hydroxyapatite(HA coating on the post-implantation stability of HA-coated prosthesis.Methods The adhesive strength and biomechanics behavior of HA coating were studied by histopathological observation,material parameters and biomechanical testing,the titanium(Ti-coated prosthesis was employed as control.Results Scratch test showed that the adhesive strength of HA coating was significantly lower than that of Ti coating(P < 0.01.Histopathological examination and bone morphometry showed that,at the early stage of prosthesis implantation,the bony growth around HA-coated prosthesis was significantly higher than that around Ti-coated prosthesis(P < 0.01,but the ultimate shear strength of HA-coated prosthesis was much lower than that of Ti-coated prosthesis(P < 0.01.After the push-out test with prosthesis,histopathological observation showed that there were accumulations of clump-and strip-like granular residues on the surface of bones that newly grew around the HA-coated prosthesis,and surface energy-dispersive X-ray spectroscopy(EDX analysis also confirmed that the shear stress induced HA decohesion from the substrate of prosthesis.Conclusions Although HA coating showed a satisfactory effect on early bone formation and prosthetic stability,due to the deficiencies of adhesive strength,the early stability of prosthesis may be gradually destroyed by the shear loads of human body and coating degradation.

Characterisation of Suspension Precipitated Nanocrystalline Hydroxyapatite Powders

International Nuclear Information System (INIS)

Mallik, P K; Swain, P.K.; Patnaik, S.C

2016-01-01

Hydroxyapatite (HA) is a well-known biomaterial for coating on femoral implants, filling of dental cavity and scaffold for tissue replacement. Hydroxyapatite possess limited load bearing capacity due to their brittleness. In this paper, the synthesis of nanocrystalline hydroxyapatite powders was prepared by dissolving calcium oxide in phosphoric acid, followed by addition of ammonia liquor in a beaker. The prepared solution was stirred by using magnetic stirrer operated at temperature of 80°C for an hour. This leads to the formation of hydroxyapatite precipitate. The precipitate was dried in oven for overnight at 100°C. The dried agglomerated precipitate was calcined at 800°C in conventional furnace for an hour. The influence of calcium oxide concentration and pH on the resulting precipitates was studied using BET, XRD and SEM. As result, a well-defined sub-rounded morphology of powders size of ∼41 nm was obtained with a salt concentration of 0.02 M. Finally, it can be concluded that small changes in the reaction conditions led to large changes in final size, shape and degree of aggregation of the hydroxyapatite particles. (paper)

Removal of Uranium in Drinking Water: Brimac Environmental Services, Inc. Brimac HA 216 Adsorptive Media

Science.gov (United States)

The Brimac HA 216 Adsorptive Media was tested for uranium (U) removal from a drinking water source (well water) at Grappone Toyota located in Bow, New Hampshire. The HA 216 media is a hydroxyapatite-based material. A pilot unit, consisting of a TIGG Corporation Cansorb® C-5 ste...

Electrophoretic Deposition of Hydroxyapatite Film Containing Re-Doped MoS₂ Nanoparticles.

Science.gov (United States)

Shalom, Hila; Feldman, Yishay; Rosentsveig, Rita; Pinkas, Iddo; Kaplan-Ashiri, Ifat; Moshkovich, Alexey; Perfilyev, Vladislav; Rapoport, Lev; Tenne, Reshef

2018-02-26

Films combining hydroxyapatite (HA) with minute amounts (ca. 1 weight %) of (rhenium doped) fullerene-like MoS₂ (IF) nanoparticles were deposited onto porous titanium substrate through electrophoretic process (EPD). The films were analyzed by scanning electron microscopy (SEM), X-ray diffraction and Raman spectroscopy. The SEM analysis showed relatively uniform coatings of the HA + IF on the titanium substrate. Chemical composition analysis using energy dispersive X-ray spectroscopy (EDS) of the coatings revealed the presence of calcium phosphate minerals like hydroxyapatite, as a majority phase. Tribological tests were undertaken showing that the IF nanoparticles endow the HA film very low friction and wear characteristics. Such films could be of interest for various medical technologies. Means for improving the adhesion of the film to the underlying substrate and its fracture toughness, without compromising its biocompatibility are discussed at the end.

[Remediation Pb, Cd contaminated soil in lead-zinc mining areas by hydroxyapatite and potassium chloride composites].

Science.gov (United States)

Wang, Li; Li, Yong-Hua; Ji, Yan-Fang; Yang, Lin-Sheng; Li, Hai-Rong; Zhang, Xiu-Wu; Yu, Jiang-Ping

2011-07-01

The composite agents containing potassium chloride (KCl) and Hydroxyapatite (HA) were used to remediate the lead and cadmium contaminated soil in Fenghuang lead-zinc mining-smelting areas, Hunan province. The objective of this study was to identify and evaluate the influence of Cl- to the fixing efficiency of Pb and Cd by HA. Two types of contaminated soil (HF-1, HF-2) were chosen and forty treatments were set by five different Hydroxyapatite (HA) dosages and four different Cl- dosages. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the results. It showed that HA could efficiently fix the Pb and Cd from TCLP form. The maximum Pb-fixing efficiency and Cd-fixing efficiency of two types of soil were 83.3%, 97.27% and 35.96%, 57.82% when the HA: Pb: KCl molar ratio was 8: 1: 2. Compared to the fixing efficiency without KCl, KCl at the KCl: Pb molar ratio of 2 improved Pb-fixing efficiency and Cd-fixing efficiency by 6.26%, 0.33% and 7.74%, 0.83% respectively when the HA: Pb molar ratio was 8. Generally, Cl- can improve the Pb/Cd-fixing efficiency in heavy metal contaminated soil by Hydroxyapatite.

Radiolabeling hydroxyapatite nanorods as theranostic agents for osteosarcoma and bone metastases

International Nuclear Information System (INIS)

Cipreste, Marcelo Fernandes

2017-01-01

The theranostic nanobiomaterials have received much attention of the scientific community around the world since these materials can accumulate spontaneously and selectively in tumor regions, being internalized by its cells and promoting simultaneously the diagnosis and the treatment of many types of cancer. Among many nanobiomaterials able to act as theranostic systems, hydroxyapatite nanorods (HA) stand up as promising theranostic agents to act in the early stages of osteosarcoma due to their important properties such as biocompatibility, bioactivity and high affinity to bone tissues, being able to act as drug delivery systems and radioisotopes carries, among many others biomedical applications. Apatite structures such as HA have high stability and flexibility that make them susceptible to the doping process and the conjugation with other crystallographic phases to confer theranostic properties to the material. However, the performance of these materials depends directly on the ability of these nanoparticles to bind to tumor cells. The process of surface functionalization of hydroxyapatite improves the adhesion of this material to the cell membranes. An important property acquired by hydroxyapatite functionalized with folic acid refers to the active and preferential accumulation in tumor sites of osteosarcoma. The present work consists in the investigation of theranostic systems through the synthesis of hydroxyapatite nanorods doped with gadolinium and copper, and functionalized with folic acid (FA). The process of neutron activation enabled the production of the radioisotopes 32 P, 159 Gd and 64 Cu in the HA lattice. A systematic study of the morphological and physicochemical characteristics was carried out, as well as the characterization of the magnetic and structural properties of these samples, including a study on the chemical interaction between folic acid, gadolinium, tenorite and the surface of nanoparticles. The synthesized materials were characterized

Synthesis, characterization and cell behavior of fluoridated hydroxyapatite

Science.gov (United States)

Qu, Haibo

Fluorine-containing hydroxyapatite (Ca5(PO4) 3(OH)1-xFx FHA), where F- partially replaces OH- in hydroxyapatite (HA), is recognized as a possible biomaterial for bone and tooth implants and gaining attention in the last several years as a possible alternative to HA. In this study, FHA powders were synthesized through a pH-cycling method. It was discovered that fluorine incorporation increased with the fluorine content in the initial solution and the number of pH cycles employed. A relatively low fluorine incorporation efficiency, ˜60%, was attained for most of the FHA samples. The short time of stay at each pH cycle and the limited number of cycles used are believed to be the main reasons of the low fluorine incorporation into the apatite structure. It was also revealed that the FHA particles produced by the pH-cycling method were inhomogeneous. They were a mixture of hydroxyapatite and F-rich apatite (or FA) particles. The mechanisms of incorporation of fluorine ions into hydroxyapatite by a pH cyclicing method were studied using TEM, XRD and fluorine measurement. Instead of forming laminated structures as reported by other research groups, a mixture of nano-sized F-rich apatite (FHA) and hydroxyapatite (HA) particles were obtained using the pH-cyclicing method. After calcination, these FHA particles were homogenized and became single phased FHA. The effect of fluorine content, preparing method, and sintering temperature on both the bulk density and biaxial flexural strength of sintered FHA was studied. Both uniaxially pressed un-milled (UPU) and cold isostatically pressed milled (IPM) FHA discs were sintered at temperatures between 1200˜400°C at an interval of 100°C. It was found that the fluorine content had a significant impact on the sintering behavior, densification, and mechanical properties of FHA discs. A close correlation between the sintered density and biaxial flexural strength of the specimens was revealed, where the biaxial flexural strength

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.

Effect of Water-Glass Coating on HA and HA-TCP Samples for MSCs Adhesion, Proliferation, and Differentiation

Directory of Open Access Journals (Sweden)

Indu Bajpai

2016-01-01

Full Text Available Ca-P and silicon based materials have become very popular as bone tissue engineering materials. In this study, water-glass (also known as sodium silicate glass was coated on sintered hydroxyapatite (HA and HA-TCP (TCP stands for tricalcium phosphate samples and subsequently heat-treated at 600°C for 2 hrs. X-rays diffraction showed the presence of β- and α-TCP phases along with HA in the HA-TCP samples. Samples without coating, with water-glass coating, and heat-treated after water-glass coating were used to observe the adhesion and proliferation response of bone marrow derived-mesenchymal stem cells (MSCs. Cell culture was carried out for 4 hrs, 1 day, and 7 days. Interestingly, all samples showed similar response for cell adhesion and proliferation up to 7-day culture but fibronectin, E-cadherin, and osteogenic differentiation related genes (osteocalcin and osteopontin were significantly induced in heat-treated water-glass coated HA-TCP samples. A water-glass coating on Ca-P samples was not found to influence the cell proliferation response significantly but activated some extracellular matrix genes and induced osteogenic differentiation in the MSCs.

Nanocrystallinity effects on osteoblast and osteoclast response to silicon substituted hydroxyapatite.

Science.gov (United States)

Casarrubios, Laura; Matesanz, María Concepción; Sánchez-Salcedo, Sandra; Arcos, Daniel; Vallet-Regí, María; Portolés, María Teresa

2016-11-15

Silicon substituted hydroxyapatites (SiHA) are highly crystalline bioceramics treated at high temperatures (about 1200°C) which have been approved for clinical use with spinal, orthopedic, periodontal, oral and craniomaxillofacial applications. The preparation of SiHA with lower temperature methods (about 700°C) provides nanocrystalline SiHA (nano-SiHA) with enhanced bioreactivity due to higher surface area and smaller crystal size. The aim of this study has been to know the nanocrystallinity effects on the response of both osteoblasts and osteoclasts (the two main cell types involved in bone remodelling) to silicon substituted hydroxyapatite. Saos-2 osteoblasts and osteoclast-like cells (differentiated from RAW-264.7 macrophages) have been cultured on the surface of nano-SiHA and SiHA disks and different cell parameters have been evaluated: cell adhesion, proliferation, viability, intracellular content of reactive oxygen species, cell cycle phases, apoptosis, cell morphology, osteoclast-like cell differentiation and resorptive activity. This comparative in vitro study evidences that nanocrystallinity of SiHA affects the cell/biomaterial interface inducing bone cell apoptosis by loss of cell anchorage (anoikis), delaying osteoclast-like cell differentiation and decreasing the resorptive activity of this cell type. These results suggest the potential use of nano-SiHA biomaterial for preventing bone resorption in treatment of osteoporotic bone. Copyright © 2016 Elsevier Inc. All rights reserved.

A comparative study of zinc, magnesium, strontium-incorporated hydroxyapatite-coated titanium implants for osseointegration of osteopenic rats

Energy Technology Data Exchange (ETDEWEB)

Tao, Zhou-Shan [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China); Zhou, Wan-Shu [Endocrine & Metabolic Diseases Unit, Affiliated Hospital of Guizhou Medical University, Guizhou 550001 (China); He, Xing-Wen [Department of Orthopaedic Surgery, Hangzhou Bay Hospital of Ningbo, 315000 (China); Liu, Wei [Department of Orthopaedic Surgery, Jingmen No. 1 People' s Hospital, Jingmen 44800, Hubei (China); Bai, Bing-Li; Zhou, Qiang; Huang, Zheng-Liang; Tu, Kai-kai; Li, Hang; Sun, Tao [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China); Lv, Yang-Xun [Department of Orthopaedic Surgery, Wenzhou Central Hospital, Wenzhou, Zhejiang 325000 (China); Cui, Wei [Sichuan Provincial Orthopedics Hospital, No. 132 West First Section First Ring Road, Chengdu, Sichuan 610000 (China); Yang, Lei, E-mail: tzs19900327@163.com [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China)

2016-05-01

Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), magnesium (Mg), and strontium (Sr) present a beneficial effect on bone growth, and positively affect bone regeneration. The aim of this study was to confirm the different effects of the fixation strength of Zn, Mg, Sr-substituted hydroxyapatite-coated (Zn-HA-coated, Mg-HA-coated, Sr-HA-coated) titanium implants via electrochemical deposition in the osteoporotic condition. Female Sprague–Dawley rats were used for this study. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group HA; group Zn-HA; group Mg-HA and group Sr-HA. Afterwards, all rats from groups HA, Zn-HA, Mg-HA and Sr-HA received implants with hydroxyapatite containing 0%, 10% Zn ions, 10% Mg ions, and 10% Sr ions. Implants were inserted bilaterally in all animals until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. All treatment groups increased new bone formation around the surface of titanium rods and push-out force; group Sr-HA showed the strongest effects on new bone formation and biomechanical strength. Additionally, there are significant differences in bone formation and push-out force was observed between groups Zn-HA and Mg-HA. This finding suggests that Zn, Mg, Sr-substituted hydroxyapatite coatings can improve implant osseointegration, and the 10% Sr coating exhibited the best properties for implant osseointegration among the tested coatings in osteoporosis rats. - Highlights: • Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. • However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), Magnesium(Mg), Strontium (Sr) present a benificial effect on bone

Improvement of the stability of hydroxyapatite through glass ceramic reinforcement.

Science.gov (United States)

Ha, Na Ra; Yang, Zheng Xun; Hwang, Kyu Hong; Kim, Tae Suk; Lee, Jong Kook

2010-05-01

Hydroxyapatite has achieved significant application in orthopedic and dental implants due to its excellent biocompatibility. Sintered hydroxyapatites showed significant dissolution, however, after their immersion in water or simulated body fluid (SBF). This grain boundary dissolution, even in pure hydroxyapatites, resulted in grain separation at the surfaces, and finally, in fracture. In this study, hydroxyapatite ceramics containing apatite-wollastonite (AW) or calcium silicate (SG) glass ceramics as additives were prepared to prevent the dissolution. AW and SG glass ceramics were added at 0-7 wt% and powder-compacted uniaxially followed by firing at moisture conditions. The glass phase was incorporated into the hydroxyapatite to act as a sintering aid, followed by crystallization, to improve the mechanical properties without reducing the biocompatibility. As seen in the results of the dissolution test, a significant amount of damage was reduced even after more than 14 days. TEM and SEM showed no decomposition of HA to the secondary phase, and the fracture toughness increased, becoming even higher than that of the commercial hydroxyapatite.

Fibrous hydroxyapatite-carbon nanotube composites by chemical vapor deposition : In situ fabrication, structural and morphological characterization

NARCIS (Netherlands)

Kosma, Vassiliki; Tsoufis, Theodoros; Koliou, Theodora; Kazantzis, Antonios; Beltsios, Konstantinos; De Hosson, Jeff Th. M.; Gournis, Dimitrios

2013-01-01

Fibrous hydroxyapatite (HA)-carbon nanotube composites were synthesized by the catalytic decomposition of acetylene over Fe-Co bimetallic catalysts supported on the fibrous HA. Two forms of fibrous HA (distinct needle-like monocrystals and spherulitic aggregates of needles) were synthesized using a

Thermal Diffusivity in Bone and Hydroxyapatite

Science.gov (United States)

Calderón, A.; Peña Rodríguez, G.; Muñoz Hernández, R. A.; Díaz Gongora, J. A. I.; Mejia Barradas, C. M.

2004-09-01

We report thermal diffusivity measurements in bull bone and commercial hydroxyapatite (HA), both in powder form, in order to determinate the thermal compatibility between these materials. Besides this, we report a comparison between these measured values and those of metallic samples frequently used in implants, as high purity titanium and stainless steel. Our results show a good thermal compatibility (74%) between HA and bone, both in powder form. Finally, it was obtained a one order of magnitude difference between the thermal diffusivity values of metallic samples and those corresponding values to bone and HA being this difference greater in titanium than in stainless steel, which is important to consider in some biomedical and dental applications.

Limitation of biocompatibility of hydrated nanocrystalline hydroxyapatite

Science.gov (United States)

Minaychev, V. V.; Teleshev, A. T.; Gorshenev, V. N.; Yakovleva, M. A.; Fomichev, V. A.; Pankratov, A. S.; Menshikh, K. A.; Fadeev, R. S.; Fadeeva, I. S.; Senotov, A. S.; Kobyakova, M. I.; Yurasova, Yu B.; Akatov, V. S.

2018-04-01

Nanostructured hydroxyapatite (HA) in the form of hydrated paste is considered to be a promising material for a minor-invasive surgical curing of bone tissue injure. However questions about adhesion of cells on this material and its biocompatibility still remain. In this study biocompatibility of paste-formed nanosized HA (nano-HA) by in vitro methods is investigated. Nano-HA (particles sized about 20 nm) was synthesized under conditions of mechano-acoustic activation of an aqueous reaction mixture of ammonium hydrophosphate and calcium nitrate. It was ascertained that nanocrystalline paste was not cytotoxic although limitation of adhesion, spreading and growth of the cells on its surface was revealed. The results obtained point on the need of modification of hydrated nano-HA in the aims of increasing its biocompatibility and osteoplastic potential.

Nanostructured hydroxyapatite powders produced by a flame-based technique

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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.

Electrophoretic Deposition of Hydroxyapatite Film Containing Re-Doped MoS2 Nanoparticles

Directory of Open Access Journals (Sweden)

Hila Shalom

2018-02-01

Full Text Available Films combining hydroxyapatite (HA with minute amounts (ca. 1 weight % of (rhenium doped fullerene-like MoS2 (IF nanoparticles were deposited onto porous titanium substrate through electrophoretic process (EPD. The films were analyzed by scanning electron microscopy (SEM, X-ray diffraction and Raman spectroscopy. The SEM analysis showed relatively uniform coatings of the HA + IF on the titanium substrate. Chemical composition analysis using energy dispersive X-ray spectroscopy (EDS of the coatings revealed the presence of calcium phosphate minerals like hydroxyapatite, as a majority phase. Tribological tests were undertaken showing that the IF nanoparticles endow the HA film very low friction and wear characteristics. Such films could be of interest for various medical technologies. Means for improving the adhesion of the film to the underlying substrate and its fracture toughness, without compromising its biocompatibility are discussed at the end.

Evaluation of a setting reaction pathway in the novel composite TiHA-CSD bone cement by FT-Raman and FT-IR spectroscopy

Science.gov (United States)

Paluszkiewicz, Czesława; Czechowska, Joanna; Ślósarczyk, Anna; Paszkiewicz, Zofia

2013-02-01

The aim of this study was to determine a setting reaction pathway in a novel, surgically handy implant material, based on calcium sulfate hemihydrate (CSH) and titanium doped hydroxyapatite (TiHA). The previous studies confirmed superior biological properties of TiHA in comparison to the undoped hydroxyapatite (HA) what makes it highly attractive for future medical applications. In this study the three types of titanium modified HA powders: untreated, calcined at 800 °C, sintered at 1250 °C and CSH were used to produce bone cements. The Fourier Transform-InfraRed (FT-IR) spectroscopy and Raman spectroscopy were applied to evaluate processes taking place during the setting of the studied materials. Our results undoubtedly confirmed that the reaction pathways and the phase compositions differed significantly for set cements and were dependent on the initial heat treatment of TiHA powder. Final materials were multiphase composites consisting of calcium sulfate dihydrate, bassanite, tricalcium phosphate, hydroxyapatite and calcium titanate (perovskite). The FT-IR and Scanning Electron Microscopy (SEM) measurements performed after the incubation of the cement samples in the simulated body fluid (SBF), indicate on high bioactive potential of the obtained bone cements.

Biomimetic Growth of Hydroxyapatite on Kenaf Fibers

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Saiful Izwan Abd Razak

2016-01-01

Full Text Available Biomimetic hydroxyapatite (HA growth on mercerized kenaf fiber (KF was achieved by immersion in a simulated body fluid (SBF solution with the addition of a chelating agent. An electron micrograph revealed uniform HA layers on the KF within 14 days of immersion with significant vibrational peaks of HA components. The tensile tests showed no significant drops in the unit break of the modified fibers. This new bone-like apatite coating on KF can be useful in the field of bone tissue engineering. The key motivation for this new approach was that it utilizes the abundantly available kenaf plant resource as the biobased template.

Flexible (Polyactive®) versus rigid (hydroxyapatite) dental implants

NARCIS (Netherlands)

Meijer, G.J.; Heethaar, J.; Cune, M.S.; de Putter, C.; van Blitterswijk, Clemens

1997-01-01

In a beagle dog study, the peri-implant bone changes around flexible (Polyactive®) and rigid hydroxyapatite (HA) implants were investigated radiographically by quantitative digital subtraction analysis and by assessment of marginal bone height, with the aid of a computerized method. A loss of

Physical-mechanical characterization of hydroxyapatite-titanium oxide composites made by the polymeric sponge method

International Nuclear Information System (INIS)

Galdino, A.G.S.; Zavaglia, C.A.C.

2011-01-01

Bioceramics have been used as bone reconstruction materials since last decades, where hydroxyapatite is one of the most used for this purpose. However, hydroxyapatite's mechanical strength is not so high when compared to other bioceramics. This work aimed on characterizing physically and mechanically composites of HA-TiO_2. Samples were made by the polymeric sponge method with 70% - 30% wt., 60% - 40% wt. and 50% - 50% wt. of HA - TiO_2, calcined at 550 deg C for sponge burning and sintered at 1250 deg C, 1300 deg C and 1350 deg C. Samples were submitted to mechanical essays of compression and Hardness Vickers and to physical essays of water absorption, apparent density, burning linear retraction and apparent density. Results showed relatively better than those of pure hydroxyapatite and they are in accordance with the literature. (author)

Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming.

Science.gov (United States)

Vaezi, Mohammad; Black, Cameron; Gibbs, David M R; Oreffo, Richard O C; Brady, Mark; Moshrefi-Torbati, Mohamed; Yang, Shoufeng

2016-05-26

Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK) has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA) composite with a unique configuration in which the bioactive phase (i.e., HA) distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility.

Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming

Directory of Open Access Journals (Sweden)

Mohammad Vaezi

2016-05-01

Full Text Available Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA composite with a unique configuration in which the bioactive phase (i.e., HA distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility.

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method. Optimisation, characterisation and rheology.

Science.gov (United States)

Tredwin, Christopher J; Young, Anne M; Georgiou, George; Shin, Song-Hee; Kim, Hae-Won; Knowles, Jonathan C

2013-02-01

Currently, most titanium implant coatings are made using hydroxyapatite and a plasma spraying technique. There are however limitations associated with plasma spraying processes including poor adherence, high porosity and cost. An alternative method utilising the sol-gel technique offers many potential advantages but is currently lacking research data for this application. It was the objective of this study to characterise and optimise the production of Hydroxyapatite (HA), fluorhydroxyapatite (FHA) and fluorapatite (FA) using a sol-gel technique and assess the rheological properties of these materials. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethylphosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the sol-gel derived FHA and FA. Optimisation of the chemistry and subsequent characterisation of the sol-gel derived materials was carried out using X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). Rheology of the sol-gels was investigated using a viscometer and contact angle measurement. A protocol was established that allowed synthesis of HA, FHA and FA that were at least 99% phase pure. The more fluoride incorporated into the apatite structure; the lower the crystallisation temperature, the smaller the unit cell size (changes in the a-axis), the higher the viscosity and contact angle of the sol-gel derived apatite. A technique has been developed for the production of HA, FHA and FA by the sol-gel technique. Increasing fluoride substitution in the apatite structure alters the potential coating properties. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Hydroxyapatite-binding peptides for bone growth and inhibition

Science.gov (United States)

Bertozzi, Carolyn R [Berkeley, CA; Song, Jie [Shrewsbury, MA; Lee, Seung-Wuk [Walnut Creek, CA

2011-09-20

Hydroxyapatite (HA)-binding peptides are selected using combinatorial phage library display. Pseudo-repetitive consensus amino acid sequences possessing periodic hydroxyl side chains in every two or three amino acid sequences are obtained. These sequences resemble the (Gly-Pro-Hyp).sub.x repeat of human type I collagen, a major component of extracellular matrices of natural bone. A consistent presence of basic amino acid residues is also observed. The peptides are synthesized by the solid-phase synthetic method and then used for template-driven HA-mineralization. Microscopy reveal that the peptides template the growth of polycrystalline HA crystals .about.40 nm in size.

Cell shape and spreading of stromal (mesenchymal) stem cells cultured on fibronectin coated gold and hydroxyapatite surfaces

DEFF Research Database (Denmark)

Dolatshahi-Pirouz, A; Jensen, Thomas Hartvig Lindkjær; Kolind, Kristian

2011-01-01

In order to identify the cellular mechanisms leading to the biocompatibility of hydroxyapatite implants, we studied the interaction of human bone marrow derived stromal (mesenchymal) stem cells (hMSCs) with fibronectin-coated gold (Au) and hydroxyapatite (HA) surfaces. The adsorption of fibronectin...

Mechanisms of uranium interactions with hydroxyapatite: Implications for groundwater remediation

Science.gov (United States)

Fuller, C.C.; Bargar, J.R.; Davis, J.A.; Piana, M.J.

2002-01-01

The speciation of U(VI) sorbed to synthetic hydroxyapatite was investigated using a combination of U LIII-edge XAS, synchrotron XRD, batch uptake measurements, and SEM-EDS. The mechanisms of U(VI) removal by apatite were determined in order to evaluate the feasibility of apatitebased in-situ permeable reactive barriers (PRBs). In batch U(VI) uptake experiments with synthetic hydroxyapatite (HA), near complete removal of dissolved uranium (>99.5%) to use in development of PRBs for groundwater U(VI) remediation.

Synthesis of hydroxyapatite/multi-walled carbon nanotubes for the removal of fluoride ions from solution

International Nuclear Information System (INIS)

Ruan, Zhongyuan; Tian, Yaxi; Ruan, Jifu; Cui, Guijia; Iqbal, Kanwal; Iqbal, Anam; Ye, Herui; Yang, Zhangzhong; Yan, Shiqiang

2017-01-01

Graphical abstract: Hydroxyapatite nucleated and grown on Multi-walled carbon nanotubes (HA-MWCNTs) showed enhanced fluoride removal performance. - Highlights: • Noval HA nanoparticles and HA-MWCNTs composites were successfully synthesized for the first time. • The synthesized HA-MWCNTs composites exhibited a higher defluoridation capacity of 39.22 mg g"−"1. • It could reduced the fluoride concentration of the real waste water from 8.79 mg L"−"1 to approximately 0.25 mg L"−"1. - Abstract: A novel composite material, hydroxyapatite (HA)-multi-walled carbon nanotubes (MWCNTs), was prepared using a simple in-situ sol-gel method, and was used for the first time to remove fluoride from water. The novel HA-MWCNTs were characterized using TEM, FT-IR, BET and XRD analysis. The TEM and SAED results revealed that the MWCNTs were uniformly encapsulated by hydroxyapatite nanoparticles. The synthesized HA-MWCNTs had a high specific surface area (180.504 m"2 g"−"1), with an average pore width (14.607 nm) and pore volume (0.774 cm"3 g"−"1), which produced a defluoridation capacity (DC) of 30.22 mgF"− g"−"1. This value was greater than unmodified hydroxyapatite (HA), which exhibited a larger specific surface area (172.233 m"2 g"−"1) and an excellent DC of 17.80 mgF"− g"−"1. A number of pertinent parameters that could affect the defluoridation performance of the HA/MWCNTs including weight ratios of the two key materials, solution pH and competing anions were carefully and comprehensively examined. It was found that the adsorption results followed the Langmuir and Freundlich isotherm model, and the sorption kinetics of the F"− appeared to exhibit a pseudo second order. Moreover, the adsorption reaction was spontaneous and endothermic and appeared to exhibit a higher initial adsorption rate. This reaction appeared to occur result from both anion exchange and electrostatic interactions. When the HA-MWCNTs (MH6) were at an adsorbent dose of 2.0 g L"−"1

Bone Regeneration of Hydroxyapatite with Granular Form or Porous Scaffold in Canine Alveolar Sockets

Science.gov (United States)

JANG, SEOK JIN; KIM, SE EUN; HAN, TAE SUNG; SON, JUN SIK; KANG, SEONG SOO; CHOI, SEOK HWA

2017-01-01

This study was undertaken to assess bone regeneration using hydroxyapatite (HA). The primary focus was comparison of bone regeneration between granular HA (gHA) forms and porous HA (pHA) scaffold. The extracted canine alveolar sockets were divided with three groups: control, gHA and pHA. Osteogenic effect in the gHA and pHA groups showed bone-specific surface and bone mineral density to be significantly higher than that of the control group (psocket healing. For new bone formation during 8 weeks' post-implantation, HA with porous scaffold was superior to the granular form of HA. PMID:28438860

Suspension thermal spraying of hydroxyapatite: microstructure and in vitro behaviour.

Science.gov (United States)

Bolelli, Giovanni; Bellucci, Devis; Cannillo, Valeria; Lusvarghi, Luca; Sola, Antonella; Stiegler, Nico; Müller, Philipp; Killinger, Andreas; Gadow, Rainer; Altomare, Lina; De Nardo, Luigi

2014-01-01

In cementless fixation of metallic prostheses, bony ingrowth onto the implant surface is often promoted by osteoconductive plasma-sprayed hydroxyapatite coatings. The present work explores the use of the innovative High Velocity Suspension Flame Spraying (HVSFS) process to coat Ti substrates with thin homogeneous hydroxyapatite coatings. The HVSFS hydroxyapatite coatings studied were dense, 27-37μm thick, with some transverse microcracks. Lamellae were sintered together and nearly unidentifiable, unlike conventional plasma-sprayed hydroxyapatite. Crystallinities of 10%-70% were obtained, depending on the deposition parameters and the use of a TiO2 bond coat. The average hardness of layers with low (hydroxyapatite, with a Weibull modulus of ≈3.3. During soaking in simulated body fluid, glassy coatings were progressively resorbed and replaced by a new, precipitated hydroxyapatite layer, whereas coatings with 70% crystallinity were stable up to 14days of immersion. The interpretation of the precipitation behaviour was also assisted by surface charge assessments, performed through Z-potential measurements. During in vitro tests, HA coatings showed no cytotoxicity towards the SAOS-2 osteoblast cell line, and surface cell proliferation was comparable with proliferation on reference polystyrene culture plates. © 2013.

Osteogenesis of bone marrow mesenchymal stem cells on strontium-substituted nano-hydroxyapatite coated roughened titanium surfaces

OpenAIRE

Yang, Hua-Wei; Lin, Mao-Han; Xu, Yuan-Zhi; Shang, Guang-Wei; Wang, Rao-Rao; Chen, Kai

2015-01-01

Objective: To investigate osteogenesis of bone marrow mesenchymal stem cells (BMSCs) on strontium-substituted nano-hydroxyapatite (Sr-HA) coated roughened titanium surfaces. Methods: Sr-HA coating and HA coating were fabricated on roughened titanium surfaces by electrochemical deposition technique and characterized by field emission scanning electron microscope (FESM). BMSCs were cultured on Sr-HA coating, HA coating and roughened titanium surfaces respectively. Cell proliferation, alkaline p...

Microstructure, mechanical properties, and biological response to functionally graded HA coatings

International Nuclear Information System (INIS)

Rabiei, Afsaneh; Blalock, Travis; Thomas, Brent; Cuomo, Jerry; Yang, Y.; Ong, Joo

2007-01-01

Hydroxyapatite (HA) [Ca 10 (PO 4 ) 6 (OH) 2 ] is the primary mineral content, representing 43% by weight, of bone. Applying a thin layer of HA, to the surface of a metal implant, can promote osseointegration and increase the mechanical stability of the implant. In this study, a biocompatible coating comprising an HA film with functionally graded crystallinity is being deposited on a heated substrate in an Ion Beam Assisted Deposition (IBAD) system. The microstructure of the film was studied using Transmission Electron Microscopy techniques. Finally, initial cell adhesion and cell differentiation on the coating was evaluated using ATCC CRL 1486 human embryonic palatal mesenchymal cell, an osteoblast precursor cell line. The results have shown superior mechanical properties and biological response to the functionally graded HA film

Nano-hydroxyapatite as an Efficient Polysulfide Absorbent for High-performance Li-S Batteries

International Nuclear Information System (INIS)

Liu, Naiqiang; Ai, Fei; Wang, Weikun; Shao, Hongyuan; Zhang, Hao; Wang, Anbang; Xu, Zhichuan J.; Huang, Yaqin

2016-01-01

Highlights: • Nano-HA has been demonstrated as an efficient polysulfide absorbent. • The shuttle effect of polysulfide in Li-S battery has been confined by the nano-HA. • Nano-HA used as additive improved electrochemical performance of Li-S battery. - Abstract: Lithium-sulfur (Li-S) battery is regarded as one of the most promising candidates for developing advanced energy storage system, but the polysulfide shuttle effect remains the biggest obstacle for its practical application. In this work, nano-hydroxyapatite (Ca 5 (PO 4 ) 3 (OH)) was used as an additive in the sulfur cathode and carbon-coated separator to prevent the polysulfide shuttle effect and thus to achieve the high performance. The sulfur cathode with nano-hydroxyapatite exhibited a higher reversible capacity and a more stable cycling performance than that of the pristine sulfur cathode. The improved capacity retention from 58% (100th) to 73% (200th) after introducing nano-hydroxyapatite into the sulfur cathode confirmed its strong polysulfide absorption ability. Furthermore, a nano-hydroxyapatite modified separator was developed to suppress the polysulfide shuttle effect and to facilitate the reutilization of sulfur species. The nano-hydroxyapatite particles served as polysulfide absorbents to bind polysulfides and suppress their diffusion to the anode. The batteries assembled with this separator exhibited a high reversible capacity of 886 mAhg −1 at 0.1C and 718 mAh g −1 at 0.5C after 200 cycles, with a low capacity fading of ∼0.10-0.11% per-cycle. At the highest sulfur loading of 4.5 mg cm −2 used for practical applications, the reversible areal capacity was much higher than the areal capacity (4 mAh cm −2 ) of commercial lithium-ion batteries. Therefore, the strategy using nano-hydroxyapatite as polysulfide absorbent shows great potential for solving the polysulfide shuttle problem and developing high performance Li-S batteries.

