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Sample records for calcium phosphate bone

  1. Prediction of the Setting Properties of Calcium Phosphate Bone Cement

    Directory of Open Access Journals (Sweden)

    Seyed Mahmud Rabiee

    2012-01-01

    Full Text Available Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains poly ethylene glycol solution with different concentrations. In this way, prediction of the mechanical properties, setting times, and injectability helps to optimize the calcium phosphate bone cement properties. The objective of this study is development of three different adaptive neurofuzzy inference systems (ANFISs for estimation of compression strength, setting time, and injectability using the data generated based on experimental observations. The input parameters of models are polyethylene glycol percent and liquid/powder ratio. Comparison of the predicted values and measured data indicates that the ANFIS model has an acceptable performance to the estimation of calcium phosphate bone cement properties.

  2. Prediction of the setting properties of calcium phosphate bone cement.

    Science.gov (United States)

    Rabiee, Seyed Mahmud; Baseri, Hamid

    2012-01-01

    Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains poly ethylene glycol solution with different concentrations. In this way, prediction of the mechanical properties, setting times, and injectability helps to optimize the calcium phosphate bone cement properties. The objective of this study is development of three different adaptive neurofuzzy inference systems (ANFISs) for estimation of compression strength, setting time, and injectability using the data generated based on experimental observations. The input parameters of models are polyethylene glycol percent and liquid/powder ratio. Comparison of the predicted values and measured data indicates that the ANFIS model has an acceptable performance to the estimation of calcium phosphate bone cement properties. PMID:22919372

  3. New developments in calcium phosphate bone cements: approaching spinal applications

    OpenAIRE

    Vlad, Maria Daniela

    2009-01-01

    La presente tesis doctoral (i.e., “New developments in calcium phosphate bone cements: approaching spinal applications”) aporta nuevos conocimientos en el campo de los cementos óseos de fosfato de calcio (CPBCs) en relación a su aplicación clínica en el campo de la cirugía vertebral mínimamente invasiva. La hipótesis central de esta investigación fue formulada en los siguientes términos: “Los cementos apatíticos pueden ser (si se optimizan) una alternativa mejor (debido a sus propiedades d...

  4. Solid-state P-31 MR studies of bone mineral and calcium phosphate bone cements

    International Nuclear Information System (INIS)

    Calcium phosphate bone cements have recently been used to promote bone healing and remodeling, but little is known of their bioabsorption. The purpose of this paper to characterize and quantitate bone mineral and calcium phosphate bone cements with the use of solid-state P-31 NMR imaging to establish a model for bioabsorption studies. Pulverized cortical rabbit bone, octacalcium phosphate spherulites, and two synthetic apatite formulations (A and B, Norian, Mountain View, Calif) were evaluated in vitro. A 9.4-T Varian VXR-400S spectrometer operating at 161.9 MHz for P-31 was used to obtain NMR imaging spectra with the magic-angel spinning technique at a sample spin frequency of 6-7.5 kHz, utilizing an external 85% phosphoric acid reference. T1 was determined in a static 90 degrees τ 90 degrees experiment. Quantitation was attempted in mixed samples

  5. Gelation and biocompatibility of injectable alginate-calcium phosphate gels for bone regeneration

    NARCIS (Netherlands)

    Cardoso, D.A.; Beucken, J.J.J.P van den; Both, L.L.; Bender, J.; Jansen, J.A.; Leeuwenburgh, S.C.G.

    2014-01-01

    An emerging approach toward development of injectable, self-setting, and fully biodegradable bone substitutes involves the combination of injectable hydrogel matrices with a dispersed phase consisting of nanosized calcium phosphate particles. Here, novel injectable composites for bone regeneration h

  6. On the development of an apatitic calcium phosphate bone cement

    Indian Academy of Sciences (India)

    Manoj Komath; H K Varma; R Sivakumar

    2000-04-01

    Development of an apatitic calcium phosphate bone cement is reported. 100 Particles of tetracalcium phosphate (TTCP) and dicalcium phosphate dihydrate (DCPD) were mixed in equimolar ratio to form the cement powder. The wetting medium used was distilled water with Na2HPO4 as accelerator to manipulate the setting time. The cement powder, on wetting with the medium, formed a workable putty. The setting times of the putty were measured using a Vicat type apparatus and the compressive strength was determined with a Universal Testing Machine. The nature of the precipitated cement was analyzed through X-ray diffraction (XRD), fourier transform infrared spectrometry (FTIR) and energy dispersive electron microprobe (EDAX). The results showed the phase to be apatitic with a calcium–to–phosphorous ratio close to that of hydroxyapatite. The microstructure analysis using scanning electron microscopy (SEM) showed hydroxyapatite nanocrystallite growth over particulate matrix surface. The structure has an apparent porosity of ∼ 52%. There were no appreciable dimensional or thermal changes during setting. The cement passed the in vitro toxicological screening (cytotoxicity and haemolysis) tests. Optimization of the cement was done by manipulating the accelerator concentration so that the setting time, hardening time and the compressive strength had clinically relevant values.

  7. Injectable bioactive calcium-magnesium phosphate cement for bone regeneration

    International Nuclear Information System (INIS)

    Novel injectable and degradable calcium-magnesium phosphate cement (CMPC) with rapid-setting characteristic was developed by the introduction of magnesium phosphate cement (MPC) into calcium phosphate cement (CPC). The calcium-magnesium phosphate cement prepared under the optimum P/L ratio exhibited good injectability and desired workability. It could set within 10 min at 37 0C in 100% relative humidity and the compressive strength could reach 47 MPa after setting for 48 h, indicating that the prepared cement has relatively high initial mechanical strength. The results of in vitro degradation experiments demonstrated the good degradability of the injectable CMPC, and its degradation rate occurred significantly faster than that of pure CPC in simulated body fluid (SBF) solution. It can be concluded that the novel injectable calcium-magnesium phosphate cement is highly promising for a wide variety of clinical applications, especially for the development of minimally invasive techniques.

  8. External bone remodeling after injectable calcium-phosphate cement in benign bone tumor: two cases in the hand.

    Science.gov (United States)

    Ichihara, S; Vaiss, L; Acciaro, A L; Facca, S; Liverneaux, P

    2015-12-01

    Bone remodeling commonly occurred after fracture and curettage benign bone tumor. A lot of previous articles reported "internal" trabecular bone remodeling. There were no previous clinical reports about "external" cortical bone remodeling. We present here 2 clinical cases of "external" bone remodeling after injectable calcium-phosphate in benign bone tumor in the hand. In two cases of benign bone tumor, we performed complete removal of the tumor and immediate filling of the metacarpal bone with injectable calcium-phosphate cement Arexbone(®) from the mechanical viewpoint. With respect to the shape of the calcium-phosphate, by using an injection-type, calcium-phosphate is adhered uniformly to the bone cortex by injecting, remodeling has been promoted. After 5 and 8years, both cases were no recurrences, and the shape of the metacarpal looked close to the contralateral side. These findings supposed to be concerned with potential self-healing and self-protection mechanism in human body.

  9. Silver-Doped Calcium Phosphate Bone Cements with Antibacterial Properties

    Science.gov (United States)

    Rau, J. V.; Fosca, M.; Graziani, V.; Egorov, A. A.; Zobkov, Yu. V.; Fedotov, A. Yu.; Ortenzi, M.; Caminiti, R.; Baranchikov, A. E.; Komlev, V. S.

    2016-01-01

    Calcium phosphate bone cements (CPCs) with antibacterial properties are demanded for clinical applications. In this study, we demonstrated the use of a relatively simple processing route based on preparation of silver-doped CPCs (CPCs-Ag) through the preparation of solid dispersed active powder phase. Real-time monitoring of structural transformations and kinetics of several CPCs-Ag formulations (Ag = 0 wt %, 0.6 wt % and 1.0 wt %) was performed by the Energy Dispersive X-ray Diffraction technique. The partial conversion of β-tricalcium phosphate (TCP) phase into the dicalcium phosphate dihydrate (DCPD) took place in all the investigated cement systems. In the pristine cement powders, Ag in its metallic form was found, whereas for CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, CaAg(PO3)3 was detected and Ag (met.) was no longer present. The CPC-Ag 0 wt % cement exhibited a compressive strength of 6.5 ± 1.0 MPa, whereas for the doped cements (CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt %) the reduced values of the compressive strength 4.0 ± 1.0 and 1.5 ± 1.0 MPa, respectively, were detected. Silver-ion release from CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, measured by the Atomic Emission Spectroscopy, corresponds to the average values of 25 µg/L and 43 µg/L, respectively, rising a plateau after 15 days. The results of the antibacterial test proved the inhibitory effect towards pathogenic Escherichia coli for both CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, better performances being observed for the cement with a higher Ag-content. PMID:27096874

  10. Osteoregenerative capacities of dicalcium phosphate-rich calcium phosphate bone cement.

    Science.gov (United States)

    Ko, Chia-Ling; Chen, Jian-Chih; Tien, Yin-Chun; Hung, Chun-Cheng; Wang, Jen-Chyan; Chen, Wen-Cheng

    2015-01-01

    Calcium phosphate cement (CPC) is a widely used bone substitute. However, CPC application is limited by poor bioresorption, which is attributed to apatite, the stable product. This study aims to systematically survey the biological performance of dicalcium phosphate (DCP)-rich CPC. DCP-rich CPC exhibited a twofold, surface-modified DCP anhydrous (DCPA)-to-tetracalcium phosphate (TTCP) molar ratio, whereas conventional CPC (c-CPC) showed a onefold, surface unmodified DCPA-to-TTCP molar ratio. Cell adhesion, morphology, viability, and alkaline phosphatase (ALP) activity in the two CPCs were examined with bone cell progenitor D1 cultured in vitro. Microcomputed tomography and histological observation were conducted after CPC implantation in vivo to analyze the residual implant ratio and new bone formation rate. D1 cells cultured on DCP-rich CPC surfaces exhibited higher cell viability, ALP activity, and ALP quantity than c-CPC. Histological evaluation indicated that DCP-rich CPC showed lesser residual implant and higher new bone formation rate than c-CPC. Therefore, DCP-rich CPC can improve bioresorption. The newly developed DCP-rich CPC exhibited potential therapeutic applications for bone reconstruction.

  11. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects

    DEFF Research Database (Denmark)

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S;

    2015-01-01

    The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled with nanocr......The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled...... with nanocrystalline hydroxyapatite (HA-SiO), deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (BCP 60/40) ratio, or particulate autogenous bone (A) for histological and histomorphometric analysis. At 2 weeks, percent filler amongst the test groups (DBBM (35.65%), HA...

  12. Effects of calcium phosphate/chitosan composite on bone healing in rats: calcium phosphate induces osteon formation.

    Science.gov (United States)

    Fernández, Tulio; Olave, Gilberto; Valencia, Carlos H; Arce, Sandra; Quinn, Julian M W; Thouas, George A; Chen, Qi-Zhi

    2014-07-01

    Vascularization of an artificial graft represents one of the most significant challenges facing the field of bone tissue engineering. Over the past decade, strategies to vascularize artificial scaffolds have been intensively evaluated using osteoinductive calcium phosphate (CaP) biomaterials in animal models. In this work, we observed that CaP-based biomaterials implanted into rat calvarial defects showed remarkably accelerated formation and mineralization of new woven bone in defects in the initial stages, at a rate of ∼60 μm/day (0.8 mg/day), which was considerably higher than normal bone growth rates (several μm/day, 0.1 mg/day) in implant-free controls of the same age. Surprisingly, we also observed histological evidence of primary osteon formation, indicated by blood vessels in early-region fibrous tissue, which was encapsulated by lamellar osteocyte structures. These were later fully replaced by compact bone, indicating complete regeneration of calvarial bone. Thus, the CaP biomaterial used here is not only osteoinductive, but vasculogenic, and it may have contributed to the bone regeneration, despite an absence of osteons in normal rat calvaria. Further investigation will involve how this strategy can regulate formation of vascularized cortical bone such as by control of degradation rate, and use of models of long, dense bones, to more closely approximate repair of human cortical bone. PMID:24460696

  13. Calcium phosphate cement delivering zoledronate decreases bone turnover rate and restores bone architecture in ovariectomized rats.

    Science.gov (United States)

    Wu, Chang-Chin; Wang, Chen-Chie; Lu, Dai-Hua; Hsu, Li-Ho; Yang, Kai-Chiang; Lin, Feng-Huei

    2012-06-01

    Patients sustaining bony fractures frequently require the application of bone graft substitutes to fill the bone defects. In the meantime, anti-osteoporosis drugs may be added in bone fillers to treat osteoporosis, especially in postmenopausal women and the elderly. The effects of zoledronate-impregnated calcium phosphate cement (ZLN/CPC) on ovariectomized (OVX) rats were evaluated. OVX rats were implanted with ZLN/CPC, containing 0.025 mg ZLN in the greater omentum. Afterward the clinical sign of toxicity was recorded for eight weeks. The rats were sacrificed and blood samples were collected for hematology and serum bone turnover markers analyses. The four limbs of the rats were harvested and micro-computer tomography (micro-CT) scanning and bone ash analyses were performed. No clinical toxicity was observed in the treated rats. Compared to the OVX rats, levels of bone resorption markers (fragments of C-telopeptides of type I collagen) and bone formation markers (alkaline phosphatase and osteocalcin) decreased significantly in the treated rats. Osteopontin, which mediates the anchoring of osteoclasts to the mineral matrix of bones, also decreased significantly. Micro-CT scanning and histologic examinations of the distal femoral metaphyses showed that the cancellous bone architectures were restored, with a concomitant decrease in bone porosity. The bone mineral content in the bone ashes also increased significantly. This study indicates that ZLN-impregnated CPC reduces bone turnover rate and restores bone architecture in OVX rats. CPC may be an appropriate carrier to deliver drugs to treat osteoporosis, and this approach may also reduce rates of post-dosing symptoms for intravenous ZLN delivery.

  14. Calcium phosphate cement delivering zoledronate decreases bone turnover rate and restores bone architecture in ovariectomized rats

    International Nuclear Information System (INIS)

    Patients sustaining bony fractures frequently require the application of bone graft substitutes to fill the bone defects. In the meantime, anti-osteoporosis drugs may be added in bone fillers to treat osteoporosis, especially in postmenopausal women and the elderly. The effects of zoledronate-impregnated calcium phosphate cement (ZLN/CPC) on ovariectomized (OVX) rats were evaluated. OVX rats were implanted with ZLN/CPC, containing 0.025 mg ZLN in the greater omentum. Afterward the clinical sign of toxicity was recorded for eight weeks. The rats were sacrificed and blood samples were collected for hematology and serum bone turnover markers analyses. The four limbs of the rats were harvested and micro-computer tomography (micro-CT) scanning and bone ash analyses were performed. No clinical toxicity was observed in the treated rats. Compared to the OVX rats, levels of bone resorption markers (fragments of C-telopeptides of type I collagen) and bone formation markers (alkaline phosphatase and osteocalcin) decreased significantly in the treated rats. Osteopontin, which mediates the anchoring of osteoclasts to the mineral matrix of bones, also decreased significantly. Micro-CT scanning and histologic examinations of the distal femoral metaphyses showed that the cancellous bone architectures were restored, with a concomitant decrease in bone porosity. The bone mineral content in the bone ashes also increased significantly. This study indicates that ZLN-impregnated CPC reduces bone turnover rate and restores bone architecture in OVX rats. CPC may be an appropriate carrier to deliver drugs to treat osteoporosis, and this approach may also reduce rates of post-dosing symptoms for intravenous ZLN delivery. (paper)

  15. Preparation and Compressive Strength of Calcium Phosphate Bone Cement Containing N, O-carboxymethyl Chitosan

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    N, O-carboxymethyl chitosan ( CMCTS ), a kind of biodegradable organic substance, was added to calcium phosphate bone cement (CPC) to produce a composite more similar in composition to human bone. The compressive strength of the new material was increased by 10 times compared with conventional CPC.

  16. An injectable calcium phosphate cement for the local delivery of paclitaxel to bone

    NARCIS (Netherlands)

    Lopez-Heredia, M.A.; Kamphuis, G.J.; Thune, P.C.; Oner, F.C.; Jansen, J.A.; Walboomers, X.F.

    2011-01-01

    Bone metastases are usually treated by surgical removal, fixation and chemotherapeutic treatment. Bone cement is used to fill the resection voids. The aim of this study was to develop a local drug delivery system using a calcium phosphate cement (CPC) as carrier for chemotherapeutic agents. CPC cons

  17. Ectopic bone formation in bone marrow stem cell seeded calcium phosphate scaffolds as compared to autograft and (cell seeded allograft

    Directory of Open Access Journals (Sweden)

    J O Eniwumide

    2007-08-01

    Full Text Available Improvements to current therapeutic strategies are needed for the treatment of skeletal defects. Bone tissue engineering offers potential advantages to these strategies. In this study, ectopic bone formation in a range of scaffolds was assessed. Vital autograft and devitalised allograft served as controls and the experimental groups comprised autologous bone marrow derived stem cell seeded allograft, biphasic calcium phosphate (BCP and tricalcium phosphate (TCP, respectively. All implants were implanted in the back muscle of adult Dutch milk goats for 12 weeks. Micro-computed tomography (µCT analysis and histomorphometry was performed to evaluate and quantify ectopic bone formation. In good agreement, both µCT and histomorphometric analysis demonstrated a significant increase in bone formation by cell-seeded calcium phosphate scaffolds as compared to the autograft, allograft and cell-seeded allograft implants. An extensive resorption of the autograft, allograft and cell-seeded allograft implants was observed by histology and confirmed by histomorphometry. Cell-seeded TCP implants also showed distinct signs of degradation with histomorphometry and µCT, while the degradation of the cell-seeded BCP implants was negligible. These results indicate that cell-seeded calcium phosphate scaffolds are superior to autograft, allograft or cell-seeded allograft in terms of bone formation at ectopic implantation sites. In addition, the usefulness of µCT for the efficient and non-destructive analysis of mineralised bone and calcium phosphate scaffold was demonstrated.

  18. Investigating calcium polyphosphate addition to a conventional calcium phosphate cement for bone-interfacing applications

    Science.gov (United States)

    Krausher, Jennifer Lynn

    Calcium phosphate cements (CPCs) are of great interest in bone regeneration applications because of their biocompatibility and osteoconductivity, and as delivery vehicles for therapeutics; however, delivery applications have been limited by adverse interactions between therapeutics and the cement setting reaction. Amorphous calcium polyphosphate (CPP) yields a biodegradable material with a demonstrated drug delivery capacity following appropriate processing. The incorporation of drug-loaded CPP into a CPC is under consideration as a method of minimizing adverse interactions and extending drug release. This thesis represents the first investigation into the effects of CPP addition on the properties, setting and antibiotic release profile of a conventional apatitic calcium phosphate cement. As-made, gelled and vancomycin-loaded CPP particulate were added to the powder component of a conventional dicalcium phosphate/tetracalcium phosphate CPC. The setting behaviour, set properties and microstructure of the resulting CPP-CPCs were evaluated with setting time testing (Gilmore needle method), pH testing, mechanical testing, SEM imaging, XRD and FTIR analysis. In vitro degradation and elution behaviour were evaluated by monitoring calcium release (atomic absorbance spectroscopy), mechanical strength and vancomycin release (UV-visual spectrophotometry). CPP addition was found to increase the setting time, reduce the mechanical strength and inhibit the conversion of the CPC starting powders to the set apatitic phase. The most likely mechanism for the observed effect of CPP addition was the adsorption of polyphosphate chains on the particle surfaces, which would inhibit the dissolution of the starting powders and the conversion of apatite precursor phases to apatite, leading to reduced mechanical properties. The detrimental effects of CPP were reduced by limiting the CPP fraction to less than a few weight per cent and increasing the size of the CPP particulate. CPP

  19. Calcium carbonate-calcium phosphate mixed cement compositions for bone reconstruction.

    Science.gov (United States)

    Combes, C; Bareille, R; Rey, C

    2006-11-01

    The feasibility of making calcium carbonate-calcium phosphate (CaCO(3)-CaP) mixed cements, comprising at least 40% (w/w) CaCO(3) in the dry powder ingredients, has been demonstrated. Several original cement compositions were obtained by mixing metastable crystalline CaCO(3) phases with metastable amorphous or crystalline CaP powders in aqueous medium. The cements set within at most 1 h at 37 degrees C in atmosphere saturated with water. The hardened cement is microporous and exhibits weak compressive strength. The setting reaction appeared to be essentially related to the formation of a highly carbonated nanocrystalline apatite phase by reaction of the metastable CaP phase with part or almost all of the metastable CaCO(3) phase. The recrystallization of metastable CaP varieties led to a final cement consisting of a highly carbonated poorly crystalline apatite analogous to bone mineral associated with various amounts of vaterite and/or aragonite. The presence of controlled amounts of CaCO(3) with a higher solubility than that of the apatite formed in the well-developed CaP cements might be of interest to increase resorption rates in biomedical cement and favors its replacement by bone tissue. Cytotoxicity testing revealed excellent cytocompatibility of CaCO(3)-CaP mixed cement compositions.

  20. The progress of early phase bone healing using porous granules produced from calcium phosphate cement

    Directory of Open Access Journals (Sweden)

    Jungbluth P

    2010-05-01

    Full Text Available Abstract Objective Bone grafting is a vital component in many surgical procedures to facilitate the repair of bone defects or fusions. Autologous bone has been the gold standard to date in spite of associated donor-site morbidity and the limited amount of available donor bone. The aim of this study was to investigate the progress of bone regeneration and material degradation of calcium phosphate granules (CPG produced from a calcium phosphate self-setting cement powder compared to the use of autologous bone grafting in the treatment of "critical size defects" on load-bearing long bones of minipigs. Methods A critical size defect in the tibial metaphysis of 16 mini-pigs was filled either with autologous cancellous graft or with micro- and macroporous carbonated, apatic calcium phosphate granules (CPG produced from a calcium phosphate self-setting cement powder. After 6 weeks, the specimens were assessed by X-ray and histological evaluation. The amount of new bone formation was analysed histomorphometrically. Results The semi-quantitative analysis of the radiological results showed a complete osseous bridging of the defect in three cases for the autograft group. In the same group five animals showed a beginning, but still incomplete bridging of the defect, whereas in the CPG group just two animals developed this. All other animals of the CPG group showed only a still discontinuous new bone formation. Altogether, radiologically a better osseous bridging was observed in the autograft group compared to the CPG group. Histomorphometrical analysis after six weeks of healing revealed that the area of new bone was significantly greater in the autograft group concerning the central area of the defect zone (p Conclusions Within the limits of the present study it could be demonstrated that autologous cancellous grafts lead to a significantly better bone regeneration compared to the application of calcium phosphate granules (CPG produced from a calcium

  1. Biomimetic chitosan-calcium phosphate composites with potential applications as bone substitutes: preparation and characterization.

    Science.gov (United States)

    Tanase, Constantin E; Popa, Marcel I; Verestiuc, Liliana

    2012-04-01

    A novel biomimetic technique for obtaining chitosan-calcium phosphates (Cs-CP) scaffolds are presented: calcium phosphates are precipitated from its precursors, CaCl(2) and NaH(2) PO(4) on the Cs matrix, under physiological conditions (human body temperature and body fluid pH; 37°C and pH = 7.2, respectively). Materials composition and structure have been confirmed by various techniques: elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). FTIR and SEM data have shown the arrangement of the calcium phosphates-hydroxyapatite (CP-Hap) onto Cs matrix. In this case the polymer is acting as glue, bonding the calcium phosphates crystals. Behavior in biological simulated fluids (phosphate buffer solution-PBS and PBS-albumin) revealed an important contribution of the chelation between -NH3(+) and Ca(2+) on the scaffold interaction with aqueous mediums; increased quantities of chitosan in composites permit the interaction with human albumin and improve the retention of fluid. The composites are slightly degraded by the lysozyme which facilitates an in vivo degradation control of bone substitutes. Modulus of elasticity is strongly dependent of the ratio chitosan/calcium phosphates and recommends the obtained biomimetic composites as promising materials for a prospective bone application. PMID:22121073

  2. Studies on the mechanisms underlying the transfer of calcium and phosphate from bone to blood

    Energy Technology Data Exchange (ETDEWEB)

    Brommage, Robert J. Jr.

    1978-01-01

    The skeleton is recognized as a crucial organ in the minute-to-minute regulation of the blood levels of calcium and phosphate. The fluxes of calcium and phosphate to and from bone greatly exceed the entry and exit of these ions occurring in the intestine and kidneys. Parathyroid hormone, calcitonin, and 1,25-dihydroxyvitamin D/sub 3/ (1,25-(OH)/sub 2/D/sub 3/ are known to influence the transfer of calcium and phosphate from bone to blood. Three mechanisms have been proposed to explain the hormonal control of the calcium and phosphate effluxes from bone. The concept of a bone membrane maintaining a distinct bone extracellular fluid composition has led to the pump and pH gradient theories. An alternate solubilizer theory proposes that bone cells secrete a substance which increases the solubility of the bone mineral. The bone membrane concept was originally proposed to explain the presence of the apparent anomalously high concentrations of potassium in the bone extracellular fluid. However, the available evidence does not allow an unambiguous decision concerning the presence of a bone membrane. Calvarial lactate production was unaltered by 1,25-(OH)/sub 2/D/sub 3/ treatment and consequently 1,25-(OH)/sub 2/D/sub 3/ does not appear to promote the mobilization of bone mineral through a lactate-mediated pH gradient mechanism. 1,25-(OH)/sub 2/D/sub 3/ did increase the solubility of non-vital bone, clearly demonstrating that the solubilizer mechanism is at least partially responsible for the mobilization of bone mineral and the regulation of blood levels of calcium and phosphate. Vitamin D-deficient female rats fed a 0.2% calcium, 0.4% phosphorous diet and supplemented with daily injections of 0.75 pmole of 1,25-(OH)/sub 2/D/sub 3/ were shown to be capable of bearing young. When the injections of 1,25-(OH)/sub 2/D/sub 3/ were terminated at delivery, the dams and pups showed signs of vitamin D deficiency approximately one week later.

  3. Calcium phosphate holmium-166 ceramic to addition in bone cement: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Donanzam, Blanda A.; Campos, Tarcisio P.R., E-mail: campos@nuclear.ufmg.b [Universidade do Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Nuclear; Dalmazio, Ilza; Valente, Eduardo S., E-mail: id@cdtn.b, E-mail: valente@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Spine metastases are a common and painful complication of cancer. The treatment often consists of bone cement injection (vertebroplasty or kyphoplasty) within vertebral body for vertebrae stabilization, followed by external beam radiation therapy. Recently, researchers introduced the concept of radioactive bone cement for spine tumors therapy. Then, investigations about bioactive and radioactive materials became interesting. In this study, we present the synthesis of calcium phosphate incorporated holmium (CaP-Ho) via sol-gel technique, and its characterization by XRD, FT-IR, NA and SEM. Results showed a multiphasic bioceramic composed mainly of hydroxyapatite, {beta}-tricalcium phosphate, holmium phosphate and traces of calcium pyrophosphate. Furthermore, the nuclide Ho-166 was the major radioisotope produced. Despite that, the radioactive bioceramic CaP-{sup 166}Ho must be investigated in clinical trials to assure its efficacy and safety on spine tumors treatment (author)

  4. Calcium Phosphate Scaffolds Combined with Bone Morphogenetic Proteins or Mesenchymal Stem Cells in Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Han Sun

    2015-01-01

    Full Text Available Objective: The purpose of this study was to review the current status of calcium phosphate (CaP scaffolds combined with bone morphogenetic proteins (BMPs or mesenchymal stem cells (MSCs in the field of bone tissue engineering (BTE. Date Sources: Data cited in this review were obtained primarily from PubMed and Medline in publications from 1979 to 2014, with highly regarded older publications also included. The terms BTE, CaP, BMPs, and MSC were used for the literature search. Study Selection: Reviews focused on relevant aspects and original articles reporting in vitro and/or in vivo results concerning the efficiency of CaP/BMPs or CaP/MSCs composites were retrieved, reviewed, analyzed, and summarized. Results: An ideal BTE product contains three elements: Scaffold, growth factors, and stem cells. CaP-based scaffolds are popular because of their outstanding biocompatibility, bioactivity, and osteoconductivity. However, they lack stiffness and osteoinductivity. To solve this problem, composite scaffolds of CaP with BMPs have been developed. New bone formation by CaP/BMP composites can reach levels similar to those of autografts. CaP scaffolds are compatible with MSCs and CaP/MSC composites exhibit excellent osteogenesis and stiffness. In addition, a CaP/MSC/BMP scaffold can repair bone defects more effectively than an autograft. Conclusions: Novel BTE products possess remarkable osteoconduction and osteoinduction capacities, and exhibit balanced degradation with osteogenesis. Further work should yield safe, viable, and efficient materials for the repair of bone lesions.

  5. Calcium Phosphate Scaffolds Combined with Bone Morphogenetic Proteins or Mesenchymal Stem Cells in Bone Tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    Han Sun; Hui-Lin Yang

    2015-01-01

    Objective:The purpose of this study was to review the current status of calcium phosphate (CaP) scaffolds combined with bone morphogenetic proteins (BMPs) or mesenchymal stem cells (MSCs) in the field of bone tissue engineering (BTE).Date Sources:Data cited in this review were obtained primarily from PubMed and Medline in publications from 1979 to 2014,with highly regarded older publications also included.The terms BTE,CaP,BMPs,and MSC were used for the literature search.Study Selection:Reviews focused on relevant aspects and original articles reporting in vitro and/or in vivo results concerning the efficiency of CaP/BMPs or CaP/MSCs composites were retrieved,reviewed,analyzed,and summarized.Results:An ideal BTE product contains three elements:Scaffold,growth factors,and stem cells.CaP-based scaffolds are popular because of their outstanding biocompatibility,bioactivity,and osteoconductivity.However,they lack stiffness and osteoinductivity.To solve this problem,composite scaffolds of CaP with BMPs have been developed.New bone formation by CaP/BMP composites can reach levels similar to those of autografts.CaP scaffolds are compatible with MSCs and CaP/MSC composites exhibit excellent osteogenesis and stiffness.In addition,a CaP/MSC/BMP scaffold can repair bone defects more effectively than an autograft.Conclusions:Novel BTE products possess remarkable osteoconduction and osteoinduction capacities,and exhibit balanced degradation with osteogenesis.Further work should yield safe,viable,and efficient materials for the repair of bone lesions.

  6. Kinetic study of the setting reaction of a calcium phosphate bone cement.

    Science.gov (United States)

    Fernández, E; Ginebra, M P; Boltong, M G; Driessens, F C; Ginebra, J; De Maeyer, E A; Verbeeck, R M; Planell, J A

    1996-11-01

    The setting reaction of a calcium phosphate bone cement consisting of a mixture of 63.2 wt % alpha-tertiary calcium phosphate (TCP)[alpha-Ca3(PO4)2], 27.7 wt % dicalcium phosphate (DCP) (CaHPO4), and 9.1 wt % of precipitated hydroxyapatite [(PHA) used as seed material] was investigated. The cement samples were prepared at a liquid-to-powder ratio of: L/P = 0.30 ml/g. Bi-distilled water was used as liquid solution. After mixing the powder and liquid, some samples were molded and aged in Ringer's solution at 37 degrees C. At fixed time intervals they were unmolded and then immediately frozen in liquid nitrogen at a temperature of TN = -196 degrees C, lyofilized, and examined by X-ray diffraction as powder samples. The compressive strength versus time was also measured in setting samples of this calcium phosphate bone cement. The crystal entanglement morphology was examined by scanning electron microscopy. The results showed that: 1) alpha-TCP reacted to a calcium-deficient hydroxyapatite (CDHA), Ca9(HPO4)(PO4)5O H, whereas DCP did not react significantly; 2) the reaction was nearly finished within 32 h, during which both the reaction percentage and the compressive strength increased versus time, with a strong correlation between them; and 3) the calcium phosphate bone cement showed in general a structure of groups of interconnected large plates distributed among agglomerations of small crystal plates arranged in very dense packings.

  7. Crystallization at the polymer/calcium-phosphate interface in a sterilized injectable bone substitute IBS.

    Science.gov (United States)

    Schmitt, M; Weiss, P; Bourges, X; Amador del Valle, G; Daculsi, G

    2002-07-01

    Calcium phosphate (CaP) ceramics are the main raw materials used to elaborate blocks or granules for bone substitutes. In this study, injectable bone substitutes (IBS) were developed for applications in orthopedic or dental surgery. Sterile, ready-to-use composite containing CaP granules (biphasic calcium phosphate, BCP) and polymer (hydroxypropylmethylcellulose, HPMC) was prepared. Steam sterilization produced new phenomena at the CaP/polymer interface, resulting in crystal growth. These phenomena may constitute a model for the biomineralization study. Scanning electron microscopy showed that the formed crystallites organize themselves into a three-dimensional structure. Currently, the mechanisms of crystal growth are unknown and have been observed with only one combination of polymer/BCP ceramics after steam sterilization. PMID:12059030

  8. 3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration.

    Science.gov (United States)

    Inzana, Jason A; Olvera, Diana; Fuller, Seth M; Kelly, James P; Graeve, Olivia A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2014-04-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1-2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing.

  9. Calcium Phosphate Biomaterials: An Update

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Current calcium phosphate (CaP) biomaterials for bone repair, substitution, augmentation and regeneration include hydroxyapatite ( HA ) from synthetic or biologic origin, beta-tricalcium phosphate ( β-TCP ) , biphasic calcium phosphate (BCP), and are available as granules, porous blocks, components of composites (CaP/polymer) cements, and as coatings on orthopedic and dental implants. Experimental calcium phosphate biomaterials include CO3- and F-substituted apatites, Mg-and Zn-substituted β-TCP, calcium phosphate glasses. This paper is a brief review of the different types of CaP biomaterials and their properties such as bioactivity, osteoconductivity, osteoinductivity.

  10. Designing calcium phosphate-based bifunctional nanocapsules with bone-targeting properties

    Energy Technology Data Exchange (ETDEWEB)

    Khung, Yit-Lung; Bastari, Kelsen; Cho, Xing Ling; Yee, Wu Aik; Loo, Say Chye Joachim, E-mail: joachimloo@ntu.edu.sg [Nanyang Technological University, School of Materials Science and Engineering (Singapore)

    2012-06-15

    Using sodium dodecyl sulphate micelles as template, hollow-cored calcium phosphate nanocapsules were produced. The surfaces of the nanocapsule were subsequently silanised by a polyethylene glycol (PEG)-based silane with an N-hydroxysuccinimide ester end groups which permits for further attachment with bisphosphonates (BP). Characterisations of these nanocapsules were investigated using Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy, Fourier Transform Infra-Red Spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Dynamic Light Scattering. To further validate the bone-targeting potential, dentine discs were incubated with these functionalised nanocapsules. FESEM analysis showed that these surface-modified nanocapsules would bind strongly to dentine surfaces compared to non-functionalised nanocapsules. We envisage that respective components would give this construct a bifunctional attribute, whereby (1) the shell of the calcium phosphate nanocapsule would serve as biocompatible coating aiding in gradual osteoconduction, while (2) surface BP moieties, acting as targeting ligands, would provide the bone-targeting potential of these calcium phosphate nanocapsules.

  11. In vitro biocompatibility of chitosan/hyaluronic acid-containing calcium phosphate bone cements.

    Science.gov (United States)

    Hesaraki, Saeed; Nezafati, Nader

    2014-08-01

    The need for bone repair has increased as the population ages. In this research, calcium phosphate cements, with and without chitosan (CS) and hyaluronic acid (HA), were synthesized. The composition and morphological properties of cements were evaluated by X-ray diffraction and scanning electron microscopy. The acellular in vitro bioactivity revealed that different apatite morphologies were formed on the surfaces of cements after soaking in simulated body fluid. The in vitro osteoblastic cell biocompatibility of in situ forming cements was evaluated and compared with those of conventional calcium phosphate cements (CPCs). The viability and growth rate of the cells were similar for all CPCs, but better alkaline phosphatase activity was observed for CPC with CS and HA. Calcium phosphate cements supported attachment of osteoblastic cells on their surfaces. Spindle-shaped osteoblasts with developed cytoplasmic membrane were found on the surfaces of cement samples after 7 days of culture. These results reveal the potential of the CPC-CS/HA composites to be used in bone tissue engineering. PMID:24399509

  12. Early resorption of an artificial bone graft made of calcium phosphate for cranioplasty: case report

    Directory of Open Access Journals (Sweden)

    Monaco BA

    2013-11-01

    Full Text Available Bernardo Assumpção de Monaco, Erich Talamoni Fonoff, Manoel Jacobsen TeixeiraDivision of Functional Neurosurgery, Department of Neurology, Hospital das Clinicas, University of São Paulo Medical School, São Paulo, BrazilAbstract: The treatment of uncomplicated osteoma consists of an en bloc resection, or curettage, of the tumor, followed by cranioplasty. Here, we present a case report of a patient treated for a parietal osteoma, followed by a calcium phosphate cranioplasty, with early resorption after 3 months, which was presented by a sinking flap above the resection area. This case suggests that synthetic cranioplasty should be preferred, even in small skull-gap areas.Keywords: cranioplasty, bone cement, osteoma, calcium phosphate, resorption

  13. An experimental approach to the study of the rheology behaviour of synthetic bone calcium phosphate cements

    Energy Technology Data Exchange (ETDEWEB)

    Friberg, J.; Fernandez, E.; Sarda, S.; Nilsson, M.; Ginebra, M.P.; Planell, J.A. [Universidad Politecnica de Catalunya, Barcelona (Spain). Dept. of Materials Science and Metallurgical Engineering; Martinez, S. [Barcelona Univ. (Spain). Mineralogia i Recursos Minerals

    2001-07-01

    Calcium phosphate cements were developed to fit surgical needs in biomedical fields such as odontology or traumatology. Nowadays, a broad field of new applications have been found for this kind of materials. Drug delivery systems, tissue-engineering scaffolds and osteoporotic bone filling applications are some of the new fields that are being benefited with these materials. Looking at both, commercial and new experimental calcium phosphate cements it is found that {alpha}-tricalcium phosphate is the main reactive powder responsible for the setting and the hardening of the cement. Thus, it is important to know how {alpha}-tricalcium phosphate affects injectability of these cements. The aim of this study was to investigate the rheological behaviour of {alpha}-tricalcium phosphate slurries in order to know how the cement injectability should be modified. Factors such as liquid to powder ratio, particle size of the main reactive powder and the addition of dispersants have been considered. The results showed that viscosity decreased when particle size of reactant was increased and when liquid to powder ratio was increased. It was also found that a minimum of viscosity exists at an optimum value of the weight percentage of dispersant. (orig.)

  14. Bone morphogenetic protein Smads signaling in mesenchymal stem cells affected by osteoinductive calcium phosphate ceramics.

    Science.gov (United States)

    Tang, Zhurong; Wang, Zhe; Qing, Fangzhu; Ni, Yilu; Fan, Yujiang; Tan, Yanfei; Zhang, Xingdong

    2015-03-01

    Porous calcium phosphate ceramics (CaP ceramics) could induce ectopic bone formation which was regulated by various signal molecules. In this work, bone marrow mesenchymal stem cells (MSCs) were cultured on the surface of osteoinductive hydroxyapatite (HA) and biphasic calcium phosphate (BCP) ceramics in comparison with control (culture plate) for up to 14 days to detect the signal molecules which might be affected by the CaP ceramics. Without adding osteogenic factors, MSCs cultured on HA and BCP both expressed higher Runx2, Osterix, collagen type I, osteopontin, bone sialoprotein, and osteocalcin at various stages compared with control, thus confirmed the osteoblastic differentiation of MSCs. Later study demonstrated the messenger RNA level of bone morphogenetic protein 2 (BMP2) and BMP4 were also significantly enhanced by HA and BCP. Furthermore, Smad1, 4, 5, and Dlx5, the main molecules in the BMP/Smads signaling pathway, were upregulated by HA and BCP. Moreover, the higher expression of Smads and BMP2, 4 in BCP over HA, corresponded to the better performance of BCP in stimulating in vitro osteoblastic differentiation of MSCs. This was in accordance with the better osteoinductivity of BCP over HA in vivo. Altogether, these results implied that the CaP ceramics may initiate the osteoblastic differentiation of MSCs by influencing the expression of molecules in BMP/Smads pathway.

  15. Inflammatory response and bone healing capacity of two porous calcium phosphate ceramics in critical size cortical bone defects.

    Science.gov (United States)

    Chatterjea, Anindita; van der Stok, Johan; Danoux, Charlène B; Yuan, Huipin; Habibovic, Pamela; van Blitterswijk, Clemens A; Weinans, Harrie; de Boer, Jan

    2014-05-01

    In the present study, two open porous calcium phosphate ceramics, β-tricalcium phosphate (β-TCP), and hydroxyapatite (HA) were compared in a critical-sized femoral defect in rats. Previous comparisons of these two ceramics showed significantly greater osteoinductive potential of β-TCP upon intramuscular implantation and a better performance in a spinal fusion model in dogs. Results of the current study also showed significantly more bone formation in defects grafted with β-TCP compared to HA; however, both the ceramics were not capable of increasing bone formation to such extend that it bridges the defect. Furthermore, a more pronounced degradation of β-TCP was observed as compared to HA. Progression of inflammation and initiation of new bone formation were assessed for both materials at multiple time points by histological and fluorochrome-based analyses. Until 12 days postimplantation, a strong inflammatory response in absence of new bone formation was observed in both ceramics, without obvious differences between the two materials. Four weeks postimplantation, signs of new bone formation were found in both β-TCP and HA. At 6 weeks, inflammation had subsided in both ceramics while bone deposition continued. In conclusion, the two ceramics differed in the amount of bone formed after 8 weeks of implantation, whereas no differences were found in the duration of the inflammatory phase after implantation or initiation of new bone formation.

  16. VEGF incorporated into calcium phosphate ceramics promotes vascularisation and bone formation in vivo

    Directory of Open Access Journals (Sweden)

    E Wernike

    2010-02-01

    Full Text Available Bone formation and osseointegration of biomaterials are dependent on angiogenesis and vascularization. Angiogenic growth factors such as vascular endothelial growth factor (VEGF were shown to promote biomaterial vascularization and enhance bone formation. However, high local concentrations of VEGF induce the formation of malformed, nonfunctional vessels. We hypothesized that a continuous delivery of low concentrations of VEGF from calcium phosphate ceramics may increase the efficacy of VEGF administration.VEGF was co-precipitated onto biphasic calcium phosphate (BCP ceramics to achieve a sustained release of the growth factor. The co-precipitation efficacy and the release kinetics of the protein were investigated in vitro. For in vivo investigations BCP ceramics were implanted into critical size cranial defects in Balb/c mice. Angiogenesis and microvascularization were investigated over 28 days by means of intravital microscopy. The formation of new bone was determined histomorphometrically. Co-precipitation reduced the burst release of VEGF. Furthermore, a sustained, cell-mediated release of low concentrations of VEGF from BCP ceramics was mediated by resorbing osteoclasts. In vivo, sustained delivery of VEGF achieved by protein co-precipitation promoted biomaterial vascularization, osseointegration, and bone formation. Short-term release of VEGF following superficial adsorption resulted in a temporally restricted promotion of angiogenesis and did not enhance bone formation. The release kinetics of VEGF appears to be an important factor in the promotion of biomaterial vascularization and bone formation. Sustained release of VEGF increased the efficacy of VEGF delivery demonstrating that a prolonged bioavailability of low concentrations of VEGF is beneficial for bone regeneration.

  17. Gelation and biocompatibility of injectable alginate-calcium phosphate gels for bone regeneration.

    Science.gov (United States)

    Cardoso, D Alves; van den Beucken, J J J P; Both, L L H; Bender, J; Jansen, J A; Leeuwenburgh, S C G

    2014-03-01

    An emerging approach toward development of injectable, self-setting, and fully biodegradable bone substitutes involves the combination of injectable hydrogel matrices with a dispersed phase consisting of nanosized calcium phosphate particles. Here, novel injectable composites for bone regeneration have been developed based on the combination of ultrapure alginate as the matrix phase, crystalline CaP [monetite and poorly crystalline hydroxyapatite (HA)] powders as both a dispersed mineral phase and a source of calcium for cross-linking alginate, glucono-delta-lactone (GDL) as acidifier and glycerol as both plasticizer and temporary sequestrant. The composites were maximized with respect to CaP content to obtain the highest amount of osteoconductive filler. The viscoelastic and physicochemical properties of the precursor compounds and composites were analyzed using rheometry, elemental analysis (for calcium release and uptake), acidity [by measuring pH in simulated body fluid (SBF)], general biocompatibility (subcutaneous implantation in rabbits), and osteocompatibility (implantation in femoral condyle bone defect of rabbits). The gelation of the resulting composites could be controlled from seconds to tens of minutes by varying the solubility of the CaP phase (HA vs. monetite) or amount of GDL. All composites mineralized extensively in SBF for up to 11 days. In vivo, the composites also disintegrated upon implantation in subcutaneous or bone tissue, leaving behind less degradable but osteoconductive CaP particles. Although the composites need to be optimized with respect to the available amount of calcium for cross-linking of alginate, the beneficial bone response as observed in the in vivo studies render these gels promising for minimally invasive applications as bone-filling material.

  18. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guangyong [Department of Orthopaedics, Taizhou Hospital of Zhejiang Province, Linhai Zhejiang, 317000 (China); Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Liu, Jianli [Trauma Center, Affiliated Hospital of Hainan Medical University, Haikou, Hainan, 570206 (China); Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China); Li, Fan; Pan, Zongyou; Ni, Xiao; Shen, Yue [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Xu, Huazi, E-mail: spinexu@163.com [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Huang, Qing, E-mail: huangqing@nimte.ac.cn [Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China)

    2014-02-01

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6–12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration. - Highlights: • The mechanical strength and degradation rate of CSMPC composites are discussed. • The CSMPC composites exhibited good bioactivity to form bone-like apatite. • The CSMPC composites also show good biocompatibility.

  19. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications

    International Nuclear Information System (INIS)

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6–12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration. - Highlights: • The mechanical strength and degradation rate of CSMPC composites are discussed. • The CSMPC composites exhibited good bioactivity to form bone-like apatite. • The CSMPC composites also show good biocompatibility

  20. Porous poly(DL-lactic-co-glycolic acid)/calcium phosphate cement composite for reconstruction of bone defects.

    NARCIS (Netherlands)

    Ruhe, P.Q.; Hedberg, E.L.; Padron, N.T.; Spauwen, P.H.M.; Jansen, J.A.; Mikos, A.G.

    2006-01-01

    Calcium phosphate (Ca-P) cements are injectable, self-setting ceramic pastes generally known for their favorable bone response. Ingrowth of bone and subsequent degradation rates can be enhanced by the inclusion of macropores. Initial porosity can be induced by CO(2) foaming during setting of the cem

  1. Biphasic calcium phosphate in periapical surgery

    OpenAIRE

    Suneelkumar, Chinni; Datta, Krithika; Manali R Srinivasan; Kumar, Sampath T

    2008-01-01

    Calcium phosphate ceramics like hydroxyapatite and β -tricalcium phosphate (β -TCP) possess mineral composition that closely resembles that of the bone. They can be good bone substitutes due to their excellent biocompatibility. Biphasic calcium phosphate is a bone substitute which is a mixture of hydroxyapatite and β -tricalcium phosphate in fixed ratios. Studies have demonstrated the osteoconductive potential of this composition. This paper highlights the clinical use of biphasic calcium pho...

  2. Augmentation of femoral neck fracture fixation with an injectable calcium-phosphate bone mineral cement.

    Science.gov (United States)

    Stankewich, C J; Swiontkowski, M F; Tencer, A F; Yetkinler, D N; Poser, R D

    1996-09-01

    The first goal of this study was to determine if augmentation with an injectable, in situ setting, calcium-phosphate cement that is capable of being remodeled and was designed to mimic bone mineral significantly improved the strength and stiffness of fixation in a cadaveric femoral neck fracture model. The second goal was to determine if greater increases in fixation strength were achieved as the bone density of the specimen decreased. Sixteen pairs of fresh cadaveric human femora with a mean age of 70.9 years (SD = 17.2 years) were utilized. The bone density of the femoral neck was measured with dual-energy x-ray absorptiometry. The femoral head was impacted vertically with the femoral shaft fixed in 12 degrees of adduction using a materials testing machine to create a fully displaced fracture. Following fracture, 30% inferior comminution was created in each specimen. One randomly chosen femur from each pair underwent anatomic reduction and fixation with three cannulated cancellous bone screws, 7 mm in diameter, in an inverted triangle configuration. The contralateral femur underwent the same fixation augmented with calcium-phosphate cement. Specimens were preconditioned followed by 1.000 cycles to one body weight (611.6 N) at 0.5 Hz to simulate single-limb stance loading. The stiffness in the first cycle was observed to be significantly greater in cement-augmented specimens compared with unaugmented controls (p bone mineral cement failed at a mean of 4,573 N (SD = 1,243 N); this was significantly greater (p bone density (p = 0.25, R2 = 0.09), was weakly correlated to the volume of cement injected (p = 0.07, R2 = 0.22), and was inversely related to the fixation failure load of the control specimen (p = 0.001, R2 = 0.54). There was a mean relative improvement in fixation strength of 169.6% (SD = 77.5). These findings suggest that calcium-phosphate cement provides initial beneficial augmentation to fixation of femoral neck fractures. PMID:8893773

  3. Injectable Hydrogel Composite Based Gelatin-PEG and Biphasic Calcium Phosphate Nanoparticles for Bone Regeneration

    Science.gov (United States)

    Van, Thuy Duong; Tran, Ngoc Quyen; Nguyen, Dai Hai; Nguyen, Cuu Khoa; Tran, Dai Lam; Nguyen, Phuong Thi

    2016-05-01

    Gelatin hydrogels have recently attracted much attention for tissue regeneration because of their biocompatibility. In this study, we introduce poly-ethylene glycol (PEG)—grafted gelatin containing tyramine moieties which have been utilized for in situ enzyme-mediated hydrogel preparation. The hydrogel can be used to load nanoparticles of biphasic calcium phosphate, a mixture of hydroxyapatite and β-tricalcium phosphate, and forming injectable bio-composites. Proton nuclear magnetic resonance (1H NMR) spectra indicated that tyramine-functionalized polyethylene glycol-nitrophenyl carbonate ester was conjugated to the gelatin. The hydrogel composite was rapidly formed in situ (within a few seconds) in the presence of horseradish peroxidase and hydrogen peroxide. In vitro experiments with bio-mineralization on the hydrogel composite surfaces was well-observed after 2 weeks soaking in simulated body fluid solution. The obtained results indicated that the hydrogel composite could be a potential injectable material for bone regeneration.

  4. Direct 3D powder printing of biphasic calcium phosphate scaffolds for substitution of complex bone defects

    International Nuclear Information System (INIS)

    The 3D printing technique based on cement powders is an excellent method for the fabrication of individual and complex bone substitutes even in the case of large defects. The outstanding bone remodeling capacity of biphasic calcium phosphates (BCPs) containing hydroxyapatite (HA) as well as tricalcium phosphate (TCP) in varying ratios makes the adaption of powder systems resulting in BCP materials to this fabrication technique a desirable aim. This study presents the synthesis and characterization of a novel powder system for the 3D printing process, intended for the production of complexly shaped BCP scaffolds by a hydraulic setting reaction of calcium carbonate and TCP with phosphoric acid. The HA/TCP ratio in the specimens could be tailored by the calcium/phosphate ratio of the starting powder. The scaffolds could be fabricated with a dimensional accuracy of >96.5% and a minimal macro pore size of 300 µm. Independent of the phase composition the printed specimens showed a microporosity of approximately 68%, while the compressive strength strongly depended on the chemical composition and increased with rising TCP content in the scaffolds to a maximum of 1.81 MPa. Post-treatment of the scaffolds with a polylactic-co-glycolic acid-solution enhanced the mechanical properties by a factor of 8. In vitro studies showed that all BCP scaffolds were cytocompatible and enhanced the cell viability as well as the cell proliferation, as compared with pure TCP. Cell proliferation is even better on BCP when compared to HA and cell viability is in a similar range on these materials. (paper)

  5. Direct 3D powder printing of biphasic calcium phosphate scaffolds for substitution of complex bone defects.

    Science.gov (United States)

    Castilho, Miguel; Moseke, Claus; Ewald, Andrea; Gbureck, Uwe; Groll, Jürgen; Pires, Inês; Teßmar, Jörg; Vorndran, Elke

    2014-03-01

    The 3D printing technique based on cement powders is an excellent method for the fabrication of individual and complex bone substitutes even in the case of large defects. The outstanding bone remodeling capacity of biphasic calcium phosphates (BCPs) containing hydroxyapatite (HA) as well as tricalcium phosphate (TCP) in varying ratios makes the adaption of powder systems resulting in BCP materials to this fabrication technique a desirable aim. This study presents the synthesis and characterization of a novel powder system for the 3D printing process, intended for the production of complexly shaped BCP scaffolds by a hydraulic setting reaction of calcium carbonate and TCP with phosphoric acid. The HA/TCP ratio in the specimens could be tailored by the calcium/phosphate ratio of the starting powder. The scaffolds could be fabricated with a dimensional accuracy of >96.5% and a minimal macro pore size of 300 µm. Independent of the phase composition the printed specimens showed a microporosity of approximately 68%, while the compressive strength strongly depended on the chemical composition and increased with rising TCP content in the scaffolds to a maximum of 1.81 MPa. Post-treatment of the scaffolds with a polylactic-co-glycolic acid-solution enhanced the mechanical properties by a factor of 8. In vitro studies showed that all BCP scaffolds were cytocompatible and enhanced the cell viability as well as the cell proliferation, as compared with pure TCP. Cell proliferation is even better on BCP when compared to HA and cell viability is in a similar range on these materials.

  6. Effects of adding resorbable chitosan microspheres to calcium phosphate cements for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Dan [Department of Prosthodontics, Beijing Stomatological Hospital, Capital Medical University, Beijing 100050 (China); Dong, Limin [Beijing Key Lab of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Energy Science Building, Beijing 100084 (China); Wen, Ying [Department of Prosthodontics, Beijing Stomatological Hospital, Capital Medical University, Beijing 100050 (China); Xie, Qiufei, E-mail: xieqiuf@163.com [Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081 (China)

    2015-02-01

    Calcium phosphate cements (CPCs) have been widely used as bone graft substitutes. However, the undesirable osteoinductivity and slow degradability of CPCs greatly hamper their clinical application. The aim of this study was to synthesize a type of injectable, bioactive cement. This was accomplished by incorporating chitosan microspheres into CPC. CPC containing chitosan microspheres was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD showed that the hardened chitosan microsphere/CPC with different proportions of microspheres contained diffraction peaks of hydroxyapatite and chitosan. Compressive strength and dissolution in simulated body fluid were measured. The chitosan microsphere/CPC containing 10% (w/w) chitosan microspheres had a compressive strength of 14.78 ± 0.67 MPa. Cavity defects were created in both femoral condylar regions of New Zealand White rabbits. Chitosan microsphere/CPC (composite group) and α-TCP/CPC (control group) were implanted separately into the bone defects of both femurs. X-ray analysis was performed to observe the filling of these bone defects 3 days after surgery. The extent of bone substitute degradation and new bone formation were evaluated by SEM and histological examination at 8, 16, and 24 weeks after implantation. These results showed far more new bone formation and degradation of the chitosan microsphere/CPC composite in the bone defects. These data indicate that a chitosan microsphere/CPC composite might be considered as a promising injectable material for the generation of new bone tissue. - Highlights: • We synthesized an injectable, bioactive chitosan microsphere/CPC for the first time. • 100–400 μm chitosan microspheres were incorporated into the cement solid phase. • XRD showed the construct contained diffraction peaks of hydroxyapatite and chitosan. • Compressive strength of the composite was about 15 MPa comparable to cancellous bone. • The new construct shows better bone

  7. Effects of adding resorbable chitosan microspheres to calcium phosphate cements for bone regeneration

    International Nuclear Information System (INIS)

    Calcium phosphate cements (CPCs) have been widely used as bone graft substitutes. However, the undesirable osteoinductivity and slow degradability of CPCs greatly hamper their clinical application. The aim of this study was to synthesize a type of injectable, bioactive cement. This was accomplished by incorporating chitosan microspheres into CPC. CPC containing chitosan microspheres was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD showed that the hardened chitosan microsphere/CPC with different proportions of microspheres contained diffraction peaks of hydroxyapatite and chitosan. Compressive strength and dissolution in simulated body fluid were measured. The chitosan microsphere/CPC containing 10% (w/w) chitosan microspheres had a compressive strength of 14.78 ± 0.67 MPa. Cavity defects were created in both femoral condylar regions of New Zealand White rabbits. Chitosan microsphere/CPC (composite group) and α-TCP/CPC (control group) were implanted separately into the bone defects of both femurs. X-ray analysis was performed to observe the filling of these bone defects 3 days after surgery. The extent of bone substitute degradation and new bone formation were evaluated by SEM and histological examination at 8, 16, and 24 weeks after implantation. These results showed far more new bone formation and degradation of the chitosan microsphere/CPC composite in the bone defects. These data indicate that a chitosan microsphere/CPC composite might be considered as a promising injectable material for the generation of new bone tissue. - Highlights: • We synthesized an injectable, bioactive chitosan microsphere/CPC for the first time. • 100–400 μm chitosan microspheres were incorporated into the cement solid phase. • XRD showed the construct contained diffraction peaks of hydroxyapatite and chitosan. • Compressive strength of the composite was about 15 MPa comparable to cancellous bone. • The new construct shows better bone

  8. Preparation and characterization of calcium phosphate ceramics and composites as bone substitutes

    Science.gov (United States)

    Zhang, Xing

    Marine CaCO3 skeletons have tailored architectures created by nature, which give them structural support and other functions. For example, seashells have dense lamellar structures, while coral, cuttlebone and sea urchin spines have interconnected porous structures. In our experiments, seashells, coral and cuttlebone were hydrothermally converted to hydroxyapatite (HAP), and sea urchin spines were converted to Mg-substituted tricalcium phosphate (beta-TCMP), while maintaining their original structures. Partially converted shell samples have mechanical strength, which is close to that of compact human bone. After implantation of converted shell and spine samples in rat femoral defects for 6 weeks, there was newly formed bone growth up to and around the implants. Some new bone was found to migrate through the pores of converted spine samples and grow inward. These results show good bioactivity and osteoconductivity of the implants, indicating the converted shell and spine samples can be used as bone defect fillers. Calcium phosphate powders were prepared through different synthesis methods. Micro-size HAP rods were synthesized by hydrothermal method through a nucleation-growth mechanism. On the other hand, HAP particles, which have good crystallinity, were prepared by wet precipitation with further hydrothermal treatment. beta-TCP or beta-TCMP powders were prepared by a two-step process: wet precipitation of apatitic tricalcium phosphate ('precursor') and calcination of the precursor at 800°C for 3 hours. beta-TCMP or beta-TCP powders were also prepared by solid-state reactions from CaHPO4 and CaCO 3 with/without MgO. Biphasic calcium phosphate, which is mixture of HAP and beta-TCP, can be prepared though mechanical mixing of HAP and beta-TCP powders synthesized as above. Dense beta-TCP and beta-TCMP ceramics can be produced by pressing green bodies at 100MPa and further sintering above 1100°C for 2 hours. beta-TCMP ceramics ˜99.4% relative dense were prepared by

  9. Reactive calcium-phosphate-containing poly(ester-co-ether) methacrylate bone adhesives: chemical, mechanical and biological considerations.