Mechanical failure of hydroxyapatite-coated titanium and cobalt-chromium-molybdenum alloy implants. An animal study

DEFF Research Database (Denmark)

Nimb, L; Gotfredsen, K; Steen Jensen, J

1993-01-01

Defects in the hydroxyapatite (HA) ceramic coatings applied to metallic implant systems may occur at the time of insertion or at the time of in vivo loading. However, defects may also occur with time because of interaction with physiological fluids. A canine study was performed to make a histolog......Defects in the hydroxyapatite (HA) ceramic coatings applied to metallic implant systems may occur at the time of insertion or at the time of in vivo loading. However, defects may also occur with time because of interaction with physiological fluids. A canine study was performed to make...

Nanoporous hydroxyapatite/sodium titanate bilayer on titanium implants for improved osteointegration.

Science.gov (United States)

Carradò, A; Perrin-Schmitt, F; Le, Q V; Giraudel, M; Fischer, C; Koenig, G; Jacomine, L; Behr, L; Chalom, A; Fiette, L; Morlet, A; Pourroy, G

2017-03-01

The aim of this study was to improve the strength and quality of the titanium-hydroxyapatite interface in order to prevent long-term failure of the implanted devices originating from coating delamination and to test it in an in-vivo model. Ti disks and dental commercial implants were etched in Kroll solution. Thermochemical treatments of the acid-etched titanium were combined with sol-gel hydroxyapatite (HA) coating processes to obtain a nanoporous hydroxyapatite/sodium titanate bilayer. The sodium titanate layer was created by incorporating sodium ions onto the Ti surface during a NaOH alkaline treatment and stabilized using a heat treatment. HA layer was added by dip-coating in a sol-gel solution. The bioactivity was assessed in vitro with murine MC3T3-E1 and human SaOs-2 cells. Functional and histopathological evaluations of the coated Ti implants were performed at 22, 34 and 60days of implantation in a dog lower mandible model. Nanoporous hydroxyapatite/sodium titanate bilayer on titanium implants was sensitive neither to crack propagation nor to layer delamination. The in vitro results on murine MC3T3-E1 and human SaOs-2 cells confirm the advantage of this coating regarding the capacity of cell growth and differentiation. Signs of progressive bone incorporation, such as cancellous bone formed in contact with the implant over the existing compact bone, were notable as early as day 22. Overall, osteoconduction and osteointegration mean scores were higher for test implants compared to the controls at 22 and 34 days. Nanoporous hydroxyapatite/sodium titanate bilayer improves the in-vivo osteoconduction and osteointegration. It prevents the delamination during the screwing and it could increase HA-coated dental implant stability without adhesive failures. The combination of thermochemical treatments with dip coating is a low-cost strategy. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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

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.

Continuous microwave flow synthesis of mesoporous hydroxyapatite

International Nuclear Information System (INIS)

Akram, Muhammad; Alshemary, Ammar Z.; Goh, Yi-Fan; Wan Ibrahim, Wan Aini; Lintang, Hendrik O.; Hussain, Rafaqat

2015-01-01

We have successfully used continuous microwave flow synthesis (CMFS) technique for the template free synthesis of mesoporous hydroxyapatite. The continuous microwave flow reactor consisted of a modified 2.45 GHz household microwave, peristaltic pumps and a Teflon coil. This cost effective and efficient system was exploited to produce semi-crystalline phase pure nano-sized hydroxyapatite. Effect of microwave power, retention time and the concentration of reactants on the phase purity, degree of crystallinity and surface area of the final product was studied in detail. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to study the phase purity and composition of the product, while transmission electron microscopy (TEM) was used to study the effect of process parameters on the morphology of hydroxyapatite. The TEM analysis confirmed the formation of spherical particles at low microwave power; however the morphology of the particles changed to mesoporous needle and rod-like structure upon exposing the reaction mixture to higher microwave power and longer retention time inside the microwave. The in-vitro ion dissolution behavior of the as synthesized hydroxyapatite was studied by determining the amount of Ca 2+ ion released in SBF solution. - Highlights: • Continuous microwave flow synthesis method was used to prepare hydroxyapatite. • Increase in microwave power enhanced the degree of crystallinity. • TEM images confirmed the presence of mesopores on the surface of HA

Continuous microwave flow synthesis of mesoporous hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

Akram, Muhammad; Alshemary, Ammar Z.; Goh, Yi-Fan; Wan Ibrahim, Wan Aini [Department of Chemistry, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Lintang, Hendrik O. [Centre for Sustainable Nanomaterials (CSNano), Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (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 Johor Bahru, Johor (Malaysia)

2015-11-01

We have successfully used continuous microwave flow synthesis (CMFS) technique for the template free synthesis of mesoporous hydroxyapatite. The continuous microwave flow reactor consisted of a modified 2.45 GHz household microwave, peristaltic pumps and a Teflon coil. This cost effective and efficient system was exploited to produce semi-crystalline phase pure nano-sized hydroxyapatite. Effect of microwave power, retention time and the concentration of reactants on the phase purity, degree of crystallinity and surface area of the final product was studied in detail. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to study the phase purity and composition of the product, while transmission electron microscopy (TEM) was used to study the effect of process parameters on the morphology of hydroxyapatite. The TEM analysis confirmed the formation of spherical particles at low microwave power; however the morphology of the particles changed to mesoporous needle and rod-like structure upon exposing the reaction mixture to higher microwave power and longer retention time inside the microwave. The in-vitro ion dissolution behavior of the as synthesized hydroxyapatite was studied by determining the amount of Ca{sup 2+} ion released in SBF solution. - Highlights: • Continuous microwave flow synthesis method was used to prepare hydroxyapatite. • Increase in microwave power enhanced the degree of crystallinity. • TEM images confirmed the presence of mesopores on the surface of HA.

Preparation and characterization of carbon nanofibrous/hydroxyapatite sheets for bone tissue engineering.

Science.gov (United States)

Abd El-Aziz, A M; El Backly, Rania M; Taha, Nahla A; El-Maghraby, Azza; Kandil, Sherif H

2017-07-01

Critical size bone defects are orthopedic defects that will not heal without intervention or that will not completely heal over the natural life time of the animal. Although bone generally has the ability to regenerate completely however, critical defects require some sort of scaffold to do so. In the current study we proposed a method to obtain a carbon nanofibrous/Hydroxyapatite (HA) bioactive scaffold. The carbon nanofibrous (CNF) nonwoven fabrics were obtained by the use of the electrospinning process of the polymeric solution of poly acrylonitrile "PAN" and subsequent stabilization and carbonization processes. The CNFs sheets were functionalized by both hydroxyapatite (HA) and bovine serum albumin (BSA). The HA was added to the electrospun solution, but in case of (BSA), it was adsorbed after the carbonization process. The changes in the properties taking place in the precursor sheets were investigated using the characterization methods (SEM, FT-IR, TGA and EDX). The prepared materials were tested for biocompatibility via subcutaneous implantation in New Zealand white rabbits. We successfully prepared biocompatible functionalized sheets, which have been modified with HA or HA and BSA. The sheets that were functionalized by both HA and BSA are more biocompatible with fewer inflammatory cells of (neutrophils and lymphocytes) than ones with only HA over the period of 3weeks. Copyright © 2017 Elsevier B.V. All rights reserved.

Mesoporous Fe3O4/hydroxyapatite composite for targeted drug delivery

International Nuclear Information System (INIS)

Gu, Lina; He, Xiaomei; Wu, Zhenyu

2014-01-01

Highlights: • Mesoporous Fe 3 O 4 /hydroxyapatite composite was synthesized by a simple, efficient and environmental friendly method. • The prepared material had a large surface area, high pore volume, and good magnetic separability. • DOX-loaded Fe 3 O 4 /hydroxyapatite composite exhibited surprising slow drug release behavior and pH-dependent behavior. - Abstract: In this contribution, we introduced a simple, efficient, and green method of preparing a mesoporous Fe 3 O 4 /hydroxyapatite (HA) composite. The as-prepared material had a large surface area, high pore volume, and good magnetic separability, which made it suitable for targeted drug delivery systems. The chemotherapeutic agent doxorubicin (DOX) was used to investigate the drug release behavior of Fe 3 O 4 /HA composite. The drug release profiles displayed a little burst effect and pH-dependent behavior. The release rate of DOX at pH 5.8 was larger than that at pH 7.4, which could be attributed to DOX protonation in acid medium. In addition, the released DOX concentrations remained at 0.83 and 1.39 μg/ml at pH 7.4 and 5.8, respectively, which indicated slow, steady, and safe release rates. Therefore, the as-prepared Fe 3 O 4 /hydroxyapatite composite could be an efficient platform for targeted anticancer drug delivery

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.

Preparation of Porous Hydroxyapatite Tablets and Porous Hydroxyapatite Coatings for Orthopaedic Use

International Nuclear Information System (INIS)

Mendez-Gonzalez, M.

2004-01-01

Porous hydroxyapatite tablets and coatings on metal substrates were obtained by the addition of polymeric additives and liofilization. Both tablets and coatings were characterized by scanning electron microscopy and x-ray diffraction. Coatings obtained by plasma spraying also exhibited interconnected porous of 100 μm while coatings obtained by laser ablation did not show any porosity. The diffraction patterns of the deposited HA were similar to that of the powder obtained by the precipitation method suggesting that no significant changes occurred during the coating procedure

Study of BSA protein adsorption/release on hydroxyapatite nanoparticles

Science.gov (United States)

Swain, Sanjaya Kumar; Sarkar, Debasish

2013-12-01

Three different spherical, rod and fibrous morphologies of hydroxyapatite (HA) nanoparticles have been prepared through control over the processing parameters like temperature, pH and Ca:P ratio. Protein adsorption/release with respect to HA nanoparticle morphologies are investigated using model protein bovine serum albumin (BSA). BSA adsorption on HA nanoparticles follows Langmuir adsorption isotherm. Thermal analysis and FT-IR spectrum confirms the BSA adhesion and retention of their secondary structure. High surface area with high Ca:P ratio nanorod adsorbs relatively more amount (28 mg BSA/gm of nanorod HA) of BSA within 48 h in comparison with counterpart fibroid and spherical morphologies. Slow and steady BSA release (75 wt% of adsorbed BSA in 96 h) from nanorod HA is found as futuristic drug delivery media.

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...

Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: Promising bone implant materials

Science.gov (United States)

Oyefusi, Adebola; Olanipekun, Opeyemi; Neelgund, Gururaj M.; Peterson, Deforest; Stone, Julia M.; Williams, Ebonee; Carson, Laura; Regisford, Gloria; Oki, Aderemi

2014-11-01

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering.

Effect of hydroxyapatite coating on risk of revision after primary total hip arthroplasty in younger patients: findings from the Danish Hip Arthroplasty Registry

DEFF Research Database (Denmark)

Paulsen, Aksel; Pedersen, Alma B; Johnsen, Søren P

2007-01-01

BACKGROUND: The effect of hydroxyapatite (HA) on implant survival in the medium and long term is uncertain. We studied the effect of HA coating of uncemented implants on the risk of cup and stem revision in primary total hip arthroplasty (THA). PATIENTS AND METHODS: Using the Danish Hip Arthropla......BACKGROUND: The effect of hydroxyapatite (HA) on implant survival in the medium and long term is uncertain. We studied the effect of HA coating of uncemented implants on the risk of cup and stem revision in primary total hip arthroplasty (THA). PATIENTS AND METHODS: Using the Danish Hip...

A simple and rapid method to graft hydroxyapatite on carbon nanotubes

International Nuclear Information System (INIS)

Neelgund, Gururaj M.; Olurode, Kehinde; Luo Zhiping; Oki, Aderemi

2011-01-01

Herein a simple and effective approach is introduced to functionalize single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA). The pristine SWCNTs were chemically activated through introduction of carboxylic groups on their surfaces by refluxing in the mixture of H 2 SO 4 and HNO 3 . The resulting carboxylated SWCNTs were further utilized for grafting of HA. The Fourier transform infrared and Raman spectroscopic studies demonstrated the formation of HA and its grafting over SWCNTs. The phase composition of HA and existence Ca 2+ and PO 4 3- ions were studied using X-ray diffraction and energy dispersive X-ray analyses, respectively. The surface morphology of functionalized SWCNTs was analyzed using scanning electron microscopy and transmission electron microscopy. Thermogravimetric analysis confirmed the existence of HA on SWCNTs by exhibiting different thermogram for pure HA and functionalized SWCNTs. Overall, this method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. - Graphical abstract: A facile approach is demonstrated for effective functionalization of single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA) to improve hydrophilicity and biocompatibility of SWCNTs. This method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. Research highlights: → This method is facile and effective to graft HA on SWCNTs. → As f-SWCNTs is a promising biomaterial to use without any further processing → This technique is economic, easy to repeat and can be optimized for mass production. → Ratio of Ca to P in f-SWCNTs was 1.65, which is near to ratio present in bone tissue.

A simple and rapid method to graft hydroxyapatite on carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Neelgund, Gururaj M.; Olurode, Kehinde [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Luo Zhiping [Microscopy and Imaging Center, Materials Science and Engineering, Texas A and M University, College Station TX 77843 (United States); Oki, Aderemi, E-mail: aroki@pvamu.edu [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States)

2011-10-10

Herein a simple and effective approach is introduced to functionalize single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA). The pristine SWCNTs were chemically activated through introduction of carboxylic groups on their surfaces by refluxing in the mixture of H{sub 2}SO{sub 4} and HNO{sub 3}. The resulting carboxylated SWCNTs were further utilized for grafting of HA. The Fourier transform infrared and Raman spectroscopic studies demonstrated the formation of HA and its grafting over SWCNTs. The phase composition of HA and existence Ca{sup 2+} and PO{sub 4}{sup 3-} ions were studied using X-ray diffraction and energy dispersive X-ray analyses, respectively. The surface morphology of functionalized SWCNTs was analyzed using scanning electron microscopy and transmission electron microscopy. Thermogravimetric analysis confirmed the existence of HA on SWCNTs by exhibiting different thermogram for pure HA and functionalized SWCNTs. Overall, this method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. - Graphical abstract: A facile approach is demonstrated for effective functionalization of single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA) to improve hydrophilicity and biocompatibility of SWCNTs. This method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. Research highlights: {yields} This method is facile and effective to graft HA on SWCNTs. {yields} As f-SWCNTs is a promising biomaterial to use without any further processing {yields} This technique is economic, easy to repeat and can be optimized for mass production. {yields} Ratio of Ca to P in f-SWCNTs was 1.65, which is near to ratio present in bone tissue.

Mechanical properties of natural chitosan/hydroxyapatite/magnetite nanocomposites for tissue engineering applications.

Science.gov (United States)

Heidari, Fatemeh; Razavi, Mehdi; E Bahrololoom, Mohammad; Bazargan-Lari, Reza; Vashaee, Daryoosh; Kotturi, Hari; Tayebi, Lobat

2016-08-01

Chitosan (CS), hydroxyapatite (HA), and magnetite (Fe3O4) have been broadly employed for bone treatment applications. Having a hybrid biomaterial composed of the aforementioned constituents not only accumulates the useful characteristics of each component, but also provides outstanding composite properties. In the present research, mechanical properties of pure CS, CS/HA, CS/HA/magnetite, and CS/magnetite were evaluated by the measurements of bending strength, elastic modulus, compressive strength and hardness values. Moreover, the morphology of the bending fracture surfaces were characterized using a scanning electron microscope (SEM) and an image analyzer. Studies were also conducted to examine the biological response of the human Mesenchymal Stem Cells (hMSCs) on different composites. We conclude that, although all of these composites possess in-vitro biocompatibility, adding hydroxyapatite and magnetite to the chitosan matrix can noticeably enhance the mechanical properties of the pure chitosan. Copyright © 2016 Elsevier B.V. All rights reserved.

Radiochemistry, pre-clinical studies and first clinical investigation of 90Y-labeled hydroxyapatite (HA) particles prepared utilizing 90Y produced by (n,γ) route

International Nuclear Information System (INIS)

Vimalnath, K.V.; Chakraborty, Sudipta; Rajeswari, A.; Sarma, H.D.; Nuwad, Jitendra; Pandey, Usha; Kamaleshwaran, K.; Shinto, Ajit; Dash, Ashutosh

2015-01-01

Introduction: The scope of using no carrier added (NCA) 90 Y [T 1/2 = 64.1 h, E β(max) = 2.28 MeV] obtained from 90 Sr/ 90 Y generator in radiation synovectomy (RSV) is widely accepted. In the present study, the prospect of using 90 Y produced by (n,γ) route in a medium flux research reactor for use in RSV was explored. Methods: Yttrium-90 was produced by thermal neutron irradiation of Y 2 O 3 target at a neutron flux of ~ 1 × 10 14 n/cm 2 .s for 14 d. The influence of various experimental parameters were systematically investigated and optimized to arrive at the most favorable conditions for the formulation of 90 Y labeled hydroxyapatite (HA) using HA particles of 1–10 μm size range. An optimized kit formulation strategy was developed for convenient one-step compounding of 90 Y-HA, which is easily adaptable at hospital radiopharmacy. The pre-clinical biological evaluation of 90 Y-HA particles was studied by carrying out biodistribution and bioluminiscence imaging studies in Wistar rats. The first clinical investigation using the radiolabeled preparation was performed on a patient suffering from chronic arthritis in knee joint by administering 185 MBq 90 Y-HA formulated at the hospital radiopharmacy deploying the proposed strategy. Results: Yttrium-90 was produced with a specific activity of 851 ± 111 MBq/mg and radionuclidic purity of 99.95 ± 0.02%. 90 Y-labeled HA particles (185 ± 10 MBq doses) were formulated in high radiochemical purity (> 99%) and excellent in vitro stability. The preparation showed promising results in pre-clinical studies carried out in Wistar rats. The preliminary results of the first clinical investigation of 90 Y-HA preparation in a patient with rheumatoid arthritis in knee joints demonstrated the effectiveness of the formulation prepared using 90 Y produced via (n,γ) route in the management of the disease. Conclusion: The studies revealed that effective utilization of 90 Y produced via (n,γ) route in a medium flux research

166Ho-HA evaluation as therapeutic agent for rheumatoid arthritis treatment

International Nuclear Information System (INIS)

Chandia, M.C.; Errazu, X.C.; Pinto, L.N.; Godoy, N.O.; Avila, M.J.; Mendoza, P.; Mendoza, J.; Jofre, J.; Sirraalta, P.

2002-01-01

Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This leads to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate 166 Ho-Hydroxyapatite ( 166 Ho-HA) as potential radiopharmaceutical for the symptomatic treatment of chronic and acute arthritis. Materials and Methods: Holmiun-166 was produced by irradiation of Ho 2 O 3 at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthesized. Its labelling and quality controls follows the internationally accepted procedures. An antigen's arthritis was induced to eight New Zealand rabbits with the 166 Ho-HA radiochemical being administered thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon clinical improvement and images from the inflamated articulation using 67 Ga citrate before and after 166 Ho-HA injection. Results: The radiochemical purity of the inoculated compound was greater than 98% as measured under sterility conditions. Clinically, an inflammation reduction (2 cm), appetite improvement and general well being was observed. The 166 Ho-HA distribution and localization was monitored using gamma camera images taken at 4 and 24 h. There was no evidence of extra articular leakage. From the 67 Ga citrate imaging, the acute group shows an overall improvement of well being corresponding to a lesser uptake at the inflamated articulation, regarding to the chronic group. The 166 Ho-HA double doses, compared to the single doses, suggest a reduced uptake of 67 Ga citrate at the inflamated tissue, meaning an increased therapeutic effect. Conclusions: 166 Ho-HA is useful as therapeutic agent for the symptomatic treatment of rheumatoid arthritis as shown by imaging and clinical examination

166 Ho-HA Evaluation as therapeutic agent for rheumatoid arthritis treatment

International Nuclear Information System (INIS)

Chandia, M; Errazu, X; Mendoza, P; Troncoso, F; Jofre, J; Sierralta, P

2003-01-01

Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This lead to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate 166 Ho-Hydroxyapatite ( 166 Ho-HA) as potential radiopharmaceutical for the syntomatic treatment of chronic and acute arthritis Materials and Methods: 166 Holmiun was produced by irradiation of Ho 2 O 3 at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthetized. Its labelling and quality controls follows the internationally accepted procedures. An antigen arthritis was induced to eight New Zealand rabbits with the 166 Ho-HA radiochemical being administred thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon clinical improvement and images from the inflamated articulation using 67 Ga citrate before and after 166 Ho-HA injection. Results: The radiochemical purity of the innoculated compound was greater than 98% as measured under sterility conditions. Clinically, an inflamation reduction (2 cm), appetite improvement and general well being was observed. The 166 Ho-HA distribution and localization was monitored using gamma camera images taken at 4 and 24 h. There was no evidence of extraarticular leakage. From the 67 Ga citrate imaging, the acute group shows an overall improvement of well being corresponding to a lesser uptake at the inflamated articulation, regarding to the chronic group. The 166 Ho-HA double dosis, compared to the single dosis, suggest a reduced uptake of 67 Ga citrate at the inflamated tissue, meaning an increased therapeutic effect. Conclusions: 166 Ho-HA is usefull as therapeutic agent for the syntomatic treatment of rheumatoideal arthritis as shown by imaging and clinical examination (author)

Characterization and Mineralization of Strontium Doped Nano Hydroxyapatite Coating on Titanium Rods

Directory of Open Access Journals (Sweden)

Chuang WANG

2017-08-01

Full Text Available Pure nano hydroxyapatite (nHA and strontium doped nano hydroxyapatite (Sr-nHA, Sr/(Ca+Sr =10% were prepared by a one-step method which mainly used the principle of homogeneous phase co-precipitation. Fourier transform infrared spectroscopy (FT-IR revealed that the intensity of absorption was decreased with Sr doping. X-ray diffraction (XRD showed that special peak position of Sr-nHA shifted to a smaller 2θ angle compared with the pure nHA. Both the pure nHA (39.46±11.19nm in length and 15.90±3.65 nm in width and Sr-nHA (32.95±10.21 nm in length and 13.18±3.18 nm in width samples showed a tiny nano-rod feature. Moreover, Tc4 (Ti-6Al-4V rods (1 mm in diameter and 20 mm in length coated with pure nHA or Sr-nHA were prepared by high-energy plasma spraying. Elements of calcium (Ca, phosphorus (P, oxygen (O and Sr were detected on the Sr-nHA coating surface by Energy Dispersive Spectrometry (EDS. XRD result also indicates the chemical composition almost did not change significantly after spraying. By immersion in the simulated body fluid (SBF, in vitro mineralization ability was estimated and the superficial coats were evaluated by scanning electron microscopy (SEM and XRD. The results showed that Sr-nHA spraying surface has a better mineralization ability than the pure nHA coating. Therefore, the synthesized Sr-nHA would have potential for biological prostheses and other implantable materials.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.17254

Synthesis and characterization of strontium-substituted hydroxyapatite nanoparticles for bone regeneration

Energy Technology Data Exchange (ETDEWEB)

Frasnelli, Matteo, E-mail: matteo.frasnelli@unitn.it [Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento (Italy); INSTM Research Unit, Via G. Giusti 9, 50123 Firenze (Italy); Cristofaro, Francesco [Department of Molecular Medicine, Center for Health Technologies (CHT), University of Pavia, Viale Taramelli 3/b, 27100 Pavia (Italy); Sglavo, Vincenzo M. [Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento (Italy); INSTM Research Unit, Via G. Giusti 9, 50123 Firenze (Italy); Dirè, Sandra; Callone, Emanuela [Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento (Italy); “Klaus Müller” NMR Laboratory, Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento (Italy); Ceccato, Riccardo [Department of Industrial Engineering, University of Trento, Via Sommarive 9, 38123 Trento (Italy); Bruni, Giovanna [Department of Chemistry, Physical-Chemistry Section, University of Pavia, Viale Taramelli 16, 27100 Pavia (PV) (Italy); Cornaglia, Antonia Icaro [Department of Experimental Medicine, Faculty of Medicine, University of Pavia (Italy); Visai, Livia [Department of Molecular Medicine, Center for Health Technologies (CHT), University of Pavia, Viale Taramelli 3/b, 27100 Pavia (Italy); Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Via S. Boezio, 28, 27100 Pavia (PV) (Italy)

2017-02-01

The production of stable suspensions of strontium-substituted hydroxyapatite (Sr-HA) nanopowders, as Sr ions vector for bone tissue regeneration, was carried out in the present work. Sr-HA nanopowders were synthesized via aqueous precipitation methods using Sr{sup 2+} amount from 0 to 100 mol% and were characterized by several complementary techniques such as solid-state Nuclear Magnetic Resonance spectroscopy, X-ray diffraction, Infrared spectroscopy, N{sub 2} physisorption and Transmission Electron Microscopy. The substitution of Ca{sup 2+} with Sr{sup 2+} in HA is always isomorphic with gradual evolution between the two limit compositions (containing 100% Ca and 100% Sr), this pointing out the homogeneity of the synthesized nanopowders and the complete solubility of strontium in HA lattice. Strontium addition is responsible for an increasing c/a ratio in the triclinic unit cell. A significant variation of the nanopowders shape and dimension is also observed, a preferential growth along the c-axis direction being evident at higher strontium loads. Modifications in the local chemical environment of phosphate and hydroxyl groups in the apatite lattice are also observed. Stable suspensions were produced by dispersing the synthesized nanopowders in bovine serum albumin. Characterization by Dynamic Light Scattering and ζ-potential determination allowed to show that Ca{sup 2+} → Sr{sup 2+} substitution influences the hydrodynamic diameter, which is always twice the particles size determined by TEM, the nanoparticles being always negatively charged as a result from the albumin rearrangement upon the interaction with nanoparticles surface. The biocompatibility of the suspensions was studied in terms of cell viability, apoptosis, proliferation and morphology, using osteosarcoma cell line SAOS-2. The data pointed out an increased cell proliferation for HA nanoparticles containing larger Sr{sup 2+} load, the cells morphology remaining essentially unaffected. - Highlights

The synthesis of hydroxyapatite through the precipitation method.

Science.gov (United States)

Shah, Rizal K; Fahmi, M N; Mat, Akil H; Zainal, Arifin A

2004-05-01

Hydroxyapatite (HA) has been earmarked as suitable for implantation within the human of its chemical makeup to human bone. In this paper, HA powders were synthesized via the precipitation method where phosphoric acid (H3PO4) was titrated into calcium hydroxide solution [Ca(OH)2]. Two parameters such as temperature and stirring rate were identified as factors that influenced the amount and purity of HA powder. Phase identification of the synthesized powder was done using X-Ray Diffraction (XRD). The results show that HA phase can be synthesized from this titration process of Ca(OH)2 and H3PO4 with yield amount of HA powder around 45 - 61 grams but with less than hundred percent purity. In order to study the effect of heat treatment to HA crystals structure, HA powder was calcined at 850 degrees C for 2 hours. It's found that the degree of crystallinity increases after calcination because of lattice expansion when the materials were heated at higher temperature

In vitro hydroxyapatite adsorbed salivary proteins

International Nuclear Information System (INIS)

Vitorino, Rui; Lobo, Maria Joao C.; Duarte, Jose; Ferrer-Correia, Antonio J.; Tomer, Kenneth B.; Dubin, Joshua R.; Domingues, Pedro M.; Amado, Francisco M.L.

2004-01-01

In spite of the present knowledge about saliva components and their respective functions, the mechanism(s) of pellicle and dental plaque formation have hitherto remained obscure. This has prompted recent efforts on in vitro studies using hydroxyapatite (HA) as an enamel model. In the present study salivary proteins adsorbed to HA were extracted with TFA and EDTA and resolved by 2D electrophoresis over a pH range between 3 and 10, digested, and then analysed by MALDI-TOF/TOF mass spectrometry and tandem mass spectrometry. Nineteen different proteins were identified using automated MS and MS/MS data acquisition. Among them, cystatins, amylase, carbonic anhydrase, and calgranulin B, were identified

Mechanical, thermal, rheological and morphological behaviour of irradiated PP/HA composites

International Nuclear Information System (INIS)

Ramirez, C.; Albano, C.; Karam, A.; Dominguez, N.; Sanchez, Y.; Gonzalez, G.

2005-01-01

Hydroxyapatite (HA) reinforced polypropylene (PP) composites are being developed as bone graft materials. In this research, the effect of γ irradiation on mechanical, rheological, thermal and morphological behaviour of PP-HA composites was studied. The melt flow index of polymer increased markedly when it was exposed to radiation. This is indicative of chain scission reaction as the predominant process. During the tensile testing, the composites exhibited brittle behaviour, showing no fluency point. Elongation at break showed a tendency to decrease with the increase in radiation dose while stress at break did not show significant variation with radiation dose. High HA content (>20%) and radiation dose (25 kGy) had significant influence on thermal stability

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.

Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations

International Nuclear Information System (INIS)

Cisneros-Pineda, Olga G.; Herrera Kao, Wilberth; Loría-Bastarrachea, María I.; Veranes-Pantoja, Yaymarilis; Cauich-Rodríguez, Juan V.; Cervantes-Uc, José M.

2014-01-01

The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone–water than that obtained for methanol–water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol–water system containing MPS at 3 wt.% provides the better results during silanization process of HA. - Highlights: • Effect of MPS concentration and solvents during HA silanization was studied. • Silanization rendered HA has lower crystallinity compared to untreated HA. • Silicon concentration was higher for acetone than that obtained using methanol. • Methanol–water system containing MPS at 3 wt.% provides the better results

Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations

Energy Technology Data Exchange (ETDEWEB)

Cisneros-Pineda, Olga G.; Herrera Kao, Wilberth; Loría-Bastarrachea, María I. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Veranes-Pantoja, Yaymarilis [Centro de Biomateriales, Universidad de la Habana, Avenida Universidad, s/n, e/G y Ronda, C.P. 10600 C. de La Habana (Cuba); Cauich-Rodríguez, Juan V. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Cervantes-Uc, José M., E-mail: manceruc@cicy.mx [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico)

2014-07-01

The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone–water than that obtained for methanol–water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol–water system containing MPS at 3 wt.% provides the better results during silanization process of HA. - Highlights: • Effect of MPS concentration and solvents during HA silanization was studied. • Silanization rendered HA has lower crystallinity compared to untreated HA. • Silicon concentration was higher for acetone than that obtained using methanol. • Methanol–water system containing MPS at 3 wt.% provides the better results.

Cytotoxicity and genotoxicity property of hydroxyapatite-mullite eluates.

Science.gov (United States)

Kalmodia, Sushma; Sharma, Vyom; Pandey, Alok K; Dhawan, Alok; Basu, Bikramjit

2011-02-01

Long-term biomedical applications of implant materials may cause osteolysis, aseptic losing and toxicity. Therefore, we investigated the cytotoxic and genotoxic potential of hydroxyapatite (HA) mullite eluates in L929 mouse fibroblast cells. The spark plasma sintered HA-20% mullite biocomposite (HA20M) were ground using mortar and pestle as well as ball milling. The cells were exposed for 6 h to varying concentrations (10, 25, 50, 75 and 100%) of the eluates of HA-20% mullite (87 nm), HA (171 nm) and mullite (154 nm). The scanning electron microscopy and MTT assay revealed the concentration dependent toxicity of H20M eluate at and above 50%. The analysis of the DNA damaging potential of HA, mullite and HA20M eluates using Comet assay demonstrated a significant DNA damage by HA20M which was largely related to the presence of mullite. The results collectively demonstrate the cytotoxic and genotoxic potential of HA20M eluate in L929 cells is dependent on particle size, concentration and composition.

Support for the initial attachment, growth and differentiation of MG-63 cells: a comparison between nano-size hydroxyapatite and micro-size hydroxyapatite in composites

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Filová E

2014-08-01

Full Text Available Elena Filová,1 Tomáš Suchý,2,3 Zbynek Sucharda,2 Monika Šupová,2 Margit Žaloudková,2 Karel Balík,2 Vera Lisá,1 Miroslav Šlouf,4 Lucie Bacáková11Department of Biomaterials and Tissue Engineering, Institute of Physiology, 2Department of Composite and Carbon Materials, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, 3Laboratory of Biomechanics, Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, CTU in Prague, 4Department of Morphology and Rheology of Polymer Materials, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech RepublicAbstract: Hydroxyapatite (HA is considered to be a bioactive material that favorably influences the adhesion, growth, and osteogenic differentiation of osteoblasts. To optimize the cell response on the hydroxyapatite composite, it is desirable to assess the optimum concentration and also the optimum particle size. The aim of our study was to prepare composite materials made of polydimethylsiloxane, polyamide, and nano-sized (N or micro-sized (M HA, with an HA content of 0%, 2%, 5%, 10%, 15%, 20%, 25% (v/v (referred to as N0–N25 or M0–M25, and to evaluate them in vitro in cultures with human osteoblast-like MG-63 cells. For clinical applications, fast osseointegration of the implant into the bone is essential. We observed the greatest initial cell adhesion on composites M10 and N5. Nano-sized HA supported cell growth, especially during the first 3 days of culture. On composites with micro-size HA (2%–15%, MG-63 cells reached the highest densities on day 7. Samples M20 and M25, however, were toxic for MG-63 cells, although these composites supported the production of osteocalcin in these cells. On N2, a higher concentration of osteopontin was found in MG-63 cells. For biomedical applications, the concentration range of 5%–15% (v/v nano-size or micro-size HA seems to be optimum

Synthesis of hydroxyapatite/multi-walled carbon nanotubes for the removal of fluoride ions from solution

Energy Technology Data Exchange (ETDEWEB)

Ruan, Zhongyuan; Tian, Yaxi [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Ruan, Jifu [Chemistry Teaching and Research Group, No.1 Middle School of Queshan, Henan 463200 (China); Cui, Guijia; Iqbal, Kanwal; Iqbal, Anam [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Ye, Herui; Yang, Zhangzhong [Northwest Regional Office of Nuclear and Radiation Safety, Ministry of Environmental Protection, Lanzhou 730000 (China); Yan, Shiqiang, E-mail: yansq@lzu.edu.cn [College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

2017-08-01

Graphical abstract: Hydroxyapatite nucleated and grown on Multi-walled carbon nanotubes (HA-MWCNTs) showed enhanced fluoride removal performance. - Highlights: • Noval HA nanoparticles and HA-MWCNTs composites were successfully synthesized for the first time. • The synthesized HA-MWCNTs composites exhibited a higher defluoridation capacity of 39.22 mg g{sup −1}. • It could reduced the fluoride concentration of the real waste water from 8.79 mg L{sup −1} to approximately 0.25 mg L{sup −1}. - Abstract: A novel composite material, hydroxyapatite (HA)-multi-walled carbon nanotubes (MWCNTs), was prepared using a simple in-situ sol-gel method, and was used for the first time to remove fluoride from water. The novel HA-MWCNTs were characterized using TEM, FT-IR, BET and XRD analysis. The TEM and SAED results revealed that the MWCNTs were uniformly encapsulated by hydroxyapatite nanoparticles. The synthesized HA-MWCNTs had a high specific surface area (180.504 m{sup 2} g{sup −1}), with an average pore width (14.607 nm) and pore volume (0.774 cm{sup 3} g{sup −1}), which produced a defluoridation capacity (DC) of 30.22 mgF{sup −} g{sup −1}. This value was greater than unmodified hydroxyapatite (HA), which exhibited a larger specific surface area (172.233 m{sup 2} g{sup −1}) and an excellent DC of 17.80 mgF{sup −} g{sup −1}. A number of pertinent parameters that could affect the defluoridation performance of the HA/MWCNTs including weight ratios of the two key materials, solution pH and competing anions were carefully and comprehensively examined. It was found that the adsorption results followed the Langmuir and Freundlich isotherm model, and the sorption kinetics of the F{sup −} appeared to exhibit a pseudo second order. Moreover, the adsorption reaction was spontaneous and endothermic and appeared to exhibit a higher initial adsorption rate. This reaction appeared to occur result from both anion exchange and electrostatic interactions. When the

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

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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.