    Science.gov (United States)

    Zhao, Xin; Olsen, Irwin; Li, Haoying; Gellynck, Kris; Buxton, Paul G; Knowles, Jonathan C; Salih, Vehid; Young, Anne M

    2010-03-01

    A poly(propylene glycol-co-lactide) dimethacrylate adhesive with monocalcium phosphate monohydrate (MCPM)/beta-tricalcium phosphate (beta-TCP) fillers in various levels has been investigated. Water sorption by the photo-polymerized materials catalyzed varying filler conversion to dicalcium phosphate (DCP). Polymer modulus was found to be enhanced upon raising total calcium phosphate content. With greater DCP levels, faster release of phosphate and calcium ions and improved buffering of polymer degradation products were observed. This could reduce the likelihood of pH-catalyzed bulk degradation and localized acid production and thereby may prevent adverse biological responses. Bone-like MG-63 cells were found to attach, spread and have normal morphology on both the polymer and composite surfaces. Moreover, composites implanted into chick embryo femurs became closely apposed to the host tissue and did not appear to induce adverse immunological reaction. The above results suggest that the new composite materials hold promise as clinical effective bone adhesives.

  10. Dual mode antibacterial activity of ion substituted calcium phosphate nanocarriers for bone infections

    Directory of Open Access Journals (Sweden)

    Sampath Kumar eT.S.

    2015-05-01

    Full Text Available Nanotechnology has tremendous potential for the management of infectious diseases caused by multi-drug resistant (MDR bacteria, through the development of newer antibacterial materials and efficient modes of antibiotic delivery. Calcium phosphate (CaP bioceramics are commonly used as bone substitutes due to their similarity to bone mineral and are widely researched upon for the treatment of bone infections associated with bone loss. CaPs can be used as local antibiotic delivery agents for bone infections and can be substituted with antibacterial ions in their crystal structure to have a wide spectrum, sustained antibacterial activity even against drug resistant bacteria. In the present work, a dual mode antibiotic delivery system with antibacterial ion substituted calcium deficient hydroxyapatite (CDHA nanoparticles has been developed. Antibacterial ions such as zinc, silver and strontium have been incorporated into CDHA at concentrations of 6 at. %, 0.25-0.75 at. % and 2.5-7.5 at. % respectively. The samples were found to be phase pure, acicular nanoparticles of length 40-50 nm and width 5-6 nm approximately. The loading and release profile of doxycycline, a commonly used antibiotic, was studied from the nanocarriers. The drug release was studied for five days and the release profile was influenced by the ion concentrations. The release of antibacterial ions was studied over a period of 21 days. The ion substituted CDHA samples were tested for antibacterial efficacy on S.aureus and E.coli by MIC/MBC studies and time-kill assay. AgCDHA and ZnCDHA showed high antibacterial activity against both bacteria while SrCDHA was weakly active against S.aureus. Present study shows that the antibiotic release can provide the initial high antibacterial activity and the sustained ion release can provide a long-term antibacterial activity. Such dual mode antibiotic and antibacterial ion release offers an efficient and potent way to treat an incumbent drug

  11. Tissue-engineered calcium phosphate cement in rabbit femoral condylar bone defects

    Institute of Scientific and Technical Information of China (English)

    LIU Chun-rong; MIAO Jun; XIA Qun; HUANG Hong-chao; GONG Chen; YANG Qiang; LI Lan-ying

    2012-01-01

    Background Calcium phosphate cement (CPC) is a favorable bone-graft substitute,with excellent biocompatibility and osteoconductivity.However,its reduced osteoinductive ability may limit the utility of CPC.To increase its osteoinductive potential,this study aimed to prepare tissue-engineered CPC and evaluate its use in the repair of bone defects.The fate of transplanted seed cells in vivo was observed at the same time.Methods Tissue-engineered CPC was prepared by seeding CPC with encapsulated bone mesenchymal stem cells (BMSCs) expressing recombinant human bone morphogenetic protein-2 (rhBMP-2) and green fluorescent protein (GFP).Tissue-engineered CPC and pure CPC were implanted into rabbit femoral condyle bone defects respectively.Twelve weeks later,radiographs,morphological observations,histomorphometrical evaluations,and in vivo tracing were performed.Results The radiographs revealed better absorption and faster new bone formation for tissue-engineered CPC than pure CPC.Morphological and histomorphometrical evaluations indicated that tissue-engineered CPC separated into numerous small blocks,with active absorption and recorstruction noted,whereas the residual CPC area was larger in the group treated with pure CPC.In the tissue-engineered CPC group,in vivo tracing revealed numerous cells expressing both GFP and rhBMP-2 that were distributed in the medullar cavity and on the surface of bony trabeculae.Conclusion Tissue-engineered CPC can effectively repair bone defects,with allogenic seeded cells able to grow and differentiate in vivo after transplantation.

  12. Shear-mediated crystallization from amorphous calcium phosphate to bone apatite.

    Science.gov (United States)

    Niu, Xufeng; Wang, Liyang; Tian, Feng; Wang, Lizhen; Li, Ping; Feng, Qingling; Fan, Yubo

    2016-02-01

    The contribution of fluid shear stress (FSS) on the conversion of amorphous calcium phosphate (ACP) to bone apatite is investigated. The ACP precursors are prepared by using a wet-chemistry method and further exposed to the constant FSS environment with values of 0.5, 1.0, 1.5, and 2.0Pa. At the designated time points, the apatites are characterized by transmission electron microscopy, X-ray diffraction, and inductively coupled plasma-mass spectroscopy. The results show that, the low FSS (≤1.0Pa) has positive effects on the transition of ACP, characterized by the accelerated crystallization velocity and the well-organized calcium-deficient hydroxyapatite (CDHA) structure, whereas the high FSS (>1.0Pa) has negative effects on this conversion process, characterized by the poor CDHA crystal morphologies and the destroyed structures. The bioactivity evaluations further reveal that, compared with the FSS-free group, the CDHA prepared under 1.0Pa FSS for 9h presents the more biocompatible features with pre-osteoblast cells. These results are helpful for understanding the mechanism of apatite deposition in natural bone tissue.

  13. Preparation and osteogenic properties of magnesium calcium phosphate biocement scaffolds for bone regeneration

    International Nuclear Information System (INIS)

    The regenerative treatment of large osseous defects remains a formidable challenge in today. In the present study, we have synthesized biodegradable magnesium calcium phosphate biocement (MCPB) scaffolds with interconnected macroporous structure (100–600 μm), as well as good bioactivity, biocompatibility and proper degradatibility. The results revealed that the porosity increased from 52% to 80% of MCPB scaffolds while the compressive strength decreased from 6.1 MPa to 1.2 MPa. We further assessed the effects of scaffolds on the rabbit femur cavity defect model in vivo by using synchrotron radiation X-ray microCT and microCT imaging, indicating that the MCPB scaffolds underwent gradually degradation and promoted the extensive neo-bone formation

  14. HAp granules encapsulated oxidized alginate-gelatin-biphasic calcium phosphate hydrogel for bone regeneration.

    Science.gov (United States)

    Sarker, Avik; Amirian, Jhaleh; Min, Young Ki; Lee, Byong Taek

    2015-11-01

    Bone repair in the critical size defect zone using 3D hydrogel scaffold is still a challenge in tissue engineering field. A novel type of hydrogel scaffold combining ceramic and polymer materials, therefore, was fabricated to meet this challenge. In this study, oxidized alginate-gelatin-biphasic calcium phosphate (OxAlg-Gel-BCP) and spherical hydroxyapatite (HAp) granules encapsulated OxAlg-Gel-BCP hydrogel complex were fabricated using freeze-drying method. Detailed morphological and material characterizations of OxAlg-Gel-BCP hydrogel (OGB00), 25wt% and 35wt% granules encapsulated hydrogel (OGB25 and OGB35) were carried out for micro-structure, porosity, chemical constituents, and compressive stress analysis. Cell viability, cell attachment, proliferation and differentiation behavior of rat bone marrow-derived stem cell (BMSC) on OGB00, OGB25 and OGB35 scaffolds were confirmed by MTT assay, Live-Dead assay, and confocal imaging in vitro experiments. Finally, OGB00 and OGB25 hydrogel scaffolds were implanted in the critical size defect of rabbit femoral chondyle for 4 and 8 weeks. The micro-CT analysis and histological studies conducted by H&E and Masson's trichrome demonstrated that a significantly higher (***phydrogel than in OxAlg-Gel-BCP complex alone. All results taken together, HAp granules encapsulated OxAlg-Gel-BCP system can be a promising 3D hydrogel scaffold for the healing of a critical bone defect.

  15. Calcium and bones

    Science.gov (United States)

    Bone strength and calcium ... calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in ... your body does not absorb enough calcium, your bones can get weak or will not grow properly. ...

  16. Wollastonite nanofiber–doped self-setting calcium phosphate bioactive cement for bone tissue regeneration

    Directory of Open Access Journals (Sweden)

    Guo H

    2012-07-01

    incorporation of WNFs into CPC improved the biological properties for wnf-CPC. Following the implantation of wnf-CPC into bone defects of rabbits, histological evaluation showed that wnf-CPC enhanced the efficiency of new bone formation in comparison with CPC, indicating excellent biocompatibility and osteogenesis of wnf-CPC. In conclusion, wnf-CPC exhibited promising prospects in bone regeneration.Keywords: calcium phosphate cement, degradability, cell and tissue responses, biocompatibility

  17. Bone Tissue Engineering by Using Calcium Phosphate Glass Scaffolds and the Avidin-Biotin Binding System.

    Science.gov (United States)

    Kim, Min-Chul; Hong, Min-Ho; Lee, Byung-Hyun; Choi, Heon-Jin; Ko, Yeong-Mu; Lee, Yong-Keun

    2015-12-01

    Highly porous and interconnected scaffolds were fabricated using calcium phosphate glass (CPG) for bone tissue engineering. An avidin-biotin binding system was used to improve osteoblast-like cell adhesion to the scaffold. The scaffolds had open macro- and micro-scale pores, and continuous struts without cracks or defects. Scaffolds prepared using a mixture (amorphous and crystalline CPG) were stronger than amorphous group and crystalline group. Cell adhesion assays showed that more cells adhered, with increasing cell seeding efficiency to the avidin-adsorbed scaffolds, and that cell attachment to the highly porous scaffolds significantly differed between avidin-adsorbed scaffolds and other scaffolds. Proliferation was also significantly higher for avidin-adsorbed scaffolds. Osteoblastic differentiation of MG-63 cells was observed at 3 days, and MG-63 cells in direct contact with avidin-adsorbed scaffolds were positive for type I collagen, osteopontin, and alkaline phosphatase gene expression. Osteocalcin expression was observed in the avidin-adsorbed scaffolds at 7 days, indicating that cell differentiation in avidin-adsorbed scaffolds occurred faster than the other scaffolds. Thus, these CPG scaffolds have excellent biological properties suitable for use in bone tissue engineering.

  18. A PLA/calcium phosphate degradable composite material for bone tissue engineering: an in vitro study.

    Science.gov (United States)

    Charles-Harris, Montse; Koch, Martin A; Navarro, Melba; Lacroix, Damien; Engel, Elisabeth; Planell, Josep A

    2008-04-01

    Biodegradable polymers reinforced with an inorganic phase such as calcium phosphate glasses may be a promising approach to fulfil the challenging requirements presented by 3D porous scaffolds for tissue engineering. Scaffolds' success depends mainly on their biological behaviour. This work is aimed to the in vitro study of polylactic acid (PLA)/CaP glass 3D porous constructs for bone regeneration. The scaffolds were elaborated using two different techniques, namely solvent-casting and phase-separation. The effect of scaffolds' micro and macrostructure on the biological response of these scaffolds was assayed. Cell proliferation, differentiation and morphology within the scaffolds were studied. Furthermore, polymer/glass scaffolds were seeded under dynamic conditions in a custom-made perfusion bioreactor. Results indicate that the final architecture of the solvent-cast or phase separated scaffolds have a significant effect on cells' behaviour. Solvent-cast scaffolds seem to be the best candidates for bone tissue engineering. Besides, dynamic seeding yielded a higher seeding efficiency in comparison with the static method. PMID:18266084

  19. Injectable calcium phosphate with hydrogel fibers encapsulating induced pluripotent, dental pulp and bone marrow stem cells for bone repair.

    Science.gov (United States)

    Wang, Lin; Zhang, Chi; Li, Chunyan; Weir, Michael D; Wang, Ping; Reynolds, Mark A; Zhao, Liang; Xu, Hockin H K

    2016-12-01

    Human induced pluripotent stem cell-derived mesenchymal stem cells (hiPSC-MSCs), dental pulp stem cells (hDPSCs) and bone marrow MSCs (hBMSCs) are exciting cell sources in regenerative medicine. However, there has been no report comparing hDPSCs, hBMSCs and hiPSC-MSCs for bone engineering in an injectable calcium phosphate cement (CPC) scaffold. The objectives of this study were to: (1) develop a novel injectable CPC containing hydrogel fibers encapsulating stem cells for bone engineering, and (2) compare cell viability, proliferation and osteogenic differentiation of hDPSCs, hiPSC-MSCs from bone marrow (BM-hiPSC-MSCs) and from foreskin (FS-hiPSC-MSCs), and hBMSCs in CPC for the first time. The results showed that the injection did not harm cell viability. The porosity of injectable CPC was 62%. All four types of cells proliferated and differentiated down the osteogenic lineage inside hydrogel fibers in CPC. hDPSCs, BM-hiPSC-MSCs, and hBMSCs exhibited high alkaline phosphatase, runt-related transcription factor, collagen I, and osteocalcin gene expressions. Cell-synthesized minerals increased with time (p0.1). Mineralization by hDPSCs, BM-hiPSC-MSCs, and hBMSCs inside CPC at 14d was 14-fold that at 1d. FS-hiPSC-MSCs were inferior in osteogenic differentiation compared to the other cells. In conclusion, hDPSCs, BM-hiPSC-MSCs and hBMSCs are similarly and highly promising for bone tissue engineering; however, FS-hiPSC-MSCs were relatively inferior in osteogenesis. The novel injectable CPC with cell-encapsulating hydrogel fibers may enhance bone regeneration in dental, craniofacial and orthopedic applications. PMID:27612810

  20. Induction of bone formation in biphasic calcium phosphate scaffolds by bone morphogenetic protein-2 and primary osteoblasts.

    Science.gov (United States)

    Strobel, L A; Rath, S N; Maier, A K; Beier, J P; Arkudas, A; Greil, P; Horch, R E; Kneser, U

    2014-03-01

    Bone tissue engineering strategies mainly depend on porous scaffold materials. In this study, novel biphasic calcium phosphate (BCP) matrices were generated by 3D-printing. High porosity was achieved by starch consolidation. This study aimed to characterise the porous BCP-scaffold properties and interactions of osteogenic cells and growth factors under in vivo conditions. Five differently treated constructs were implanted subcutaneously in syngeneic rats: plain BCP constructs (group A), constructs pre-treated with BMP-2 (group B; 1.6 µg BMP-2 per scaffold), seeded with primary osteoblasts (OB) (group C), seeded with OB and BMP-2 (group D) and constructs seeded with OB and pre-cultivated in a flow bioreactor for 6 weeks (group E). After 2, 4 and 6 weeks, specimens were explanted and subjected to histological and molecular biological analyses. Explanted scaffolds were invaded by fibrovascular tissue without significant foreign body reactions. Morphometric analysis demonstrated significantly increased bone formation in samples from group D (OB + BMP-2) compared to all other groups. Samples from groups B-E displayed significant mRNA expression of bone-specific genes after 6 weeks. Pre-cultivation in the flow bioreactor (group E) induced bone formation comparable with group B. In this study, differences in bone distribution between samples with BMP-2 or osteoblasts could be observed. In conclusion, combination of osteoblasts and BMP-2 synergistically enhanced bone formation in novel ceramic scaffolds. These results provide the basis for further experiments in orthotopic defect models with a focus on future applications in orthopaedic and reconstructive surgery.

  1. Bone healing response to an injectable calcium phosphate cement with enhanced radiopacity.

    Science.gov (United States)

    Acarturk, Oguz; Lehmicke, Michael; Aberman, Harold; Toms, Derek; Hollinger, Jeffrey O; Fulmer, Mark

    2008-07-01

    The aim of this study was to determine the impact of barium sulfate on remodeling and regeneration in standard tibial defects in rabbits treated with the Norian skeletal repair system (SRS). Two formulations of SRS (with and without barium sulfate) were injected into the medullary canal of the tibia of New Zealand white rabbits. Animals were sacrificed at 6 weeks, 6 months, 1 year, and 2 years. Over the 2-year duration of the study, standard SRS and SRS with barium sulfate appeared to be biocompatible and osteoconductive with no evidence of either inflammation or fibrous tissue around the implant materials or at the bone-material interfaces. This outcome underscores the osteophilic property of the SRS. A difference we observed between the standard SRS and the SRS with barium sulfate was the appearance of acellular material contiguous to the SRS with barium sulfate. Energy dispersive X-ray spectroscopy (EDX) analysis was conducted and confirmed that the acellular material was barium sulfate. Pathological examination of additional tissues including regional lymph nodes revealed neither dissemination of calcium phosphate nor barium sulfate. We concluded that the residual barium sulfate detected by EDX was localized to the intramedullary canal of the tibia. PMID:18098201

  2. Microstructure and Mechanical Properties of Calcium Phosphate Cement/Gelatine Composite Scaffold with Oriented Pore Structure for Bone Tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    QI Xiaopeng; HE Fupo; YE Jiandong

    2012-01-01

    The macroporous calcium phosphate(CPC) cement with oriented pore structure was prepared by freeze casting.SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction.The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede's principle.XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement.To improve the mechanical properties of the CPC scaffold,the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds.After reinforced with gelatine,the compressive strength of CPC/gelatine composite increased to 5.12 MPa,around fifty times greater than that of the unreinforced macroporous CPC scaffold,which was only 0.1 MPa.And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain.SEM examination of the specimens indicated good bonding between the cement and gelatine.Participating the external load by the deformable gelatine,patching the defects of the CPC pores wall,and crack deflection were supposed to be the reinforcement mechanisms.In conclusion,the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this work might be a potential scaffold for bone tissue engineering.

  3. Staphylococcal biofilm formation on the surface of three different calcium phosphate bone grafts: a qualitative and quantitative in vivo analysis.

    Science.gov (United States)

    Furustrand Tafin, Ulrika; Betrisey, Bertrand; Bohner, Marc; Ilchmann, Thomas; Trampuz, Andrej; Clauss, Martin

    2015-03-01

    Differences in physico-chemical characteristics of bone grafts to fill bone defects have been demonstrated to influence in vitro bacterial biofilm formation. Aim of the study was to investigate in vivo staphylococcal biofilm formation on different calcium phosphate bone substitutes. A foreign-body guinea-pig infection model was used. Teflon cages prefilled with β-tricalcium phosphate, calcium-deficient hydroxyapatite, or dicalcium phosphate (DCP) scaffold were implanted subcutaneously. Scaffolds were infected with 2 × 10(3) colony-forming unit of Staphylococcus aureus (two strains) or S. epidermidis and explanted after 3, 24 or 72 h of biofilm formation. Quantitative and qualitative biofilm analysis was performed by sonication followed by viable counts, and microcalorimetry, respectively. Independently of the material, S. aureus formed increasing amounts of biofilm on the surface of all scaffolds over time as determined by both methods. For S. epidermidis, the biofilm amount decreased over time, and no biofilm was detected by microcalorimetry on the DCP scaffolds after 72 h of infection. However, when using a higher S. epidermidis inoculum, increasing amounts of biofilm were formed on all scaffolds as determined by microcalorimetry. No significant variation in staphylococcal in vivo biofilm formation was observed between the different materials tested. This study highlights the importance of in vivo studies, in addition to in vitro studies, when investigating biofilm formation of bone grafts.

  4. Formation of interconnected macropores in apatitic calcium phosphate bone cement with the use of an effervescent additive.

    Science.gov (United States)

    Hesaraki, S; Moztarzadeh, F; Sharifi, D

    2007-10-01

    Calcium phosphate cements (CPCs) can be considered as good candidate for bone tissue engineering because they can be resorbed and take part in the bone remodeling process. Several efforts have been made into improve the resorption rate of the calcium phosphate cement by introducing macropores to the cement matrix. In this investigation a simple and effective method has been presented based on the addition of various amounts of an effervescent agent to the calcium phosphate cement components. The effervescent agent was a mixture of sodium hydrogen carbonate, NaHCO(3) (that was added to the powder phase), and citric acid monohydrate, C(6)H(8)O(7).H(2)O (that was dissolved in the liquid phase). The obtained macroporous samples were characterized by Fourier transform infrared spectrometer, X-ray diffraction, and scanning electron microscopy techniques at 4 h after setting and 3 days after soaking in a special simulated body fluid solution named Hank's balanced salt solution. Mercury intrusion porosimetry was also employed for characterizing the pore volume and pore size distribution in the cement structure. Results showed that the rate of conversion of staring reactant to the apatite phase and the apatite chemistry were significantly changed by using the additive in the cement components. Also both the pore volume and pore size were changed by varying both the amount of effervescent additive and the powder to liquid ratio. PMID:17380498

  5. Perfusion electrodeposition of calcium phosphate on additive manufactured titanium scaffolds for bone engineering.

    Science.gov (United States)

    Chai, Yoke Chin; Truscello, Silvia; Bael, Simon Van; Luyten, Frank P; Vleugels, Jozef; Schrooten, Jan

    2011-05-01

    A perfusion electrodeposition (P-ELD) system was reported to functionalize additive manufactured Ti6Al4V scaffolds with a calcium phosphate (CaP) coating in a controlled and reproducible manner. The effects and interactions of four main process parameters - current density (I), deposition time (t), flow rate (f) and process temperature (T) - on the properties of the CaP coating were investigated. The results showed a direct relation between the parameters and the deposited CaP mass, with a significant effect for t (P=0.001) and t-f interaction (P=0.019). Computational fluid dynamic analysis showed a relatively low electrolyte velocity within the struts and a high velocity in the open areas within the P-ELD chamber, which were not influenced by a change in f. This is beneficial for promoting a controlled CaP deposition and hydrogen gas removal. Optimization studies showed that a minimum t of 6 h was needed to obtain complete coating of the scaffold regardless of I, and the thickness was increased by increasing I and t. Energy-dispersive X-ray and X-ray diffraction analysis confirmed the deposition of highly crystalline synthetic carbonated hydroxyapatite under all conditions (Ca/P ratio=1.41). High cell viability and cell-material interactions were demonstrated by in vitro culture of human periosteum derived cells on coated scaffolds. This study showed that P-ELD provides a technological tool to functionalize complex scaffold structures with a biocompatible CaP layer that has controlled and reproducible physicochemical properties suitable for bone engineering.

  6. Electrospun gelatin/poly(ε-caprolactone) fibrous scaffold modified with calcium phosphate for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Rajzer, Izabella, E-mail: irajzer@ath.bielsko.pl [University of Bielsko-Biala (ATH), Department of Mechanical Engineering Fundamentals, Division of Materials Engineering, Willowa 2 Street, 43-309 Bielsko-Biała (Poland); Menaszek, Elżbieta [Jagiellonian University (UJ), Collegium Medicum, Department of Cytobiology, Medyczna 9 Street, 30-068 Cracow (Poland); Kwiatkowski, Ryszard [University of Bielsko-Biala (ATH), Faculty of Materials and Environmental Sciences, Institute of Textile Engineering and Polymer Materials, Willowa 2 Street, 43-309 Bielsko-Biała (Poland); Planell, Josep A.; Castano, Oscar [Institute for Bioengineering of Catalonia (IBEC), Biomaterials for Regenerative Therapies, Baldiri Reixac 15-21, 08028 Barcelona (Spain); Polytechnic University of Catalonia (UPC), Diagonal 647, 08028 Barcelona (Spain); CIBER-BBN The Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine, Barcelona (Spain)

    2014-11-01

    In this study gelatin (Gel) modified with calcium phosphate nanoparticles (SG5) and polycaprolactone (PCL) were used to prepare a 3D bi-layer scaffold by collecting electrospun PCL and gelatin/SG5 fibers separately in the same collector. The objective of this study was to combine the desired properties of PCL and Gel/SG5 in the same scaffold in order to enhance mineralization, thus improving the ability of the scaffold to bond to the bone tissue. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and the wide angle X-ray diffraction (WAXD) measurements confirmed that SG5 nanoparticles were successfully incorporated into the fibrous gelatin matrix. The composite Gel/SG5/PCL scaffold exhibited more enhanced mechanical properties than individual Gel and Gel/SG5 scaffolds. The presence of SG5 nanoparticles accelerated the nucleation and growth of apatite crystals on the surface of the composite Gel/SG5/PCL scaffold in simulated body fluid (SBF). The osteoblast response in vitro to developed electrospun scaffolds (PCL and Gel/SG5/PCL) was investigated by using normal human primary NHOst cell lines. NHOst cell culture studies showed that higher alkaline phosphatase (ALP) activity and better mineralization were obtained in the case of composite materials than in pure PCL scaffolds. The mechanically strong PCL scaffold served as a skeleton, while the Gel/SG5 fibers facilitated cell spreading and mineralization of the scaffold. - Highlights: • Bi-layer scaffolds were produced by electrospinning method. • The addition of nanoparticles enhanced the bioactivity of scaffold. • Bi-layer scaffold enhanced ALP activity and NHOst cell mineralization.

  7. Rapid prototyped porous titanium coated with calcium phosphate as a scaffold for bone tissue engineering.

    NARCIS (Netherlands)

    Lopez-Heredia, M.A.; Sohier, J.; Gaillard, C.; Quillard, S.; Dorget, M.; Layrolle, P.

    2008-01-01

    High strength porous scaffolds and mesenchymal stem cells are required for bone tissue engineering applications. Porous titanium scaffolds (TiS) with a regular array of interconnected pores of 1000 microm in diameter and a porosity of 50% were produced using a rapid prototyping technique. A calcium

  8. Porous calcium phosphate-poly (lactic-co-glycolic) acid composite bone cement: A viable tunable drug delivery system.

    Science.gov (United States)

    Roy, Abhijit; Jhunjhunwala, Siddharth; Bayer, Emily; Fedorchak, Morgan; Little, Steve R; Kumta, Prashant N

    2016-02-01

    Calcium phosphate based cements (CPCs) are frequently used as bone void fillers for non-load bearing segmental bone defects due to their clinically relevant handling characteristics and ability to promote natural bone growth. Macroporous CPC scaffolds with interconnected pores are preferred for their ability to degrade faster and enable accelerated bone regeneration. Herein, a composite CPC scaffold is developed using newly developed resorbable calcium phosphate cement (ReCaPP) formulation containing degradable microspheres of bio-compatible poly (lactic-co-glycolic acid) (PLGA) serving as porogen. The present study is aimed at characterizing the effect of in-vitro degradation of PLGA microspheres on the physical, chemical and structural characteristics of the composite cements. The porosity measurements results reveal the formation of highly interconnected macroporous scaffolds after degradation of PLGA microspheres. The in-vitro characterizations also suggest that the degradation by products of PLGA reduces the pH of the local environment thereby increasing the dissolution rate of the cement. In addition, the in-vitro vancomycin release from the composite CPC scaffold suggests that the drug association with the composite scaffolds can be tuned to achieve control release kinetics. Further, the study demonstrates control release lasting for longer than 10weeks from the composite cements in which vancomycin is encapsulated in PLGA microspheres. PMID:26652353

  9. Porous calcium phosphate-poly (lactic-co-glycolic) acid composite bone cement: A viable tunable drug delivery system.

    Science.gov (United States)

    Roy, Abhijit; Jhunjhunwala, Siddharth; Bayer, Emily; Fedorchak, Morgan; Little, Steve R; Kumta, Prashant N

    2016-02-01

    Calcium phosphate based cements (CPCs) are frequently used as bone void fillers for non-load bearing segmental bone defects due to their clinically relevant handling characteristics and ability to promote natural bone growth. Macroporous CPC scaffolds with interconnected pores are preferred for their ability to degrade faster and enable accelerated bone regeneration. Herein, a composite CPC scaffold is developed using newly developed resorbable calcium phosphate cement (ReCaPP) formulation containing degradable microspheres of bio-compatible poly (lactic-co-glycolic acid) (PLGA) serving as porogen. The present study is aimed at characterizing the effect of in-vitro degradation of PLGA microspheres on the physical, chemical and structural characteristics of the composite cements. The porosity measurements results reveal the formation of highly interconnected macroporous scaffolds after degradation of PLGA microspheres. The in-vitro characterizations also suggest that the degradation by products of PLGA reduces the pH of the local environment thereby increasing the dissolution rate of the cement. In addition, the in-vitro vancomycin release from the composite CPC scaffold suggests that the drug association with the composite scaffolds can be tuned to achieve control release kinetics. Further, the study demonstrates control release lasting for longer than 10weeks from the composite cements in which vancomycin is encapsulated in PLGA microspheres.

  10. Bone formation induced by strontium modified calcium phosphate cement in critical-size metaphyseal fracture defects in ovariectomized rats.

    Science.gov (United States)

    Thormann, Ulrich; Ray, Seemun; Sommer, Ursula; Elkhassawna, Thaqif; Rehling, Tanja; Hundgeburth, Marvin; Henß, Anja; Rohnke, Marcus; Janek, Jürgen; Lips, Katrin S; Heiss, Christian; Schlewitz, Gudrun; Szalay, Gabor; Schumacher, Matthias; Gelinsky, Michael; Schnettler, Reinhard; Alt, Volker

    2013-11-01

    The first objective was to investigate new bone formation in a critical-size metaphyseal defect in the femur of ovariectomized rats filled with a strontium modified calcium phosphate cement (SrCPC) compared to calcium phosphate cement (CPC) and empty defects. Second, detection of strontium release from the materials as well as calcium and collagen mass distribution in the fracture defect should be targeted by time of flight secondary ion mass spectrometry (TOF-SIMS). 45 female Sprague-Dawley rats were randomly assigned to three different treatment groups: (1) SrCPC (n = 15), (2) CPC (n = 15), and (3) empty defect (n = 15). Bilateral ovariectomy was performed and three months after multi-deficient diet, the left femur of all animals underwent a 4 mm wedge-shaped metaphyseal osteotomy that was internally fixed with a T-shaped plate. The defect was then either filled with SrCPC or CPC or was left empty. After 6 weeks, histomorphometric analysis showed a statistically significant increase in bone formation of SrCPC compared to CPC (p = 0.005) and the empty defect (p = 0.002) in the former fracture defect zone. Furthermore, there was a statistically significant higher bone formation at the tissue-implant interface in the SrCPC group compared to the CPC group (p < 0.0001). These data were confirmed by immunohistochemistry revealing an increase in bone-morphogenic protein 2, osteocalcin and osteoprotegerin expression and a statistically significant higher gene expression of alkaline phosphatase, collagen10a1 and osteocalcin in the SrCPC group compared to CPC. TOF-SIMS analysis showed a high release of Sr from the SrCPC into the interface region in this area compared to CPC suggesting that improved bone formation is attributable to the released Sr from the SrCPC.

  11. Enhanced healing of rabbit segmental radius defects with surface-coated calcium phosphate cement/bone morphogenetic protein-2 scaffolds

    International Nuclear Information System (INIS)

    Large osseous defects remain a difficult clinical problem in orthopedic surgery owing to the limited effective therapeutic options, and bone morphogenetic protein-2 (BMP-2) is useful for its potent osteoinductive properties in bone regeneration. Here we build a strategy to achieve prolonged duration time and help inducting new bone formation by using water-soluble polymers as a protective film. In this study, calcium phosphate cement (CPC) scaffolds were prepared as the matrix and combined with sodium carboxymethyl cellulose (CMC-Na), hydroxypropylmethyl cellulose (HPMC), and polyvinyl alcohol (PVA) respectively to protect from the digestion of rhBMP-2. After being implanted in the mouse thigh muscles, the surface-modified composite scaffolds evidently induced ectopic bone formation. In addition, we further evaluated the in vivo effects of surface-modified scaffolds in a rabbit radius critical defect by radiography, three dimensional micro-computed tomographic (μCT) imaging, synchrotron radiation-based micro-computed tomographic (SRμCT) imaging, histological analysis, and biomechanical measurement. The HPMC-modified CPC scaffold was regarded as the best combination for segmental bone regeneration in rabbit radius. - Highlights: • A simple surface-coating method was used to fabricate composite scaffolds. • Growth factor was protected from rapid depletion via superficial coating. • Significant promotion of bone regeneration was achieved. • HPMC-modification displayed optimal effect of bone regeneration

  12. Enhanced healing of rabbit segmental radius defects with surface-coated calcium phosphate cement/bone morphogenetic protein-2 scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yi; Hou, Juan; Yin, ManLi [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Wang, Jing, E-mail: biomatwj@163.com [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Liu, ChangSheng, E-mail: csliu@sh163.net [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China)

    2014-11-01

    Large osseous defects remain a difficult clinical problem in orthopedic surgery owing to the limited effective therapeutic options, and bone morphogenetic protein-2 (BMP-2) is useful for its potent osteoinductive properties in bone regeneration. Here we build a strategy to achieve prolonged duration time and help inducting new bone formation by using water-soluble polymers as a protective film. In this study, calcium phosphate cement (CPC) scaffolds were prepared as the matrix and combined with sodium carboxymethyl cellulose (CMC-Na), hydroxypropylmethyl cellulose (HPMC), and polyvinyl alcohol (PVA) respectively to protect from the digestion of rhBMP-2. After being implanted in the mouse thigh muscles, the surface-modified composite scaffolds evidently induced ectopic bone formation. In addition, we further evaluated the in vivo effects of surface-modified scaffolds in a rabbit radius critical defect by radiography, three dimensional micro-computed tomographic (μCT) imaging, synchrotron radiation-based micro-computed tomographic (SRμCT) imaging, histological analysis, and biomechanical measurement. The HPMC-modified CPC scaffold was regarded as the best combination for segmental bone regeneration in rabbit radius. - Highlights: • A simple surface-coating method was used to fabricate composite scaffolds. • Growth factor was protected from rapid depletion via superficial coating. • Significant promotion of bone regeneration was achieved. • HPMC-modification displayed optimal effect of bone regeneration.

  13. Application of Calcium Phosphate Materials in Dentistry

    Directory of Open Access Journals (Sweden)

    Jabr S. Al-Sanabani

    2013-01-01

    Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

  14. Bioactive glass incorporation in calcium phosphate cement-based injectable bone substitute for improved in vitro biocompatibility and in vivo bone regeneration.

    Science.gov (United States)

    Sadiasa, Alexander; Sarkar, Swapan Kumar; Franco, Rose Ann; Min, Young Ki; Lee, Byong Taek

    2014-01-01

    In this work, we fabricated injectable bone substitutes modified with the addition of bioactive glass powders synthesized via ultrasonic energy-assisted hydrothermal method to the calcium phosphate-based bone cement to improve its biocompatibility. The injectable bone substitutes was initially composed of a powder component (tetracalcium phosphate, dicalcium phosphate dihydrate and calcium sulfate dehydrate) and a liquid component (citric acid, chitosan and hydroxyl-propyl-methyl-cellulose) upon which various concentrations of bioactive glass were added: 0%, 10%, 20% and 30%. Setting time and compressive strength of the injectable bone substitutes were evaluated and observed to improve with the increase of bioactive glass content. Surface morphologies were observed via scanning electron microscope before and after submersion of the samples to simulated body fluid and increase in apatite formation was detected using x-ray diffraction machine. In vitro biocompatibility of the injectable bone substitutes was observed to improve with the addition of bioactive glass as the proliferation/adhesion behavior of cells on the material increased. Human gene markers were successfully expressed using real time-polymerase chain reaction and the samples were found to promote cell viability and be more biocompatible as the concentration of bioactive glass increases. In vivo biocompatibility of the samples containing 0% and 30% bioactive glass were evaluated using Micro-CT and histological staining after 3 months of implantation in male rabbits' femurs. No inflammatory reaction was observed and significant bone formation was promoted by the addition of bioactive glass to the injectable bone substitute system.

  15. Histological and mechanical evaluation of self-setting calcium phosphate cements in a sheep vertebral bone void model.

    Science.gov (United States)

    Kobayashi, Naomi; Ong, Kevin; Villarraga, Marta; Schwardt, Jeffrey; Wenz, Robert; Togawa, Daisuke; Fujishiro, Takaaki; Turner, A Simon; Seim, Howard B; Bauer, Thomas W

    2007-06-15

    We investigated the histological and compressive properties of three different calcium phosphate cements (CPCs) using a sheep vertebral bone void model. One of the CPCs contained barium sulfate to enhance its radiopacity. Bone voids were surgically created in the lumbar region of 23 ovine spines - L3, L4, and L5 (n = 69 total vertebral bodies) - and the voids were filled with one of the three CPCs. A fourth group consisted of whole intact vertebrae. Histologic evaluation was performed for 30 of the 69 vertebrae 2 or 4 months after surgery along with radiographic evaluation. Compressive testing was performed on 39 vertebrae 4 months after surgery along with micro-CT analysis. All three CPCs were biocompatible and extremely osteoconductive. Osteoclasts associated with adjacent bone formation suggest that each cement can undergo slow resorption and replacement by bone and bone marrow. Compressive testing did not reveal a significant difference in the ultimate strength, ultimate strain, and structural modulus, among the three CPCs and intact whole vertebrae. Micro-CT analysis revealed good osseointegration between all three CPCs and adjacent bone. The barium sulfate did not affect the CPCs biocompatibility or mechanical properties. These results suggest that CPC might be a good alternative to polymethylmethacrylate for selected indications.

  16. Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    2014-05-01

    Full Text Available Calcium carbonate is the material that builds up the spicules of the calcareous sponges. Recent results revealed that the calcium carbonate/biocalcite-based spicular skeleton of these animals is formed through an enzymatic mechanism, such as the skeleton of the siliceous sponges, evolutionarily the oldest animals that consist of biosilica. The enzyme that mediates the calcium carbonate deposition has been identified as a carbonic anhydrase (CA and has been cloned from the calcareous sponge species Sycon raphanus. Calcium carbonate deposits are also found in vertebrate bones besides the main constituent, calcium phosphate/hydroxyapatite (HA. Evidence has been presented that during the initial phase of HA synthesis poorly crystalline carbonated apatite is deposited. Recent data summarized here indicate that during early bone formation calcium carbonate deposits enzymatically formed by CA, act as potential bioseeds for the precipitation of calcium phosphate mineral onto bone-forming osteoblasts. Two different calcium carbonate phases have been found during CA-driven enzymatic calcium carbonate deposition in in vitro assays: calcite crystals and round-shaped vaterite deposits. The CA provides a new target of potential anabolic agents for treatment of bone diseases; a first CA activator stimulating the CA-driven calcium carbonate deposition has been identified. In addition, the CA-driven calcium carbonate crystal formation can be frozen at the vaterite state in the presence of silintaphin-2, an aspartic acid/glutamic acid-rich sponge-specific protein. The discovery that calcium carbonate crystals act as bioseeds in human bone formation may allow the development of novel biomimetic scaffolds for bone tissue engineering. Na-alginate hydrogels, enriched with biosilica, have recently been demonstrated as a suitable matrix to embed bone forming cells for rapid prototyping bioprinting/3D cell printing applications.

  17. Effect of biphasic calcium phosphate nanocomposite on healing of surgically created alveolar bone defects in beagle dogs

    Science.gov (United States)

    Wang, Lanlei; Guan, Aizhong; Shi, Han; Chen, Yangxi; Liao, Yunmao

    2009-09-01

    The aim of the present study was to investigate the effect of porous biphasic calcium phosphate nanocomposite (nanoBCP) scaffolds bioceramic. Alveolar bone defects were surgically created bilaterally at the buccal aspects of the upper second premolar in fourteen beagle dogs. After root conditioning with ethylenediaminetetraacetate (EDTA), nanoBCP was randomly filled in the defects and nothing was put into the contralaterals as controls. Dogs were killed at the 12th weeks. Histological observations were processed through a light microscopy. The results revealed that a great amount of functional periodontal fissures formed in the defects in the nanoBCP groups while minimal bone took shape in the controls. In this study, nanoBCP has proved to work well as a biocompatible and osteoconductive scaffold material to promote periodontal regeneration effectively.

  18. Firm anchoring between a calcium phosphate-hybridized tendon and bone for anterior cruciate ligament reconstruction in a goat model

    Energy Technology Data Exchange (ETDEWEB)

    Mutsuzaki, Hirotaka [Department of Orthopaedic Surgery, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Sakane, Masataka; Ochiai, Naoyuki [Department of Orthopaedic Surgery, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Hattori, Shinya; Kobayashi, Hisatoshi, E-mail: sakane-m@md.tsukuba.ac.j [Biomaterial Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2009-08-15

    Using an alternative soaking process improved the tendon-bone attachment for a calcium phosphate (CaP)-hybridized tendon graft. We characterized the deposited CaP on and in tendons and analyzed the histology and mechanical properties of the tendon-bone interface in anterior cruciate ligament (ACL) reconstruction in goats. The tendon grafts to be implanted were soaked ten times alternately in a Ca-containing solution and a PO{sub 4}-containing solution for 30 s each. Needlelike CaP nanocrystals including low-crystalline apatite were deposited on and between collagen fibrils from the surface to a depth of 200{mu}m inside the tendon. The structure resembles the extracellular matrix of bone. In animal experiments, the CaP-hybridized tendon directly bonded with newly formed bone at 6 weeks (n = 3), while fibrous bonding was observed in the control (n = 3). The ultimate failure load was not statistically different between the CaP (n = 7) and control (n = 7). However, in the failure mode, all the tendon-bone interfaces were intact in the CaP group, while three of seven specimens were pulled out from bone tunnels in the control. The result suggested that the strength of the tendon-bone interface in the CaP group is superior to that in the control group. Clinically, firm tendon-bone anchoring may lead to good results without the knee instability associated with the loosening of the bone-tendon junction in ACL reconstruction.

  19. In vitro evaluation of biomimetic chitosan-calcium phosphate scaffolds with potential application in bone tissue engineering.

    Science.gov (United States)

    Tanase, C E; Sartoris, A; Popa, M I; Verestiuc, L; Unger, R E; Kirkpatrick, C J

    2013-04-01

    This work reports on the physicochemical properties and in vitro cytotoxicity assessment of chitosan-calcium phosphate (Cs-CP) scaffolds for bone tissue engineering, which were synthesized by a novel biomimetic co-precipitation method. X-ray diffraction (XRD) along with scanning electron microscopy (SEM) analysis confirmed the porous morphology of the scaffolds and the amorphous nature of the inorganic phase with different crystallite sizes and the formation of various forms of calcium phosphate. Compressive mechanical testing revealed that the Young's modulus of the biomaterials is in the range of human trabecular bone. In vitro tests were performed on the biomaterials for up to 14 days to study the behavior of the osteoblast-like human cell line (MG63), primary human osteoblasts (HOS) and human dermal microvascular endothelial cells (HDMEC). The cytotoxicity was evaluated by the MTS assay for cell metabolism and the detection of membrane integrity (lactate dehydrogenase-LDH release). An expression of the vascular endothelial growth factor (VEGF) in the cell supernatants was quantified by ELISA. Cell viability gave values close to untreated controls for MG63 and HOS, while in the case of HDMEC the viability after 2 weeks in the cell culture was between 80-90%. The cytotoxicity induced by the Cs-CP scaffolds on MG63, HOS and HDMEC in vitro was evaluated by the amount of LDH released, which is a sensitive and accurate marker for cellular toxicity. The increased levels of VEGF obtained in the osteoblast culture highlights its important role in the regulation of vascularization and bone remodeling. The biological responses of the Cs-CP scaffolds demonstrate a similar proliferation and differentiation characteristics of the cells comparable to the controls. These results reveal that biomimetic Cs-CP composite scaffolds are promising biomaterials for bone tissue engineering; their in vivo response remains to be tested. PMID:23343569

  20. In vitro evaluation of biomimetic chitosan–calcium phosphate scaffolds with potential application in bone tissue engineering

    International Nuclear Information System (INIS)

    This work reports on the physicochemical properties and in vitro cytotoxicity assessment of chitosan–calcium phosphate (Cs–CP) scaffolds for bone tissue engineering, which were synthesized by a novel biomimetic co-precipitation method. X-ray diffraction (XRD) along with scanning electron microscopy (SEM) analysis confirmed the porous morphology of the scaffolds and the amorphous nature of the inorganic phase with different crystallite sizes and the formation of various forms of calcium phosphate. Compressive mechanical testing revealed that the Young's modulus of the biomaterials is in the range of human trabecular bone. In vitro tests were performed on the biomaterials for up to 14 days to study the behavior of the osteoblast-like human cell line (MG63), primary human osteoblasts (HOS) and human dermal microvascular endothelial cells (HDMEC). The cytotoxicity was evaluated by the MTS assay for cell metabolism and the detection of membrane integrity (lactate dehydrogenase-LDH release). An expression of the vascular endothelial growth factor (VEGF) in the cell supernatants was quantified by ELISA. Cell viability gave values close to untreated controls for MG63 and HOS, while in the case of HDMEC the viability after 2 weeks in the cell culture was between 80–90%. The cytotoxicity induced by the Cs–CP scaffolds on MG63, HOS and HDMEC in vitro was evaluated by the amount of LDH released, which is a sensitive and accurate marker for cellular toxicity. The increased levels of VEGF obtained in the osteoblast culture highlights its important role in the regulation of vascularization and bone remodeling. The biological responses of the Cs–CP scaffolds demonstrate a similar proliferation and differentiation characteristics of the cells comparable to the controls. These results reveal that biomimetic Cs–CP composite scaffolds are promising biomaterials for bone tissue engineering; their in vivo response remains to be tested. (paper)

  1. Editorial on the original article entitled "3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration" published in the Biomaterials on February 14, 2014.

    Science.gov (United States)

    Li, Lan; Jiang, Qing

    2015-05-01

    The paper entitled "3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration" published in the Biomaterials recently illuminated the way to make particular scaffolds with calcium phosphate (CaP) powder, phosphoric acid, type I collagen and Tween 80 in low temperature. After the optimal concentration of each component was determined, the scaffolds were evaluated in a critically sized murine femoral defect model and exhibited good material properties. We made some related introduction of materials applied in 3D printing for bone tissue engineering based on this article to demonstrate the current progress in this field of study.

  2. Bone formation of a porous Gelatin-Pectin-biphasic calcium phosphate composite in presence of BMP-2 and VEGF.

    Science.gov (United States)

    Amirian, Jhaleh; Linh, Nguyen Thuy Ba; Min, Young Ki; Lee, Byong-Taek

    2015-05-01

    A composite scaffold of gelatin (Gel)-pectin (Pec)-biphasic calcium phosphate (BCP) was fabricated for the successful delivery of growth factors. Bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) were coated on the Gel-Pec-BCP surface to investigate of effect of them on bone healing. Surface morphology was investigated by scanning electron microscopy, and BCP dispersion in the hydrogel scaffolds was measured by energy dispersive X-ray spectroscopy. The results obtained from Fourier transform infrared spectroscopy showed that BMP-2 and VEGF were successfully coated on Gel-Pec-BCP hydrogel scaffolds. MC3T3-E1 preosteoblasts were cultivated on the scaffolds to investigate the effect of BMP-2 and VEGF on cell viability and proliferation. VEGF and BMP-2 loaded on Gel-Pec-BCP scaffold facilitated increased cell spreading and proliferation compared to Gel-Pec-BCP scaffolds. In vivo, bone formation was examined using rat models. Bone formation was observed in Gel-Pec-BCP/BMP-2 and Gel-Pec-BCP/VEGF scaffolds within 4 weeks, and was greatest with Gel-Pec-BCP/BMP-2 scaffolds. In vitro and in vivo results suggest that Gel-Pec-BCP/BMP-2 and Gel-Pec-BCP/VEGF scaffolds could enhance bone regeneration.

  3. Fabrication and materials properties of high-density polyethylene (HDPE)/biphasic calcium phosphate (BCP) hybrid bone plates

    International Nuclear Information System (INIS)

    Biphasic calcium phosphate-reinforced high-density polyethylene (BCP/HDPE) hybrid composite is a new orthopedic biomaterial, which was made to simulate a natural bone composition. Calcium phosphate systems and HDPE hybrid composites have been used in biomedical applications without any inflammatory response. Differences in natural bone of both materials have motivated the use of coupling agents to improve their interfacial interfacial interactions. The composites were prepared using medical grade BCP powder and granular polyethylene. This material was produced by replacing the mineral component and collagen soft tissue of the bone with BCP and HDPE, respectively. As expected, increased volume fraction of either reinforcement type over 0 ∼ 50 vol.% resulted in a increased Vickers hardness and Young's modulus. Thus, BCP particle-reinforced HDPE composites possessed improved material and mechanical properties. BCP particles-reinforced composites were anisotropic due to an alignment of the particles in the matrix during a processing. On the other hand, bending and tensile strength was dramatically changed in the matrix. To change the material and mechanical properties of HDPE/BCP composites, the process of a blending was used, and its effect on the microstructure and mechanical proprieties of HDPE/BCP composites were investigated by means of FT-IR/ATR spectroscopy, XRD, FE-SEM, Vickers Hardness Testing Machine, Universal Testing Machine, Mercury Porosimeter and Ultrasonic Flaw Detector at room temperature. For the evaluation of the cell viability and proliferation onto the external surface of HDPE/BCP hybrid plates with a HaCaT cell line, which is a multipotent cell line able to differentiate towards different phenotypes under the action of biological factors, has been evaluated with in vitro studies and quantified by colormetric assays. These findings indicate that the HDPE/BCP hybrid plates are biocompatible and non-toxic

  4. The stability mechanisms of an injectable calcium phosphate ceramic suspension.

    OpenAIRE

    Fatimi, Ahmed; Tassin, Jean-François; Axelos, Monique,; Weiss, Pierre

    2010-01-01

    International audience Calcium phosphate ceramics are widely used as bone substitutes in dentistry and orthopedic applications. For minimally invasive surgery an injectable calcium phosphate ceramic suspension (ICPCS) was developed. It consists in a biopolymer (hydroxypropylmethylcellulose: HPMC) as matrix and bioactive calcium phosphate ceramics (biphasic calcium phosphate: BCP) as fillers. The stability of the suspension is essential to this generation of "ready to use" injectable biomat...

  5. Ectopic bone formation using an injectable biphasic calcium phosphate/Si-HPMC hydrogel composite loaded with undifferentiated bone marrow stromal cells.

    Science.gov (United States)

    Trojani, Christophe; Boukhechba, Florian; Scimeca, Jean-Claude; Vandenbos, Fanny; Michiels, Jean-François; Daculsi, Guy; Boileau, Pascal; Weiss, Pierre; Carle, Georges F; Rochet, Nathalie

    2006-06-01

    We have used a new synthetic injectable composite constituted of hydroxyapatite/tricalcium phosphate (HA/TCP) particles in suspension in a self-hardening Si-hydroxypropylmethylcellulose (HPMC) hydrogel. The aim of this study was to evaluate in vivo the biocompatibility and the new bone formation efficacy of this scaffold loaded with undifferentiated bone marrow stromal cells (BMSCs). This biomaterial was mixed extemporaneously with BMSCs prepared from C57BL/6 mice, injected in subcutaneous and intramuscular sites and retrieved 4 and 8 weeks after implantation. Dissection of the implants revealed a hard consistency and the absence of a fibrous capsule reflecting a good integration into the host tissues. Histological analysis showed mineralized woven bone in the granule inter-space with numerous active osteoclasts attached to the particles as assessed by the presence of multinucleated cells positively stained for TRAP activity and for the a3 subunit of the V-ATPase. Small vessels were homogenously distributed in the whole implants. Similar results were obtained in SC and IM sites and no bone formation was observed in the control groups when cell-free and particle-free transplants were injected. These results indicate that this injectable biphasic calcium phosphate-hydrogel composite mixed with undifferentiated BMSCs is a new promising osteoinductive bone substitute. It also provides with an original in vivo model of osteoclast differentiation and function. PMID:16510180

  6. Ectopic bone formation by 3D porous calcium phosphate-Ti6Al4V hybrids produced by perfusion electrodeposition.

    Science.gov (United States)

    Chai, Yoke Chin; Kerckhofs, Greet; Roberts, Scott J; Van Bael, Simon; Schepers, Evert; Vleugels, Jozef; Luyten, Frank P; Schrooten, Jan

    2012-06-01

    Successful clinical repair of non-healing skeletal defects requires the use of bone substitutes with robust bone inductivity and excellent biomechanical stability. Thus, three-dimensionally functionalised porous calcium phosphate-Ti6Al4V (CaP-Ti) hybrids were produced by perfusion electrodeposition, and the in vitro and in vivo biological performances were evaluated using human periosteum derived cells (hPDCs). By applying various current densities at the optimised deposition conditions, CaP coatings with sub-micrometer to nano-scale porous crystalline structures and different ion dissolution kinetics were deposited on the porous Ti6Al4V scaffolds. These distinctive physicochemical properties caused a significant impact on in vitro proliferation, osteogenic differentiation, and matrix mineralisation of hPDCs. This includes a potential role of hPDCs in mediating osteoclastogenesis for the resorption of CaP coatings, as indicated by a significant down-regulation of osteoprotegerin (OPG) gene expression and by the histological observation of abundant multi-nucleated giant cells near to the coatings. By subcutaneous implantation, the produced hybrids induced ectopic bone formation, which was highly dependent on the physicochemical properties of the CaP coating (including the Ca(2+) dissolution kinetics and coating surface topography), in a cell density-dependent manner. This study provided further insight on stem cell-CaP biomaterial interactions, and the feasibility to produced bone reparative units that are predictively osteoinductive in vivo by perfusion electrodeposition technology.

  7. Poly(lactic acid) porous scaffold with calcium phosphate mineralized surface and bone marrow mesenchymal stem cell growth and differentiation

    International Nuclear Information System (INIS)

    This work aims to modify the surface of a poly(lactic acid) (PLA) porous scaffold with calcium phosphate (CaP) via a simple solution-based technique, and to evaluate the effects of this modification on the responses of rat bone marrow mesenchymal stem cells (rBMMSCs). Under appropriate modification conditions involving stepwise-treatments in the Ca-and-P supersaturated solution under gentle agitation, a thin, poorly crystallized CaP layer was deposited. The BMMSCs derived from adult rats were shown to adhere quite well to the CaP-coated scaffold, and to proliferate actively with culturing time, although some down-regulation was noted with regard to the unmodified PLA scaffold. The osteogenic differentiation of rBMMSCs was significantly higher on the CaP-modified scaffold than on the unmodified scaffold, as confirmed by alkaline phosphatase (ALP) activity. Moreover, the expression of genes associated with bone, including collagen type I, osteopontin and bone sialoprotein, was stimulated better on the CaP-modified PLA scaffold. Based on these results, the currently used CaP-treatment was deemed effective in stimulating the osteogenic development of rBMMSCs on the PLA-based scaffold, and the CaP-treated PLA scaffold may be useful for future bone tissue engineering.