Electro-chemical deposition of nano hydroxyapatite-zinc coating on titanium metal substrate.

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El-Wassefy, N A; Reicha, F M; Aref, N S

2017-08-13

Titanium is an inert metal that does not induce osteogenesis and has no antibacterial properties; it is proposed that hydroxyapatite coating can enhance its bioactivity, while zinc can contribute to antibacterial properties and improve osseointegration. A nano-sized hydroxyapatite-zinc coating was deposited on commercially pure titanium using an electro-chemical process, in order to increase its surface roughness and enhance adhesion properties. The hydroxyapatite-zinc coating was attained using an electro-chemical deposition in a solution composed of a naturally derived calcium carbonate, di-ammonium hydrogen phosphate, with a pure zinc metal as the anode and titanium as the cathode. The applied voltage was -2.5 for 2 h at a temperature of 85 °C. The resultant coating was characterized for its surface morphology and chemical composition using a scanning electron microscope (SEM), energy dispersive x-ray spectroscope (EDS), and Fourier transform infrared (FT-IR) spectrometer. The coated specimens were also evaluated for their surface roughness and adhesion quality. Hydroxyapatite-zinc coating had shown rosette-shaped, homogenous structure with nano-size distribution, as confirmed by SEM analysis. FT-IR and EDS proved that coatings are composed of hydroxyapatite (HA) and zinc. The surface roughness assessment revealed that the coating procedure had significantly increased average roughness (Ra) than the control, while the adhesive tape test demonstrated a high-quality adhesive coat with no laceration on tape removal. The developed in vitro electro-chemical method can be employed for the deposition of an even thickness of nano HA-Zn adhered coatings on titanium substrate and increases its surface roughness significantly.

Synthesis and characterization of hydroxyapatite-gelatine composite materials for orthopaedic application

International Nuclear Information System (INIS)

Yanovska, A.; Kuznetsov, V.; Stanislavov, A.; Husak, E.; Pogorielov, M.; Starikov, V.; Bolshanina, S.; Danilchenko, S.

2016-01-01

The composite materials based on hydroxyapatite (HA) and gelatine (Gel) with addition of silver and zirconium oxide were obtained. The study investigates a combination of low powered ultrasonic irradiation and low concentration of gelatine in the co-precipitation synthesis. These composites have different weight ratios of organic/inorganic components and may be synthesized in two ways: simple mixing and co-precipitation. Both of which were compared. The estimation of porosity, in vivo testing, surface morphology and phase composition as well as the IR-analysis were provided. Hydroxyapatite was the main crystalline phase in obtained composites. While around powdered HA-Gel composite the connective tissue capsule is formed without bone tissue formation, HA-Gel-Ag porous composite implantation leads to formation of new bone tissue and activation of cell proliferation. Addition of silver ions into composite material allows decreasing inflammation on the first stage of implantation and has positive effect on bone tissue formation. Some of the obtained composite materials containing silver or ZrO_2 are biocompatible. bio-resorbable and osteoconductive with high level of porosity (75–85%). - Highlights: • Hydroxyapatite-gelatine composites with addition of Ag"+ and ZrO_2 were obtained. • Composites were synthesized in two ways: simple mixing and co-precipitation. • Co-precipitation synthesis combined ultrasonic treatment and low concentration of gelatine. • Obtained composites have different weight ratios of organic/inorganic components. • Some composites are osteoconductive and all of them have high level of porosity (75–85%).

EDTA assisted synthesis of hydroxyapatite nanoparticles for electrochemical sensing of uric acid

International Nuclear Information System (INIS)

Kanchana, P.; Sekar, C.

2014-01-01

Hydroxyapatite nanoparticles have been synthesized using EDTA as organic modifier by a simple microwave irradiation method and its application for the selective determination of uric acid (UA) has been demonstrated. Electrochemical behavior of uric acid at HA nanoparticle modified glassy carbon electrode (E-HA/GCE) has been investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), linear sweep voltammetry (LSV) and amperometry. The E-HA modified electrode exhibits efficient electrochemical activity towards uric acid sensing without requiring enzyme or electron mediator. Amperometry studies revealed that the fabricated electrode has excellent sensitivity for uric acid with the lowest detection limit of 142 nM over a wide concentration range from 1 × 10 −7 to 3 × 10 −5 M. Moreover, the studied E-HA modified GC electrode exhibits a good reproducibility and long-term stability and an admirable selectivity towards the determination of UA even in the presence of potential interferents. The analytical performance of this sensor was evaluated for the detection of uric acid in human urine and blood serum samples. - Highlights: • EDTA- hydroxyapatite (HA) nanoparticles have been synthesized by microwave irradiation method. • A novel amperometric Uric Acid biosensor has been fabricated using E-HA/GCE. • The fabricated sensor exhibits a wide linear range, good stability and high reproducibility. • The sensor was applied for the detection of UA in human blood serum and urine

In vitro and in vivo studies of lead immobilization by synthetic hydroxyapatite

International Nuclear Information System (INIS)

Arnich, Nathalie; Lanhers, Marie-Claire; Laurensot, Franck; Podor, Renaud; Montiel, Antoine; Burnel, Daniel

2003-01-01

Lead immobilization by solid hydroxyapatite significantly reduces lead concentration and bioavailability in water. - Apatite appears a useful compound for removing lead from water, due to its ability to immobilize the metal by precipitation. In dilute solution, dissolved hydroxyapatite [HA, Ca 10 (PO 4 ) 6 (OH) 2 ] provided phosphates that were reactive with aqueous lead (molar ratio HA/Pb=1/10) forming precipitates at around pH 6. These dissolved at a more acidic pH (3). Solid HA in contact with Pb 2+ ions, led to the formation of pyromorphite [Pb 10 (PO 4 ) 6 (OH) 2 ], identified by X-ray diffraction and insoluble at pH tested (3-8). The amount of pyromorphite increased with the weight ratio of HA/Pb. When this one increased from 1 to 1000, lead precipitated as pyromorphite rose from 19 to 99%. In vivo experiments on rats confirmed the in vitro results. In fact, lead bioavailability assessed by intestinal perfusion was unchanged in the presence of dissolved HA, whereas it was significantly lower in the presence of solid HA, evaluated by gastric intubation, at a weight ratio equal to 10 (amount of lead absorbed decreased by 60%). Apatite could be an effective means of immobilizing lead in drinking or sewage, since accidental pyromorphite ingestion does not yield bioavailable lead

Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: promising bone implant materials.

Science.gov (United States)

Oyefusi, Adebola; Olanipekun, Opeyemi; Neelgund, Gururaj M; Peterson, Deforest; Stone, Julia M; Williams, Ebonee; Carson, Laura; Regisford, Gloria; Oki, Aderemi

2014-11-11

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

Energy Technology Data Exchange (ETDEWEB)

Ozeki, K., E-mail: kazuhide.ozeki.365@vc.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Aoki, H. [International Apatite Institute Co., Ltd., 2-12-9, Misaki-cho, Chiyoda-ku, Tokyo 101-0061 (Japan)

2017-03-01

Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water. In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10 nm Ti intermediate layers was > 79% and 68%, respectively, in the visible light wavelength region (400–700 nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7 MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0 ± 2.4 ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3 ± 1.1 ppb. - Highlights: • Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. • A thin Ti intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film. • The adhesion strength of the HA films with the Ti intermediate layer increased with decreasing thickness of the Ti layer.

Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

International Nuclear Information System (INIS)

Ozeki, K.; Masuzawa, T.; Aoki, H.

2017-01-01

Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water. In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10 nm Ti intermediate layers was > 79% and 68%, respectively, in the visible light wavelength region (400–700 nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7 MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0 ± 2.4 ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3 ± 1.1 ppb. - Highlights: • Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. • A thin Ti intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film. • The adhesion strength of the HA films with the Ti intermediate layer increased with decreasing thickness of the Ti layer.

SCAFFOLD DARI BOVINE HYDROXYAPATITE DENGAN POLY VYNIALCHOHOL COATING

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Alva Edy Tontowi, Punto Dewo, Endang Tri Wahyuni, dan Joko Triyono

2012-06-01

Full Text Available In Indonesia, it is about 40% patients with hard tissue defect due to ostheoporosis, cancer or accidents and therest are defect since they have born.For many years, efforts for recovering have been done by transplantation orimplantation methods.Transplantation is more appropriate butit is not sustain because of limited donor, whileimplantation using synthetic materials such as bioceramics scaffoldis expensive due to import and the scaffold iseasier to break which does not match to the medical requirements.The research therefore has been addressed to thisissue. Local bovine hydroxyapatite (bHAscaffold has been used as thebase material and poly vynilalchohol (PVAas a coating material.The bHA scaffold was prepared by cutting a fresh bovine bone in the size of 5mmx5mmx5mmand boil it in a distilled water to remove its organic material. It was then heated up at 900 oC for 2 hours infurnace to obtain bovine hydroxyapatite scaffold (bHA. Coating process has been carried out by dip coating of thebHAscaffold in PVA solution.

{sup 166} Ho-HA Evaluation as therapeutic agent for rheumatoid arthritis treatment; Evaluacion de {sup 166}Ho-Ha como agente terapeutico en el tratamiento de la artritis reumatoidea

Energy Technology Data Exchange (ETDEWEB)

Chandia, M; Errazu, X [Comision Chilena de Energia Nuclear, Santiago (Chile); Mendoza, P [Departamento de Medicina Nuclear, Hospital Militar, Santiago (Chile); Troncoso, F [Comision Chilena de Energia Nuclear, Santiago (Chile); Jofre, J; Sierralta, P [Departamento de Medicina Nuclear, Hospital Militar, Santiago (Chile)

2003-01-01

Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This lead to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate {sup 166}Ho-Hydroxyapatite ({sup 166} Ho-HA) as potential radiopharmaceutical for the syntomatic treatment of chronic and acute arthritis Materials and Methods: {sup 166}Holmiun was produced by irradiation of Ho{sub 2}O{sub 3} at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthetized. Its labelling and quality controls follows the internationally accepted procedures. An antigen arthritis was induced to eight New Zealand rabbits with the {sup 166}Ho-HA radiochemical being administred thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon clinical improvement and images from the inflamated articulation using {sup 67}Ga citrate before and after {sup 166} Ho-HA injection. Results: The radiochemical purity of the innoculated compound was greater than 98% as measured under sterility conditions. Clinically, an inflamation reduction (2 cm), appetite improvement and general well being was observed. The {sup 166} Ho-HA distribution and localization was monitored using gamma camera images taken at 4 and 24 h. There was no evidence of extraarticular leakage. From the {sup 67}Ga citrate imaging, the acute group shows an overall improvement of well being corresponding to a lesser uptake at the inflamated articulation, regarding to the chronic group. The {sup 166}Ho-HA double dosis, compared to the single dosis, suggest a reduced uptake of {sup 67}Ga citrate at the inflamated tissue, meaning an increased therapeutic effect. Conclusions: {sup 166} Ho-HA is usefull as therapeutic agent for the syntomatic treatment of rheumatoideal arthritis

Synthesis of hydroxyapatite/multi-walled carbon nanotubes for the removal of fluoride ions from solution

Science.gov (United States)

Ruan, Zhongyuan; Tian, Yaxi; Ruan, Jifu; Cui, Guijia; Iqbal, Kanwal; Iqbal, Anam; Ye, Herui; Yang, Zhangzhong; Yan, Shiqiang

2017-08-01

A novel composite material, hydroxyapatite (HA)-multi-walled carbon nanotubes (MWCNTs), was prepared using a simple in-situ sol-gel method, and was used for the first time to remove fluoride from water. The novel HA-MWCNTs were characterized using TEM, FT-IR, BET and XRD analysis. The TEM and SAED results revealed that the MWCNTs were uniformly encapsulated by hydroxyapatite nanoparticles. The synthesized HA-MWCNTs had a high specific surface area (180.504 m2 g-1), with an average pore width (14.607 nm) and pore volume (0.774 cm3 g-1), which produced a defluoridation capacity (DC) of 30.22 mgF- g-1. This value was greater than unmodified hydroxyapatite (HA), which exhibited a larger specific surface area (172.233 m2 g-1) and an excellent DC of 17.80 mgF- g-1. A number of pertinent parameters that could affect the defluoridation performance of the HA/MWCNTs including weight ratios of the two key materials, solution pH and competing anions were carefully and comprehensively examined. It was found that the adsorption results followed the Langmuir and Freundlich isotherm model, and the sorption kinetics of the F- appeared to exhibit a pseudo second order. Moreover, the adsorption reaction was spontaneous and endothermic and appeared to exhibit a higher initial adsorption rate. This reaction appeared to occur result from both anion exchange and electrostatic interactions. When the HA-MWCNTs (MH6) were at an adsorbent dose of 2.0 g L-1, they were able to decrease the fluoride concentration of actual nuclear industry wastewater from 8.79 mg L-1 to about 0.25 mg L-1 (97.15% removal efficiency). The experimental results of this study showed that the HA-MWCNTs composites have application potential for the removal of fluoride ions from wastewater.

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method: bonding to titanium and scanning electron microscopy.

Science.gov (United States)

Tredwin, Christopher J; Georgiou, George; Kim, Hae-Won; Knowles, Jonathan C

2013-05-01

Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) production has been characterised and optimised by the sol-gel method and the dissolution and biological properties of these materials were investigated. It was the objective of this study to investigate the potential bond strength and interaction of these materials with titanium. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethyl phosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the FHA and FA sol-gels. Using a spin coating technique the sol-gels were coated onto commercially pure titanium disks and crystallised at various temperatures. Using scanning electron microscopy (SEM) and elemental analysis, the surface characteristics, coating thickness and interaction of the Ti substrate and coating were investigated. The bond strengths of the coating to the Ti were investigated using an Instron Universal Load Testing Machine. Statistical analysis was performed with a two-way analysis of variance and post hoc testing with a Bonferroni correction. (1) Coating speed inversely influenced the coating thickness. (2) Increasing fluoride ion substitution and heating temperature significantly increased bond strength and (3) increasing fluoride ion substitution increased the coating thickness. FHA and FA synthesised using the sol-gel technique may offer a superior alternative to coating titanium implants with HA and plasma spraying. HA, FHA and FA materials synthesised by the sol-gel method may also have a use as bone grafting materials. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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.

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.

SINTERING EFFECTS ON THE DENSIFICATION OF NANOCRYSTALLINE HYDROXYAPATITE

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M. Amiriyan

2011-06-01

Full Text Available The effects of sintering profiles on the densification behaviour of synthesized nanocrystalline hydroxyapatite (HA powder were investigated in terms of phase stability and mechanical properties. A wet chemical precipitation method was successfully employed to synthesize a high purity and single phase HA powder. Green HA compacts were prepared and subjected to sintering in air atmosphere over a temperature range of 700° C to 1300° C. In this study two different holding times were compared, i.e. 1 minute versus the standard 120 minutes. The results revealed that the 1 minute holding time sintering profile was indeed effective in producing a HA body with high density of 98% theoretical when sintered at 1200° C. High mechanical properties such as fracture toughness of 1.41 MPa.m1/2 and hardness of 9.5 GPa were also measured for HA samples sintered under this profile. Additionally, XRD analysis indicated that decomposition of the HA phase during sintering at high temperatures was suppressed.

Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery

Energy Technology Data Exchange (ETDEWEB)

Hahn, Byung-Dong, E-mail: cera72@kims.re.kr [Functional Ceramics Group, Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon, Gyeong-Nam, 641-010 (Korea, Republic of); Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Kim, Jong-Woo; Ahn, Cheol-Woo [Functional Ceramics Group, Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon, Gyeong-Nam, 641-010 (Korea, Republic of); Kim, Hyoun-Ee [School of Materials Science and Engineering, Seoul National University, San 56-1 Sillim-Dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Yoon, Byung-Ho; Jung, In-Kwon [GENOSS, Gyeonggi R and DB Center, Iui-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 443-270 (Korea, Republic of)

2013-10-15

Polyetheretherketone (PEEK) has attracted much interest as biomaterial for interbody fusion cages due to its similar stiffness to bone and good radio-transparency for post-op visualization. Hydroxyapatite (HA) coating stimulates bone growth to the medical implant. The objective of this work is to make an implant consisting of biocompatible PEEK with an osteoconductive HA surface for spinal or orthopedic applications. Highly dense and well-adhered HA coating was developed on medical-grade PEEK using aerosol deposition (AD) without thermal degradation of the PEEK. The HA coating had a dense microstructure with no cracks or pores, and showed good adhesion to PEEK at adhesion strengths above 14.3 MPa. The crystallinity of the HA coating was remarkably enhanced by hydrothermal annealing as post-deposition heat-treatment. In addition, in vitro and in vivo biocompatibility of PEEK, in terms of cell adhesion morphology, cell proliferation, differentiation, and bone-to-implant contact ratio, were remarkably enhanced by the HA coating through AD.

Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery

International Nuclear Information System (INIS)

Hahn, Byung-Dong; Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Kim, Jong-Woo; Ahn, Cheol-Woo; Kim, Hyoun-Ee; Yoon, Byung-Ho; Jung, In-Kwon

2013-01-01

Polyetheretherketone (PEEK) has attracted much interest as biomaterial for interbody fusion cages due to its similar stiffness to bone and good radio-transparency for post-op visualization. Hydroxyapatite (HA) coating stimulates bone growth to the medical implant. The objective of this work is to make an implant consisting of biocompatible PEEK with an osteoconductive HA surface for spinal or orthopedic applications. Highly dense and well-adhered HA coating was developed on medical-grade PEEK using aerosol deposition (AD) without thermal degradation of the PEEK. The HA coating had a dense microstructure with no cracks or pores, and showed good adhesion to PEEK at adhesion strengths above 14.3 MPa. The crystallinity of the HA coating was remarkably enhanced by hydrothermal annealing as post-deposition heat-treatment. In addition, in vitro and in vivo biocompatibility of PEEK, in terms of cell adhesion morphology, cell proliferation, differentiation, and bone-to-implant contact ratio, were remarkably enhanced by the HA coating through AD.

Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery

Science.gov (United States)

Hahn, Byung-Dong; Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Kim, Jong-Woo; Ahn, Cheol-Woo; Kim, Hyoun-Ee; Yoon, Byung-Ho; Jung, In-Kwon

2013-10-01

Polyetheretherketone (PEEK) has attracted much interest as biomaterial for interbody fusion cages due to its similar stiffness to bone and good radio-transparency for post-op visualization. Hydroxyapatite (HA) coating stimulates bone growth to the medical implant. The objective of this work is to make an implant consisting of biocompatible PEEK with an osteoconductive HA surface for spinal or orthopedic applications. Highly dense and well-adhered HA coating was developed on medical-grade PEEK using aerosol deposition (AD) without thermal degradation of the PEEK. The HA coating had a dense microstructure with no cracks or pores, and showed good adhesion to PEEK at adhesion strengths above 14.3 MPa. The crystallinity of the HA coating was remarkably enhanced by hydrothermal annealing as post-deposition heat-treatment. In addition, in vitro and in vivo biocompatibility of PEEK, in terms of cell adhesion morphology, cell proliferation, differentiation, and bone-to-implant contact ratio, were remarkably enhanced by the HA coating through AD.

Preparation of nano-hydroxyapatite particles with different morphology and their response to highly malignant melanoma cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Li Bo [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China); Guo Bo [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China); West China Eye Center of Huaxi Hospital, Sichuan University, Chengdu 610064 (China); Fan Hongsong [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China)], E-mail: leewave@126.com; Zhang Xingdong [National Engineering Research Center for Biomaterial, Sichuan University, Chengdu 610064 (China)

2008-11-15

To investigate the effects of nano-hydroxyapatite (HA) particles with different morphology on highly malignant melanoma cells, three kinds of HA particles with different morphology were synthesized and co-cultured with highly malignant melanoma cells using phosphate-buffered saline (PBS) as control. A precipitation method with or without citric acid addition as surfactant was used to produce rod-like hydroxyapatite (HA) particles with nano- and micron size, respectively, and a novel oil-in-water emulsion method was employed to prepare ellipse-like nano-HA particles. Particle morphology and size distribution of the as prepared HA powders were characterized by transmission electron microscope (TEM) and dynamic light scattering technique. The nano- and micron HA particles with different morphology were co-cultured with highly malignant melanoma cells. Immunofluorescence analysis and MTT assay were employed to evaluate morphological change of nucleolus and proliferation of tumour cells, respectively. To compare the effects of HA particles on cell response, the PBS without HA particles was used as control. The experiment results indicated that particle nanoscale effect rather than particle morphology of HA was more effective for the inhibition on highly malignant melanoma cells proliferation.

Properties and in vitro biological evaluation of nano-hydroxyapatite/chitosan membranes for bone guided regeneration

Energy Technology Data Exchange (ETDEWEB)

Cheng Xianmiao [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China); Department of Chemistry, Sichuan University, 610064 Chengdu (China); Li Yubao [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China)], E-mail: nic7504@scu.edu.cn; Zuo Yi; Zhang Li [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China); Li Jidong [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China); Department of Chemistry, Sichuan University, 610064 Chengdu (China); Wang Huanan [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, 610064 Chengdu (China)

2009-01-01

Nano-hydroxyapatite(n-HA)/chitosan(CS) composite membranes were prepared by solvent casting and evaporation methods for the function of guided bone regeneration (GBR). The effect of n-HA content and solvent evaporation temperature on the properties of the composite membranes was studied. The n-HA/CS membranes were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, swelling measurement, mechanical test, cell culture and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylte-2H-tetrazolium bromide) assay. The results show that the surface roughness and micropores of the composite membranes increase with the rise of n-HA content, suitable for adhesion, crawl and growth of cells. The hydroxyapatite holds nano size and distributes uniformly in the composite membranes. Chemical bond interaction exists between Ca ions and -OH groups of n-HA and -NH{sub 2} or -OH groups of CS. The n-HA content and solvent evaporation temperature have obvious influence on the swelling ratio, tensile strength and elongation rate of the composite membranes. Cell culture and MTT assays show that n-HA and its content can affect the proliferation of cells. The n-HA/CS composite membranes have no negative effect on the cell morphology, viability and proliferation and possess good biocompatibility. This study makes the n-HA/CS composite membrane be a prospective biodegradable GBR membrane for future applications.

Properties and in vitro biological evaluation of nano-hydroxyapatite/chitosan membranes for bone guided regeneration

International Nuclear Information System (INIS)

Cheng Xianmiao; Li Yubao; Zuo Yi; Zhang Li; Li Jidong; Wang Huanan

2009-01-01

Nano-hydroxyapatite(n-HA)/chitosan(CS) composite membranes were prepared by solvent casting and evaporation methods for the function of guided bone regeneration (GBR). The effect of n-HA content and solvent evaporation temperature on the properties of the composite membranes was studied. The n-HA/CS membranes were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, swelling measurement, mechanical test, cell culture and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylte-2H-tetrazolium bromide) assay. The results show that the surface roughness and micropores of the composite membranes increase with the rise of n-HA content, suitable for adhesion, crawl and growth of cells. The hydroxyapatite holds nano size and distributes uniformly in the composite membranes. Chemical bond interaction exists between Ca ions and -OH groups of n-HA and -NH 2 or -OH groups of CS. The n-HA content and solvent evaporation temperature have obvious influence on the swelling ratio, tensile strength and elongation rate of the composite membranes. Cell culture and MTT assays show that n-HA and its content can affect the proliferation of cells. The n-HA/CS composite membranes have no negative effect on the cell morphology, viability and proliferation and possess good biocompatibility. This study makes the n-HA/CS composite membrane be a prospective biodegradable GBR membrane for future applications

A Simple Method to Functionalize the Surface of Plasma Electrolytic Oxidation Produced TiO2 Coatings for Growing Hydroxyapatite

International Nuclear Information System (INIS)

Teng, Huan-Ping; Yang, Chia-Jung; Lin, Jia-Fu; Huang, Yu-Hsin; Lu, Fu-Hsing

2016-01-01

Highlights: • TiO 2 coatings with porous surfaces were produced by plasma electrolytic oxidation. • Simple pre-immersion in K 2 HPO 4 could functionalize the surfaces of the TiO 2 . • Such pre-immersion enhanced substantially the growth of hydroxyapatite in SBF. • Growth mechanisms of hydroxyapatite via the pre-immersion have been proposed. • MTT assay shows great osteoblast-like cell activity on the obtained hydroxyapatite. - Abstract: Conventionally, hydrothermal treatment was often used to modify the TiO 2 surface prior to the growth of hydroxyapatite (HA) that is one of the most important implant biomaterials. In this work, a simple pre-immersion of the obtained TiO 2 in a weak base, instead of the conventionally high pressure-temperature hydrothermal pre-treatment, was conducted prior to the growth of HA. Firstly, anatase TiO 2 coatings with porous surfaces were produced by plasma electrolytic oxidation with optimized processing parameters. X-ray diffraction patterns and field-emission microscopy reveal that the anatase TiO 2 films with porous surfaces were produced by plasma electrolytic oxidation. Subsequently, the films were pre-immersed in 0.1–2 M K 2 HPO 4 solutions for only 10 min. Fourier transform infrared spectroscopy shows that the −OH functional groups were generated after such pre-immersion, which could enhance significantly the growth of a single phase of HA in simulated body fluid (SBF). Growth mechanisms of HA via the pre-immersion treatment and soaking in SBF have been proposed. Moreover, the proliferation rate and attachment of the MG-63 osteoblast cells were greatly enhanced on the obtained HA compared to that without the immersion pre-treatment from the MTT assay and morphology analyses. This simple immersion pre-treatment evidently provides an easy route for the growth of HA and has great potential for biomedical applications.

Investigation of microstructure and mechanical properties of PLLA/HA system

Science.gov (United States)

Nik Hanyn N., H.; Ahmad, K. Z. Ku; Yusof, Mohd Reusmaazran; Kamarolzaman, A. A.

2017-12-01

The poly(L-lactide) (PLLA), carboxymethyl starch (CMS) and hydroxyapatite (HAp) nanofibers have been prepared by electrospinning technique. The PLLA/CMS formulations applied at various voltage were studied for electrospinning into nanofibers. It was found that the morphology of the fibers became finer with the increment of voltage applied. The formulation with 10 kV voltage was selected as it shows promising result based on the morphology observation. The PLLA/CMS/HA formulation with HA loading concentration (i.e. 0.25, 0.50, 0.75 and 1.00 wt%) was fabricated in the next stage, and the effect of HA addition was studied. Observation showed that the electrospun nanofibers' diameters were reduced with the addition of HAp concentration from 0.25 wt% HAp to 1.00 wt% Hap.

Bacterial Cellulose-Hydroxyapatite Nanocomposites for Bone Regeneration

Directory of Open Access Journals (Sweden)

S. Saska

2011-01-01

Full Text Available The aim of this study was to develop and to evaluate the biological properties of bacterial cellulose-hydroxyapatite (BC-HA nanocomposite membranes for bone regeneration. Nanocomposites were prepared from bacterial cellulose membranes sequentially incubated in solutions of CaCl2 followed by Na2HPO4. BC-HA membranes were evaluated in noncritical bone defects in rat tibiae at 1, 4, and 16 weeks. Thermogravimetric analyses showed that the amount of the mineral phase was 40%–50% of the total weight. Spectroscopy, electronic microscopy/energy dispersive X-ray analyses, and X-ray diffraction showed formation of HA crystals on BC nanofibres. Low crystallinity HA crystals presented Ca/P a molar ratio of 1.5 (calcium-deficient HA, similar to physiological bone. Fourier transformed infrared spectroscopy analysis showed bands assigned to phosphate and carbonate ions. In vivo tests showed no inflammatory reaction after 1 week. After 4 weeks, defects were observed to be completely filled in by new bone tissue. The BC-HA membranes were effective for bone regeneration.

Preparation and corrosion resistance of magnesium phytic acid/hydroxyapatite composite coatings on biodegradable AZ31 magnesium alloy.

Science.gov (United States)

Zhang, Min; Cai, Shu; Zhang, Feiyang; Xu, Guohua; Wang, Fengwu; Yu, Nian; Wu, Xiaodong

2017-06-01

In this work, a magnesium phytic acid/hydroxyapatite composite coating was successfully prepared on AZ31 magnesium alloy substrate by chemical conversion deposition technology with the aim of improving its corrosion resistance and bioactivity. The influence of hydroxyapatite (HA) content on the microstructure and corrosion resistance of the coatings was investigated. The results showed that with the increase of HA content in phytic acid solution, the cracks on the surface of the coatings gradually reduced, which subsequently improved the corrosion resistance of these coated magnesium alloy. Electrochemical measurements in simulated body fluid (SBF) revealed that the composite coating with 45 wt.% HA addition exhibited superior surface integrity and significantly improved corrosion resistance compared with the single phytic acid conversion coating. The results of the immersion test in SBF showed that the composite coating could provide more effective protection for magnesium alloy substrate than that of the single phytic acid coating and showed good bioactivity. Magnesium phytic acid/hydroxyapatite composite, with the desired bioactivity, can be synthesized through chemical conversion deposition technology as protective coatings for surface modification of the biodegradable magnesium alloy implants. The design idea of the new type of biomaterial is belong to the concept of "third generation biomaterial". Corrosion behavior and bioactivity of coated magnesium alloy are the key issues during implantation. In this study, preparation and corrosion behavior of magnesium phytic acid/hydroxyapatite composite coatings on magnesium alloy were studied. The basic findings and significance of this paper are as follows: 1. A novel environmentally friendly, homogenous and crack-free magnesium phytic acid/hydroxyapatite composite coating was fabricated on AZ31 magnesium alloy via chemical conversion deposition technology with the aim of enhancing its corrosion resistance and

Dispersion of carbon nanotubes in hydroxyapatite powder by in situ chemical vapor deposition

International Nuclear Information System (INIS)

Li Haipeng; Wang Lihui; Liang, Chunyong; Wang Zhifeng; Zhao Weimin

2010-01-01

In the present work, we use chemical vapor deposition of methane to disperse carbon nanotubes (CNTs) within hydroxyapatite (HA) powder. The effect of different catalytic metal particles (Fe, Ni or Co) on the morphological and structural development of the powder and dispersion of CNTs in HA powder was investigated. The results show that the technique is effective in dispersing the nanotubes within HA powder, which simultaneously protects the nanotubes from damage. The results can have important and promising speculations for the processing of CNT-reinforced HA-matrix composites in general.

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 ...

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.

Isolation and Characterization of Nano-Hydroxyapatite from Salmon Fish Bone

Directory of Open Access Journals (Sweden)

Jayachandran Venkatesan

2015-08-01

Full Text Available Nano-Hydroxyapatite (nHA was isolated from salmon bone by alkaline hydrolysis. The resulting nHA was characterized using several analytical tools, including thermogravimetric analysis (TGA, Fourier transform infrared spectroscopy (FT-IR, X-ray diffraction analysis (XRD, scanning electron microscopy (SEM and transmission electron microscopy (TEM, to determine the purity of the nHA sample. The removal of organic matter from the raw fish was confirmed by TGA. FT-IR confirmed the presence of a carbonated group and the similarities to synthetic Sigma HA. XRD revealed that the isolated nHA was amorphous. Microscopy demonstrated that the isolated nHA possessed a nanostructure with a size range of 6–37 nm. The obtained nHA interacted with mesenchymal stem cells (MSCs and was non-toxic. Increased mineralization was observed for nHA treated MSCs compared to the control group. These results suggest that nHA derived from salmon is a promising biomaterial in the field of bone tissue engineering.

Preparation and cellular response of porous A-type carbonated hydroxyapatite nanoceramics

International Nuclear Information System (INIS)

Li Bo; Liao Xiaoling; Zheng Li; He Huawei; Wang Hong; Fan Hongsong; Zhang Xingdong

2012-01-01

Microwave sintering using the activated carbon as embedding material was applied in preparation of porous A-type carbonated hydroxyapatite ceramics with nano(nCHA) and submicron (mCHA) structure. By examining the linear shrinkages and the compressive strengths of samples at different temperatures, a suitable microwave sintering temperature was achieved. The microwave sintering method was successfully used to prepare A-type CHA with nano or submicron structure, and the mechanism of the formation of A-type carbonate groups was discussed also. Compared with the samples prepared by the conventional sintering method (mHA), the nCHA bioceramics synthesized by the microwave sintering approach had smaller grain size and more uniform microstructure, and showed a compressive strength similar to the conventional samples. In vitro dissolution test proved that nCHA exhibits better degradation property in comparison to pure HA. Rat osteoblasts were cultured with nCHA, mCHA and mHA to evaluate their biocompatibility, and nCHA showed significant enhancement of cells in attachment, proliferation and differentiation. In conclusion, carbonate groups can be easily introduced to HA crystal structure using the activated carbon as embedding material, and microwave sintering is an effective and simple method in preparing A-type CHA with a nanostructure. Results from this in vitro biological study suggest that porous A-type carbonated hydroxyapatite nanoceramics may be a much better candidate for clinical use in terms of bioactivity. - Highlights: ► We prepared porous A-type carbonated hydroxyapatite nanoceramics with microwave sintering. ► We examined physico-chemical characterization and osteoblast response. ► The nanoceramics have a comparable compressive strength to samples with conventional sintering method. ► The nanoceramics enhance degradation property, osteoblast proliferation and differentiation. ► The activated carbon is favorable for preheating samples and providing

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.

Mesoporous Fe{sub 3}O{sub 4}/hydroxyapatite composite for targeted drug delivery

Energy Technology Data Exchange (ETDEWEB)

Gu, Lina; He, Xiaomei; Wu, Zhenyu, E-mail: zhenyuwuhn@sina.com

2014-11-15

Highlights: • Mesoporous Fe{sub 3}O{sub 4}/hydroxyapatite composite was synthesized by a simple, efficient and environmental friendly method. • The prepared material had a large surface area, high pore volume, and good magnetic separability. • DOX-loaded Fe{sub 3}O{sub 4}/hydroxyapatite composite exhibited surprising slow drug release behavior and pH-dependent behavior. - Abstract: In this contribution, we introduced a simple, efficient, and green method of preparing a mesoporous Fe{sub 3}O{sub 4}/hydroxyapatite (HA) composite. The as-prepared material had a large surface area, high pore volume, and good magnetic separability, which made it suitable for targeted drug delivery systems. The chemotherapeutic agent doxorubicin (DOX) was used to investigate the drug release behavior of Fe{sub 3}O{sub 4}/HA composite. The drug release profiles displayed a little burst effect and pH-dependent behavior. The release rate of DOX at pH 5.8 was larger than that at pH 7.4, which could be attributed to DOX protonation in acid medium. In addition, the released DOX concentrations remained at 0.83 and 1.39 μg/ml at pH 7.4 and 5.8, respectively, which indicated slow, steady, and safe release rates. Therefore, the as-prepared Fe{sub 3}O{sub 4}/hydroxyapatite composite could be an efficient platform for targeted anticancer drug delivery.

EDTA assisted synthesis of hydroxyapatite nanoparticles for electrochemical sensing of uric acid

Energy Technology Data Exchange (ETDEWEB)

Kanchana, P.; Sekar, C., E-mail: Sekar2025@gmail.com

2014-09-01

Hydroxyapatite nanoparticles have been synthesized using EDTA as organic modifier by a simple microwave irradiation method and its application for the selective determination of uric acid (UA) has been demonstrated. Electrochemical behavior of uric acid at HA nanoparticle modified glassy carbon electrode (E-HA/GCE) has been investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), linear sweep voltammetry (LSV) and amperometry. The E-HA modified electrode exhibits efficient electrochemical activity towards uric acid sensing without requiring enzyme or electron mediator. Amperometry studies revealed that the fabricated electrode has excellent sensitivity for uric acid with the lowest detection limit of 142 nM over a wide concentration range from 1 × 10{sup −7} to 3 × 10{sup −5} M. Moreover, the studied E-HA modified GC electrode exhibits a good reproducibility and long-term stability and an admirable selectivity towards the determination of UA even in the presence of potential interferents. The analytical performance of this sensor was evaluated for the detection of uric acid in human urine and blood serum samples. - Highlights: • EDTA- hydroxyapatite (HA) nanoparticles have been synthesized by microwave irradiation method. • A novel amperometric Uric Acid biosensor has been fabricated using E-HA/GCE. • The fabricated sensor exhibits a wide linear range, good stability and high reproducibility. • The sensor was applied for the detection of UA in human blood serum and urine.

Synthesis and characterization of hydroxyapatite-gelatine composite materials for orthopaedic application

Energy Technology Data Exchange (ETDEWEB)

Yanovska, A., E-mail: biophy@yandex.ru [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Kuznetsov, V. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Stanislavov, A. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Husak, E. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Pogorielov, M. [Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Starikov, V. [National Technical University ”Kharkov Polytechnic Institute”, 21 Frunze Str., 61002, Kharkov (Ukraine); Bolshanina, S. [Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Danilchenko, S. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine)

2016-11-01

The composite materials based on hydroxyapatite (HA) and gelatine (Gel) with addition of silver and zirconium oxide were obtained. The study investigates a combination of low powered ultrasonic irradiation and low concentration of gelatine in the co-precipitation synthesis. These composites have different weight ratios of organic/inorganic components and may be synthesized in two ways: simple mixing and co-precipitation. Both of which were compared. The estimation of porosity, in vivo testing, surface morphology and phase composition as well as the IR-analysis were provided. Hydroxyapatite was the main crystalline phase in obtained composites. While around powdered HA-Gel composite the connective tissue capsule is formed without bone tissue formation, HA-Gel-Ag porous composite implantation leads to formation of new bone tissue and activation of cell proliferation. Addition of silver ions into composite material allows decreasing inflammation on the first stage of implantation and has positive effect on bone tissue formation. Some of the obtained composite materials containing silver or ZrO{sub 2} are biocompatible. bio-resorbable and osteoconductive with high level of porosity (75–85%). - Highlights: • Hydroxyapatite-gelatine composites with addition of Ag{sup +} and ZrO{sub 2} were obtained. • Composites were synthesized in two ways: simple mixing and co-precipitation. • Co-precipitation synthesis combined ultrasonic treatment and low concentration of gelatine. • Obtained composites have different weight ratios of organic/inorganic components. • Some composites are osteoconductive and all of them have high level of porosity (75–85%).

Novel biopolymer-coated hydroxyapatite foams for removing heavy-metals from polluted water

International Nuclear Information System (INIS)

Vila, M.; Sanchez-Salcedo, S.; Cicuendez, M.; Izquierdo-Barba, I.; Vallet-Regi, Maria

2011-01-01

Highlights: → 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams as potential devices for the treatment of heavy metal ions. → HA stable foams coated with biopolymers. → Feasible advance in development of new, easy to handle and low cost water purifying methods. - Abstract: 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams have been developed as potential devices for the treatment of lead, cadmium and copper contamination of consumable waters. These foams have exhibited a fast and effective ion metal immobilization into the HA structure after an in vitro treatment mimicking a serious water contamination case. To improve HA foam stability at contaminated aqueous solutions pH, as well as its handling and shape integrity the 3D-macroporous foams have been coated with biopolymers polycaprolactone (PCL) and gelatine cross-linked with glutaraldehyde (G/Glu). Metal ion immobilization tests have shown higher and fast heavy metals captured as function of hydrophilicity rate of biopolymer used. After an in vitro treatment, foam morphology integrity is guaranteed and the uptake of heavy metal ions rises up to 405 μmol/g in the case of Pb 2+ , 378 μmol/g of Cu 2+ and 316 μmol/g of Cd 2+ . These novel materials promise a feasible advance in development of new, easy to handle and low cost water purifying methods.

Preparation of nano-hydroxyapatite/poly(l-lactide) biocomposite microspheres

International Nuclear Information System (INIS)

Qiu Xueyu; Han Yadong; Zhuang Xiuli; Chen Xuesi; Li Yuesheng; Jing Xiabin

2007-01-01

Nano-hydroxyapatite (HA)/poly(l-lactide) (PLLA) composite microspheres with relatively uniform size distribution were prepared by a solid-in-oil-in-water (s/o/w) emusion solvent evaporation method. The encapsulation of the HA nanopaticles in microshperes was significantly improved by grafting PLLA on the surface of the HA nanoparticles (p-HA) during emulsion process. This procedure gave a possibility to obtain p-HA/PLLA composite microspheres with uniform morphology and the encapsulated p-HA nanoparticle loading reached up to 40 wt% (33 wt% of pure HA) in the p-HA/PLLA composite microspheres. The microstructure of composite microspheres from core-shell to single phase changed with the variation of p-HA to PLLA ratios. p-HA/PLLA composite microspheres with the diameter range of 2-3 μm were obtained. The entrapment efficiency of p-HA in microspheres could high up to 90 wt% and that of HA was only 13 wt%. Surface and bulk characterizations of the composite microspheres were performed by measurements such as wide angle X-ray diffraction (WAXD), thermal gravimetric analysis (TGA), environmental scanning electron microscope (ESEM) and transmission electron microscopy (TEM)

A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

NARCIS (Netherlands)

Neut, D.; Dijkstra, R. J. B.; Thompson, J. I.; Kavanagh, C.; van der Mei, H. C.; Busscher, H. J.

2015-01-01

A degradable, poly (lactic-co-glycolic acid) (PLGA), gentamicin-loaded prophylactic coating for hydroxyapatite (HA)-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We

First principles study of hydroxyapatite surface

Science.gov (United States)

Slepko, Alexander; Demkov, Alexander A.

2013-07-01

The biomineral hydroxyapatite (HA) [Ca10(PO4)6(OH)2] is the main mineral constituent of mammal bone. We report a theoretical investigation of the HA surface. We identify the low energy surface orientations and stoichiometry under a variety of chemical environments. The surface most stable in the physiologically relevant OH-rich environment is the OH-terminated (1000) surface. We calculate the work function of HA and relate it to the surface composition. For the lowest energy OH-terminated surface we find the work function of 5.1 eV, in close agreement with the experimentally reported range of 4.7 eV-5.1 eV [V. S. Bystrov, E. Paramonova, Y. Dekhtyar, A. Katashev, A. Karlov, N. Polyaka, A. V. Bystrova, A. Patmalnieks, and A. L. Kholkin, J. Phys.: Condens. Matter 23, 065302 (2011), 10.1088/0953-8984/23/6/065302].

The performance of dental pulp stem cells on nanofibrous PCL/gelatin/nHA scaffolds.

NARCIS (Netherlands)

Yang, X.; Yang, F.; Walboomers, X.F.; Bian, Z.; Fan, M.; Jansen, J.A.

2010-01-01

The aim of current study is to investigate the in vitro and in vivo behavior of dental pulp stem cells (DPSCs) seeded on electrospun poly(epsilon-caprolactone) (PCL)/gelatin scaffolds with or without the addition of nano-hydroxyapatite (nHA). For the in vitro evaluation, DNA content, alkaline

Functionalized PCL/HA nanocomposites as microporous membranes for bone regeneration

Energy Technology Data Exchange (ETDEWEB)

Basile, Maria Assunta; Gomez d' Ayala, Giovanna; Malinconico, Mario [Institute for Polymers, Composites and Biomaterials, CNR, Via Campi Flegrei 34, Pozzuoli (Naples) (Italy); Laurienzo, Paola, E-mail: paola.laurienzo@ipcb.cnr.it [Institute for Polymers, Composites and Biomaterials, CNR, Via Campi Flegrei 34, Pozzuoli (Naples) (Italy); Coudane, Jean; Nottelet, Benjamin [Institut des Biomolécules Max Mousseron (IBMM), Artificial Biopolymers Group, CNRS UMR 5247, University of Montpellier 1, Faculty of Pharmacy, 15 Av. C. Flahault, Montpellier 34093 (France); Ragione, Fulvio Della [Department of Biochemistry and Biophysics, Second University of Naples, Via L. De Crecchio 7, Naples (Italy); Oliva, Adriana, E-mail: adriana.oliva@unina2.it [Department of Biochemistry and Biophysics, Second University of Naples, Via L. De Crecchio 7, Naples (Italy)

2015-03-01

In the present work, microporous membranes based on poly(ε-caprolactone) (PCL) and PCL functionalized with amine (PCL-DMAEA) or anhydride groups (PCL-MAGMA) were realized by solvent–non solvent phase inversion and proposed for use in Guided Tissue Regeneration (GTR). Nanowhiskers of hydroxyapatite (HA) were also incorporated in the polymer matrix to realize nanocomposite membranes. Scanning Electron Microscopy (SEM) showed improved interfacial adhesion with HA for functionalized polymers, and highlighted substantial differences in the porosity. A relationship between the developed porous structure of the membrane and the chemical nature of grafted groups was proposed. Compared to virgin PCL, hydrophilicity increases for functionalized PCL, while the addition of HA influences significantly the hydrophilic characteristics only in the case of virgin polymer. A significant increase of in vitro degradation rate was found for PCL-MAGMA based membranes, and at lower extent of PCL-DMAEA membranes. The novel materials were investigated regarding their potential as support for cell growth in bone repair using multipotent mesenchymal stromal cells (MSC) as a model. MSC plated onto the various membranes were analyzed in terms of adhesion, proliferation and osteogenic capacity that resulted to be related to chemical as well as porous structure. In particular, PCL-DMAEA and the relative nanocomposite membranes are the most promising in terms of cell-biomaterial interactions. - Graphical abstract: Functionalized PCL is used to realize nanocomposites with hydroxyapatite (HA) in the form of microporous membranes. The influence of different grafted groups on mechanical properties, in vitro degradation, porous membrane structure and interaction with mesenchymal stromal cells (MSC) is discussed. - Highlights: • Functionalized PCL shows faster in vitro degradation rate. • Functionalized PCL shows superior cell adhesion, proliferation and differentiation. • Nanocomposites based

Functionalized PCL/HA nanocomposites as microporous membranes for bone regeneration

International Nuclear Information System (INIS)

Basile, Maria Assunta; Gomez d'Ayala, Giovanna; Malinconico, Mario; Laurienzo, Paola; Coudane, Jean; Nottelet, Benjamin; Ragione, Fulvio Della; Oliva, Adriana

2015-01-01

In the present work, microporous membranes based on poly(ε-caprolactone) (PCL) and PCL functionalized with amine (PCL-DMAEA) or anhydride groups (PCL-MAGMA) were realized by solvent–non solvent phase inversion and proposed for use in Guided Tissue Regeneration (GTR). Nanowhiskers of hydroxyapatite (HA) were also incorporated in the polymer matrix to realize nanocomposite membranes. Scanning Electron Microscopy (SEM) showed improved interfacial adhesion with HA for functionalized polymers, and highlighted substantial differences in the porosity. A relationship between the developed porous structure of the membrane and the chemical nature of grafted groups was proposed. Compared to virgin PCL, hydrophilicity increases for functionalized PCL, while the addition of HA influences significantly the hydrophilic characteristics only in the case of virgin polymer. A significant increase of in vitro degradation rate was found for PCL-MAGMA based membranes, and at lower extent of PCL-DMAEA membranes. The novel materials were investigated regarding their potential as support for cell growth in bone repair using multipotent mesenchymal stromal cells (MSC) as a model. MSC plated onto the various membranes were analyzed in terms of adhesion, proliferation and osteogenic capacity that resulted to be related to chemical as well as porous structure. In particular, PCL-DMAEA and the relative nanocomposite membranes are the most promising in terms of cell-biomaterial interactions. - Graphical abstract: Functionalized PCL is used to realize nanocomposites with hydroxyapatite (HA) in the form of microporous membranes. The influence of different grafted groups on mechanical properties, in vitro degradation, porous membrane structure and interaction with mesenchymal stromal cells (MSC) is discussed. - Highlights: • Functionalized PCL shows faster in vitro degradation rate. • Functionalized PCL shows superior cell adhesion, proliferation and differentiation. • Nanocomposites based

Laser fabrication of Ag-HA nanocomposites on Ti6Al4V implant for enhancing bioactivity and antibacterial capability

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiangmei; Man, H.C., E-mail: mfhcman@polyu.edu.hk

2017-01-01

For titanium alloy implants, both surface bioactivity and antibacterial infection are the two critical factors in determining the success of clinical implantation of these metallic implants. In the present work, a novel nanocomposite layer of nano-silver-containing hydroxyapatite (Ag-HA) was prepared on the surface of biomedical Ti6Al4V by laser processing. Analysis using SEM, EDS and XRD shows the formation of an Ag-HA layer of about 200 μm fusion bonded to the substrate. Mineralization tests in simulated body fluid (SBF) showed that laser fabricated Ag-HA nanocomposite layer favors the deposition of apatite on the surface of the implants. Antibacterial tests confirmed that all Ag-HA nanocomposite layers can kill bacteria while a higher Ag content would lower the cytocompatibility of these coatings. Cell viability decreases when the Ag content reaches 5% in these coatings, due to the larger amount of Ag leached out, as confirmed by ion release evaluation. Our results reveal that laser fabricated Ag-HA nanocomposite coatings containing 2% Ag show both excellent cytocompatibility and antibacterial capability. - Highlights: • Silver-containing hydroxyapatite (Ag-HA) nanocomposite layer was fabricated on Ti6Al4V by laser technique. • Both bioactivity and antibacterial capability were significantly enhanced compared with bare Ti6Al4V. • Ag-HA nanocomposite coatings containing 2% Ag show both excellent cytocompatibility and antibacterial capability.

Niobium-Doped Hydroxyapatite Bioceramics: Synthesis, Characterization and In Vitro Cytocompatibility

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Nádia S. V. Capanema

2015-07-01

Full Text Available Doping calcium phosphates with ionic species can play an important role in biological responses promoting alkaline phosphatase activity, and, therefore inducing the generation of new bone. Thus, in this study, the synthesis of niobium-doped hydroxyapatite (Nb-HA nanosize particles obtained by the precipitation process in aqueous media followed by thermal treatment is presented. The bioceramics were extensively characterized by X-ray diffraction, wavelength dispersive X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy analysis, transmission electron microscopy, atomic force microscopy and thermal analysis regarding their chemical composition, structure and morphology. The results showed that the precipitate dried at 110 °C was composed of amorphous calcium phosphate and HA, with polidisperse particles ranging from micro to nano dimensions. After the thermal treatment at 900 °C, the bioceramic system evolved predominantly to HA crystalline phase, with evident features of particle sintering and reduction of surface area. Moreover, the addition of 10 mol% of niobium salt precursor during the synthesis indicated the complete incorporation of the Nb(V species in the HA crystals with detectable changes in the original lattice parameters. Furthermore, the incorporation of Nb ions caused a significant refinement on the average particle size of HA. Finally, the preliminary cytocompatibility response of the biomaterials was accessed by human osteoblast cell culture using MTT and resazurin assays, which demonstrated no cytotoxicity of the Nb-alloyed hydroxyapatite. Thus, these findings seem promising for developing innovative Nb-doped calcium phosphates as artificial biomaterials for potential use in bone replacements and repair.

Thermal and structural characterization of synthetic and natural nanocrystalline hydroxyapatite

International Nuclear Information System (INIS)

Sofronia, Ancuta M.; Baies, Radu; Anghel, Elena M.; Marinescu, Cornelia A.; Tanasescu, Speranta

2014-01-01

The aim of this work was to study the thermal stability on heating and to obtain the processing parameters of synthetic and bone-derived hydroxyapatite over temperatures between room temperature and 1400 °C by thermal analysis (thermogravimetry (TG)/differential scanning calorimetry (DSC) and thermo-mechanical analysis—TMA). Structural and surface modifications related to samples origin and calcination temperature were investigated by Fourier transformed infrared (FTIR) and Raman spectroscopy, X-ray diffraction (XRD) and BET method. FTIR spectra indicated that the organic constituents and carbonate are no longer present in the natural sample calcined at 800 °C. Raman spectra highlighted the decomposition products of the hydroxyapatite. The calcination treatment modifies the processes kinetics of the synthetic samples, being able to isolate lattice water desorption processes of decarbonization and the dehydroxylation processes. Shrinkage of calcined synthetic sample increases by 10% compared to uncalcined synthetic powder. From the TMA correlated with TG analysis and heat capacity data it can be concluded that sintering temperature of the synthetic samples should be chosen in the temperature range of the onset of dehydroxylation and the temperature at which oxyapatite decomposition begins. - Highlights: • Specific surface area of HA powder was reduced from 19.2 to 9.5 m 2 /g by calcination. • Raman spectra indicate the presence of B-type CO 3 group in HA synthetic samples. • The onset temperature of HA densification and dehydroxylation processes correspond. • Calcination of HA influences reactions kinetics with consequences on densification. • Shrinkage of calcined HA sample increases by 10% with respect to uncalcined sample

Thermal and structural characterization of synthetic and natural nanocrystalline hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

Sofronia, Ancuta M. [Ilie Murgulescu Institute of Physical Chemistry of the Romanian Academy, 060021 Bucharest (Romania); Baies, Radu [National Research Institute for Electrochemistry and Condensed Matter, 300224 Timisoara (Romania); Anghel, Elena M. [Ilie Murgulescu Institute of Physical Chemistry of the Romanian Academy, 060021 Bucharest (Romania); Marinescu, Cornelia A., E-mail: alcorina@chimfiz.icf.ro [Ilie Murgulescu Institute of Physical Chemistry of the Romanian Academy, 060021 Bucharest (Romania); Tanasescu, Speranta [Ilie Murgulescu Institute of Physical Chemistry of the Romanian Academy, 060021 Bucharest (Romania)

2014-10-01

The aim of this work was to study the thermal stability on heating and to obtain the processing parameters of synthetic and bone-derived hydroxyapatite over temperatures between room temperature and 1400 °C by thermal analysis (thermogravimetry (TG)/differential scanning calorimetry (DSC) and thermo-mechanical analysis—TMA). Structural and surface modifications related to samples origin and calcination temperature were investigated by Fourier transformed infrared (FTIR) and Raman spectroscopy, X-ray diffraction (XRD) and BET method. FTIR spectra indicated that the organic constituents and carbonate are no longer present in the natural sample calcined at 800 °C. Raman spectra highlighted the decomposition products of the hydroxyapatite. The calcination treatment modifies the processes kinetics of the synthetic samples, being able to isolate lattice water desorption processes of decarbonization and the dehydroxylation processes. Shrinkage of calcined synthetic sample increases by 10% compared to uncalcined synthetic powder. From the TMA correlated with TG analysis and heat capacity data it can be concluded that sintering temperature of the synthetic samples should be chosen in the temperature range of the onset of dehydroxylation and the temperature at which oxyapatite decomposition begins. - Highlights: • Specific surface area of HA powder was reduced from 19.2 to 9.5 m{sup 2}/g by calcination. • Raman spectra indicate the presence of B-type CO{sub 3} group in HA synthetic samples. • The onset temperature of HA densification and dehydroxylation processes correspond. • Calcination of HA influences reactions kinetics with consequences on densification. • Shrinkage of calcined HA sample increases by 10% with respect to uncalcined sample.

Clinical observation of modified hydroxyapatite implant in scleral shell

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Qing-Wei Du

2014-10-01

Full Text Available AIM: To evaluate the clinical effects of modified hydroxyapatite implant in scleral shell.METHODS:Thirty-four cases were performed eye evisceration, autogenous sclera shell anterior and posterior petaloid shape with posterior sclera fenestration, hydroxyapatite artificial eyeballs were implanted at stage I, and conjunctival wound, orbital activity and other complications were observed after surgery.RESULTS: The follow-up was 6～12mo. There was no patients with implant exposure, sclera dissolution, conjunctival wound dehiscence, conjunctival sac constriction noted. All the patients got good activity of artificial globe, and the active range of side motion of the HA was 10°～15°.The artificial eyes looked symmetrical, and the eyes socket were full.CONCLUSION: The modified hydroxyapatite implant in scleral shell can maintain the normal anatomy of the orbital tissue, and also can get full eyes socket and good activity, It was an easy and simple surgery which could obtain satisfactory clinical effect and less complications.

Effect of nano-hydroxyapatite concentration on remineralization of initial enamel lesion in vitro

International Nuclear Information System (INIS)

Huang, S B; Gao, S S; Yu, H Y

2009-01-01

The purpose of the research was to determine the effect of nano-hydroxyapatite concentrations on initial enamel lesions under dynamic pH-cycling conditions. Initial enamel lesions were prepared in bovine enamel with an acidic buffer. NaF (positive control), deionized water (negative control) and four different concentrations of nano-hydroxyapatite (1%, 5%, 10% and 15% wt%) were selected as the treatment agents. Surface microhardness (SMH) measurements were performed before/after demineralization and after 3, 6, 9 and 12 days of application, and the percentage surface microhardness recovery (%SMHR) was calculated. The specimens were then examined by a scanning electron microscope. The %SMHR in nano-hydroxyapatite groups was significantly greater than that of negative control. When the concentration of nano-HA was under 10%, SMH and %SMHR increased with increasing nano-hydroxyapatite concentrations. There were no significant differences between the 10% and 15% groups at different time periods in the pH-cycling. The SEM analysis showed that nano-hydroxyapatite particles were regularly deposited on the cellular structure of the demineralized enamel surface, which appeared to form new surface layers. It was concluded that nano-hydroxyapatite had the potential to remineralize initial enamel lesions. A concentration of 10% nano-hydroxyapatite may be optimal for remineralization of early enamel caries.

Effect of nano-hydroxyapatite concentration on remineralization of initial enamel lesion in vitro

Energy Technology Data Exchange (ETDEWEB)

Huang, S B; Gao, S S; Yu, H Y, E-mail: yhyang6812@scu.edu.c [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China)

2009-06-15

The purpose of the research was to determine the effect of nano-hydroxyapatite concentrations on initial enamel lesions under dynamic pH-cycling conditions. Initial enamel lesions were prepared in bovine enamel with an acidic buffer. NaF (positive control), deionized water (negative control) and four different concentrations of nano-hydroxyapatite (1%, 5%, 10% and 15% wt%) were selected as the treatment agents. Surface microhardness (SMH) measurements were performed before/after demineralization and after 3, 6, 9 and 12 days of application, and the percentage surface microhardness recovery (%SMHR) was calculated. The specimens were then examined by a scanning electron microscope. The %SMHR in nano-hydroxyapatite groups was significantly greater than that of negative control. When the concentration of nano-HA was under 10%, SMH and %SMHR increased with increasing nano-hydroxyapatite concentrations. There were no significant differences between the 10% and 15% groups at different time periods in the pH-cycling. The SEM analysis showed that nano-hydroxyapatite particles were regularly deposited on the cellular structure of the demineralized enamel surface, which appeared to form new surface layers. It was concluded that nano-hydroxyapatite had the potential to remineralize initial enamel lesions. A concentration of 10% nano-hydroxyapatite may be optimal for remineralization of early enamel caries.

The influence of micropore size on the mechanical properties of bulk hydroxyapatite and hydroxyapatite scaffolds.

Science.gov (United States)

Cordell, Jacqueline M; Vogl, Michelle L; Wagoner Johnson, Amy J

2009-10-01

While recognized as a promising bone substitute material, hydroxyapatite (HA) has had limited use in clinical settings because of its inherent brittle behavior. It is well established that macropores ( approximately 100 microm) in a HA implant, or scaffold, are required for bone ingrowth, but recent research has shown that ingrowth is enhanced when scaffolds also contain microporosity. HA is sensitive to synthesis and processing parameters and therefore characterization for specific applications is necessary for transition to the clinic. To that end, the mechanical behavior of bulk microporous HA and HA scaffolds with multi-scale porosity (macropores between rods in the range of 250-350 microm and micropores within the rods with average size of either 5.96 microm or 16.2 microm) was investigated in order to determine how strength and reliability were affected by micropore size (5.96 microm versus 16.2 microm). For the bulk microporous HA, strength increased with decreasing micropore size in both bending (19 MPa to 22 MPa) and compression (71 MPa to 110 MPa). To determine strength reliability, the Weibull moduli for the bulk microporous HA were determined. The Weibull moduli for bending increased (became more reliable) with decreasing pore size (7 to 10) while the Weibull moduli for compression decreased (became less reliable) with decreasing pore size (9 to 6). Furthermore, the elastic properties of the bulk microporous HA (elastic modulus of 30 GPa) and the compressive strengths of the HA scaffolds with multi-scale porosity (8 MPa) did not vary with pore size. The mechanisms responsible for the trends observed were discussed.

Hydroxyapatite/MCM-41 and SBA-15 Nano-Composites: Preparation, Characterization and Applications

Science.gov (United States)

Anunziata, Oscar A.; Martínez, Maria L.; Beltramone, Andrea R.

2009-01-01

Composites of hydroxyapatite (HaP) and highly ordered large pore mesoporous silica molecular sieves such as, Al-SBA-15 and Al-MCM-41 (denoted as SBA-15 and MCM-41, respectively) were developed, characterized by XRD, BET, FTIR, HRTEM and NMR-MAS, and applied to fluoride retention from contaminated water. The proposed procedure by a new route to prepare the HaP/SBA-15 and HaP/MCM-41, composites generates materials with aluminum only in tetrahedral coordination, according to the 27Al NMR-MAS results. Free OH- groups of HaP nanocrystals, within the hosts, allowed high capacity fluoride retention. The activity of fluoride retention using HaP/MCM-41 or HaP/SBA-15 was 1-2 orders of magnitude greater, respectively, than with pure HaP.

Compressive and swelling behavior of cuttlebone derived hydroxyapatite loaded PVA hydrogel implants for articular cartilage

Science.gov (United States)

Kumar, B. Y. Santosh; Kumar, G. C. Mohan; Isloor, Arun M.

2018-04-01

Developing a novel antibacterial, nontoxic and biocompatible hydrogel with superior physio mechanical properties is still becoming a challenge. Herein, we synthesize hydroxyapatite (HA) powder from cuttlefish bone and prepare a series of stiff, tough, high strength, biocompatible hydrogel reinforced with HA by integrating glutaraldehyde into PVA/HA. Powder was characterized by SEM and XRD. Compressive strength and swelling properties are studied and compare the results with the properties of healthy natural articular cartilage.

The Development of Biomimetic Spherical Hydroxyapatite/Polyamide 66 Biocomposites as Bone Repair Materials

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Xuesong Zhang

2014-01-01

Full Text Available A novel biomedical material composed of spherical hydroxyapatite (s-HA and polyamide 66 (PA biocomposite (s-HA/PA was prepared, and its composition, mechanical properties, and cytocompatibility were characterized and evaluated. The results showed that HA distributed uniformly in the s-HA/PA matrix. Strong molecule interactions and chemical bonds were presented between the s-HA and PA in the composites confirmed by IR and XRD. The composite had excellent compressive strength in the range between 95 and 132 MPa, close to that of natural bone. In vitro experiments showed the s-HA/PA composite could improve cell growth, proliferation, and differentiation. Therefore, the developed s-HA/PA composites in this study might be used for tissue engineering and bone repair.

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.

Interaction of human mesenchymal stem cells with osteopontin coated hydroxyapatite surfaces

DEFF Research Database (Denmark)

Jensen, Thomas; Dolatshahi-Pirouz, Alireza; Foss, Morten

2010-01-01

In vitro studies of the initial attachment, spreading and motility of human bone mesenchymal stem cells have been carried out on bovine osteopontin (OPN) coated hydroxyapatite (HA) and gold (Au) model surfaces. The adsorption of OPN extracted from bovine milk was monitored by the quartz crystal...

The synthesis of hydroxyapatite through the precipitation method

International Nuclear Information System (INIS)

Shah Rizal, K.; Fahmi, M.N.; Mat Akil, H.; Zainal Arifin, A.

2004-01-01

Hydroxyapatite (HA) has been earmarked as suitable for implantation within the human body due to the similarity of its chemical makeup to human bone, In this paper, HA powders were synthesized via the precipitation method where phosphoric acid (H 3 PO 4 ) was titrated into calcium hydroxide solution [Ca(OH) 2 ]. Two parameters such as temperature and stirring rate were identified as factors that influenced the amount and purity of HA powder, Phase identification of the synthesized powder was done using X-Ray Diffraction (XRD). The results show that HA phase can be synthesized from this titration process of Ca(OH) 2 and H 3 PO 4 with yield amount of HA powder around 45-61 grams but with less than hundred percent purity. In order to study the effect of heat treatment to RA crystals structure, HA powder was calcined at 850 degree C for 2 hours. Its found that the degree of crystallinity increases after calcination because of lattice expansion when the materials were heated at higher temperature. (Author)

Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

Energy Technology Data Exchange (ETDEWEB)

Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Chathuranga Senarathna, K.G. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Herath, H.M.T.U. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Medical Laboratory Science, Faculty of Allied Health Sciences, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Premachandra, T.N. [Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Ranasinghe, C.S.K. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.P.V.J. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.M.G., E-mail: rmgr@pdn.ac.lk [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Edirisinghe, Mohan; Mahalingam, S. [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Bandara, I.M.C.C.D. [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia); Singh, Sanjleena [Central Analytical Research Facility, Institute of Future Environments, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia)

2016-06-01

Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO{sub 2} thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. - Highlights: • Colloidal hydroxyapatite nanorods are prepared by a novel method. • Surfaces of titanium metal plates are modified by self-forming TiO{sub 2} thin-films. • Prostheses are prepared by coating hydroxyapatite on surface modified Ti metal. • Bioactivity and noncytotoxicity are increased with surface modifications.

Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

International Nuclear Information System (INIS)

Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Chathuranga Senarathna, K.G.; Herath, H.M.T.U.; Premachandra, T.N.; Ranasinghe, C.S.K.; Rajapakse, R.P.V.J.; Rajapakse, R.M.G.; Edirisinghe, Mohan; Mahalingam, S.; Bandara, I.M.C.C.D.; Singh, Sanjleena

2016-01-01

Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO_2 thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. - Highlights: • Colloidal hydroxyapatite nanorods are prepared by a novel method. • Surfaces of titanium metal plates are modified by self-forming TiO_2 thin-films. • Prostheses are prepared by coating hydroxyapatite on surface modified Ti metal. • Bioactivity and noncytotoxicity are increased with surface modifications.

Vascular endothelial growth factor attachment to hydroxyapatite via self-assembled monolayers promotes angiogenic activity of endothelial cells

International Nuclear Information System (INIS)

Solomon, Kimberly D.; Ong, Joo L.

2013-01-01

Currently, tissue engineered constructs for critical sized bone defects are non-vascularized. There are many strategies used in order to promote vascularization, including delivery of growth factors such as vascular endothelial growth factor (VEGF). In this study, hydroxyapatite (HA) was coated with self-assembled monolayers (SAMs). The SAMs were in turn used to covalently bind VEGF to the surface of HA. The different SAM chain length ratios (phosphonoundecanoic acid (11-PUDA):16-phosphonohexadecanoic acid (16-PHDA) utilized in this study were 0:100, 25:75, 50:50, 75:25, and 100:0. Surfaces were characterized by contact angle (CA) and atomic force microscopy, and an in vitro VEGF release study was performed. It was observed that CA and root-mean-squared roughness were not significantly affected by the addition of SAMs, but that CA was significantly lowered with the addition of VEGF. VEGF release profiles of bound VEGF groups all demonstrated less initial burst release than adsorbed control, indicating that VEGF was retained on the HA surface when bound by SAMs. An in vitro study using human aortic endothelial cells (HAECs) demonstrated that bound VEGF increased metabolic activity and caused sustained production of angiopoietin-2, an angiogenic marker, over 28 days. In conclusion, SAMs provide a feasible option for growth factor delivery from HA surfaces, enhancing angiogenic activity of HAECs in vitro. - Highlights: • Vascular endothelial growth factor (VEGF) is attached to hydroxyapatite (HA). • Self-assembled monolayers (SAMs) delay the release of VEGF from hydroxyapatite. • SAM chain length ratio affects the total mass of VEGF released. • VEGF on HA up-regulates proliferation and angiogenic activity of endothelial cells

Effect of n-HA with different surface-modified on the properties of n-HA/PLGA composite

Energy Technology Data Exchange (ETDEWEB)

Jiang Liuyun, E-mail: jlytxg@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Xiong Chengdong; Chen Dongliang [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Jiang Lixin [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Graduated School of Chinese Academy of Sciences, Beijing 100039 (China); Pang Xiubing [Zhejiang Apeloa Medical Technology Co. Ltd, Jinhua 322118 (China)

2012-10-15

Graphical abstract: The bend strength of n-HA/PLGA composite with the unmodified n-HA becomes lower than that of PLGA. However, when n-HA was modified by different methods, the bend strength of g-n-HA/PLGA composites gets a little increase than PLGA, and the g3-n-HA/PLGA shows the highest bend strength at 3% g3-n-HA loading amount in weight, reached 162 MPa, which was 24.4% higher than that of pure PLGA. Highlights: Black-Right-Pointing-Pointer A new surface modification method for n-HA of combining stearic acid with surface-grafting L-lactic was adopted. Black-Right-Pointing-Pointer Three different surface modification methods for n-HA were compared in detail. Black-Right-Pointing-Pointer The new surface modification method was the most ideal method in this study. Black-Right-Pointing-Pointer The g3-n-HA/PLGA composite had the highest bending strength, which would be potential to be used as bone fracture internal fixation materials. - Abstract: Three different surface modification methods for nano-hydroxyapatite (n-HA) of stearic acid, grafted with L-lactide, combining stearic acid and surface-grafting L-lactic were adopted, respectively. The surface modification reaction and the effect of different methods were evaluated by Fourier transformation infrared (FTIR), X-ray photoelectron spectra (XPS), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM). The results showed that n-HA surfaces were all successful modified, and the modification method of combining stearic acid and surface-grafting L-lactic had the greatest grafting amount and the best dispersion among the three modification methods. Then, the n-HA with three different surface modification and unmodified n-HA were introduced into PLGA, respectively, and a serials of n-HA/PLGA composites with 3% n-HA amount in weight were prepared by solution mixing, and the properties of n-HA/PLGA composites were also investigated by electromechanical universal tester and scanning electron

The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants in sheep

DEFF Research Database (Denmark)

Babiker, Hassan

  The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants IN SHEEP   Ph.D. Student, Hassan Babiker; Associate Professor, Ph.D. Ming Ding; Professor, dr.med., Soren Overgaard. Department of Orthopaedic Surgery, Odense University Hospital......, Odense, Denmark   Background: Hydroxyapatite and collagen composites (HA/coll) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effect of newly developed HA/coll-composites with and without bone marrow aspirate (BMA) in order to enhance the fixation...... of bone implants.   Materials and Methods: Titanium alloy implants were inserted into bilateral femoral condyles of 8 skeletally mature sheep, four in each sheep. The implant has a circumferential gap of 2 mm. The gap was filled with: HA/coll; HA/coll-BMA; autograft or allograft. Allograft was served...