  8. Biomimetic fabrication of a three-level hierarchical calcium phosphate/collagen/hydroxyapatite scaffold for bone tissue engineering

    International Nuclear Information System (INIS)

    A three-level hierarchical calcium phosphate/collagen/hydroxyapatite (CaP/Col/HAp) scaffold for bone tissue engineering was developed using biomimetic synthesis. Porous CaP ceramics were first prepared as substrate materials to mimic the porous bone structure. A second-level Col network was then composited into porous CaP ceramics by vacuum infusion. Finally, a third-level HAp layer was achieved by biomimetic mineralization. The three-level hierarchical biomimetic scaffold was characterized using scanning electron microscopy, energy-dispersive x-ray spectra, x-ray diffraction and Fourier transform infrared spectroscopy, and the mechanical properties of the scaffold were evaluated using dynamic mechanical analysis. The results show that this scaffold exhibits a similar structure and composition to natural bone tissues. Furthermore, this three-level hierarchical biomimetic scaffold showed enhanced mechanical strength compared with pure porous CaP scaffolds. The biocompatibility and osteoinductivity of the biomimetic scaffolds were evaluated using in vitro and in vivo tests. Cell culture results indicated the good biocompatibility of this biomimetic scaffold. Faster and increased bone formation was observed in these scaffolds following a six-month implantation in the dorsal muscles of rabbits, indicating that this biomimetic scaffold exhibits better osteoinductivity than common CaP scaffolds. (papers)

  9. Comparison of three calcium phosphate bone graft substitutes from biomechanical, histological, and crystallographic perspectives using a rat posterolateral lumbar fusion model.

    Science.gov (United States)

    Hu, Ming-Hsien; Lee, Pei-Yuan; Chen, Wen-Cheng; Hu, Jin-Jia

    2014-12-01

    This study evaluated the effectiveness of three calcium phosphate bone graft substitutes with different chemical compositions on spinal fusion using a rat posterolateral lumbar fusion model. Specifically, two recently developed non-dispersive tetracalcium phosphate/dicalcium phosphate anhydrous-based calcium phosphate cements (CPCs), namely a CPC consisting of equimolar amounts of the two compounds (nd-CPC) and a CPC consisting of a two-fold greater amount of dicalcium phosphate anhydrous (DCP-rich CPC), were compared with a commercial calcium phosphate bone graft (c-CPG) consisting of hydroxyapatite (60%) and β-tricalcium phosphate (40%). Single-level posterolateral lumbar fusion was performed at the L4-L5 vertebrae in fifteen adult rats (n=5 for each group). Spinal fusion was evaluated with radiographs, manual palpation, mechanical testing, micro-CT, and histology 8 weeks post-surgery. In particular, the crystallographic phases in the three substitutes were identified before and 8 weeks after their implantation. Manual palpation revealed stable constructs in nearly all of the spine specimens. The stiffness and bending load of fused spines in the two CPC groups were comparable to those in the c-CPG group. The radiographs specifically revealed implant resorption and bone remodeling in the DCP-rich CPC group. Analysis of 3D micro-CT images revealed that the bone volume ratio in the DCP-rich CPC group was significantly greater than those in the nd-CPC and c-CPG groups. Histology showed that the DCP-rich CPC group exhibited the highest degree of bone regeneration and osseointegration. Notably, DCP-rich CPC led to a pronounced phase transformation, generating the greatest amount of poorly crystalline apatite among the three groups, which together with adequate resorption may explain the aforementioned positive findings. We therefore conclude that of the bone graft substitutes considered, DCP-rich CPC has the greatest potential to be used in spinal fusion.

  10. Comparison of three calcium phosphate bone graft substitutes from biomechanical, histological, and crystallographic perspectives using a rat posterolateral lumbar fusion model.

    Science.gov (United States)

    Hu, Ming-Hsien; Lee, Pei-Yuan; Chen, Wen-Cheng; Hu, Jin-Jia

    2014-12-01

    This study evaluated the effectiveness of three calcium phosphate bone graft substitutes with different chemical compositions on spinal fusion using a rat posterolateral lumbar fusion model. Specifically, two recently developed non-dispersive tetracalcium phosphate/dicalcium phosphate anhydrous-based calcium phosphate cements (CPCs), namely a CPC consisting of equimolar amounts of the two compounds (nd-CPC) and a CPC consisting of a two-fold greater amount of dicalcium phosphate anhydrous (DCP-rich CPC), were compared with a commercial calcium phosphate bone graft (c-CPG) consisting of hydroxyapatite (60%) and β-tricalcium phosphate (40%). Single-level posterolateral lumbar fusion was performed at the L4-L5 vertebrae in fifteen adult rats (n=5 for each group). Spinal fusion was evaluated with radiographs, manual palpation, mechanical testing, micro-CT, and histology 8 weeks post-surgery. In particular, the crystallographic phases in the three substitutes were identified before and 8 weeks after their implantation. Manual palpation revealed stable constructs in nearly all of the spine specimens. The stiffness and bending load of fused spines in the two CPC groups were comparable to those in the c-CPG group. The radiographs specifically revealed implant resorption and bone remodeling in the DCP-rich CPC group. Analysis of 3D micro-CT images revealed that the bone volume ratio in the DCP-rich CPC group was significantly greater than those in the nd-CPC and c-CPG groups. Histology showed that the DCP-rich CPC group exhibited the highest degree of bone regeneration and osseointegration. Notably, DCP-rich CPC led to a pronounced phase transformation, generating the greatest amount of poorly crystalline apatite among the three groups, which together with adequate resorption may explain the aforementioned positive findings. We therefore conclude that of the bone graft substitutes considered, DCP-rich CPC has the greatest potential to be used in spinal fusion. PMID

  11. Sintering of calcium phosphate bioceramics.

    Science.gov (United States)

    Champion, E

    2013-04-01

    Calcium phosphate ceramics have become of prime importance for biological applications in the field of bone tissue engineering. This paper reviews the sintering behaviour of these bioceramics. Conventional pressureless sintering of hydroxyapatite, Ca10(PO4)6(OH)2, a reference compound, has been extensively studied. Its physico-chemistry is detailed. It can be seen as a competition between two thermally activated phenomena that proceed by solid-state diffusion of matter: densification and grain growth. Usually, the objective is to promote the first and prevent the second. Literature data are analysed from sintering maps (i.e. grain growth vs. densification). Sintering trajectories of hydroxyapatite produced by conventional pressureless sintering and non-conventional techniques, including two-step sintering, liquid phase sintering, hot pressing, hot isostatic pressing, ultrahigh pressure, microwave and spark plasma sintering, are presented. Whatever the sintering technique may be, grain growth occurs mainly during the last step of sintering, when the relative bulk density reaches 95% of the maximum value. Though often considered very advantageous, most assisted sintering techniques do not appear very superior to conventional pressureless sintering. Sintering of tricalcium phosphate or biphasic calcium phosphates is also discussed. The chemical composition of calcium phosphate influences the behaviour. Similarly, ionic substitutions in hydroxyapatite or in tricalcium phosphate create lattice defects that modify the sintering rate. Depending on their nature, they can either accelerate or slow down the sintering rate. The thermal stability of compounds at the sintering temperature must also be taken into account. Controlled atmospheres may be required to prevent thermal decomposition, and flash sintering techniques, which allow consolidation at low temperature, can be helpful. PMID:23212081

  12. New depowdering-friendly designs for three-dimensional printing of calcium phosphate bone substitutes.

    Science.gov (United States)

    Butscher, A; Bohner, M; Doebelin, N; Hofmann, S; Müller, R

    2013-11-01

    Powder-based three-dimensional printing (3DP) is a versatile method that allows creating synthetic calcium phosphate (CaP) scaffolds of complex shapes and structures. However, one major drawback is the difficulty of removing all remnants of loose powder from the printed scaffolds, the so-called depowdering step. In this study, a new design approach was proposed to solve this problem. Specifically, the design of the printed scaffolds consisted of a cage with windows large enough to enable depowdering while still trapping loose fillers placed inside the cage. To demonstrate the potential of this new approach, two filler geometries were used: sandglass and cheese segment. The distance between the fillers was varied and they were either glued to the cage or free to move after successful depowdering. Depowdering efficiency was quantified by microstructural morphometry. The results showed that the use of mobile fillers significantly improved depowdering. Based on this study, large 3DP scaffolds can be realized, which might be a step towards a broader clinical use of 3D printed CaP scaffolds.

  13. Biphasic calcium sulfate dihydrate/iron-modified alpha-tricalcium phosphate bone cement for spinal applications: in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Vlad, M D; Lopez, J; Torres, R; Barraco, M; Fernandez, E [Interdepartment Research Group for the Applied Scientific Collaboration (IRGASC), Division of Biomaterials and Bioengineering, Technical University of Catalonia (UPC), Avda Diagonal 647, E-08028-Barcelona (Spain); Valle, L J [Centre of Molecular Biotechnology (CEBIM), Department of Agri-Food Engineering and Biotechnology, ESAB, UPC, Avda Canal Olimpico 15, E-08860-Castelldefels (Spain); Poeata, I, E-mail: enrique.fernandez@upc.ed [Faculty of Medical Bioengineering, ' Gr T Popa' University of Medicine and Pharmacy, Str. Kogalniceanu 9-13, 700454 Iasi (Romania)

    2010-04-15

    In this study, the cytocompatibility of new 'iron-modified/alpha-tricalcium phosphate (IM/alpha-TCP) and calcium sulfate dihydrate (CSD)' bone cement (IM/alpha-TCP/CSD-BC) intended for spinal applications has been approached. The objective was to investigate by direct-contact osteoblast-like cell cultures (from 1 to 14 days) the in vitro cell adhesion, proliferation, morphology and cytoskeleton organization of MG-63 cells seeded onto the new cements. The results were as follows: (a) quantitative MTT-assay and scanning electron microscopy (SEM) showed that cell adhesion, proliferation and viability were not affected with time by the presence of iron in the cements; (b) double immunofluorescent labeling of F-actin and alpha-tubulin showed a dynamic interaction between the cell and its porous substrates sustaining the locomotion phenomenon on the cements' surface, which favored the colonization, and confirming the biocompatibility of the experimental cements; (c) SEM-cell morphology and cytoskeleton observations also evidenced that MG-63 cells were able to adhere, to spread and to attain normal morphology on the new IM/alpha-TCP/CSD-BC which offered favorable substratum properties for osteoblast-like cells proliferation and differentiation in vitro. The results showed that these new iron-modified cement-like biomaterials have cytocompatible features of interest not only as possible spinal cancellous bone replacement biomaterial but also as bone tissue engineering scaffolds.

  14. Axial vascularization of a large volume calcium phosphate ceramic bone substitute in the sheep AV loop model.

    Science.gov (United States)

    Beier, Justus P; Horch, Raymund E; Hess, Andreas; Arkudas, Andreas; Heinrich, Johanna; Loew, Johanna; Gulle, Heinz; Polykandriotis, Elias; Bleiziffer, Oliver; Kneser, Ulrich

    2010-03-01

    Vascularization still remains an obstacle to engineering of bone tissue with clinically relevant dimensions. Our aim was to induce axial vascularization in a large volume of a clinically approved biphasic calcium phosphate ceramic by transferring the arteriovenous (AV) loop approach to a large animal model. HA/beta-TCP granula were mixed with fibrin gel for a total volume of 16 cm(3), followed by incorporation into an isolation chamber together with an AV loop. The chambers were implanted into the groins of merino sheep and the development of vascularization was monitored by sequential non-invasive magnetic resonance imaging (MRI). The chambers were explanted after 6 and 12 weeks, the pedicle was perfused with contrast agent and specimens were subjected to micro-computed tomography (micro-CT) scan and histological analysis. Sequential MRI demonstrated a significantly increased perfusion in the HA/beta-TCP matrices over time. Micro-CT scans and histology confirmed successful axial vascularization of HA/beta-TCP constructs. This study demonstrates, for the first time, successful axial vascularization of a clinically approved bone substitute with a significant volume in a large animal model by means of a microsurgically created AV loop, thus paving the way for the first microsurgical transplantation of a tissue-engineered, axially vascularized bone with clinically relevant dimensions.

  15. Instructive function of surface structure of calcium phosphate ceramics in bone regeneration

    NARCIS (Netherlands)

    Zhang, Jingwei

    2016-01-01

    The incidence of patients which require spinal fusion or bone regeneration in large bone defects caused by trauma, tumors, tumor resection, infections or abnormal skeletal development, is on the rise. Traditionally, in both spinal fusion surgery and other bone regeneration approaches, bone grafts ar

  16. Comparison of three calcium phosphate bone graft substitutes from biomechanical, histological, and crystallographic perspectives using a rat posterolateral lumbar fusion model

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ming-Hsien [Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Orthopedics, Show-Chwan Memorial Hospital, Changhua 50544, Taiwan (China); Department of Orthopedic Surgery, Faculty of Medicine, National Yang-Ming University, Taipei 112, Taiwan (China); Lee, Pei-Yuan [Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Orthopedics, Show-Chwan Memorial Hospital, Changhua 50544, Taiwan (China); Chen, Wen-Cheng, E-mail: wincheng0925@yahoo.com.tw [Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Hu, Jin-Jia, E-mail: jjhu@mail.ncku.edu.tw [Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Medical Device Innovation Center, National Cheng Kung University, Tainan 701, Taiwan (China)

    2014-12-01

    This study evaluated the effectiveness of three calcium phosphate bone graft substitutes with different chemical compositions on spinal fusion using a rat posterolateral lumbar fusion model. Specifically, two recently developed non-dispersive tetracalcium phosphate/dicalcium phosphate anhydrous-based calcium phosphate cements (CPCs), namely a CPC consisting of equimolar amounts of the two compounds (nd-CPC) and a CPC consisting of a two-fold greater amount of dicalcium phosphate anhydrous (DCP-rich CPC), were compared with a commercial calcium phosphate bone graft (c-CPG) consisting of hydroxyapatite (60%) and β-tricalcium phosphate (40%). Single-level posterolateral lumbar fusion was performed at the L4–L5 vertebrae in fifteen adult rats (n = 5 for each group). Spinal fusion was evaluated with radiographs, manual palpation, mechanical testing, micro-CT, and histology 8 weeks post-surgery. In particular, the crystallographic phases in the three substitutes were identified before and 8 weeks after their implantation. Manual palpation revealed stable constructs in nearly all of the spine specimens. The stiffness and bending load of fused spines in the two CPC groups were comparable to those in the c-CPG group. The radiographs specifically revealed implant resorption and bone remodeling in the DCP-rich CPC group. Analysis of 3D micro-CT images revealed that the bone volume ratio in the DCP-rich CPC group was significantly greater than those in the nd-CPC and c-CPG groups. Histology showed that the DCP-rich CPC group exhibited the highest degree of bone regeneration and osseointegration. Notably, DCP-rich CPC led to a pronounced phase transformation, generating the greatest amount of poorly crystalline apatite among the three groups, which together with adequate resorption may explain the aforementioned positive findings. We therefore conclude that of the bone graft substitutes considered, DCP-rich CPC has the greatest potential to be used in spinal fusion

  17. The mechanical and biological studies of calcium phosphate cement-fibrin glue for bone reconstruction of rabbit femoral defects

    Directory of Open Access Journals (Sweden)

    Dong J

    2013-03-01

    Full Text Available Jingjing Dong,1,* Geng Cui,2,* Long Bi,1,* Jie Li,3 Wei Lei11Institute of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China; 2Institute of Orthopedics, General Hospital of PLA, Beijing, People’s Republic of China; 3Institute of Gynecology and Obstetrics, General Hospital of PLA, Beijing, People’s Republic of China*These authors contributed equally to this workAbstract: In order to improve the mechanical and biological properties of calcium phosphate cement (CPC, nanometer-biomaterial for bone reconstruction in the rabbit femoral defect model, fibrin glue (FG, the natural product, purified from the blood was introduced at three different ratios. The CPC powder and the FG solution were mixed, respectively, at the powder/liquid (P/L ratios (g/mL of 1:1, 3:1, and 5:1 (g/mL, and pure CPC was used as a control. After being implanted into the femoral defect in rabbit, the healing process was evaluated by micro-computed tomography scan, biomechanical testing, and histological examination. By micro-computed tomography analysis, the P/L ratio of 1:1 (g/mL group indicated the largest quantity of new bone formation at 4 weeks, 8 weeks, and 12 weeks after implantation, respectively. Bone volume per trabecular volume of the 1:1 group was highest in the four groups, which was 1.45% ± 0.42%, 7.35% ± 1.45%, and 29.10% ± 1.67% at 4 weeks, 8 weeks, and 12 weeks after the operation, respectively. In the biomechanical tests, the compressive strength and the elastic modulus of the three CPC–FG groups were much higher than those of the pure CPC group at the determined time point (P < 0.05. The histological evaluation also showed the best osseointegration in the 1:1 group at 4 weeks, 8 weeks, and 12 weeks after the operation, respectively. In the 1:1 group, the bone grew into the pore of the cement in the laminar arrangement and connected with the cement tightly at the 12th week after the operation

  18. Using calcium silicate to regulate the physicochemical and biological properties when using β-tricalcium phosphate as bone cement

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Chia-Tze; Huang, Tsui-Hsien [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chen, Yi-Jyun [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Dental Department, Taichung Hospital, Ministry of Health and Welfare, Taichung City, Taiwan (China); Hung, Chi-Jr [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lin, Chi-Chang, E-mail: chichang31@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China)

    2014-10-01

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on β-TCP/CS composites. The results show that the apatite deposition ability of the β-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% β-TCP cements, respectively. In addition, the antibacterial activity of CS/β-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the β-TCP/CS composites. The degradation of β-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials. - Highlights: • CS improved the physicochemical properties and osteogenic activity of β-TCP. • Higher CS in the composite, the shorter setting time and the higher DTS was found. • With a CS more than 40%, the osteogenesis and angiogenesis proteins were promoted by

  19. Using calcium silicate to regulate the physicochemical and biological properties when using β-tricalcium phosphate as bone cement

    International Nuclear Information System (INIS)

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on β-TCP/CS composites. The results show that the apatite deposition ability of the β-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% β-TCP cements, respectively. In addition, the antibacterial activity of CS/β-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the β-TCP/CS composites. The degradation of β-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials. - Highlights: • CS improved the physicochemical properties and osteogenic activity of β-TCP. • Higher CS in the composite, the shorter setting time and the higher DTS was found. • With a CS more than 40%, the osteogenesis and angiogenesis proteins were promoted by

  20. Printability of calcium phosphate: calcium sulfate powders for the application of tissue engineered bone scaffolds using the 3D printing technique.

    Science.gov (United States)

    Zhou, Zuoxin; Buchanan, Fraser; Mitchell, Christina; Dunne, Nicholas

    2014-05-01

    In this study, calcium phosphate (CaP) powders were blended with a three-dimensional printing (3DP) calcium sulfate (CaSO4)-based powder and the resulting composite powders were printed with a water-based binder using the 3DP technology. Application of a water-based binder ensured the manufacture of CaP:CaSO4 constructs on a reliable and repeatable basis, without long term damage of the printhead. Printability of CaP:CaSO4 powders was quantitatively assessed by investigating the key 3DP process parameters, i.e. in-process powder bed packing, drop penetration behavior and the quality of printed solid constructs. Effects of particle size, CaP:CaSO4 ratio and CaP powder type on the 3DP process were considered. The drop penetration technique was used to reliably identify powder formulations that could be potentially used for the application of tissue engineered bone scaffolds using the 3DP technique. Significant improvements (pprinted constructs were manufactured, which exhibited appropriate green compressive strength and a high level of printing accuracy.

  1. Bone healing response to a synthetic calcium sulfate/β-tricalcium phosphate graft material in a sheep vertebral body defect model

    OpenAIRE

    Yang, H. L.; Zhu, X S; Chen, L.; Chen, C. M.; Mangham, D C; Coulton, L A; Aiken, S. S.

    2012-01-01

    Abstract The introduction of a material able to promote osteogenesis and remodelling activity in a clinically relevant time frame in vertebroplasty and kyphoplasty procedures may have patient benefit. We report the in-vivo performance of a biphasic synthetic bone graft material (Genex Paste, Biocomposites, UK) [test material], composed of calcium sulfate and β-tricalcium phosphate, implanted into a sheep vertebral defect model. Cavities drilled into 4 adjacent vertebrae (L2 to L5) of 24 skele...

  2. Synthesis and characterization of porous biphasic calcium phosphate scaffold from different porogens for possible bone tissue engineering applications

    Directory of Open Access Journals (Sweden)

    Amera A.

    2011-01-01

    Full Text Available By using the wet precipitation method, Biphasic calcium phosphate granules were synthesized with Ca/P ratio1.52 and controlled porosity, pore size distribution, and granule size. Microporosity was then obtained by adjusting sintering temperature while macroporosity was prepared by adding 1:3 wt% ratio of two normally used porogens (naphthalene and sugar and 2 newly introduced porogens (sago and lentil. Samples from each ratio were pressed into pellets and were fired at 500ºC for 2 hours with 0.5°C/minute heating rate (for removal of porogens and further sintered at 850°C for 2 hours with 5°C/minute before cooling down to room temperature. The granules were prepared by crushing and sieving BCP sintered pellets to get granules of sizes ranging from 250-500μm. X-rays diffraction (XRD, field emission scanning electron microscope (FESEM, particle size and porosity analyses were employed in order to characterize the granules. A round to oval shape pores with 200-400 μm size were obtained and identical to the prepared porogens’ particle size. This approach gives the desirable properties near to normal bone leading to a perfect osteogenesis for the purpose tissue engineering.

  3. Comparison and preparation of multilayered polylactic acid fabric strengthen calcium phosphate-based bone substitutes for orthopedic applications.

    Science.gov (United States)

    Chen, Wen-Cheng; Ko, Chia-Ling; Yang, Jia-Kai; Wu, Hui-Yu; Lin, Jia-Horng

    2016-03-01

    An attempt to maintain the three-dimensional space into restorative sites through the conveniently pack porous fillers are general used strategy. Advancement in the manufacturing protective shells in the scaffolds, which would be filled with brittle ceramic grafts for the development of highly connective pores provides the approach to solve crack problem for generating the tissues. Therefore, multilayered braided and alkalized poly(lactic acid) (PLA) composites with calcium phosphate bone cement (CPC) were synthesized and compared. The PLA/CPC composites were divided into various groups according to a series of heat-treatment temperatures (100-190 °C) and periods (1-3 h) and then characterized. The effects of 24-h immersion on the strength decay resistance of the samples were compared. Results showed that the residual oil capped on the surfaces of alkalized PLA braid was removed, and the structure was unaltered. However, the reduced tensile stress of alkalized PLA braids was due to ester-group formation by hydrolysis. Mechanical test results of PLA/CPC composites showed that the strength significantly increased after heat treatment, except when the heating temperature was higher than the PLA melting point at approximately 160-170 °C. The degree of PLA after recrystallization became higher than that of unheated composites, thereby leading to reduced strength and toughness of the specimen. Braiding fibers of biodegradable PLA reinforced and toughened the structure particularly of the extra-brittle material of thin-sheet CPC after implantation.

  4. The homing of bone marrow MSCs to non-osseous sites for ectopic bone formation induced by osteoinductive calcium phosphate.

    NARCIS (Netherlands)

    Song, G.; Habibovic, P.; Bao, C.; Hu, J.; Blitterswijk, van C.A.; Yuan, H.; Chen, W.; Xu, H.H.K.

    2013-01-01

    Osteoinductive biomaterials are promising for bone repair. There is no direct proof that bone marrow mesenchymal stem cells (BMSCs) home to non-osseous sites and participate in ectopic bone formation induced by osteoinductive bioceramics. The objective of this study was to use a sex-mismatched beagl

  5. Preparation and characterization of calcium phosphate ceramics and Composites as bone substitutes

    OpenAIRE

    Zhang, Xing

    2007-01-01

    Marine CaCO₃ skeletons have tailored architectures created by nature, which give them structural support and other functions. For example, seashells have dense lamellar structures, while coral, cuttlebone and sea urchin spines have interconnected porous structures. In our experiments, seashells, coral and cuttlebone were hydrothermally converted to hydroxyapatite (HAP), and sea urchin spines were converted to Mg-substituted tricalcium phosphate [beta]-TCMP, while maintaining their original st...

  6. Silicon, iron and titanium doped calcium phosphate-based glass reinforced biodegradable polyester composites as bone analogous materials

    Science.gov (United States)

    Shah Mohammadi, Maziar

    Bone defects resulting from disease or traumatic injury is a major health care problem worldwide. Tissue engineering offers an alternative approach to repair and regenerate bone through the use of a cell-scaffold construct. The scaffold should be biodegradable, biocompatible, porous with an open pore structure, and should be able to withstand the applied forces. Phosphate-based glasses (PGs) may be used as reinforcing agents in degradable composites since their degradation can be predicted and controlled through their chemistry. This doctoral dissertation describes the development and evaluation of PGs reinforced biodegradable polyesters for intended applications in bone augmentation and regeneration. This research was divided into three main objectives: 1) Investigating the composition dependent properties of novel PG formulations by doping a sodium-free calcium phosphate-based glass with SiO2, Fe2O3, and TiO2. Accordingly, (50P2 O5-40CaO- xSiO2-(10-x)Fe2O3, where x = 10, 5 and 0 mol.%) and (50P2O5-40CaO-xSiO 2-(10-x)TiO2 where x = 10, 7, 5, 3 and 0 mol.%) formulations were developed and characterised. SiO2 incorporation led to increased solubility, ion release, pH reduction, as well as hydrophilicity, surface energy, and surface polarity. In contrast, doping with Fe2O 3 or TiO2 resulted in more durable glasses, and improved cell attachment and viability. It was hypothesised that the presence of SiO 2 in the TiO2-doped formulations could up-regulate the ionic release from the PG leading to higher alkaline phosphatase activity of MC3T3-E1 cells. 2) Incorporating Si, Fe, and Ti doped PGs as fillers, either as particulates (PGPs) or fibres (PGFs), into biodegradable polyesters (polycaprolactone (PCL) and semi-crystalline and amorphous poly(lactic acid) (PLA and PDLLA)) with the aim of developing degradable bone analogous composites. It was found that PG composition and geometry dictated the weight loss, ionic release, and mechanical properties of the composites. It

  7. Osteoclast-like cells on deproteinized bovine bone mineral and biphasic calcium phosphate

    DEFF Research Database (Denmark)

    Jensen, Simon S; Gruber, Reinhard; Buser, Daniel;

    2015-01-01

    OBJECTIVES: The occurrence of multinucleated giant cells (MNGCs) on bone substitute materials has been recognized for a long time. However, there have been no studies linking material characteristics with morphology of the MNGCs. The aim was to analyze the qualitative differences of MNGCs on two...... microscopy. RESULTS: Multinucleated giant cells appeared on both biomaterials. On BCP, MNGCs had a flat morphology and were not observed in resorption lacunae. On DBBM, the MNGCs appeared more round and were often found in shallow concavities. MNGCs on both biomaterials demonstrated a varying degree of TRAP...... osteoclasts. CONCLUSION: MNGCs demonstrated distinctly different histological features depending on the bone substitute material used. Further research is warranted to understand the clinical implications of these morphological observations....

  8. Ectopic bone formation in bone marrow stem cell seeded calcium phosphate scaffolds as compared to autograft and (cell seeded) allograft

    NARCIS (Netherlands)

    Eniwumide, J.O.; Yuan, H.; Cartmell, S.H.; Meijer, G.J.; Bruijn, J.D. de

    2007-01-01

    Improvements to current therapeutic strategies are needed for the treatment of skeletal defects. Bone tissue engineering offers potential advantages to these strategies. In this study, ectopic bone formation in a range of scaffolds was assessed. Vital autograft and devitalised allograft served as co

  9. Reactive calcium-phosphate-containing poly(ester-co-ether) methacrylate bone adhesives: setting, degradation and drug release considerations.

    Science.gov (United States)

    Zhao, Xin; Olsen, Irwin; Pratten, Jonathan; Knowles, Jonathan C; Young, Anne M

    2011-09-01

    This study has investigated novel bone adhesives consisting of fluid photo-polymerizable poly(lactide-co-propylene glycol-co-lactide)dimethacrylate (PGLA-DMA) mixed with systematically varying fillers of β-tricalcium phosphate (β-TCP) and monocalcium phosphate monohydrate (MCPM), for the delivery of an antibacterial drug chlorhexidine (CHX). All formulations were found to polymerize fully within 200 s after exposure to blue light. In addition, water sorption by the polymerized materials catalyzed varying filler conversion to dicalcium phosphate (DCP) (i.e. brushite and monetite). With greater DCP levels, faster degradation was observed. Moreover, increase in total filler content enhanced CHX release, associated with higher antibacterial activity. These findings thus suggest that such rapid-setting and degradable adhesives with controllable drug delivery property could have potential clinical value as bone adhesives with antibacterial activity.

  10. A review paper on biomimetic calcium phosphate coatings

    OpenAIRE

    Lin, X.; De Groot,, P.A.J.; Wang, D.; Hu, Q; Wismeijer, D.; Liu, Y

    2015-01-01

    Biomimetic calcium phosphate coatings have been developed for bone regeneration and repair because of their biocompatibility, osteoconductivity, and easy preparation. They can be rendered osteoinductive by incorporating an osteogenic agent, such as bone morphogenetic protein 2 (BMP-2), into the crystalline lattice work in physiological situations. The biomimetic calcium phosphate coating enables a controlled, slow and local release of BMP-2 when it undergoes cell mediated coating degradation ...

  11. Calcium phosphate-based ceramic and composite materials for medicine

    International Nuclear Information System (INIS)

    The topical problems in chemistry and technology of materials based on calcium phosphates aimed at both the replacement of damaged bone tissue and its regeneration are discussed. Specific features of the synthesis of nanocrystalline powders and the fabrication of ceramic implants are described. Advances in the development of porous scaffolds from resorbable and osteoconductive calcium phosphates and of hybrid composites that form the basis of bone tissue engineering are considered.

  12. Increased osteoinductivity and mineralization by minimal concentration of bone morphogenetic protein-2 loaded onto biphasic calcium phosphate in a rabbit sinus

    Science.gov (United States)

    2016-01-01

    Purpose The purpose of the present study was to evaluate the effectiveness of a minimal concentration of bone morphogenetic protein-2 (BMP-2) in terms of quantitative and qualitative analyses of newly formed bone in a rabbit maxillary sinus model. Methods In 7 rabbits, sinus windows were prepared bilaterally. Biphasic calcium phosphate (BCP) loaded with 0.05 mg/mL BMP-2 was grafted into one sinus (the BMP group) and saline-soaked BCP was placed into the other (the control group) in each animal. The animals were allowed an 8-week healing period before being sacrificed. Specimens including the augmented area and surrounding tissues were then removed and evaluated both radiographically and histologically. Results There was a difference in the mineralization of new bone between the groups. In the BMP group, the greater part of the new bone consisted of mature lamellar bone with an evident trabecular pattern, whereas the control group showed mostly woven bone, consisting only partially of lamellar bone. Histometrically, the area of new bone was significantly greater (4.55±1.35 mm2 vs. 2.99±0.86 mm2) in the BMP group than in the control group (Pmineralization in a rabbit sinus model using a BCP carrier. PMID:27800217

  13. Analysis of bone formation on porous and calcium phosphate-coated acetabular cups: a randomised clinical [18F]fluoride PET study.

    Science.gov (United States)

    Ullmark, Gösta; Sörensen, Jens; Nilsson, Olle

    2012-01-01

    We present a study using Fluoride-Positron Emission Tomography (F-PET/CT) to analyse new bone formation in periacetabular bone adjacent to press fit cups following THA. In 16 THA (8 patients) with bilateral hip osteoarthritis simultaneous bilateral total hip arthroplasty (THA) was performed, employing electrochemically applied calcium phosphate coated (HA) cups or porous-coated (PC) cups allocated at random to compare the two sides. A reference group of 13 individuals with a normal healthy hip was used to determine 'normal' bone metabolism. [18F]fluoride -PET/CT was used to analyze bone formation adjacent to the cups 1 week, 4 months and 12 months after surgery. Clinical and radiographic evaluation was performed preoperatively, postoperatively and at 2 years. Bone forming activity had a mean of 5.71, 4.69 and 3.47 SUV around the HA- and 5.04, 4.80 and 3.50 SUV around the PC-cups at 1 week, 4 months and 12 months respectively. Normal bone metabolism was 3.68 SUV. After 1 year activity had declined to normal levels for both groups. The clinical results were good in all cases. HA coating resulted in higher uptake indicating higher bone forming activity after 1 week. F-PET/CT is a valuable tool to analyse bone formation and secondary stabilisation of an acetabular cup. PMID:22547382

  14. Calcium phosphate ceramics in drug delivery

    Science.gov (United States)

    Bose, Susmita; Tarafder, Solaiman; Edgington, Joe; Bandyopadhyay, Amit

    2011-04-01

    Calcium phosphate (CaP) particulates, cements and scaffolds have attracted significant interest as drug delivery vehicles. CaP systems, including both hydroxyapaptite and tricalcium phosphates, possess variable stoichiometry, functionality and dissolution properties which make them suitable for cellular delivery. Their chemical similarity to bone and thus biocompatibility, as well as variable surface charge density contribute to their controlled release properties. Among specific research areas, nanoparticle size, morphology, surface area due to porosity, and chemistry controlled release kinetics are the most active. This article discusses CaP systems in their particulate, cements, and scaffold forms for drug, protein, and growth factor delivery toward orthopedic and dental applications.

  15. Calcium Phosphates as Bone Substitute for Dental Implant Surgery%口腔种植中磷酸钙类骨替代材料的应用

    Institute of Scientific and Technical Information of China (English)

    陈卓凡; 刘泉; Matinlinna JP

    2016-01-01

    在口腔种植手术中,磷酸钙类的骨替代材料已经被广泛应用于骨修复、骨增量和重建.了解此类材料的基础性能,对于一个种植医生来说是非常重要的,但初学者可能无法完全掌握.因此,本文对异种来源和人工合成的两类骨移植材料的特点,进行了全面总结评述.尽管部分材料显示了优良的生物效应,但目前磷酸钙类的骨替代材料仍有巨大的改进提升空间.%Calcium phosphate-based bone substitutes have been widely used for bone repair, augmentation and recon-struction in dental implant surgery. The basic properties of such materials are undoubtedly of importance, but may not be comprehensively understood by practitioners. Hence, the properties of two major groups, xenogenic and alloplastic grafting materials, have been reviewed and discussed in this article. It appears that more work is needed to improve the perfor-mance of the current calcium phosphate-based bone substitutes, although some of them have been showing outstanding bi-ological response.

  16. Balancing mechanical strength with bioactivity in chitosan-calcium phosphate 3D microsphere scaffolds for bone tissue engineering: air- vs. freeze-drying processes.

    Science.gov (United States)

    Nguyen, D T; McCanless, J D; Mecwan, M M; Noblett, A P; Haggard, W O; Smith, R A; Bumgardner, J D

    2013-01-01

    The objective of this study was to evaluate the potential benefit of 3D composite scaffolds composed of chitosan and calcium phosphate for bone tissue engineering. Additionally, incorporation of mechanically weak lyophilized microspheres within those air-dried (AD) was considered for enhanced bioactivity. AD microsphere, alone, and air- and freeze-dried microsphere (FDAD) 3D scaffolds were evaluated in vitro using a 28-day osteogenic culture model with the Saos-2 cell line. Mechanical testing, quantitative microscopy, and lysozyme-driven enzymatic degradation of the scaffolds were also studied. FDAD scaffold showed a higher concentration (p mechanical strength was sacrificed through introduction of the less stiff, porous FD spheres.

  17. Calcium phosphate fibers coated with collagen: In vivo evaluation of the effects on bone repair.

    Science.gov (United States)

    Ueno, Fabio Roberto; Kido, Hueliton Wilian; Granito, Renata Neves; Gabbai-Armelin, Paulo Roberto; Magri, Angela Maria Paiva; Fernandes, Kelly Rosseti; da Silva, Antonio Carlos; Braga, Francisco José Correa; Renno, Ana Claudia Muniz

    2016-08-12

    The aim of this study was to assess the characteristics of the CaP/Col composites, in powder and fiber form, via scanning electron microscopy (SEM), pH and calcium release evaluation after immersion in SBF and to evaluate the performance of these materials on the bone repair process in a tibial bone defect model. For this, four different formulations (CaP powder - CaPp, CaP powder with collagen - CaPp/Col, CaP fibers - CaPf and CaP fibers with collagen - CaPf/Col) were developed. SEM images indicated that both material forms were successfully coated with collagen and that CaPp and CaPf presented HCA precursor crystals on their surface. Although presenting different forms, FTIR analysis indicated that CaPp and CaPf maintained the characteristic peaks for this class of material. Additionally, the calcium assay study demonstrated a higher Ca uptake for CaPp compared to CaPf for up to 5 days. Furthermore, pH measurements revealed that the collagen coating prevented the acidification of the medium, leading to higher pH values for CaPp/Col and CaPf/Col. The histological analysis showed that CaPf/Col demonstrated a higher amount of newly formed bone in the region of the defect and a reduced presence of material. In summary, the results indicated that the fibrous CaP enriched with the organic part (collagen) glassy scaffold presented good degradability and bone-forming properties and also supported Runx2 and RANKL expression. These results show that the present CaP/Col fibrous composite may be used as a bone graft for inducing bone repair. PMID:27567780

  18. Influence of physico-chemical material characteristics on staphylococcal biofilm formation – A qualitative and quantitative in vitro analysis of five different calcium phosphate bone grafts

    Directory of Open Access Journals (Sweden)

    M Clauss

    2014-07-01

    Full Text Available Various compositions of synthetic calcium phosphates (CaP have been proposed and their use has considerably increased over the past decades. Besides differences in physico-chemical properties, resorption and osseointegration, artificial CaP bone graft might differ in their resistance against biofilm formation. We investigated standardised cylinders of 5 different CaP bone grafts (cyclOS, chronOS (both β-TCP (tricalcium phosphate, dicalcium phosphate (DCP, calcium-deficient hydroxyapatite (CDHA and α-TCP. Various physico-chemical characterisations e.g., geometrical density, porosity, and specific surface area were investigated. Biofilm formation was carried out in tryptic soy broth (TSB and human serum (SE using Staphylococcus aureus (ATCC 29213 and S. epidermidis RP62A (ATCC 35984. The amount of biofilm was analysed by an established protocol using sonication and microcalorimetry. Physico-chemical characterisation showed marked differences concerning macro- and micropore size, specific surface area and porosity accessible to bacteria between the 5 scaffolds. Biofilm formation was found on all scaffolds and was comparable for α-TCP, chronOS, CDHA and DCP at corresponding time points when the scaffolds were incubated with the same germ and/or growth media, but much lower for cyclOS. This is peculiar because cyclOS had an intermediate porosity, mean pore size, specific surface area, and porosity accessible to bacteria. Our results suggest that biofilm formation is not influenced by a single physico-chemical parameter alone but is a multi-step process influenced by several factors in parallel. Transfer from in vitro data to clinical situations is difficult; thus, advocating the use of cyclOS scaffolds over the four other CaP bone grafts in clinical situations with a high risk of infection cannot be clearly supported based on our data.

  19. Influence of physico-chemical material characteristics on staphylococcal biofilm formation--a qualitative and quantitative in vitro analysis of five different calcium phosphate bone grafts.

    Science.gov (United States)

    Clauss, M; Furustrand Tafin, U; Betrisey, B; van Garderen, N; Trampuz, A; Ilchmann, T; Bohner, M

    2014-07-18

    Various compositions of synthetic calcium phosphates (CaP) have been proposed and their use has considerably increased over the past decades. Besides differences in physico-chemical properties, resorption and osseointegration, artificial CaP bone graft might differ in their resistance against biofilm formation. We investigated standardised cylinders of 5 different CaP bone grafts (cyclOS, chronOS (both β-TCP (tricalcium phosphate)), dicalcium phosphate (DCP), calcium-deficient hydroxyapatite (CDHA) and α-TCP). Various physico-chemical characterisations e.g., geometrical density, porosity, and specific surface area were investigated. Biofilm formation was carried out in tryptic soy broth (TSB) and human serum (SE) using Staphylococcus aureus (ATCC 29213) and S. epidermidis RP62A (ATCC 35984). The amount of biofilm was analysed by an established protocol using sonication and microcalorimetry. Physico-chemical characterisation showed marked differences concerning macro- and micropore size, specific surface area and porosity accessible to bacteria between the 5 scaffolds. Biofilm formation was found on all scaffolds and was comparable for α-TCP, chronOS, CDHA and DCP at corresponding time points when the scaffolds were incubated with the same germ and/or growth media, but much lower for cyclOS. This is peculiar because cyclOS had an intermediate porosity, mean pore size, specific surface area, and porosity accessible to bacteria. Our results suggest that biofilm formation is not influenced by a single physico-chemical parameter alone but is a multi-step process influenced by several factors in parallel. Transfer from in vitro data to clinical situations is difficult; thus, advocating the use of cyclOS scaffolds over the four other CaP bone grafts in clinical situations with a high risk of infection cannot be clearly supported based on our data.

  20. 21 CFR 582.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.1217 Section 582.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  1. 21 CFR 182.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.1217 Section 182.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  2. 21 CFR 582.5217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic)....

  3. Comparison of calcium carbonate and aluminium hydroxide as phosphate binders on biochemical bone markers, PTH(1-84), and bone mineral content in dialysis patients

    DEFF Research Database (Denmark)

    Jespersen, B; Jensen, J D; Nielsen, H K;

    1991-01-01

    Bone mineral content, estimated by single-photon absorptiometry of the forearm, serum values of intact parathyroid hormone (PTH(1-84], osteocalcin, alkaline phosphatase, 1,25-dihydroxycholecalciferol (1,25(OH)2D3), and aluminium were determined during treatment with calcium carbonate (CaCO3...

  4. Fabrications of zinc-releasing biocement combining zinc calcium phosphate to calcium phosphate cement.

    Science.gov (United States)

    Horiuchi, Shinya; Hiasa, Masahiro; Yasue, Akihiro; Sekine, Kazumitsu; Hamada, Kenichi; Asaoka, Kenzo; Tanaka, Eiji

    2014-01-01

    Recently, zinc-releasing bioceramics have been the focus of much attention owing to their bone-forming ability. Thus, some types of zinc-containing calcium phosphate (e.g., zinc-doped tricalcium phosphate and zinc-substituted hydroxyapatite) are examined and their osteoblastic cell responses determined. In this investigation, we studied the effects of zinc calcium phosphate (ZCP) derived from zinc phosphate incorporated into calcium phosphate cement (CPC) in terms of its setting reaction and MC3T3-E1 osteoblast-like cell responses. Compositional analysis by powder X-ray diffraction analysis revealed that HAP crystals were precipitated in the CPC containing 10 or 30wt% ZCP after successfully hardening. However, the crystal growth observed by scanning electron microscopy was delayed in the presence of additional ZCP. These findings indicate that the additional zinc inhibits crystal growth and the conversion of CPC to the HAP crystals. The proliferation of the cells and alkaline phosphatase (ALP) activity were enhanced when 10wt% ZCP was added to CPC. Taken together, ZCP added CPC at an appropriate fraction has a potent promotional effect on bone substitute biomaterials. PMID:24090874

  5. 21 CFR 182.8217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic). (b) Conditions of use. This...

  6. In vitro bone formation by human marrow cell culture on the surface of zinc-releasing calcium phosphate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ikeuchi, M.; Noshi, T.; Horiuchi, K.; Yamamoto, K.; Sugimura, M. [Nara Medical Univ., Kashihara (Japan). Dept. of Oral and Maxillofacial Surgery; Dohi, Y. [Nara Medical Univ., Kashihara (Japan). Dept. of Public Health; Ohgushi, H. [Nara Medical Univ., Kashihara (Japan). Dept. of Orthopedics; Ito, A. [National Inst. for Advanced Interdisciplinary Research, MITI, Ibaraki (Japan)

    2001-07-01

    We examined the effect of zinc on the osteogenic differentiation of cultured human marrow cells on the surface of zinc-releasing TCP/HAP (Zn-TCP/HAP) ceramics in the shape of a disk. Three ml of human bone marrow harvested from the ilium was cultured in a medium containing 15% fetal bovine serum to reach confluent. After trypsinization, the cells were seeded at 20 x 10{sup 3} cells/16 mm {phi} on Falcon tissue wells with the ceramic disks (TCP/HAP containing 0, 0.32, 0.42, 0.63, 0.88 and 1.26 wt% Zn). After 2 weeks of subculture in the presence of {beta}-glycerophosphate, vitamin C phosphate, and dexamethasone (Dex), the cells were stained for alkaline phosphatase (ALP). The ALP stain was strengthened as zinc content of the disk increased. The data demonstrated that Zn-TCP/HAP influenced cell differentiation in human marrow cell culture and resulted in high osteoblastic activity. Furthermore, ALP activities of the cell layer significantly increased depending on zinc content of the disk in the presence of Dex. These results indicate that the surface of Zn-TCP/HAP stimulates osteogenic differentiation in human cultured marrow cells as well as in rat ones. Thus, Zn-TCP/HAP ceramics are expected to be useful materials for bone reconstructive surgery. (orig.)

  7. Enhanced bone forming ability of SLA-treated Ti coated with a calcium phosphate thin film formed by e-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeongil [Restorative Dentistry, School of Dental Medicine, University at Buffalo, NY 14214 (United States); Choi, Seong-Ho [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Chung, Sung-Min; Li, Long-Hao [Dentium Clinic Implantium Institute, Seoul 135-879 (Korea, Republic of); Lee, In-Seop, E-mail: inseop@yonsei.ac.k [Atomic-Scale Surface Science Research Center, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2010-08-01

    With an electron-beam evaporation process, a calcium phosphate (Ca-P) thin film of {approx}500 nm thick was deposited on sand blasted with large grits and acid etched (SLA) Ti without changing the typical morphology of the SLA surface. Dissolution behavior was investigated by measuring the amount of dissolved phosphate ions with ion chromatography after immersing the SLA Ti sample coated with a Ca-P film in 1 ml de-ionized water maintained at 37 {sup 0}C for different periods of soaking time, and the surface morphology was observed with field emission scanning electron microscopy. The amount of phosphate ions increased quickly right after immersion but began to decrease after 2 days of immersion by redeposition with Ca ions as apatite, and the amount of biomimetic apatite increased with the extended soaking time. The Saos-2 cell was more attached on the coated surface, and the in vivo evaluation was that the Ca-P deposited SLA implant greatly improved the new bone formation ability.

  8. Enhanced bone forming ability of SLA-treated Ti coated with a calcium phosphate thin film formed by e-beam evaporation.

    Science.gov (United States)

    Kim, Hyeongil; Choi, Seong-Ho; Chung, Sung-Min; Li, Long-Hao; Lee, In-Seop

    2010-08-01

    With an electron-beam evaporation process, a calcium phosphate (Ca-P) thin film of approximately 500 nm thick was deposited on sand blasted with large grits and acid etched (SLA) Ti without changing the typical morphology of the SLA surface. Dissolution behavior was investigated by measuring the amount of dissolved phosphate ions with ion chromatography after immersing the SLA Ti sample coated with a Ca-P film in 1 ml de-ionized water maintained at 37 degrees C for different periods of soaking time, and the surface morphology was observed with field emission scanning electron microscopy. The amount of phosphate ions increased quickly right after immersion but began to decrease after 2 days of immersion by redeposition with Ca ions as apatite, and the amount of biomimetic apatite increased with the extended soaking time. The Saos-2 cell was more attached on the coated surface, and the in vivo evaluation was that the Ca-P deposited SLA implant greatly improved the new bone formation ability.

  9. Enhanced bone forming ability of SLA-treated Ti coated with a calcium phosphate thin film formed by e-beam evaporation

    International Nuclear Information System (INIS)

    With an electron-beam evaporation process, a calcium phosphate (Ca-P) thin film of ∼500 nm thick was deposited on sand blasted with large grits and acid etched (SLA) Ti without changing the typical morphology of the SLA surface. Dissolution behavior was investigated by measuring the amount of dissolved phosphate ions with ion chromatography after immersing the SLA Ti sample coated with a Ca-P film in 1 ml de-ionized water maintained at 37 0C for different periods of soaking time, and the surface morphology was observed with field emission scanning electron microscopy. The amount of phosphate ions increased quickly right after immersion but began to decrease after 2 days of immersion by redeposition with Ca ions as apatite, and the amount of biomimetic apatite increased with the extended soaking time. The Saos-2 cell was more attached on the coated surface, and the in vivo evaluation was that the Ca-P deposited SLA implant greatly improved the new bone formation ability.

  10. Combined Effect of a Microporous Layer and Type I Collagen Coating on a Biphasic Calcium Phosphate Scaffold for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Mun-Hwan Lee

    2015-03-01

    Full Text Available In this study, type I collagen was coated onto unmodified and modified microporous biphasic calcium phosphate (BCP scaffolds. Surface characterization using a scanning electron microscope (SEM and a surface goniometer confirmed the modification of the BCP coating. The quantity of the collagen coating was investigated using Sirius Red staining, and quantitative assessment of the collagen coating showed no significant differences between the two groups. MG63 cells were used to evaluate cell proliferation and ALP activity on the modified BCP scaffolds. The modified microporous surfaces showed low contact angles and large surface areas, which enhanced cell spreading and proliferation. Coating of the BCP scaffolds with type I collagen led to enhanced cell-material interactions and improved MG63 functions, such as spreading, proliferation, and differentiation. The micropore/collagen-coated scaffold showed the highest rate of cell response. These results indicate that a combination of micropores and collagen enhances cellular function on bioengineered bone allograft tissue.

  11. Vitamin D, Calcium, and Bone Health

    Science.gov (United States)

    ... Balance › Vitamin D, Calcium, and Bone Health Vitamin D, Calcium, and Bone Health March 2012 Download PDFs ... helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin D ...

  12. Calcium phosphate cements properties with polymers addition

    International Nuclear Information System (INIS)

    Calcium phosphate cements (CPC) have attracted great interest to use in orthopedics and dentistry as replacements for damaged parts of the skeletal system, showing good biocompatibility and osseointegration, allowing its use as bone graft. Several studies have shown that the addition of polymer additives have a strong influence on the cement properties. The low mechanical strength is the main obstacle to greater use of CPC as an implant material. The objective of this study was to evaluate properties of a cement based on α-tricalcium phosphate (α-TCP), added polymers. PVA (10%, 8%, 6%), sodium alginate (2%) and polyacrylate ammonia (3%), all in weight, were added to the synthesized α-TCP powder. The samples were molded and evaluated for density, porosity in vitro test (Simulated Body Fluid), crystalline phases and mechanical strength. The results show increased the mechanical properties of the cement when added these polymers

  13. Evaluation of an injectable silk fibroin enhanced calcium phosphate cement loaded with human recombinant bone morphogenetic protein-2 in ovine lumbar interbody fusion.

    Science.gov (United States)

    Gu, Yong; Chen, Liang; Yang, Hui-Lin; Luo, Zong-Ping; Tang, Tian-Si

    2011-05-01

    The objective of this study was to investigate the efficacy of an injectable calcium phosphate cement/silk fibroin/human recombinant bone morphogenetic protein-2 composite (CPC/SF/rhBMP-2) in an ovine interbody fusion model. Twenty-four mature sheep underwent anterior lumbar interbody fusion at the levels of L1/2, L3/4, and L5/6 with random implantation of CPC/SF, CPC/rhBMP-2, CPC/SF/rhBMP-2, or autogenous iliac bone. After the sheep were sacrificed, the fusion segments were evaluated by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. The fusion rates of CPC/SF/rhBMP-2 were 55.56% and 77.78% at 6 and 12 months, respectively. The fusion was superior to all the biomaterial grafts in stiffness, and reached the same stiffness as the autograft at 12 months. The new bone formation was less than autograft at 6 months, but similar with that at 12 months. However, the ceramic residue volume of CPC/SF/rhBMP-2 was significantly decreased compared with CPC/SF and CPC/rhBMP-2 at both times. The results indicated that CPC/SF/rhBMP-2 composite had excellent osteoconduction and osteoinduction, and balanced degradation and osteogenesis.

  14. Children's Bone Health and Calcium

    Science.gov (United States)

    ... Trials Resources and Publications Children's Bone Health and Calcium: Condition Information Skip sharing on social media links ... straight, walk, run, and lead an active life. Calcium is one of the key dietary building blocks ...

  15. A review of nanocrystalline calcium phosphate scaffold in bone tissue engineering%纳米磷酸钙骨组织工程支架材料研究进展

    Institute of Scientific and Technical Information of China (English)

    李波; 经又治; 赵海全; 周冠瑜; 况敏; 郭弦

    2011-01-01

    With the development of nanotechnology and biotechnology, many experts have fabricated a serial of novel bone scaffolds. To better understand the advantages of nano biomaterials and guide the preparation of no-vel bone materials, this review presents the recent advances of nanocrystalline calcium phosphate-related bone scaffold, especially on the preparation method, properties and application of nano calcium phosphate ceramics, calcium phosphate composite ceramics and nano calcium phosphate/polymers composite, and summary the shortcomings and research direction of these methods.%随着纳米和生物技术的进步,国内外学者制备了一系列新型的骨组织工程支架材料.为了更好地认识纳米生物材料的优点和指导制备新型的骨组织工程支架材料,综述了近年来纳米磷酸钙相关支架材料研究进展,着重介绍了纳米磷酸钙陶瓷、纳米磷酸钙复合陶瓷以及纳米磷酸钙/聚合物复合材料制备方法、性能和应用,并总结了各类方法的不足之处和将来发展的趋势.

  16. Hybrid calcium phosphate coatings for implants

    Science.gov (United States)

    Malchikhina, Alena I.; Shesterikov, Evgeny V.; Bolbasov, Evgeny N.; Ignatov, Viktor P.; Tverdokhlebov, Sergei I.

    2016-08-01

    Monophasic biomaterials cannot provide all the necessary functions of bones or other calcined tissues. It is necessary to create for cancer patients the multiphase materials with the structure and composition simulating the natural bone. Such materials are classified as hybrid, obtained by a combination of chemically different components. The paper presents the physical, chemical and biological studies of coatings produced by hybrid technologies (HT), which combine primer layer and calcium phosphate (CaP) coating. The first HT type combines the method of vacuum arc titanium primer layer deposition on a stainless steel substrate with the following micro-arc oxidation (MAO) in phosphoric acid solution with addition of calcium compounds to achieve high supersaturated state. MAO CaP coatings feature high porosity (2-8%, pore size 5-7 µm) and surface morphology with the thickness greater than 5 µm. The thickness of Ti primer layer is 5-40 µm. Amorphous MAO CaP coating micro-hardness was measured at maximum normal load Fmax = 300 mN. It was 3.1 ± 0.8 GPa, surface layer elasticity modulus E = 110 ± 20 GPa, roughness Ra = 0.9 ± 0.1 µm, Rz = 7.5 ± 0.2 µm, which is less than the titanium primer layer roughness. Hybrid MAO CaP coating is biocompatible, able to form calcium phosphates from supersaturated body fluid (SBF) solution and also stimulates osteoinduction processes. The second HT type includes the oxide layer formation by thermal oxidation and then CaP target radio frequency magnetron sputtering (RFMS). Oxide-RFMS CaP coating is a thin dense coating with good adhesion to the substrate material, which can be used for metal implants. The RFMS CaP coating has thickness 1.6 ± 0.1 µm and consists of main target elements calcium and phosphorus and Ca/P ratio 2.4. The second HT type can form calcium phosphates from SBF solution. In vivo study shows that hybrid RFMS CaP coating is biocompatible and produces fibrointegration processes.

  17. Osteoinduction and survival of osteoblasts and bone-marrow stromal cells in 3D biphasic calcium phosphate scaffolds under static and dynamic culture conditions.

    Science.gov (United States)

    Rath, Subha N; Strobel, Leonie A; Arkudas, Andreas; Beier, Justus P; Maier, Anne-Kathrin; Greil, Peter; Horch, Raymund E; Kneser, Ulrich

    2012-10-01

    In many tissue engineering approaches, the basic difference between in vitro and in vivo conditions for cells within three-dimensional (3D) constructs is the nutrition flow dynamics. To achieve comparable results in vitro, bioreactors are advised for improved cell survival, as they are able to provide a controlled flow through the scaffold. We hypothesize that a bioreactor would enhance long-term differentiation conditions of osteogenic cells in 3D scaffolds. To achieve this either primary rat osteoblasts or bone marrow stromal cells (BMSC) were implanted on uniform-sized biphasic calcium phosphate (BCP) scaffolds produced by a 3D printing method. Three types of culture conditions were applied: static culture without osteoinduction (Group A); static culture with osteoinduction (Group B); dynamic culture with osteoinduction (Group C). After 3 and 6 weeks, the scaffolds were analysed by alkaline phosphatase (ALP), dsDNA amount, SEM, fluorescent labelled live-dead assay, and real-time RT-PCR in addition to weekly alamarBlue assays. With osteoinduction, increased ALP values and calcium deposition are observed; however, under static conditions, a significant decrease in the cell number on the biomaterial is observed. Interestingly, the bioreactor system not only reversed the decreased cell numbers but also increased their differentiation potential. We conclude from this study that a continuous flow bioreactor not only preserves the number of osteogenic cells but also keeps their differentiation ability in balance providing a suitable cell-seeded scaffold product for applications in regenerative medicine.

  18. Evaluation of bone regenerative capacity in rats claverial bone defect using platelet rich fibrin with and without beta tri calcium phosphate bone graft material

    Directory of Open Access Journals (Sweden)

    Walid Ahmed Abdullah

    2016-07-01

    Conclusion: The addition of β-TCP to PRF significantly improved bone regeneration in the first 2 weeks after surgery. Although the differences between results with and without the addition of β-TCP to PRF were statistically insignificant from weeks 3 to 6, it was nevertheless apparent that the group receiving the combination showed better results. We suggest a synergistic mechanism for this effect.