Induction of bone formation by smart biphasic hydroxyapatite tricalcium phosphate biomimetic matrices in the non-human primate Papio ursinus

CSIR Research Space (South Africa)

Ripamonti, U

2008-01-01

Full Text Available Long-term studies in the non-human primate Chacma baboon Papio ursinus were set to investigate the induction of bone formation by biphasic hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) biomimetic matrices. HA/β-TCP biomimetic matrices in a pre...

Quantification of carbon nanotube induced adhesion of osteoblast on hydroxyapatite using nano-scratch technique

International Nuclear Information System (INIS)

Lahiri, Debrupa; Agarwal, Arvind; Benaduce, Ana Paula; Kos, Lidia

2011-01-01

This paper explores the nano-scratch technique for measuring the adhesion strength of a single osteoblast cell on a hydroxyapatite (HA) surface reinforced with carbon nanotubes (CNTs). This technique efficiently separates out the contribution of the environment (culture medium and substrate) from the measured adhesion force of the cell, which is a major limitation of the existing techniques. Nano-scratches were performed on plasma sprayed hydroxyapatite (HA) and HA-CNT coatings to quantify the adhesion of the osteoblast. The presence of CNTs in HA coating promotes an increase in the adhesion of osteoblasts. The adhesion force and energy of an osteoblast on a HA-CNT surface are 17 ± 2 μN/cell and 78 ± 14 pJ/cell respectively, as compared to 11 ± 2 μN/cell and 45 ± 10 pJ/cell on a HA surface after 1 day of incubation. The adhesion force and energy of the osteoblasts increase on both the surfaces with culture periods of up to 5 days. This increase is more pronounced for osteoblasts cultured on HA-CNT. Staining of actin filaments revealed a higher spreading and attachment of osteoblasts on a surface containing CNTs. The affinity of CNTs to conjugate with integrin and other proteins is responsible for the enhanced attachment of osteoblasts. Our results suggest that the addition of CNTs to surfaces used in medical applications may be beneficial when stronger adhesion of osteoblasts is desired.

Electrospun Porous PDLLA Fiber Membrane Coated with nHA

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Linhui Qiang

2018-05-01

Full Text Available Porous poly- D, L-lactic acid (PDLLA electrospinning fiber membrane was prepared, and nano-hydroxyapatite (nHA was adsorbed and wrapped into it during the unique shrinking process of the PDLLA fiber membrane to fabricate the PDLLA/nHA composite membrane scaffold for tissue engineering. Compare with the composite fibers prepared by blend electrospinning, most of nHA particles are observed to distribute on the surface of new type composite fibers, which could significantly improve the water wettability and induce the cellular adherence. FTIR analysis indicated that the PDLLA/nHA composite fibrous membrane was formed by physical adsorption. The combination was probed by scanning electron microscope, thermo-gravimetric, water contact angle and mechanical property analysis. It was proved that the nHA particles’ content and distribution, surface wettability, modulus and tensile strength of PDLLA/nHA composite fibrous membrane were influenced by the concentration of nHA dispersion and pores on the PDLLA fiber surface. The 10.6 wt % PDLLA/nHA composite fibrous membrane exhibits a more balanced tensile strength (3.28 MPa and surface wettability (with a water contact angle of 0° of the composite mats. Scanning electron microscope and confocal laser scanning microscopy images of chondrocyte proliferation further showed that the composite scaffold is non-toxic. The adherence and proliferation of chondrocytes on the 10.6 wt % PDLLA/nHA fibrous membrane was significantly improved, compared with PDLLA mat. The 10.6 wt % PDLLA/nHA composite fibrous membrane has potential application value as scaffold material in tissue engineering.

Hydroxyapatite synthesis on solid surfaces using a biological approach

International Nuclear Information System (INIS)

Wang, A; Mei, J; Tse, Y Y; Jones, I P; Sammons, R L

2012-01-01

Many naturally occurring mineralisation processes yield hydroxyapatite (HA) or related salts, but biological routes to calcification have not generally been exploited for production of hydroxyapatite for clinical and industrial applications. Serratia sp. NCIMB 40259 is a non-pathogenic Gram-negative bacterium which is capable of growing as a biofilm on many surfaces and can be used to form HA coatings on a variety of polymeric and metallic materials, including titanium. Here we review previous work and report the results of more recent studies on the influence of titanium compositional and surface properties on Serratia adherence and proliferation and biomineralisation on commercially pure titanium (cp Ti) discs and a Ti mesh. Bacterial adherence was equivalent on cpTi and Ti6Al4V, and biofilms formed on both rough and mirror-polished cpTi surfaces. Embedded alumina particles and alkali treatment did not noticeably alter the precipitation of Serratia HA, nor the structure of the coating in comparison with non-treated substrates. Coatings were retained after sintering at 800°C in argon, although the original curved plate-like crystals changed to nano-scale β-tricalcium phosphate particles. A phosphorous-rich diffusion zone formed at the coating-titanium interface. Bacterial mineralisation may have applications as a method for producing coatings on implants in non load-bearing sites, and non-clinical applications where a high surface area is the major concern.

Hydroxyapatite synthesis on solid surfaces using a biological approach

Science.gov (United States)

Wang, A.; Mei, J.; Tse, Y. Y.; Jones, I. P.; Sammons, R. L.

2012-12-01

Many naturally occurring mineralisation processes yield hydroxyapatite (HA) or related salts, but biological routes to calcification have not generally been exploited for production of hydroxyapatite for clinical and industrial applications. Serratia sp. NCIMB 40259 is a non-pathogenic Gram-negative bacterium which is capable of growing as a biofilm on many surfaces and can be used to form HA coatings on a variety of polymeric and metallic materials, including titanium. Here we review previous work and report the results of more recent studies on the influence of titanium compositional and surface properties on Serratia adherence and proliferation and biomineralisation on commercially pure titanium (cp Ti) discs and a Ti mesh. Bacterial adherence was equivalent on cpTi and Ti6Al4V, and biofilms formed on both rough and mirror-polished cpTi surfaces. Embedded alumina particles and alkali treatment did not noticeably alter the precipitation of Serratia HA, nor the structure of the coating in comparison with non-treated substrates. Coatings were retained after sintering at 800°C in argon, although the original curved plate-like crystals changed to nano-scale β-tricalcium phosphate particles. A phosphorous-rich diffusion zone formed at the coating-titanium interface. Bacterial mineralisation may have applications as a method for producing coatings on implants in non load-bearing sites, and non-clinical applications where a high surface area is the major concern.

Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

Science.gov (United States)

Parcharoen, Yardnapar; Kajitvichyanukul, Puangrat; Sirivisoot, Sirinrath; Termsuksawad, Preecha

2014-08-01

Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO2) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO2 nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH4F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO2 nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO2 nanotubes were found when high viscous electrolyte, NH4F in glycerol, was used. Negative voltage (-4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO2 nanotubes was significantly increased by times. The TiO2 nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO2 nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that growing on titanium plate surface.

Characterization of mechanical properties of hydroxyapatite-silicon-multi walled carbon nano tubes composite coatings synthesized by EPD on NiTi alloys for biomedical application.

Science.gov (United States)

Khalili, Vida; Khalil-Allafi, Jafar; Sengstock, Christina; Motemani, Yahya; Paulsen, Alexander; Frenzel, Jan; Eggeler, Gunther; Köller, Manfred

2016-06-01

Release of Ni(1+) ions from NiTi alloy into tissue environment, biological response on the surface of NiTi and the allergic reaction of atopic people towards Ni are challengeable issues for biomedical application. In this study, composite coatings of hydroxyapatite-silicon multi walled carbon nano-tubes with 20wt% Silicon and 1wt% multi walled carbon nano-tubes of HA were deposited on a NiTi substrate using electrophoretic methods. The SEM images of coated samples exhibit a continuous and compact morphology for hydroxyapatite-silicon and hydroxyapatite-silicon-multi walled carbon nano-tubes coatings. Nano-indentation analysis on different locations of coatings represents the highest elastic modulus (45.8GPa) for HA-Si-MWCNTs which is between the elastic modulus of NiTi substrate (66.5GPa) and bone tissue (≈30GPa). This results in decrease of stress gradient on coating-substrate-bone interfaces during performance. The results of nano-scratch analysis show the highest critical distance of delamination (2.5mm) and normal load before failure (837mN) as well as highest critical contact pressure for hydroxyapatite-silicon-multi walled carbon nano-tubes coating. The cell culture results show that human mesenchymal stem cells are able to adhere and proliferate on the pure hydroxyapatite and composite coatings. The presence of both silicon and multi walled carbon nano-tubes (CS3) in the hydroxyapatite coating induce more adherence of viable human mesenchymal stem cells in contrast to the HA coated samples with only silicon (CS2). These results make hydroxyapatite-silicon-multi walled carbon nano-tubes a promising composite coating for future bone implant application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chondroitin sulfate template-mediated biomimetic synthesis of nano-flake hydroxyapatite

Science.gov (United States)

He, Dan; Xiao, Xiufeng; Liu, Fang; Liu, Rongfang

2008-11-01

By Ca(NO 3) 2·4H 2O and (NH 4) 3PO 4·3H 2O as reagents and chondroitin sulfate (ChS) as a template, nano-flake hydroxyapatite (HA) is synthesized using a biomimetic method according to the biomineralization theory. HA crystals obtained are characterized in crystalline phase, microstructure, chemical composition and morphology by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscopy (TEM) and elemental analysis respectively. UV-vis spectrum is adopted to investigate interactions between functional groups ChS and HA. The results show that HA crystal nucleation and growth take place in chemical interactions between HA crystals and ChS as a template. And elemental analysis indicates that obtained HA contains a small amount of ChS. Furthermore, ChS concentration significantly affects the morphology of HA crystals. Staple-fiber-like HA crystals can be obtained at a low concentration in ChS, and flake-like HA crystals synthesized at a high concentration (≥0.5 wt.%) of ChS as a template.

Chondroitin sulfate template-mediated biomimetic synthesis of nano-flake hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

He Dan; Xiao Xiufeng; Liu Fang [College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007 (China); Liu Rongfang [College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007 (China)], E-mail: rfliu@vip.sina.com

2008-11-15

By Ca(NO{sub 3}){sub 2}.4H{sub 2}O and (NH{sub 4}){sub 3}PO{sub 4}.3H{sub 2}O as reagents and chondroitin sulfate (ChS) as a template, nano-flake hydroxyapatite (HA) is synthesized using a biomimetic method according to the biomineralization theory. HA crystals obtained are characterized in crystalline phase, microstructure, chemical composition and morphology by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscopy (TEM) and elemental analysis respectively. UV-vis spectrum is adopted to investigate interactions between functional groups ChS and HA. The results show that HA crystal nucleation and growth take place in chemical interactions between HA crystals and ChS as a template. And elemental analysis indicates that obtained HA contains a small amount of ChS. Furthermore, ChS concentration significantly affects the morphology of HA crystals. Staple-fiber-like HA crystals can be obtained at a low concentration in ChS, and flake-like HA crystals synthesized at a high concentration ({>=}0.5 wt.%) of ChS as a template.

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.

A Study of Hybrid Composite Hydroxyapatite (HA-Geopolymers as a Material for Biomedical Application

Directory of Open Access Journals (Sweden)

Saleha

2017-01-01

Full Text Available The main purpose of this research is to study the physical properties and microstructure characters of hybrid composites HA-geopolymers as a material for biomedical application. Hybrid composite HA–geopolymers were produced through alkaline activation method of metakaolin as a matrix and HA as the filler. HA was synthesized from eggshell particles by using a precipitation method. The addition of HA in metakaolin paste was varied from 0.5%, 1.0%, 1.5%, and 2.0% relative the weight of metakaolin. FTIR was used to examine the absorption bands the composites. X-ray diffraction (XRD was used to study the crystal structure of the starting and the resulting materials. Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS was used to investigate the surface morphology of the composites. The thermal properties of the samples was examined by means of Differential Scanning Calorimetry (DSC. Capacitance measurement was conducted to investigate the bioactive properties of HA. The study results suggest that hybrid composite HA-geopolymers has a potential to be applied as a biomedical such as biosensor material.

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.

Does hydroxyapatite coating enhance ingrowth and improve longevity of a Zweymuller type stem? A double-blinded randomised RSA trial.

Science.gov (United States)

Hoornenborg, Daniel; Sierevelt, Inger N; Spuijbroek, Joost A; Cheung, John; van der Vis, Harm M; Beimers, Lijkele; Haverkamp, Daniel

2017-09-11

An ongoing discussion is whether using a hydroxyapatite coating enhances the ingrowth and longevity of a femoral stem in total hip arthroplasty. The best way to predict speed of ingrowth and long-term outcome is by evaluating micromotion by radiostereometric analysis. To study the effect of hydroxyapatite (HA) coating on the migration of the SL-PLUS hip stem, we performed a prospective double blind randomised controlled trial comparing the early migration of the hydroxyapatite (HA)-coated SL-PLUS stem compared to the Standard (non-coated) SL-PLUS stem. 51 patients were randomly assigned to receive either an uncoated or a HA-coated femoral component during total hip replacement. RSA images were obtained direct postoperatively and at 6 weeks, 12 weeks, 6 months, 12 months and 24 months. HOOS scores were obtained preoperative and at final follow-up. RSA evaluation demonstrated significant migration up to 3 months postoperatively in both groups. After initial setting no significant migration was observed. There was no significant difference in migration between the HA-coated group and the uncoated group.Both Harris Hip Score (HHS) and HOOS domain scores (pain and ADL) significantly improved compared to baseline at 24 months after surgery in both treatment groups (p<0.001 for all comparisons). Improvement did not differ significantly between the 2 groups. At 2 years follow-up, the HA-coated and uncoated Zweymuller type, distal fitting stem do not show different migration patterns.

Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair

Science.gov (United States)

CALASANS-MAIA, Mônica Diuana; de MELO, Bruno Raposo; ALVES, Adriana Terezinha Neves Novellino; RESENDE, Rodrigo Figueiredo de Brito; LOURO, Rafael Seabra; SARTORETTO, Suelen Cristina; GRANJEIRO, José Mauro; ALVES, Gutemberg Gomes

2015-01-01

ABSTRACT Objective The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA). Material and Methods The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. Results The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day. Conclusion CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption. PMID:26814461

Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair

Directory of Open Access Journals (Sweden)

Mônica Diuana CALASANS-MAIA

2015-12-01

Full Text Available ABSTRACT Objective The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA. Material and Methods The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group (n=5/period/group. After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. Results The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05 indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day. Conclusion CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption.

Biomimetic composite microspheres of collagen/chitosan/nano-hydroxyapatite: In-situ synthesis and characterization.

Science.gov (United States)

Teng, Shu-Hua; Liang, Mian-Hui; Wang, Peng; Luo, Yong

2016-01-01

The collagen/chitosan/hydroxyapatite (COL/CS/HA) composite microspheres with a good spherical form and a high dispersity were successfully obtained using an in-situ synthesis method. The FT-IR and XRD results revealed that the inorganic phase in the microspheres was crystalline HA containing carbonate ions. The morphology of the composite microspheres was dependent on the HA content, and a more desirable morphology was achieved when 20 wt.% HA was contained. The composite microspheres exhibited a narrow particle distribution, most of which ranged from 5 to 10 μm. In addition, the needle-like HA nano-particles were uniformly distributed in the composite microspheres, and their crystallinity and crystal size decreased with the HA content. Copyright © 2015 Elsevier B.V. All rights reserved.

The Production of Porous Hydroxyapatite Scaffolds with Graded Porosity by Sequential Freeze-Casting.

Science.gov (United States)

Lee, Hyun; Jang, Tae-Sik; Song, Juha; Kim, Hyoun-Ee; Jung, Hyun-Do

2017-03-31

Porous hydroxyapatite (HA) scaffolds with porosity-graded structures were fabricated by sequential freeze-casting. The pore structures, compressive strengths, and biocompatibilities of the fabricated porous HA scaffolds were evaluated. The porosities of the inner and outer layers of the graded HA scaffolds were controlled by adjusting the initial HA contents of the casting slurries. The interface between the dense and porous parts was compact and tightly adherent. The porosity and compressive strengths of the scaffold were controlled by the relative thicknesses of the dense/porous parts. In addition, the porous HA scaffolds showed good biocompatibility in terms of preosteoblast cell attachment and proliferation. The results suggest that porous HA scaffolds with load-bearing parts have potential as bone grafts in hard-tissue engineering.

Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep

DEFF Research Database (Denmark)

Ding, Ming; Andreasen, Christina Møller; Dencker, Mads L.

2015-01-01

hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could...

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.

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.

Surface modified nano-hydroxyapatite/poly(lactide acid) composite and its osteocyte compatibility

International Nuclear Information System (INIS)

Diao Huaxin; Si Yunfeng; Zhu Aiping; Ji Lijun; Shi Hongchan

2012-01-01

In this study, melt blending was used to fabricate poly(lactic acid) (PLA)/ hydroxyapatite (HA) nanocomposites. Surface modifying HA nanoparticles (mHA) with dodecyl alcohol through esterification reaction could effectively improve the dispersibility of HA nanoparticles in PLA matrix and the interfacial interactions between PLA and HA nanoparticles, as revealed by field emission scanning electron microscopy (FESEM), rheology analysis, and dynamic mechanical thermal analysis (DMTA). mHA/PLA nanocomposite film demonstrated better cartilage cell attachment, spreading and proliferation than that of PLA and HA/PLA film. The good cytocompatibility could be due to the good dispersibility of the osteoinductive HA nanoparticles, good interfacial interactions between PLA and HA nanoparticles, and balanced hydrophobic/hydrophilic property. This newly developed mHA/PLA nanocomposites may be considered for bone tissue engineering applications. - Highlights: ► Dodecyl alcohol modifies HA nanoparticles via esterification reaction. ► The modified HA results in good dispersibility in PLA matrix. ► The interfacial interactions are improved because of the modified HA. ► The addition of HA and mHA results in good cell affinity and biocompatibility.

Polymer-Assisted Hydrothermal Synthesis of Hierarchically Arranged Hydroxyapatite Nanoceramic

Directory of Open Access Journals (Sweden)

A. Joseph Nathanael

2013-01-01

Full Text Available Flower-like hydroxyapatite (HA nanostructures were synthesized by a polymer-assisted hydrothermal method. The thickness of the petals/plates decreased from 200 nm to 40 nm as the polymer concentration increased. The thickness also decreased as the hydrothermal treatment time increased from 6 to 12 hr. The HRTEM and SAED patterns suggest that the floral-like HA nanostructures are single crystalline in nature. Structural analysis based on XRD and Raman experiments implied that the produced nanostructure is a pure form of HA without any other impurities. The possible formation mechanism was discussed for the formation of flower-like HA nanostructures during polymer-assisted hydrothermal synthesis. Finally, in vitro cellular analysis revealed that the hierarchically arranged HA nanoceramic had improved cell viability relative to other structures. The cells were actively proliferated over these nanostructures due to lower cytotoxicity. Overall, the size and the crystallinity of the nanostructures played a role in improving the cell proliferation.

Poly(vinyl alcohol) hydrogel coatings with tunable surface exposure of hydroxyapatite

Science.gov (United States)

Moreau, David; Villain, Arthur; Ku, David N; Corté, Laurent

2014-01-01

Insufficient bone anchoring is a major limitation of artificial substitutes for connective osteoarticular tissues. The use of coatings containing osseoconductive ceramic particles is one of the actively explored strategies to improve osseointegration and strengthen the bone-implant interface for general tissue engineering. Our hypothesis is that hydroxyapatite (HA) particles can be coated robustly on specific assemblies of PVA hydrogel fibers for the potential anchoring of ligament replacements. A simple dip-coating method is described to produce composite coatings made of microscopic hydroxyapatite (HA) particles dispersed in a poly(vinyl alcohol) (PVA) matrix. The materials are compatible with the requirements for implant Good Manufacturing Practices. They are applied to coat bundles of PVA hydrogel fibers used for the development of ligament implants. By means of optical and electronic microscopy, we show that the coating thickness and surface state can be adjusted by varying the composition of the dipping solution. Quantitative analysis based on backscattered electron microscopy show that the exposure of HA at the coating surface can be tuned from 0 to over 55% by decreasing the weight ratio of PVA over HA from 0.4 to 0.1. Abrasion experiments simulating bone-implant contact illustrate how the coating cohesion and wear resistance increase by increasing the content of PVA relative to HA. Using pullout experiments, we find that these coatings adhere well to the fiber bundles and detach by propagation of a crack inside the coating. These results provide a guide to select coated implants for anchoring artificial ligaments. PMID:25482413

Poly(vinyl alcohol) hydrogel coatings with tunable surface exposure of hydroxyapatite.

Science.gov (United States)

Moreau, David; Villain, Arthur; Ku, David N; Corté, Laurent

2014-01-01

Insufficient bone anchoring is a major limitation of artificial substitutes for connective osteoarticular tissues. The use of coatings containing osseoconductive ceramic particles is one of the actively explored strategies to improve osseointegration and strengthen the bone-implant interface for general tissue engineering. Our hypothesis is that hydroxyapatite (HA) particles can be coated robustly on specific assemblies of PVA hydrogel fibers for the potential anchoring of ligament replacements. A simple dip-coating method is described to produce composite coatings made of microscopic hydroxyapatite (HA) particles dispersed in a poly(vinyl alcohol) (PVA) matrix. The materials are compatible with the requirements for implant Good Manufacturing Practices. They are applied to coat bundles of PVA hydrogel fibers used for the development of ligament implants. By means of optical and electronic microscopy, we show that the coating thickness and surface state can be adjusted by varying the composition of the dipping solution. Quantitative analysis based on backscattered electron microscopy show that the exposure of HA at the coating surface can be tuned from 0 to over 55% by decreasing the weight ratio of PVA over HA from 0.4 to 0.1. Abrasion experiments simulating bone-implant contact illustrate how the coating cohesion and wear resistance increase by increasing the content of PVA relative to HA. Using pullout experiments, we find that these coatings adhere well to the fiber bundles and detach by propagation of a crack inside the coating. These results provide a guide to select coated implants for anchoring artificial ligaments.

Designing, preparing and evaluation of novel HA/Ti composite coating for endodontic dental implant

Directory of Open Access Journals (Sweden)

Fathi MH.

2002-08-01

Full Text Available Nowadays, application of implants as a new method for replacing extracted teeth have been improved. So, many researches have been performed for improving the characteristics of implants. The aim of this study was to design and produce a desired coating in order to obtaining two goals including; improvement of the corrosion behavior of metallic endodontic implant and the bone osseointegration simultaneously. Stainless steel 316L (SS, cobalt-chromium alloy (Vit and commercial pure titanium (cpTi were chosen as metallic substrates and hydroxyapatite coating (HAC were performed by plasma-spraying (PS process on three different substrates. A novel double layer Hydroxyapatite/Titanium (HA/Ti composite coating composed of a HA top layer and a Ti under layer was prepared using PS and physical vapor deposition (PVD process respectively on SS. Structural characterization techniques including XRD, SEM and EDX were utilized to investigate the microstructure, morpholgy and crystallinity of the coatings. Electrochemical potentiodynamic tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens behavior as an indication of biocmpatibility. Results indicated that the cpTi possesses the highest and SS the lowest corrosion resistance (highest corrosion current density between uncoated substrates. This trend was independent to the type of physiological environment. The HA coating decreased the corrosion current density of HA coated metallic implants but did not change that trend. HAC acted as a mechanical barrier on the metallic substrate but could not prevent the interaction between metallic substrate and environment completely. The HA/Ti composite coating improved the corrosion behavior of SS. The corrosion current density of HA/Ti coated SS decreased and was exactly similar to single HA coated cpTi in physiological solutions. The results indicated that HA/Ti composite coated SS

Synthesis and chemical and structural characterization of hydroxyapatite obtained from eggshell and tricalcium phosphate

OpenAIRE

Arboleda, Alejandro; Franco, Manuel; Caicedo, Julio; Tirado, Liliana; Goyes, Clara

2016-01-01

The eggshell is a common residue that is usually discarded without giving any use to it. In this paper the results obtained from a proposed procedure to get hydroxyapatite (HA) from eggshell are shown. The HA is a calcium phosphate which has been widely used as implant material due to the close similarity of its composition with the inorganic phase of natural bone. HA generally has a high cost and it is presented as micro and nanostructured bioceramics; the last one is a promising option for ...

Biocompatibility and Biocorrosion of Hydroxyapatite-Coated Magnesium Plate: Animal Experiment

Directory of Open Access Journals (Sweden)

Ho-Kyung Lim

2017-09-01

Full Text Available Magnesium (Mg has the advantage of being resorbed in vivo, but its resorption rate is difficult to control. With uncontrolled resorption, Magnesium as a bone fixation material has minimal clinical value. During resorption not only is the strength rapidly weakened, but rapid formation of metabolite also occurs. In order to overcome these disadvantages, hydroxyapatite (HA surface coating of pure magnesium plate was attempted in this study. Magnesium plates were inserted above the frontal bone of Sprague-Dawley rats in both the control group (Bare-Mg group and the experimental group (HA-Mg group. The presence of inflammation, infection, hydrogen gas formation, wound dehiscence, and/or plate exposure was observed, blood tests were performed, and the resorption rate and tensile strength of the retrieved metal plates were measured. The HA-Mg group showed no gas formation or plate exposure until week 12. However, the Bare-Mg group showed consistent gas formation and plate exposure beginning in week 2. WBC (White Blood Cell, BUN (Blood Urea Nitrogen, Creatinine, and serum magnesium concentration levels were within normal range in both groups. AST (Aspartate Aminotransferase and ALT (Alanine Aminotransferase values, however, were above normal range in some animals of both groups. The HA-Mg group showed statistically significant advantage in resistance to degradation compared to the Bare-Mg group in weeks 2, 4, 6, 8, and 12. Degradation of HA-Mg plates proceeded after week 12. Coating magnesium plates with hydroxyapatite may be a viable method to maintain their strength long enough to allow bony healing and to control the resorption rate during the initial period.

Study the properties of dense hydroxyapatite-extract from cow bone

International Nuclear Information System (INIS)

Sri Asliza, M.A.; Zaheruddin, K.; Shahrizal, H.

2009-01-01

In this study, natural hydroxyapatite (HA) was extracted from clean cow bone by treatment with NaOH and heating at high temperature before ground into fine powder. The HA powder were than mixed together with binder for several hours. Dense HA were formed in die steel mould by using uniaxially pressing method. Sample was sintered at different temperature 1150, 1200, 1250 and 1300 degree Celsius for several hours. The phases of specimen were identified using X-ray diffraction (XRD). The mechanical properties were analyzed using three-point bending testing and the microstructure was observed by scanning electron microscopy. From XRD results, natural HA shows phase of pure HA up to 1250 degree Celsius and fracture strength results indicated that the mechanical properties of specimen increase as temperature increase. From microstructure observation using SEM, HA specimen shows initial stages of sintering process at temperature 1150 degree Celsius and show changes in microstructure evolution as temperature increase up to 1300 degree Celsius. (author)

Surface microstructure and cell biocompatibility of silicon-substituted hydroxyapatite coating on titanium substrate prepared by a biomimetic process

International Nuclear Information System (INIS)

Zhang Erlin; Zou Chunming; Yu Guoning

2009-01-01

Silicon-substituted hydroxyapatite (Si-HA) coatings with 0.14 to 1.14 at.% Si on pure titanium were prepared by a biomimetic process. The microstructure characterization and the cell compatibility of the Si-HA coatings were studied in comparison with that of hydroxyapatite (HA) coating prepared in the same way. The prepared Si-HA coatings and HA coating were only partially crystallized or in nano-scaled crystals. The introduction of Si element in HA significantly reduced P and Ca content, but densified the coating. The atom ratio of Ca to (P + Si) in the Si-HA coatings was in a range of 1.61-1.73, increasing slightly with an increase in the Si content. FTIR results displayed that Si entered HA in a form of SiO 4 unit by substituting for PO 4 unit. The cell attachment test showed that the HA and Si-HA coatings exhibited better cell response than the uncoated titanium, but no difference was observed in the cell response between the HA coating and the Si-HA coatings. Both the HA coating and the Si-HA coatings demonstrated a significantly higher cell growth rate than the uncoated pure titanium (p < 0.05) in all incubation periods while the Si-HA coating exhibited a significantly higher cell growth rate than the HA coating (p < 0.05). Si-HA with 0.42 at.% Si presented the best cell biocompatibility in all of the incubation periods. It was suggested that the synthesis mode of HA and Si-HA coatings in a simulated body environment in the biomimetic process contribute significantly to good cell biocompatibility

Hierarchically nanostructured hydroxyapatite: hydrothermal synthesis, morphology control, growth mechanism, and biological activity

Science.gov (United States)

Ma, Ming-Guo

2012-01-01

Hierarchically nanosized hydroxyapatite (HA) with flower-like structure assembled from nanosheets consisting of nanorod building blocks was successfully synthesized by using CaCl2, NaH2PO4, and potassium sodium tartrate via a hydrothermal method at 200°C for 24 hours. The effects of heating time and heating temperature on the products were investigated. As a chelating ligand and template molecule, the potassium sodium tartrate plays a key role in the formation of hierarchically nanostructured HA. On the basis of experimental results, a possible mechanism based on soft-template and self-assembly was proposed for the formation and growth of the hierarchically nanostructured HA. Cytotoxicity experiments indicated that the hierarchically nanostructured HA had good biocompatibility. It was shown by in-vitro experiments that mesenchymal stem cells could attach to the hierarchically nanostructured HA after being cultured for 48 hours. Objective The purpose of this study was to develop facile and effective methods for the synthesis of novel hydroxyapatite (HA) with hierarchical nanostructures assembled from independent and discrete nanobuilding blocks. Methods A simple hydrothermal approach was applied to synthesize HA by using CaCl2, NaH2PO4, and potassium sodium tartrate at 200°C for 24 hours. The cell cytotoxicity of the hierarchically nanostructured HA was tested by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Results HA displayed the flower-like structure assembled from nanosheets consisting of nanorod building blocks. The potassium sodium tartrate was used as a chelating ligand, inducing the formation and self-assembly of HA nanorods. The heating time and heating temperature influenced the aggregation and morphology of HA. The cell viability did not decrease with the increasing concentration of hierarchically nanostructured HA added. Conclusion A novel, simple and reliable hydrothermal route had been developed for the synthesis of

Porous hydroxyapatite composite with alumina for bone repair

International Nuclear Information System (INIS)

Rusnah Mustaffa; Mohd Reusmaazran Mohd Yusof; Idris Besar

2010-01-01

Porous fabrications, a number of techniques were investigated using polyurethane foam as the scaffold. These techniques involve dipping of the foam into a slurry prepared by mixing of HA+Al 2 O 3 powder with PVA and Sago as binder and subjecting to burn off procedure to get the porous products. Sintering parameter was studied at 1100, 1200 and 1300 degree Celsius. Initially HA powder was prepared by the sol-gel precipitation method using calcium hydroxide and ortho-phosphoric acid meanwhile Al 2 O 3 powder from supplier (MERK). The fine HA powder, measuring 2 O 3 . These techniques also produce the uniformity pore shape. Characterization of the physical analysis, porosity, surface morphology by Scanning Electron Microscopy analysis (SEM) and compression strength were studied. Mechanical properties showing that the composite of porous HA+Al 2 O 3 gives higher maximum compression strength compared to the porous hydroxyapatite itself. Observation from this studied the increasing of temperature will increase the strength. (author)

Quantification of iodine in porous hydroxyapatite matrices for application as radioactive sources in brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Lacerda, Kassio Andre; Lameiras, Fernando Soares [Centro de Desenvolvimento da Tecnologia Nuclear, (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Viviane Viana [Centro de Desenvolvimento da Tecnologia Nuclear, (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Universidade Vale do Rio Verde de Tres Coracoes, MG (Brazil)

2007-07-15

In this study, non-radioactive iodine was incorporated in two types of biodegradable hydroxyapatite-based porous matrices (HA and HACL) through impregnation process from sodium iodine aqueous solutions with varying concentrations (0.5 and 1.0 mol/L) . The results revealed that both systems presented a high capacity of incorporating iodine into their matrices. The quantity of incorporated iodine was measured through Neutron Activation Analysis (NAA). The porous ceramic matrices based on hydroxyapatite demonstrated a great potential for uses in low dose rate (LDR) brachytherapy. (author)

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.

Preparation and cellular response of porous A-type carbonated hydroxyapatite nanoceramics

Energy Technology Data Exchange (ETDEWEB)

Li Bo, E-mail: Leewave@126.com [Institute of Biomaterials and Living Cell Imaging Technology, School of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing 401331 (China) and National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China); Liao Xiaoling [Institute of Biomaterials and Living Cell Imaging Technology, School of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing 401331 (China); Zheng Li [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China); He Huawei [Department of Prosthodontics, Beijing Stomatological Hospital, Capital Medical University, Beijing, 100050 (China); Wang Hong [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China); Fan Hongsong, E-mail: hsfan68@hotmail.com [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China); Zhang Xingdong [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China)

2012-05-01

Microwave sintering using the activated carbon as embedding material was applied in preparation of porous A-type carbonated hydroxyapatite ceramics with nano(nCHA) and submicron (mCHA) structure. By examining the linear shrinkages and the compressive strengths of samples at different temperatures, a suitable microwave sintering temperature was achieved. The microwave sintering method was successfully used to prepare A-type CHA with nano or submicron structure, and the mechanism of the formation of A-type carbonate groups was discussed also. Compared with the samples prepared by the conventional sintering method (mHA), the nCHA bioceramics synthesized by the microwave sintering approach had smaller grain size and more uniform microstructure, and showed a compressive strength similar to the conventional samples. In vitro dissolution test proved that nCHA exhibits better degradation property in comparison to pure HA. Rat osteoblasts were cultured with nCHA, mCHA and mHA to evaluate their biocompatibility, and nCHA showed significant enhancement of cells in attachment, proliferation and differentiation. In conclusion, carbonate groups can be easily introduced to HA crystal structure using the activated carbon as embedding material, and microwave sintering is an effective and simple method in preparing A-type CHA with a nanostructure. Results from this in vitro biological study suggest that porous A-type carbonated hydroxyapatite nanoceramics may be a much better candidate for clinical use in terms of bioactivity. - Highlights: Black-Right-Pointing-Pointer We prepared porous A-type carbonated hydroxyapatite nanoceramics with microwave sintering. Black-Right-Pointing-Pointer We examined physico-chemical characterization and osteoblast response. Black-Right-Pointing-Pointer The nanoceramics have a comparable compressive strength to samples with conventional sintering method. Black-Right-Pointing-Pointer The nanoceramics enhance degradation property, osteoblast

Effect of membranes and porous hydroxyapatite on healing in bone defects around titanium dental implants. An experimental study in monkeys

DEFF Research Database (Denmark)

Gotfredsen, K; Warrer, K; Hjørting-Hansen

1991-01-01

The purpose of the present study was to examine the effect of treating bony craters around titanium dental implant with polytetrafluoroethylene membranes (PTFE), with and without grafting of hydroxyapatite (HA), and with HA alone. 4 standardized bone defects were prepared in the alveolar ridge...

Additive manufactured Ti6Al4V scaffolds with the RF- magnetron sputter deposited hydroxyapatite coating

International Nuclear Information System (INIS)

Chudinova, E; Surmeneva, M; Surmenev, R; Koptioug, A; Scoglund, P

2016-01-01

Present paper reports on the results of surface modification of the additively manufactured porous Ti6Al4V scaffolds. Radio frequency (RF) magnetron sputtering was used to modify the surface of the alloy via deposition of the biocompatible hydroxyapatite (HA) coating. The surface morphology, chemical and phase composition of the HA-coated alloy were studied. It was revealed that RF magnetron sputtering allows preparing a homogeneous HA coating onto the entire surface of scaffolds. (paper)

Tensile behaviour and properties of a bone analogue composite (HA, HDPE) crosslinked by gamma radiation

International Nuclear Information System (INIS)

Romero, G.; Smolko, Eduardo E.

2005-01-01

A natural composite material, hydroxyapatite (HA) and high density polyethylene (HDPE) crosslinked by ionizing radiations is been developed as a bioactive analogue material for bone replacement. Mechanical properties of the composites irradiated up to 300 kGy under tensile tests was studied. Gel content and micrographs of different composite fractures are shown. (author)

ALP gene expression in cDNA samples from bone tissue engineering using a HA/TCP/Chitosan scaffold

Science.gov (United States)

Stephanie, N.; Katarina, H.; Amir, L. R.; Gunawan, H. A.

2017-08-01

This study examined the potential use of hydroxyapatite (HA)/tricalcium phosphate (TCP)/Chitosan as a bone tissue engineering scaffold. The potential for using HA/TCP/chitosan as a scaffold was analyzed by measuring expression of the ALP osteogenic gene in cDNA from bone biopsies from four Macaque nemestrina. Experimental conditions included control (untreated), treatment with HA/TCP 70:30, HA/TCP 50:50, and HA/TCP/chitosan. cDNA samples were measured quantitively with Real-Time PCR (qPCR) and semi-quantitively by gel electrophoresis. There were no significant differences in ALP gene expression between treatment subjects after two weeks, but the HA/TCP/chitosan treatment gave the highest level of expression after four weeks. The scaffold using the HA/TCP/chitosan combination induced a higher level of expression of the osteogenic gene ALP than did scaffold without chitosan.

Hydroxyapatite implants with designed internal architecture.

Science.gov (United States)

Chu, T M; Halloran, J W; Hollister, S J; Feinberg, S E

2001-06-01

Porous hydroxyapatite (HA) has been used as a bone graft material in the clinics for decades. Traditionally, the pores in these HAs are either obtained from the coralline exoskeletal patterns or from the embedded organic particles in the starting HA powder. Both processes offer very limited control on the pore structure. A new method for manufacturing porous HA with designed pore channels has been developed. This method is essentially a lost-mold technique with negative molds made with Stereolithography and a highly loaded curable HA suspension as the ceramic carrier. Implants with designed channels and connection patterns were first generated from a Computer-Aided-Design (CAD) software and Computer Tomography (CT) data. The negative images of the designs were used to build the molds on a stereolithography apparatus with epoxy resins. A 40 vol% HA suspension in propoxylated neopentyl glycol diacrylate (PNPGDA) and iso-bornyl acrylate (IBA) was formulated. HA suspension was cast into the epoxy molds and cured into solid at 85 degrees C. The molds and acrylate binders were removed by pyrolysis, followed by HA green body sintering. With this method, implants with six different channel designs were built successfully and the designed channels were reproduced in the sintered HA implants. The channels created in the sintered HA implants were between 366 microm and 968 microm in diameter with standard deviations of 50 microm or less. The porosity created by the channels were between 26% and 52%. The results show that HA implants with designed connection pattern and well controlled channel size can be built with the technique developed in this study. Copyright 2001 Kluwer Academic Publishers

Hardystonite improves biocompatibility and strength of electrospun polycaprolactone nanofibers over hydroxyapatite: A comparative study

Energy Technology Data Exchange (ETDEWEB)

Jaiswal, Amit K. [Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 (India); Chhabra, Hemlata; Kadam, Sachin S. [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 (India); Londhe, Kishore; Soni, Vivek P. [Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 (India); Bellare, Jayesh R., E-mail: jb@iitb.ac.in [Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 (India)

2013-07-01

The aim of this study was to compare physico-chemical and biological properties of hydroxyapatite (HA) and hardystonite (HS) based composite scaffolds. Hardystonite (Ca{sub 2}ZnSi{sub 2}O{sub 7}) powders were synthesized by a sol–gel method while polycaprolactone–hardystonite (PCL–HS) and polycaprolactone–hydroxyapatite (PCL–HA) were fabricated in nanofibrous form by electrospinning. The physico-chemical and biological properties such as tensile strength, cell proliferation, cell infiltration and alkaline phosphatase activity were determined on both kinds of scaffolds. We found that PCL–HS scaffolds had better mechanical strength compared to PCL–HA scaffolds. Addition of HA and HS particles to PCL did not show any inhibitory effect on blood biocompatibility of scaffolds when assessed by hemolysis assay. The in vitro cellular behavior was evaluated by growing murine adipose-tissue-derived stem cells (mE-ASCs) over the scaffolds. Enhanced cell proliferation and improved cellular infiltrations on PCL–HS scaffolds were observed when compared to HA containing scaffolds. PCL–HS scaffolds exhibited a significant increase in alkaline phosphatase (ALP) activity and better mineralization of the matrix in comparison to PCL–HA scaffolds. These results clearly demonstrate the stimulatory role of Zn and Si present in HS based composite scaffolds, suggesting their potential application for bone tissue engineering. - Highlights: • The osteogenic potential of PCL–HA and PCL–HS scaffolds was compared. • PCL–HS scaffolds showed better mechanical strength as compared to PCL–HA scaffolds. • Enhanced cell proliferation and infiltration were observed on PCL–HS scaffolds. • mE-ASCs showed better ALP activity and matrix mineralization on PCL–HS scaffolds.

Sol-Gel Derived Hydroxyapatite Coating on Mg-3Zn Alloy for Orthopedic Application

Science.gov (United States)

Singh, Sanjay; Manoj Kumar, R.; Kuntal, Kishor Kumar; Gupta, Pallavi; Das, Snehashish; Jayaganthan, R.; Roy, Partha; Lahiri, Debrupa

2015-04-01

In recent years, magnesium and its alloys have gained a lot of interest as orthopedic implant constituents because their biodegradability and mechanical properties are closer to that of human bone. However, one major concern with Mg in orthopedics is its high corrosion rate that results in the reduction of mechanical integrity before healing the bone tissue. The current study evaluates the sol-gel-derived hydroxyapatite (HA) coating on a selected Mg alloy (Mg-3Zn) for decreasing the corrosion rate and increasing the bioactivity of the Mg surface. The mechanical integrity of the coating is established as a function of the surface roughness of the substrate and the sintering temperature of the coating. Coating on a substrate roughness of 15-20 nm and sintering at 400°C shows the mechanical properties in similar range of bone, thus making it suitable to avoid the stress-shielding effect. The hydroxyapatite coating on the Mg alloy surface also increases corrosion resistance very significantly by 40 times. Bone cells are also found proliferating better in the HA-coated surface. All these benefits together establish the candidature of sol-gel HA-coated Mg-3Zn alloy in orthopedic application.

Properties of natural and synthetic hydroxyapatite and their surface free energy determined by the thin-layer wicking method

Science.gov (United States)

Szcześ, Aleksandra; Yan, Yingdi; Chibowski, Emil; Hołysz, Lucyna; Banach, Marcin

2018-03-01

Surface free energy is one of the parameters accompanying interfacial phenomena, occurring also in the biological systems. In this study the thin layer wicking method was used to determine surface free energy and its components for synthetic hydroxyapatite (HA) and natural one obtained from pig bones. The Raman, FTIR and X-Ray photoelectron spectroscopy, X-ray diffraction techniques and thermal analysis showed that both samples consist of carbonated hydroxyapatite without any organic components. Surface free energy and its apolar and polar components were found to be similar for both investigated samples and equalled γSTOT = 52.4 mJ/m2, γSLW = 40.2 mJ/m2 and γSAB = 12.3 mJ/m2 for the synthetic HA and γSTOT = 54.6 mJ/m2, γSLW = 40.3 mJ/m2 and γSAB = 14.3 mJ/m2 for the natural one. Both HA samples had different electron acceptor (γs+) and electron donor (γs-) parameters. The higher value of the electron acceptor was found for the natural HA whereas the electron donor one was higher for the synthetic HA

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)

Hydroxyapatite from fish scale for potential use as bone scaffold or regenerative material

Energy Technology Data Exchange (ETDEWEB)

Pon-On, Weeraphat, E-mail: fsciwpp@ku.ac.th [Department of Physics, Faculty of Science, Kasetsart University, Bangkok (Thailand); Suntornsaratoon, Panan [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Charoenphandhu, Narattaphol [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand); Thongbunchoo, Jirawan [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Krishnamra, Nateetip [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand); Tang, I. Ming [Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand)

2016-05-01

The present paper studies the physico-chemical, bioactivity and biological properties of hydroxyapatite (HA) which is derived from fish scale (FS) (FSHA) and compares them with those of synthesized HA (sHA) obtained by co-precipitation from chemical solution as a standard. The analysis shows that the FSHA is composed of flat-plate nanocrystal with a narrow width size of about 15–20 nm and having a range of 100 nm in length and that the calcium phosphate ratio (Ca/P) is 2.01 (Ca-rich CaP). Whereas, synthesized HA consists of sub-micron HA particle having a Ca/P ratio of 1.65. Bioactivity test shows that the FSHA forms more new apatite than does the sHA after being incubated in simulated body fluid (SBF) for 7 days. Moreover, the biocompatibility study shows a higher osteoblast like cell adhesion on the FSHA surface than on the sHA substrate after 3 days of culturing. Our results also show the shape of the osteoblast cells on the FSHA changes from being a rounded shape to being a flattened shape reflecting its spreading behavior on this surface. MTT assay and ALP analysis show significant increases in the proliferation and activity of osteoblasts over the FSHA scaffold after 5 days of culturing as compared to those covering the sHA substrates. These results confirm that the bio-materials derived from fish scale (FSHA) are biologically better than the chemically synthesized HA and have the potential for use as a bone scaffold or as regenerative materials. - Highlights: • Preparation of hydroxyapatite (HA) which is derived from fish scale (FS) (FSHA) and their bioactivities • The FSHA is composed of flat-plate nanocrystal with a narrow size of 15–20 nm. • Bioactivity test shows that the FSHA forms more new apatite than does the sHA after being incubated SBF. • In vitro cell availability tests show a higher cell adhesion on the FSHA surface.

DNA damage evaluation of hydroxyapatite on fibroblast cell L929 using the single cell gel electrophoresis assay.

Science.gov (United States)

Rajab, N F; Yaakob, T A; Ong, B Y; Hamid, M; Ali, A M; Annuar, B O; Inayat-Hussain, S H

2004-05-01

Hydroxyapatite is the main component of the bone which is a potential biomaterial substance that can be applied in orthopaedics. In this study, the biocompatibility of this biomaterial was assessed using an in vitro technique. The cytotoxicity and genotoxicity effect of HA2 and HA3 against L929 fibroblast cell was evaluated using the MTT Assay and Alkaline Comet Assay respectively. Both HA2 and HA3 compound showed low cytotoxicity effect as determined using MTT Assay. Cells viability following 72 hours incubation at maximum concentration of both HA2 and HA3 (200 mg/ml) were 75.3 +/- 8.8% and 86.7 +/- 13.1% respectively. However, the cytotoxicity effect of ZnSO4.7H2O as a positive control showed an IC50 values of 46 mg/ml (160 microM). On the other hand, both HA2 and HA3 compound showed a slight genotoxicity effect as determined using the Alkaline Comet Assay following incubation at the concentration 200 mg/ml for 72 hours. This assay has been widely used in genetic toxicology to detect DNA strand breaks and alkali-labile site. The percentage of the cells with DNA damage for both substance was 27.7 +/- 1.3% and 15.6 +/- 1.0% for HA2 and HA3 respectively. Incubation of the cells for 24 hours with 38 microg/ml (IC25) of positive control showed an increase in percentage of cells with DNA damage (67.5 +/- 0.7%). In conclusion, our study indicated that both hydroxyapatite compounds showed a good biocompatibility in fibroblast cells.

Optical study of plasma sprayed hydroxyapatite coatings deposited at different spray distance

Science.gov (United States)

Belka, R.; Kowalski, S.; Żórawski, W.

2017-08-01

Series of hydroxyapatite (HA) coatings deposited on titanium substrate at different spray (plasma gun to workpiece) distance were investigated. The optical methods as dark field confocal microscopy, Raman/PL and UV-VIS spectroscopy were used for study the influence of deposition process on structural degradation of HA precursor. The hydroxyl group concentration was investigated by study the OH mode intensity in the Raman spectra. Optical absorption coefficients at near UV region were analyzed by Diffuse Reflectance Spectroscopy. PL intensity observed during Raman measurement was also considered as relation to defects concentration and degradation level. It was confirmed the different gunsubstrate distance has a great impact on structure of deposited HA ceramics.

Hydroxyapatite-armored poly(ε-caprolactone) microspheres and hydroxyapatite microcapsules fabricated via a Pickering emulsion route.

Science.gov (United States)

Fujii, Syuji; Okada, Masahiro; Nishimura, Taiki; Maeda, Hayata; Sugimoto, Tatsuya; Hamasaki, Hiroyuki; Furuzono, Tsutomu; Nakamura, Yoshinobu

2012-05-15

Hydroxyapatite (HAp) nanoparticle-armored poly(ε-caprolactone) (PCL) microspheres were fabricated via a "Pickering-type" emulsion solvent evaporation method in the absence of any molecular surfactants. It was clarified that the interaction between carbonyl/carboxylic acid groups of PCL and the HAp nanoparticles at an oil-water interface played a crucial role in the preparation of the stable Pickering-type emulsions and the HAp nanoparticle-armored microspheres. The HAp nanoparticle-armored PCL microspheres were characterized in terms of size, size distribution, morphology, and chemical compositions using scanning electron microscopy, laser diffraction, energy dispersive X-ray microanalysis, and thermogravimetric analysis. The presence of HAp nanoparticles at the surface of the microspheres was confirmed by scanning electron microscopy and energy dispersive X-ray microanalysis. Pyrolysis of the PCL cores led to the formation of the corresponding HAp hollow microcapsules. Copyright © 2012 Elsevier Inc. All rights reserved.

Degradation behavior of hydroxyapatite/poly(lactic-co-glycolic) acid nanocomposite in simulated body fluid

International Nuclear Information System (INIS)

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

2013-01-01

Graphical abstract: In this manuscript, we initiated a systematic study to investigate the effect of HA on thermal properties, inner structure, reduction of mechanical strength, surface morphology and the surface deposit of n-HA/PLGA composite with respect to the soaking time. The results showed that n-HA played an important role in improving the degradation behavior of n-HA/PLGA composite, which can accelerate the degradation of n-HA/PLGA composite and endow it with bioactivity, after n-HA was detached from PLGA during the degradation, so that n-HA/PLGA composite may have a more promising prospect of the clinical application than pure PLGA as bone fracture internal fixation materials, and the results would be of reference significance to predict the in vivo degradation and biological properties. - Highlights: • Effect of n-HA on degradation behavior of n-HA/PLGA composite was investigated. • Degradation behaviors of n-HA/PLGA and PLGA were carried out in SBF for 6 months. • Viscosity, thermal properties, inner structure and bending strength were tested. • n-HA can accelerate the degradation and endows it with bioactivity. - Abstract: To investigate the effect of hydroxyapatite(HA) on the degradation behavior of hydroxyapatite/poly(lactic-co-glycolic) acid (HA/PLGA) nanocomposite, the degradation experiment of n-HA/PLGA composite and pure PLGA were carried out by soaking in simulated body fluid(SBF) at 37 °C for 1, 2, 4 and 6 months. The change of intrinsic viscosity, thermal properties, inner structure, bending strength reduction, surface morphology and the surface deposit of n-HA/PLGA composite and pure PLGA with respect to the soaking time were investigated by means of UbbeloHde Viscometer, differential scanning calorimeter (DSC), scanning electron microscope(SEM), electromechanical universal tester, a conventional camera and X-ray diffraction (XRD). The results showed that n-HA played an important role in improving the degradation behavior of n-HA

Facile synthesis of both needle-like and spherical hydroxyapatite nanoparticles: Effect of synthetic temperature and calcination on morphology, crystallite size and crystallinity

International Nuclear Information System (INIS)

Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Premalal, E.V.A.; Herath, H.M.T.U.; Mahalingam, S.; Edirisinghe, M.; Rajapakse, R.P.V.J.; Rajapakse, R.M.G.

2014-01-01

Synthetic hydroxyapatite (HA) nanoparticles, that mimic natural HA, are widely used as biocompatible coatings on prostheses to repair and substitute human bones. In this study, HA nanoparticles are prepared by precipitating them from a precursor solution containing calcium sucrate and ammonium dihydrogen orthophosphate, at a Ca/P mole ratio of 1.67:1, at temperatures, ranging from 10 °C to 95 °C. A set of products, prepared at different temperatures, is analyzed for their crystallinity, crystallite size, morphology, thermal stability and composition, by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopic techniques, while the other set is analyzed after calcining the respective products, soon after their synthesis, for 3 h, at 700 °C. The as-prepared products, after 2 h of drying, without any calcination, are not crystalline, but they grow very slowly into needle-like morphologies, as they are ripened with time. The percentage crystallinity of the final products increases from 15% to 52%, with increasing the preparative temperature. The calcined samples always produce spherical nanoparticles of essentially the same diameter, between 90 nm and 100 nm, which does not change due to aging and preparative temperatures. Therefore, the same method can be utilized to synthesize both spherical and needle-like nanoparticles of hydroxyapatite, with well-defined sizes and shapes. The ability to use readily available cheap raw materials, for the synthesis of such well-defined crystallites of hydroxyapatite, is an added advantage of this method, which may be explored further for the scaling up of the procedures to suit to industrial scale synthesis of such hydroxyapatite nanoparticles. - Highlights: • Hydroxyapatite nanoparticles are synthesized using a simple precipitation method. • Both needle-like and spherical hydroxyapatite nanoparticles are synthesized. • The prepared

Facile synthesis of both needle-like and spherical hydroxyapatite nanoparticles: Effect of synthetic temperature and calcination on morphology, crystallite size and crystallinity

Energy Technology Data Exchange (ETDEWEB)

Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G. [Department of Chemistry, Faculty of Science, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Post-graduate Institute of Science, P.O. Box: 25, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Premalal, E.V.A. [Department of Materials Science, Shizuoka University, Johoku, Naka-ku Hamamatsu, 432-8011 (Japan); Herath, H.M.T.U. [Department of Medical Laboratory Science, Faculty of Allied Health Sciences, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Mahalingam, S.; Edirisinghe, M. [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Rajapakse, R.P.V.J. [Department of Veterinary Pathobiology, Faculty of Veterinary, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Rajapakse, R.M.G., E-mail: rmgr@pdn.ac.lk [Department of Chemistry, Faculty of Science, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Post-graduate Institute of Science, P.O. Box: 25, University of Peradeniya, Peradeniya 20400 (Sri Lanka)

2014-09-01

Synthetic hydroxyapatite (HA) nanoparticles, that mimic natural HA, are widely used as biocompatible coatings on prostheses to repair and substitute human bones. In this study, HA nanoparticles are prepared by precipitating them from a precursor solution containing calcium sucrate and ammonium dihydrogen orthophosphate, at a Ca/P mole ratio of 1.67:1, at temperatures, ranging from 10 °C to 95 °C. A set of products, prepared at different temperatures, is analyzed for their crystallinity, crystallite size, morphology, thermal stability and composition, by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopic techniques, while the other set is analyzed after calcining the respective products, soon after their synthesis, for 3 h, at 700 °C. The as-prepared products, after 2 h of drying, without any calcination, are not crystalline, but they grow very slowly into needle-like morphologies, as they are ripened with time. The percentage crystallinity of the final products increases from 15% to 52%, with increasing the preparative temperature. The calcined samples always produce spherical nanoparticles of essentially the same diameter, between 90 nm and 100 nm, which does not change due to aging and preparative temperatures. Therefore, the same method can be utilized to synthesize both spherical and needle-like nanoparticles of hydroxyapatite, with well-defined sizes and shapes. The ability to use readily available cheap raw materials, for the synthesis of such well-defined crystallites of hydroxyapatite, is an added advantage of this method, which may be explored further for the scaling up of the procedures to suit to industrial scale synthesis of such hydroxyapatite nanoparticles. - Highlights: • Hydroxyapatite nanoparticles are synthesized using a simple precipitation method. • Both needle-like and spherical hydroxyapatite nanoparticles are synthesized. • The prepared

Electric field-assisted formation of organically modified hydroxyapatite (ormoHAP) spheres in carboxymethylated gelatin gels.

Science.gov (United States)

Heinemann, C; Heinemann, S; Kruppke, B; Worch, H; Thomas, J; Wiesmann, H P; Hanke, T

2016-10-15

A biomimetic strategy was developed in order to prepare organically modified hydroxyapatite (ormoHAP) with spherical shape. The technical approach is based on electric field-assisted migration of calcium ions and phosphate ions into a hydrogel composed of carboxymethylated gelatin. The electric field as well as the carboxymethylation using glucuronic acid (GlcA) significantly accelerates the mineralization process, which makes the process feasible for lab scale production of ormoHAP spheres and probably beyond. A further process was developed for gentle separation of the ormoHAP spheres from the gelatin gel without compromising the morphology of the mineral. The term ormoHAP was chosen since morphological analyses using electron microscopy (SEM, TEM) and element analysis (EDX, FT-IR, XRD) confirmed that carboxymethylated gelatin molecules use to act as organic templates for the formation of nanocrystalline HAP. The hydroxyapatite (HAP) crystals self-organize to form hollow spheres with diameters ranging from 100 to 500nm. The combination of the biocompatible chemical composition and the unique structure of the nanocomposites is considered to be a useful basis for future applications in functionalized degradable biomaterials. A novel bioinspired mineralization process was developed based on electric field-assisted migration of calcium and phosphate ions into biochemically carboxymethylated gelatin acting as organic template. Advantages over conventional hydroxyapatite include particle size distribution and homogeneity as well as achievable mechanical properties of relevant composites. Moreover, specifically developed calcium ion or phosphate ion release during degradation can be useful to adjust the fate of bone cells in order to manipulate remodeling processes. The hollow structure of the spheres can be useful for embedding drugs in the core, encapsulated by the highly mineralized outer shell. In this way, controlled drug release could be achieved, which enables

Hydroxyapatite coating on PEEK implants: Biomechanical and histological study in a rabbit model

Energy Technology Data Exchange (ETDEWEB)

Durham, John W. [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Montelongo, Sergio A.; Ong, Joo L.; Guda, Teja [Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX 78249 (United States); Allen, Matthew J. [Department of Veterinary Medicine, University of Cambridge, Cambridge (United Kingdom); Rabiei, Afsaneh, E-mail: arabiei@ncsu.edu [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

2016-11-01

A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK. The in vivo response to cylindrical PEEK samples with and without coating was studied by implanting uncoated PEEK and coated PEEK implants in the lateral femoral condyle of 18 rabbits. Animals were studied in two groups of 9 for observation at 6 or 18 weeks post surgery. Micro-CT analysis, histology, and mechanical pull-out tests were performed to determine the effect of the coating on osseointegration. The heat-treated HA/YSZ coatings showed improved implant fixation as well as higher bone regeneration and bone-implant contact area compared to uncoated PEEK. The study offers a novel method to coat PEEK implants with improved osseointegration. - Highlights: • Method for improving osseointegration of PEEK implants is analyzed in vivo. • Uniform multilayer coatings were deposited on cylindrical PEEK implants. • Microwave and hydrothermal heat treatments crystallized the hydroxyapatite coating. • Healing response shows coated implants increase bone growth and implant fixation.

Hydroxyapatite coating on PEEK implants: Biomechanical and histological study in a rabbit model

International Nuclear Information System (INIS)

Durham, John W.; Montelongo, Sergio A.; Ong, Joo L.; Guda, Teja; Allen, Matthew J.; Rabiei, Afsaneh

2016-01-01

A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK. The in vivo response to cylindrical PEEK samples with and without coating was studied by implanting uncoated PEEK and coated PEEK implants in the lateral femoral condyle of 18 rabbits. Animals were studied in two groups of 9 for observation at 6 or 18 weeks post surgery. Micro-CT analysis, histology, and mechanical pull-out tests were performed to determine the effect of the coating on osseointegration. The heat-treated HA/YSZ coatings showed improved implant fixation as well as higher bone regeneration and bone-implant contact area compared to uncoated PEEK. The study offers a novel method to coat PEEK implants with improved osseointegration. - Highlights: • Method for improving osseointegration of PEEK implants is analyzed in vivo. • Uniform multilayer coatings were deposited on cylindrical PEEK implants. • Microwave and hydrothermal heat treatments crystallized the hydroxyapatite coating. • Healing response shows coated implants increase bone growth and implant fixation.

Fabrication of polymeric hollow nanospheres, hollow nanocubes and hollow plates

Science.gov (United States)

Cheng, Daming; Xia, Haibing; Chan, Hardy Sze On

2006-03-01

A facile strategy for fabricating polypyrrole-chitosan (PPy-CS) hollow nanostructures with different shapes (sphere, cube and plate) and a wide range of sizes (from 35 to 600 nm) is described. These hollow structures have been fabricated using silver bromide as a single template material for polymer nucleation and growth. PPy-CS hollow nanostructures are formed by reaction with an etching agent to remove the core. These hollow nanostructures have been extensively characterized using various techniques such as TEM, FT-IR, UV-vis, and XRD.

Exploiting the high-affinity phosphonate-hydroxyapatite nanoparticle interaction for delivery of radiation and drugs

International Nuclear Information System (INIS)

Ong, Hooi Tin; Loo, Joachim S. C.; Boey, Freddy Y. C.; Russell, Stephen J.; Ma Jan; Peng, Kah-Whye

2008-01-01

Hydroxyapatite is biocompatible and used in various biomedical applications. Here, we generated hydroxyapatite nanoparticles (HNPs) of various sizes (40-200 nm) and demonstrated that they can be stably loaded with drugs or radioisotopes by exploiting the high-affinity HA-(poly)phosphonate interaction. Clinically available phosphonates, clodronate, and Tc-99m-methylene-diphosphonate (Tc-99m-MDP), were efficiently loaded onto HNPs within 15 min. Biodistribution of radiolabeled HNP-MDP-Tc99m in mice was monitored non-invasively using microSPECT-CT. Imaging and dosimetry studies indicated that the HNPs, regardless of size, were quickly taken up by Kupffer cells in the liver after systemic administration into mice. Clodronate loaded onto HNPs remained biologically active and were able to result in selective depletion of Kupffer cells. This method of drug or isotope loading on HA is fast and easy as it eliminates the need for additional surface modifications of the nanoparticles

A graded graphene oxide-hydroxyapatite/silk fibroin biomimetic scaffold for bone tissue engineering.

Science.gov (United States)

Wang, Qian; Chu, Yanyan; He, Jianxin; Shao, Weili; Zhou, Yuman; Qi, Kun; Wang, Lidan; Cui, Shizhong

2017-11-01

To better mimic natural bone, a graphene oxide-hydroxyapatite/silk fibroin (cGO-HA/SF) scaffold was fabricated by biomineralizing carboxylated GO sheets, blending with SF, and freeze-drying. The material has increasing porosity and decreasing density from outside to inside. Analysis of GO mineralization in simulated body fluid indicated that carboxylation and Chitosan may synergistically regulate HA growth along the c-axis of weakly crystalline, rod-like GO-HA particles. Compared with HA/SF gradient composites, a cGO-HA gradient scaffold with cGO:HA mass ratio 1:4 has 5-fold and 2.5-fold higher compressive strength and compressive modulus, respectively. Additionally, the cGO-HA/SF composite stimulated mouse mesenchymal stem cell adhesion and proliferation, alkaline phosphatase secretion, and mineral deposition more strongly than HA/SF and pure HA scaffolds. Hence, the material may prove to be an excellent and versatile scaffold for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

Bone tissue engineering with a collagen–hydroxyapatite scaffold and culture expanded bone marrow stromal cells

Science.gov (United States)

Villa, Max M.; Wang, Liping; Huang, Jianping; Rowe, David W.; Wei, Mei

2015-01-01

Osteoprogenitor cells combined with supportive biomaterials represent a promising approach to advance the standard of care for bone grafting procedures. However, this approach faces challenges, including inconsistent bone formation, cell survival in the implant, and appropriate biomaterial degradation. We have developed a collagen–hydroxyapatite (HA) scaffold that supports consistent osteogenesis by donor derived osteoprogenitors, and is more easily degraded than a pure ceramic scaffold. Herein, the material properties are characterized as well as cell attachment, viability, and progenitor distribution in vitro. Furthermore, we examined the biological performance in vivo in a critical-size mouse calvarial defect. To aid in the evaluation of the in-house collagen–HA scaffold, the in vivo performance was compared with a commercial collagen–HA scaffold (Healos®, Depuy). The in-house collagen–HA scaffold supported consistent bone formation by predominantly donor-derived osteoblasts, nearly completely filling a 3.5 mm calvarial defect with bone in all samples (n=5) after 3 weeks of implantation. In terms of bone formation and donor cell retention at 3 weeks postimplantation, no statistical difference was found between the in-house and commercial scaffold following quantitative histomorphometry. The collagen–HA scaffold presented here is an open and well-defined platform that supports robust bone formation and should facilitate the further development of collagen–hydroxyapatite biomaterials for bone tissue engineering. PMID:24909953

Hydrothermal fabrication of hydroxyapatite on the PEG-grafted surface of wood from Chinese Glossy Privet

Science.gov (United States)

Wang, Ning; Cai, Chuanjie; Cai, Dongqing; Cheng, Junjie; Li, Shengli; Wu, Zhengyan

2012-10-01

Wood-hydroxyapatite composite material was developed by depositing hydrated calcium hydrogen phosphate (HCHP) on the surface of wood from Chinese Glossy Privet (CGP) with polyethylene glycol (PEG, HO(CH2CH2O)nH) as the grafting agent and subsequent hydrothermal vapor treatment. The results illustrated that HCHP could adhere quickly and strongly on the PEG-grafted wood surface. Moreover, this HCHP could be efficiently transformed to hydroxyapatite (HA, Ca10(PO4)6(OH)2) by hydrothermal vapor treatment. IR, XRD analysis and SEM observation indicated that the fabricated hydroxyapatite was pure and its morphology was uniform and microporous. This work provides a new fabricating approach of biocompatible material which may have some potential applications as bone-repairing material.

Synthesis of fluorapatite–hydroxyapatite nanoparticles and toxicity investigations

Directory of Open Access Journals (Sweden)

N Montazeri

2011-01-01

Full Text Available N Montazeri, R Jahandideh, Esmaeil BiazarDepartment of Chemistry, Islamic Azad University-Tonekabon Branch, Mazandaran, IranAbstract: In this study, calcium phosphate nanoparticles with two phases, fluorapatite (FA; Ca10(PO46F2 and hydroxyapatite (HA; Ca10(PO46(OH2, were prepared using the sol-gel method. Ethyl phosphate, hydrated calcium nitrate, and ammonium fluoride were used, respectively, as P, Ca, and F precursors with a Ca:P ratio of 1:72. Powders obtained from the sol-gel process were studied after they were dried at 80°C and heat treated at 550°C. The degree of crystallinity, particle and crystallite size, powder morphology, chemical structure, and phase analysis were investigated by scanning electron microscopy (SEM, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, and Zetasizer experiments. The results of XRD analysis and FTIR showed the presence of hydroxyapatite and fluorapatite phases. The sizes of the crystallites estimated from XRD patterns using the Scherrer equation and the crystallinity of the hydroxyapatite phase were about 20 nm and 70%, respectively. Transmission electron microscope and SEM images and Zetasizer experiments showed an average size of 100 nm. The in vitro behavior of powder was investigated with mouse fibroblast cells. The results of these experiments indicated that the powders were biocompatibile and would not cause toxic reactions. These compounds could be applied for hard-tissue engineering.Keywords: fluorapatite, hydroxyapatite, sol-gel, nanoparticles, biocompatibility

Improved cell viability and hydroxyapatite growth on nitrogen ion-implanted surfaces

Science.gov (United States)

Shafique, Muhammad Ahsan; Murtaza, G.; Saadat, Shahzad; Uddin, Muhammad K. H.; Ahmad, Riaz

2017-08-01

Stainless steel 306 is implanted with various doses of nitrogen ions using a 2 MV pelletron accelerator for the improvement of its surface biomedical properties. Raman spectroscopy reveals incubation of hydroxyapatite (HA) on all the samples and it is found that the growth of incubated HA is greater in higher ion dose samples. SEM profiles depict uniform growth and greater spread of HA with higher ion implantation. Human oral fibroblast response is also found consistent with Raman spectroscopy and SEM results; the cell viability is found maximum in samples treated with the highest (more than 300%) dose. XRD profiles signified greater peak intensity of HA with ion implantation; a contact angle study revealed hydrophilic behavior of all the samples but the treated samples were found to be lesser hydrophilic compared to the control samples. Nitrogen implantation yields greater bioactivity, improved surface affinity for HA incubation and improved hardness of the surface.

Synthesis of Hydroxyapatite/Ag/TiO2 Nanotubes and Evaluation of Their Anticancer Activity on Breast Cancer Cell Line MCF-7

Directory of Open Access Journals (Sweden)

Sara Rahimnejad

2016-06-01

Full Text Available In this research, TiO2 nanotubes were synthesized by anodized oxidation method and were covered with a hydroxyapatite-silver nanoparticles using photodeposition and dip coating for loading silver nanoparticles and coated hydroxyapatite (HA. The morphological texture of TiO2 nanotube and Ag-HA nanoparticles on TiO2 nanotubes surface were studied by field emission scanning electron microscopy (FESEM, energy dispersive X-ray spectroscopy (EDAX analysis and X-ray diffraction (XRD. The MCF-7 cell lines were treated with concentrations 1, 10 and 100 µg/ml of TiO2 nanotubes and HA/Ag/TiO2 nanotube for 24 and 48h. Finally, the cell viability and IC50% were evaluated using MTT assay. The results show that the HA/Ag/TiO2 has more positive effect on enhancing the cell death compare to TiO2 nanotubes and also exerts a time and concentration-dependent inhibition effect on viability of MCF-7 cells

Synthesis of chitosan/hydroxyapatite membranes coated with hydroxycarbonate apatite for guided tissue regeneration purposes

Energy Technology Data Exchange (ETDEWEB)

Fraga, Alexandre Felix [Federal University of Sao Carlos, Department of Materials Engineering, DEMa, UFSCar, Sao Carlos, SP (Brazil); Almeida Filho, Edson de, E-mail: edsonafilho@yahoo.com.br [University Estadual Paulista, Department of Physical Chemistry - IQ, Araraquara, SP (Brazil); Silva Rigo, Eliana Cristina da [University of Sao Paulo, Department of Basic Science - FZEA-ZAB, Pirassununga, SP (Brazil); Ortega Boschi, Anselmo [Federal University of Sao Carlos, Department of Materials Engineering, DEMa, UFSCar, Sao Carlos, SP (Brazil)

2011-02-15

Chitosan, which is a non-toxic, biodegradable and biocompatible biopolymer, has been widely researched for several applications in the field of biomaterials. Calcium phosphate ceramics stand out among the so-called bioceramics for their absence of local or systemic toxicity, their non-response to foreign bodies or inflammations, and their apparent ability to bond to the host tissue. Hydroxyapatite (HA) is one of the most important bioceramics because it is the main component of the mineral phase of bone. The aim of this work was to produce chitosan membranes coated with hydroxyapatite using the modified biomimetic method. Membranes were synthesized from a solution containing 2% of chitosan in acetic acid (weight/volume) via the solvent evaporation method. Specimens were immersed in a sodium silicate solution and then in a 1.5 SBF (simulated body fluid) solution. The crystallinity of the HA formed over the membranes was correlated to the use of the nucleation agent (the sodium silicate solution itself). Coated membranes were characterized by means of scanning electron microscopy - SEM, X-ray diffraction - XRD, and Fourier transform infrared spectroscopy - FTIR. The results indicate a homogeneous coating covering the entire surface of the membrane and the production of a semi-crystalline hydroxyapatite layer similar to the mineral phase of human bone.