  19. Effects of Nickel on Calcium Phosphate Formation

    Science.gov (United States)

    Guerra-López, J.; González, R.; Gómez, A.; Pomés, R.; Punte, G.; Della Védova, C. O.

    2000-05-01

    We have investigated the effect of nickel on calcium phosphate formation from aqueous solutions. The calcium phosphates prepared under different reaction conditions (pH, temperature, and nickel concentration) were characterized by X-ray diffraction, FTIR spectroscopy, and chemical analysis. The apatite compounds were also studied thermogravimetrically. From the combined results of the techniques employed we have determined that nickel favors the formation of brushite and amorphous calcium phosphate. We have found, as well, that the presence of nickel in the solution inhibits calcium hydroxyapatite (CaHAP) and octacalcium phosphate formation. However in the synthesis performed at basic pH and 95°C the apatitic phase (HAP) could be obtained. The present results suggest that the presence of nickel may modify the precipitation of oral calcium phosphate.

  20. Characterization of cement calcium phosphate for use dental

    International Nuclear Information System (INIS)

    Calcium phosphates are interesting biological and medical attention due to its occurrence in different animal species and humans. Ceramics based on calcium phosphate in the form of implants or porous particulate materials, have proven to be suitable replacements for bone tissue when they are only subjected to small mechanical stresses. Was obtained research laboratory DEMA/UFCG a calcium phosphate phase. The goal is to characterize the material by X-ray diffraction (XRD) in order to analyze what the phases and infrared spectroscopy (FTIR) to identify the absorption bands of the bonding characteristic. Was identified by XRD phase present in the sample is hydroxyapatite Ca/P 1.67. In infrared spectroscopy has absorption bands characteristic of the phosphate group at 1032 cm1 region. (author)

  1. Regulation of physicochemical properties, osteogenesis activity, and fibroblast growth factor-2 release ability of β-tricalcium phosphate for bone cement by calcium silicate

    Energy Technology Data Exchange (ETDEWEB)

    Su, Ching-Chuan [Antai Medical Care Cooperation Antai Tian-Sheng Memorial Hospital, Pingtung, Taiwan (China); Kao, Chia-Tze; Hung, Chi-Jr [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chen, Yi-Jyun [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Dental Department, Taichung Hospital, Ministry of Health and Welfare, Taichung City, Taiwan (China); Huang, Tsui-Hsien, E-mail: thh@csmu.edu.tw [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Institute of Oral Science, Chung Shan Medical University, Taichung, Taiwan (China)

    2014-04-01

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of bone-like apatite, the diametral tensile strength, and weight loss of composites were considered before and after immersion in simulated body fluid (SBF). In addition, we also examined the effects of fibroblast growth factor-2 (FGF-2) released from β-TCP/CS composites and in vitro human dental pulp cell (hDPC) and studied its behavior. The results showed that the apatite deposition ability of the β-TCP/CS composites was enhanced as the CS content was increased. For composites with more than 50% CS contents, the samples were completely covered by a dense bone-like apatite layer. At the end of the immersion point, weight losses of 19%, 24%, 33%, 42%, and 51% were observed for the composites containing 0%, 30%, 50%, 70% and 100% β-TCP cements, respectively. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 70%, the amount of cells and osteogenesis protein of hDPCs was stimulated by FGF-2 released from β-TCP/CS composites. The combination of FGF-2 in degradation of β-TCP and osteogenesis of CS gives a strong reason to believe that these calcium-based composite cements may prove to be promising bone repair materials. - Highlights: • CS improved physicochemical properties and osteogenic activity of β-TCP. • The higher the CS in the cement, the shorter the setting time and the higher the DTS. • The cell behavior was stimulated by FGF-2 released from composite containing 50% CS. • β-TCP/CS composite with FGF-2 has optimal properties for

  2. Regulation of physicochemical properties, osteogenesis activity, and fibroblast growth factor-2 release ability of β-tricalcium phosphate for bone cement by calcium silicate

    International Nuclear Information System (INIS)

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of bone-like apatite, the diametral tensile strength, and weight loss of composites were considered before and after immersion in simulated body fluid (SBF). In addition, we also examined the effects of fibroblast growth factor-2 (FGF-2) released from β-TCP/CS composites and in vitro human dental pulp cell (hDPC) and studied its behavior. The results showed that the apatite deposition ability of the β-TCP/CS composites was enhanced as the CS content was increased. For composites with more than 50% CS contents, the samples were completely covered by a dense bone-like apatite layer. At the end of the immersion point, weight losses of 19%, 24%, 33%, 42%, and 51% were observed for the composites containing 0%, 30%, 50%, 70% and 100% β-TCP cements, respectively. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 70%, the amount of cells and osteogenesis protein of hDPCs was stimulated by FGF-2 released from β-TCP/CS composites. The combination of FGF-2 in degradation of β-TCP and osteogenesis of CS gives a strong reason to believe that these calcium-based composite cements may prove to be promising bone repair materials. - Highlights: • CS improved physicochemical properties and osteogenic activity of β-TCP. • The higher the CS in the cement, the shorter the setting time and the higher the DTS. • The cell behavior was stimulated by FGF-2 released from composite containing 50% CS. • β-TCP/CS composite with FGF-2 has optimal properties for

  3. Lumbar interbody fusion with porous biphasic calcium phosphate enhanced by recombinant bone morphogenetic protein-2/silk fibroin sustained-released microsphere: an experimental study on sheep model.

    Science.gov (United States)

    Chen, Liang; Liu, Hai-Long; Gu, Yong; Feng, Yu; Yang, Hui-Lin

    2015-03-01

    Biphasic calcium phosphate (BCP) has been investigated extensively as a bone substitute nowadays. However, the bone formation capacity of BCP is limited owing to lack of osteoinduction. Silk fibroin (SF) has a structure similar to type I collagen, and could be developed to a microsphere for the sustained-release of rhBMP-2. In our previous report, bioactivity of BCP could be enhanced by rhBMP-2/SF microsphere (containing 0.5 µg rhBMP-2) in vitro. However, the bone regeneration performance of the composite in vivo was not investigated. Thus, the purpose of this study was to evaluate the efficacy of BCP/rhBMP-2/SF in a sheep lumbar fusion model. A BCP and rhBMP-2/SF microsphere was developed, and then was integrated into a BCP/rhBMP-2/SF composite. BCP, BCP/rhBMP-2 and BCP/rhBMP-2/SF were implanted randomly into the disc spaces of 30 sheep at the levels of L1/2, L3/4 and L5/6. After sacrificed, the fusion segments were evaluated by manual palpation, CT scan, biomechanical testing and histology at 3 and 6 months, respectively. The composite demonstrated a burst-release of rhBMP-2 (39.1 ± 2.8 %) on the initial 4 days and a sustained-release (accumulative 81.3 ± 4.9 %) for more than 28 days. The fusion rates, semi-quantitative CT scores, fusion stiffness in bending in all directions and histologic scores of BCP/rhBMP-2/SF were significantly greater than BCP and BCP/rhBMP-2 at each time point, respectively (P sheep using BCP constructs.

  4. The Transformation of Calcium Phosphate Bioceramics in Vivo

    Institute of Scientific and Technical Information of China (English)

    DAI Hong-lian; CAO Xian-ying; LI Xiao-xi; YAN Yu-hua; LI Shi-pu

    2003-01-01

    To study the transformation process of calcium phosphate bioceramic in vivo,biodegradable porous β-tricalcium phosphate ceramics (β-TCP) were used in this experiment. The materials (φ5×8mm) were implanted in the tibia of rabbits. The β-TCP ceramics with bone tissue were retrieved and treated for histology, and then observed by using a scanning electron microscope (SEM) and an electron probe X-ray microanalyzer (EMPA) every month. The results show that β-TCP ceramics bond to bone directly,new bones are forming and maturing with materials continuous degrading,and the materials are nearly replaced by the formed bone finally.Parts of the materials were degraded,absorpted and recrystallized,the others dispersped on the cancellous bone and the Haversian lamella with an irregular arrangement incorporating in bone formation directly by remodeling structure.

  5. Bone regeneration related to calcium phosphate-coated implants in osteoporotic animal models: a meta-analysis

    NARCIS (Netherlands)

    Alghamdi, H.S.; Junker, R.; Bronkhorst, E.M.; Jansen, J.A.

    2012-01-01

    BACKGROUND: Osteoporosis is a frequent human metabolic bone disorder. Prospectively, global ageing of populations will lead to a major increase of subjects being diagnosed with osteoporosis and in need for dental rehabilitation. However, as local osteoporosis of the jaws affects bone quantity and qu

  6. Towards injectable cell-based tissue-engineered bone : The effect of different calcium phosphate microparticles and pre-culturing

    NARCIS (Netherlands)

    Persson, C; Johansson, G; Dhert, WJA; Kruyt, Moyo C.; de Bruijn, Joost D.

    2006-01-01

    Bone tissue engineering by combining bone marrow stromal cells (BMSCs) with a porous scaffold is a promising technology. Current major challenges are to upscale the technique for clinical application and to improve the handling characteristics. With respect to minimal invasive surgery, moldable and/

  7. Calcium and bones (image)

    Science.gov (United States)

    Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...

  8. Renal control of calcium, phosphate, and magnesium homeostasis.

    Science.gov (United States)

    Blaine, Judith; Chonchol, Michel; Levi, Moshe

    2015-07-01

    Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys.

  9. Toward accelerated bone regeneration by altering poly(D,L-lactic-co-glycolic) acid porogen content in calcium phosphate cement.

    Science.gov (United States)

    van Houdt, C I A; Preethanath, R S; van Oirschot, B A J A; Zwarts, P H W; Ulrich, D J O; Anil, S; Jansen, J A; van den Beucken, J J J P

    2016-02-01

    This work aimed to compare in vitro degradation of dense PLGA microspheres and milled PLGA particles as porogens within CPC, considering that the manufacturing of milled PLGA is more cost-effective when compared with PLGA microspheres. Additionally, we aimed to examine the effect of porogen amount within CPC/PLGA on degradation and bone formation. Our in vitro results showed no differences between both forms of PLGA particles (as porogens in CPC; spherical for microspheres, irregular for milled) regarding morphology, porosity, and degradation. Using milled PLGA as porogens within CPC/PLGA, we evaluated the effect of porogen amount on degradation and bone forming capacity in vivo. Titanium landmarks surrounded by CPC/PLGA with 30 and 50 wt % PLGA, were implanted in forty femoral bone defects of twenty male Wistar rats. Histomorphometrical results showed a significant temporal decrease in the amount of CPC, for both formulas, and confirmed that 50 wt % PLGA degrades faster than 30 wt%, and allows for a 1.5-fold higher amount of newly formed bone. Taken together, this study demonstrated that (i) milled PLGA particles perform equal to PLGA microspheres, and (ii) tuning of the PLGA content in CPC/PLGA is a feasible approach to leverage material degradation and bone formation.

  10. 3D printing of octacalcium phosphate bone substitutes

    Directory of Open Access Journals (Sweden)

    Vladimir S. Komlev

    2015-06-01

    Full Text Available Biocompatible calcium phosphate ceramic grafts are able of supporting new bone formation in appropriate environment. The major limitation of these materials usage for medical implants is the absence of accessible methods for their patient-specific fabrication. 3D printing methodology is an excellent approach to overcome the limitation supporting effective and fast fabrication of individual complex bone substitutes. Here we proposed a relatively simple route for 3D printing of octacalcium phosphates in complexly shaped structures by the combination of inkjet printing with post-treatment methodology. The printed octacalcium phosphate blocks were further implanted in the developed cranial bone defect followed by histological evaluation. The obtained result confirmed the potential of the developed octacalcium phosphates bone substitutes, which allowed 2.5-time reducing of defect’s diameter at 6.5 months in a region where native bone repair is extremely inefficient.

  11. Calcium, vitamin D, and your bones

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000490.htm Calcium, vitamin D, and your bones To use the sharing ... and maintain strong bones. How Much Calcium and Vitamin D Do I Need? Amounts of calcium are ...

  12. The stability mechanisms of an injectable calcium phosphate ceramic suspension.

    Science.gov (United States)

    Fatimi, Ahmed; Tassin, Jean-François; Axelos, Monique A V; Weiss, Pierre

    2010-06-01

    Calcium phosphate ceramics are widely used as bone substitutes in dentistry and orthopedic applications. For minimally invasive surgery an injectable calcium phosphate ceramic suspension (ICPCS) was developed. It consists in a biopolymer (hydroxypropylmethylcellulose: HPMC) as matrix and bioactive calcium phosphate ceramics (biphasic calcium phosphate: BCP) as fillers. The stability of the suspension is essential to this generation of "ready to use" injectable biomaterial. But, during storage, the particles settle down. The engineering sciences have long been interested in models describing the settling (or sedimentation) of particles in viscous fluids. Our work is dedicated to the comprehension of the effect of the formulation on the stability of calcium phosphate suspension before and after steam sterilization. The rheological characterization revealed the macromolecular behavior of the suspending medium. The investigations of settling kinetics showed the influence of the BCP particle size and the HPMC concentration on the settling velocity and sediment compactness before and after sterilization. To decrease the sedimentation process, the granule size has to be smaller and the polymer concentration has to increase. A much lower sedimentation velocity, as compared to Stokes law, is observed and interpreted in terms of interactions between the polymer network in solution and the particles. This experimentation highlights the granules spacer property of hydrophilic macromolecules that is a key issue for interconnection control, one of the better ways to improve osteoconduction and bioactivity. PMID:20229185

  13. Preparation and Properties of Biphasic Calcium Phosphate Scaffolds Multiply Coated with HA/PLLA Nanocomposites for Bone Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Lei Nie

    2012-01-01

    Full Text Available A well-developed BCP scaffolds coated with multilayer of HA/PLLA nanocomposites with interconnectivity, high porosity, and moderate compressive strength as well as good biocompatibility were fabricated for bone tissue engineering. After being multiply coated with HA/PLLA nanocomposites, the scaffolds maintained the BCP framework structure, and the porous network structure of scaffolds remained unchanged; however, the compressive strength was increased with the increase of coating layer number of HA/PLLA nanocomposites. The prepared scaffolds showed lower variation of pH values in SBF solution, and an increase of coating layer number led to the decrease of the biodegradation rate at different days. Moreover, the multilayer coating scaffolds had good cytocompatibility, showing no negative effects on cells growth and proliferation. Furthermore, the bone-like apatite layer was built obviously in the interface of scaffold after 21 days after implantation in SD rat muscle. In conclusion, the BCP scaffold coated with multilayer of HA/PLLA nanocomposites could be a candidate as an excellent substitute for damaged or defect bone in bone tissue engineering.

  14. Bone reaction adjacent to microplasma-sprayed calcium phosphate-coated oral implants subjected to an occlusal load, an experimental study in the dog

    NARCIS (Netherlands)

    Junker, R.; Manders, P.J.D.; Wolke, J.G.C.; Borisov, Y.; Braceras, I.; Jansen, J.A.

    2011-01-01

    BACKGROUND: A new microplasma spraying equipment (MSE) to deposit calcium phosphate (CaP) ceramic coatings onto titanium substrates has been developed. With this system, it is possible to spray fine particles and to apply textured hydroxylapatite coatings onto titanium surfaces. Moreover, due to the

  15. Biomimetic calcium phosphate coatings on recombinant spider silk fibres

    Energy Technology Data Exchange (ETDEWEB)

    Yang Liang; Habibovic, Pamela; Van Blitterswijk, Clemens A [Department of Tissue Regeneration, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Hedhammar, My; Johansson, Jan [Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, the Biomedical Centre, Box 575, 751 23 Uppsala (Sweden); Blom, Tobias; Leifer, Klaus [Department of Engineering Sciences, Uppsala University, Box 534, S-751 21 Uppsala (Sweden)

    2010-08-01

    Calcium phosphate ceramic coatings, applied on surfaces of metallic and polymeric biomaterials, can improve their performance in bone repair and regeneration. Spider silk is biocompatible, strong and elastic, and hence an attractive biomaterial for applications in connective tissue repair. Recently, artificial spider silk, with mechanical and structural characteristics similar to those of native spider silk, has been produced from recombinant minispidroins. In the present study, supersaturated simulated body fluid was used to deposit calcium phosphate coatings on recombinant spider silk fibres. The mineralization process was followed in time using scanning electron microscopy equipped with an energy dispersive x-ray (EDX) detector and Raman spectroscope. Focused ion beam technology was used to produce a cross section of a coated fibre, which was further analysed by EDX. Preliminary in vitro experiments using a culture of bone marrow-derived human mesenchymal stem cells (hMSCs) on coated fibres were also performed. This study showed that recombinant spider silk fibres were successfully coated with a homogeneous and thick crystalline calcium phosphate layer. In the course of the mineralization process from modified simulated body fluid, sodium chloride crystals were first deposited on the silk surface, followed by the deposition of a calcium phosphate layer. The coated silk fibres supported the attachment and growth of hMSCs.

  16. Synthesis and characterization of zirconium-doped calcium phosphate biomaterial

    International Nuclear Information System (INIS)

    A new synthesis route for the production of calcium phosphate biomaterial was developed by using organic di-(2-ethylhexyl) phosphoric acid (DEHPA) mixed with calcium hydroxide slurry. Unlike the conventional involving chemical precipitation process this new method involves a sol-gel process. Another advantage of this method is the starting material DEHPA can form strong bonding with many elements including zirconium and rare earths. This makes it suitable to be used as drug delivery material especially those involving bone related disease. It also improves the biomaterial strength with the presence of zirconium oxide phase. From XRD analysis, the result shows the present of HA, α-TCP and β-TCP. The addition of different rare elements on to the calcium phosphate will varies the amount of these three phases. SEM analysis was also performed to study the morphology of the calcium phosphate material. The presence of the rare earths on to the calcium phosphate was established by using the EDS technique. (Author)

  17. Combined Effect of a Microporous Layer and Type I Collagen Coating on a Biphasic Calcium Phosphate Scaffold for Bone Tissue Engineering

    OpenAIRE

    Mun-Hwan Lee; Changkook You; Kyo-Han Kim

    2015-01-01

    In this study, type I collagen was coated onto unmodified and modified microporous biphasic calcium phosphate (BCP) scaffolds. Surface characterization using a scanning electron microscope (SEM) and a surface goniometer confirmed the modification of the BCP coating. The quantity of the collagen coating was investigated using Sirius Red staining, and quantitative assessment of the collagen coating showed no significant differences between the two groups. MG63 cells were used to evaluate cell p...

  18. Characterization and biocompatibility of fluoridated biphasic calcium phosphate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Z.L. [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Yu, H.Y. [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China)], E-mail: yhyang6812@tfol.com; Zeng, Q. [Institute for Nanobiomedical Technology and Membrane Biology, Sichuan University, Chengdu 610041 (China); He, H.W. [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China)

    2008-11-15

    Biphasic calcium phosphate ceramics (BCP) has been widely used in tooth and bone implants due to its excellent biocompatibility. Incorporation of fluorine ions in BCP has drawn much attention because of the beneficial role played by the fluorine ions in bone and tooth growth. The aim of this study was to obtain fluoridated biphasic calcium phosphate (FBCP) by immersing BCP into saturated ZnF{sub 2} solution with F{sup -} concentration of 3500 mg/l at different times. The phase and incorporation of fluoride into BCP were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). The biomineralization and influence of FBCP on osteoblastic behavior were evaluated and compared with that of biphasic calcium phosphate (BCP). The results exhibited that the phase evolution of the BCP was affected by the fluoride incorporation and the FBCP significantly improved the differentiation and proliferation of osteoblasts. These findings suggest that the FBCP would be very useful as a bone reconstructive material.

  19. In vivo performance of microstructured calcium phosphate formulated in novel water-free carriers

    NARCIS (Netherlands)

    Davison, N.L.; Yuan, H.; Bruijn, de J.D.; Barrere-de Groot, F.YF.

    2012-01-01

    Osteoinductive calcium phosphate (CaP) ceramics can be combined with polymeric carriers to make shapeable bone substitutes as an alternative to autologous bone; however, carriers containing water may degrade the ceramic surface microstructure, which is crucial to bone formation. In this study five n

  20. Three-dimensionally Perforated Calcium Phosphate Ceramics

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Porous calcium phosphate ceramics were produced by compression molding using a special mold followed by sintering. The porous calcium phosphate ceramics have three-dimensional and penetrated open pores380-400μm in diameter spaced at intervals of 200μm. The layers of the linear penetration pores alternately lay perpendicular to pore direction. The porosity was 59%-65% . The Ca/P molar ratios of the porous calcium phosphate ceramics range from 1.5 to 1.85. A binder containing methyl cellulose was most effective for preparing the powder compact among vinyl acetate, polyvinyl alcohol, starch, stearic acid, methyl cellulose and their mixtures. Stainless steel, polystyrene, nylon and bamboo were used as the long columnar male dies for the penetrated open pores. When polystyrene, nylon and bamboo were used as the long columnar male dies, the dies were burned out during the sintering process. Using stainless steel as the male dies with the removal of the dies before heat treatment resulted in a higher level of densification of the calcium phosphate ceramic.

  1. Protein Adsorption of Calcium Phosphate Ceramics in vitro

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In order to provide valuable information for the design of new calcium phosphate bone repair materials, bone tissue engineering scaffold materials, and other clinical application, the interaction between calcium phosphate materials and proteins were investigated. The adsorption of the calcium phosphate ceramic to the protein was investigated by using FT- IR, XPS, SEM, and SDS- PAGE. As the results shown, the proteins were strongly adsorbed by the CPC, and a shift of the feature peak of the protein and also a chemical shift in the Ca2p and O1s bind energy of CPC was observed. This indicated that the acidic amino-group and alkaline amino- residue on the proteins' surface bonded to the Ca2 + in the β- TCP crystal by ionic bond and the proteins' alkaline amino groups to the oxygen in PO3-4 by hydrogen bond and electrostatic attraction. The adsorption mechanism of the protein in the CPC can be described as three ndsorption layers: irreversible chemical adsorption layer, physical adsorption layer and biomineralized adsorption layer.

  2. 21 CFR 182.6215 - Monobasic calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Monobasic calcium phosphate. 182.6215 Section 182.6215 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6215 Monobasic calcium phosphate. (a) Product. Monobasic calcium phosphate. (b) Conditions of use....

  3. 21 CFR 582.6215 - Monobasic calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Monobasic calcium phosphate. 582.6215 Section 582.6215 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6215 Monobasic calcium phosphate. (a) Product. Monobasic calcium phosphate. (b) Conditions of use....

  4. 3D Printing of Octacalcium Phosphate Bone Substitutes.

    Science.gov (United States)

    Komlev, Vladimir S; Popov, Vladimir K; Mironov, Anton V; Fedotov, Alexander Yu; Teterina, Anastasia Yu; Smirnov, Igor V; Bozo, Ilya Y; Rybko, Vera A; Deev, Roman V

    2015-01-01

    Biocompatible calcium phosphate ceramic grafts are able of supporting new bone formation in appropriate environment. The major limitation of these materials usage for medical implants is the absence of accessible methods for their patient-specific fabrication. 3D printing methodology is an excellent approach to overcome the limitation supporting effective and fast fabrication of individual complex bone substitutes. Here, we proposed a relatively simple route for 3D printing of octacalcium phosphates (OCP) in complexly shaped structures by the combination of inkjet printing with post-treatment methodology. The printed OCP blocks were further implanted in the developed cranial bone defect followed by histological evaluation. The obtained result confirmed the potential of the developed OCP bone substitutes, which allowed 2.5-time reducing of defect's diameter at 6.5 months in a region where native bone repair is extremely inefficient.

  5. Investigation of mechanism of bone regeneration in a porous biodegradable calcium phosphate (CaP) scaffold by a combination of a multi-scale agent-based model and experimental optimization/validation

    Science.gov (United States)

    Zhang, Le; Qiao, Minna; Gao, Hongjie; Hu, Bin; Tan, Hua; Zhou, Xiaobo; Li, Chang Ming

    2016-08-01

    Herein, we have developed a novel approach to investigate the mechanism of bone regeneration in a porous biodegradable calcium phosphate (CaP) scaffold by a combination of a multi-scale agent-based model, experimental optimization of key parameters and experimental data validation of the predictive power of the model. The advantages of this study are that the impact of mechanical stimulation on bone regeneration in a porous biodegradable CaP scaffold is considered, experimental design is used to investigate the optimal combination of growth factors loaded on the porous biodegradable CaP scaffold to promote bone regeneration and the training, testing and analysis of the model are carried out by using experimental data, a data-mining algorithm and related sensitivity analysis. The results reveal that mechanical stimulation has a great impact on bone regeneration in a porous biodegradable CaP scaffold and the optimal combination of growth factors that are encapsulated in nanospheres and loaded into porous biodegradable CaP scaffolds layer-by-layer can effectively promote bone regeneration. Furthermore, the model is robust and able to predict the development of bone regeneration under specified conditions.

  6. Selective laser sintering of calcium phosphate materials for orthopedic implants

    Science.gov (United States)

    Lee, Goonhee

    Two technologies, Solid Freeform Fabrication (SFF) and bioceramics are combined in this work to prepare bone replacement implants with complex geometry. SFF has emerged as a crucial technique for rapid prototyping in the last decade. Selective Laser Sintering (SLS) is one of the established SFF manufacturing processes that can build three-dimensional objects directly from computer models without part-specific tooling or human intervention. Meanwhile, there have been great efforts to develop implantable materials that can assist in regeneration of bone defects and injuries. However, little attention has been focused in shaping bones from these materials. The main thrust of this research was to develop a process that can combine those two separate efforts. The specific objective of this research is to develop a process that can construct bone replacement material of complex geometry from synthetic calcium phosphate materials by using the SLS process. The achievement of this goal can have a significant impact on the quality of health care in the sense that complete custom-fit bone and tooth structures suitable for implantation can be prepared within 24--48 hours of receipt of geometric information obtained either from patient Computed Tomographic (CT) data, from Computer Aided Design (CAD) software or from other imaging systems such as Magnetic Resonance Imaging (MRI) and Holographic Laser Range Imaging (HLRI). In this research, two different processes have been developed. First is the SLS fabrication of porous bone implants. In this effort, systematic procedures have been established and calcium phosphate implants were successfully fabricated from various sources of geometric information. These efforts include material selection and preparation, SLS process parameter optimization, and development of post-processing techniques within the 48-hour time frame. Post-processing allows accurate control of geometry and of the chemistry of calcium phosphate, as well as

  7. Physicochemical characterization of zinc-substituted calcium phosphates

    Indian Academy of Sciences (India)

    DOROTA WALCZYK; DAGMARA MALINA; MILENA KRÓL; KLAUDIA PLUTA; AGNIESZKA SOBCZAK-KUPIEC

    2016-04-01

    Biocompatible and bioactive calcium phosphates can make chemical bonds with living bones. Improvement of their biological and physicochemical properties can be achieved by doping with various ions that are presented in natural apatites of bones. These substitutions influence lattice parameters, structure and morphology of apatites. In recent times great attention has been devoted to zinc ions that are the second most abundant trace element present in bones. Zinc embedded into calcium phosphate may enhance the bone formation and in addition exhibits antifungal and antibacterial properties. Therefore, it is rational to form structures incorporated with this ion. In this paper the incorporation of the Zn ions into natural and synthetic calcium phosphates has been reported.Natural hydroxyapatites (HAs) applied in this study were derived mainly from pork bones whereas both brushite and synthetic were formed using wet chemical methods. Ambient temperature synthesis leads to the formation ofbrushite, whereas the process performed at elevated temperature gives HA. Subsequently, attained structures were modified with Zn ions by using in situ or sorption procedures. Phase composition and morphology of obtained materials were determined by means of X-ray diffractometry, Fourier transform infrared spectroscopy and scanning electron microscopy equipped with energy-dispersive spectroscopy. Introduced XRD patterns depict changes of the crystallinity of HA with the increase in the amount of embedded zinc ions. On the contrary, no changes of the crystallinity were observed for the brushite doped with Zn ions. Morphology of attained powders, visualized using scanningelectron microscopy exemplified structural changes between calcium phosphates conjugated with zinc ions. Many authors report that the addition of small amounts of Zn ions leads to loss of crystallinity and decrease of lattice parameters. Interestingly, upon addition of Zn ions to the natural and synthetic HAp by sorption

  8. Use of a strontium-enriched calcium phosphate cement in accelerating the healing of soft-tissue tendon graft within the bone tunnel in a rabbit model of anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Kuang, G M; Yau, W P; Lu, W W; Chiu, K Y

    2013-07-01

    We investigated whether strontium-enriched calcium phosphate cement (Sr-CPC)-treated soft-tissue tendon graft results in accelerated healing within the bone tunnel in reconstruction of the anterior cruciate ligament (ACL). A total of 30 single-bundle ACL reconstructions using tendo Achillis allograft were performed in 15 rabbits. The graft on the tested limb was treated with Sr-CPC, whereas that on the contralateral limb was untreated and served as a control. At timepoints three, six, nine, 12 and 24 weeks after surgery, three animals were killed for histological examination. At six weeks, the graft-bone interface in the control group was filled in with fibrovascular tissue. However, the gap in the Sr-CPC group had already been completely filled in with new bone, and there was evidence of the early formation of Sharpey fibres. At 24 weeks, remodelling into a normal ACL-bone-like insertion was found in the Sr-CPC group. Coating of Sr-CPC on soft tissue tendon allograft leads to accelerated graft healing within the bone tunnel in a rabbit model of ACL reconstruction using Achilles tendon allograft.

  9. Study on rapid-setting calcium phosphate bone cement%快速固化型磷酸钙骨水泥的研究

    Institute of Scientific and Technical Information of China (English)

    杨洪; 王凯; 师明旭; 刘晓娜; 邓亚美

    2011-01-01

    The physical and chemical properties of tetracalcium phosphate ( TTCP)-Monocalcium phosphate monohydrate ( MCPM ) -β-Tricalaium phosphate (β-TCP) based bone cement are studied using simulated body fluid (SBF) as a chemical liquid. The results show that the compressive strength increases at first and then decreases with the increasing of liquid-solid ratio. When the liquid-solid ratio is 0. 445,it can reach the maximum strength(15. 23 Mpa). The setting reaction of CPC is rapid. When the liquid-solid ratio is 0. 594,the final time is 12 minites. The compressive strength gradually decreases with the increasing of soaking time. The obtained bone cements are characterized by XRD and SEM. The results find the occurrence of hydroxyapatite(HA) in all obtained crystals of setting reaction. However, there is no new crystal phase generated after soaking.%用模拟体液(simulated body fluid,SBF)作为固化液,对磷酸四钙(TTCP)+一水磷酸二氢钙(MCPM)+β-磷酸三钙(β -TCP)系骨水泥理化性质进行研究.结果表明,随液固比增大,抗压强度先增加后降低,当液固比为0.445时,抗压强度达到最大值15.23 MPa;骨水泥固化较快,液固比为0.594时,t_f为12 min;随着浸泡时间的增加抗压强度逐渐减小;X射线(XRD)和扫描电镜(SEM)分析结果显示,随液固比改变,固化反应结晶物均有羟基磷灰石(HA)相出现;浸泡后的骨水泥没有新物相产生.

  10. Mechanism of calcium phosphates precipitation in liquid crystals; Mecanisme de precipitation de phosphates de calcium dans des cristaux liquides

    Energy Technology Data Exchange (ETDEWEB)

    Prelot, B.; Zemb, T

    2004-04-01

    The possibility of using as a precursor an easily wet meso-porous powder would be a breakthrough in the preparation of nuclear waste storage ceramics. A concentrated solution containing ions to be stored would wet a dry powder and then, subjected to mild compression, lead to a micro-crystalline matrix of calcium phosphate at acceptable temperatures. Since no porous calcium phosphate different from calcined bone (patented) is described as porous precursor, we have compared the different synthesis routes towards meso-porous ceramics. First, we considered homogeneous precipitation of slats in water: using initially off-stoichiometry in reaction, micron-sized hydroxyapatite particles are produced with a specific surface up to 100 m{sup 2}/g. Then, we consider the classical route of precipitation of an hybrid material in the miscibility gap of a phase diagram, when an hexagonal liquid crystal is used a matrix for precipitation. The surfactant family consists in single chain surfactants containing phosphates as head-group to poison the growing surface of calcium phosphate nano-domains. Since the reaction is still too brutal, we considered using a cat-anionic precursor material of controllable surface charge. For certain concentrations and molar ratios, a new structure not yet described in surfactant precipitation literature is observed: since the periodicity is lower than twice the chain length, a disordered constant curvature monolayer (instead of the classical cylinder of twice chain length diameter) of surfactant is implied. Finally, we have investigated synthesis routes implying slow dissolution of pre-formed calcium phosphate in an already existing hexagonal matrix. For all these routes of synthesis, micro-structural determinations using SAXS, WARS and BET are performed, with a special attention to comparison of the precipitation material, the matrix obtained with all elements present, and also the material obtained after calcinations. (authors)

  11. Long-term survival of calcium phosphate-coated dental implants: a meta-analytical approach to the clinical literature

    NARCIS (Netherlands)

    Oirschot, B.A. van; Bronkhorst, E.M.; Beucken, J.J.J.P van den; Meijer, G.J.; Jansen, J.B.M.J.; Junker, R.

    2013-01-01

    BACKGROUND: Calcium phosphate ceramic coatings have the potential to compensate for challenging bone conditions such as delayed or impaired bone healing and low bone quantity or density. Thus, the increasing universal prevalence of subjects with such challenging bone conditions might be paralleled b

  12. Single Step Sintered Calcium Phosphate Fibers from Avian EGG Shell

    Science.gov (United States)

    Dadhich, Prabhash; Das, Bodhisatwa; Dhara, Santanu

    2013-11-01

    Different forms of calcium-phosphate (Hydoxyapatite, α-TCP, β-TCP, CDHA) minerals are found to be major component of bone tissue. Development of calcium-phosphate (CaP) based fibrous microstructures is of significant research interest worldwide owing to its improved mechanical properties and higher interconnectivity. Here we represent a method for single step sintered wet-spun Fibers of calcium phosphate from avian egg shells for biomedical applications. Raw egg shell powder was mixed with chitosan solution and Phosphoric acid. The mixture is milled in a ball mill overnight and then filtered. The slurry was de-aired using 100 microliter 1-octanol per 100 ml of slurry as antifoaming and wet spun in coagulation bath. Fiber was dried overnight and sintered at different temperatures for microstructure and phase analysis. Both green and sintered Fibers were physico-chemical characterized by SEM, EDX, XRD, TGA, DSC, FTIR, and stereo-zoom microscopy. The fibers obtained in this procedure are found to have highly porous interconnected structures which can provide good cell adhesion and therefore can be used for bioactive scaffold making.

  13. Structure, properties and animal study of a calcium phosphate/calcium sulfate composite cement.

    Science.gov (United States)

    Chen, Wei-Luen; Chen, Chang-Keng; Lee, Jing-Wei; Lee, Yu-Ling; Ju, Chien-Ping; Lin, Jiin-Huey Chern

    2014-04-01

    In-vitro and in-vivo studies have been conducted on an in-house-developed tetracalcium phosphate (TTCP)/dicalcium phosphate anhydrous (DCPA)/calcium sulfate hemihydrate (CSH)-derived composite cement. Unlike most commercial calcium-based cement pastes, the investigated cement paste can be directly injected into water and harden without dispersion. The viability value of cells incubated with a conditioned medium of cement extraction is >90% that of Al2O3 control and >80% that of blank medium. Histological examination reveals excellent bonding between host bone and cement without interposition of fibrous tissues. At 12 weeks-post implantation, significant remodeling activities are found and a new bone network is developed within the femoral defect. The 26-week samples show that the newly formed bone becomes more mature, while the interface between residual cement and the new bone appears less identifiable. Image analysis indicates that the resorption rate of the present cement is much higher than that of TTCP or TTCP/DCPA-derived cement under similar implantation conditions.

  14. Bioactivity of calcium phosphate bioceramic coating fabricated by laser cladding

    Science.gov (United States)

    Zhu, Yizhi; Liu, Qibin; Xu, Peng; Li, Long; Jiang, Haibing; Bai, Yang

    2016-05-01

    There were always strong expectations for suitable biomaterials used for bone regeneration. In this study, to improve the biocompatiblity of titanium alloy, calcium phosphate bioceramic coating was obtained by laser cladding technology. The microstructure, phases, bioactivity, cell differentiation, morphology and resorption lacunae were investigated by optical microscope (OM), x-ray diffraction (XRD), methyl thiazolyl tetrazolium (MTT) assay, tartrate-resistant acid phosphatase (TRAP) staining and scanning electronic microscope (SEM), respectively. The results show that bioceramic coating consists of three layers, which are a substrate, an alloyed layer and a ceramic layer. Bioactive phases of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) were found in ceramic coating. Osteoclast precursors have excellent proliferation on the bioceramic surface. The bioceramics coating could be digested by osteoclasts, which led to the resorption lacunae formed on its surface. It revealed that the gradient bioceramic coating has an excellent bioactivity.

  15. Discrimination between biologically relevant calcium phosphate phases by surface-analytical techniques

    International Nuclear Information System (INIS)

    The spatially resolved phase identification of biologically relevant calcium phosphate phases (CPPs) in bone tissue is essential for the elucidation of bone remodeling mechanisms and for the diagnosis of bone diseases. Analytical methods with high spatial resolution for the discrimination between chemically quite close phases are rare. Therefore the applicability of state-of-the-art ToF-SIMS, XPS and EDX as chemically specific techniques was investigated. The eight CPPs hydroxyapatite (HAP), β-tricalcium phosphate (β-TCP), α-tricalcium phosphate (α-TCP), octacalcium phosphate (OCP), dicalcium phosphate dihydrate (DCPD), dicalcium phosphate (DCP), monocalcium phosphate (MCP) and amorphous calcium phosphate (ACP) were either commercial materials in high purity or synthesized by ourselves. The phase purity was proven by XRD analysis. All of the eight CPPs show different mass spectra and the phases can be discriminated by applying the principal component analysis method to the mass spectrometric data. The Ca/P ratios of all phosphates were determined by XPS and EDX. With both methods some CPPs can be distinguished, but the obtained Ca/P ratios deviate systematically from their theoretical values. It is necessary in any case to determine a calibration curve, respectively the ZAF values, from appropriate standards. In XPS also the O(1s)-satellite signals are correlated to the CPPs composition. Angle resolved and long-term XPS measurements of HAP clearly prove that there is no phosphate excess at the surface. Decomposition due to X-ray irradiation has not been observed.

  16. Discrimination between biologically relevant calcium phosphate phases by surface-analytical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kleine-Boymann, Matthias, E-mail: matthias.kleine-boymann@phys.chemie.uni-giessen.de; Rohnke, Marcus, E-mail: marcus.rohnke@phys.chemie.uni-giessen.de; Henss, Anja, E-mail: anja.henss@phys.chemie.uni-giessen.de; Peppler, Klaus, E-mail: klaus.peppler@phys.chemie.uni-giessen.de; Sann, Joachim, E-mail: joachim.sann@phys.chemie.uni-giessen.de; Janek, Juergen, E-mail: juergen.janek@phys.chemie.uni-giessen.de

    2014-08-01

    The spatially resolved phase identification of biologically relevant calcium phosphate phases (CPPs) in bone tissue is essential for the elucidation of bone remodeling mechanisms and for the diagnosis of bone diseases. Analytical methods with high spatial resolution for the discrimination between chemically quite close phases are rare. Therefore the applicability of state-of-the-art ToF-SIMS, XPS and EDX as chemically specific techniques was investigated. The eight CPPs hydroxyapatite (HAP), β-tricalcium phosphate (β-TCP), α-tricalcium phosphate (α-TCP), octacalcium phosphate (OCP), dicalcium phosphate dihydrate (DCPD), dicalcium phosphate (DCP), monocalcium phosphate (MCP) and amorphous calcium phosphate (ACP) were either commercial materials in high purity or synthesized by ourselves. The phase purity was proven by XRD analysis. All of the eight CPPs show different mass spectra and the phases can be discriminated by applying the principal component analysis method to the mass spectrometric data. The Ca/P ratios of all phosphates were determined by XPS and EDX. With both methods some CPPs can be distinguished, but the obtained Ca/P ratios deviate systematically from their theoretical values. It is necessary in any case to determine a calibration curve, respectively the ZAF values, from appropriate standards. In XPS also the O(1s)-satellite signals are correlated to the CPPs composition. Angle resolved and long-term XPS measurements of HAP clearly prove that there is no phosphate excess at the surface. Decomposition due to X-ray irradiation has not been observed.

  17. Towards understanding biomineralization:calcium phosphate in a biomimetic minerallzation process

    Institute of Scientific and Technical Information of China (English)

    Yu-rong CAI; Rui-kang TANG

    2009-01-01

    Biomineralization processes result in organic/inorganic hybrid materials with complex shapes,hiemrchi-cal structures.and superior matefial properties. Recent developments in biominemlization and biomatarials have demonstrated that calcium phosphate particles play an important role in the formation of hard tissues in nature. In this paper,current concepts in biominemlization,such as nano assembly,biomimetic shell structure,and their applications are introduced. It is confirmed experimentally that enamel-or bone-liked apatita can be achieved by oriented aggregations using nano calcium phosphates as starting matarials. The assembly of calcium phosphate can be either promoted or inhibited by diflerent biomolecules so that the kinetics can he regulated biologically.In this paper,the role of nano calcium phosphate in tissue repair is highligllted Furthermore,a new,interesting result on biomimetie mineralization 1s Introduced,which can offer an artificial shell for living cells via a biomimatic method .

  18. Characterization of a calcium phosphate cement based on alpha-tricalcium phosphate obtained by wet precipitation process

    International Nuclear Information System (INIS)

    There are several systems of calcium phosphate cements being studied. Those based on alpha-tricalcium phosphate are of particular interest. After setting they produce calcium deficient hydroxyapatite similar to bone like hydroxyapatite. This work aims to obtain alpha-tricalcium phosphate powders by the wet precipitation process, using calcium nitrate and phosphoric acid as reagents. This powder was characterized by infrared spectroscopy, X-ray diffraction and particle size distribution. In order to prepare the calcium phosphate cement, the powder was mixed with an accelerator in an aqueous solution. The mechanical properties of the cement were assessed and it was evaluated by means of apparent density, X-ray diffraction and scanning electron microscopy. The described method produced crystalline alpha-tricalcium phosphate as the major phase. The calcium phosphate cement showed high values of compression strength (50 MPa). The soaking of the cement in a simulated body fluid (SBF) formed a layer of hydroxyapatite like crystals in the surface of the samples. (author)

  19. Effects of calcium phosphate bioceramics on skeletal muscle cells.

    Science.gov (United States)

    Sun, J S; Tsuang, Y H; Yao, C H; Liu, H C; Lin, F H; Hang, Y S

    1997-02-01

    With advances in ceramics technology, calcium phosphate bioceramics have been applied as bone substitutes. The effects of implants on bony tissue have been investigated. The effects upon adjacent skeletal muscles have not been determined. The focus of this work is to elucidate the biological effects of various calcium phosphate bioceramics on skeletal muscles. Four different kinds of powder of calcium phosphate biomaterials including beta-tricalcium phosphate (beta-TCP), hydroxyapatite (HA), beta-dicalcium pyrophosphate (beta-DCP) and sintered beta-dicalcium pyrophosphate (SDCP), were tested by myoblast cell cultures. The results were analyzed by cell count, cell morphology and concentration of transforming growth factor beta 1 (TGF-beta 1) in culture medium. The cell population and TGF-beta 1 concentration of the control sample increased persistently as the time of culture increased. The changes in cell population and TGF-beta 1 concentration in culture medium of the beta-TCP and HA were quite low in the first 3 days of culture, then increased gradually toward the seventh day. The changes in cell population and TGF-beta 1 concentration in culture medium of the silica, beta-DCP, and SDCP were quite similar. They were lower during the first day of culture but increased and reached that of the control medium after 7 days' culture. Most cells on B-TCP and HA diminished in size with radially spread, long pseudopods. We conclude that HA and beta-TCP are thought to have an inhibitory effect on growth of the myoblasts. The HA and beta-TCP may interfere with the repair and regeneration of injured skeletal muscle after orthopedic surgery.

  20. Seed selections for crystallization of calcium phosphate for phosphorus recovery

    Institute of Scientific and Technical Information of China (English)

    SONG Yong-hui; Dietfried DONNERT; Ute BERG; Peter G. WEIDLER; Rolf NUEESCH

    2007-01-01

    Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus (P). In order to select suitable seed for P recovery from wastewater, three seeds including Apatite (AP), Juraperle (JP) and phosphate-modified Juraperle (M-JP) were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.

  1. Calcium phosphate mineralization is widely applied in crustacean mandibles

    OpenAIRE

    Shmuel Bentov; Aflalo, Eliahu D.; Jenny Tynyakov; Lilah Glazer; Amir Sagi

    2016-01-01

    Crustaceans, like most mineralized invertebrates, adopted calcium carbonate mineralization for bulk skeleton reinforcement. Here, we show that a major part of the crustacean class Malacostraca (which includes lobsters, crayfishes, prawns and shrimps) shifted toward the formation of calcium phosphate as the main mineral at specified locations of the mandibular teeth. In these structures, calcium phosphate is not merely co-precipitated with the bulk calcium carbonate but rather creates speciali...

  2. Novel phosphate glasses for bone regeneration applications

    OpenAIRE

    Burling, Luke Donald

    2006-01-01

    Phosphate glass with additions of sodium, magnesium and/or calcium were investigated for their potential to be used as the reinforcing phase in a completely degradable long fibre composite. Glasses were prepared from phosphate salts as opposed to oxides and melted under air in platinum/gold crucibles. The effect of cation addition on the material properties and biocompatibility was investigated. Glasses were characterised using a number of complimentary techniques, including: XRD, XPS, DSC...

  3. The salutary effect of dietary calcium on bone mass in a rat model of simulated weightlessness

    Science.gov (United States)

    Bikle, D. D.; Globus, R.; Halloran, B. P.; Morey-Holton, E.

    1985-01-01

    Whether supplementation of dietary calcium reduces the differences in bone mass of unweighed limbs and normally weighted limbs, and whether parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,25(OH)2D) respond differently to dietary calcium in unweighted animals in comparison with pair-fed controls was studied. The hind limbs of rats were unweighted by a tail suspension method and diets containing 0.1% to 2.4% calcium. After 2 weeks serum calcium, phosphorus, PTH and 1,25(OH)2D intestinal calcium transport were determined and bone mass, ash weight, and calcium in the tibia, L-1 vertebra, and humerus were measured. No significant differences in body weights were observed among the various groups. Suspended rats maintained constant levels of serum calcium and phosphate over the wide range of dietary calcium. Serum PTH and 1,25(OH)2D and intestinal calcium transport fell as dietary calcium was increased. Bone calcium in the tibia and vertebra from suspended rats remained less than that from pair-fed control. It is suggested that although no striking difference between suspended and control animals was observed in response to dieteary calcium, increasing dietary calcium may reduce the negative impact of unloading on the calcium content of the unweighted bones. The salutary effect of high dietary calcium appears to be due to inhibition of bone resorption rather than to stimulation of bone formation.

  4. Pathogenic Mineralization of Calcium Phosphate on Human Heart Valves

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    When calcium phosphate forms in soft tissues such as blood vessels and heart valves, it causes disease. The abnormal formation of calcium phosphate is called pathogenic mineralization or pathogenic calcification. Cases of rheumatic heart disease (RHD) always occur with fibrotic and calcified tissue of heart valve. In this article, samples taken from calcified human heart valves were studied. The characterization was performed by scanning electronic micrascope, X-ray Diffraction and transmission electron microscopy with selective diffraction patterns. It is found for the first time that calcium phosphate grains existing in the calcified human heart valves contain octacalcium phosphate (OCP).

  5. Preparation and Characterization of Porous Calcium Phosphate Bioceramics

    Institute of Scientific and Technical Information of China (English)

    Honglian Dai; Xinyu Wang; Yinchao Han; Xin Jiang; Shipu Li

    2011-01-01

    β-tricalcium phosphate (β-TCP) powder and Na2O-CaO-MgO-P2O5 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering at 850℃. The as-prepared ceramics possess a high porosity with partial three-dimension interconnected macro- and micro-pores. As in vitro experiment testified, the calcium phosphate ceramics (CPCs) has good degradability.

  6. Reinforcement Strategies for Load-Bearing Calcium Phosphate Biocements

    Directory of Open Access Journals (Sweden)

    Martha Geffers

    2015-05-01

    Full Text Available Calcium phosphate biocements based on calcium phosphate chemistry are well-established biomaterials for the repair of non-load bearing bone defects due to the brittle nature and low flexural strength of such cements. This article features reinforcement strategies of biocements based on various intrinsic or extrinsic material modifications to improve their strength and toughness. Altering particle size distribution in conjunction with using liquefiers reduces the amount of cement liquid necessary for cement paste preparation. This in turn decreases cement porosity and increases the mechanical performance, but does not change the brittle nature of the cements. The use of fibers may lead to a reinforcement of the matrix with a toughness increase of up to two orders of magnitude, but restricts at the same time cement injection for minimal invasive application techniques. A novel promising approach is the concept of dual-setting cements, in which a second hydrogel phase is simultaneously formed during setting, leading to more ductile cement–hydrogel composites with largely unaffected application properties.

  7. Biocompatibility and degradation of poly(DL-lactic-co-glycolic acid)/calcium phosphate cement composites

    NARCIS (Netherlands)

    Ruhe, P.Q.; Hedberg, E.L.; Padron, N.T.; Spauwen, P.H.M.; Jansen, J.A.; Mikos, A.G.

    2005-01-01

    Injectable calcium phosphate (Ca-P) cement materials exhibit favorable osteocompatible behavior but are resorbed slowly because of a lack of a bone ingrowth-enabling macroporosity. In this study, poly(DL-lactic-co-glycolic acid) (PLGA) microparticles (average size 66 +/- 25 microm) were incorporated

  8. Immobilization of calcium and phosphate ions improves the osteoconductivity of titanium implants.

    Science.gov (United States)

    Sunarso; Toita, Riki; Tsuru, Kanji; Ishikawa, Kunio

    2016-11-01

    In this work, to elevate weak osteoconductivity of titanium (Ti) implant, we prepared a Ti implant having both calcium and phosphate ions on its surface. To modify calcium and phosphate ions onto Ti, phosphate ions were first immobilized by treating the Ti with a NaH2PO4 solution, followed by CaCl2 treatment to immobilize calcium ions, which created the calcium and phosphate ions-modified Ti (Ca-P-Ti). X-ray photoelectron spectroscopy and thin-layer X-ray diffraction measurement confirmed that both phosphate and calcium ions were co-immobilized onto the Ti surface on the molecular level. Three-hour after seeding MC3T3-E1 murine pre-osteoblast cells on substrates, cell number on Ca-P-Ti was much larger than that of Ti and phosphate-modified Ti (P-Ti), but was similar to that of calcium-modified Ti (Ca-Ti). Also, MC3T3-E1 cells on Ca-P-Ti expressed larger amount of vinculin, a focal adhesion protein, than those on other substrates, probably resulting in larger cell size as well as greater cell proliferation on Ca-P-Ti than those on other substrates. Alkaline phosphatase activity of cells on Ca-P-Ti was greater than those on Ti and P-Ti, but was almost comparable to that of Ca-Ti. Moreover, the largest amount of bone-like nodule formation was observed on Ca-P-Ti. These results provide evidence that calcium and phosphate ions-co-immobilization onto Ti increased the osteoconductivity of Ti by stimulating the responses of pre-osteoblast cells. This simple modification would be promising technique for bone tissue implant including dental and orthopedic implants. PMID:27524023

  9. Characterization of calcium phosphate coating and zinc incorporation on the porous alumina scaffolds

    Directory of Open Access Journals (Sweden)

    Hermes de Souza Costa

    2007-03-01

    Full Text Available Bone ingrowth requires materials with the existence of open and interconnected pores with diameters larger than 150 µm for proper circulation of nutrients. Such materials must possess enough mechanical strength to avoid failure whilst offering a bioactive surface for bone regeneration. We have developed porous ceramic alumina scaffold with compressive strength that achieves 3.3 MPa by replication method by using the network structure of cellular polymer foam. However, the biocompatibility of ceramics based on Al2O3 requires further improvement so that it could have strong bonding to natural bone tissue. To address this problem of the interface between alumina and bone, we have developed a novel calcium phosphate with Zn2+ (CaP-Zn coating onto porous alumina ceramic scaffold by impregnating with calcium phosphate/poly(vinyl alcohol slurry. The tri-dimensional alumina scaffold coated with CaP-Zn was extensively characterized by SEM, EDS and FTIR.

  10. Coating of calcium phosphate on biometallic materials by electrophoretic deposition

    Institute of Scientific and Technical Information of China (English)

    ZHANG Er-lin; YANG Ke

    2005-01-01

    Although biometallic materials have been used as bone implant materials for a long time, they are still detected as foreign bodies by human immune system. Calcium phosphate coating, especially hydroxyapatite(HA)coating attracts special attention due to its good biocompatibility. Being one of the effective methods used to deposit HA coating onto the metallic implant, the electrophoretic deposition(EPD) was reviewed in detail, including the process of EPD, the advantages and disadvantages, the important processing factors and the microstructure and mechanical properties of the coating. Research results on the processing and the coating show potential application of EPD process to the biomedical materials surface modification. In addition, the nanoparticulate HA coating as a new trend in HA coating was also introduced.

  11. Mapping calcium phosphate activated gene networks as a strategy for targeted osteoinduction of human progenitors.

    Science.gov (United States)

    Eyckmans, Jeroen; Roberts, Scott J; Bolander, Johanna; Schrooten, Jan; Chen, Christopher S; Luyten, Frank P

    2013-06-01

    Although calcium phosphate-containing biomaterials are promising scaffolds for bone regenerative strategies, the osteoinductive capacity of such materials is poorly understood. In this study, we investigated whether endogenous mechanisms of in vivo calcium phosphate-driven, ectopic bone formation could be identified and used to induce enhanced differentiation in vitro of the same progenitor population. To accomplish this, human periosteum derived cells (hPDCs) were seeded on hydroxyapatite/collagen scaffolds (calcium phosphate rich matrix or CPRM), or on decalcified scaffolds (calcium phosphate depleted matrix or CPDM), followed by subcutaneous implantation in nude mice to trigger ectopic bone formation. In this system, osteoblast differentiation occurred in CPRM scaffolds, but not in CPDM scaffolds. Gene expression was assessed by human full-genome microarray at 20 h after seeding, and 2, 8 and 18 days after implantation. In both matrices, implantation of the cell constructs triggered a similar gene expression cascade, however, gene expression dynamics progressed faster in CPRM scaffolds than in CPDM scaffolds. The difference in gene expression dynamics was associated with differential activation of hub genes and molecular signaling pathways related to calcium signaling (CREB), inflammation (TNFα, NFkB, and IL6) and bone development (TGFβ, β-catenin, BMP, EGF, and ERK signaling). Starting from this set of pathways, a growth factor cocktail was developed that robustly enhanced osteogenesis in vitro and in vivo. Taken together, our data demonstrate that through the identification and subsequent stimulation of genes, proteins and signaling pathways associated with calcium phosphate mediated osteoinduction, a focused approach to develop targeted differentiation protocols in adult progenitor cells can be achieved.

  12. Bone Up on the Need for Calcium.

    Science.gov (United States)

    Mann, Peggy

    1987-01-01

    Most grade-schoolers drink milk at each meal, but teens, especially girls, often switch to carbonated soda at mealtime just as they should be building up their bone bank of calcium. Why calcium is important and how to get enough of it are covered. (MT)

  13. Calcium phosphate bone cement containing ABK and PLLA. Sustained release of ABK, the BMD of the femur in rats, and histological examination

    Energy Technology Data Exchange (ETDEWEB)

    Kusaka, T.; Tanaka, A.; Sasaki, S.; Takano, I.; Tahara, Y.; Ishii, Y. [Kyorin Univ., Tokyo (Japan). Dept. of Orhtopaedic Surgery

    2001-07-01

    Bone cement was prepared by mixing CPC95 (Mitsubishi Material Co., Ltd.), ABK, and PLLA at a ratio of 14 : 1 : 2. In vitro, Antibiotic sustained release tests were performed by the total amount exchange method. In animal experiments, the bone cement was infused into the right femur of 18-month-old female SD rats. After 1, 2, 4, or 6 months, the BMD was determined by DXA in the bilateral femoral bones. In addition, hard tissue specimens were prepared, and the state of bone formation was observed. The release of the antibiotic was 1.73 {mu}g/ml until 18 days after administration, maintaining a concentration over the MIC80 for MRSA. In the animal experiments, the BMD significantly increased after 2 - 4 months. In the hard tissue specimens, direct binding on the bone-cement interface and bone formation in the cement were observed after 1 month. (orig.)

  14. Monolithic calcium phosphate/poly(lactic acid) composite versus calcium phosphate-coated poly(lactic acid) for support of osteogenic differentiation of human mesenchymal stromal cells

    OpenAIRE

    Tahmasebi Birgani, Zeinab; van Blitterswijk, Clemens A.; Habibovic, Pamela

    2016-01-01

    Calcium phosphates (CaPs), extensively used synthetic bone graft substitutes, are often combined with other materials with the aim to overcome issues related to poor mechanical properties of most CaP ceramics. Thin ceramic coatings on metallic implants and polymer-ceramic composites are examples of such hybrid materials. Both the properties of the CaP used and the method of incorporation into a hybrid structure are determinant for the bioactivity of the final construct. In the present study, ...

  15. Chitosan-coated electrospun PLA fibers for rapid mineralization of calcium phosphate.

    Science.gov (United States)

    Lin, Chi-Chang; Fu, Shu-Juan; Lin, Yu-Ching; Yang, I-Kuan; Gu, Yesong

    2014-07-01

    In this work, hydroxyapatite (HA) mineralized on chitosan (CS)-coated poly(lactic acid) (PLA) nanofiber mat was prepared and compared in terms of mineralization characteristics. Significant calcium phosphate crystals formed on various concentrations of CS-coated PLA fiber mat with better uniformity after 2h of incubation in 10 times simulated body fluid (10× SBF). X-ray diffraction results further indicated that the composition of the deposited mineral was a mixture of dicalcium phosphate dehydrates and apatite. Chitosan, a cationic polysaccharide, can promote more nucleation and growth of calcium phosphate under conditions of 0.4% chitosan concentrations. These results indicated that HA-mineralized on CS-coated PLA fiber mat can be prepared directly via simply using CS coating followed by SBF immersion, and the results also suggest that this composite can mimic structural, compositional, and biological functions of native bone and can serve as a good candidate for bone tissue engineering (BTE). PMID:24768970

  16. ATR-FTIR measurements of albumin and fibrinogen adsorption: Inert versus calcium phosphate ceramics.

    Science.gov (United States)

    Boix, Marcel; Eslava, Salvador; Costa Machado, Gil; Gosselin, Emmanuel; Ni, Na; Saiz, Eduardo; De Coninck, Joël

    2015-11-01

    Arthritis, bone fracture, bone tumors and other musculoskeletal diseases affect millions of people across the world. Nowadays, inert and bioactive ceramics are used as bone substitutes or for bone regeneration. Their bioactivity is very much dictated by the way proteins adsorb on their surface. In this work, we compared the adsorption of albumin and fibrinogen on inert and calcium phosphates ceramics (CaPs) using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to follow in situ protein adsorption on these materials. To this effect, we developed a sol-gel technique to control the surface chemistry of an ATR-FTIR detector. Hydroxyapatite adsorbed more albumin and β-tricalcium phosphate adsorbed more fibrinogen. Biphasic calcium phosphate presented the lowest adsorption among CaP for both proteins, illustrating the effect of surface heterogeneities. Inert ceramics adsorbed a lower amount of both proteins compared with bioactive ceramics. A significant change was observed in the conformation of the adsorbed protein versus the surface chemistry. Hydroxyapatite produced a larger loss of α-helix structure on albumin and biphasic calcium phosphate reduced β-sheet percentage on fibrinogen. Inert ceramics produced large α-helix loss on albumin and presented weak interaction with fibrinogen. Zirconia did not adsorb albumin and titanium dioxide promoted huge denaturalization of fibrinogen.

  17. Calcium phosphate nanocoatings and nanocomposites, part 2: thin films for slow drug delivery and osteomyelitis.

    Science.gov (United States)

    Ben-Nissan, Besim; Macha, Innocent; Cazalbou, Sophie; Choi, Andy H

    2016-01-01

    During the last two decades although many calcium phosphate based nanomaterials have been proposed for both drug delivery, and bone regeneration, their coating applications have been somehow slow due to the problems related to their complicated synthesis methods. In order to control the efficiency of local drug delivery of a biomaterial the critical pore sizes as well as good control of the chemical composition is pertinent. A variety of calcium phosphate based nanocoated composite drug delivery systems are currently being investigated. This review aims to give an update into the advancements of calcium phosphate nanocoatings and thin film nanolaminates. In particular recent research on PLA/hydroxyapatite composite thin films and coatings into the slow drug delivery for the possible treatment of osteomyelitis is covered. PMID:26891748

  18. 活性CPC/BMSCs用于牙槽嵴保存的实验研究%Active Porous Calcium Phosphate Cement with Bone Marrow Stromal Cells in Alveolar Ridge Preservation

    Institute of Scientific and Technical Information of China (English)

    谭鸾君; 王磊; 黄远亮

    2011-01-01

    目的:研究体外培养的毕格犬骨髓基质细胞(bone marrow stromal cells,BMSCs)与活性多孔磷酸钙(calcium phosphate cement,CPC)复合物应用于牙槽嵴保存的可行性.方法:将体外培养的毕格犬第2代BMSCs接种于活性CPC上,形成活性CPC/BMSCs复合物.拔除4只毕格犬双侧下颌骨的第二、三、四前磨牙,随机选取一侧植入活性CPC/BMSCs,另一侧分别为空白对照、自体骨、活性CPC.分别于术后第4周和第10周取材,硬组织切片和CT扫描分析牙槽嵴的高度变化.结果:第10周时,活性CPC/BMSCs组牙槽嵴高度的减少值较对侧的CPC组、自体骨组、空白对照组牙槽嵴高度的减少值低(P<0.05),差别有统计学意义.硬组织切片显示第10周时活性CPC/BMSCs组具有良好的新骨形成.结论:活性CPC/BMSCs有利于牙槽嵴保存.%Objective: To examine the efficancy of active porous calcium phosphate cement together with bone marrow stromal cells (BMSCs) in alveolar ridge preservation. Methods: The 2nd,3rd,4th premolars in both sides of mandible of 4 beagle dogs were extracted and 24 extraction wounds were created. Randomly, one side of the mandible wounds were implanted by BMSCs with the growth factor/porous CPC composite. The opposite side of wounds were implanted by CPC,autologus bone, or keep void respectively. After four and ten weeks, the beagles were sacrificed. The gross specimens were examined, CT sean images, and mineralized specimen preparations were prepared. Results: CT analysis showed that alveolar ridge in each group experienced some degree of alveolar absorption. After ten weeks, the alveolar ridge height reduction values in active-CPC group was smaller than the CPC group, autogenous bone group, and blank group respectively (P<0.05). The difference has statistical significance. Tissue slides also revealed an effective osteogensis in those wounds implanted with active-Cpc. Conclusions: The BMSCs/active CPC complex is favorable for

  19. Penggunaan batuan fosfat NDCP (natural defluorinated calcium phosphate sebagai pengganti dicalcium phosphate dalam ransom ayam broiler

    Directory of Open Access Journals (Sweden)

    Arnold P. Sinurat

    1995-08-01

    Full Text Available An experiment was conducted to study the utilization of local rock phosphate or natural defluorinated calcium phosphate (NDCP as phosphorus source for broilers by using the imported dicalcium phosphate (DCP as a reference. The study was designed by formulating 6 experimental diets which consist of 2 phosphorus sources (DCP dan NDCP and 3 dietary total P levels (0 .55 ; 0.65 and 0 .75%. Each diet was fed to 60 chickens (10 replicates with 6 birds each from three day old to 6 weeks of age. Parameters observed were feed consumption, body weight gain, mortality, Ca and P retention, and ash content of tibia bones. Results showed that dietary phosphorus levels (0.55 to 0.75% did not significantly affect body weight gain, feed consumption, and mortalities. However, better feed conversion ratio was obtained when dietary phosphorus level was 0.55%. The NDCP treated birds could significantly gain heavier weight compared with those received DCP, although this improvement was also followed by an increase in the feed consumption. The relative biological value of phosphorus in NDCP was 101 `7n. It is concluded that NDCP can he used in broilers diet to replace DCP as phosphorus source.

  20. Ossification Vesicles with Calcium Phosphate in the Eyes of the Insect Copium teucrii (Hemiptera: Tingidae

    Directory of Open Access Journals (Sweden)

    Javier Garcia-Guinea

    2011-01-01

    Full Text Available Arthropod eyes are built of repeating units named ommatidia. Each single ommatidium unit contains a cluster of photoreceptor cells surrounded by support cells and pigment cells. The insect Copium eye ommatidia include additional calcium-phosphate deposits, not described in insects to date, which can be examined today using a combined set of modern microscopy and spectroscopy techniques. Teucrium gnaphalodes L'Her plants, growing in central Spain, develop galls induced by Copium insects. A survey of C. teucrii adult specimens resulted in surprising environmental scanning electron microscopy (ESEM images, showing that their bright red eyes contain a calcium-phosphate mineralization. A complete survey of Copium eye specimens was performed by ESEM using energy-dispersive spectroscopy, backscattered electron detector and cathodoluminescence (CL probes, field emission scanning electron microscopy, micro-Raman spectroscopy, and confocal laser scanning microscopy in order to learn ommatidia features, such as chemical composition, molecular structure, cell membrane, and internal ommatidium eye fluids and calcium-phosphate distribution deposits. The CL panchromatic images distinguish between the calcium-phosphate ommatidium and calcium-phosphate setae, which are more apatite rich. They show Raman bands attributable to bone tissue apatite biomaterials, such as bone, collagen, lipids, and blood, i.e., peptides, amide-S, amide-II, amide-III, and cytochrome P-450scc. The chemical composition of both galls and leaves of T. gnaphalodes was determined by gas chromatography – mass spectrometry (GC-MS of their extracts. The spectrometric and microscopic images reveal that the calcium-phosphate mineralization is formed and constrained to Copium ommatidia, which are both matrix vesicles generating mixtures of apatite collagen and operational compound eyes of the insect.

  1. The Antimicrobial Action of Silver Halides in Calcium Phosphate

    OpenAIRE

    Kalniņa, D; Gross, K; Onufrijevs, P.; Daukšta, E; Nikolajeva, V; Stankeviciute, Z; Kareiva, A.

    2015-01-01

    Silver halides represent a yet unexplored avenue for imparting antimicrobial activity to calcium phosphates. Negtively charged silver halide colloids (AgI, AgBr and AgCl) were added to synthesized amorphous calcium phosphate. Concurrent melting of silver halides and crystallization to carbonated apatite at 700 oC increased the silver halide surface area available to bacteria and formed a lower solubility apatite. The effect of the matrix solubility on antimicrobial response could ...

  2. The utilization of rock phosphate (natural defluorinated calcium phosphate or NDCP in laying hens diet to replace dicalcium phosphate

    Directory of Open Access Journals (Sweden)

    A.P Sinurat

    1996-06-01

    Full Text Available An experimentwas conducted to study the utilization of local rock phosphate or natural defluorinated calcium phosphate (NDCP as phosphorus source for layer chickens by using the imported dicalcium phosphate (DCP as a reference. Eight experimental diets consisted of 2 source of phosphorus (DCP and NDCP and 4 dietary total P levels (0.4, 0.5, 0.6 and 0.7% were formulated. Each diet was fed to 24 pullets (6 replicates with 4 birds each from 20 weeks of age to 14 weeks of egg production. Observations were made on feed consumption, egg production, egg weight, mortality, egg quality, Ca and P retention and ash content of tibial bones . Results showed no significant effect of different source and level of phosphorus tested on egg production (% HD, feed consumption, egg weight and mortality rates . Egg shell thickness was depressed in NDCP diet as compared with DCP, however this only occurred at firstmonth of production. It is concluded that the NDCP can be used in layers diet to replace DCP as phosphorus source. The relative biological value of phosphorus inNDCP is 96% for layers.

  3. Effects of 1,25-dihydroxicolecalciferol and dietary calcium-phosphate on distribution of lead to tissues during growth

    International Nuclear Information System (INIS)

    The susceptibility to the toxic effects of lead (Pb) is mainly mediated by age and nutritional and hormonal status, and children are among the most vulnerable to them. During growth, an increase in calcium, phosphate and vitamin D in diet is recommended to enhance calcium and phosphate intestinal absorption and bone deposit. Calcium and phosphate reduce lead intestinal absorption, and 1,25-dihydroxicolecalciferol (1,25(OH)2D3) (active metabolite of vitamin D) increases both lead and calcium intestinal absorption. However, the effects of 1,25(OH)2D3 on lead bone deposit and redistribution to soft tissues are not well known. In this study, we examined the effects of calcium-phosphate diet supplementation and the administration of 1,25(OH)2D3 on Pb distribution to soft tissue and bone in growing rats exposed to Pb. Rats (21 days old) were exposed for 28 days to 100 ppm of Pb solution in drinking water. Calcium and phosphate in diet were increased from 1 to 2.5% and from 0.65 to 1.8%, respectively, and 1,25(OH)2D3 was administrated by intraperitoneal injection of 7.2 ng/kg every 7 days. Between 21 and 49 days, the body weight increased about 5 times. The results showed that high calcium-phosphate diet led to lower Pb concentration in blood and in bone, but Pb liver and kidney concentrations increased, which indicates that absorption and bone deposit redistribution of Pb decreased. On the other hand, no effect of this diet rich in calcium-phosphate in Pb concentration was observed in brain. Blood and bone Pb concentrations increased even more when the high calcium-phosphate diet included 1,25(OH)2D3. In the rats treated only with 1,25(OH)2D3, blood and bone Pb concentrations were lower. Higher concentrations of lead in the soft organs were observed also in rats treated under a high calcium-phosphate diet plus 1,25(OH)2D3 administration. The above mentioned results suggested that 1,25(OH)2D3 induces an increased absorption and redistribution of Pb, and therefore, it may

  4. Calcium and bone disorders in pregnancy

    Directory of Open Access Journals (Sweden)

    Shriraam Mahadevan

    2012-01-01

    Full Text Available Significant transplacental calcium transfer occurs during pregnancy, especially during the last trimester, to meet the demands of the rapidly mineralizing fetal skeleton. Similarly, there is an obligate loss of calcium in the breast milk during lactation. Both these result in considerable stress on the bone mineral homeostasis in the mother. The maternal adaptive mechanisms to conserve calcium are different in pregnancy and lactation. During pregnancy, increased intestinal absorption of calcium from the gut mainly due to higher generation of calcitriol (1,25 dihydroxy vitamin D helps in maintaining maternal calcium levels. On the other hand, during lactation, the main compensatory mechanism is skeletal resorption due to increased generation of parathormone related peptide (PTHrP from the breast. Previous studies suggest that in spite of considerable changes in bone mineral metabolism during pregnancy, parity and lactation are not significantly associated with future risk for osteoporosis. However, in India, the situation may not be the same as a significant proportion of pregnancies occur in the early twenties when peak bone mass is not yet achieved. Further, malnutrition, anemia and vitamin D deficiency are commonly encountered in this age group. This may have an impact on future bone health of the mother. It may also probably provide an opportunity for health care providers for prevention. Other metabolic bone diseases like hypoparathyroidism, hyperparathyroidism and pseudohypoparathyroidism are rarely encountered in pregnancy. Their clinical implications and management are also discussed.

  5. Effect of humic substances on the precipitation of calcium phosphate

    Institute of Scientific and Technical Information of China (English)

    SONG Yong-hui; Hermann H. HAHN; Erhard HOFFMANN; Peter G. WEIDLER

    2006-01-01

    For phosphorus (P) recovery from wastewater, the effect of humic substances (HS) on the precipitation of calcium phosphate was studied. Batch experiments of calcium phosphate precipitation were undertaken with synthetic water that contained 20 mg/L phosphate (as P) and 20 mg/L HS (as dissolved organic carbon, DOC) at a constant pH value in the range of 8.0-10.0. The concentration variations of phosphate, calcium (Ca) and HS were measured in the precipitation process; the crystalline state and compositions of the precipitates were analysed by powder X-ray diffraction (XRD) and chemical methods, respectively. It showed that at solution pH 8.0, the precipitation rate and removal efficiency of phosphate were greatly reduced by HS, but at solution pH ≥9.0,the effect of HS was very small. The Ca consumption for the precipitation of phosphate increased when HS was added; HS was also removed from solution with the precipitation of calcium phosphate. At solution pH 8.0 and HS concentrations ≤ 3.5 mg/L, and at pH ≥ 9.0 and HS concentrations ≤ 10 mg/L, the final precipitates were proved to be hydroxyapatite (HAP) by XRD. The increases of solution pH value and initial Ca/P ratio helped reduce the influence of HS on the precipitation of phosphate.

  6. Study on silicate-calcium phosphate composite bone cement modified by sodium carbonate solution%碳酸钠液相改性硅-磷酸钙复合骨水泥研究

    Institute of Scientific and Technical Information of China (English)

    李青林; 杨帮成

    2014-01-01

    以质量分数70%的硅酸三钙(Ca3 SiO5,C3 S)和30%磷酸氢钙(CaHPO4·2H2 O,DCPD)复合得到的 DCP30粉体材料为固相,以不同浓度碳酸钠溶液为液相,得到碳酸钠改性骨水泥材料。使用 X 射线衍射(XRD)、扫描电镜(SEM)、万能材料试验机等手段对不同浓度改性材料进行表征。结果显示:添加碳酸钠液相,骨水泥初、终凝时间分别缩短至16和55 min;调控碳酸钠液相浓度,可以实现短期抗压强度优化;使用碳酸钠后,固化自发生成羟基磷灰石(HA)。浸泡模拟体液(SBF)7天,材料表面覆盖 HA 沉积层,生物活性优越。碳酸钠液相改性硅-磷酸钙复合骨水泥体系的水化性能、短期力学性能以及生物活性均优于Ca3 SiO5水泥和未改性硅-磷酸钙复合骨水泥,是一种良好的生物活性骨修复材料。%Sodium carbonate solution modified bone cement materials have been prepared using sodium carbonate solution with dif-ferent concentration as liquid phase and DCP30 powder material obtained by 70% mass fraction tricalcium silicate (Ca3 SiO5 ,C3 S) and 30% dicalcium phosphate (CaHPO4 ·2H2 O,DCPD)as the solid phase.The materials were characterized by the means of X-ray diffraction (XRD),scanning electron microscope (SEM)and mechanical test.The results show that the initial and final set-ting time of bone cement is reduced to 16 and 55 min by the addition of sodium carbonate solution.The short-term mechanical strength can be optimized by controlling the concentration of sodium carbonate solution.Hydroxyapatite (HA)can spontaneously form after the use of sodium carbonate solution.HA forms on the surface of bone-cement after immersion in SBF for 7 days,indi-cating its good bioactivity.The modified system shows better hydraulic property,bioactivity and mechanical strength than Ca3 SiO5 cement and unmodifiled silicate-calcium phosphate composite bone cement,suggesting the new system is a

  7. Aqueous deposition of calcium phosphates and silicate substituted calcium phosphates on magnesium alloys

    International Nuclear Information System (INIS)

    Attempts were made to deposit homogeneous films of calcium phosphates (CaPs) on two magnesium alloy systems, AZ31 and Mg–4Y, through an aqueous phosphating bath method. The deposition of silicate substituted CaPs by this aqueous method was also explored as silicate substitution is believed to increase the bioactivity of CaPs. The effect of doped and undoped coatings on the in vitro degradation and bioactivity of both alloy systems was studied. FTIR and EDX confirmed the deposition of Ca, P, and Si on both alloys and the coatings appeared to consist primarily biphasic mixtures of hydroxyapatite and β-TCP. These largely inhomogeneous coatings, as observed by SEM, were not shown to have any significant effect on maintaining the physiological pH of the culture medium in comparison to the uncoated samples, as the pH remained approximately in the 8.4–8.7 range. Interestingly, despite similar pH profiles between the coated and uncoated samples, CaP coatings affected the degradation of both alloys. These doped and undoped calcium phosphate coatings were observed to decrease the degradation of AZ31 whereas they increased the degradation of Mg–4Y. In vitro studies on cell attachment using MC3T3-E1 mouse osteoblasts showed that between the uncoated alloys, Mg–4Y appeared to be the more biocompatible of the two. Silicate substituted CaP coatings were observed to increase the cell attachment on AZ31 compared to bare and undoped CaPs coated samples, but did not have as great of an effect on increasing cell attachment on Mg–4Y.

  8. The role of prenucleation clusters in surface-induced calcium phosphate crystallization

    Science.gov (United States)

    Dey, Archan; Bomans, Paul H. H.; Müller, Frank A.; Will, Julia; Frederik, Peter M.; de With, Gijsbertus; Sommerdijk, Nico A. J. M.

    2010-12-01

    Unravelling the processes of calcium phosphate formation is important in our understanding of both bone and tooth formation, and also of pathological mineralization, for example in cardiovascular disease. Serum is a metastable solution from which calcium phosphate precipitates in the presence of calcifiable templates such as collagen, elastin and cell debris. A pathological deficiency of inhibitors leads to the uncontrolled deposition of calcium phosphate. In bone and teeth the formation of apatite crystals is preceded by an amorphous calcium phosphate (ACP) precursor phase. ACP formation is thought to proceed through prenucleation clusters-stable clusters that are present in solution already before nucleation-as was recently demonstrated for CaCO3 (refs 15,16). However, the role of such nanometre-sized clusters as building blocks for ACP has been debated for many years. Here we demonstrate that the surface-induced formation of apatite from simulated body fluid starts with the aggregation of prenucleation clusters leading to the nucleation of ACP before the development of oriented apatite crystals.

  9. Calcium phosphate coating on magnesium alloy by biomimetic method :Investigation of morphology ,composition and formation process

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Magnesium alloy has similar mechanical properties with natural bone and can degrade via corrosion in the electrolytic environment of the human body.Calcium phosphate has been proven to possess bioactivity and bone inductivity.In order to integrate both advantages,calcium phosphate coating was fabricated on magnesium alloy by a biomimetic method.Supersaturated calcification solutions (SCSs) with different Ca/P ratio and C1- concentration were used as mimetic solutions.The morphology,composition and formation process of the coating were studied with scanning electron microscopy (SEM),energy dispersive spectrometer (EDS),Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD).The results show that a uniform calcium phosphate coating was observed on magnesium alloy,the properties of which could be adjusted by the SCSs with different Ca/P ratio.The formation process of the coating was explored by immersing magnesium alloy in SCSs with different Cl- concentration which could adjust the hydrogen production.According to SEM results,the hydrogen bubbles were associated with the formation of grass-like and flower-like coating morphologies.In conclusion,the biomimetic method was effective to form calcium phosphate coating on magnesium alloy and the morphology and composition of the coating could be accommodated by the Ca/P ratio and Cl- concentration in SCSs.

  10. Calcium phosphate coating on titanium using laser and plasma spray

    Science.gov (United States)

    Roy, Mangal

    Though calcium phosphate (CaP) coated implants are commercially available, its acceptance is still not wide spread due to challenges related to weaker interfacial bonding between metal and ceramic, and low crystallinity of hydroxyapatite (HA). The objectives of this research are to improve interfacial strength, crystallinity, phase purity and bioactivity of CaP coated metallic implants for orthopaedic applications. The rationale is that forming a diffuse and gradient metal-ceramic interface will improve the interfacial strength. Moreover, reducing CaP particles exposure to high temperature during coating preparation, can lead to improvement in both crystallinity and phase purity of CaP. In this study, laser engineered net shaping (LENS(TM)) was used to coat Ti metal with CaP. LENS(TM) processing enabled generation of Ti+TCP (tricalcium phosphate) composite coating with diffused interface, that also increased the coating hardness to 1049+/-112 Hv compared to a substrate hardness of 200+/-15 Hv. In vitro bone cell-material interaction studies confirmed the bioactivity of TCP coatings. Antimicrobial properties of the TCP coatings were improved by silver (Ag) electrodeposition. Along with LENS(TM), radio frequency induction plasma spray, equipped with supersonic plasma nozzle, was used to prepare HA coatings on Ti with improved crystallinity and phase purity. The coating was made of multigrain HA particles of ˜200 nm in size, which consisted of 15--20 nm HA grains. In vitro bone cell-material interaction and in vivo rat model studies confirmed the HA coatings to be bioactive. Furthermore, incorporation of Sr2+ improved bone cell of HA coatings interaction. A combination of LENS(TM) and plasma spray was used to fabricate a compositionally graded HA coatings on Ti where the microstructure varied from pure HA at the surface to pure Ti substrate with a diffused Ti+TCP composite region in between. The plasma spray system was used to synthesize spherical HA nano powder from

  11. Biomimetic Nanocomposites of Calcium Phosphate and Self-Assembling Triblock and Pentablock Copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Drew Lenzen Enlow

    2006-08-09

    In an effort to mimic the growth of natural bone, self-assembling, micelle and gel-forming copolymers were used as a template for calcium phosphate precipitation. Because of the cationic characteristics imparted by PDEAEM end group additions to commercially available Pluronic{reg_sign} Fl27, a direct ionic attraction mechanism was utilized and a polymer-brushite nanocomposite spheres were produced. Brushite coated spherical micelles with diameters of {approx}40 nm, and agglomerates of these particles (on the order of 0.5 {mu}m) were obtained. Thickness and durability of the calcium phosphate coating, and the extent of agglomeration were studied. The coating has been shown to be robust enough to retain its integrity even below polymer critical micelle concentration and/or temperature. Calcium phosphate-polymer gel nanocomposites were also prepared. Gel samples appeared as a single phase network of agglomerated spherical micelles, and had a final calcium phosphate concentration of up to 15 wt%. Analysis with x-ray diffraction and NMR indicated a disordered brushite phase with the phosphate groups linking inorganic phase to the polymer.

  12. Biomimetic Nanocomposites of Calcium Phosphate and Self-Assembling Triblock and Pentablock Copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Enlow, Drew Lenzen [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    In an effort to mimic the growth of natural bone, self-assembling, micelle and gel-forming copolymers were used as a template for calcium phosphate precipitation. Because of the cationic characteristics imparted by PDEAEM end group additions to commercially available Pluronic{reg_sign} Fl27, a direct ionic attraction mechanism was utilized and a polymer-brushite nanocomposite spheres were produced. Brushite coated spherical micelles with diameters of ~40 nm, and agglomerates of these particles (on the order of 0.5 μm) were obtained. Thickness and durability of the calcium phosphate coating, and the extent of agglomeration were studied. The coating has been shown to be robust enough to retain its integrity even below polymer critical micelle concentration and/or temperature. Calcium phosphate-polymer gel nanocomposites were also prepared. Gel samples appeared as a single phase network of agglomerated spherical micelles, and had a final calcium phosphate concentration of up to 15 wt%. Analysis with x-ray diffraction and NMR indicated a disordered brushite phase with the phosphate groups linking inorganic phase to the polymer.

  13. Bone disease in calcium stone forming patients.

    Science.gov (United States)

    Heilberg, I P; Martini, L A; Szejnfeld, V L; Carvalho, A B; Draibe, S A; Ajzen, H; Ramos, O L; Schor, N

    1994-09-01

    The association between idiopathic hypercalciuria and osteopenia (OP) has been recently recognized. It is not established whether or not calcium intake plays a critical role in the loss of bone mass. Fifty-five calcium stone forming patients with either absorptive hypercalciuria (AH) or fasting hypercalciuria (FH), 29 males and 26 premenopausal females, were submitted to dual photon absorptiometry at lumbar spine. Calcium intake was assessed by a 72 hr dietary record. OP was detected in 20% (11/55) of patients, being more common among men, 9/26 (35%) than in women, 2/29 (7%), p < 0.05. Male FH patients presented lower mean bone mineral density (BMD) than sex, weight and age-matched control (1.058 +/- 0.18 vs 1.209 +/- 0.13 g/cm2, X +/- SD, p < 0.05). OP was more frequent in FH patients, 7/20 (35%) than in AH patients 4/35 (11%), albeit the difference was not statistically significant. There was no correlation between calcium intake and BMD measurement. Six osteopenic male FH patients were further submitted to histomorphometric evaluation with tetracycline double labeling. Bone volume was lower than the controls (13.2 +/- 3.0 vs 27.2 +/- 3.7%, p < 0.05). Osteoid surfaces were reduced, although not significantly (10.1 +/- 8.2% vs 15.9 +/- 6.7%). Eroded surfaces were markedly increased (23.9 +/- 13.4 vs 4.2 +/- 1.4%, p < 0.05). The bone formation rate was very low with a complete lack of tetracycline double labeling in 4 patients. These data suggest low bone volume, tendency to low bone formation, increased bone resorption and a severe mineralization defect, consistent with normal or low bone turnover osteoporosis. PMID:7994936

  14. Calcium phosphate nanocoatings and nanocomposites, part I: recent developments and advancements in tissue engineering and bioimaging.

    Science.gov (United States)

    Choi, Andy H; Ben-Nissan, Besim

    2015-07-01

    A number of materials have been applied as implant coatings and as tissue regeneration materials. Calcium phosphate holds a special consideration, due to its chemical similarity to human bone and, most importantly, its dissolution characteristics, which allow for bone growth and regeneration. The applications of molecular and nanoscale-based biological materials have been and will continue to play an ever increasing role in enhancing and improving the osseointegration of dental and orthopedic implants. More recently, extensive research efforts have been focused on the development and applications of fluorescent nanoparticles and nanocoatings for in vivo imaging and diagnostics as well as devising methods of adding luminescent or fluorescent capabilities to enhance the in vivo functionality of calcium phosphate-based biomedical materials. PMID:26119630

  15. Calcium phosphate cements: study of the beta-tricalcium phosphate--monocalcium phosphate system.

    Science.gov (United States)

    Mirtchi, A A; Lemaitre, J; Terao, N

    1989-09-01

    The possibility of making cements based on beta-tricalcium phosphate (beta-TCP), a promising bone graft material, was investigated. Upon admixture with water, beta-TCP/monocalcium phosphate monohydrate (MCPM) mixtures were found to set and harden like conventional hydraulic cements. Beta-TCP powders with larger particle size, obtained by sintering at higher temperatures, increased the ultimate strength of the cement. Results show that setting occurs after dissolution of MCPM, as a result of the precipitation of dicalcium phosphate dihydrate (DCPD) in the paste. The ultimate tensile strength of the hardened cement is proportional to the amount of DCPD formed. Upon ageing above 40 degrees C, DCPD transforms progressively into anhydrous dicalcium phosphate (DCP), thereby decreasing the strength. Ageing of the pastes in 100% r.h. results in a decay of the mechanical properties. This can be ascribed to an intergranular dissolution of the beta-TCP aggregates as a result of the pH lowering brought about by the MCPM to DCPD conversion.

  16. A construction of novel iron-foam-based calcium phosphate/chitosan coating biodegradable scaffold material.

    Science.gov (United States)

    Wen, Zhaohui; Zhang, Liming; Chen, Chao; Liu, Yibo; Wu, Changjun; Dai, Changsong

    2013-04-01

    Slow corrosion rate and poor bioactivity restrict iron-based implants in biomedical application. In this study, we design a new iron-foam-based calcium phosphate/chitosan coating biodegradable composites offering a priority mechanical and bioactive property for bone tissue engineering through electrophoretic deposition (EPD) followed by a conversion process into a phosphate buffer solution (PBS). Tensile test results showed that the mechanical property of iron foam could be regulated through altering the construction of polyurethane foam. The priority coatings were deposited from 40% nano hydroxyapatite (nHA)/ethanol suspension mixed with 60% nHA/chitosan-acetic acid aqueous solution. In vitro immersion test showed that oxidation-iron foam as the matrix decreased the amount of iron implanted and had not influence on the bioactivity of this implant, obviously. So, this method could also be a promising method for the preparation of a new calcium phosphate/chitosan coating on foam construction. PMID:23827538

  17. A construction of novel iron-foam-based calcium phosphate/chitosan coating biodegradable scaffold material.

    Science.gov (United States)

    Wen, Zhaohui; Zhang, Liming; Chen, Chao; Liu, Yibo; Wu, Changjun; Dai, Changsong

    2013-04-01

    Slow corrosion rate and poor bioactivity restrict iron-based implants in biomedical application. In this study, we design a new iron-foam-based calcium phosphate/chitosan coating biodegradable composites offering a priority mechanical and bioactive property for bone tissue engineering through electrophoretic deposition (EPD) followed by a conversion process into a phosphate buffer solution (PBS). Tensile test results showed that the mechanical property of iron foam could be regulated through altering the construction of polyurethane foam. The priority coatings were deposited from 40% nano hydroxyapatite (nHA)/ethanol suspension mixed with 60% nHA/chitosan-acetic acid aqueous solution. In vitro immersion test showed that oxidation-iron foam as the matrix decreased the amount of iron implanted and had not influence on the bioactivity of this implant, obviously. So, this method could also be a promising method for the preparation of a new calcium phosphate/chitosan coating on foam construction.

  18. Calcium phosphate bioceramics prepared from wet chemically precipitated powders

    Directory of Open Access Journals (Sweden)

    Kristine Salma

    2010-03-01

    Full Text Available In this work calcium phosphates were synthesized by modified wet chemical precipitation route. Contrary to the conventional chemical precipitation route calcium hydroxide was homogenized with planetary mill. Milling calcium oxide and water in planetary ball mill as a first step of synthesis provides a highly dispersed calcium hydroxide suspension. The aim of this work was to study the influence of main processing parameters of wet chemical precipitation synthesis product and to control the morphology, phase and functional group composition and, consequently, thermal stability and microstructure of calcium phosphate bioceramics after thermal treatment. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions after thermal processing (hydroxyapatite [HAp], β-tricalcium phosphate [β-TCP] and HAp/β-TCP by modified wet-chemical precipitation route. The β-TCP phase content in sintered bioceramics samples is found to be highly dependent on the changes in technological parameters and it can be controlled with ending pH, synthesis temperature and thermal treatment. Pure, crystalline and highly thermally stable (up to 1300°C HAp bioceramics with homogenous grainy microstructure, grain size up to 200–250 nm and high open porosity can be successfully obtained by powder synthesized at elevated synthesis temperature of 70°C and stabilizing ending pH at 9.

  19. Electrodeposition on nanofibrous polymer scaffolds: Rapid mineralization, tunable calcium phosphate composition and topography

    OpenAIRE

    He, Chuanglong; Xiao, Guiyong; Jin, Xiaobing; Sun, Chenghui; Ma, Peter X.

    2010-01-01

    We developed a straightforward, fast, and versatile technique to fabricate mineralized nanofibrous polymer scaffolds for bone regeneration in this work. Nanofibrous poly(l-lactic acid) scaffolds were fabricated using both electrospinning and phase separation techniques. An electrodeposition process was designed to deposit calcium phosphate on the nanofibrous scaffolds. Such scaffolds contain a high quality mineral coating on the fiber surface with tunable surface topography and chemical compo...

  20. Biodegradable magnetic calcium phosphate nanoformulation for cancer therapy.

    Science.gov (United States)

    Tang, Zhaomin; Zhou, Yangbo; Sun, Huili; Li, Dan; Zhou, Shaobing

    2014-05-01

    We fabricated a magnetic calcium phosphate nanoformulation by the biomineralization of calcium phosphate on the surface of magnetic nanoparticles with abundant amino groups, and thus the inorganic layer of calcium phosphate can improve the biocompatibility and simultaneously the magnetic iron oxide can maintain the magnetic targeting function. Two types of anticancer drug models, doxorubicin hydrochloride and DNA, were entrapped in these nanocarriers, respectively. This delivery system displayed high pH sensitivity in drug-controlled release profile as the dissolution of CaP under acid pH condition. Magnetofection was performed to investigate the intracellular uptake and the anti-proliferative effect of tumor cells in the presence of an external magnet. The transfection of the DNA-loaded magnetic system in A549 and HepG2 tumor cells demonstrated that the magnetic nanoformulation could enhance the transfection efficiency to 30% with an applied external magnetic field. PMID:24462792

  1. 兔股骨节段缺损模型研究磷酸钙骨水泥骨愈合性能%Bone Healing Capacity of Calcium Phosphate Cement Cylinder in a Rabbit Femur Segmental Defect Model

    Institute of Scientific and Technical Information of China (English)

    王大伟; 潘朝晖; 赵玉祥; 栾兆新

    2015-01-01

    Objective:To investigate the bone healing capacity of calcium phosphate cement ( CPC) cylinder in a rabbit femur seg-mental defect model by comparing the influence of muscle or periosteum as wrapping material.Methods: Pre-hardened CPC cylinder was prepared.Three specimens were analyzed by scanning electron microscopy and X-ray diffraction to characterize its microstructure and chemical composition.Sixty adult rabbits were randomly assigned to four groups,then received a defect size of 15 mm osteotomy within the femurs.The 8-hole plate was fixed with three screws in the proximal and distal part of the defect, respectively.In group A, the fem-oral defects were left alone;in group B, the defects with retained periosteum; in group C, the defects were grafted with CPC cylinder wrapped by muscle;and in group D, the defects were grafted with CPC cylinder wrapped by periosteum.Five rabbits from each group were sacrificed at 4, 8 and 12 weeks postoperatively.The samples were evaluated with radiological, biomechanical and histological meth-ods.Results:Irregular particles were seen on the surface of specimens, the pore size was approximately 10 μm.The peak locations for the hydroxyapatite were seen in the X-ray diffraction patterns of the specimens.Group A showed a few radiographic evidence of new bone formation within the boundary of the defect at 4 weeks.Three bone defects bridged at 8 weeks and 4 bone defects bridged at 12 weeks. Group B showed radiographic evidence of new bone formation at 4 weeks.Four bone defects bridged at 8 weeks and 5 bone defects bridged at 12 weeks.Group C showed discernable interface between the CPC cylinder and both femoral cut ends at 4 weeks, which became invisi-ble at 8 weeks.Defects bridged by continuous callus beside the CPC cylinder in 4 rabbits and completely surrounded in 1 rabbit at 12 weeks.Group D showed better quality of new bone formation, the CPC cylinders were surrounded by new bone at 12 weeks.However, all CPCs retained their

  2. Chemical immobilization of Pb, Cu, and Cd by phosphate materials and calcium carbonate in contaminated soils.

    Science.gov (United States)

    Huang, Guoyong; Su, Xiaojuan; Rizwan, Muhammad Shahid; Zhu, Yifei; Hu, Hongqing

    2016-08-01

    Soil contamination with toxic metals has increasingly become a global concern over the past few decades. Phosphate and carbonate compounds are good passivation materials for Pb immobilization, while the effect of phosphate and carbonate on the immobilization of multiple heavy metals (Pb, Cu, and Cd) in contaminated soils was seldom investigated. In this study, bone meal (BM), phosphate rock (PR), oxalic acid-activated phosphate rock (APR), super phosphate (SP), and calcium carbonate (CC) were added to the contaminated soils to evaluate the effect of phosphate materials and calcium carbonate on the immobilization of Pb, Cu, and Cd. The results showed that the pH of the treated soils increased 1.3-2.7, except SP which decreased 0.5 at most. Compared to the control treatment, all phosphates and calcium carbonate added to the polluted soils increased the fraction of residual metals, and the application of APR, PR, BM, and CC significantly reduced exchangeable and carbonate-bound fraction metals. PR and APR were the most effective for the immobilization of Pb, Cu, and Cd in the soils among these materials. Moreover, the concentrations of all metals in the toxicity characteristic leaching procedure (TCLP) leachate decreased with increasing amounts of amendments, and the concentrations of Pb in the TCLP leachate for soils treated with PR and APR were below the nonhazardous regulatory limit of 5 mg L(-1) (US Environmental Protection Agency). Based on our results, phosphate rock and oxalic acid-activated phosphate rock are effective in the immobilization of multiple metals by reducing their mobility in the co-contaminated soils. PMID:27197655

  3. Calcium phosphate cement II induces osteogenesis and repairs tendon-bone interface injury:a biomechanical analysis%自固化磷酸钙人工骨Ⅱ型诱导成骨及修复腱骨界面损伤的生物力学分析

    Institute of Scientific and Technical Information of China (English)

    李小飞; 谢文瑾; 盛路新; 袁西

    2015-01-01

    背景:自固化磷酸钙人工骨Ⅱ型与重组人骨形态发生蛋白均有一定的成骨诱导作用,存在修复腱骨界面损伤的可能。目的:探讨自固化磷酸钙人工骨Ⅱ型的成骨诱导作用及修复腱骨界面损伤生物力学情况。方法:35只成年健康的新西兰白兔,随机选取5只,处死后取双侧肩关节腱骨界面标本作为正常对照。剩余30只构建腱骨界面损伤模型后,随机等分为实验组和模型组,模型组不填塞任何药物,实验组填塞自固化磷酸钙人工骨Ⅱ型进行修复。结果与结论:填塞自固化磷酸钙人工骨Ⅱ型后,兔损伤腱骨界面明显恢复,且随时间的延长,修复效果更佳,骨形态发生蛋白2表达水平也随之增加,损伤腱骨界面最大抗拉强度以及最大刚度明显增加。表明利用自固化磷酸钙人工骨Ⅱ型复合重组人骨形态发生蛋白对腱骨界面损伤进行修复具有良好的成骨诱导作用,可以促进损伤的修复。%BACKGROUND:Both calcium phosphate cement II and recombinant human bone morphogenetic protein have certain osteoinductive effects, which have the possibility of repairing tendon-bone interface injury. OBJECTIVE: To investigate the osteoinductive effect of calcium phosphate cement II and its biomechanics analysis of repairing tendon-bone interface injury. METHODS:Five out of 35 adult healthy New Zealand white rabbits were randomly selected and their bilateral shoulder joint tendon-bone interface specimens were taken as normal control group after being sacrificed. The remaining 30 rabbits were used to make animal models of tendon-bone interface injury and then randomly divided into experimental and model groups. Rabbits in the model group had no treatment, and those in the experimental group were treated with calcium phosphate cement II. RESULTS AND CONCLUSION: After repair with calcium phosphate cement II, the injured tendon-bone interface of rabbits was

  4. Optimization of calcium phosphate fine ceramic powders preparation

    Science.gov (United States)

    Sezanova, K.; Tepavitcharova, S.; Rabadjieva, D.; Gergulova, R.; Ilieva, R.

    2013-12-01

    The effect of biomimetic synthesis method, reaction medium and further precursor treatments on the chemical and phase composition, crystal size and morphology of calcium phosphates was examined. Nanosized calcium phosphate precursors were biomimetically precipitated by the method of continuous precipitation in three types of reaction media at pH 8: (i) SBF as an inorganic electrolyte system; (ii) organic (glycerine) modified SBF (volume ratio of 1:1); (iii) polymer (10 g/l xanthan gum or 10 g/l guar gum) modified SBF (volume ratio of 1:1). After maturation (24 h) the samples were lyophilized, calcinated at 300°C for 3 hours, and washed with water, followed by new gelation, lyophilization and step-wise (200, 400, 600, 800, and 1000°C, each for 3 hours) sintering. The reaction medium influenced the chemical composition and particle size but not the morphology of the calcium phosphate powders. In all studied cases bi-phase calcium phosphate fine powders with well-shaped spherical grains, consisting of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) with a Ca/P ratio of 1.3 - 1.6 were obtained. The SBF modifiers decreased the particle size of the product in the sequence guar gum ˜ xanthan gum < glycerin < SBF medium.

  5. Rickets induced by calcium or phosphate depletion.

    OpenAIRE

    Abugassa, S.; Svensson, O.

    1990-01-01

    We studied the effects of calciopenia and phosphopenia on longitudinal growth, skeletal mineralization, and development of rickets in young Sprague-Dawley rats. At an age of 21 days, two experimental groups were given diets containing 0.02% calcium or 0.02% phosphorus; otherwise the diets were nutritionally adequate. After 7, 14, and 21 days, five animals from each group were randomly chosen. The animals were anaesthetized and blood samples were drawn for analysis of calcium, phosphorus, and ...

  6. Casein Phosphopeptide-Amorphous Calcium Phosphate Nanocomplexes: A Structural Model.

    Science.gov (United States)

    Cross, Keith J; Huq, N Laila; Reynolds, Eric C

    2016-08-01

    Tryptic digestion of the calcium-sensitive caseins yields casein phosphopeptides (CPP) that contain clusters of phosphorylated seryl residues. The CPP stabilize calcium and phosphate ions through the formation of complexes. The calcium phosphate in these complexes is biologically available for intestinal absorption and remineralization of subsurface lesions in tooth enamel. We have studied the structure of the complexes formed by the CPP with calcium phosphate using a variety of nuclear magnetic resonance (NMR) techniques. Translational diffusion measurements indicated that the β-CN(1-25)-ACP nanocomplex has a hydrodynamic radius of 1.526 ± 0.044 nm at pH 6.0, which increases to 1.923 ± 0.082 nm at pH 9.0. (1)H NMR spectra were well resolved, and (3)JH(N)-H(α) measurements ranged from a low of 5.5 Hz to a high of 8.1 Hz. Total correlation spectroscopy and nuclear Overhauser effect spectroscopy spectra were acquired and sequentially assigned. Experiments described in this paper have allowed the development of a structural model of the β-CN(1-25)-amorphous calcium phosphate nanocomplex. PMID:27434168

  7. Reinforcement of freeze-dried chitosan scaffolds with multiphasic calcium phosphate short fibers.

    Science.gov (United States)

    Mohammadi, Zahra; Mesgar, Abdorreza Sheikh-Mehdi; Rasouli-Disfani, Fariba

    2016-08-01

    The composite scaffolds of the chitosan and multiphasic calcium phosphate (HW) short fibers were prepared by freeze drying and characterized by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM and FE-SEM). The mechanical properties of the scaffolds were assessed by compression test. The incorporation of HW fibers consisting three phases of hydroxyapatite (HA), beta-tricalcium phosphate (β-TCP) and calcium pyrophosphate (CPP) into the chitosan matrices was associated with an increase in pore size, density and compressive strength and modulus, and a decrease in porosity and swelling ratio of the scaffolds. The strongest composite scaffolds in this study with a chitosan: HW fibers weight ratio of 1:1 showed a mean porosity of 69% and a mean strength and modulus of 420kPa and 3.87MPa, respectively. The in vitro bioactivity of the composites was confirmed by the formation of a calcium phosphate rich layer on the surface of soaked scaffolds in simulated body fluid. The findings of this initial work indicate that the chitosan-multiphasic calcium phosphate short fibers may be a suitable material for bone scaffolding. PMID:27179144

  8. Molecular mechanisms of crystallization impacting calcium phosphate cements

    Science.gov (United States)

    Giocondi, Jennifer L.; El-Dasher, Bassem S.; Nancollas, George H.; Orme, Christine A.

    2010-01-01

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO4·2H2O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite’s excellent biocompatibility, can be used to great benefit in making resorbable biomedical cements. To optimize cements, additives are commonly used to control crystallization kinetics and phase transformation. This paper describes the use of in situ scanning probe microscopy to investigate the role of several solution parameters and additives in brushite atomic step motion. Surprisingly, this work demonstrates that the activation barrier for phosphate (rather than calcium) incorporation limits growth kinetics and that additives such as magnesium, citrate and bisphosphonates each influence step motion in distinctly different ways. Our findings provide details of how, and where, molecules inhibit or accelerate kinetics. These insights have the potential to aid in designing molecules to target specific steps and to guide synergistic combinations of additives. PMID:20308110

  9. Elucidating the individual effects of calcium and phosphate ions on hMSCs by using composite materials.

    Science.gov (United States)

    Danoux, Charlène B S S; Bassett, David C; Othman, Ziryan; Rodrigues, Ana I; Reis, Rui L; Barralet, Jake E; van Blitterswijk, Clemens A; Habibovic, Pamela

    2015-04-01

    The biological performance of bone graft substitutes based on calcium phosphate bioceramics is dependent on a number of properties including chemical composition, porosity and surface micro- and nanoscale structure. However, in contemporary bioceramics these properties are interlinked, therefore making it difficult to investigate the individual effects of each property on cell behavior. In this study we have attempted to investigate the effects of calcium and inorganic phosphate ions independent from one another by preparing composite materials with polylactic acid (PLA) as a polymeric matrix and calcium carbonate or sodium phosphate salts as fillers. Clinically relevant bone marrow derived human mesenchymal stromal cells (hMSCs) were cultured on these composites and proliferation, osteogenic differentiation and ECM mineralization were investigated with time and were compared to plain PLA control particles. In parallel, cells were also cultured on conventional cell culture plates in media supplemented with calcium or inorganic phosphate to study the effect of these ions independent of the 3D environment created by the particles. Calcium was shown to increase proliferation of cells, whereas both calcium and phosphate positively affected alkaline phosphatase enzyme production. QPCR analysis revealed positive effects of calcium and of inorganic phosphate on the expression of osteogenic markers, in particular bone morphogenetic protein-2 and osteopontin. Higher levels of mineralization were also observed upon exposure to either ion. Effects were similar for cells cultured on composite materials and those cultured in supplemented media, although ion concentrations in the composite cultures were lower. The approach presented here may be a valuable tool for studying the individual effects of a variety of soluble compounds, including bioinorganics, without interference from other material properties. PMID:25676583

  10. Atomic structure of intracellular amorphous calcium phosphate deposits.

    Science.gov (United States)

    Betts, F; Blumenthal, N C; Posner, A S; Becker, G L; Lehninger, A L

    1975-06-01

    The radial distribution function calculated from x-ray diffraction of mineralized cytoplasmic structures isolated from the hepatopancreas of the blue crab (Callinectes sapidus) is very similar to that previously found for synthetic amorphous calcium phosphate. Both types of mineral apparently have only short-range atomic order, represented as a neutral ion cluster of about 10 A in longest dimension, whose probable composition is expressed by the formula Ca9(PO4)6. The minor differences observed are attributed to the presence in the biological mineral of significant amounts of Mg-2+ and ATP. Synthetic amorphous calcium phosphate in contact with a solution containing an amount of ATP equivalent to that of the biological mineral failed to undergo conversion to the thermodynamically more stable hydroxyapatite. The amorphous calcium phosphate of the cytoplasmic mineral granules is similarly stable, and does not undergo conversion to hydroxyapatite, presumably owing to the presence of ATP and Mg-2+, known in inhibitors of the conversion process. The physiological implications of mineral deposits consisting of stabilized calcium phosphate ion clusters are discussed.

  11. Mechanical properties of porous, electrosprayed calcium phosphate coatings

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Lommen, L.; Pooters, T.; Schoonman, J.; Jansen, J.A.

    2006-01-01

    Mechanical properties of calcium phosphate coatings (CaP), deposited using the electrostatic spray deposition (ESD) technique, have been characterized using a range of analytical techniques, including tensile testing (ASTM C633), fatigue testing (ASTM E855), and scratch testing using blunt and sharp

  12. Calcium and phosphate homeostasis: concerted interplay of new regulators.

    NARCIS (Netherlands)

    Renkema, K.Y.R.; Alexander, R.T.; Bindels, R.J.M.; Hoenderop, J.G.J.

    2008-01-01

    Calcium (Ca(2+)) and phosphate (P(i)) are essential to many vital physiological processes. Consequently the maintenance of Ca(2+) and P(i) homeostasis is essential to a healthy existence. This occurs through the concerted action of intestinal, renal, and skeletal regulatory mechanisms. Ca(2+) and P(

  13. Amorphous calcium phosphate and its application in dentistry

    Directory of Open Access Journals (Sweden)

    Sun Wei-bin

    2011-07-01

    Full Text Available Abstract Amorphous Calcium Phosphate (ACP is an essential mineral phase formed in mineralized tissues and the first commercial product as artificial hydroxyapatite. ACP is unique among all forms of calcium phosphates in that it lacks long-range, periodic atomic scale order of crystalline calcium phosphates. The X-ray diffraction pattern is broad and diffuse with a maximum at 25 degree 2 theta, and no other different features compared with well-crystallized hydroxyapatite. Under electron microscopy, its morphological form is shown as small spheroidal particles in the scale of tenths nanometer. In aqueous media, ACP is easily transformed into crystalline phases such as octacalcium phosphate and apatite due to the growing of microcrystalline. It has been demonstrated that ACP has better osteoconductivity and biodegradability than tricalcium phosphate and hydroxyapatite in vivo. Moreover, it can increase alkaline phosphatase activities of mesoblasts, enhance cell proliferation and promote cell adhesion. The unique role of ACP during the formation of mineralized tissues makes it a promising candidate material for tissue repair and regeneration. ACP may also be a potential remineralizing agent in dental applications. Recently developed ACP-filled bioactive composites are believed to be effective anti-demineralizing/remineralizing agents for the preservation and repair of tooth structures. This review provides an overview of the development, structure, chemical composition, morphological characterization, phase transformation and biomedical application of ACP in dentistry.

  14. Magnetic properties study on Fe-doped calcium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Silva, C C; Valente, M A [Physics Department (I3N), Aveiro University (Portugal); Vasconcelos, I F [Metallurgical and Materials Engineering Department, Federal University of Ceara, Campus do Pici, 714 Block, 60455-760, Fortaleza, Ceara (Brazil); Sombra, A S B [Telecommunications and Materials Science and Engineering Laboratory (LOCEM), Department of Physics, Federal University of Ceara, Campus do Pici, Postal Code 6030, 60455-760, Fortaleza, Ceara (Brazil)], E-mail: ccsilva@ua.pt, E-mail: ccsilva@fisica.ufc.br

    2009-11-15

    Calcium phosphates are very important for applications in medicine due to their properties such as biocompatibility and bioactivity. In order to enhance these properties, substitution of calcium with other ions has been proposed. Partial substitution of calcium by different ions has been made in order to improve the properties of the calcium phosphates and also to allow new applications of apatite in medicine. In this work, hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}-HAP] was prepared by high-energy dry milling (20 h) and mixed with iron oxide (5 wt.%). The mixture was calcinated at 900 deg. C for 5 h with a heating rate of 3 deg. C min{sup -1} in an attempt to introduce iron oxide into the HAP structure. The sintered sample was characterized using x-ray diffraction (XRD) and magnetization. The {sup 57}Fe-Moessbauer spectra of the calcium phosphate oxides were also measured, revealing the presence of iron in three different phases: Ca{sub 2}Fe{sub 2}O{sub 5}, Fe{sub 2}O{sub 3} and hydroxyapatite.

  15. Calcium-phosphate-osteopontin particles for caries control

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Birkedal, Henrik; Olsen, Jakob;

    2016-01-01

    Caries is caused by acid production in biofilms on dental surfaces. Preventing caries therefore involves control of microorganisms and/or the acid produced. Here, calcium-phosphate-osteopontin particles are presented as a new approach to caries control. The particles are made by co......-precipitation and designed to bind to bacteria in biofilms, impede biofilm build-up without killing the microflora, and release phosphate ions to buffer bacterial acid production if the pH decreases below 6. Analysis of biofilm formation and pH in a five-species biofilm model for dental caries showed that treatment......H always remained above 5.5. Hence, calcium-phosphate-osteopontin particles show potential for applications in caries control....

  16. Calcium-phosphate-osteopontin particles for caries control

    DEFF Research Database (Denmark)

    Schlafer, Sebastian

    Oftentimes caries lesions develop in protected sites that are difficult to access by self-performed mechanical tooth cleaning. At present, there is a growing interest in chemical adjuncts to mechanical procedures of oral hygiene that aim at biofilm control rather than biofilm eradication. Calcium......-phosphate-osteopontin particles are a new promising therapeutic approach to caries control. They are designed to bind to dental biofilms and interfere with biofilm build-up, lowering the bacterial burden on the tooth surface without affecting bacterial viability in the oral cavity. Moreover, they dissolve when pH in the biofilm...... drops to 6 or below and release buffering phosphate ions that stabilize biofilm pH above the critical level for enamel dissolution. With that twofold approach, calcium-phosphate-osteopontin particles may make a relevant contribution to clinical caries control....

  17. Formation of calcium phosphate mineral materialcontrolled by microemulsion

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to prepare calcium phosphate-based material with nano-structure and bioactivity, natural lecithin and n-tetradecane were used as the amphipile and the oil phase respectively, along with the water phase, to form a microemulsion template. Phosphate mineralization was induced and controlled by the microemulsion. The products, characterized by scanning electronic microscopy, infrared spectroscopy and X-ray diffraction analysis, are composed of lecithin and hydroxyapatite, and possess the nano-structure of sticks, balls and three-dimensional nets connected by tubes. These results show that the microemulsion can be used to control calcium phosphate mineralization for the preparation of biomimetic mineral materials with various nano-structures.

  18. Physicochemical and Microstructural Characterization of Injectable Load-Bearing Calcium Phosphate Scaffold

    Directory of Open Access Journals (Sweden)

    Mazen Alshaaer

    2013-01-01

    Full Text Available Injectable load-bearing calcium phosphate scaffolds are synthesized using rod-like mannitol grains as porogen. These degradable injectable strong porous scaffolds, prepared by calcium phosphate cement, could represent a valid solution to achieve adequate porosity requirements while providing adequate support in load-bearing applications. The proposed process for preparing porous injectable scaffolds is as quick and versatile as conventional technologies. Using this method, porous CDHA-based calcium phosphate scaffolds with macropores sizes ranging from 70 to 300 μm, micropores ranging from 5 to 30 μm, and 30% open macroporosity were prepared. The setting time of the prepared scaffolds was 15 minutes. Also their compressive strength and e-modulus, 4.9 MPa and 400 MPa, respectively, were comparable with those of the cancellous bone. Finally, the bioactivity of the scaffolds was confirmed by cell growth with cytoplasmic extensions in the scaffolds in culture, demonstrating that the scaffold has a potential for MSC seeding and growth architecture. This combination of an interconnected macroporous structure with pore size suitable for the promotion of cell seeding and proliferation, plus adequate mechanical features, represents a porous scaffold which is a promising candidate for bone tissue engineering.