Mesoporous hydroxyapatite: Preparation, drug adsorption, and release properties

Energy Technology Data Exchange (ETDEWEB)

Gu, Lina; He, Xiaomei; Wu, Zhenyu, E-mail: zhenyuwuhn@sina.com

2014-11-14

Mesoporous hydroxyapatite (HA) was synthesized through gas–liquid chemical precipitation method at ambient temperature without any template. Structure, morphology and pore size distribution of HA were analyzed via X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution electron microscopy and N{sub 2} adsorption/desorption. The chemotherapeutic agent doxorubicin (DOX) was used to investigate the drug adsorption and release behavior of HA. The kinetics of DOX adsorption on HA followed the pseudo-second-order rate expression. Adsorption isotherms at various temperatures were obtained, and the equilibrium data fitted the Langmuir model. The values of thermodynamic parameters (Gibbs free energy, entropy, and enthalpy changes) demonstrated that the adsorption process was spontaneous and endothermic. In vitro pH-responsive (pH = 7.4, 5.8) controlled release was investigated. DOX-loaded HA showed a slow, long-term, and steady release rate. The release rate at pH5.8 was larger than that at pH7.4. Consequently, the as-prepared mesoporous HA has potential applications in controlled drug delivery systems. - Highlights: • Mesoporous HA was synthesized by a simple precipitation method without any template. • The kinetics of adsorption followed the pseudo-second-order rate expression. • Thermodynamics investigation showed that adsorption was spontaneous and endothermic. • DOX-loaded HA showed a long-term, steady, and pH-controlled release rate.

New nano-hydroxyapatite in bone defect regeneration: A histological study in rats.

Science.gov (United States)

Kubasiewicz-Ross, Paweł; Hadzik, Jakub; Seeliger, Julia; Kozak, Karol; Jurczyszyn, Kamil; Gerber, Hanna; Dominiak, Marzena; Kunert-Keil, Christiane

2017-09-01

Many types of bone substitute materials are available on the market. Researchers are refining new bone substitutes to make them comparable to autologous grafting materials in treatment of bone defects. The purpose of the study was to evaluate the osseoconductive potential and bone defect regeneration in rat calvaria bone defects treated with new synthetic nano-hydroxyapatite. The study was performed on 30 rats divided into 5 equal groups. New preproduction of experimental nano-hydroxyapatite material by NanoSynHap (Poznań, Poland) was tested and compared with commercially available materials. Five mm critical size defects were created and filled with the following bone grafting materials: 1) Geistlich Bio-Oss ® ; 2) nano-hydroxyapatite+β-TCP; 3) nano-hydroxyapatite; 4) nano-hydroxyapatite+collagen membrane. The last group served as controls without any augmentation. Bone samples from calvaria were harvested for histological and micro-ct evaluation after 8 weeks. New bone formation was observed in all groups. Histomorphometric analysis revealed an amount of regenerated bone between 34.2 and 44.4% in treated bone defects, whereas only 13.0% regenerated bone was found in controls. Interestingly, in group 3, no significant particles of the nano-HA material were found. In contrast, residual bone substitute material could be detected in all other test groups. Micro-CT study confirmed the results of the histological examinations. The new nano-hydroxyapatite provides comparable results to other grafts in the field of bone regeneration. Copyright © 2017 Elsevier GmbH. All rights reserved.

Nano hydroxyapatite-blasted titanium surface affects pre-osteoblast morphology by modulating critical intracellular pathways.

Science.gov (United States)

Bezerra, Fábio; Ferreira, Marcel R; Fontes, Giselle N; da Costa Fernandes, Célio Jr; Andia, Denise C; Cruz, Nilson C; da Silva, Rodrigo A; Zambuzzi, Willian F

2017-08-01

Although, intracellular signaling pathways are proposed to predict the quality of cell-surface relationship, this study addressed pre-osteoblast behavior in response to nano hydroxyapatite (HA)-blasted titanium (Ti) surface by exploring critical intracellular pathways and pre-osteoblast morphological change. Physicochemical properties were evaluated by atomic force microscopy (AFM) and wettability considering water contact angle of three differently texturized Ti surfaces: Machined (Mac), Dual acid-etching (DAE), and nano hydroxyapatite-blasted (nHA). The results revealed critical differences in surface topography, impacting the water contact angle and later the osteoblast performance. In order to evaluate the effect of those topographical characteristics on biological responses, we have seeded pre-osteoblast cells on the Ti discs for up to 4 h and subjected the cultures to biological analysis. First, we have observed pre-osteoblasts morphological changes resulting from the interaction with the Ti texturized surfaces whereas the cells cultured on nHA presented a more advanced spreading process when compared with the cells cultured on the other surfaces. These results argued us for analyzing the molecular machinery and thus, we have shown that nHA promoted a lower Bax/Bcl2 ratio, suggesting an interesting anti-apoptotic effect, maybe explained by the fact that HA is a natural element present in bone composition. Thereafter, we investigated the potential effect of those surfaces on promoting pre-osteoblast adhesion and survival signaling by performing crystal violet and immunoblotting approaches, respectively. Our results showed that nHA promoted a higher pre-osteoblast adhesion supported by up-modulating FAK and Src activations, both signaling transducers involved during eukaryotic cell adhesion. Also, we have shown Ras-Erk stimulation by the all evaluated surfaces. Finally, we showed that all Ti-texturing surfaces were able to promote osteoblast differentiation

Assessment of polycaprolacton (PCL) nanocomposite scaffold compared with hydroxyapatite (HA) on healing of segmental femur bone defect in rabbits.

Science.gov (United States)

Eftekhari, Hadi; Jahandideh, Alireza; Asghari, Ahmad; Akbarzadeh, Abolfazl; Hesaraki, Saeed

2017-08-01

Segmental bone loss due to trauma, infection, and tumor resection and even non-union results in the vast demand for replacement and restoration of the function of the lost bone. The objective of this study is to utilize novel inorganic-organic nanocomposites for biomedical applications. Biodegradable implants have shown great promise for the repair of bone defects and have been commonly used as bone substitutes, which traditionally would be treated using metallic implants. In this study, 45 mature male New Zealand white rabbits 6-8 months and weighting 3-3.5 kg were examined. Rabbits were divided into three groups. Surgical procedures were done after an intramuscular injection of Ketamine 10% (ketamine hydrochloride, 50 mg/kg), Rompun 5% (xylazine, 5 mg/kg). Then an approximately 6 mm diameter - 5 mm cylinder bone defect was created in the femur of one of the hind limbs. After inducing the surgical wound, all rabbits were colored and randomly divided into three experimental groups of nine animals each: Group 1 received medical pure nanocomposite polycaprolactone (PCL) granules, Group 2 received hydroxyapatite and Group 3 was a control group with no treatment. Histopathological evaluation was performed on days 15, 30 and 45 after surgery. On day 45 after surgery, the quantity of newly formed lamellar bone in the healing site in PCL group was better than onward compared with HA and control groups. Finally, nanocomposite PCL granules exhibited a reproducible bone-healing potential.

Hierarchically nanostructured hydroxyapatite: hydrothermal synthesis, morphology control, growth mechanism, and biological activity

Directory of Open Access Journals (Sweden)

Ma MG

2012-04-01

Full Text Available Ming-Guo MaInstitute of Biomass Chemistry and Technology, College of Materials Science and Technology, Beijing Forestry University, Beijing, People's Republic of ChinaAbstract: Hierarchically nanosized hydroxyapatite (HA with flower-like structure assembled from nanosheets consisting of nanorod building blocks was successfully synthesized by using CaCl2, NaH2PO4, and potassium sodium tartrate via a hydrothermal method at 200°C for 24 hours. The effects of heating time and heating temperature on the products were investigated. As a chelating ligand and template molecule, the potassium sodium tartrate plays a key role in the formation of hierarchically nanostructured HA. On the basis of experimental results, a possible mechanism based on soft-template and self-assembly was proposed for the formation and growth of the hierarchically nanostructured HA. Cytotoxicity experiments indicated that the hierarchically nanostructured HA had good biocompatibility. It was shown by in-vitro experiments that mesenchymal stem cells could attach to the hierarchically nanostructured HA after being cultured for 48 hours.Objective: The purpose of this study was to develop facile and effective methods for the synthesis of novel hydroxyapatite (HA with hierarchical nanostructures assembled from independent and discrete nanobuilding blocks.Methods: A simple hydrothermal approach was applied to synthesize HA by using CaCl2, NaH2PO4, and potassium sodium tartrate at 200°C for 24 hours. The cell cytotoxicity of the hierarchically nanostructured HA was tested by MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay.Results: HA displayed the flower-like structure assembled from nanosheets consisting of nanorod building blocks. The potassium sodium tartrate was used as a chelating ligand, inducing the formation and self-assembly of HA nanorods. The heating time and heating temperature influenced the aggregation and morphology of HA. The cell viability did

Chronic Orbital Inflammation Associated to Hydroxyapatite Implants in Anophthalmic Sockets

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Alicia Galindo-Ferreiro

2017-12-01

Full Text Available Purpose: We report 6 patients who received a hydroxyapatite (HA orbital implant in the socket and developed chronic orbital inflammation unresponsive to conventional medical therapy. Case Reports: We assisted 6 cases (4 males, 2 females who received an HA orbital implant in the socket between 2015 and 2016 at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia, and developed chronic orbital inflammation with chronic discharge, redness, and pain (onset from weeks to over 2 decades after surgery. Computed tomography evaluation indicated inflammation in the orbital tissues, and histological examination showed a foreign body granulomatous reaction mainly localized around and blanching the HA implant. The condition was unresponsive to usual medical treatment and was resolved immediately after implant removal. Conclusions: Chronic inflammation can occur decades after placement of an HA implant in the orbit and can be successfully treated with implant removal.

A study of 153Sm-citrate-hydroxyapatite synovectomy in knee synovitis with rheumatoid arthritis

International Nuclear Information System (INIS)

Fan Yanggang; Li Guohua; Yao Guozhong; Zhang Qingcheng; Li Guangming

2006-01-01

Objective: To investigate the efficacy and safety of 153 Sm-citrate-hydroxyapatite (HA) synovectomy in knee synovitis with rheumatoid arthritis (RA). Methods: In 43 RA patients ineffective to routine anti-rheumatic drugs (DMMARDs) therapy, radiation synovectomy was performed by 153 Sm-citrate-HA in 67 joints and its efficacy and safety were evaluated. Results: Radioactivity was evenly distributed as observed by gamma camera after injection. In 8 cases leakage of radioactivity was detected after 24 h, and accounted to 153 Sm-citrate-HA synovectomy is effective after short-term and medium-term follow-up and it is a safe procedure. (authors)

Effect of the addition of collagen in the preparation of hydroxyapatite, aiming the application of pulp capping

International Nuclear Information System (INIS)

Ribeiro, Geysy L.; Mendes, Luis C.

2011-01-01

This work studied the action of collagen (COLL) in the hydroxyapatite (HA) synthesis, produced through sol-gel process, in order to mimetize the chemical composition of dental tissue. The resulting material was characterized by energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), wide-angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The Ca/P ratio was determined through EDX - 1,89 e 2,38, with and without collagen, respectively. The FT-IR analysis showed no significant interaction between the constituents of the composite. The R-ray diffractograms indicated an increase of the resolution and intensity of the HA peak. The photomicrographies showed that the preparation method exhibited significantly influence onto the hydroxyapatite morphology, as well as resulted in a homogeneously dispersed composite. (author)

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.

Investigation of morphology and bioactive properties of composite coating of HA/vinyl acetate on pure titanium

International Nuclear Information System (INIS)

Afshar, Abdollahe; Yousefpour, Mardali; Xiudong, Yang; Li Xudong; Yang Bangcheng; Wu Yao; Chen Jiyong; Zhang Xingdong

2006-01-01

Electrochemical co-deposition approach was expanded to prepare composite bio-ceramic coating of hydroxyapatite (HA)/polyvinyl acetate on the surface of titanium. The role is to improve the bioactive and crystallization properties. The results of XRD, XPS, SEM and TEM characterization showed that by increasing amount of vinyl acetate in the composite bio-ceramic coating before and after immersing in the simulated body fluid (SBF), an oriented growth of HA planes on the (0 0 2) direction had been observed on titanium substrate. Also significant surface morphology changes were obtained

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.

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.

Hydroxyapatite coatings produced on commercially pure titanium by micro-arc oxidation

Energy Technology Data Exchange (ETDEWEB)

Huang Yong [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Wang Yingjun [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Ning Chengyun [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Nan Kaihui [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Han Yong [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China)

2007-09-15

A porous hydroxyapatite (HA) coating on commercially pure titanium was prepared by micro-arc oxidation (MAO) in electrolytic solution containing calcium acetate and {beta}-glycerol phosphate disodium salt pentahydrate ({beta}-GP). The thickness, phase, composition morphology and biocompatibility of the oxide coating were characterized by x-ray diffraction (XRD), electron probe microanalysis (EPMA), scanning electron microscopy (SEM) with an energy dispersive x-ray spectrometer (EDS) and cell culture. The thickness of the MAO film was about 20 {mu}m, and the coating was porous and uneven without any apparent interface to the titanium substrates. The result of XRD showed that the porous coating was made up of HA film. The favorable osteoblast cell affinity gives HA film good biocompatibility. HA coatings are expected to have significant uses for medical applications such as dental implants and artificial bone joints.

Hydroxyapatite coatings produced on commercially pure titanium by micro-arc oxidation.

Science.gov (United States)

Huang, Yong; Wang, Yingjun; Ning, Chengyun; Nan, Kaihui; Han, Yong

2007-09-01

A porous hydroxyapatite (HA) coating on commercially pure titanium was prepared by micro-arc oxidation (MAO) in electrolytic solution containing calcium acetate and beta-glycerol phosphate disodium salt pentahydrate (beta-GP). The thickness, phase, composition morphology and biocompatibility of the oxide coating were characterized by x-ray diffraction (XRD), electron probe microanalysis (EPMA), scanning electron microscopy (SEM) with an energy dispersive x-ray spectrometer (EDS) and cell culture. The thickness of the MAO film was about 20 microm, and the coating was porous and uneven without any apparent interface to the titanium substrates. The result of XRD showed that the porous coating was made up of HA film. The favorable osteoblast cell affinity gives HA film good biocompatibility. HA coatings are expected to have significant uses for medical applications such as dental implants and artificial bone joints.

Hydroxyapatite coatings produced on commercially pure titanium by micro-arc oxidation

International Nuclear Information System (INIS)

Huang Yong; Wang Yingjun; Ning Chengyun; Nan Kaihui; Han Yong

2007-01-01

A porous hydroxyapatite (HA) coating on commercially pure titanium was prepared by micro-arc oxidation (MAO) in electrolytic solution containing calcium acetate and β-glycerol phosphate disodium salt pentahydrate (β-GP). The thickness, phase, composition morphology and biocompatibility of the oxide coating were characterized by x-ray diffraction (XRD), electron probe microanalysis (EPMA), scanning electron microscopy (SEM) with an energy dispersive x-ray spectrometer (EDS) and cell culture. The thickness of the MAO film was about 20 μm, and the coating was porous and uneven without any apparent interface to the titanium substrates. The result of XRD showed that the porous coating was made up of HA film. The favorable osteoblast cell affinity gives HA film good biocompatibility. HA coatings are expected to have significant uses for medical applications such as dental implants and artificial bone joints

Hydroxyapatite clay for gap filling and adequate bone ingrowth.

Science.gov (United States)

Maruyama, M; Terayama, K; Ito, M; Takei, T; Kitagawa, E

1995-03-01

In uncemented total hip arthroplasty, a complete filling of the gap between femoral prosthesis and the host bone is difficult and defects would remain, because the anatomy of the reamed intramedullary canal cannot fit the prosthesis. Therefore, it seems practical to fill the gap with a clay containing hydroxyapatite (HA), which has an osteoconductive character. The clay (HA clay) is made by mixing HA granules (size 0.1 mm or more) having a homogeneous pore distribution and a porosity of 35-48 vol%, and a viscous substance such as a saline solution of sodium alginate (SSSA). In the first experiment, the ratio of HA granules and sodium alginate in SSSA is set for the same handling properties of HA clay and polymethylmethacrylate bone cement (standard viscosity) before hardening. As a result, the ratio is set for 55 wt% of HA in the clay and 12.5 wt% of sodium alginate in SSSA (i.e., HA:sodium alginate:saline solution = 9.8:1:7). In the second study, the gap between the femoral stem and bone model is completely filled with HA clay. However, the gap is not filled only with HA granules or HA granules mixed with saline solution. In the third animal experiment, using an unloaded model, histology shows that HA clay has an osteoconductive property bridging the gap between the implant and the cortical bone without any adverse reaction. HA clay is considered a useful biomaterial to fill the gap with adequate bone ingrowth.

Sol-Gel-Derived Hydroxyapatite-Carbon Nanotube/Titania Coatings on Titanium Substrates

Directory of Open Access Journals (Sweden)

Chuantong Liu

2012-04-01

Full Text Available In this paper, hydroxyapatite-carbon nanotube/titania (HA-CNT/TiO₂ double layer coatings were successfully developed on titanium (Ti substrates intended for biomedical applications. A TiO₂ coating was firstly developed by anodization to improve bonding between HA and Ti, and then the layer of HA and CNTs was coated on the surface by the sol-gel process to improve the biocompatibility and mechanical properties of Ti. The surfaces of double layer coatings were uniform and crack-free with a thickness of about 7 μm. The bonding strength of the HA-CNT/TiO₂ coating was higher than that of the pure HA and HA-CNT coatings. Additionally, in vitro cell experiments showed that CNTs promoted the adhesion of preosteoblasts on the HA-CNT/TiO₂ double layer coatings. These unique surfaces combined with the osteoconductive properties of HA exhibited the excellent mechanical properties of CNTs. Therefore, the developed HA-CNT/TiO₂ coatings on Ti substrates might be a promising material for bone replacement.

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.

Ultrasound-assisted fabrication of a biocompatible magnetic hydroxyapatite.

Science.gov (United States)

Zhou, Gang; Song, Wei; Hou, Yongzhao; Li, Qing; Deng, Xuliang; Fan, Yubo

2014-10-01

This work describes the fabrication and characterization of a biocompatible magnetic hydroxyapatite (HA) using an ultrasound-assisted co-precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) were used to characterize the structure and chemical composition of the produced samples. The M-H loops of synthesized materials were traced using a vibrating sample magnetometer (VSM) and the biocompatibility was evaluated by cell culture and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Furthermore, in vivo histopathological examinations were used to evaluate the potential toxicological effects of Fe₃O₄-HA composites on kidney of SD rats injected intraperitoneally with Fe₃O₄-HA particles. The results showed that magnetic iron oxide particles first replace OH ions of HA, which are parallel to the c axis, and then enter the HA crystal lattice which produces changes in the crystal surface of HA. Chemical bond interaction was observed between PO₄³⁻ groups of HA and iron ions of Fe₃O₄. The saturation magnetization (MS ) of Fe₃O₄-HA composites was 46.36 emu/g obtained from VSM data. Cell culture and MTT assays indicated that HA could affect the growth and proliferation of HEK-293 cells. This Fe₃O₄-HA composite produced no negative effects on cell morphology, viability, and proliferation and exhibited remarkable biocompatibility. Moreover, no inflammatory cell infiltration was observed in kidney histopathology slices. Therefore, this study succeeds to develop a Fe₃O₄-HA composite as a prospective biomagnetic material for future applications. © 2013 Wiley Periodicals, Inc.

3D silicon doped hydroxyapatite scaffolds decorated with Elastin-like Recombinamers for bone regenerative medicine.

Science.gov (United States)

Vila, Mercedes; García, Ana; Girotti, Alessandra; Alonso, Matilde; Rodríguez-Cabello, Jose Carlos; González-Vázquez, Arlyng; Planell, Josep A; Engel, Elisabeth; Buján, Julia; García-Honduvilla, Natalio; Vallet-Regí, María

2016-11-01

The current study reports on the manufacturing by rapid prototyping technique of three-dimensional (3D) scaffolds based on silicon substituted hydroxyapatite with Elastin-like Recombinamers (ELRs) functionalized surfaces. Silicon doped hydroxyapatite (Si-HA), with Ca 10 (PO 4 ) 5.7 (SiO 4 ) 0.3 (OH) 1.7 h 0.3 nominal formula, was surface functionalized with two different types of polymers designed by genetic engineering: ELR-RGD that contain cell attachment specific sequences and ELR-SN A 15/RGD with both hydroxyapatite and cells domains that interact with the inorganic phase and with the cells, respectively. These hybrid materials were subjected to in vitro assays in order to clarify if the ELRs coating improved the well-known biocompatible and bone regeneration properties of calcium phosphates materials. The in vitro tests showed that there was a total and homogeneous colonization of the 3D scaffolds by Bone marrow Mesenchymal Stromal Cells (BMSCs). In addition, the BMSCs were viable and able to proliferate and differentiate into osteoblasts. Bone tissue engineering is an area of increasing interest because its main applications are directly related to the rising life expectancy of the population, which promotes higher rates of several bone pathologies, so innovative strategies are needed for bone tissue regeneration therapies. Here we use the rapid prototyping technology to allow moulding ceramic 3D scaffolds and we use different bio-polymers for the functionalization of their surfaces in order to enhance the biological response. Combining the ceramic material (silicon doped hydroxyapatite, Si-HA) and the Elastin like Recombinamers (ELRs) polymers with the presence of the integrin-mediate adhesion domain alone or in combination with SNA15 peptide that possess high affinity for hydroxyapatite, provided an improved Bone marrow Mesenchymal Stromal Cells (BMSCs) differentiation into osteoblastic linkage. Copyright © 2016 Acta Materialia Inc. Published by Elsevier

Influence of spray parameters on the microstructure and mechanical properties of gas-tunnel plasma sprayed hydroxyapatite coatings

International Nuclear Information System (INIS)

Morks, M.F.; Kobayashi, Akira

2007-01-01

For biomedical applications, hydroxyapatite (HA) coatings were deposited on 304 stainless steel substrate by using a gas tunnel type plasma spraying process. The influences of spraying distances and plasma arc currents on the microstructure, hardness and adhesion properties of HA coatings were investigated. Microstructure observation by SEM showed that HA coatings sprayed at low plasma power have a porous structure and poor hardness. HA coatings sprayed at high plasma power and short spraying distance are characterized by good adhesion and low porosity with dense structure. Hardness increased for HA coatings sprayed at shorter spraying distance and higher plasma power, mainly due to the formation of dense coatings

Composite biocompatible hydroxyapatite-silk fibroin coatings for medical implants obtained by Matrix Assisted Pulsed Laser Evaporation

International Nuclear Information System (INIS)

Miroiu, F.M.; Socol, G.; Visan, A.; Stefan, N.; Craciun, D.; Craciun, V.; Dorcioman, G.; Mihailescu, I.N.; Sima, L.E.; Petrescu, S.M.; Andronie, A.; Stamatin, I.; Moga, S.; Ducu, C.

2010-01-01

The aim of this study was to obtain biomimetic inorganic-organic thin films as coatings for metallic medical implants. These contain hydroxyapatite, the inorganic component of the bony tissues, and a natural biopolymer - silk fibroin - added in view to induce the surface functionalization. Hydroxyapatite (HA), silk fibroin (FIB) and composite HA-FIB films were obtained by Matrix Assisted Pulsed Laser Evaporation (MAPLE) in order to compare their physical and biological performances as coatings on metallic prostheses. We used an excimer laser source (KrF*, λ = 248 nm, τ = 25 ns) operated at 10 Hz repetition rate. Coatings were deposited on quartz, Si and Ti substrates and then subjected to physical (FTIR, XRD, AFM, SEM) analyses, correlated with the results of the cytocompatibility in vitro tests. The hybrid films were synthesized from frozen targets of aqueous suspensions with 3:2 or 3:4 weight ratio of HA:FIB. An appropriate stoichiometric and functional transfer was obtained for 0.4-0.5 J/cm 2 laser fluence. FTIR spectra of FIB and HA-FIB films exhibited distinctive absorption maxima, in specific positions of FIB random coil form: 1540 cm -1 amide II, 1654 cm -1 amide I, 1243 cm -1 amide III, while the peak from 1027 cm -1 appeared only for HA and composite films. Osteosarcoma SaOs2 cells cultured 72 h on FIB and HA-FIB films showed increased viability, good spreading and normal cell morphology. The well-elongated, flattened cells are a sign of an appropriate interaction with the MAPLE FIB and composite HA-FIB coatings.

Composite biocompatible hydroxyapatite-silk fibroin coatings for medical implants obtained by Matrix Assisted Pulsed Laser Evaporation

Energy Technology Data Exchange (ETDEWEB)

Miroiu, F.M., E-mail: marimona.miroiu@inflpr.ro [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Socol, G.; Visan, A.; Stefan, N.; Craciun, D.; Craciun, V.; Dorcioman, G.; Mihailescu, I.N. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Sima, L.E.; Petrescu, S.M. [Institute of Biochemistry, Romanian Academy, 296 Splaiul Independentei, 060031 Bucharest (Romania); Andronie, A.; Stamatin, I. [3Nano-SAE Alternative Energy Sources-University of Bucharest, Faculty of Physics, 409 Atomistilor Street, RO-77125, Magurele-Ilfov (Romania); Moga, S.; Ducu, C. [University of Pitesti, Targul din Vale Str, no. 1, 110040 Pitesti (Romania)

2010-05-25

The aim of this study was to obtain biomimetic inorganic-organic thin films as coatings for metallic medical implants. These contain hydroxyapatite, the inorganic component of the bony tissues, and a natural biopolymer - silk fibroin - added in view to induce the surface functionalization. Hydroxyapatite (HA), silk fibroin (FIB) and composite HA-FIB films were obtained by Matrix Assisted Pulsed Laser Evaporation (MAPLE) in order to compare their physical and biological performances as coatings on metallic prostheses. We used an excimer laser source (KrF*, {lambda} = 248 nm, {tau} = 25 ns) operated at 10 Hz repetition rate. Coatings were deposited on quartz, Si and Ti substrates and then subjected to physical (FTIR, XRD, AFM, SEM) analyses, correlated with the results of the cytocompatibility in vitro tests. The hybrid films were synthesized from frozen targets of aqueous suspensions with 3:2 or 3:4 weight ratio of HA:FIB. An appropriate stoichiometric and functional transfer was obtained for 0.4-0.5 J/cm{sup 2} laser fluence. FTIR spectra of FIB and HA-FIB films exhibited distinctive absorption maxima, in specific positions of FIB random coil form: 1540 cm{sup -1} amide II, 1654 cm{sup -1} amide I, 1243 cm{sup -1} amide III, while the peak from 1027 cm{sup -1} appeared only for HA and composite films. Osteosarcoma SaOs2 cells cultured 72 h on FIB and HA-FIB films showed increased viability, good spreading and normal cell morphology. The well-elongated, flattened cells are a sign of an appropriate interaction with the MAPLE FIB and composite HA-FIB coatings.

Fabrication and Characterization of Collagen-Immobilized Porous PHBV/HA Nano composite Scaffolds for Bone Tissue Engineering

International Nuclear Information System (INIS)

Jin-Young, B.; Zhi-Cai, X.; Giseop, K.; Keun-Byoung, Y.; Soo-Young, P.; Lee, S.P.; Inn-Kyu, K.

2012-01-01

The porous composite scaffolds (PHBV/HA) consisting of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and hydroxyapatite (HA) were fabricated using a hot-press machine and salt-leaching. Collagen (type I) was then immobilized on the surface of the porous PHBV/HA composite scaffolds to improve tissue compatibility. The structure and morphology of the collagen-immobilized composite scaffolds (PHBV/HA/Col) were investigated using a scanning electron microscope (SEM), Fourier transform infrared (FTIR), and electron spectroscopy for chemical analysis (ESCA). The potential of the porous PHBV/HA/Col composite scaffolds for use as a bone scaffold was assessed by an experiment with osteoblast cells (MC3T3-E1) in terms of cell adhesion, proliferation, and differentiation. The results showed that the PHBV/HA/Col composite scaffolds possess better cell adhesion and significantly higher proliferation and differentiation than the PHBV/HA composite scaffolds and the PHBV scaffolds. These results suggest that the PHBV/HA/Col composite scaffolds have a high potential for use in the field of bone regeneration and tissue engineering.

Preliminary biocompatible evaluation of nano-hydroxyapatite/polyamide 66 composite porous membrane

Directory of Open Access Journals (Sweden)

Yili Qu

2010-06-01

Full Text Available Yili Qu1,3, Ping Wang1,3, Yi Man1, Yubao Li2, Yi Zuo2, Jidong Li21State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610064, China; 2Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064, China; 3These authors contributed equally to this workAbstract: Nano-hydroxyapatite/polyamide 66 (nHA/PA66 composite with good bioactivity and osteoconductivity was employed to develop a novel porous membrane with asymmetric structure for guided bone regeneration (GBR. In order to test material cytotoxicity and to investigate surface-dependent responses of bone-forming cells, the morphology, proliferation, and cell cycle of bone marrow stromal cells (BMSCs of rats cultured on the prepared membrane were determined. The polygonal and fusiform shape of BMSCs was observed by scanning electronic microscopy (SEM. The proliferation of BMSCs cultured on nHA/PA66 membrane tested by the MTT method (MTT: [3-{4,5-dimethylthiazol-2yl}-2,5-diphenyl-2H-tetrazoliumbromide] was higher than that of negative control groups for 1 and 4 days’ incubation and had no significant difference for 7 and 11 days’ culture. The results of cell cycle also suggested that the membrane has no negative influence on cell division. The nHA/PA66 membranes were then implanted into subcutaneous sites of nine Sprague Dawley rats. The wounds and implant sites were free from suppuration and necrosis in all periods. All nHA/PA66 membranes were surrounded by a fibrous capsule with decreasing thickness 1 to 8 weeks postoperatively. In conclusion, the results of the in vitro and in vivo studies reveal that nHA/PA66 membrane has excellent biocompatibility and indicate its use in guided tissue regeneration (GTR or GBR.Keywords: hydroxyapatite/polyamide, barrier membrane, biocompatibility, guided bone regeneration

Elaboration of the hydroxyapatite with different precursors and application for the retention of the lead.

Science.gov (United States)

Meski, S; Ziani, S; Khireddine, H; Yataghane, F; Ferguene, N

2011-01-01

Carbonate hydroxyapatite (CHAP) was synthesized from different precursors; synthetic (CaCO3 and Ca(OH)2) and natural (egg shell before and after calcinations at 900 degrees C) under different conditions and characterized by using TG/DTG analysis, X-ray powder diffraction (XRD) method and Fourier transform infrared (FT-IR) spectroscopy techniques. The results of these analyses indicate that the four powders present the same structure of hydroxyapatite. Furthermore the four powders obtained were used for the retention of lead. The results obtained indicated that all powders present high adsorption capacity for lead, but from environmental and economic views, the hydroxyapatite synthesized from eggshell no calcined (HA2) is most advantageous. The influence of different sorption parameters, such as: initial metal concentration, equilibration time, solution pH and sorbent dosage was studied and discussed.

Luminescence variations in europium-doped silicon-substituted hydroxyapatite nanobiophosphor via three different methods

Energy Technology Data Exchange (ETDEWEB)

Thang, Cao Xuan; Pham, Vuong-Hung, E-mail: vuong.phamhung@hust.edu.vn

2015-07-15

Highlights: • Europium doped silicon-substituted hydroxyapatite was synthesized by wet chemical synthesis method. • Morphology of nanoparticles depended on the synthesized method. • Photoluminescence intensity of the sample increases with the increasing of Si substitutions, Eu dopants and thermal annealing. - Abstract: This paper reports the first attempt for the synthesis of europium-doped Si-substituted hydroxyapatite (HA) nanostructure to achieve strong and stable luminescence of nanobiophosphor, particularly, by addition of different Eu dopants, Si substitutions, and application of optimum annealing temperatures of up to 1000 °C. The nanobiophosphor was synthesized by the coprecipitation, microwave, and hydrothermal methods. The nanoparticles demonstrated a nanowire to a spindle-like morphology, which was dependent on the method of synthesis. The photoluminescence (PL) intensity of the sample increases with the increase in Si substitutions and Eu dopants. The luminescent nanoparticles also showed the typical luminescence of Eu{sup 3+} centered at 610 nm, which was more efficient for the annealed Eu-doped Si-HA nanoparticles than for the as-synthesized nanoparticles. Among the different synthesis methods, the hydrothermal method reveals the best light emission represented by high PL intensity and narrow PL spectra. These results suggest the potential application of Eu-doped Si-HA in stable and biocompatible nanophosphors for light emission and nanomedicine.

Synthesis of silicated hydroxyapatite Ca10(PO4)6-x(SiO4)x(OH)2-x

International Nuclear Information System (INIS)

Palard, Mickael; Champion, Eric; Foucaud, Sylvie

2008-01-01

The preparation of silicated hydroxyapatite Ca 10 (PO 4 ) 6-x (SiO 4 ) x (OH) 2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by a heat treatment. X-ray diffraction and Rietveld refinement, Fourier transformed IR (FTIR) spectroscopy, elemental analyses, transmission electron microscopy and thermal analyses were used to characterize the samples. The raw materials were composed of a partially silicated and carbonated apatite and a secondary minor phase containing the excess silicon. Single phase silicated hydroxyapatites, with 0≤x≤1, could be synthesized after a thermal treatment of the raw powders above 700 deg. C. The presence of carbonate groups in the raw apatite played an important role in the incorporation of silicates during heating. From the different results, the mechanisms of formation of SiHA are discussed. - Graphical abstract: The preparation of pure silicated hydroxyapatite Ca 10 (PO 4 ) 6-x (SiO 4 ) x (OH) 2-x powders with controlled silicon content was investigated. The synthesis route included a precipitation in aqueous media. It required an additional high temperature solid-state reaction to fully incorporate the silicon into the apatite crystals

Tricalcium phosphate/hydroxyapatite (TCP-HA) bone scaffold as potential candidate for the formation of tissue engineered bone.