  19. Synthesis and characterization of nanocomposite powders of calcium phosphate/silica-gel

    International Nuclear Information System (INIS)

    In the recent years ceramics of calcium phosphate are pointed out as an outstanding material in substitution and regeneration in defects from osseous tissue, in reason of their similar mineralogical characteristics of apatite of bone structure. However, the challenge with phosphate calcium ceramics find out about the mechanical properties and the development of biomaterials similar of the bone structure, what sometimes is not so easy, about fragile materials. The aim of this work focused in synthesis and characterization nanocomposites powders of calcium phosphate/silica-gel with percentages 1, 2, 3 e 5% of nanometric silica. The method synthesis used for the compositions elaboration was dissolution-precipitation. The presented results are related with the optimization to method elaboration of nanostructured powders, the mineralogical characterization with X-ray diffraction, thermal behavior with thermal differential analysis, differential scanning calorimetry here is ADT and dilatometer. The scanning electronic microscopy was used to help of morphological characterization the nanostructured powders and the surfaces from body test recovered from the mechanical test. (author)

  20. 活性磷酸钙复合明胶海绵的制备及对骨缺损修复的实验研究%Bioactive calcium phosphate mineralized collagen sponge for bone regeneration: preparation and study on the repairing of bone defect

    Institute of Scientific and Technical Information of China (English)

    张珂; 王淑敏; 蔡意达; 周鸿国; 俞立英

    2012-01-01

    than precipitation method.The histological observations showed calcified newly formed bone surrounding surface-modified collagen sponges.Massive osteocytes existed.Conclusions The collagen sponges mineralized by calcium phosphate has better properties of bone formation.Surface-modified collagen sponge as a scaffold material is a promising biomaterial.

  1. Development of calcium phosphate based bioceramics

    Indian Academy of Sciences (India)

    Amit Sinha; A Ingle; K R Munim; S N Vaidya; B P Sharma; A N Bhisey

    2001-12-01

    Two bioceramics (Ca–P–O glass and A–W glass ceramic) were produced using conventional methods of ceramic technology. X-ray powder diffraction patterns were used for identifying the phases and 3-point bend test was carried out for the determination of fracture strength of the bioceramics. Biocompatibility of both ceramics was evaluated using animal model experiments. Histological studies showed that A–W glass ceramic implanted in the tibia of rat formed an intimate contact with newly grown bone and provided enough strength to the bone to bear the animal weight. Implants made of Ca–P–O glass was almost fully resorbed and was replaced by new bone. The implants made of both the bioceramics were biocompatible and did not exhibit any kind of adverse effect to the surrounding tissues.

  2. Impact of endocrine hyperfunction and phosphate wasting on bone in McCune-Albright syndrome.

    Science.gov (United States)

    Lala, R; Matarazzo, P; Andreo, M; Defilippi, C; de Sanctis, C

    2002-01-01

    Skin dysplasia, as café-au-lait spots, bone fibrous dysplasia and peripheral endocrinopathies are the main clinical features of McCune-Albright syndrome (MAS). This illness is due to activating mutations of the Gsalpha protein and is spread with a mosaic pattern in affected tissues that consist of intermixed areas of normal and mutated cells. Peripheral endocrine secretion, free of hypothalamic pituitary control, is the hallmark of the endocrine syndromes: precocious puberty, Cushing's syndrome, hyperthyroidism and gigantism/acromegaly. In addition, phosphate wasting as hyperphosphaturia is often present. The impact of hormonal hypersecretion and phosphate loss on the bones of patients with MAS is poorly understood both in normal and fibrous bone tissue. As hypercortisolism and hyperthyroidism increase bone resorption, hyperestrogenism and growth hormone hypersecretion stimulate bone growth and mineralization, and phosphate wasting reduces bone mineral content. All these actions can be exerted at varying times and degrees in a single patient on lesional and non-lesional bones. Sonographic evidence of multiple diffused hyperechogenic spots in the testes of patients with MAS do not seem to be related to alterations in calcium-phosphate metabolism but rather to zonal dysplasia/hyperplasia of testicular tissue. PMID:12199350

  3. A brief review of calcium phosphate conversion coating on magnesium and its alloys

    Science.gov (United States)

    Zaludin, Mohd Amin Farhan; Jamal, Zul Azhar Zahid; Jamaludin, Shamsul Baharin; Derman, Mohd Nazree

    2016-07-01

    Recent developments have shown that magnesium is a promising candidate to be used as a biomaterial. Owing to its light weight, biocompatibility and compressive strength comparable with natural bones makes magnesium as an excellent choice for biomaterial. However, high reactivity and low corrosion resistance properties have restricted the application of magnesium as biomaterials. At the moment, several strategies have been developed to solve this problem. Surface modification of magnesium is one of the popular solutions to solve the problem. Among many techniques developed in the surface modification, conversion coating method is one of the simple and effective techniques. From various types of conversion coating, calcium phosphate-based conversion coating is the most suitable for biomedical fields. This paper reviews some studies on calcium phosphate coating on Mg and its alloys via chemical conversion method and discusses some factors determining the coating performance.

  4. Preparation of novel bioactive nano-calcium phosphate-hydrogel composites

    Energy Technology Data Exchange (ETDEWEB)

    Juhasz, Judith A; Best, Serena M; Bonfield, William, E-mail: jaj33@cam.ac.u [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)

    2010-02-15

    Nano-sized hydroxyapatite (nHA) and carbonate-substituted hydroxyapatite (nCHA) particles were incorporated into a poly-2-hydroxyethylmethacrylate/polycaprolactone (PHEMA/PCL) hydrogel at a filler content of 10 wt%. Fourier transform infrared absorption, transmission electron microscopy, x-ray diffraction and scanning electron microscopy were used to analyse the physical and chemical characteristics of the calcium phosphate fillers and resultant composites. Nano-sized calcium phosphate particles were produced with a needle-like morphology, average length of 50 nm and an aspect ratio of 3. The nanoparticles were uniformly distributed in the polymer matrix. The addition of both HA and CHA in nano-form enhanced the bioactivity and biocompatibility of the PHEMA/PCL matrix. The carbonate-substitution has allowed for improved bioactivity and biocompatibility of the resultant composite, indicating the potential of this material for use in bone tissue engineering.

  5. Development of a fully injectable calcium phosphate cement for orthopedic and dental applications

    Indian Academy of Sciences (India)

    Manoj Komath; H K Varma

    2003-06-01

    A study on the development of a fully injectable calcium phosphate cement for orthopedic and dental applications is presented. The paper describes its characteristic properties including results of bio- compatibility studies. A conventional two-component calcium phosphate cement formulation (having a powder part containing dry mixture of acidic and basic calcium phosphate particles and a liquid part containing phosphate solution) is modified with a biocompatible gelling agent, to induce flow properties and cohesion. The quantity of the gelling agent is optimized to get a viscous paste, which is smoothly injectable through an 18-gauge needle, with clinically relevant setting parameters. The new formulation has a setting time of 20 min and a compressive strength of 11 MPa. The X-ray diffraction, Fourier transform infrared spectrometry, and energy dispersive electron microprobe analyses showed the phase to be hydroxyapatite, the basic bone mineral. Scanning electron microscopy revealed a porous structure with particle sizes of a few micrometers. The cement did not show any appreciable dimensional or thermal change during setting. The injectability is estimated by extruding through needle and the cohesive property is assessed by water contact method. The cement passed the in vitro biocompatibility screening (cytotoxicity and haemolysis) tests.

  6. Diagnosis and clinical manifestations of calcium pyrophosphate and basic calcium phosphate crystal deposition diseases.

    Science.gov (United States)

    Ea, Hang-Korng; Lioté, Frédéric

    2014-05-01

    Basic calcium phosphate and pyrophosphate calcium crystals are the 2 main calcium-containing crystals that can deposit in all skeletal tissues. These calcium crystals give rise to numerous manifestations, including acute inflammatory attacks that can mimic alarming and threatening differential diagnoses, osteoarthritis-like lesions, destructive arthropathies, and calcific tendinitis. Awareness of uncommon localizations and manifestations such as intraspinal deposition (eg, crowned dens syndrome, tendinitis of longus colli muscle, massive cervical myelopathy compression) prevents inappropriate procedures and cares. Coupling plain radiography, ultrasonography, computed tomography, and synovial fluid analysis allow accurate diagnosis by directly or indirectly identifying the GRAAL of microcrystal-related symptoms.

  7. In vitro study on biomineralization of biphasic calcium phosphate biocomposite crosslinked with hydrolysable tannins of Terminalia chebula

    Indian Academy of Sciences (India)

    G Krithiga; Antaryami Jena; P Selvamani; T P Sastry

    2011-06-01

    In this study, we report the preparation of a bone graft material, having cylindrical shape, containing biphasic calcium phosphate (BCP), gelatin (G), chitosan (C) and Terminalia chebula (TC) extract. TC extract was used as a crosslinker that gives stability to bone graft when it is placed in SBF. The graft was stable in the SBF solution for 21 days and FTIR, SEM, EDX and thermogravimetric studies revealed the ossification of the implant.

  8. Biomechanical changes of injured rabbit tendon-to-bone interface during repair with calcium phosphate cement-II%自固化磷酸钙人工骨Ⅱ修复兔腱-骨损伤的生物力学变化

    Institute of Scientific and Technical Information of China (English)

    张喜海; 黄树华; 李森; 鲁晓波

    2014-01-01

    背景:磷酸钙人工骨与重组人骨形态发生蛋白2在实验中均有成骨诱导作用,有修复腱骨界面损伤的可能。目的:评估自固化磷酸钙人工骨Ⅱ(含重组人骨形态发生蛋白2)修复兔肩袖腱-骨界面损伤后的生物力学变化。方法:取27只成年健康家兔,其中3只直接取双侧肩关节腱-骨界面标本作为正常组,余下的24只家兔双侧肩关节接受兔肩袖急性断裂腱-骨止点重建手术,术中实验组12只填塞自固化磷酸钙人工骨Ⅱ,对照组12只不填塞任何药物。分别于术后2,4,8周采集标本行生物力学测试。结果与结论:实验组各时间点肩袖腱-骨界面最大抗拉强度均高于对照组(P <0.001),但低于正常组(P <0.001);实验组术后8周肩袖腱-骨界面刚度高于对照组(P <0.001),但低于正常组(P <0.001)。表明自固化磷酸钙人工骨Ⅱ可以在术后早期提高兔腱-骨界面的最大抗拉强度和刚度,增强腱-骨界面结合力,促进腱骨界面愈合。%BACKGROUND:Calcium phosphate cement and recombinant human bone morphogenetic protein-2 both have bone osteoinductivity. Maybe both of them could promote repair of tendon-to-bone interface damage. OBJECTIVE:To evaluate the effect of calcium phosphate cement-II containing recombinant human bone morphogenetic protein-2 on tendon-to-bone interface healing after rotator cuff injury . METHODS: Twenty-seven adult healthy rabbits were enroled in the study. The tendon-to-bone interface of the bilateral shoulder joints was taken from three rabbits as normal group, and the bilateral shoulder joints of the other 24 rabbits were subjected to acute rupture of the rotator cuff and tendon-to-bone reconstructive surgery as experimental group (n=12) and control group (n=12). Rabbits in the experimental group were treated with calcium phosphate cement-II, while those in the control group treated with nothing. Specimens were colected at 2, 4, 8

  9. Effect of different calcium phosphate scaffold ratios on odontogenic differentiation of human dental pulp cells

    Energy Technology Data Exchange (ETDEWEB)

    AbdulQader, Sarah Talib [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Department of Pedodontic and Preventive Dentistry, College of Dentistry, University of Baghdad, Baghdad (Iraq); Kannan, Thirumulu Ponnuraj, E-mail: kannan@usm.my [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Rahman, Ismail Ab [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Ismail, Hanafi [School of Materials and Minerals Resource Engineering, Universiti Sains Malaysia, 14300 Penang (Malaysia); Mahmood, Zuliani [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2015-04-01

    Calcium phosphate (CaP) scaffolds have been widely and successfully used with osteoblast cells for bone tissue regeneration. However, it is necessary to investigate the effects of these scaffolds on odontoblast cells' proliferation and differentiation for dentin tissue regeneration. In this study, three different hydroxyapatite (HA) to beta tricalcium phosphate (β-TCP) ratios of biphasic calcium phosphate (BCP) scaffolds, BCP20, BCP50, and BCP80, with a mean pore size of 300 μm and 65% porosity were prepared from phosphoric acid (H{sub 2}PO{sub 4}) and calcium carbonate (CaCO{sub 3}) sintered at 1000 °C for 2 h. The extracts of these scaffolds were assessed with regard to cell viability and differentiation of odontoblasts. The high alkalinity, more calcium, and phosphate ions released that were exhibited by BCP20 decreased the viability of human dental pulp cells (HDPCs) as compared to BCP50 and BCP80. However, the cells cultured with BCP20 extract expressed high alkaline phosphatase activity and high expression level of bone sialoprotein (BSP), dental matrix protein-1 (DMP-1), and dentin sialophosphoprotein (DSPP) genes as compared to that cultured with BCP50 and BCP80 extracts. The results highlighted the effect of different scaffold ratios on the cell microenvironment and demonstrated that BCP20 scaffold can support HDPC differentiation for dentin tissue regeneration. - Highlights: • BCPs of different HA/β-TCP ratios influence cell microenvironment. • BCP20 decreases cell viability of HDPCs as compared to BCP50 and BCP80. • HDPCs cultured with BCP20 express highest ALP activity. • HDPCs cultured with BCP20 up-regulate BSP, DMP-1 and DSPP gene expressions. • BCP20 can support HDPC differentiation for dentin tissue regeneration.

  10. Effect of different calcium phosphate scaffold ratios on odontogenic differentiation of human dental pulp cells

    International Nuclear Information System (INIS)

    Calcium phosphate (CaP) scaffolds have been widely and successfully used with osteoblast cells for bone tissue regeneration. However, it is necessary to investigate the effects of these scaffolds on odontoblast cells' proliferation and differentiation for dentin tissue regeneration. In this study, three different hydroxyapatite (HA) to beta tricalcium phosphate (β-TCP) ratios of biphasic calcium phosphate (BCP) scaffolds, BCP20, BCP50, and BCP80, with a mean pore size of 300 μm and 65% porosity were prepared from phosphoric acid (H2PO4) and calcium carbonate (CaCO3) sintered at 1000 °C for 2 h. The extracts of these scaffolds were assessed with regard to cell viability and differentiation of odontoblasts. The high alkalinity, more calcium, and phosphate ions released that were exhibited by BCP20 decreased the viability of human dental pulp cells (HDPCs) as compared to BCP50 and BCP80. However, the cells cultured with BCP20 extract expressed high alkaline phosphatase activity and high expression level of bone sialoprotein (BSP), dental matrix protein-1 (DMP-1), and dentin sialophosphoprotein (DSPP) genes as compared to that cultured with BCP50 and BCP80 extracts. The results highlighted the effect of different scaffold ratios on the cell microenvironment and demonstrated that BCP20 scaffold can support HDPC differentiation for dentin tissue regeneration. - Highlights: • BCPs of different HA/β-TCP ratios influence cell microenvironment. • BCP20 decreases cell viability of HDPCs as compared to BCP50 and BCP80. • HDPCs cultured with BCP20 express highest ALP activity. • HDPCs cultured with BCP20 up-regulate BSP, DMP-1 and DSPP gene expressions. • BCP20 can support HDPC differentiation for dentin tissue regeneration

  11. Low temperature method for the production of calcium phosphate fillers

    Directory of Open Access Journals (Sweden)

    Nastro Alfonso

    2004-03-01

    Full Text Available Abstract Background Calcium phosphate manufactured samples, prepared with hydroxyapatite, are used as either spacers or fillers in orthopedic surgery, but these implants have never been used under conditions of mechanical stress. Similar conditions also apply with cements. Many authors have postulated that cements are a useful substitute material when implanted in vivo. The aim of this research is to develop a low cristalline material similar to bone in porosity and cristallinity. Methods Commercial hydroxyapatite (HAp and monetite (M powders are mixed with water and compacted to produce cylindrical samples. The material is processed at a temperature of 37–120 degrees C in saturated steam to obtain samples that are osteoconductive. The samples are studied by X-ray powder diffraction (XRD, Vickers hardness test (HV, scanning electron microscopy (SEM, and porosity evaluation. Results The X-ray diffractions of powders from the samples show patterns typical of HAp and M powders. After thermal treatment, no new crystal phase is formed and no increase of the relative intensity of the peaks is obtained. Vicker hardness data do not show any relationship with treatment temperature. The total porosity decreases by 50–60% according to the specific thermal treatment. Scanning electron microscopy of the surfaces of the samples with either HAp 80%-M 20% (c or Hap 50%-M 50% (f, show cohesion of the powder grains. Conclusions The dissolution-reprecipitation process is more intesive in manufactured samples (c and (f, according to Vickers hardness data. The process occurs in a steam saturated environment between 37 degrees and 120 degrees C. (c (f manufactured samples show pore dimension distributions useful to cellular repopulation in living tissues.

  12. Preparation and biological efficacy of haddock bone calcium tablets

    Institute of Scientific and Technical Information of China (English)

    霍健聪; 邓尚贵; 谢超; 童国忠

    2010-01-01

    To investigate the possible use of waste products obtained after processing haddock, the present study prepared haddock bone calcium powder by NaOH and ethanol soaking (alkalinealcohol method) and prepared haddock bone calcium tablets using the powder in combination with appropriate excipients. The biological efficacy of the haddock bone calcium tablets was investigated using Wistar rats as an experiment model. Results show that the optimal parameters for the alkalinealcohol method are: NaOH concentration 1...

  13. Acid gelation of colloidal calcium phosphate-depleted preheated milk

    OpenAIRE

    Famelart, Marie-Hélène; Gauvin, Géraldine; Paquet, Denis; Brulé, Gérard

    2009-01-01

    Abstract – This study aimed at understanding the role of colloidal calcium phosphate (CCP) in acid gelation of milk. Milks were depleted in Calcium (Ca) by dialysis against milk permeate containing a cation-exchange resin. Dialysed milks were then heated (90 °C-10 min) and acidgelled at 42 °C with a yoghurt culture. Minerals, total and soluble protein contents, pH and optical density were measured in unheated and heated dialysed milk, together with diameters and ζ-potentials of particles. Dia...

  14. The size of surface microstructures as an osteogenic factor in calcium phosphate ceramics.

    Science.gov (United States)

    Zhang, Jingwei; Luo, Xiaoman; Barbieri, Davide; Barradas, Ana M C; de Bruijn, Joost D; van Blitterswijk, Clemens A; Yuan, Huipin

    2014-07-01

    The microporosity of calcium phosphate (CaP) ceramics has been shown to have an essential role in osteoinduction by CaP ceramics after ectopic implantation. Here we show that it is not the microporosity but the size of surface microstructural features that is the most likely osteogenic factor. Two tricalcium phosphate (TCP) ceramics, namely TCP-S and TCP-B, were fabricated with equivalent chemistry and similar microporosity but different sizes of surface microstructural features. TCP-S has a grain size of 0.99 ± 0.20 μm and a micropore size of 0.65 ± 0.25 μm, while TCP-B displays a grain size of 3.08 ± 0.52 μm and a micropore size of 1.58 ± 0.65 μm. In vitro, both cell proliferation and osteogenic differentiation were significantly enhanced when human bone marrow stromal cells were cultured on TCP-S without any osteogenic growth factors, compared to TCP-B ceramic granules. The possible involvement of direct contact between cells and the TCP ceramic surface in osteogenic differentiation is also shown with a trans-well culture model. When the ceramic granules were implanted in paraspinal muscle of dogs for 12 weeks, abundant bone was formed in TCP-S (21 ± 10% bone in the available space), whereas no bone was formed in any of the TCP-B implants. The current in vitro and in vivo data reveal that the readily controllable cue, i.e. the size of the surface microstructure, could be sufficient to induce osteogenic differentiation of mesenchymal stem cells, ultimately leading to ectopic bone formation in calcium phosphate ceramics.

  15. A safer disposal of hazardous phosphate coating sludge by formation of an amorphous calcium phosphate matrix.

    Science.gov (United States)

    Navarro-Blasco, I; Duran, A; Pérez-Nicolás, M; Fernández, J M; Sirera, R; Alvarez, J I

    2015-08-15

    Phosphate coating hazardous wastes originated from the automotive industry were efficiently encapsulated by an acid-base reaction between phosphates present in the sludge and calcium aluminate cement, yielding very inert and stable monolithic blocks of amorphous calcium phosphate (ACP). Two different compositions of industrial sludge were characterized and loaded in ratios ranging from 10 to 50 wt.%. Setting times and compressive strengths were recorded to establish the feasibility of this method to achieve a good handling and a safe landfilling of these samples. Short solidification periods were found and leaching tests showed an excellent retention for toxic metals (Zn, Ni, Cu, Cr and Mn) and for organic matter. Retentions over 99.9% for Zn and Mn were observed even for loadings as high as 50 wt.% of the wastes. The formation of ACP phase of low porosity and high stability accounted for the effective immobilization of the hazardous components of the wastes. PMID:26024992

  16. Formation and thermal studies of calcium phosphate glasses

    International Nuclear Information System (INIS)

    Calcium Phosphate based glasses and glass ceramics are known for their bio- active nature. Thermal behaviour of three compositions of CaO-Na/sub 2/O-SiO/sub 2/-P/sub 2/O/sub 5/ glass system were studied. All glasses were clear and stable. Characteristic temperatures i.e. glass transition, glass softening temperature and liquids temperatures were determined by differential thermal analyzer and dilatometer. (author)

  17. Calcium Phosphate Coating over Silk Fibroin Film by Biomimetic Methods

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To investigate the biomineralization behavior of silk fibroin and to valuate the biodegradation and biocompatibility of the hybrid biomaterial, the calcium phosphate deposits were identified with SEM, EDX,XRD and FTIR. The results reveal that supersaturated calcification solution is an effective method for the mineralization of fibroin film. Enzymatic degradation experiment demonstrates the biodegradability of the composites. Osteoblasts incubation shows an excellent cytocompatibility on the mineralized fibroin films.

  18. Aggregation of Calcium Phosphate and Oxalate Phases in the Formation of Renal Stones

    OpenAIRE

    Xie, Baoquan; Halter, Timothy J.; Borah, Ballav M.; Nancollas, George H.

    2014-01-01

    The majority of human kidney stones are comprised of multiple calcium oxalate monohydrate (COM) crystals encasing a calcium phosphate nucleus. The physiochemical mechanism of nephrolithiasis has not been well determined on the molecular level; this is crucial to the control and prevention of renal stone formation. This work investigates the role of phosphate ions on the formation of calcium oxalate stones; recent work has identified amorphous calcium phosphate (ACP) as a rapidly forming initi...

  19. Tuning the Degradation Rate of Calcium Phosphate Cements by Incorporating Mixtures of Polylactic-co-Glycolic Acid Microspheres and Glucono-Delta-Lactone Microparticles

    NARCIS (Netherlands)

    Sariibrahimoglu, K.; An, J.; Oirschot, B.A.J.A. van; Nijhuis, A.W.G.; Eman, R.M.; Alblas, J.; Wolke, J.G.C.; Beucken, J.J.J.P van den; Leeuwenburgh, S.C.G.; Jansen, J.A.

    2014-01-01

    Calcium phosphate cements (CPCs) are frequently used as synthetic bone graft materials in view of their excellent osteocompatibility and clinical handling behavior. Hydroxyapatite-forming CPCs, however, degrade at very low rates, thereby limiting complete bone regeneration. The current study has inv

  20. The influence of Sr content in calcium phosphate coatings

    International Nuclear Information System (INIS)

    In this study calcium phosphate coatings with different amounts of strontium (Sr) were prepared using a biomineralization method. The incorporation of Sr changed the composition and morphology of coatings from plate-like to sphere-like morphology. Dissolution testing indicated that the solubility of the coatings increased with increased Sr concentration. Evaluation of extracts (with Sr concentrations ranging from 0 to 2.37 μg/mL) from the HA, 0.06Sr, 0.6Sr, and 1.2Sr coatings during in vitro cell cultures showed that Sr incorporation into coatings significantly enhanced the ALP activity in comparison to cells treated with control and HA eluted media. These findings show that calcium phosphate coatings could promote osteogenic differentiation even in a low amount of strontium. - Highlights: • Calcium phosphate coating doping with low Sr contents was prepared via a biomineralization process. • The solubility of the coatings increased with increased Sr concentration. • Present findings show the potential that Sr has on promoting osteogenic differentiation even in a low amount

  1. The influence of Sr content in calcium phosphate coatings

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, Carl [Department of Biomaterials, Institute for Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Gothenburg (Sweden); BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Pujari-Palmer, Shiuli; Hoess, Andreas; Ott, Marjam [Applied Materials Science, Department of Engineering Sciences, Uppsala University, Uppsala (Sweden); Engqvist, Håkan [BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Applied Materials Science, Department of Engineering Sciences, Uppsala University, Uppsala (Sweden); Xia, Wei, E-mail: wei.xia@angstrom.uu.se [BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg (Sweden); Applied Materials Science, Department of Engineering Sciences, Uppsala University, Uppsala (Sweden)

    2015-08-01

    In this study calcium phosphate coatings with different amounts of strontium (Sr) were prepared using a biomineralization method. The incorporation of Sr changed the composition and morphology of coatings from plate-like to sphere-like morphology. Dissolution testing indicated that the solubility of the coatings increased with increased Sr concentration. Evaluation of extracts (with Sr concentrations ranging from 0 to 2.37 μg/mL) from the HA, 0.06Sr, 0.6Sr, and 1.2Sr coatings during in vitro cell cultures showed that Sr incorporation into coatings significantly enhanced the ALP activity in comparison to cells treated with control and HA eluted media. These findings show that calcium phosphate coatings could promote osteogenic differentiation even in a low amount of strontium. - Highlights: • Calcium phosphate coating doping with low Sr contents was prepared via a biomineralization process. • The solubility of the coatings increased with increased Sr concentration. • Present findings show the potential that Sr has on promoting osteogenic differentiation even in a low amount.

  2. Crystallized nano-sized alpha-tricalcium phosphate from amorphous calcium phosphate: microstructure, cementation and cell response.

    Science.gov (United States)

    Vecbiskena, Linda; Gross, Karlis Agris; Riekstina, Una; Yang, Thomas Chung-Kuang

    2015-04-01

    New insight on the conversion of amorphous calcium phosphate (ACP) to nano-sized alpha tricalcium phosphate (α-TCP) provides a faster pathway to calcium phosphate bone cements. In this work, synthesized ACP powders were treated with either water or ethanol, dried, crystallized between 700 and 800 °C, and then cooled at different cooling rates. Particle size was measured in a scanning electron microscope, but crystallite size calculated by Rietveld analysis. Phase composition and bonding in the crystallized powder was assessed by x-ray diffraction and Fourier-transform infrared spectroscopy. Results showed that 50 nm sized α-TCP formed after crystallization of lyophilized powders. Water treated ACP retained an unstable state that may allow ordering to nanoapatite, and further transition to β-TCP after crystallization and subsequent decomposition. Powders treated with ethanol, favoured the formation of pure α-TCP. Faster cooling limited the growth of β-TCP. Both the initial contact with water and the cooling rate after crystallization dictated β-TCP formation. Nano-sized α-TCP reacted faster with water to an apatite bone cement than conventionally prepared α-TCP. Water treated and freeze-dried powders showed faster apatite cement formation compared to ethanol treated powders. Good biocompatibility was found in pure α-TCP nanoparticles made from ethanol treatment and with a larger crystallite size. This is the first report of pure α-TCP nanoparticles with a reactivity that has not required additional milling to cause cementation. PMID:25886478

  3. Modulating calcium phosphate formation using CO2 laser engineering of a polymeric material

    International Nuclear Information System (INIS)

    The use of simulated body fluid (SBF) is widely used as a screening technique to assess the ability of materials to promote calcium phosphate formation. This paper details the use of CO2 laser surface treatment of nylon® 6,6 to modulate calcium phosphate formation following immersion in SBF for 14 days. Through white light interferometry (WLI) it was determined that the laser surface processing gave rise to maximum Ra and Sa parameters of 1.3 and 4.4 μm, respectively. The use of X-ray photoelectron spectroscopy (XPS) enabled a maximum increase in surface oxygen content of 5.6%at. to be identified. The laser-induced surface modifications gave rise to a modulation in the wettability characteristics such that the contact angle, θ, decreased for the whole area processed samples, as expected, and increased for the patterned samples. The increase in θ can be attributed to a transition in wetting nature to a mixed-state wetting regime. It was seen for all samples that calcium phosphate formed on each surface following 14 days. The largest increase in mass, Δg, owed to calcium phosphate formation, was brought about by the whole area processed sample irradiated with a fluence of 51 J cm−2. No correlation between the calcium phosphate formation and the laser patterned surface properties was determined due to the likely affect of the mixed-state wetting regime. Strong correlations between θ, the surface energy parameters and the calcium phosphate formation for the whole area processed samples allow one to realize the potential for this surface treatment technique in predicting the bone forming ability of laser processed materials. - Highlights: ► Surface modifications brought about a modulation in the wetting of nylon 6,6. ► An increase in θ can be attributed to a mixed-state wetting regime. ► Laser surface treatment modulated the ability to promote apatite formation. ► Mixed-state wetting regime affected the promotion of uniform apatite formation. ► Method

  4. Tri-calcium phosphate (ß-TCP) can be artificially synthesized by recycling dihydrate gypsum hardened.

    Science.gov (United States)

    Han-Cheol, Cho; Hori, Masaharu; Yoshida, Takakazu; Yamada, Naoko; Komada, Yuko; Tamaki, Yukimichi; Miyazaki, Takashi

    2014-01-01

    Calcium phosphate is known as a major component of biological hard tissues. This study aimed to produce calcium phosphate by recycling kneaded surplus gypsum. β-dihydrate gypsum was derived from commercial dental β-hemihydrate gypsum, which was mechanically powdered and mixed with the liquid component of a commercial zinc phosphate cement. This mixture was fired at 1,200°C and evaluated by XRD analysis, thermal analysis and scanning electron microscopy (SEM). An acceptable ratio of mixing was 4 g of β-dihydrate gypsum powder to 1.5 mL of phosphoric acid liquid. XRD peaks were monotonic below 800°C, but new ß-TCP was formed by firing at 900°C or more, although TG-DTA analysis of synthetic ß-TCP suggested that some residual dihydrate gypsum remained in the sample. SEM images indicated a fused-block bone-like structure covered with phosphorus and calcium. These results suggest that production of synthetic β-TCP is possible through ecological techniques using recycled materials. PMID:25483384

  5. Importance of FTIR Spectra Deconvolution for the Analysis of Amorphous Calcium Phosphates

    OpenAIRE

    Brangule, A; Gross, K.

    2015-01-01

    This work will consider Fourier transform infrared spectroscopy – diffuse reflectance infrared reflection (FTIR-DRIFT) for collecting the spectra and deconvolution to identify changes in bonding as a means of more powerful detection. Spectra were recorded from amorphous calcium phosphate synthesized by wet precipitation, and from bone. FTIR-DRIFT was used to study the chemical environments of PO4, CO3 and amide. Deconvolution of spectra separated overlapping bands in the ʋ4PO4, ʋ2CO3, ʋ3CO...

  6. Artrodese na coluna cervical utilizando SICAP como substituto de enxerto ósseo Artrodesis en la columna cervical utilizando SICAP como sustituto de injerto óseo Cervical spine fusion utilizing silicated calcium phosphate bone graft substitute (SICAP

    Directory of Open Access Journals (Sweden)

    Juliano Fratezi

    2011-01-01

    Tech EE.UU, Reino Unido es un injerto óseo compuesto de calcio-fosfato con una sustitución de silicato en la estructura química, con una estructura tridimensional que parece hueso natural. MÉTODOS: 19 pacientes fueron sometidos a fusión ósea cervical y analizados retrospectivamente. La evaluación radiográfica y la evaluación clínica fueron realizadas utilizandose el cuestionario Neck Disability Index y la escala análoga del dolor (VAS pre y postoperación. RESULTADOS: El período promedio de seguimiento postoperatorio fue de 14 meses ± 5 meses (7-30 meses. Once pacientes fueron sometidos a fusión vía anterior; 5 pacientes vía posterior y 3 pacientes vía anterior y posterior. La revisión radiográfica mostró 19/19 (100% de fusión ósea, ningún caso presentó subsidencia, rotura o soltura de material de implante o movimiento en los niveles fusionados. Ningún ejemplo de osificación heterotópica o de crecimiento óseo intracanal fue observado. Clínicamente, el promedio de las puntuaciones del Neck Disability disminuyeron 13,3 puntos (promedio preop. de 34,5, postop. de 21,2, mejora de 39%, el promedio de VAS para dolor cervical disminuyó 2 puntos (2,7 preop. para 0,7 postop.; mejora de 74,1%. No fueron observadas complicaciones como infección, osteólisis o edema excesivo de las partes blandas. CONCLUSIÓN: Los resultados preliminares obtenidos en esta serie feuron estimulantes con el uso de SICaP como injerto óseo, con sólida fusión ósea obtenida en todos los casos y sin formación de osificación heterotópica o crecimiento de hueso intracanal. SIcaP demuestra ser un sustituto confiable para el injerto óseo autólogo en la columna cervical.OBJECTIVE: Bone graft substitutes have been developed to obviate the need for autograft from the iliac crest and its resultant complications. SiCaP (Actifuse, ApaTech US, UK is a calcium phosphate bone graft substitute with selective controlled silicate substitution in a patented 3-dimensional structure

  7. Formation of calcium phosphates by vapour diffusion in highly concentrated ionic micro-droplets

    Energy Technology Data Exchange (ETDEWEB)

    Iafisco, M. [Alma Mater Studiorum Universita di Bologna, Dipartimento di Chimica ' ' G. Ciamician' ' , Via Selmi 2, 40126 Bologna (Italy); Universita del Piemonte Orientale, Dipartimento di Scienze Mediche, Via Solaroli 4, 28100 Novara (Italy); Delgado-Lopez, J.M.; Gomez-Morales, J.; Hernandez-Hernandez, M.A.; Rodriguez-Ruiz, I. [Laboratorio de Estudios Cristalograficos, IACT CSIC-UGR, Edificio Lopez Neyra, Avenida del Conocimiento, s/n 18100 Armilla (Spain); Roveri, N. [Alma Mater Studiorum Universita di Bologna, Dipartimento di Chimica ' ' G. Ciamician' ' , Via Selmi 2, 40126 Bologna (Italy)

    2011-08-15

    In this work we have used the sitting drop vapour diffusion technique, employing the ''crystallization mushroom '' to analyze the evolution of calcium phosphate crystallization in micro-droplets containing high initial concentrations of Ca{sup 2+} and HPO{sub 4}{sup 2-}. The decomposition of NH{sub 4}HCO{sub 3} solution produces vapours of NH{sub 3} and CO{sub 2} which diffuse through the droplets containing an aqueous solution of Ca(CH{sub 3}COO){sub 2} and (NH{sub 4}){sub 2}HPO{sub 4}. The result is the increase of pH by means of the diffusion of NH{sub 3} gas and the doping of the calcium phosphate with CO{sub 3}{sup 2-} ions by means of the diffusion of CO{sub 2} gas. The pH of the crystallization process is monitored and the precipitates at different times are characterized by XRD, FTIR, TGA, SEM and TEM techniques. The slow increase of pH and the high concentration of Ca{sup 2+} and HPO{sub 4}{sup 2-} in the droplets induce the crystallization of three calcium phosphate phases: dicalcium phosphate dihydrate (DCPD, brushite), octacalcium phosphate (OCP) and carbonate-hydroxyapatite (HA). The amount of HA nanocrystals with needle-like morphology and dimensions of about 100 nm, closely resembling the inorganic phase of bones, gradually increases, with the precipitation time up to 7 days, whereas the amount of DCPD, growing along the b axis, increases up to 3 days. Then, DCDP crystals start to hydrolyze yielding OCP nanoribbons and HA nanocrystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Calcium phosphate granulation in anaerobic treatment of black water: a new approach to phosphorus recovery

    NARCIS (Netherlands)

    Tervahauta, T.H.; Weijden, van der R.D.; Flemming, R.L.; Hernández, L.; Zeeman, G.; Buisman, C.J.N.

    2014-01-01

    Recovery of phosphorus from wastewater as calcium phosphate could diminish the need for mining of scarce phosphate rock resources. This study introduces a novel approach to phosphorus recovery by precipitation of calcium phosphate granules in anaerobic treatment of black water. The granules formed i

  9. Short-term in vivo evaluation of zinc-containing calcium phosphate using a normalized procedure

    Energy Technology Data Exchange (ETDEWEB)

    Calasans-Maia, Monica, E-mail: monicacalasansmaia@gmail.com [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Calasans-Maia, José, E-mail: josecalasans@gmail.com [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Santos, Silvia, E-mail: silviaquimica@gmail.com [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Mavropoulos, Elena, E-mail: elena@cbpf.br [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Farina, Marcos, E-mail: mfarina@anato.ufrj.br [Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Lima, Inayá, E-mail: inayacorrea@gmail.com [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Lopes, Ricardo Tadeu [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Rossi, Alexandre, E-mail: rossi@cbpf.br [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Granjeiro, José Mauro, E-mail: jmgranjeiro@gmail.com [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Bioengineering Division, National Institute of Metrology, Quality and Technology, Duque de Caxias, Rio de Janeiro (Brazil)

    2014-08-01

    The effect of zinc-substituted calcium phosphate (CaP) on bone osteogenesis was evaluated using an in vivo normalized ISO 10993-6 protocol. Zinc-containing hydroxyapatite (ZnHA) powder with 0.3% by wt zinc (experimental group) and stoichiometric hydroxyapatite (control group) were shaped into cylindrical implants (2 × 6 mm) and were sintered at 1000 °C. Thermal treatment transformed the ZnHA cylinder into a biphasic implant that was composed of Zn-substituted HA and Zn-substituted β-tricalcium phosphate (ZnHA/βZnTCP); the hydroxyapatite cylinder was a highly crystalline and poorly soluble HA implant. In vivo tests were performed in New Zealand White rabbits by implanting two cylinders of ZnHA/βZnTCP in the left tibia and two cylinders of HA in the right tibia for 7, 14 and 28 days. Incorporation of 0.3% by wt zinc into CaP increased the rate of Zn release to the biological medium. Microfluorescence analyses (μXRF-SR) using synchrotron radiation suggested that some of the Zn released from the biomaterial was incorporated into new bone near the implanted region. In contrast with previous studies, histomorphometric analysis did not show significant differences between the newly formed bone around ZnHA/βZnTCP and HA due to the dissolution profile of Zn-doped CaP. Despite the great potential of Zn-containing CaP matrices for future use in bone regeneration, additional in vivo studies must be conducted to explain the mobility of zinc at the CaP surface and its interactions with a biological medium. - Highlights: • We produced a hydroxyapatite containing a low concentration (0.3 wt.%) of zinc. • The biomaterial underwent characterization before and after in vivo implant. • In vivo tests were performed according to ISO 10993-6. • Zinc-containing calcium phosphate promotes osteoconduction and bone regeneration. • Zinc-containing calcium phosphate may be useful for clinical applications.

  10. Short-term in vivo evaluation of zinc-containing calcium phosphate using a normalized procedure

    International Nuclear Information System (INIS)

    The effect of zinc-substituted calcium phosphate (CaP) on bone osteogenesis was evaluated using an in vivo normalized ISO 10993-6 protocol. Zinc-containing hydroxyapatite (ZnHA) powder with 0.3% by wt zinc (experimental group) and stoichiometric hydroxyapatite (control group) were shaped into cylindrical implants (2 × 6 mm) and were sintered at 1000 °C. Thermal treatment transformed the ZnHA cylinder into a biphasic implant that was composed of Zn-substituted HA and Zn-substituted β-tricalcium phosphate (ZnHA/βZnTCP); the hydroxyapatite cylinder was a highly crystalline and poorly soluble HA implant. In vivo tests were performed in New Zealand White rabbits by implanting two cylinders of ZnHA/βZnTCP in the left tibia and two cylinders of HA in the right tibia for 7, 14 and 28 days. Incorporation of 0.3% by wt zinc into CaP increased the rate of Zn release to the biological medium. Microfluorescence analyses (μXRF-SR) using synchrotron radiation suggested that some of the Zn released from the biomaterial was incorporated into new bone near the implanted region. In contrast with previous studies, histomorphometric analysis did not show significant differences between the newly formed bone around ZnHA/βZnTCP and HA due to the dissolution profile of Zn-doped CaP. Despite the great potential of Zn-containing CaP matrices for future use in bone regeneration, additional in vivo studies must be conducted to explain the mobility of zinc at the CaP surface and its interactions with a biological medium. - Highlights: • We produced a hydroxyapatite containing a low concentration (0.3 wt.%) of zinc. • The biomaterial underwent characterization before and after in vivo implant. • In vivo tests were performed according to ISO 10993-6. • Zinc-containing calcium phosphate promotes osteoconduction and bone regeneration. • Zinc-containing calcium phosphate may be useful for clinical applications

  11. Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones

    International Nuclear Information System (INIS)

    Apatite- and tricalcium phosphate-based materials were produced from codfish bones, thus converting a waste by-product from the food industry into high added-valued compounds. The bones were annealed at temperatures between 900 and 1200 °C, giving a biphasic material of hydroxyapatite and tricalcium phosphate (Ca10(PO4)6(OH)2 and β-Ca(PO4)3) with a molar proportion of 75:25, a material widely used in biomedical implants. The treatment of the bones in solution prior to their annealing changed the composition of the material. Single phase hydroxyapatite, chlorapatite (Ca10(PO4)6Cl2) and fluorapatite (Ca10(PO4)6F2) were obtained using CaCl2 and NaF solutions, respectively. The samples were analysed by several techniques (X-ray diffraction, infrared spectroscopy, scanning electron microscopy and differential thermal/thermogravimetric analysis) and by elemental analyses, to have a more complete understanding of the conversion process. Such compositional modifications have never been performed before for these materials of natural origin to tailor the relative concentrations of elements. This paper shows the great potential for the conversion of this by-product into highly valuable compounds for biomedical applications, using a simple and effective valorisation process. - Highlights: ► Apatite and calcium phosphate compounds extraction from cod fish bonesBone calcination: biphasic material hydroxyapatite-calcium phosphate production ► Bone pre-treatments in solution change the material composition. ► Single phase materials (hydroxy-, chloro- or fluoroapatite) are obtained. ► Concentration of other elements (Na, F, Cl) suitable for biomedical applications

  12. Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones

    Energy Technology Data Exchange (ETDEWEB)

    Piccirillo, C.; Silva, M.F. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pullar, R.C. [Dept. Engenharia de Materiais e Ceramica/CICECO, Universidade de Aveiro, Aveiro (Portugal); Braga da Cruz, I. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Jorge, R. [WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pintado, M.M.E. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Castro, P.M.L., E-mail: plcastro@porto.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal)

    2013-01-01

    Apatite- and tricalcium phosphate-based materials were produced from codfish bones, thus converting a waste by-product from the food industry into high added-valued compounds. The bones were annealed at temperatures between 900 and 1200 Degree-Sign C, giving a biphasic material of hydroxyapatite and tricalcium phosphate (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and {beta}-Ca(PO{sub 4}){sub 3}) with a molar proportion of 75:25, a material widely used in biomedical implants. The treatment of the bones in solution prior to their annealing changed the composition of the material. Single phase hydroxyapatite, chlorapatite (Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}) and fluorapatite (Ca{sub 10}(PO{sub 4}){sub 6}F{sub 2}) were obtained using CaCl{sub 2} and NaF solutions, respectively. The samples were analysed by several techniques (X-ray diffraction, infrared spectroscopy, scanning electron microscopy and differential thermal/thermogravimetric analysis) and by elemental analyses, to have a more complete understanding of the conversion process. Such compositional modifications have never been performed before for these materials of natural origin to tailor the relative concentrations of elements. This paper shows the great potential for the conversion of this by-product into highly valuable compounds for biomedical applications, using a simple and effective valorisation process. - Highlights: Black-Right-Pointing-Pointer Apatite and calcium phosphate compounds extraction from cod fish bones Black-Right-Pointing-Pointer Bone calcination: biphasic material hydroxyapatite-calcium phosphate production Black-Right-Pointing-Pointer Bone pre-treatments in solution change the material composition. Black-Right-Pointing-Pointer Single phase materials (hydroxy-, chloro- or fluoroapatite) are obtained. Black-Right-Pointing-Pointer Concentration of other elements (Na, F, Cl) suitable for biomedical applications.

  13. Calcium salts of keto-amino acids, a phosphate binder alternative for patients on CAPD.

    Science.gov (United States)

    Macia, M; Coronel, F; Navarro, J F; Gallego, E; Herrero, J A; Méndez, M L; Chahin, J; García, J

    1997-09-01

    Control of hyperphosphoremia is crucial to the prevention of secondary hyperparathyroidism. Calcium salts of keto-amino acids (KAA) were employed as phosphate binders in hemodialysis patients. We wanted to assess the efficacy of these substances as quelating agents in patients under continuous ambulatory peritoneal dialysis (CAPD). Also, as an amino acid supplement, we determined their possible effect on some parameters related to nutritional status. We studied 13 patients (7 M; 6 F) with a mean age of 45.2 +/- 17 years and a mean time on CAPD of 18.4 +/- 11.4 months. None had severe secondary hyperparathyroidism and/or clinically relevant aluminium intoxication. They were not receiving calcitriol and none were using low-calcium peritoneal dialysis fluids. All were under aluminum hydroxide (AlOH3) treatment and 8 patients also received calcium carbonate. These quelating agents were withdrawn and after 21 days (wash-out period) KAA were initiated. We analyzed serum levels of bone metabolism parameters (calcium, phosphate, osteocalcin [OC], intact parathyroid hormone [iPTH], alkaline phosphatase [AP]) and nutritional parameters (total protein, albumin, pre-albumin, transferrin) in four periods: (A) during AlOH3; (B) immediately after the washout period; (C) after 1.5 months; and (D) after 3 months of KAA therapy. In 5 patients serum aluminum level was also measured in periods (A) and (D). The serum phosphate level at period (B) was significantly higher than in other periods. After 3 months of treatment phosphate levels decreased significantly (A = 1.77 +/- 0.3 mmol/l vs D = 1.48 +/- 0.2; p < 0.05). Serum calcium levels increased, while iPTH and OC decreased (p = ns). AP remained stable during the study. All nutritional parameters increased at the end of the study (p = ns). Calcium salts of keto-amino acids showed to be an effective alternative to aluminum-containing phosphate binders. They were well tolerated, without relevant side-effects. These compounds could also

  14. A Comprehensive Study of Osteogenic Calcium Phosphate Silicate Cement: Material Characterization and In Vitro/In Vivo Testing.

    Science.gov (United States)

    Gong, Tianxing; Wang, Zhiqin; Zhang, Yixi; Zhang, Yubiao; Hou, Mingxiao; Liu, Xinwei; Wang, Yu; Zhao, Lejun; Ruse, N Dorin; Troczynski, Tom; Häfeli, Urs O

    2016-02-18

    Vertebral compression fractures can be successfully restored by injectable bone cements. Here the as-yet unexplored in vitro cytotoxicity, in vivo biodegradation, and osteoconductivity of a new calcium phosphate silicate cements (CPSC) are studied, where monocalcium phosphate (MCP; 5, 10, and 15 wt%) is added to calcium silicate cement (CSC). Setting rate and compressive strength of CPSC decrease with the addition of MCP. The crystallinity, microstructure, and porosity of hardened CPSC are evaluated by X-ray diffractometer, Fourier transform infrared spectroscopy, and microcomputed tomography (CT). It is found that MCP reacts with calcium hydroxide, one of CSC hydration products, to precipitate apatite. While the reaction accelerates the hydration of CSC, the formation of calcium silicate hydrate gel is disturbed and highly porous microstructures form, resulting in weaker compressive strength. In vitro studies demonstrate that CPSC is noncytotoxic to osteoblast cells and promotes their proliferation. In the rabbit tibia implantation model, clinical X-ray and CT scans demonstrate that CPSC biodegrades slower and osseointegrates better than clinically used calcium phosphate cement (CPC). Histological studies demonstrate that CPSC is osteoconductive and induces higher bone formation than CPC, a finding that might warrant future clinical studies. PMID:26677175

  15. Calcium-phosphate-osteopontin particles for caries control.

    Science.gov (United States)

    Schlafer, Sebastian; Birkedal, Henrik; Olsen, Jakob; Skovgaard, Jonas; Sutherland, Duncan S; Wejse, Peter L; Nyvad, Bente; Meyer, Rikke L

    2016-01-01

    Caries is caused by acid production in biofilms on dental surfaces. Preventing caries therefore involves control of microorganisms and/or the acid produced. Here, calcium-phosphate-osteopontin particles are presented as a new approach to caries control. The particles are made by co-precipitation and designed to bind to bacteria in biofilms, impede biofilm build-up without killing the microflora, and release phosphate ions to buffer bacterial acid production if the pH decreases below 6. Analysis of biofilm formation and pH in a five-species biofilm model for dental caries showed that treatment with particles or pure osteopontin led to less biofilm formation compared to untreated controls or biofilms treated with osteopontin-free particles. The anti-biofilm effect can thus be ascribed to osteopontin. The particles also led to a slower acidification of the biofilm after exposure to glucose, and the pH always remained above 5.5. Hence, calcium-phosphate-osteopontin particles show potential for applications in caries control. PMID:26923119

  16. Calcium Regulation and Bone Mineral Metabolism in Elderly Patients with Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Vickram Tejwani

    2013-05-01

    Full Text Available The elderly chronic kidney disease (CKD population is growing. Both aging and CKD can disrupt calcium (Ca2+ homeostasis and cause alterations of multiple Ca2+-regulatory mechanisms, including parathyroid hormone, vitamin D, fibroblast growth factor-23/Klotho, calcium-sensing receptor and Ca2+-phosphate product. These alterations can be deleterious to bone mineral metabolism and soft tissue health, leading to metabolic bone disease and vascular calcification and aging, termed CKD-mineral and bone disorder (MBD. CKD-MBD is associated with morbid clinical outcomes, including fracture, cardiovascular events and all-cause mortality. In this paper, we comprehensively review Ca2+ regulation and bone mineral metabolism, with a special emphasis on elderly CKD patients. We also present the current treatment-guidelines and management options for CKD-MBD.

  17. Europium-doped amorphous calcium phosphate porous nanospheres: preparation and application as luminescent drug carriers

    OpenAIRE

    Zhang Kui-Hua; Mo Xiu-Mei; Chen Feng; Zhu Ying-Jie; Wu Jin; Wang Ke-Wei; Tang Qi-Li

    2011-01-01

    Abstract Calcium phosphate is the most important inorganic constituent of biological tissues, and synthetic calcium phosphate has been widely used as biomaterials. In this study, a facile method has been developed for the fabrication of amorphous calcium phosphate (ACP)/polylactide-block-monomethoxy(polyethyleneglycol) hybrid nanoparticles and ACP porous nanospheres. Europium-doping is performed to enable photoluminescence (PL) function of ACP porous nanospheres. A high specific surface area ...

  18. Effect of polydopamine on the biomimetic mineralization of mussel-inspired calcium phosphate cement in vitro

    International Nuclear Information System (INIS)

    Inspired by the excellent adhesive property of mussel adhesive protein, we added polydopamine (PDA) to calcium phosphate cement (PDA–CPC) to enhance its compressive strength previously. The mineralization and mechanism on PDA–CPC were investigated by soaking it in simulated body fluid in this study. The results indicated that PDA promoted the conversion of dicalcium phosphate dihydrate and α-tricalcium phosphate to hydroxyapatite (HA) in the early stage but inhibited this conversion subsequently. PDA promoted the rapid mineralization on PDA–CPC to form a layer of nanoscale calcium phosphate (CaP) whereas there was no CaP formation on the control-CPC after 1 d of soaking. This layer of nanoscale CaP was similar to that of natural bone, which was always observed during soaking. X-ray photoelectron spectroscopy showed that the peak of C=O of PDA existed in the newly formed CaP on PDA–CPC, indicating the co-precipitation of CaP with PDA. Furthermore, the newly formed CaP on PDA–CPC was HA confirmed by transmission electron microscopy, which the newly formed HA was in association with PDA. Therefore, PDA increased the capacity of mineralization of CPC and induced the formation of nanoscale bone-like apatite on PDA–CPC. Thus, this provides the feasible route for surface modification on CPC. - Highlights: • Effect of polydopamine (PDA) on the in vitro mineralization of PDA-CPC was studied. • PDA promoted the rapid mineralization on PDA-CPC to form a nanoscale HA layer. • The precipitation of the nanoscale HA layer on PDA-CPC accompanied with PDA. • Polydopamine induced mineralization is feasible for surface modification of CaP

  19. Effect of polydopamine on the biomimetic mineralization of mussel-inspired calcium phosphate cement in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zongguang [Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Qu, Shuxin, E-mail: qushuxin@swjtu.edu.cn [Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Zheng, Xiaotong; Xiong, Xiong [Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Fu, Rong; Tang, Kuangyun; Zhong, Zhendong [Department of Plastic Surgery, Academy of Medical Sciences and Sichuan Provincial People' s Hospital, Chengdu 610041 (China); Weng, Jie [Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

    2014-11-01

    Inspired by the excellent adhesive property of mussel adhesive protein, we added polydopamine (PDA) to calcium phosphate cement (PDA–CPC) to enhance its compressive strength previously. The mineralization and mechanism on PDA–CPC were investigated by soaking it in simulated body fluid in this study. The results indicated that PDA promoted the conversion of dicalcium phosphate dihydrate and α-tricalcium phosphate to hydroxyapatite (HA) in the early stage but inhibited this conversion subsequently. PDA promoted the rapid mineralization on PDA–CPC to form a layer of nanoscale calcium phosphate (CaP) whereas there was no CaP formation on the control-CPC after 1 d of soaking. This layer of nanoscale CaP was similar to that of natural bone, which was always observed during soaking. X-ray photoelectron spectroscopy showed that the peak of C=O of PDA existed in the newly formed CaP on PDA–CPC, indicating the co-precipitation of CaP with PDA. Furthermore, the newly formed CaP on PDA–CPC was HA confirmed by transmission electron microscopy, which the newly formed HA was in association with PDA. Therefore, PDA increased the capacity of mineralization of CPC and induced the formation of nanoscale bone-like apatite on PDA–CPC. Thus, this provides the feasible route for surface modification on CPC. - Highlights: • Effect of polydopamine (PDA) on the in vitro mineralization of PDA-CPC was studied. • PDA promoted the rapid mineralization on PDA-CPC to form a nanoscale HA layer. • The precipitation of the nanoscale HA layer on PDA-CPC accompanied with PDA. • Polydopamine induced mineralization is feasible for surface modification of CaP.

  20. Drugs Used in Paediatric Bone and Calcium Disorders.

    Science.gov (United States)

    Cheung, Moira S

    2015-01-01

    Calcium and bone disorders in children and adolescents are treated with a wide variety of drugs. Several of these drugs have been used for many years on the basis of accepted practice, without being subjected to rigorous trials. Bisphosphonates are the mainstay treatment for children with osteoporosis, but newer, more potent compounds such as zoledronate and risedronate have begun to replace the older-generation bisphosphonates. Hypocalcaemia is managed with calcium and vitamin D and its metabolites. In difficult cases that are secondary to hypoparathyroidism, subcutaneous injections or infusions of parathyroid hormone have been used. Multiple daily phosphate supplements and calcitriol are the standard treatment for hypophosphataemic rickets, but trials of an anti-fibroblast growth factor 23 antibody appear promising, and the results are eagerly awaited. Many new medications are undergoing clinical trials and are starting to emerge as viable treatment options for children. Some of these drugs target specific diseases, such as recombinant alkaline phosphatase for hypophosphatasia and a C-type natriuretic peptide analogue for achondroplasia. Other drugs, such as denosumab and odanacatib, have been used successfully in the adult population, and the appropriate use of these drugs in children is now being evaluated. PMID:26138848

  1. A histological evaluation on osteogenesis and resorption of methotrexate-loaded calcium phosphate cement in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Li Dong; Yang Zhiping; Li Xin; Li Zhenfeng; Li Jianmin [Department of Orthopedics, Qilu Hospital of Shandong University, Shandong (China); Yang Jingyan, E-mail: yangzhiping@medmail.com.c [Department of Pathology, 2nd Affiliated Hospital of Shandong University, Shandong (China)

    2010-04-15

    In this study, we investigated the resorption of in vivo methotrexate-loaded calcium phosphate cement (MTX-CPC) implants and their effect on osteogenesis. MTX-CPC implants containing 1% methotrexate (MTX) (weight/weight) were preset and implanted into the femoral condyle of rabbits. Calcium phosphate cement (CPC) without MTX was used as the control. The femurs were harvested at day 1 and at 1, 3 and 6 months after implantation and radiological examination were performed. Decalcified sections were examined by hematoxylin and eosin (HE) staining, alkaline phosphatase (ALPase) immunohistochemistry and tartrate-resistant acid phosphatase (TRAPase) enzyme histochemistry. Then, we performed histomorphometric analysis, including determination of the percentage of newly formed bone and osteoblast and osteoclast counts. The results indicated that MTX-CPC implants were biocompatible, biodegradable and osteoconducive. However, MTX release from the implantation site inhibited osteogenesis in the initial period; this inhibition weakened with time, and no difference was observed between CPC and MTX-CPC at 6 months after implantation. Hence, MTX-CPC is an excellent material for filling defects and can be used for preparing effective drug delivery systems to achieve local control of invasive bone tumors.

  2. A histological evaluation on osteogenesis and resorption of methotrexate-loaded calcium phosphate cement in vivo

    International Nuclear Information System (INIS)

    In this study, we investigated the resorption of in vivo methotrexate-loaded calcium phosphate cement (MTX-CPC) implants and their effect on osteogenesis. MTX-CPC implants containing 1% methotrexate (MTX) (weight/weight) were preset and implanted into the femoral condyle of rabbits. Calcium phosphate cement (CPC) without MTX was used as the control. The femurs were harvested at day 1 and at 1, 3 and 6 months after implantation and radiological examination were performed. Decalcified sections were examined by hematoxylin and eosin (HE) staining, alkaline phosphatase (ALPase) immunohistochemistry and tartrate-resistant acid phosphatase (TRAPase) enzyme histochemistry. Then, we performed histomorphometric analysis, including determination of the percentage of newly formed bone and osteoblast and osteoclast counts. The results indicated that MTX-CPC implants were biocompatible, biodegradable and osteoconducive. However, MTX release from the implantation site inhibited osteogenesis in the initial period; this inhibition weakened with time, and no difference was observed between CPC and MTX-CPC at 6 months after implantation. Hence, MTX-CPC is an excellent material for filling defects and can be used for preparing effective drug delivery systems to achieve local control of invasive bone tumors.

  3. An ultrasonic through-transmission technique for monitoring the setting of injectable calcium phosphate cement.

    Science.gov (United States)

    Rajzer, Izabella; Piekarczyk, Wojciech; Castaño, Oscar

    2016-10-01

    An ultrasound through-transmission method to monitor the setting process of injectable calcium phosphate bone cements in body fluids is presented. This method can be used to determine the acoustic properties of the bone cement as it sets, which are linked to its material properties and provide some information about changes occurring within the cement. The development of the methodology of ultrasonic testing and execution of velocity measurements of the longitudinal and transverse waves using the through-transmission method made it possible to determine the material constants of samples during the setting and hardening process of an injectable cement paste in physiological fluids (i.e. the Young's modulus (E), the Poisson ratio (ν) and the shear modulus (G)), and to determine the degree of anisotropy of wave velocity in the samples. A strong advantage of the proposed method is that it is non-destructive, and the same sample can be used to monitor the whole process of the cement setting. The testing was performed on premixed and injectable calcium phosphate (CPC)/chitosan blend, where glycerol was used as a liquid phase. Comparisons between ultrasonic velocity and empirical tests such as compressive strength, porosity measurement, FTIR, SEM and XRD analysis at different days of immersion in Ringer's solutions showed that the ultrasonic velocity can be very useful to provide in situ information about changes occurring within the cement. PMID:27287094

  4. Importance of FTIR Spectra Deconvolution for the Analysis of Amorphous Calcium Phosphates

    Science.gov (United States)

    Brangule, Agnese; Agris Gross, Karlis

    2015-03-01

    This work will consider Fourier transform infrared spectroscopy - diffuse reflectance infrared reflection (FTIR-DRIFT) for collecting the spectra and deconvolution to identify changes in bonding as a means of more powerful detection. Spectra were recorded from amorphous calcium phosphate synthesized by wet precipitation, and from bone. FTIR-DRIFT was used to study the chemical environments of PO4, CO3 and amide. Deconvolution of spectra separated overlapping bands in the ʋ4PO4, ʋ2CO3, ʋ3CO3 and amide region allowing a more detailed analysis of changes at the atomic level. Amorphous calcium phosphate dried at 80 oC, despite showing an X-ray diffraction amorphous structure, displayed carbonate in positions resembling a carbonated hydroxyapatite. Additional peaks were designated as A1 type, A2 type or B type. Deconvolution allowed the separation of CO3 positions in bone from amide peaks. FTIR-DRIFT spectrometry in combination with deconvolution offers an advanced tool for qualitative and quantitative determination of CO3, PO4 and HPO4 and shows promise to measure the degree of order.

  5. Investigation of duty cycle effect on corrosion properties of electrodeposited calcium phosphate coatings.

    Science.gov (United States)

    Azem, Funda Ak; Delice, Tulay Koc; Ungan, Guler; Cakir, Ahmet

    2016-11-01

    The bioceramic calcium phosphate (CaP) is frequently used for improving bone fixation in titanium medical implants and thus increasing lifetime of the implant. It is known that the application of CaP coatings on metallic implant devices offers the possibility of combining the strength of the metals and the bioactivity of the ceramic materials. Many different techniques are available for producing CaP coatings. Electrochemical deposition method is widely used because of its ease of operation parameters, low temperature requirement, reproducibility and suitability for coating complex structures. This technique allows obtaining CaP coatings which promote bone in growth during the first healing period leading to permanent fixation. Electrochemical pulse technique is an alternative to calcium phosphate deposition techniques usually employed to cover orthopedic or dental titanium implant surfaces. Additionally, pulse electrodeposition technique can produce more uniform and denser CaP coatings on metallic implants. In this study, CaP based coatings were produced by electrochemical pulse technique on Ti6Al4V substrates. The resulting CaP deposits were investigated by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Corrosion properties of the CaP coatings were also investigated. The results showed that various duty cycle ranges have remarkably effect on morphology, crystallinity and corrosion properties of the produced CaP coatings. PMID:27524068

  6. Biomimetic calcium phosphate coating on Ti-7.5Mo alloy for dental application.

    Science.gov (United States)

    Escada, A L A; Machado, J P B; Schneider, S G; Rezende, M C R Alves; Claro, A P R Alves

    2011-11-01

    Titanium and its alloys have been used as bone-replacement implants due to their excellent corrosion resistance and biocompatibility. However, a titanium coating is a bioinert material and cannot bond chemically to bone tissue. The objective of this work was to evaluate the influence of alkaline treatment and heat treatment on the formation of calcium phosphate layer on the surface of a Ti-7.5Mo alloy after soaking in simulated body fluid (SBF). Thirty six titanium alloy plates were assigned into two groups. For group I, samples were immersed in a 5.0-M NaOH aqueous solution at 80°C for 72 h, washed with distilled water and dried at 40°C for 24 h. For group II, after the alkaline treatment, samples were heat-treated at 600°C for 1 h in an electrical furnace in air. Then, all samples were immersed in SBF for 7 or 14 days to allow the formation of a calcium phosphate coating on the surface. The surfaces were characterized using SEM, EDS, AFM and contact angle measurements.

  7. The effects of calcium phosphate particles on the growth of osteoblasts.

    Science.gov (United States)

    Sun, J S; Tsuang, Y H; Liao, C J; Liu, H C; Hang, Y S; Lin, F H

    1997-12-01

    With advances in ceramics technology, calcium phosphate bioceramics have been applied as bone substitutes for several decades. The focus of this work is to elucidate the biocompatibility of the particulates of various calcium phosphate cytotoxicities. Four different kinds of calcium phosphate powders, including beta-tricalcium phosphate (beta-TCP), hydroxyapatite (HA), beta-dicalcium pyrophosphate (beta-DCP), and sintered beta-dicalcium pyrophosphate (SDCP), were tested by osteoblast cell culture. The results were analyzed by cell count, concentration of transforming growth factor-beta 1 (TGF-beta 1), alkaline phosphatase (ALP), and prostaglandin E2 (PGE2) in culture media. The changes were most significant when osteoblasts were cultured with beta-TCP and HA bioceramics. The changes in cell population of the beta-TCP and HA were quite low in the first 3 days, then increased gradually toward the seventh day. The changes in TGF-beta 1 concentration in culture medium inversely related to the changes in cell population. The ALP titer in the culture media of the beta-TCP and HA were quite high in the first 3 days, then decreased rapidly between the third and seventh days. The concentrations of PGE2 in the culture media tested were quite high on the first day, decreased rapidly to the third day, and then gradually until the seventh day. The changes in the beta-DCP and SDCP were quite similar to those of HA and beta-TCP but much less significant. We conclude that HA and beta-TCP have an inhibitory effect on the growth of osteoblasts. The inhibitins effects of the HA and beta-TCP powders on the osteoblast cell cultures possibly are mediated by the increased synthesis of PGE2.

  8. A new evaporation-based method for the preparation of biomimetic calcium phosphate coatings on metals

    International Nuclear Information System (INIS)

    This study reports a new method to prepare biomimetic calcium phosphate coatings on titanium, stainless steel, CoCrMo, and tantalum. The method does not require surface etching, high supersaturation, or tight control of solution conditions. Metallic samples were dipped into a supersaturated calcium phosphate solution, withdrawn, and left to dry at room temperature. Calcium phosphate crystallites formed on and completely covered the surfaces by repeating the dip-and-dry treatment. The crystallite-covered surfaces readily grew to calcium phosphate coatings when immersed in the supersaturated solution. The mechanism of the treatment was suggested to be an evaporation-induced surface crystallization process.

  9. Biological value of bone-precipitated dicalcium phosphate in turkey starter diets.

    Science.gov (United States)

    Sullivan, T W; Douglas, J H; Lapjatupon, W; Struwe, F J; Gonzalez, N J

    1994-01-01

    A study was conducted to determine the relative biological value (RBV) of phosphorus from two bone-precipitated dicalcium phosphates (DCP-BP) in turkey starter diets. An estimated 40,000 metric tons of DCP-BP are produced annually in the United States as a by-product of gelatin production. The two DCP-BP sources were compared to commercial feed phosphates. Two bioassay experiments of 21-d duration were conducted with female turkeys. Phosphate sources were each fed at three levels (.18, .24, and .36% added total phosphorus) in a corn-soybean meal diet. Calcium level was maintained constant at 1.0% in all diets by adjusting the level of ground limestone. Four replicate pens of six poults were randomly assigned at 1 d of age to each level of each phosphorus source in each bioassay. The reference standard was United States Pharmacopeia (USP) grade calcium phosphate, dibasic dihydrate. Data representing three response criteria (weight gain, gain:feed ratio, and tibia ash percentage at 21 d) were combined to calculate a biological value (BV) for each test source and the reference standard phosphate. A RBV was then computed for each test source. The RBV of the two DCP-BP sources were 98.8 and 99.1, as compared to 100.0 for the reference standard, and 86.7, 87.1, and 88.4 for three commercial, thermochemically produced defluorinated phosphates. The RBV of one commercial mono-dicalcium phosphate, and three di-monocalcium phosphates were: 96.4, and 91.2, 94.7, and 101.5, respectively. The two DCP-BP sources compared favorably to commercial feed phosphates, and would be satisfactory supplements in diets for starting chicks, poults, pigs, and other species.

  10. Combination of simvastatin, calcium silicate/gypsum, and gelatin and bone regeneration in rabbit calvarial defects

    OpenAIRE

    Jing Zhang; Huiming Wang; Jue Shi; Ying Wang; Kaichen Lai; Xianyan Yang; Xiaoyi Chen; Guoli Yang

    2016-01-01

    The present study was performed to determine whether simvastatin improves bone regeneration when combined with calcium silicate/gypsum and gelatin (CS-GEL). The surface morphology was determined using field-emission scanning electron microscopy (FSEM). Degradation in vitro was evaluated by monitoring the weight change of the composites soaked in phosphate buffered saline (PBS). Drug release was evaluated using high-performance liquid chromatography (HPLC). Cytotoxicity testing was performed t...

  11. Nanocrystalline biphasic resorbable calcium phosphate (HAp/β-TCP) thin film prepared by electron beam evaporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Elayaraja, K.; Chandra, V. Sarath; Joshy, M.I. Ahymah; Suganthi, R.V. [Crystal Growth Centre, Anna University, Chennai 600025, Tamil Nadu (India); Asokan, K. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Kalkura, S. Narayana, E-mail: kalkura@yahoo.com [Crystal Growth Centre, Anna University, Chennai 600025, Tamil Nadu (India)

    2013-06-01

    Biphasic calcium phosphate (BCP) thin film having resorbable β-tricalcium phosphate (β-TCP) and non-resorbable hydroxyapatite (HAp) phases having enhanced bioactivity was synthesized by electron beam evaporation technique. Nanosized BCP was deposited as a layer (500 nm) on (0 0 1) silicon substrate by electron beam evaporation and crystalline phase of samples were found to improve on annealing at 700 °C. Uniform deposition of calcium phosphate on silicon substrate was verified from elemental mapping using scanning electron microscope (SEM-EDX). Annealing of the samples led to a decrease in surface roughness, hydrophobicity and dissolution of the coating layer. Amoxicillin loaded thin films exhibited significant bacterial resistance. In addition, BCP thin films did not exhibit any cytotoxicity. Antibiotics incorporated BCP coated implants might prevent the post-surgical infections and could promote bone-bonding of orthopedic devices.

  12. Modifications on the properties of a calcium phosphate cement by additions of sodium alginate

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, W.T.; Fernandes, J.M.; Vieira, R.S.; Thurmer, M.B.; Santos, L.A., E-mail: trajano@ufrgs.br, E-mail: julianafernandes2@yahoo.com.br, E-mail: rsvieira.eng@gmail.com, E-mail: monicathurmer@yahoo.com.br, E-mail: luis.santos@ufrgs.br [Universidade Federal do Rio Grande do Sul (PPG/LABIOMAT/UFRGS), RS (Brazil)

    2012-07-01

    The Calcium Phosphate Cement (CPC) are bone substitutes with great potential for use in orthopedics, traumatology and dentistry due to its biocompatibility, bioactivity and osteoconductivity, and form a paste that can be easily shaped and placed into the surgical site. However, CPCs have low mechanical strength, which equals the maximum mechanical strength of trabecular bone. In order to assess the strength and time to handle a CPC composed primarily of alpha phase, were added sodium alginate (1%, 2% and 3% wt) and an accelerator in an aqueous solution. The cement powder was mixed with liquid of setting, shaped into specimens and evaluated for apparent density and porosity by Archimedes method, X-ray diffraction and compressive strength. A significant increase in compressive strength by adding sodium alginate was verified. (author)

  13. Modifications on the properties of a calcium phosphate cement by additions of sodium alginate

    International Nuclear Information System (INIS)

    The Calcium Phosphate Cement (CPC) are bone substitutes with great potential for use in orthopedics, traumatology and dentistry due to its biocompatibility, bioactivity and osteoconductivity, and form a paste that can be easily shaped and placed into the surgical site. However, CPCs have low mechanical strength, which equals the maximum mechanical strength of trabecular bone. In order to assess the strength and time to handle a CPC composed primarily of alpha phase, were added sodium alginate (1%, 2% and 3% wt) and an accelerator in an aqueous solution. The cement powder was mixed with liquid of setting, shaped into specimens and evaluated for apparent density and porosity by Archimedes method, X-ray diffraction and compressive strength. A significant increase in compressive strength by adding sodium alginate was verified. (author)

  14. Low-pressure plasma treatment of polylactide fibers for enhanced mechanical performance of fiber-reinforced calcium phosphate cements

    OpenAIRE

    Canal Barnils, Cristina; Gallinetti, Sara; Ginebra Molins, Maria Pau

    2014-01-01

    Calcium phosphate cements (CPCs) are extensively used as synthetic bone grafts, but their poor mechanical properties limit their applicability to non-stress-bearing applications. The aim of the present work is to evaluate the potential of plasma surface modification of polylactide (PLA) fibers for reinforcement of CPCs. Oxygen low-pressure plasma was employed at different treatment times and the surface properties of the untreated and plasma-treated PLA were evaluated. Plasma treatment on the...

  15. 重组人类骨形态蛋白2复合自固化磷酸钙材料在体内的血管化%Vascularization of autosetting calcium phosphate cultivated with recombinant human bone morphogenetic protein 2

    Institute of Scientific and Technical Information of China (English)

    王炜; 玛依拉·吾甫尔; 阿不都赛米·艾买提; 艾合买提江·玉素甫

    2011-01-01

    BACKGROUND: Deep fascia promotes vascularization of tissue-engineered bone, which is a mature technology, but different animal species and different implant materials can result in a great difference in vascularization.OBJECTIVE: To compare the vascularization of autosetting calcium phosphate cement cultivated with recombinant human bone morphogenetic protein 2 (rhBMP-2) and a single autosetting calcium phosphate cement implant in beagle dogs with deep fasica flaps. METHODS: Twelve healthy adult beagle dogs were respectively implanted with autosetting calcium phosphate cement cultivated with rhBMP-2 in the left thigh (experimental sides) and a single autosetting calcium phosphate cement in right thigh (control sides). The vascularization in each condition was assessed by experiment study (Physical, Massion stain, the hematoxylin-eosin stain, ⅧRAg marked) at time intervals of 2, 4, 8 and 16 weeks after operation.RESULTS AND CONCLUSION: In experimental groups and in control groups, vascularization was found. New vessels invaded in scaffold with time. In experimental groups, the amount of vessels and the expression of ⅧRAg were stronger than those in control groups at 2, 4, 8, and 16 weeks. The deep fasica flaps have great effect on the vascularization. The deep fasica flap binding with rhBMP-2 is proved to be the better in vascularization of autosetting calcium phosphate cement.%背景:深筋膜瓣促进组织工程骨血管化是一种成熟的技术,但动物种属不同、植入材料不同均会使血管化的结果产生较大的差异.目的:比较复合重组人类骨形态蛋白2的自固化磷酸钙人工骨和单纯的自固化磷酸钙人工骨在比格犬带蒂筋膜瓣内的血管再生能力.方法:分别将复合重组人骨形态蛋白2的自固化磷酸钙人工骨和单纯的自固化磷酸钙人工骨包裹于12只成年比格犬腰背部两侧带蒂深筋膜瓣中,于术后第2,4,8,16周各随机选取3只动物摘取血管化标本,进行大

  16. A New Type of Biphasic Calcium Phosphate Cement as a Gentamicin Carrier for Osteomyelitis

    Directory of Open Access Journals (Sweden)

    Wen-Yu Su

    2013-01-01

    Full Text Available Osteomyelitis therapy is a long-term and inconvenient procedure for a patient. Antibiotic-loaded bone cements are both a complementary and alternative treatment option to intravenous antibiotic therapy for the treatment of osteomyelitis. In the current study, the biphasic calcium phosphate cement (CPC, called α-TCP/HAP (α-tricalcium phosphate/hydroxyapatite biphasic cement, was prepared as an antibiotics carrier for osteomyelitis. The developed biphasic cement with a microstructure of α-TCP surrounding the HAP has a fast setting time which will fulfill the clinical demand. The X-ray diffraction and Fourier transform infrared spectrometry analyses showed the final phase to be HAP, the basic bone mineral, after setting for a period of time. Scanning electron microscopy revealed a porous structure with particle sizes of a few micrometers. The addition of gentamicin in α-TCP/HAP would delay the transition of α-TCP but would not change the final-phase HAP. The gentamicin-loaded α-TCP/HAP supplies high doses of the antibiotic during the initial 24 hours when they are soaked in phosphate buffer solution (PBS. Thereafter, a slower drug release is produced, supplying minimum inhibitory concentration until the end of the experiment (30 days. Studies of growth inhibition of Staphylococcus aureus and Pseudomonas aeruginosa in culture indicated that gentamicin released after 30 days from α-TCP/HAP biphasic cement retained antibacterial activity.

  17. Nucleation, growth and evolution of calcium phosphate films on calcite.

    Science.gov (United States)

    Naidu, Sonia; Scherer, George W

    2014-12-01

    Marble, a stone composed of the mineral calcite, is subject to chemically induced weathering in nature due to its relatively high dissolution rate in acid rain. To protect monuments and sculpture from corrosion, we are investigating the application of thin layers of hydroxyapatite (HAP) onto marble. The motivation for using HAP is its low dissolution rate and crystal and lattice compatibility with calcite. A mild, wet chemical synthesis route, in which diammonium hydrogen phosphate salt was reacted with marble, alone and with cationic and anionic precursors under different reaction conditions, was used to produce inorganic HAP layers on marble. Nucleation and growth on the calcite substrate was studied, as well as metastable phase evolution, using scanning electron microscopy, grazing incidence X-ray diffraction, and atomic force microscopy. Film nucleation was enhanced by surface roughness. The rate of nucleation and the growth rate of the film increased with cationic (calcium) and anionic (carbonate) precursor additions. Calcium additions also influenced phase formation, introducing a metastable phase (octacalcium phosphate) and a different phase evolution sequence. PMID:25233226

  18. Calcium phosphate/microgel composites for 3D powderbed printing of ceramic materials.

    Science.gov (United States)

    Birkholz, Mandy-Nicole; Agrawal, Garima; Bergmann, Christian; Schröder, Ricarda; Lechner, Sebastian J; Pich, Andrij; Fischer, Horst

    2016-06-01

    Composites of microgels and calcium phosphates are promising as drug delivery systems and basic components for bone substitute implants. In this study, we synthesized novel composite materials consisting of pure β-tricalcium phosphate and stimuli-responsive poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-vinylimidazole) microgels. The chemical composition, thermal properties and morphology for obtained composites were extensively characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, IGAsorp moisture sorption analyzer, thermogravimetric analysis, granulometric analysis, ESEM, energy dispersive X-ray spectroscopy and TEM. Mechanical properties of the composites were evaluated by ball-on-three-balls test to determine the biaxial strength. Furthermore, initial 3D powderbed-based printing tests were conducted with spray-dried composites and diluted 2-propanol as a binder to evaluate a new binding concept for β-tricalcium phosphate-based granulates. The printed ceramic bodies were characterized before and after a sintering step by ESEM. The hypothesis that the microgels act as polymer adhesive agents by efficient chemical interactions with the β-tricalcium phosphate particles was confirmed. The obtained composites can be used for the development of new scaffolds. PMID:25870955

  19. Calcium phosphate/microgel composites for 3D powderbed printing of ceramic materials.

    Science.gov (United States)

    Birkholz, Mandy-Nicole; Agrawal, Garima; Bergmann, Christian; Schröder, Ricarda; Lechner, Sebastian J; Pich, Andrij; Fischer, Horst

    2016-06-01

    Composites of microgels and calcium phosphates are promising as drug delivery systems and basic components for bone substitute implants. In this study, we synthesized novel composite materials consisting of pure β-tricalcium phosphate and stimuli-responsive poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-vinylimidazole) microgels. The chemical composition, thermal properties and morphology for obtained composites were extensively characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, IGAsorp moisture sorption analyzer, thermogravimetric analysis, granulometric analysis, ESEM, energy dispersive X-ray spectroscopy and TEM. Mechanical properties of the composites were evaluated by ball-on-three-balls test to determine the biaxial strength. Furthermore, initial 3D powderbed-based printing tests were conducted with spray-dried composites and diluted 2-propanol as a binder to evaluate a new binding concept for β-tricalcium phosphate-based granulates. The printed ceramic bodies were characterized before and after a sintering step by ESEM. The hypothesis that the microgels act as polymer adhesive agents by efficient chemical interactions with the β-tricalcium phosphate particles was confirmed. The obtained composites can be used for the development of new scaffolds.

  20. The increasing of enamel calcium level after casein phosphopeptideamorphous calcium phosphate covering

    Directory of Open Access Journals (Sweden)

    Widyasri Prananingrum

    2012-06-01

    Full Text Available Background: Caries process is characterized by the presence of demineralization. Demineralization is caused by organic acids as a result of carbohydrate substrate fermentation. Remineralization is a natural repair process for non-cavitated lesions. Remineralization occurs if there are Ca2+ and PO43- ions in sufficient quantities. Casein-amorphous calcium phosphate phosphopeptide (CPP-ACP is a paste material containing milk protein (casein, that actually contains minerals, such as calcium and phosphate. The casein ability to stabilize calcium phosphate and enhance mineral solubility and bioavailability confers upon CPP potential to be biological delivery vehicles for calcium and phosphate. Purpose: The aim of this study was to determine the calcium levels in tooth enamel after being covered with CPP-ACP 2 times a day for 3, 14 and 28 days. Methods: Sample were bovine incisors of 3 year old cows divided into 4 groups, namely group I as control group, group II, III and IV as treatment groups covered with CPP-ACP 2 times a day. All of those teeth were then immersed in artificial saliva. Group II was immersed for 3 days, while group III was immersed for 14 days, and group IV was immersed for 28 days. One drop of CPP-ACP was used to cover the entire labial surface of teeth. The measurement of the calcium levels was then conducted by using titration method. All data were analyzed by One- Way ANOVA test with 5% degree of confidence. Results: The results showed significant difference of the calcium levels in tooth enamel of those groups after covered with CPP-ACP 2 times a day for 3, 14 and 28 days (p = 0.001. There is also significant difference of the calcium levels in tooth enamel of those treatment groups and the control group (p = 0.001. Conclusion: The calcium levels of tooth enamel are increased after covered with CPP-ACP 2 times a day for 3, 14 and 28 days.Latar belakang: Proses terjadinya karies gigi ditandai oleh adanya demineralisasi

  1. Short-range intercellular calcium signaling in bone

    DEFF Research Database (Denmark)

    Jørgensen, Niklas Rye

    2005-01-01

    whether bone cells are capable of communicating via intercellular calcium signals, and determine by which mechanisms the cells propagate the signals. First, we found that osteoblastic cells can propagate intercellular calcium transients upon mechanical stimulation, and that there are two principally...... to osteoclasts as well. We demonstrated that paracrine action of ATP was responsible for the wave propagation, but now the purinergic P2X7 receptor was involved. Thus, the studies demonstrate that calcium signals can be propagated not only among osteoblasts, but also between osteoblasts and osteoclasts...... in response to mechanical stimulation. Thus, intercellular calcium signaling can be a mechanism by which mechanical stimuli on bone are translated into biological signals in bone cells, and propagated through the network of cells in bone. Further, the observations offer new pharmacological targets...

  2. Synthesis, characterization, and mineralization of polyamide-6/calcium lactate composite nanofibers for bone tissue engineering.

    Science.gov (United States)

    Pant, Hem Raj; Risal, Prabodh; Park, Chan Hee; Tijing, Leonard D; Jeong, Yeon Jun; Kim, Cheol Sang

    2013-02-01

    Polyamide-6 nanofibers containing calcium lactate (CL) on their surface were prepared by neutralization of lactic acid (LA) in core-shell structured polyamide-6/LA electrospun fibers. First, simple blending of LA with polyamide-6 solution was used for electrospinning which interestingly formed a thin LA layer around polyamide-6 nanofibers (core-shell structure) and then subsequent conversion of this LA into calcium lactate via neutralization using calcium base. FE-SEM and TEM images revealed that plasticizer capacity of LA led the formation of point-bonded structure due to the formation of shell layer of LA and core of polyamide-6. The bone formation ability of polyamide-6/calcium lactate composite fibers was evaluated by incubating in biomimetic simulated body fluid (SBF). The SBF incubation test confirmed the faster deposition of large amount of calcium phosphate around the composite polyamide-6/calcium lactate fibers compared to pristine polyamide-6. This study demonstrated a simple post electrospinning calcium compound coating technique of polymeric nanofibers for enhancing the bone biocompatibility of polyamide-6 fibers. PMID:23006560

  3. The flame photometric determination of calcium in phosphate, carbonate, and silicate rocks

    Science.gov (United States)

    Kramer, H.

    1957-01-01

    A flame photometric method of determining calcium in phosphate, carbonate, and silicate locks has been developed Aluminum and phosphate interference was overcome by the addition of a large excess of magnesium. The method is rapid and suitable for routine analysis Results obtained are within ?? 2% of the calcium oxide content. ?? 1957.

  4. Calcium Fructoborate for Bone and Cardiovascular Health.

    Science.gov (United States)

    Mogoşanu, George Dan; Biţă, Andrei; Bejenaru, Ludovic Everard; Bejenaru, Cornelia; Croitoru, Octavian; Rău, Gabriela; Rogoveanu, Otilia-Constantina; Florescu, Dan Nicolae; Neamţu, Johny; Scorei, Iulia Daria; Scorei, Romulus Ion

    2016-08-01

    Calcium fructoborate (CF), a natural sugar-borate ester found in fresh fruits and vegetables, is a source of soluble boron. CF contains three forms of borate (diester, monoester, and boric acid) and all are biologically active, both at the intracellular (as free boric acid) and extracellular level (as fructose-borate diester and monoester). At the cellular and molecular level, CF is superior to the boric acid/borate, exhibiting a complex "protective" effect against inflammatory response. CF is commercially available in the USA as a "nature-identical" complex, an active compound for dietary supplements. It provides effective and safe support against the discomfort and lack of flexibility associated with osteoarticular conditions (arthritis and joint degeneration), and improves Western Ontario and McMaster Universities Osteoarthritis (WOMAC) and McGill indexes. In addition, orally administered CF is effective in ameliorating symptoms of physiological response to stress, including inflammation of the mucous membranes, discomfort associated with osteoarthritis disorders, and bone loss, and also for supporting cardiovascular health. Clinical studies have exhibited the ability of CF to significantly modulate molecular markers associated with inflammatory mechanisms, mainly on the elevated serum levels of C-reactive protein (CRP). PMID:26686846

  5. 冻干硬脑膜内骨形成蛋白-自固化磷酸钙复合移植修复骨缺损%Repairing bone defects using bone morphogenetic protein and calcium phosphate cement combined with freeze-dried dura mater

    Institute of Scientific and Technical Information of China (English)

    邹国耀; 吴恒烜

    2009-01-01

    背景:骨形成蛋白和自固化磷酸钙各自有着良好的成骨能力,冻干硬脑膜内骨形成蛋白和自固化磷酸钙复合移植存在优化成骨效能的可能性.目的:以冻干硬脑膜为膜材料,观察膜内充填材料骨形成蛋白复合自固化磷酸钙移植修复节段性骨缺损的效果.设计、时间及地点:随机分组设计,动物体内组织病理学对照观察,于2006-07/2007-07在广西医科大学动物实验室完成.对象:健康成年新西兰大白兔28只,雌雄不限,体质量1.5~2.5 kg.方法:实验兔28只,其中4只用于取硬脑膜.其余24只随机分成A,B两大组,每组12只.A组制造双侧兔桡骨中段10 mm的骨缺损.一侧骨缺损用骨形成蛋白、自固化磷酸钙、冻干硬脑膜复合移植修复,为骨形成蛋白组, 另一侧不予处理作为空白对照组.B组制造单侧兔桡骨中段10 mm的骨缺损,用骨髓、自固化磷酸钙、冻干硬脑膜复合移植修复称骨髓组.主要观察指标:于术后第1,2,4,6,8,10,12周分别行双侧桡骨X射线检查.观察骨缺损处的新骨形成及骨修复情况.并于术后第2,4,8,12周切取标本行组织学检查及成骨面积分析.结果:在术后第4,8,12周,骨形成蛋白组的成骨面积大于骨髓组(P<0.05),而在实验早期(术后2周)两组间差异无显著性意义(P>0.05);在实验的各个时期,骨形成蛋白组和骨髓组的成骨面积均明显大于空白组(P<0.01).X射线结果显示,骨形成蛋白组在10~12周出现明显骨痂塑形现象;组织学病理切片结果显示,骨形成蛋白组在12周时桡骨可见成熟骨髓,骨缺损处为成熟的板层骨连接.结论:骨形成蛋白复合自固化磷酸钙与冻干硬脑膜移植具有良好的成骨作用.%BACKGROUND: Both bone morphogenetic protein (BMP) and calcium phosphate cement (CPC) have excellent osteogenic capability, so, it is possible to optimize osteogenic efficiency by combing BMP, CPC and freeze-dried dura mater (FDDM

  6. Calcium, vitamin D, and your bones

    Science.gov (United States)

    ... can break easily, even without an obvious injury. Vitamin D helps your body absorb calcium. Eat foods that provide the right amounts of calcium, vitamin D, and protein. This kind of diet will give ...

  7. Analysis of Bone Density in Patients with Urolithiasis; Role of Hypercalciuria in Bone Loss: Do These Patients Need a Low-Calcium Diet?

    Directory of Open Access Journals (Sweden)

    Ali-Asghar Yarmohammadi

    2008-01-01

    Full Text Available Introduction: Kidney stone is a common urologic complaint. In this study, bone density in stone formers was compared with that of a control group; bone density of stone formers was also analyzed based on age, sex and stone configuration. Methods: In a group of 85 patients with upper urinary calcium stones and 85 healthy people, variables such as age, height, weight, BMI, T-score and Z-score results of bone densitometry of lumbar vertebrae (L2-L4 and femoral neck were recorded. The serum levels of uric acid, calcium, potassium, sodium, phosphor, alkaline phosphates and parathyroid hormone were also analyzed and recorded. Furthermore, all patients, 24-hour urine was studied for levels of cr, oxalate, citrate, uric acid calcium, urea and the total volume. Results: Lumbar and femoral bone mineral density (BMD was significantly lower in patients suffering from renal stone. This difference was also significant when the study and control groups were classified into hypercalciuric and normocalciuric ones. Based on the densimetric results of lumbar vertebrae and femoral neck, BMD reduction among menopause women was significantly greater. Conclusion: Noting the lack of relationship between hypercalciuria and bone loss, and noting that a low-calcium diet not only has no proved role in renal stone prevention, but also it leads to calcium imbalance and finally bone loss, low-calcium diets are not suggested for renal stone formers

  8. Augmentation of Pedicle Screw Fixation with Calcium Phosphate Cement

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-hua; FU De-hao; LI Jin; XU Wei-hua; YANG Cao; YE Zhe-wei; ZUO Xiao-yan

    2004-01-01

    To determine whether a biodegradable calcium phosphate cement(CPC) provides significant augmentation of pedicle screw fixation or not,an in vitro biomechanical study was carried out to evaluate the biomechanical effect of CPC in the restoration and augmentation of pedicle screw fixation.Axial pullout test and cyclic bending resistance test were employed in the experiment,and polymethylmethacrylate (PMMA) was chosen as control.The results demonstrate that the pullout strengths following CPC restoration and augmentation are 74% greater on an average than those of the control group,but less than those of PMMA restoration group and augmentation group respectively (increased by 126% versus control).In cyclic bending resistance test,the CPC augmented screws are found to withstand a greater number of cycles or greater loading with less displacement before loosening,but the augmentation effect of PMMA is greater than that of CPC.

  9. Chapter 9: Model Systems for Formation and Dissolution of Calcium Phosphate Minerals

    Energy Technology Data Exchange (ETDEWEB)

    Orme, C A; Giocondi, J L

    2006-07-29

    Calcium phosphates are the mineral component of bones and teeth. As such there is great interest in understanding the physical mechanisms that underlie their growth, dissolution, and phase stability. Control is often achieved at the cellular level by the manipulation of solution states and the use of crystal growth modulators such as peptides or other organic molecules. This chapter begins with a discussion of solution speciation in body fluids and relates this to important crystal growth parameters such as the supersaturation, pH, ionic strength and the ratio of calcium to phosphate activities. We then discuss the use of scanning probe microscopy as a tool to measure surface kinetics of mineral surfaces evolving in simplified solutions. The two primary themes that we will touch on are the use of microenvironments that temporally evolve the solution state to control growth and dissolution; and the use of various growth modifiers that interact with the solution species or with mineral surfaces to shift growth away from the lowest energy facetted forms. The study of synthetic minerals in simplified solution lays the foundation for understand mineralization process in more complex environments found in the body.

  10. Osteogenic activity of cyclodextrin-encapsulated doxycycline in a calcium phosphate PCL and PLGA composite.

    Science.gov (United States)

    Trajano, V C C; Costa, K J R; Lanza, C R M; Sinisterra, R D; Cortés, M E

    2016-07-01

    Composites of biodegradable polymers and calcium phosphate are bioactive and flexible, and have been proposed for use in tissue engineering and bone regeneration. When associated with the broad-spectrum antibiotic doxycycline (DOX), they could favor antimicrobial action and enhance the action of osteogenic composites. Composites of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and a bioceramic of biphasic calcium phosphate Osteosynt® (BCP) were loaded with DOX encapsulated in β-cyclodextrin (βCD) and were evaluated for effects on osteoblastic cell cultures. The DOX/βCD composite was prepared with a double mixing method. Osteoblast viability was assessed with methyl tetrazolium (MTT) assays after 1day, 7day, and 14days of composite exposure; alkaline phosphatase (AP) activity and collagen production were evaluated after 7days and 14days, and mineral nodule formation after 14days. Composite structures were evaluated by scanning electron microscopy (SEM). Osteoblasts exposed to the composite containing 25μg/mL DOX/βCD had increased cell proliferation (pcomposite (pcomposite material revealed a surface topography with pore sizes suitable for growing osteoblasts. Together, these results suggest that osteoblasts are viable, proliferative, and osteogenic in the presence of a DOX/βCD-containing BCP ceramic composite.

  11. Association of calcium and phosphate ions with collagen in the mineralization of vertebrate tissues.

    Science.gov (United States)

    Landis, William J; Jacquet, Robin

    2013-10-01

    Among the vertebrate species, collagen is the most abundant protein and is associated with mineralization of their skeleton and dentition in all tissues except enamel. In such tissues, bones, calcifying tendon, dentin, and cementum are comprised principally of type I collagen, which has been proposed as a template for apatite mineral formation. Recent considerations of the interaction between type I collagen and calcium and phosphate ions as the major constituents of apatite have suggested that collagen polypeptide stereochemistry underlies binding of these ions at sites within collagen hole and overlap regions and leads to nucleation of crystals. The concept is fundamental to understanding both normal and abnormal mineralization, and it is reviewed in this article. Given this background, avenues for additional research studies in vertebrate mineralization will also be described. The latter include, for instance, how mineralization events subsequent to nucleation, that is, crystal growth and development, occur and whether they, too, are directed by collagen stereochemical parameters; whether mineralization can be expected in all spaces between collagen molecules; whether the side chains of charged amino acid residues actually point toward and into the hole and overlap collagen spaces to provide putative binding sites for calcium and phosphate ions; and what phenomena may be responsible for mineralization beyond hole and overlap zones and into extracellular tissue regions between collagen structural units. These questions will be discussed to provide a broader understanding of collagen contributions to potential mechanisms of vertebrate mineralization.

  12. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    Energy Technology Data Exchange (ETDEWEB)

    Pardun, Karoline [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Treccani, Laura, E-mail: treccani@uni-bremen.de [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Volkmann, Eike [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Streckbein, Philipp [University Hospital, Justus-Liebig-University Giessen, Department of Cranio-Maxillo-Facial Surgery, Klinikstrasse 33, 35385 Giessen (Germany); Heiss, Christian [University Hospital of Giessen-Marburg, Department of Trauma Surgery, Rudolf-Buchheim-Strasse 7, 35385 Giessen, Germany, (Germany); Laboratory of Experimental Surgery, Kerkraderstrasse 9, 35392 Giessen (Germany); Destri, Giovanni Li; Marletta, Giovanni [Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI, Viale A. Doria 6, 95125 Catania (Italy); Rezwan, Kurosch [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany)

    2015-03-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic.

  13. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    International Nuclear Information System (INIS)

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic

  14. Electrolytic deposition of calcium phosphate/chitosan coating on titanium alloy: Growth kinetics and influence of current density, acetic acid, and chitosan

    NARCIS (Netherlands)

    Wang, Jiawei; Apeldoorn, van Aart; Groot, de Klaas

    2006-01-01

    Electrolytically deposited calcium phosphate/chitosan coating demonstrated good bone marrow stromal cell attachment. The aim of this study was to understand the coating's growth kinetics as well as the effects of current density, acetic acid, and chitosan on the coating's formation. The scanning ele

  15. Enhancement of biodegradation and osseointegration of poly(ε-caprolactone)/calcium phosphate ceramic composite screws for osteofixation using calcium sulfate.

    Science.gov (United States)

    Wu, Chang-Chin; Hsu, Li-Ho; Tsai, Yuh-Feng; Sumi, Shoichiro; Yang, Kai-Chiang

    2016-04-01

    Internal fixation devices, which can stabilize and realign fractured bone, are widely used in fracture management. In this paper, a biodegradable composite fixator, composed of poly(ε-caprolactone), calcium phosphate ceramic and calcium sulfate (PCL/CPC/CS), is developed. The composition of CS, which has a high dissolution rate, was expected to create a porous structure to improve osteofixation to the composite fixator. PCL, PCL/CPC, and PCL/CPC/CS samples were prepared and their physical properties were characterized in vitro. In vivo performance of the composite screws was verified in the distal femurs of rabbits. Results showed that the PCL/CPC/CS composite had a higher compressive strength (28.55 ± 3.32 MPa) in comparison with that of PCL (20.64 ± 1.81 MPa) (p enhanced apatite formation of the PCL/CPC composite screw. This osteoconductive PCL/CPC/CS is a good candidate material for internal fixation devices. PMID:27041468

  16. Strontium hydroxyapatite and strontium carbonate as templates for the precipitation of calcium-phosphates in the absence and presence of fluoride

    Science.gov (United States)

    Sternitzke, Vanessa; Janousch, Markus; Heeb, Michèle B.; Hering, Janet G.; Johnson, C. Annette

    2014-06-01

    The heterogeneous precipitation of calcium-phosphates on calcium hydroxyapatite (Ca10(PO4)6(OH)2 or HAP) in the presence and absence of fluoride is important in the formation of bone and teeth, protection against tooth decay, dental and skeletal fluorosis and defluoridation of drinking water. Strontium hydroxyapatite (Sr10(PO4)6(OH)2 or SrHAP) and strontium carbonate (SrCO3) were used as calcium-free seed templates in precipitation experiments conducted with varying initial calcium-to-phosphate (Ca/P) or calcium-to-phosphate-to-fluoride (Ca/P/F) ratios. Suspensions of SrHAP or SrCO3 seed templates (which were calcium-limited for both templates and phosphate-limited in the case of SrCO3) were reacted at pH 7.3 (25 °C) over 3 days. The resulting solids were examined with Scanning Transmission Electron Microscopy (STEM), X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Near Edge Structure (XANES), and Extended X-ray Absorption Fine Structure spectroscopy (EXAFS). Calcium apatite was the predominant phase identified by all techniques independent of the added Ca/P ratios and of the presence of fluoride. It was not possible to make an unambiguous distinction between HAP and fluorapatite (Ca10(PO4)6F2, FAP). The apatite was calcium-deficient and probably contained some strontium.

  17. Biphasic calcium phosphate–casein bone graft fortified with Cassia occidentalis for bone tissue engineering and regeneration

    Indian Academy of Sciences (India)

    B Santhosh Kumar; T Hemalatha; R Deepachitra; R Narasimha Raghavan; P Prabu; T P Sastry

    2015-02-01

    Research on traditional herbs is gaining momentum owing to their potent medical properties, among which Cassia occidentalis (CO) is a promising herb, with osteogenic potential. The study investigates the efficacy of CO extract incorporated biphasic calcium phosphate as an osteoinductive material. Prepared bone implants were characterized physico-chemically using FT-IR, TGA, XRD, SEM and EDX. The implants were analysed further for mechanical and biological properties. The results revealed that CO extract-incorporated bone implants possessed better compression strength and it was able to induce proliferation and enhance alkaline phosphatase activity in SaOS-2 cells. The implant proves to be promising for bone tissue engineering, and hence it demands further in vivo evaluation.

  18. Calcium phosphate nanoparticles carrying BMP-7 plasmid DNA induce an osteogenic response in MC3T3-E1 pre-osteoblasts.

    Science.gov (United States)

    Hadjicharalambous, Chrystalleni; Kozlova, Diana; Sokolova, Viktoriya; Epple, Matthias; Chatzinikolaidou, Maria

    2015-12-01

    Functionalized calcium phosphate nanoparticles with osteogenic activity were prepared. Polyethyleneimine-stabilized calcium phosphate nanoparticles were coated with a shell of silica and covalently functionalized by silanization with thiol groups. Between the calcium phosphate surface and the outer silica shell, plasmid DNA which encoded either for bone morphogenetic protein 7 (BMP-7) or for enhanced green fluorescent protein was incorporated as cargo. The plasmid DNA-loaded calcium phosphate nanoparticles were used for the transfection of the pre-osteoblastic MC3T3-E1 cells. The cationic nanoparticles showed high transfection efficiency together with a low cytotoxicity. Their potential to induce an osteogenic response by transfection was demonstrated by measuring the alkaline phosphatase (ALP) activity and calcium deposition with alizarin red staining. The expression of the osteogenic markers Alp, Runx2, ColIa1 and Bsp was investigated by means of real-time quantitative polymerase chain reaction. It was shown that phBMP-7-loaded nanoparticles can provide a means of transient transfection and localized production of BMP-7 in MC3T3-E1 cells, with a subsequent increase of two osteogenic markers, specifically ALP activity and calcium accumulation in the extracellular matrix. Future strategies to stimulate bone regeneration focus into enhancing transfection efficiency and achieving higher levels of BMP-7 produced by the transfected cells.

  19. Mg-doped biphasic calcium phosphate by a solid state reaction route: Characterization and evaluation of cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Webler, Geovana D. [Instituto de Física, Universidade Federal de Alagoas, Maceió-AL 57072970 (Brazil); Correia, Ana C.C.; Barreto, Emiliano [Laboratório de Biologia Celular, Universidade Federal de Alagoas, Maceió-AL 57072970 (Brazil); Fonseca, Eduardo J.S., E-mail: eduardo@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, Maceió-AL 57072970 (Brazil)

    2015-07-15

    Hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP) are widely used in tissue engineering because of their chemical similarity to the inorganic bone phase. In this work, we prepare biphasic calcium phosphate (BCP, a mixture of HAP and β-TCP) doped with different concentrations of magnesium to investigate the influence of magnesium on the BCP crystal structure. Magnesium is known to be an important element in the composition of bones and teeth. Recent research has shown that the doping of magnesium into BCP improves its bone metabolism and mechanical properties without affecting its biocompatibility. The samples were prepared by solid-state reaction from calcium carbonate, monobasic ammonium phosphate, and magnesium nitrate hexahydrate. Varying concentrations of magnesium were used and its modifications were examined by different characterization techniques. The phase composition and morphology of the ceramic powders were characterized by X-ray diffraction and scanning electron microscopy, respectively. The functional groups were analyzed using Fourier transform infrared spectroscopy and Raman spectroscopy. Cell viability experiments, using macrophage-like cell lines J774, showed that the synthesized Mg-doped BCP did not exhibit cytotoxicity regardless of the doses assayed or the different concentrations of magnesium used, suggesting it as a good material for potential biological applications. - Highlights: • Simple and fast method for the preparation of the Mg-BCP. • Study of the influence of the incorporation of Mg in the BCP. • Cell viability showed that the synthesized Mg-BCP did not exhibit cytotoxicity.

  20. Mg-doped biphasic calcium phosphate by a solid state reaction route: Characterization and evaluation of cytotoxicity

    International Nuclear Information System (INIS)

    Hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP) are widely used in tissue engineering because of their chemical similarity to the inorganic bone phase. In this work, we prepare biphasic calcium phosphate (BCP, a mixture of HAP and β-TCP) doped with different concentrations of magnesium to investigate the influence of magnesium on the BCP crystal structure. Magnesium is known to be an important element in the composition of bones and teeth. Recent research has shown that the doping of magnesium into BCP improves its bone metabolism and mechanical properties without affecting its biocompatibility. The samples were prepared by solid-state reaction from calcium carbonate, monobasic ammonium phosphate, and magnesium nitrate hexahydrate. Varying concentrations of magnesium were used and its modifications were examined by different characterization techniques. The phase composition and morphology of the ceramic powders were characterized by X-ray diffraction and scanning electron microscopy, respectively. The functional groups were analyzed using Fourier transform infrared spectroscopy and Raman spectroscopy. Cell viability experiments, using macrophage-like cell lines J774, showed that the synthesized Mg-doped BCP did not exhibit cytotoxicity regardless of the doses assayed or the different concentrations of magnesium used, suggesting it as a good material for potential biological applications. - Highlights: • Simple and fast method for the preparation of the Mg-BCP. • Study of the influence of the incorporation of Mg in the BCP. • Cell viability showed that the synthesized Mg-BCP did not exhibit cytotoxicity

  1. Randomized crossover study comparing the phosphate-binding efficacy of calcium ketoglutarate versus calcium carbonate in patients on chronic hemodialysis

    DEFF Research Database (Denmark)

    Bro, S; Rasmussen, R A; Handberg, J;

    1998-01-01

    into the study. Calculations based on median doses after 12 weeks showed that the cost of the therapy in Denmark was 10 times higher for calcium ketoglutarate compared with calcium carbonate (US$6.00/d v US$0.65/d). Calcium ketoglutarate may be an effective and safe alternative to treatment with aluminum......The objective of the study was to evaluate the phosphate-binding efficacy, side effects, and cost of therapy of calcium ketoglutarate granulate as compared with calcium carbonate tablets in patients on chronic hemodialysis. The study design used was a randomized, crossover open trial, and the main...... outcome measurements were plasma ionized calcium levels, plasma phosphate levels, plasma intact parathyroid hormone (PTH) levels, requirements for supplemental aluminum-aminoacetate therapy, patient tolerance, and cost of therapy. Nineteen patients on chronic hemodialysis were treated with a dialysate...

  2. The influence of feed phosphates on the structural, mechanical and chemical properties of bone tissue in pigs.

    Science.gov (United States)

    Nikodem, A; Dragan, Sz; Kołacz, Sz; Dobrzanski, Z

    2012-01-01

    The aim of the study was to assess the influence of various feed phosphates on the structural and mechanical properties as well as on the chemical composition of femurs in adult pigs (weight approx. 110 kg). Three types of phosphates--monocalcium phosphate (MCP), dicalcium phosphate (n-DCP) and calcium-sodium phosphate (CSP)--were used alternatively in pigs fed with the standard feed mixture. The MCP and CSP phosphates were typical, imported products used traditionally in pig feeding. Dicalcium phosphate (n-DCP) was manufactured in Poland on the basis of phosphoric acid with the new pro-ecological method. The following parameters were determined: the mean physical density of the samples of the compact and spongy bone tissue, values of Young's modulus, strength and the energy of deformation, and Vickers microhardness (HV). Also the content of C, O, Na, Mg, Al, and Si, as well as Ca, P and Sr was determined. Significant differences in mean values of the mentioned parameters occurred between the studied groups. The best mechanical properties were shown by the bones from the n-DCP group, and the compact bone tissue (diaphysis) contained the most Ca, P, and Sr when compared to the MCP and CSP groups.

  3. Hereditary deafness with hydrops and anomalous calcium phosphate deposits

    Energy Technology Data Exchange (ETDEWEB)

    Johnsson, L.G.; Rouse, R.C.; Hawkins, J.E. Jr.; Kingsley, T.C.; Wright, C.G.

    1981-11-01

    The temporal bones from a 58-year-old white woman who had had hereditary congenital deafness were examined with the techniques of microdissection and surface preparations followed by sectioning of the modiolus. There was bilateral, almost total sensorineural degeneration, which also involved the saccule. The degeneration of the distal processes of the cochlear neurons in the osseous spiral lamina was almost complete, whereas numerous ganglion cells and proximal processes remained in the modiolus and the internal auditory canal. Severe cochleo-saccular hydrops was present in the left ear with Reissner's membrane bulging into the horizontal canal. X-ray diffraction and electron probe analysis were used to study the abnormal crystalline deposits in both ears. On the left side the saccular otoconia were composed of calcite, but the utricular macula was covered by a crust of apatite spherulites. More apatite occurred around the maculae and in the scala media. The cupulae were composed of apatite and octacalcium phosphate. On the right side the utricular otoconia were of normal calcite, but there was a deposit of apatite on the macula sacculi. The upper part of the scala media was completely filled by a deposit of apatite and octacalcium phosphate.

  4. Hereditary deafness with hydrops and anomalous calcium phosphate deposits

    International Nuclear Information System (INIS)

    The temporal bones from a 58-year-old white woman who had had hereditary congenital deafness were examined with the techniques of microdissection and surface preparations followed by sectioning of the modiolus. There was bilateral, almost total sensorineural degeneration, which also involved the saccule. The degeneration of the distal processes of the cochlear neurons in the osseous spiral lamina was almost complete, whereas numerous ganglion cells and proximal processes remained in the modiolus and the internal auditory canal. Severe cochleo-saccular hydrops was present in the left ear with Reissner's membrane bulging into the horizontal canal. X-ray diffraction and electron probe analysis were used to study the abnormal crystalline deposits in both ears. On the left side the saccular otoconia were composed of calcite, but the utricular macula was covered by a crust of apatite spherulites. More apatite occurred around the maculae and in the scala media. The cupulae were composed of apatite and octacalcium phosphate. On the right side the utricular otoconia were of normal calcite, but there was a deposit of apatite on the macula sacculi. The upper part of the scala media was completely filled by a deposit of apatite and octacalcium phosphate

  5. Effects of a high intake of unsaturated and saturated oils on intestinal transference of calcium and calcium mobilization from bone in an ovariectomized rat model of osteoporosis.

    Science.gov (United States)

    Chanda, S; Islam, N; Ghosh, T K; Mitra, C

    1999-06-01

    Intestinal transference of calcium and rate of bone turnover were evaluated in ovariectomized rats fed for 15 days with a high amount (30%) of lipid enriched with monounsaturated (groundnut oil), polyunsaturated (sunflower oil) and saturated (coconut oil) fatty acids. The results were compared with those for sham-operated control and ovariectomized groups fed a normal diet (7% groundnut oil). Irrespective of the saturation and unsaturation characteristics, all lipids (edible oils) used in our study considerably decreased the rate of in situ intestinal transference of calcium. Likewise, the activities of intestinal mucosal enzymes, alkaline phosphatase (AP) and calcium ATPase (Ca2+-ATPase) were decreased significantly in all the segments of the small intestine in a descending gradient. Significant changes in bone turnover and bone calcium (Ca) mobilization were confirmed in these animals by marked alterations in plasma AP activity, urinary calcium and phosphate excretion and calcium to creatinine (Ca:creatinine) ratio. Lipid supplementation (30%) in such ovariectomized rats using groundnut oil (monounsaturated), sunflower oil (polyunsaturated) or coconut oil (saturated) for 15 days further enhanced all of the above observed parameters. These results suggest that the intake of high amounts of lipids with different unsaturation and saturation characteristics may be an important factor in determining bone loss in ovariectomized rats.

  6. Monolithic calcium phosphate/poly(lactic acid) composite versus calcium phosphate-coated poly(lactic acid) for support of osteogenic differentiation of human mesenchymal stromal cells.

    Science.gov (United States)

    Tahmasebi Birgani, Zeinab; van Blitterswijk, Clemens A; Habibovic, Pamela

    2016-03-01

    Calcium phosphates (CaPs), extensively used synthetic bone graft substitutes, are often combined with other materials with the aim to overcome issues related to poor mechanical properties of most CaP ceramics. Thin ceramic coatings on metallic implants and polymer-ceramic composites are examples of such hybrid materials. Both the properties of the CaP used and the method of incorporation into a hybrid structure are determinant for the bioactivity of the final construct. In the present study, a monolithic composite comprising nano-sized CaP and poly(lactic acid) (PLA) and a CaP-coated PLA were comparatively investigated for their ability to support proliferation and osteogenic differentiation of bone marrow-derived human mesenchymal stromal cells (hMSCs). Both, the PLA/CaP composite, produced using physical mixing and extrusion and CaP-coated PLA, resulting from a biomimetic coating process at near-physiological conditions, supported proliferation of hMSCs with highest rates at PLA/CaP composite. Enzymatic alkaline phosphatase activity as well as the mRNA expression of bone morphogenetic protein-2, osteopontin and osteocalcin were higher on the composite and coated polymer as compared to the PLA control, while no significant differences were observed between the two methods of combining CaP and PLA. The results of this study confirmed the importance of CaP in osteogenic differentiation while the exact properties and the method of incorporation into the hybrid material played a less prominent role. PMID:26787486

  7. Manufacturing of calcium phosphate scaffolds by pseudomorphic transformation of gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Araujo Batista, H. de.; Batista Cardoso, M.; Sales Vasconcelos, A.; Vinicius Lia Fook, M.; Rodriguez Barbero, M. A.; Garcia Carrodeguas, R.

    2016-08-01

    Carbonated hydroxyapatite (CHAp) and β-tricalcium phosphate (β-TCP) have been employed for decades as constituents of scaffolds for bone regeneration because they chemically resemble bone mineral. In this study, the feasibility to manufacture CHAp/β-TCP scaffolds by pseudomorphic transformation of casted blocks of gypsum was investigated. The transformation was carried out by immersing the precursor gypsum block in 1 M (NH{sub 4}){sub 2}HPO{sub 4}/1.33 M NH{sub 4}OH solution with liquid/solid ratio of 10 mL/g and autoclaving at 120 degree centigrade and 203 kPa (2 atm) for 3 h at least. Neither shape nor dimensions significantly changed during transformation. The composition of scaffolds treated for 3 h was 70 wt.% CHAp and 30 wt.% β-TCP, and their compressive and diametral compressive strengths were 6.5 ± 0.7 and 5.3 ±0.7 MPa, respectively. By increasing the time of treatment to 6 h, the composition of the scaffold enriched in β-TCP (60 wt.% CHAp and 40 wt.% β-TCP) but its compressive and diametral compressive strengths were not significantly affected (6.7 ± 0.9 and 5.4 ± 0.6 MPa, respectively). On the basis of the results obtained, it was concluded that this route is a good approach to the manufacturing of biphasic (CHAp/β-TCP) scaffolds from previously shaped pieces of gypsum. (Author)

  8. STUDY OF AN ASSESSMENT OF THE FATE OF CALCIUM HYDROXY APATITE BLOCK WITH CORTICO CANCELLOUS BONE GRAFT USED IN COMMUNITED FRACTURES OF LONG BONE OF LOWER LIMB

    Directory of Open Access Journals (Sweden)

    Ahmad

    2015-03-01

    Full Text Available INTRODUCTION: In recent years there has been an increasing interest in biologically active calcium phosphate ceramic materials for orthopaedic application. A number of materials from human, animal or non - biological sources have been used to fill defects with or without additional autogenus bone. It would be ideal to have bone substitute w hich is easily fabricated and preserved, is biocompatible with bone, and is biodegradable. The calcium phosphate system, and in particular hydroxyappatite (HA, has long been the subject of intensive investigation. MATERIAL AND METHODS: This observational two year study was undertaken at S.N. Medical College and Hospital, Agra (U.P.. The patients having the comminuted fracture of the long bone of lower limbs were treated with autogenus bone graft and calcium hydroxy Apatite bone block. Functional results w ere presented according to Klemm and Borner (1986 criteria. RESULTS: The total cases studied were 25 out of which 21 cases had fracture of both bones of leg and 4 were of fracture femur. The patients were aged between 15 to 70 years. Most of the patients were males and the common mode of injury was road traffic accident. An excellent result were seen in the majority 9(36% of patients while 8(32% patients showed a good result and 6(24% showed a fair result. 17(68% patients had compound fracture while 8( 32% patients were having closed fracture. CONCLUSION: Calcium Hydroxy Apatite is a suitable alternative to bone graft. There was no evidence of any foreign body reaction and infection at the Calcium Hydroxy Apatite implanted site. There was satisfactory h ealing of all the comminuted fractures. The movement of adjacent joints was nearly normal. No refracture was observed on follow up.