Science.gov (United States)

Sulaiman, Shamsul Bin; Keong, Tan Kok; Cheng, Chen Hui; Saim, Aminuddin Bin; Idrus, Ruszymah Bt Hj

2013-06-01

Various materials have been used as scaffolds to suit different demands in tissue engineering. One of the most important criteria is that the scaffold must be biocompatible. This study was carried out to investigate the potential of HA or TCP/HA scaffold seeded with osteogenic induced sheep marrow cells (SMCs) for bone tissue engineering. HA-SMC and TCP/HA-SMC constructs were induced in the osteogenic medium for three weeks prior to implantation in nude mice. The HA-SMC and TCP/HA-SMC constructs were implanted subcutaneously on the dorsum of nude mice on each side of the midline. These constructs were harvested after 8 wk of implantation. Constructs before and after implantation were analyzed through histological staining, scanning electron microscope (SEM) and gene expression analysis. The HA-SMC constructs demonstrated minimal bone formation. TCP/HA-SMC construct showed bone formation eight weeks after implantation. The bone formation started on the surface of the ceramic and proceeded to the centre of the pores. H&E and Alizarin Red staining demonstrated new bone tissue. Gene expression of collagen type 1 increased significantly for both constructs, but more superior for TCP/HA-SMC. SEM results showed the formation of thick collagen fibers encapsulating TCP/HA-SMC more than HA-SMC. Cells attached to both constructs surface proliferated and secreted collagen fibers. The findings suggest that TCP/HA-SMC constructs with better osteogenic potential compared to HA-SMC constructs can be a potential candidate for the formation of tissue engineered bone.

Structural characteristics of porous hydroxyapatite coating on CaO-SiO{sub 2} system glass

Energy Technology Data Exchange (ETDEWEB)

Zhang Hongquan; Yan Yuhua; Li Shipu [Wuhan Univ. of Technology (China). Biomedical and Engineering Research Center

2001-07-01

Hydroxyapatite(HA) coated CaO-SiO{sub 2} system glass composites were prepared successfully by the hydrothermal coating method at the temperature of 250 to 350 C and at pH of 7 to 9. The microstructure and phase composition were identified by XRD, FT-IR, SEM, EPMA and TEM. It is shown that HA coating possessed a porous gradient construction in the interface; HA coating and glass substrate were tightly bonded by an obvious transition. HA coating had a well-distributed porous construction on the surface layer. The interface structure, phase composition and the stability of HA coated glass composites were related with its forming process. These kinds of structure will benefit to the interface bonging strength and bone bonding strength. (orig.)

Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite.

Science.gov (United States)

Friederichs, Robert J; Chappell, Helen F; Shepherd, David V; Best, Serena M

2015-07-06

Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100 °C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl IR stretching region suggested Zn and silicate co-substitution in ZnSiHA. Zn and silicate insertion into HA was modelled using density functional theory (DFT). Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA. The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site. A combination of experimental chemistry and DFT modelling provided insight into these complex co-substituted calcium phosphates that could find biomedical application as a synthetic bone mineral substitute. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite

Science.gov (United States)

Friederichs, Robert J.; Chappell, Helen F.; Shepherd, David V.; Best, Serena M.

2015-01-01

Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100°C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl IR stretching region suggested Zn and silicate co-substitution in ZnSiHA. Zn and silicate insertion into HA was modelled using density functional theory (DFT). Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA. The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site. A combination of experimental chemistry and DFT modelling provided insight into these complex co-substituted calcium phosphates that could find biomedical application as a synthetic bone mineral substitute. PMID:26040597

In vitro study on the degradation of lithium-doped hydroxyapatite for bone tissue engineering scaffold

Energy Technology Data Exchange (ETDEWEB)

Wang, Yaping; Yang, Xu; Gu, Zhipeng; Qin, Huanhuan [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Li, Li [Department of Oncology, The 452 Hospital of Chinese PLA, Chengdu, Sichuan Province 610021 (China); Liu, Jingwang [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Yu, Xixun, E-mail: yuxixun@163.com [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China)

2016-09-01

Li-doped hydroxyapatite (LiHA) which is prepared through introducing low dose of Li into hydroxyapatite (HA) has been increasingly studied as a bone tissue-engineered scaffold. The degradation properties play a crucial role in the success of long-term implantation of a bone tissue-engineered construct. Herein, the in vitro degradation behaviors of LiHA scaffolds via two approaches were investigated in this study: solution-mediated degradation and osteoblast-mediated degradation. In solution-mediated degradation, after being immersed in simulated body fluid (SBF) for some time, some characteristics of these scaffolds (such as release of ionized lithium and phosphate, pH change, mechanical properties, cytocompatibility and SEM surface characterization) were systematically tested. A similar procedure was also employed to research the degradation behaviors of LiHA scaffolds in osteoblast-mediated degradation. The results suggested that the degradation in SBF and degradation in culture medium with cell existed distinguishing mechanisms. LiHA scaffolds were degraded via a hydrolytic mechanism when they were soaked in SBF. Upon degradation, an apatite precipitation (layer) was formed on the surfaces of scaffolds. While a biological mechanism was presented for the degradation of scaffolds in cell-mediated degradation. Compared with pure HA, LiHA scaffolds had a better effect on the growth of osteoblast cells, meanwhile, the release amount of PO{sub 4}{sup 3−} in a degradation medium indicated that osteoblasts could accelerate the degradation of LiHA due to the more physiological activities of osteoblast. According to the results from compressive strength test, doping Li into HA could enhance the strength of HA. Moreover, the results from MTT assay and SEM observation showed that the degradation products of LiHA scaffolds were beneficial to the proliferation of osteoblasts. The results of this research can provide the theoretical basis for the clinical application of LiHA

Properties and in vivo investigation of nanocrystalline hydroxyapatite obtained by mechanical alloying

Energy Technology Data Exchange (ETDEWEB)

Silva, C.C.; Pinheiro, A.G.; Oliveira, R.S. de; Goes, J.C.; Aranha, N.; Oliveira, L.R. de; Sombra, A.S.B

2004-06-01

Mechanical alloying has been used successfully to produce nanocrystalline powders of hydroxyapatite (HA) using three different procedures. The milled HA was studied by X-ray diffraction, Infrared, Raman scattering spectroscopy and Scanning Electron Microscopy (SEM). We obtained HA with different degrees of crystallinity and time of milling. The grain size analysis through SEM and XRD shows particles with dimensions of 36.9, 14.3 and 35.5 nm (for (R1), (R2) and (R3), respectively) forming bigger units with dimensions given by 117.2, 110.8 and 154.4 nm (for (R1), (R2) and (R3), respectively). The Energy-Dispersive Spectroscopy (EDS) analysis showed that an atomic ratio of Ca/P=1.67, 1.83 and 1.50 for reactions (R1), (R2) and (R3), respectively. These results suggest that the R1 nanocrystalline ceramic is closer to the expected value for the ratio Ca/P for hydroxyapatite, which is 5/3 congruent with 1.67. The bioactivity analysis shows that all the samples implanted into the rabbits can be considered biocompatible, since they had been considered not toxic, had not caused inflammation and reject on the part of the organisms of the animals, during the period of implantation. The samples implanted in rabbits had presented new osseous tissue formation with the presence of osteoblasts cells.

Properties and in vivo investigation of nanocrystalline hydroxyapatite obtained by mechanical alloying

International Nuclear Information System (INIS)

Silva, C.C.; Pinheiro, A.G.; Oliveira, R.S. de; Goes, J.C.; Aranha, N.; Oliveira, L.R. de; Sombra, A.S.B.

2004-01-01

Mechanical alloying has been used successfully to produce nanocrystalline powders of hydroxyapatite (HA) using three different procedures. The milled HA was studied by X-ray diffraction, Infrared, Raman scattering spectroscopy and Scanning Electron Microscopy (SEM). We obtained HA with different degrees of crystallinity and time of milling. The grain size analysis through SEM and XRD shows particles with dimensions of 36.9, 14.3 and 35.5 nm (for (R1), (R2) and (R3), respectively) forming bigger units with dimensions given by 117.2, 110.8 and 154.4 nm (for (R1), (R2) and (R3), respectively). The Energy-Dispersive Spectroscopy (EDS) analysis showed that an atomic ratio of Ca/P=1.67, 1.83 and 1.50 for reactions (R1), (R2) and (R3), respectively. These results suggest that the R1 nanocrystalline ceramic is closer to the expected value for the ratio Ca/P for hydroxyapatite, which is 5/3 congruent with 1.67. The bioactivity analysis shows that all the samples implanted into the rabbits can be considered biocompatible, since they had been considered not toxic, had not caused inflammation and reject on the part of the organisms of the animals, during the period of implantation. The samples implanted in rabbits had presented new osseous tissue formation with the presence of osteoblasts cells

Synthesis and characterization of hydroxyapatite from fish bone waste

Energy Technology Data Exchange (ETDEWEB)

Marliana, Ana, E-mail: na-cwith22@yahoo.co.id; Fitriani, Eka; Ramadhan, Fauzan; Suhandono, Steven; Yuliani, Keti; Windarti, Tri [Chemistry Department, Faculty of Science and Mathematics, Diponegoro University, Indonesia, 50 275 (Indonesia)

2015-12-29

Waste fish bones is a problem stemming from activities in the field of fisheries and it has not been used optimally. Fish bones contain calcium as natural source that used to synthesize hydroxyapatite (HA). In this research, HA synthesized from waste fish bones as local wisdom in Semarang. The goal are to produce HA with cheaper production costs and to reduce the environmental problems caused by waste bones. The novelty of this study was using of local fish bone as a source of calcium and simple method of synthesis. Synthesis process of HA can be done through a maceration process with firing temperatures of 1000°C or followed by a sol-gel method with firing at 550°C. The results are analyzed using FTIR (Fourier Transform Infrared), XRD (X-Ray Diffraction) and SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-Ray). FTIR spectra showed absorption of phosphate and OH group belonging to HA as evidenced by the results of XRD. The average grain size by maceration and synthesized results are not significant different, which is about 69 nm. The ratio of Ca/P of HA by maceration result is 0.89, then increase after continued in the sol-gel process to 1.41. Morphology of HA by maceration results are regular and uniform particle growth, while the morphology of HA after the sol-gel process are irregular and agglomerated.

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

Preparation of silicon-substituted hydroxyapatite coatings on Ti–30Nb–xTa alloys using cyclic electrochemical deposition method

International Nuclear Information System (INIS)

Kim, Eun-Sil; Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

2014-01-01

Silicon-substituted hydroxyapatite coatings on Ti–30Nb–xTa alloys, prepared using a cyclic electrochemical deposition method, have been investigated using a variety of surface analytical experimental methods. The silicon-substituted hydroxyapatite (Si-HA) coatings were prepared by electrolytic deposition in electrolytes containing Ca 2+ , PO 4 3− and SiO 3 2− ions. The deposited layers were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and a wettability test. Phase transformation from (α″ + β) to largely β occurred with increasing Ta content in the Ti –30Nb–xTa alloys, yielding larger grain size. The morphology of the Si-HA coatings was changed by increasing the number of deposition cycles, with the initial plate-like structures changing to mixed rod-like and plate-like shapes, and finally to a rod-like structure. From the ATR-FTIR spectra, Si existed in the form of SiO 4 4− groups in Si-HA coating layer. The lowest aqueous contact angles and best wettability were found for the Si-HA coatings prepared with 30 deposition cycles. - Highlights: • Electrochemically deposited Si-HA coatings on Ti –30Nb–xTa alloys were investigated. • The Si-HA coatings were initially precipitated along the martensitic structure. • The morphology of the Si-HA coating changed with the deposition cycles. • Si existed in the form of SiO 4 4− groups in the Si-HA coating

Bone integration capability of nanopolymorphic crystalline hydroxyapatite coated on titanium implants

OpenAIRE

Ogawa, Takahiro; Yamada,Masahiro; Ueno,; Tsukimura,Naoki; Ikeda,; Nakagawa,; Hori,; Suzuki,

2012-01-01

Masahiro Yamada*, Takeshi Ueno*, Naoki Tsukimura, Takayuki Ikeda, Kaori Nakagawa, Norio Hori, Takeo Suzuki, Takahiro OgawaLaboratory of Bone and Implant Sciences, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA *These authors contributed equally to this workAbstract: The mechanism by which hydroxyapatite (HA)-coated titanium promotes bone–implant integratio...

Comparison of new bone formation, implant integration, and biocompatibility between RGD-hydroxyapatite and pure hydroxyapatite coating for cementless joint prostheses--an experimental study in rabbits.

Science.gov (United States)

Bitschnau, Achim; Alt, Volker; Böhner, Felicitas; Heerich, Katharina Elisabeth; Margesin, Erika; Hartmann, Sonja; Sewing, Andreas; Meyer, Christof; Wenisch, Sabine; Schnettler, Reinhard

2009-01-01

This is the first work to report on additional Arginin-Glycin-Aspartat (RGD) coating on precoated hydroxyapatite (HA) surfaces regarding new bone formation, implant bone contact, and biocompatibility compared to pure HA coating and uncoated stainless K-wires. There were 39 rabbits in total with 6 animals for the RGD-HA and HA group for the 4 week time period and 9 animals for each of the 3 implant groups for the 12 week observation. A 2.0 K-wire either with RGD-HA or with pure HA coating or uncoated was placed into the intramedullary canal of the tibia. After 4 and 12 weeks, the tibiae were harvested and three different areas of the tibia were assessed for quantitative and qualitative histology for new bone formation, direct implant bone contact, and formation of multinucleated giant cells. Both RGD-HA and pure HA coating showed statistically higher new bone formation and implant bone contact after 12 weeks than the uncoated K-wire. There were no significant differences between the RGD-HA and the pure HA coating in new bone formation and direct implant bone contact after 4 and 12 weeks. The number of multinucleated giant did not differ significantly between the RGD-HA and HA group after both time points. Overall, no significant effects of an additional RGD coating on HA surfaces were detected in this model after 12 weeks. (c) 2008 Wiley Periodicals, Inc.

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...

Effects of parameters of sol-gel process on the phase evolution of sol-gel-derived hydroxyapatite

International Nuclear Information System (INIS)

Eshtiagh-Hosseini, Hossein; Housaindokht, Mohammad Reza; Chahkandi, Mohammad

2007-01-01

It has been established that hydroxyapatite powders can be produced using an alkoxide-based sol-gel technique. Nanocrystalline powders of hydroxyapatite (HA) were prepared from Ca(NO 3 ) 2 .4H 2 O and PO(OC 2 H 5 ) 3 as calcium and phosphorus precursors, respectively, using a sol-gel route. For a number of samples, sol of phosphorus was first hydrolyzed for 24 h with distilled water. The sol temperature, aging time and heat treatment temperature on apatite formation were systematically studied. Increasing the aging time affected the reducing of CaO. Also, increasing the mixed sol solution temperature up to 80 deg. C had a positive effect on the disappearance of impurity phases. With the increase of the calcination temperature >600 deg. C, calcium phosphate impurity phases disappeared. Structural evolution during the synthesis of hydroxyapatite is investigated by using infrared (IR) analysis, X-ray diffraction (XRD), thermal behavior (DTA), and elemental analysis of electron microscopy examination (SEM). X-ray diffraction with the aid of Scherrer and Williamson-Hall equations has been used to characterize the distributions of crystallite size and micro-strain of HA powders .The results indicated that mean crystallite size increased and micro-strain decreased significantly with the rise in firing temperature

Mechanical properties of nanodiamond-reinforced hydroxyapatite composite coatings deposited by suspension plasma spraying

Science.gov (United States)

Chen, Xiuyong; Zhang, Botao; Gong, Yongfeng; Zhou, Ping; Li, Hua

2018-05-01

Hydroxyapatite (HA) coatings suffer from poor mechanical properties, which can be enhanced via incorporation of secondary bioinert reinforcement material. Nanodiamond (ND) possesses excellent mechanical properties to play the role as reinforcement for improving the mechanical properties of brittle HA bioceramic coatings. The major persistent challenge yet is the development of proper deposition techniques for fabricating the ND reinforced HA coatings. In this study, we present a novel deposition approach by plasma spraying the mixtures of ND suspension and micron-sized HA powder feedstock. The effect of ND reinforcement on the microstructure and the mechanical properties of the coatings such as hardness, adhesive strength and friction coefficient were examined. The results showed that the ND-reinforced HA coatings display lower porosity, fewer unmelted particles and uniform microstructure, in turn leading to significantly enhanced mechanical properties. The study presented a promising approach to fabricate ND-reinforced HA composite coatings on metal-based medical implants for potential clinical application.

Hydroxyapatites enriched in silicon–Bioceramic materials for biomedical and pharmaceutical applications

Institute of Scientific and Technical Information of China (English)

Katarzyna Szurkowska; Joanna Kolmas

2017-01-01

Hydroxyapatite (Ca10(PO4)6(OH)2, abbreviated as HA) plays a crucial role in implantology, dentistry and bone surgery. Due to its considerable similarity to the inorganic fraction of the mineralized tissues (bones, enamel and dentin), it is used as component in many bone substitutes, coatings of metallic implants and dental materials. Biomaterial engineering often takes advantage of HA capacity for partial ion substitution because the incorporation of different ions in the HA structure leads to materials with improved biological or physico-chemical properties. The objective of the work is to provide an overview of current knowledge about apatite materials substituted with silicon ions. Although the exact mechanism of action of silicon in the bone formation process has not been fully elucidated, research has shown beneficial effects of this element on bone matrix mineralization as well as on collagen type I synthesis and stabilization. The paper gives an account of the functions of silicon in bone tissue and outlines the present state of research on synthetic HA containing silicate ions (Si-HA). Finally, methods of HA production as well as potential and actual applications of HA materials modified with silicon ions are discussed.

A Bone Graft Substitutes Hydroxyapatite Coated Gentamycin (Bonigent) As Drug Delivery System

International Nuclear Information System (INIS)

Rusnah Mustaffa; Fauziah Othman; Asmah Rahmat; Mohd Reusmaazran Yusof; Shaaban Kasim; Narimah Abu Baka; Nasani Nasrul

2014-01-01

Porous hydroxyapatite coated with antibiotic gentamycin for drug delivery system is namely Bonigent. In this product, antibiotic (gentamycin) is coated into the scaffolds HA porous and Would then be released slowly into the bone tissue upon implantation, this way would increase drug penetration, thus avoiding systemic infection, preventing the formation of biofilm and improved healing. When a foreign material (implants or scaffolds of bone graft substitutes) is introduced into the body, there would be normally formation of biofilm that can lead to systemic infection and cause device failure. Surgeon will use antibiotic such as gentamycin to avoid these effects. The purpose of this project is to investigate the feasibility of fabricating a drug delivery system (DDS) that serves dual functions, to combating biofilms and to enhance bone in growths. We also successfully producing a scaffold HA bone graft substitutes incorporated with antibiotic gentamycin to combating bio-film and prevent the failure medical device implant for healthy and human nation. Bone graft substitutes into porous scaffolds suitable for drug delivery; loading the scaffolds with gentamycin; and study release rate in vivo were studied. Porous bone grafts substitutes are coated with antibiotic gentamycin by immerse technique. In order to limit biofilm formation, biomaterials loaded with suitable antibiotics can be used as a preventative measure. The biomaterials hydroxyapatite (HA) is an osteoconductive space filler and is produced locally by Malaysian Nuclear Agency. Porous HA and HA/ TCP has the potential to be used as synthetic bone graft materials because it is bioactive and biocompatible with bone tissues. Development of a product as bone graft substitute (BGS) with special ability of delivering drug (gentamycin) to bone tissue for better and more effective healing process. Characterization of the physical analysis, porosity, surface morphology by Scanning Electron Microscopy Analysis (SEM) and

In vitro and in vivo investigation of bisphosphonate-loaded hydroxyapatite particles for peri-implant bone augmentation.

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Kettenberger, Ulrike; Luginbuehl, Vera; Procter, Philip; Pioletti, Dominique P

2017-07-01

Locally applied bisphosphonates, such as zoledronate, have been shown in several studies to inhibit peri-implant bone resorption and recently to enhance peri-implant bone formation. Studies have also demonstrated positive effects of hydroxyapatite (HA) particles on peri-implant bone regeneration and an enhancement of the anti-resorptive effect of bisphosphonates in the presence of calcium. In the present study, both hydroxyapatite nanoparticles (nHA) and zoledronate were combined to achieve a strong reinforcing effect on peri-implant bone. The nHA-zoledronate combination was first investigated in vitro with a pre-osteoclastic cell assay (RAW 264.7) and then in vivo in a rat model of postmenopausal osteoporosis. The in vitro study confirmed that the inhibitory effect of zoledronate on murine osteoclast precursor cells was enhanced by loading the drug on nHA. For the in vivo investigation, either zoledronate-loaded or pure nHA were integrated in hyaluronic acid hydrogel. The gels were injected in screw holes that had been predrilled in rat femoral condyles before the insertion of miniature screws. Micro-CT-based dynamic histomorphometry and histology revealed an unexpected rapid mineralization of the hydrogel in vivo through formation of granules, which served as scaffold for new bone formation. The delivery of zoledronate-loaded nHA further inhibited a degradation of the mineralized hydrogel as well as a resorption of the peri-implant bone as effectively as unbound zoledronate. Hyaluronic acid with zoledronate-loaded nHA, thanks to its dual effect on inducing a rapid mineralization and preventing resorption, is a promising versatile material for bone repair and augmentation. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

COMPARISON OF REACTIVITY OF SYNTHETIC AND BOVINE HYDROXYAPATITE IN VITRO UNDER DYNAMIC CONDITIONS

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DIANA HORKAVCOVÁ

2014-03-01

Full Text Available Hydroxyapatite materials prepared by two methods: synthetic (HA–S and bovine (HA-B granules were exposed to a longterm in vitro test under dynamic conditions. Testing cells, filled up to one fourth (¼V of their volume with the tested material, were exposed to continuous flow of simulated body fluid (SBF for 56 days. The objective of the experiment was to determine whether reactivity of the biomaterials (hydroxyapatites, prepared by different methods but identical in terms of their chemical and phase composition, in SBF were comparable. Analyses of the solutions proved that both materials were highly reactive from the very beginning of interaction with SBF (significant decrease of Ca2+ and (PO43- concentrations in the leachate. SEM/EDS images have shown that the surface of bovine HA-B was covered with a new hydroxyapatite (HAp phase in the first two weeks of the test while synthetic HA–S was covered after two weeks of the immersion in SBF. At the end of the test, day 56, both materials were completely covered with well developed porous HAp phase in form of nano-plates. A calculation of the rate of HAp formation from the concentration of (PO43- ions in SBF leachates confirmed that all removed ions were consumed for the formation of the HAp phase throughout the entire testing time for bovine HA–B and only during the second half of the testing time for synthetic HA–S.

Does hydroxyapatite coating have no advantage over porous coating in primary total hip arthroplasty? A meta-analysis.

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Chen, Yun-Lin; Lin, Tiao; Liu, An; Shi, Ming-Min; Hu, Bin; Shi, Zhong-Li; Yan, Shi-Gui

2015-01-28

There are some arguments between the use of hydroxyapatite and porous coating. Some studies have shown that there is no difference between these two coatings in total hip arthroplasty (THA), while several other studies have shown that hydroxyapatite has advantages over the porous one. We have collected the studies in Pubmed, MEDLINE, EMBASE, and the Cochrane library from the earliest possible years to present, with the search strategy of "(HA OR hydroxyapatite) AND ((total hip arthroplasty) OR (total hip replacement)) AND (RCT* OR randomiz* OR control* OR compar* OR trial*)". The randomized controlled trials and comparative observation trials that evaluated the clinical and radiographic effects between hydroxyapatite coating and porous coating were included. Our main outcome measurements were Harris hip score (HHS) and survival, while the secondary outcome measurements were osteolysis, radiolucent lines, and polyethylene wear. Twelve RCTs and 9 comparative observation trials were included. Hydroxyapatite coating could improve the HHS (p hydroxyapatite coating had no advantages on survival (p = 0.32), polyethylene wear (p = 0.08), and radiolucent lines (p = 0.78). Hydroxyapatite coating has shown to have an advantage over porous coating. The HHS and survival was duration-dependent-if given the sufficient duration of follow-up, hydroxyapatite coating would be better than porous coating for the survival. The properties of hydroxyapatite and the implant design had influence on thigh pain incidence, femoral osteolysis, and polyethylene wear. Thickness of 50 to 80 μm and purity larger than 90% increased the thigh pain incidence. Anatomic design had less polyethylene wear.

Microstructure and Mechanical Properties of Graphene-Reinforced Titanium Matrix/Nano-Hydroxyapatite Nanocomposites.

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Li, Feng; Jiang, Xiaosong; Shao, Zhenyi; Zhu, Degui; Zhu, Minhao

2018-04-16

Biomaterial composites made of titanium and hydroxyapatite (HA) powder are among the most important biomedicalmaterials due to their good mechanical properties and biocompatibility. In this work, graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites were prepared by vacuum hot-pressing sintering. The microstructure and mechanical properties of graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were systematically investigated. Microstructures of the nanocomposites were examined by X-ray diffraction (XRD), back scattered electron imaging (BSE), scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS), electron probe microanalyzer (EPMA), and transmission electron microscope (TEM). The mechanical properties were determined from microhardness, shear strength, and compressive strength. Results showed that during the high-temperature sintering process, complex chemical reactions occurred, resulting in new phases of nucleation such as Ca₃(PO₄)₂, Ti x P y , and Ti₃O.The new phases, which easily dropped off under the action of external force, could hinder the densification of sintering and increase the brittleness of the nanocomposites. Results demonstrated that graphene had an impact on the microstructure and mechanical properties of the nanocomposites. Based on the mechanical properties and microstructure of the nanocomposites, the strengthening and fracture mechanisms of the graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were analyzed.

Microstructure and Mechanical Properties of Graphene-Reinforced Titanium Matrix/Nano-Hydroxyapatite Nanocomposites

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Feng Li

2018-04-01

Full Text Available Biomaterial composites made of titanium and hydroxyapatite (HA powder are among the most important biomedicalmaterials due to their good mechanical properties and biocompatibility. In this work, graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites were prepared by vacuum hot-pressing sintering. The microstructure and mechanical properties of graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were systematically investigated. Microstructures of the nanocomposites were examined by X-ray diffraction (XRD, back scattered electron imaging (BSE, scanning electron microscope (SEM equipped with energy dispersive spectrometer (EDS, electron probe microanalyzer (EPMA, and transmission electron microscope (TEM. The mechanical properties were determined from microhardness, shear strength, and compressive strength. Results showed that during the high-temperature sintering process, complex chemical reactions occurred, resulting in new phases of nucleation such as Ca3(PO42, TixPy, and Ti3O.The new phases, which easily dropped off under the action of external force, could hinder the densification of sintering and increase the brittleness of the nanocomposites. Results demonstrated that graphene had an impact on the microstructure and mechanical properties of the nanocomposites. Based on the mechanical properties and microstructure of the nanocomposites, the strengthening and fracture mechanisms of the graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were analyzed.

Synthesis of polycaprolactone/nano hydroxyapatite microspheres; Sintese de microesferas de policaprolactona/nanohidroxiapatita

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Sampaio, Greyce Y.H.; Souza, Mairly K. da S.; Melo, Rafaela Q. da C.; Carrodeguas, Raul G.; Fook, Marcus V.L., E-mail: greycesampaio@gmail.com [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil)

2015-07-01

Polycaprolactone(PCL)/nano hydroxyapatite(nHA) microspheres are advantageous material for manufacturing tridimensional scaffolds and formulating drug delivery systems for bone regeneration. The work was aimed to study the effect of processing variables on the properties of PCL/nHA microspheres. nHA was produced by precipitation method and was obtained calcium deficient nanoparticles consisted of nanorods (∼47 nm x ∼8 nm), according to the results of XRD, FTIR and TEM. PCL/nHA microspheres was produced by solid-in-oil-in-water emulsion solvent evaporation method. The variables studied were concentration of PCL (5,7.5 and 10 % w/v), nHA addition (17, 23 and 28.5% m/m) and surface treatment of nHA with stearic acid (AE). PCL/nHA microspheres were characterized by XRD, FTIR, SEM and TGA. The best result was obtained with a PCL concentration of 10% (w/v) and 23 % (m/m) of modified nHA. Solid PCL/nHA particles ranging 30-70 μm and containing 14 % of nHA dispersed in the polymer matrix were obtained, with agglomerates of nHA raging 5 -15 μm. These results suggest the promising use of this material in bone regeneration devices. (author)

Physical characterization of porous hydroxyapatite prepared by slip casting route

International Nuclear Information System (INIS)

Rusnah Mustaffa; Idris Besar; Mohd Reusmaazran Yusof; Che Rohaida Che Hak

2005-01-01

Recent developments have led to an interest in the potential of porous hydroxyapatite (HA) as a synthetic bone graft. The starting material, that is HA powder, was prepared by the precipitation method using calcium hydroxide and ortho-phosporic acid. Through this route, the HA powder was first made into a slip by mixing with binder and then the slip was transferred into a mould. The binder was used as the porosifier where different ratios of HA to binder were studied. The material was then dried in oven followed by burning in furnace and finally the porous product was obtained and ready for characterization after sintering. The paper presents some characterization of porous HA products including chemical composition, density and macrostructure. The pore sizes obtained were in the range 200 mm to 400 mm diameters. From the different HA to binder ratios, variation in apparent densities were observed which is in the range of 2.63 to 2.76 g/cm 3 . The morphology of porous HA was observed by Scanning Electron Microscope (SEM) at 15 KV. The chemical structure and composition were also determined using Fourier Transform Infrared spectroscopy (FTIR) and the SEM EDAX, respectively, and the results will also be discussed. (Author)

Fabrication of interconnected microporous biomaterials with high hydroxyapatite nanoparticle loading

International Nuclear Information System (INIS)

Zhang Wei; Yao Donggang; Zhang Qingwei; Lelkes, Peter I; Zhou, Jack G

2010-01-01

Hydroxyapatite (HA) is known to promote osteogenicity and enhance the mechanical properties of biopolymers. However, incorporating a large amount of HA into a porous biopolymer still remains a challenge. In the present work, a new method was developed to produce interconnected microporous poly(glycolic-co-lactic acid) (PLGA) with high HA nanoparticle loading. First, a ternary blend comprising PLGA/PS (polystyrene)/HA (40/40/20 wt%) was prepared by melt blending under conditions for formation of a co-continuous phase structure. Next, a dynamic annealing stage under small-strain oscillation was applied to the blend to facilitate nanoparticle redistribution. Finally, the PS phase was sacrificially extracted, leaving a porous matrix. The results from different characterizations suggested that the applied small-strain oscillation substantially accelerated the migration of HA nanoparticles during annealing from the PS phase to the PLGA phase; nearly all HA particles were uniformly presented in the PLGA phase after a short period of annealing. After dissolution of the PS phase, a PLGA material with interconnected microporous structure was successfully produced, with a high HA loading above 30 wt%. The mechanisms beneath the experimental observations, particularly on the enhanced particle migration process, were discussed, and strategies for producing highly particle loaded biopolymers with interconnected microporous structures were proposed.

Study of the gamma irradiation effects on the PMMA/HA and PMMA/SW

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Silva, P., E-mail: silva@ivic.v [Instituto Venezolano de Investigaciones Cientificas, Centro de Fisica, Carretera Panamericana Km. 11, Caracas 1020-A (Venezuela, Bolivarian Republic of); Albano, C. [Universidad Central de Venezuela, Facultad de Ingenieria (Venezuela, Bolivarian Republic of); Instituto Venezolano de Investigaciones Cientificas, Centro de Quimica (Venezuela, Bolivarian Republic of); Perera, R. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas 1080-A (Venezuela, Bolivarian Republic of); Dominguez, N. [Instituto Venezolano de Investigaciones Cientificas, Centro de Quimica (Venezuela, Bolivarian Republic of)

2010-03-15

The behavior of the poly(methyl methacrylate) (PMMA) under the action of gamma radiation has been sufficiently studied. In this work, we present results from melt flow index (MFI), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and electron paramagnetic resonance (EPR) of PMMA composites with hydroxyapatite (HA) and seaweed residues (SW) irradiated with gamma rays at 1.08 kGy/h. Composites of PMMA/HA and PMMA/SW with 10%, 20% and 30% of the filler were prepared. The results show an increase in the MFI values with the integral dose of radiation, being consistent with chain-scission reactions. No EPR signal was observed in pure PMMA, while in the composites, the typical EPR signal of the PMMA radicals was observed, which increased with the amount of HA or SW. When comparing the relative intensities of the EPR signals for both types of composites, a slight increase in the concentration of free radicals generated in the sample with SW respect to that of PMMA/HA composite was obtained. A decay of the total free radical concentration was observed as time elapsed.

Electrospinning of calcium carbonate fibers and their conversion to nanocrystalline hydroxyapatite

International Nuclear Information System (INIS)

Holopainen, Jani; Santala, Eero; Heikkilä, Mikko; Ritala, Mikko

2014-01-01

Calcium carbonate (CaCO 3 ) fibers were prepared by electrospinning followed by annealing. Solutions consisting of calcium nitrate tetrahydrate (Ca(NO 3 ) 2 ·4H 2 O) and polyvinylpyrrolidone (PVP) dissolved in ethanol or 2-methoxyethanol were used for the fiber preparation. By varying the precursor concentrations in the electrospinning solutions CaCO 3 fibers with average diameters from 140 to 290 nm were obtained. After calcination the fibers were identified as calcite by X-ray diffraction (XRD). The calcination process was studied in detail with high temperature X-ray diffraction (HTXRD) and thermogravimetric analysis (TGA). The initially weak fiber-to-substrate adhesion was improved by adding a strengthening CaCO 3 layer by spin or dip coating Ca(NO 3 ) 2 /PVP precursor solution on the CaCO 3 fibers followed by annealing of the gel formed inside the fiber layer. The CaCO 3 fibers were converted to nanocrystalline hydroxyapatite (HA) fibers by treatment in a dilute phosphate solution. The resulting hydroxyapatite had a plate-like crystal structure with resemblance to bone mineral. The calcium carbonate and hydroxyapatite fibers are interesting materials for bone scaffolds and bioactive coatings. - Highlights: • Calcium carbonate fibers were prepared by electrospinning. • The electrospun fibers crystallized to calcite upon calcination at 500 °C. • Spin and dip coating methods were used to improve the adhesion of the CaCO 3 fibers. • The CaCO 3 fibers were converted to hydroxyapatite by treatment in phosphate solution. • The hydroxyapatite fibers consisted of plate-like nanocrystals

Beneficial effects of hydroxyapatite on enamel subjected to 30% hydrogen peroxide.

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Jiang, Tao; Ma, Xiao; Wang, Zhejun; Tong, Hua; Hu, Jiming; Wang, Yining

2008-11-01

To evaluate the effect of combination of hydroxyapatite (HA) and hydrogen peroxide (HP) on color, microhardness and morphology of human tooth enamel. Forty-eight human dental blocks were obtained from 12 pairs of premolars and were randomly divided into four groups. Group DW was treated with distilled water, group HP with 30% HP, group HA+DW with HA mixed with distilled water and group HA+HP with HA mixed with 30% HP. Baseline and final color measurements and microhardness test were carried out before and after bleaching experiments. Two specimens from each group were selected for morphological investigation after final tests. The DeltaE of group HP and HA+HP were significantly higher than those of group DW (p=0.000 and p=0.000) and group HA+DW (p=0.000 and p=0.000). The percentage microhardness loss of group HA+HP was significantly lower than that of group HP (p=0.047), but significantly higher than those of group DW (p=0.000) and group HA+DW (p=0.000). The obvious variation of morphology was only observed on enamel surfaces in group HP. This study suggested that combination of HA and HP was effective in tooth whitening. HA could significantly reduce the microhardness loss of enamel caused by 30% HP and keep enamel surface morphology almost unchanged.