  9. Oxygen isotope correlation of cetacean bone phosphate with environmental water

    Science.gov (United States)

    Yoshida, Naohiro; Miyazaki, Nobuyuki

    1991-01-01

    The variation with time in the oxygen isotope ratio of the oceans is of prime interest in a variety of research fields. An excellent correlation between oxygen isotope ratios of cetacean (whales, dolphins, and porpoises) bone phosphate and their environmental water is found in this study. Bone phosphate samples of dolphins living in fresh waters are more depleted in oxygen 18 than those of cetaceans living in the oceans, reflecting the clear difference in the isotope composition of water. Cetaceans distributed in the higher latitudes in the oceans are more depleted in oxygen 18 than those distributed in the lower latitudes where seawater is slightly enriched in oxygen 18 relative to that in the higher latitudes. The present results provide a promising tool for estimating the oxygen isotope ratio of the oceanic water of the past without assuming water temperature.

  10. Ectopic bone formation cannot occur by hydroxyapatite/β-tricalcium phosphate bioceramics in green fluorescent protein chimeric mice

    International Nuclear Information System (INIS)

    Highlights: ► Firstly, chimeric mouse model could be established successfully by bone marrow transplantation after irradiation. ► Secondly, bone induction can occur in wild-type mice 90 days after implantation, but not occur in chimeric mice. ► Thirdly, destruction of immune function will block osteoinduction by calcium phosphate ceramics. - Abstract: Many studies have shown that calcium phosphate ceramics (CP) have osteoconductive and osteoinductive properties; however, the exact mechanism of bone induction has not yet been reported. This study was performed to investigate if destroying immunological function will influence osteogenesis, to explain the mechanism which is unclear. In this study, twenty C57BL/6 mice were divided into two groups (n = 10), in group 1, a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ceramic was implanted into both the left and right leg muscles of each mouse; in group 2, ten mice experienced lethal irradiation, then were injected bone marrow (BM) cells from green fluorescent protein (GFP) transgenic mice by tail veil, after bone marrow transplantation (BMT), heart, liver, spleen, lung, kidney, and muscle were harvested for biological analysis, after the GFP chimera model was established successfully, the same HA/β-TCP ceramic was implanted into both leg muscles of each mouse immediately after irradiation. 45 and 90 days after implantation, the ceramics of the two groups were harvested to perform with hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining; the results showed that there was no bone formation in group 2, while new bone tissues were detected in group 1. Our findings suggest that the BM cell from GFP transgenic mice is a good biomarker and it could set a good platform for chimera model; it also shows that BM cell is one of cell resources of bone induction, and destruction of immune function will impede osteoinduction by CP. Overall, our results may shed light on clear mechanism study of bone

  11. Ectopic bone formation cannot occur by hydroxyapatite/{beta}-tricalcium phosphate bioceramics in green fluorescent protein chimeric mice

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Lijia [Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu (China); Duan Xin [Department of Orthopaedics, Chengdu Second People' s Hospital, Chengdu (China); Department of Orthopaedics, West China Hospital, Sichuan University, Chengdu (China); Xiang Zhou [Department of Orthopaedics, West China Hospital, Sichuan University, Chengdu (China); Shi Yujun; Lu Xiaofeng; Ye Feng [Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu (China); Bu Hong, E-mail: hongbu@scu.edu.cn [Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu (China); Department of Pathology, West China Hospital, Sichuan University, Chengdu (China)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Firstly, chimeric mouse model could be established successfully by bone marrow transplantation after irradiation. Black-Right-Pointing-Pointer Secondly, bone induction can occur in wild-type mice 90 days after implantation, but not occur in chimeric mice. Black-Right-Pointing-Pointer Thirdly, destruction of immune function will block osteoinduction by calcium phosphate ceramics. - Abstract: Many studies have shown that calcium phosphate ceramics (CP) have osteoconductive and osteoinductive properties; however, the exact mechanism of bone induction has not yet been reported. This study was performed to investigate if destroying immunological function will influence osteogenesis, to explain the mechanism which is unclear. In this study, twenty C57BL/6 mice were divided into two groups (n = 10), in group 1, a hydroxyapatite/{beta}-tricalcium phosphate (HA/{beta}-TCP) ceramic was implanted into both the left and right leg muscles of each mouse; in group 2, ten mice experienced lethal irradiation, then were injected bone marrow (BM) cells from green fluorescent protein (GFP) transgenic mice by tail veil, after bone marrow transplantation (BMT), heart, liver, spleen, lung, kidney, and muscle were harvested for biological analysis, after the GFP chimera model was established successfully, the same HA/{beta}-TCP ceramic was implanted into both leg muscles of each mouse immediately after irradiation. 45 and 90 days after implantation, the ceramics of the two groups were harvested to perform with hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining; the results showed that there was no bone formation in group 2, while new bone tissues were detected in group 1. Our findings suggest that the BM cell from GFP transgenic mice is a good biomarker and it could set a good platform for chimera model; it also shows that BM cell is one of cell resources of bone induction, and destruction of immune function will impede

  12. Effect of ultrafine poly(ε-caprolactone fibers on calcium phosphate cement: in vitro degradation and in vivo regeneration

    Directory of Open Access Journals (Sweden)

    Yang BY

    2016-01-01

    Full Text Available Boyuan Yang,1 Yi Zuo,1 Qin Zou,1 Limei Li,1 Jidong Li,1 Yi Man,2 Yubao Li1 1Research Center for Nano Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu, People’s Republic of China; 2State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, People’s Republic of China Abstract: We incorporated ultrafine polymer fibers into calcium phosphate cement (CPC to improve the resorption rate of CPC with fiber degradation. Different weight percentages of electrospun poly(ε-caprolactone fibers (0%, 3%, and 7%, named as ultrafine fiber-incorporated CPC0 [UFICPC0], UFICPC3, and UFICPC7 were included into preset CPC specimens for in vitro immersion in lipase phosphate-buffered solution and long-term in vivo implantation in the femoral condyle of rabbits. The effect of the ultrafine poly(ε-caprolactone fibers with a diameter ranging from nanometer to micrometer on CPC degradation was evaluated by measuring the pH of the medium, mass loss, porosity, and physiochemical properties. For the in vivo evaluation, histomorphometrical analysis as well as three-dimensional (3D reconstruction was applied to assess the osteogenic properties of the CPC composite. After in vitro immersion and in vivo implantation, the total porosity and macroporosity as well as the bone formation and ingrowth increased significantly during time in the fiber-incorporated CPC specimens. After 24 weeks of implantation, the degraded space was occupied by newly formed bone, and the UFICPC3 and UFICPC7 composites showed a ~3.5 times higher fraction of bone volume than that of the pristine CPC (UFICPC0. In vitro and in vivo results proved that the introduction of ultrafine degradable fibers within a CPC matrix can be used to improve macroporosity efficiently and enhance CPC degradation and bone ingrowth largely. Keywords: ultrafine fibers, calcium phosphate cement, macroporosity, degraded space, bone ingrowth

  13. Randomized crossover study comparing the phosphate-binding efficacy of calcium ketoglutarate versus calcium carbonate in patients on chronic hemodialysis.

    Science.gov (United States)

    Bro, S; Rasmussen, R A; Handberg, J; Olgaard, K; Feldt-Rasmussen, B

    1998-02-01

    The objective of the study was to evaluate the phosphate-binding efficacy, side effects, and cost of therapy of calcium ketoglutarate granulate as compared with calcium carbonate tablets in patients on chronic hemodialysis. The study design used was a randomized, crossover open trial, and the main outcome measurements were plasma ionized calcium levels, plasma phosphate levels, plasma intact parathyroid hormone (PTH) levels, requirements for supplemental aluminum-aminoacetate therapy, patient tolerance, and cost of therapy. Nineteen patients on chronic hemodialysis were treated with a dialysate calcium concentration of 1.25 mmol/L and a fixed alfacalcidol dose for at least 2 months. All had previously tolerated therapy with calcium carbonate. Of the 19 patients included, 10 completed both treatment arms. After 12 weeks of therapy, the mean (+/-SEM) plasma ionized calcium level was significantly lower in the ketoglutarate arm compared with the calcium carbonate arm (4.8+/-0.1 mg/dL v 5.2+/-0.1 mg/dL; P = 0.004), whereas the mean plasma phosphate (4.5+/-0.3 mg/dL v 5.1+/-0.1 mg/dL) and PTH levels (266+/-125 pg/mL v 301+/-148 pg/mL) did not differ significantly between the two treatment arms. Supplemental aluminum-aminoacetate was not required during calcium ketoglutarate treatment, while two patients needed this supplement when treated with calcium carbonate. Five of 17 (29%) patients were withdrawn from calcium ketoglutarate therapy within 1 to 2 weeks due to intolerance (anorexia, vomiting, diarrhea, general uneasiness), whereas the remaining 12 patients did not experience any side effects at all. The five patients with calcium ketoglutarate intolerance all had pre-existing gastrointestinal symptoms; four of them had received treatment with cimetidine or omeprazol before inclusion into the study. Calculations based on median doses after 12 weeks showed that the cost of the therapy in Denmark was 10 times higher for calcium ketoglutarate compared with calcium

  14. Initial Stability Study of Calcium Phosphate Coated Dental Implants

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Thin film of biodegradable calcium phosphate coated on threaded commercially pure titanium( cp- Ti) dental implants has been investigated as one of alternatives to eliminate the problem of the long-term instability of plasma sprayed HA coated implants. In order to compare in-vivo hone-to-implant response behavior among as-machined, HA coated and CMP coated groups, each group was implanted into New Zealand white mature male rabbits for 2 and 6 weeks, and then in- vivo biological behavior was examined in terms of H&E staining. Initial stability and removable torques of implants were compared among three groups. Measured removable torque of CMP coated specimen at 6 wceks after implantation was significantly higher than that of non-coated group, but slightly lower than that of HA coated group, without any inflammatory response at the surrounding of the implants. The initial stability (ISQ value; implant stability quotient ) of CMP coated specimen at 2 weeks after implantation was slightly lower than that of HA coated group and significantly higher than that of non-coated group. However, after 6 weeks, ISQ value of CMP coated group was slightly higher than that of HA coated group and significantly higher than that of non-coated group.

  15. Degree of vinyl conversion in experimental amorphous calcium phosphate composites

    Science.gov (United States)

    Tarle, Z.; Knežević, A.; Matošević, D.; Škrtić, D.; Ristić, M.; Prskalo, K.; Musić, S.

    2009-04-01

    An experimental dental composite, based on amorphous calcium phosphate (ACP) with the potential to arrest caries development and regenerate mineral-deficient tooth structures has recently been developed. The aim of this study was to assess the degree of vinyl conversion (DVC) attained in experimental composites based on zirconia-modified ACP. Photo-activated resins were based on ethoxylated bisphenol A dimethacrylate (EBPADMA) [ETHM series with varying EBPADMA/triethylene glycol dimethacrylate (TEGDMA) molar ratios assigned 0.5-ETHM I, 0.85-ETHM II and 1.35-ETHM III], or 2,2-bis[p-(2'-hydroxy-3'-methacryloxypropoxy)phenyl]-propane (Bis-GMA) [BTHZ series]. To asses a possible effect of filler particle size on DVC, composites containing 60 mass % resin and 40 mass % of either milled ACP (mACP; median diameter d m = 0.9 μm) or coarse ACP (cACP; d m = 6.0 μm) were prepared, and irradiated with LED curing unit for 40 s. The DVC was calculated as the % change in the ratio of the integrated peak areas between the aliphatic and aromatic absorption bands determined by Fourier transform infrared spectroscopy (FTIR). The highest DVCs values were attained in mACP-BTHZ, cACP-BTHZ and mACP-ETHM III formulations. DVC of tested ACP composites (on average (76.76 ± 4.43)%) compares well with or exceeds DVCs values reported for the majority of commercial materials.

  16. Structure and properties of silver-doped calcium phosphate nanopowders

    Indian Academy of Sciences (India)

    RAVINDER PAL SINGH; UMA BATRA

    2016-09-01

    Stable and antimicrobial silver-doped calcium phosphate nanopowders were synthesized using sol–gel route by setting the atomic ratio of Ag/(Ag +Ca) at 3%and (Ca $+$ Ag)/P at 1.67. Prior to synthesis of nanopowders, influence of time of hydrolyzation on pH and density of precursors were comprehensively studied. Hydrolyzation time was found to have profound influence on pH of constituent precursors. Sufficient hydrolysis resulted in early maturation of sol. Scanning electron microscopy (SEM) showed the heterogeneous and agglomerated state of particles with average size of $3.9\\pm 1.9$ $\\mu$m. Energy dispersive X-ray spectroscopy (EDX) presented uniform distributionof O, Ag, Ca and P elements in nanopowder. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of apatitic structure, whereas X-ray diffraction (XRD) revealed the multiphase constitution of nanopowdersprimarily composed of $\\beta$-TCP, Ag and other hybrid phases. Crystallite size and lattice parameters of $\\beta$-TCP and Ag phases were increased with the rise in calcination temperature. Thermogravimetric analysis (TGA) showed threeregions of weight change and indicated the high thermal stability of nanopowders. Disk diffusion method was used to test the antimicrobial resistance of nanopowders against Escherichia coli and Staphylococcus aureus bacterial strains. All nanopowders exhibited antimicrobial resistance against both E. coli and S. aureus bacteria.

  17. Hardness and microplasticity of nanocrystalline and amorphous calcium phosphate coatings

    Science.gov (United States)

    Ievlev, V. M.; Kostyuchenko, A. V.; Darinskii, B. M.; Barinov, S. M.

    2014-02-01

    The hardness of thin (1.0-4.0 μm) hydroxyapatite coatings with different structures (nanocrystalline, amorphous-crystalline, and amorphous) grown by rf magnetron sputtering on Ti and Si plates has been studied using the nanoindentation method. All the grown structures are characterized by the strain which has reversible and irreversible components. The hardness of nanocrystalline coatings (about 10 GPa) corresponds to the average hardness of hydroxyapatite single crystals. The structure of nanocrystalline coatings in the indentation zone and outside it has been investigated and changes in the structure under the indenter have been revealed using high-resolution transmission electron microscopy. From a comparison of the hardnesses of coatings with different structures and based on an analysis of the intragranular structure, it has been assumed that the plastic deformation occurs according to a dislocation-free mechanism. The plastic deformation is interpreted in terms of the cluster representation of the hydroxyapatite structure and amorphous calcium phosphates of the same elemental composition and cluster-boundary sliding during the deformation.

  18. Effect of biomineralization on collagen-calcium phosphate composition and ultrastructure in artificial bone synthesis%人工骨合成中生物矿化条件对胶原-磷酸钙复合物组成及微观结构的影响

    Institute of Scientific and Technical Information of China (English)

    黄兆龙; 何英; 蔡群; 郭俊明

    2006-01-01

    BACKGROUND: Study on bone tissue-engineered material is one of the most successful fields in tissue engineering, but the mechanism on synthesis of artificial bone has not been known in many aspects.OBJECTIVE: To explore the mechanism of collagen and calcium phosphate (CP) in artificial bone synthesis.DESIGN: Single sample experiment was designed.SETTING: Material Research Room of Honghe University.MATERIALS: The experiment was performed in Material Research Room of Honghe University from July to August 2003. The materials included collagen (10 g/L acetic acid solution), calcium chloride, sodium dihydrogen phosphate (SDP), sodium hydroxide (NaOH), Tris, hydrochloric acid and deionized water (DI water).METHODS: Liquid nitrogen freezing and freeze-drying were used to prepare collagen-CP complexes A and B and the samples at different times during mineralization. UV spectrophotometer was used to determine the biomineralized dynamic curve of collagen-CP. Based on law of curve, the different times of sample collection were determined in preparation of electronic microscopic samples. According to electronic microscopic pictures and spectral data, mechanism analysis was carried on.MAIN OUTCOME MEASURES: Morphology of collagen-CP complex and law of its structure with time changeRESULTS: ①Under agitation, collagen-CP complex A was sheaf-like or needle-like in structure manufactured with retarded neutralization. ②Under static state, with biomineralization, collagen-CP complex B was in layered structure at initial phase of mineralization, which was similar to the self-assembled structure of pure collagen and the molarratio of C, O, P and Ca was 7.26: 20: 0: 2. At the end of mineralization, the structure was strip-like in high density with a certain grains and very fine rills and the molar ratio of C, O, P and Ca was 11.02: 22.5:1.06: 2.CONCLUSION: At the early phase of biomineralization, collagen iscoordinated initially with calcium ion, calcium-carrier layered collagen

  19. Calcium isotope ratios in animal and human bone

    Science.gov (United States)

    Reynard, L. M.; Henderson, G. M.; Hedges, R. E. M.

    2010-07-01

    Calcium isotopes in tissues are thought to be influenced by an individual's diet, reflecting parameters such as trophic level and dairy consumption, but this has not been carefully assessed. We report the calcium isotope ratios (δ 44/42Ca) of modern and archaeological animal and human bone ( n = 216). Modern sheep raised at the same location show 0.14 ± 0.08‰ higher δ 44/42Ca in females than in males, which we attribute to lactation by the ewes. In the archaeological bone samples the calcium isotope ratios of the herbivorous fauna vary by location. At a single site, the archaeological fauna do not show a trophic level effect. Humans have lower δ 44/42Ca than the mean site fauna by 0.22 ± 0.22‰, and the humans have a greater δ 44/42Ca range than the animals. No effect of sex or age on the calcium isotope ratios was found, and intra-individual skeletal δ 44/42Ca variability is negligible. We rule out dairy consumption as the main cause of the lower human δ 44/42Ca, based on results from sites pre-dating animal domestication and dairy availability, and suggest instead that individual physiology and calcium intake may be important in determining bone calcium isotope ratios.

  20. Reflections on the Mechanism of Calcium Phosphate Nucleation on Titanium in Simulated Body Fluids

    Institute of Scientific and Technical Information of China (English)

    F. T. Cheng

    2005-01-01

    The results and main findings of studies reported in the literature in relation to the deposition of calcium phosphate on Ti in simulated body fluids are summarized. The effects of the surface hydroxyl groups and the sign of surface charge on the nucleation of calcium phosphate are reviewed. One major controversy among the conclusions of different studies is the order of adsorption of the calcium ions and the phosphate ions in the initial stage of immersion. A simple model based on the amphoteric nature of the hydroxyl groups on Ti is proposed in an attempt to delineate the nucleation process for calcium phosphate on Ti in simulated body fluids. HPO42- ions interact with the hydroxyl groups via ion exchange and/or electrostatic attraction, and Ca2+ ions, via electrostatic attraction only. There is no preferential order of adsorption. Seemingly inconsistent results in different studies possibly arise from different prior treatments of the samples, which affect the adsorption properties.

  1. Characterization of a silver-incorporated calcium phosphate film by RBS and its antimicrobial effects

    Energy Technology Data Exchange (ETDEWEB)

    Han, I-H [Institute of Physics and Applied Physics, and Atomic-Scale Surface Science Research Center, Yonsei University, Seou1 120-749 (Korea, Republic of); Lee, I-S [Institute of Physics and Applied Physics, and Atomic-Scale Surface Science Research Center, Yonsei University, Seou1 120-749 (Korea, Republic of); Song, J-H [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Lee, M-H [Department of Medical Engineering, Yonsei University, Seoul 120-752 (Korea, Republic of); Park, J-C [Department of Medical Engineering, Yonsei University, Seoul 120-752 (Korea, Republic of); Lee, G-H [Korea Institute of Machinery and Materials, Chang-Won 641-010 (Korea, Republic of); Sun, X-D [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Chung, S-M [Implantium Research Center, Seoul 135-879 (Korea, Republic of)

    2007-09-15

    A thin calcium phosphate film was synthesized on both commercially pure Ti and Si wafers by electron beam evaporation of hydroxyapatite as an evaporant with simultaneous Ar ion beam bombardments. Silver was introduced into an ion-beam-assisted deposition of a calcium phosphate thin film for antimicrobial effect. The amount of incorporated silver ions was controlled by immersing calcium-phosphate-coated samples in different AgNO{sub 3} concentrations, and Rutherford backscattering spectrometry (RBS) was employed to measure the amounts of substituted silver. The higher concentration of silver in the calcium phosphate film was more effective in reducing the bacteria of Escherichia coli ATCC 8739 and Streptococcus mutans OMZ 65 on contact with respect to controls.

  2. Balloon vetebroplasty with calcium phosphate cement augmentation for direct restoration of traumatic thoracolumbar vertebral fractures

    NARCIS (Netherlands)

    Verlaan, JJ; van Helden, WH; Oner, FC; Verbout, AJ; Dhert, WJA

    2002-01-01

    Study Design. A human cadaveric model was used to evaluate balloon vertebroplasty in traumatic vertebral fractures. Objectives. To assess the feasibility and safety of balloon vertebroplasty followed by calcium phosphate cement augmentation to prevent recurrent kyphosis. Summary of Background Data.

  3. Evaluation of Calcium Phosphate Cement As a Root Canal Sealer Filling Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Calcium phosphate cement for root end sealing was obtained by mixing α-tricalcium phosphate and additives with an aqueous solution of citric. Powder and liquid were mixed at a ratio of 1.25g/mL. The biocompatibility of this material was investigated primarily by subcutaneous implantation tests. Then calcium phosphate cement was used to fill three adult dogs' root canal, both calcium hydroxide paste and hydroxyapatite paste as control. The animals were killed at 4,12,20 weeks postoperatively respectively. The effects of different materials on the apical closure, restoration of periapical tissues and adaptability to the dentinal surface were examined by optical and electronic microscope. The observation at 20 weeks shows that the calcium phosphate cement has the potentialities of being a root canal sealer filling material available for pulpless teeth with open-apex and destructive periapical tissue.

  4. Calcite as a bone substitute. Comparison with hydroxyapatite and tricalcium phosphate with regard to the osteoblastic activity

    Energy Technology Data Exchange (ETDEWEB)

    Monchau, F., E-mail: Francine.monchau@univ-artois.fr [Laboratoire Genie Civil et geo-Environnement (EA 4515, Universite Lille Nord de France), Equipe Biomateriaux Artois (Universite d' Artois), IUT/GMP, 1230, rue de l' Universite, BP 819, 62408 Bethune cedex (France); Hivart, Ph.; Genestie, B. [Laboratoire Genie Civil et geo-Environnement (EA 4515, Universite Lille Nord de France), Equipe Biomateriaux Artois (Universite d' Artois), IUT/GMP, 1230, rue de l' Universite, BP 819, 62408 Bethune cedex (France); Chai, F. [Laboratoire Medicaments et Biomateriaux a Liberation Controlee (INSERM U 1008, Universite Lille Nord de France), Groupe de Recherche sur les Biomateriaux (Universite Lille-2), Faculte de Medecine, 1, place de Verdun, 59045 Lille cedex (France); and others

    2013-01-01

    Close to the bone mineral phase, the calcic bioceramics, such as hydroxyapatite (HA) and {beta}-tricalcium phosphate ({beta}-TCP), are commonly used as substitutes or filling materials in bone surgery. Besides, calcium carbonate (CaCO{sub 3}) is also used for their excellent biocompatibility and bioactivity. However, the problem with the animal-origin aragonite demands the new technique to synthesize pure calcite capable of forming 3D bone implant. This study aims to manufacture and evaluate a highly-pure synthetic crystalline calcite with good cytocompatibility regarding to the osteoblasts, comparing to that of HA and {beta}-TCP. After the manufacture of macroporous bioceramic scaffolds with the identical internal architecture, their cytocompatibility is studied through MC3T3-E1 osteoblasts with the tests of cell viability, proliferation, vitality, etc. The results confirmed that the studied process is able to form a macroporous material with a controlled internal architecture, and this synthesized calcite is non-cytotoxic and facilitate the cell proliferation. Indeed requiring further improvement, the studied calcite is definitely an interesting alternative not only to coralline aragonite but also to calcium phosphate ceramics, particularly in bone sites with the large bone remodelling. Highlights: Black-Right-Pointing-Pointer Macroporous calcite manufacturing with controlled architecture as bone substitute Black-Right-Pointing-Pointer Cytotoxicity: adaptation of the colony-forming method with the target cells: MC3T3-E1 osteoblasts Black-Right-Pointing-Pointer Study of osteoblast proliferation and activity on calcite, HA and TCP.

  5. Simplified estimates of ion-activity products of calcium oxalate and calcium phosphate in mouse urine.

    Science.gov (United States)

    Tiselius, Hans-Göran; Ferraz, Renato Ribeiro Nogueira; Heilberg, Ita Pfeferman

    2012-08-01

    This study aimed at formulating simplified estimates of ion-activity products of calcium oxalate (AP(CaOx)) and calcium phosphate (AP(CaP)) in mouse urineto find the most important determinants in order to limit the analytical work-up. Literature data on mouse urine composition was used to determine the relative effect of each urine variable on the two ion-activity products. AP(CaOx) and AP(CaP) were calculated by iterative approximation with the EQUIL2 computerized program. The most important determinants for AP(CaOx) were calcium, oxalate and citrate and for AP(CaP) calcium, phosphate, citrate, magnesium and pH. Urine concentrations of the variables were used. A simplified estimate of AP(CaOx) (AP(CaOx)-index(MOUSE)) that numerically approximately corresponded to 10(8) × AP(CaOx) was given the following expression:[Formula: see text]For a series of urine samples with various composition the coefficient of correlation between AP(CaOx)-index(MOUSE) and 10(8) × AP(CaOx) was 0.99 (p = 0.00000). A similar estimate of AP(CaP) (AP(CaP)-index(MOUSE)) was formulated so that it approximately would correspond numerically to 10(14) × AP(CaP) taking the following form:[Formula: see text]For a series of variations in urine composition the coefficient of correlation was 0.95 (p = 0.00000). The two approximate estimates shown in this article are simplified expressions of AP(CaOx) and AP(CaP). The intention of these theoretical calculations was not to get methods for accurate information on the saturation levels in urine, but to have mathematical tools useful for rough conclusions on the outcome of different experimental situations in mice. It needs to be emphasized that the accuracy will be negatively influenced if urine variables not included in the formulas differ very much from basic concentrations.

  6. Influence of Ethylene Glycol on the Formation of Calcium Phosphate Nanocrystals

    Institute of Scientific and Technical Information of China (English)

    Yi ZUO; Yubao LI; Jie WEI; Yonggang YAN

    2003-01-01

    A synthesis route of using calcium hydroxide Ca(OH)2 with ethylene glycol solvent and orthophosphoric acid (H3PO4)as reagents is described. Three ratios of ethylene glycol to distilled water 1:0, 1:1 and 0:1 are used as diluting media for Ca(OH)2. Crystals of different morphology and composition are formed under weak alkaline circumstance at pH 7.0~8.0. Acicular calcium phosphate nanocrystals are prepared in pure ethylene glycol while rod-like calcium phosphate nanocrystals form in pure distilled water. The nanograde size of the former is smaller than that of the latter. Calcium-deficient apatite (CDAP) is obtained with a Ca/P molar ratio of 1.66. Therefore, it was deduced that the usage of ethylene glycol solvent could influence the formation of calcium phosphate crystal lattice.

  7. Accelerating calcium phosphate growth on NaOH-treated poly-(lactic- co-glycolic acid) by evaporation-induced surface crystallization

    Science.gov (United States)

    Duan, Ke; Tang, Allen; Wang, Rizhi

    2008-12-01

    Poly(lactic- co-glycolic acid) (PLGA) is a promising material for the regeneration of bone tissue, but its surface properties are not optimal for the application. Coating the surface of PLGA with a continuous layer of calcium phosphate is an effective approach to address the limitation. Current coating techniques for PLGA require immersion in supersaturated calcium phosphate solutions for days to weeks. In this study, we report a simple technique to accelerate the coating process to only 2 h immersion in supersaturated solutions. PLGA pellets were first treated with NaOH to increase their hydrophilicity. The NaOH-treated PLGA pellets were repeatedly dipped in a supersaturated calcium phosphate solution and dried in air. After 10 times of the dip-and-dry treatment, a layer of calcium phosphate crystallites uniformly covered the surfaces of the pellets. After the crystallite-covered pellets were immersed in the supersaturated solution for 2 h, about 5-μm thick continuous calcium phosphate coatings formed on the surfaces. The dip-and-dry technique was also applied on a variety of metals and porous structures. An evaporation-induced surface crystallization process was suggested as the mechanism for the dip-and-dry treatment.

  8. Vitamins and bone health: beyond calcium and vitamin D.

    Science.gov (United States)

    Ahmadieh, Hala; Arabi, Asma

    2011-10-01

    Osteoporosis is a major health disorder associated with an increased risk of fracture. Nutrition is among the modifiable factors that influence the risk of osteoporosis and fracture. Calcium and vitamin D play important roles in improving bone mineral density and reducing the risk of fracture. Other vitamins appear to play a role in bone health as well. In this review, the findings of studies that related the intake and/or the status of vitamins other than vitamin D to bone health in animals and humans are summarized. Studies of vitamin A showed inconsistent results. Excessive, as well as insufficient, levels of retinol intake may be associated with compromised bone health. Deficiencies in vitamin B, along with the consequent elevated homocysteine level, are associated with bone loss, decreased bone strength, and increased risk of fracture. Deficiencies in vitamins C, E, and K are also associated with compromised bone health; this effect may be modified by smoking, estrogen use or hormonal therapy after menopause, calcium intake, and vitamin D. These findings highlight the importance of adequate nutrition in preserving bone mass and reducing the risk of osteoporosis and fractures.

  9. 磷酸钙骨水泥复合物/脐带间充质干细胞凝胶构建组织工程骨%An injectable calcium phosphate-alginate hydrogel with umbilical cord mesenchymal stem cell composite for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    赵亮; Hockin Xu; 王健; 史占军

    2012-01-01

    目的 构建新型可注射强化型磷酸钙骨水泥复合物/脐带间充质干细胞凝胶组织工程骨,探讨其力学性能,细胞活性和成骨作用.方法 选用第四代hUCMSCs,1.2%海藻酸钠水凝胶构建hUCMSCs水凝胶微球.高温煅烧钙/磷比约为1.9的磷酸氢钙和碳酸钙混合物,按摩尔质量比以1:1混合制备CPC粉末.15% Chitosan,8mm长度可吸收纤维用于提高CPC复合物力学强度.实验组分为四组:(1)单纯hUCMSCs微球;(2) CPC hUCMSCs微球;(3) CPC+ chitosan+ hUCMSCs微球;(4) CPC+ chitosan+可吸收纤维+hUCMSCs微球,分别检测力学性能,细胞活性和成骨作用.结果 新型组织工程骨力学性能显著增强,抗弯曲强度提高到(11.7±2.1)MPa,弹性模量提高到(2.0±0.4)GPa,断裂功提高到(1.65±0.66) kj/m2(P<0.05).hUCMSCs的ALP活性第7天时明显增高,第14天时达峰,第21天时有所减弱,各组间比较无明显统计学差异(P>0.1).第7天时,所有实验组中的hUCMSCs均见少量矿物合成.第14天和第21天时,矿物合成数量明显增多.hUCMSCs中ALP 基因表达培养第1天最低,第4天达峰,第8天时稍减弱.OC基因表达第8天达峰.结论 构建完成新型可注射强化型磷酸钙骨水泥/脐带间充质干细胞凝胶构建组织工程骨.水凝胶微球中hUCMSCs在CPC中具有良好的成骨作用.CPC-chitosan-可吸收纤维组织工程骨力学性能满足松质骨力学要求,支持水凝胶微球中hUCMSCs的细胞活性和成骨作用.为组织工程骨研究和临床应用提供新思路和新方法.%Objective To develop a novel injectable composite of calcium phosphate-alginate hydrogel and umbilical cord mesenchymal stem cells for bone tissue engineering,and evaluate its mechanical properties and osteogenesis.Methods The fourth generation hUCMSCs and 1.2% sodium alginate hydrogel were used to build hUCMSCs beads.High-temperature calcinationdicalcium phosphate with a Ca/P ratio of approximately 1.9 was mixed with calcium

  10. Osteogenic and antimicrobial nanoparticulate calcium phosphate and poly-(D,L-lactide-co-glycolide) powders for the treatment of osteomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Uskoković, Vuk, E-mail: vuk21@yahoo.com [Therapeutic Micro and Nanotechnology Laboratory, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA (United States); Hoover, Charles [Department of Cell and Tissue Biology, University of California, San Francisco, CA (United States); Vukomanović, Marija [Institute of Technical Sciences, Serbian Academy of Sciences and Arts, Belgrade (Serbia); Advanced Materials Department, Jožef Stefan Institute, Ljubljana (Slovenia); Uskoković, Dragan P. [Institute of Technical Sciences, Serbian Academy of Sciences and Arts, Belgrade (Serbia); Desai, Tejal A. [Therapeutic Micro and Nanotechnology Laboratory, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA (United States)

    2013-08-01

    Development of a material for simultaneous sustained and localized delivery of antibiotics and induction of spontaneous regeneration of hard tissues affected by osteomyelitis stands for an important clinical need. In this work, a comparative analysis of the bacterial and osteoblastic cell response to two different nanoparticulate carriers of clindamycin, an antibiotic commonly prescribed in the treatment of bone infection, one composed of calcium phosphate and the other comprising poly-(D,L-lactide-co-glycolide)-coated calcium phosphate, was carried out. Three different non-cytotoxic phases of calcium phosphate, exhibiting dissolution and drug release profiles in the range of one week to two months to one year, respectively, were included in the analysis: monetite, amorphous calcium phosphate and hydroxyapatite. Spherical morphologies and narrow size distribution of both types of nanopowders were confirmed in transmission and scanning electron microscopic analyses. The antibiotic-containing powders exhibited sustained drug release contingent upon the degradation rate of the carrier. Assessment of the antibacterial performance of the antibiotic-encapsulated powders against Staphylococcus aureus, the most common pathogen isolated from infected bone, yielded satisfactory results both in broths and on blood agar plates for all the analyzed powders. In contrast, no cytotoxic behavior was detected upon the incubation of the antibiotic powders with the osteoblastic MC3T3-E1 cell line for up to three weeks. The cells were shown to engage in a close contact with the antibiotic-containing particles, irrespective of their internal or surface phase composition, polymeric or mineral. At the same time, both types of particles upregulated the expression of osteogenic markers osteocalcin, osteopontin, Runx2 and protocollagen type I, suggesting their ability to promote osteogenesis and enhance remineralization of the infected site in addition to eliminating the bacterial source of

  11. A Comparative Evaluation of the Mechanical Properties of Two Calcium Phosphate/Collagen Composite Materials and Their Osteogenic Effects on Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Qing Li

    2016-01-01

    Full Text Available Adipose-derived stem cells (ADSCs are ideal seed cells for use in bone tissue engineering and they have many advantages over other stem cells. In this study, two kinds of calcium phosphate/collagen composite scaffolds were prepared and their effects on the proliferation and osteogenic differentiation of ADSCs were investigated. The hydroxyapatite/β-tricalcium phosphate (HA/β-TCP composite scaffolds (HTPSs, which have an additional β-tricalcium phosphate, resulted in better proliferation of ADSCs and showed osteogenesis-promoting effects. Therefore, such composite scaffolds, in combination with ADSCs or on their own, would be promising for use in bone regeneration and potential clinical therapy for bone defects.

  12. Calcium Phosphate as a Key Material for Socially Responsible Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Vuk Uskoković

    2016-06-01

    Full Text Available Socially responsible technologies are designed while taking into consideration the socioeconomic, geopolitical and environmental limitations of regions in which they will be implemented. In the medical context, this involves making therapeutic platforms more accessible and affordable to patients in poor regions of the world wherein a given disease is endemic. This often necessitates going against the reigning trend of making therapeutic nanoparticles ever more structurally complex and expensive. However, studies aimed at simplifying materials and formulations while maintaining the functionality and therapeutic response of their more complex counterparts seldom provoke a significant interest in the scientific community. In this review we demonstrate that such compositional simplifications are meaningful when it comes to the design of a solution for osteomyelitis, a disease that is in its natural, non-postoperative form particularly prevalent in the underdeveloped parts of the world wherein poverty, poor sanitary conditions, and chronically compromised defense lines of the immune system are the norm. We show that calcium phosphate nanoparticles, which are inexpensive to make, could be chemically designed to possess the same functionality as a hypothetic mixture additionally composed of: (a a bone growth factor; (b an antibiotic for prophylactic or anti-infective purposes; (c a bisphosphonate as an antiresorptive compound; (d a viral vector to enable the intracellular delivery of therapeutics; (e a luminescent dye; (f a radiographic component; (g an imaging contrast agent; (h a magnetic domain; and (i polymers as viscous components enabling the injectability of the material and acting as carriers for the sustained release of a drug. In particular, calcium phosphates could: (a produce tunable drug release profiles; (b take the form of viscous and injectable, self-setting pastes; (c be naturally osteo-inductive and inhibitory for osteoclastogenesis

  13. Subcutaneous ectopic osteogenesis induced by porous calcium phosphate cement and gelatin sponge as the carrier of recombinant bone morphogenetic protein-2 in rats:A comparative study%两种材料复合rhBMP-2诱导大鼠皮下异位成骨的比较研究

    Institute of Scientific and Technical Information of China (English)

    李想; 董纪元; 彭江; 汪爱媛; 睢翔; 赵斌; 刘道宏

    2011-01-01

    Objective To analyze the difference in subcutaneous ectopic osteogenesis induced by porous calcium phosphate cement (CPC) and gelatin sponge as a carrier of recombinant bone morphogenetic protein-2 (rhBMP-2). Methods Thirty Sprague Dawley rats with an average body weight of 200g were divided into groups A-D. CPC+rhBMP-2, CPC, gelatin sponge+rhBMP-2, and gelatin sponge were implanted into the rats after anesthesia. Ten rats were killed 2, 4 and 8 weeks after they were fed under sterile environment. Bone tissue samples were collected from the implantation sites. Tissue mineral density (TMD) and trabecular thickness were detected with micro-CT scanner and analyzed with SPSS 1 OX) statistical software. Bone tissue was fixed in 4% paraformaldehyde for 2 days, embedded in paraffin, and cut into sections. The sections were stained with H&E to observe their histological change. Results The tissue mineral density and trabecular thickness of the samples with rhBMP-2 were higher in two experimental groups 2,4 and 8 weeks after implantation, which increased with the prolongation of time (P<0.05). Conclusion Porous CPC can be used as a carrier of rhBMP-2 for osteogenesis.%目的 分析多孔自固化磷酸钙骨水泥(Calcium Phosphate Cement,CPC)和明胶海绵复合重组人骨形态发生蛋白(Recombinantion Humen Bone Morphogenetic Protein-2,rhBMP-2)诱导大鼠皮下异位成骨的区别.方法 平均质量200g SD大鼠30只,麻醉后分别植入A:多孔CPC复合rhBMP-2(2μg);B:多孔CPC;C:明胶海绵复合rhBMP-2(2μg);D:空白明胶海绵,无菌喂养后分别于2、4、8周各处死10只.对植入部位组织取材,分别进行micro-CT扫描,并使用Micview V2.1三维重建处理软件扫及ABA骨形态分析软件检测,记录组织骨密度(Tissue Mineral Density,TMD)及骨小梁厚度(Trabecular Thickness,Tb.Th).运用SPSS10.0统计软件进行统计学分析.后行甲醛固定2周,石蜡包埋切片,HE染色进行组织学观察.结果 在2、4、8

  14. A new iron calcium phosphate material to improve the osteoconductive properties of a biodegradable ceramic: a study in rabbit calvaria.

    Science.gov (United States)

    Manchón, Angel; Hamdan Alkhraisat, Mohammad; Rueda-Rodriguez, Carmen; Prados-Frutos, Juan Carlos; Torres, Jesús; Lucas-Aparicio, Julia; Ewald, Andrea; Gbureck, Uwe; López-Cabarcos, Enrique

    2015-10-20

    β-tricalcium phosphate (β-TCP) is an osteoconductive and biodegradable material used in bone regeneration procedures, while iron has been suggested as a tool to improve the biological performance of calcium phosphate-based materials. However, the mechanisms of interaction between these materials and human cells are not fully understood. In order to clarify this relationship, we have studied the iron role in β-TCP ceramics. Iron-containing β-TCPs were prepared by replacing CaCO3 with C6H5FeO7 at different molar ratios. X-ray diffraction analysis indicated the occurrence of β-TCP as the sole phase in the pure β-TCP and iron-containing ceramics. The incorporation of iron ions in the β-TCP lattice decreased the specific surface area as the pore size was shifted toward meso- and/or macropores. Furthermore, the human osteoblastlike cell line MG-63 was cultured onto the ceramics to determine cell proliferation and viability, and it was observed that the iron-β-TCP ceramics have better cytocompatibility than pure β-TCP. Finally, in vivo assays were performed using rabbit calvaria as a bone model. The scaffolds were implanted for 8 and 12 weeks in the defects created in the skullcap with pure β-TCP as the control. The in vivo behavior, in terms of new bone formed, degradation, and residual graft material were investigated using sequential histological evaluations and histomorphometric analysis. The in vivo implantation of the ceramics showed enhanced bone tissue formation and scaffold degradation for iron-β-TCPs. Thus, iron appears to be a useful tool to enhance the osteoconductive properties of calcium phosphate ceramics.

  15. The rate of calcium turnover in bone

    International Nuclear Information System (INIS)

    This paper reports an analysis of the clearance of calcium-47 tracer from the plasma of human patients. Nine subjects have so far been analysed, and the results all deviate somewhat from those predicted from the conventional simple kinetic scheme. 3 figs

  16. The development and characterization of a primarily mineral calcium phosphate - poly(epsilon-caprolactone) biocomposite

    Science.gov (United States)

    Dunkley, Ian Robert

    Orthopaedic reconstruction often involves the surgical introduction of structural implants that provide for rigid fixation, skeletal stabilization, and bone integration. The high stresses incurred by these implanted devices have historically limited material choices to metallic and select polymeric formulations. While mechanical requirements are achieved, these non-degradable materials do not participate actively in the remodeling of the skeleton and present the possibility of long-term failure or rejection. This is particularly relevant in cervical fusion, an orthopaedic procedure to treat damaged, degenerative or diseased intervertebral discs. A significant improvement on the available synthetic bone replacement/regeneration options for implants to treat these conditions in the cervical spine may be achieved with the development of primarily mineral biocomposites comprised of a bioactive ceramic matrix reinforced with a biodegradable polymer. Such a biocomposite may be engineered to possess the clinically required mechanical properties of a particular application, while maintaining the ability to be remodeled completely by the body. A biocomposite of Si-doped calcium phosphate (Si-CaP) and poly(epsilon-caprolactone) (PCL) was developed for application as such a synthetic bone material for potential use as a fusion device in the cervical spine. In this thesis, a method by which high mineral content Si-CaP/PCL biocomposites with interpenetrating matrices of mineral and polymer phases may be prepared will be demonstrated, in addition to the effects of the various preparation parameters on the biocomposite density, porosity and mechanical properties. This new technique by which dense, primarily ceramic Si-CaP/PCL biocomposites were prepared, allowed for the incorporation of mineral contents ranging between 45-97vol%. Polymer infiltration, accomplished solely by passive capillary uptake over several days, was found to be capable of fully infiltrating the microporosity

  17. Development of macroporous calcium phosphate scaffold processed via microwave rapid drying

    International Nuclear Information System (INIS)

    Porous hydroxyapatite (HA) scaffold has great potential in bone tissue engineering applications. A new method to fabricate macroporous calcium phosphate (CP) scaffold via microwave irradiation, followed by conventional sintering to form HA scaffold was developed. Incorporation of trisodium citrate dihydrate and citric acid in the CP mixture gave macroporous scaffolds upon microwave rapid drying. In this work, a mixture of β-tricalcium phosphate (β-TCP), calcium carbonate (CaCO3), trisodium citrate dihydrate, citric acid and double distilled de-ionised water (DDI) was exposed to microwave radiation to form a macroporous structure. Based on gross eye examinations, addition of trisodium citrate at 30 and 40 wt.% in the CP mixture (β-TCP and CaCO3) without citric acid indicates increasing order of pore volume where the highest porosity yield was observed at 40 wt.% of trisodium citrate addition and the pore size was detected at several millimeters. Therefore, optimization of pore size was performed by adding 3-7 wt.% of citric acid in the CP mixture which was separately mixed with 30 and 40 wt.% of trisodium citrate for comparison purposes. Fabricated scaffolds were calcined at 600 deg. C and washed with DDI water to remove the sodium hydroxycarbonate and sintered at 1250 deg. C to form HA phase as confirmed in the X-ray diffraction (XRD) results. Based on Archimedes method, HA scaffolds prepared from 40 wt.% of trisodium citrate with 3-7 wt.% of citric acid added CP mixture have an open and interconnected porous structure ranging from 51 to 53 vol.% and observation using Scanning electron microscope (SEM) showed the pore size distribution between 100 and 500 μm. The cytotoxicity tests revealed that the porous HA scaffolds have no cytotoxic potential on MG63 osteoblast-like cells which might allow for their use as biomaterials.

  18. Osteogenic activity of cyclodextrin-encapsulated doxycycline in a calcium phosphate PCL and PLGA composite.

    Science.gov (United States)

    Trajano, V C C; Costa, K J R; Lanza, C R M; Sinisterra, R D; Cortés, M E

    2016-07-01

    Composites of biodegradable polymers and calcium phosphate are bioactive and flexible, and have been proposed for use in tissue engineering and bone regeneration. When associated with the broad-spectrum antibiotic doxycycline (DOX), they could favor antimicrobial action and enhance the action of osteogenic composites. Composites of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and a bioceramic of biphasic calcium phosphate Osteosynt® (BCP) were loaded with DOX encapsulated in β-cyclodextrin (βCD) and were evaluated for effects on osteoblastic cell cultures. The DOX/βCD composite was prepared with a double mixing method. Osteoblast viability was assessed with methyl tetrazolium (MTT) assays after 1day, 7day, and 14days of composite exposure; alkaline phosphatase (AP) activity and collagen production were evaluated after 7days and 14days, and mineral nodule formation after 14days. Composite structures were evaluated by scanning electron microscopy (SEM). Osteoblasts exposed to the composite containing 25μg/mL DOX/βCD had increased cell proliferation (p<0.05) compared to control osteoblast cultures at all experimental time points, reaching a maximum in the second week. AP activity and collagen secretion levels were also elevated in osteoblasts exposed to the DOX/βCD composite (p<0.05 vs. controls) and reached a maximum after 14days. These results were corroborated by Von Kossa test results, which showed strong formation of mineralization nodules during the same time period. SEM of the composite material revealed a surface topography with pore sizes suitable for growing osteoblasts. Together, these results suggest that osteoblasts are viable, proliferative, and osteogenic in the presence of a DOX/βCD-containing BCP ceramic composite. PMID:27127066

  19. Enzymatic pH control for biomimetic deposition of calcium phosphate coatings

    NARCIS (Netherlands)

    Nijhuis, A.W.G.; Nejadnik, M.R.; Nudelman, F.; Walboomers, X.F.; Riet, J. te; Habibovic, P.; Tahmasebi Birgani, Z.; Li, Y.; Bomans, P.H.; Jansen, J.A.; Sommerdijk, N.A.; Leeuwenburgh, S.C.G.

    2014-01-01

    The current study examines the enzymatic decomposition of urea into carbon dioxide and ammonia as a means to increase the pH during biomimetic deposition of calcium phosphate (CaP) onto implant surfaces. The kinetics of the enzymatically induced pH increase were studied by monitoring pH, calcium con

  20. Comparative study of biphasic calcium phosphate with beta-tricalcium phosphate in rat cranial defects--A molecular-biological and histological study.

    Science.gov (United States)

    Kunert-Keil, Christiane; Scholz, Franziska; Gedrange, Tomasz; Gredes, Tomasz

    2015-05-01

    The aim of this study was to evaluate the in vivo biocompatibility of a biphasic calcium phosphate (BCP) bone graft substitute consisting of 60% hydroxyapatite and 40% β-tricalcium phosphate (β-TCP) in comparison to a pure β-TCP of identical shape and porosity. The materials were evaluated using an established rat cranial defect model in 24 animals. One bone defect with a diameter of 5mm was created per animal. The defects were filled with either BCP or β-TCP and left to heal for 4 weeks. Twelve samples (6 per material) were processed for histological evaluation and immunohistochemistry. The remaining 12 samples were processed for mRNA expression analysis. No signs of inflammation or adverse material reactions were detected. New bone formation in the former defect site did not differ between the two groups (BCP: 49.2%; β-TCP: 52.4%). Osteoblast-like and TRAP-positive osteoclast-like cells were found at the surface of the bone graft substitute granules. The β-TCP group showed significantly higher mRNA levels for the bone resorption marker Acp5 and osteogenic differentiation marker Runx2. The expression of IGF1, IGF2, VEGF, Phex, Alpl, Col1, Col2, Bglap and MMP8 did not differ between the groups. The in vivo biocompatibility of BCP is to a large part identical to those of TCP. Within the limitation of the animal model, the implantation study shows that BCP can be used as bone graft substitute, due to the fact that the material integrates into tissue, remains stable in the implantation bed and serves as an osteoconductive scaffold. PMID:24439994

  1. Influence of whole-body irradiation on calcium and phosphate homeostasis in the rat

    International Nuclear Information System (INIS)

    Previous irradiation studies have revealed marked alterations in calcium metabolism. Moreover, the maintenance of calcium homeostasis with parathyroid hormone or calcium salts has been reported to reduce radiation lethality. Therefore, the present study was designed to evaluate the influence of irradiation on calcium homeostasis in the rat. Nine hundred rad of whole-body irradiation produced a significant depression of both plasma calcium and phosphate at 4 days postirradiation. This effect of irradiation was observed to be dose-dependent over a range of 600 to 1200 rad, and possibly related to irradiation-induced anorexia. The physiological significance of these observations is discussed

  2. DETERMINANTS OF BONE CALCIUM ACCRETION DURING EARLY ADOLESCENCE

    Science.gov (United States)

    Bone mineral status during adolescence may be related to genetic and dietary factors. We evaluated 49 female and 49 male adolescents (Tanner 2/3) randomized to receive 8g of Synergl (Orafti Inc., Belgium), a non-digestible inulin-type fructan daily for a year or placebo. Fractional calcium (Ca) abso...

  3. Nutrition in bone health revisited: a story beyond calcium.

    Science.gov (United States)

    Ilich, J Z; Kerstetter, J E

    2000-01-01

    Osteoporosis is a complex, multi-factorial condition characterized by reduced bone mass and impaired micro-architectural structure, leading to an increased susceptibility to fractures. Although most of the bone strength (including bone mass and quality) is genetically determined, many other factors (nutritional, environmental and life-style) also influence bone. Nutrition is important modifiable factor in the development and maintenance of bone mass and the prevention and treatment of osteoporosis. Approximately 80-90% of bone mineral content is comprised of calcium and phosphorus. Other dietary components, such as protein, magnesium, zinc, copper, iron, fluoride, vitamins D, A, C, and K are required for normal bone metabolism, while other ingested compounds not usually categorized as nutrients (e.g. caffeine, alcohol, phytoestrogens) may also impact bone health. Unraveling the interaction between different factors; nutritional, environmental, life style, and heredity help us to understand the complexity of the development of osteoporosis and subsequent fractures. This paper reviews the role of dietary components on bone health throughout different stages of life. Each nutrient is discussed separately, however the fact that many nutrients are co-dependent and simultaneously interact with genetic and environmental factors should not be neglected. The complexity of the interactions is probably the reason why there are controversial or inconsistent findings regarding the contribution of a single or a group of nutrients in bone health.

  4. Preparation and bioactivity of micro-arc oxidized calcium phosphate coatings

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Y.K. [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji' nan, Shandong 250061 (China); School of Materials Science and Engineering, Shandong University, Ji' nan, Shandong 250061 (China); Chen, C.Z., E-mail: czchen@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji' nan, Shandong 250061 (China); School of Materials Science and Engineering, Shandong University, Ji' nan, Shandong 250061 (China); Wang, D.G.; Lin, Z.Q. [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji' nan, Shandong 250061 (China); School of Materials Science and Engineering, Shandong University, Ji' nan, Shandong 250061 (China)

    2013-09-16

    Calcium phosphate (CaP) coatings were prepared on ZK60 magnesium alloy by micro-arc oxidation (MAO) in electrolyte containing calcium acetate monohydrate (CH{sub 3}COO){sub 2}Ca·H{sub 2}O) and disodium hydrogen phosphate dodecahydrate (Na{sub 2}HPO{sub 4}·12H{sub 2}O). Scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDX) and X-ray diffractometer (XRD) were employed to characterize the microstructure, elemental distribution and phase composition of the CaP coatings respectively. Simulated body fluid (SBF) immersion test was used to evaluate the coating degradability and bioactivity. After 30 days of SBF immersion, the CaP coatings effectively reduce the degradation rate. The surfaces of CaP coatings are covered by a new layer formed of numerous needle-like, spherical and columned calcium phosphates. SEM, EDX and XRD results suggest that these calcium phosphates are bioactive calcium phosphate phases such as hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}, HA) and calcium pyrophosphates (Ca{sub 2}P{sub 2}O{sub 7}, CPP). The formation of these calcium phosphates indicates that the CaP coatings have bioactivity. - Highlights: • Bioactive CaP coatings are successfully formed on ZK60 magnesium alloy. • CaP coatings consist of MgO, MgF{sub 2}, CaO, CaF{sub 2} and Ca{sub 3}(PO{sub 4}){sub 2}. • Needle-like, spherical and columned calcium phosphates formed in SBF. • CaP coatings exhibit bioactivity and low corrosion rate.

  5. Injectable nanoamorphous calcium phosphate based in situ gel systems for the treatment of periapical lesions.

    Science.gov (United States)

    Mostafa, Amany A; Zaazou, Mohamed H; Chow, Laurence C; Mahmoud, Azza A; Zaki, Dalia Y; Basha, Mona; Abdel Hamid, Mohamed A; Khallaf, Maram E; Sharaf, Nehal F; Hamdy, Tamer M

    2015-12-01

    Nonsurgical local treatment of a periapical lesion arising from trauma or bacterial infection is a promising innovative approach. The present study investigated the feasibility of developing injectable amorphous calcium phosphate nanoparticles (ACP NPs) and ACP NPs loaded with an anti-inflammatory drug; ibuprofen (IBU-ACP NPs) in the form of thermoreversible in situ gels to treat periapical lesions with the stimulation of bone formation. NPs were produced by a spray-drying technique. Different formulations of Poloxamer 407 were incorporated with/without the produced NPs to form injectable gels. A drug release study was carried out. A 3 month in vivo test on a dog model also was assessed. Results showed successful incorporation of the drug into the NPs of CP during spray drying. The particles had mean diameters varying from 100 to 200 nm with a narrow distribution. A drug release study demonstrated controlled IBU release from IBU-ACP NPs at a pH of 7.4 over 24 h. The gelation temperature of the injectable in situ gels based on Poloxamer 407 was measured to be 30 °C. After 3 months of implantation in dogs, the results clearly demonstrated that the inclusion of ACP NPs loaded with IBU showed high degrees of periapical bone healing and cementum layer deposition around the apical root tip.

  6. Enhancement of pedicle screw stability using calcium phosphate cement in osteoporotic vertebrae: in vivo biomechanical study.

    Science.gov (United States)

    Taniwaki, Yoshimichi; Takemasa, Ryuichi; Tani, Toshikazu; Mizobuchi, Hiroo; Yamamoto, Hiroshi

    2003-01-01

    We conducted an experimental study using female beagles with and without ovariectomy-induced osteoporosis to determine the effect of calcium phosphate cement (CPC) on the mechanical stability of inserted pedicle screws. A drill hole was created from the base of the transverse process to the vertebral body; CPC was injected into the hole, and then a screw was inserted into the same hole. In the presence of osteoporosis evidenced by dual X-ray absorptiometry, the stability of the inserted screw augmented by CPC against pull-out and cephalocaudal forces were significantly greater by 28% and 54% at 1 week after operation, 48% and 71% at 2 weeks, and 56% and 68% at 4 weeks compared with those without CPC. The pull-out strength increased progressively with time after surgery, probably reflecting new-bone growth from the surrounding cancellous bone, which was in direct contact with the CPC, as shown in the histologic study. At each time point the cephalocaudal rigidity was similar and the pull-out strength greater than that for the screws inserted without CPC in nonporotic dogs. These findings suggest that CPC augments the stability of the inserted pedicle screws and increases the stiffness of fixed osteoporotic motion segments using instrumentation. PMID:12768486

  7. Microanalyses of the hydroxyl—poly—calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    LIUZhong-Yang; WANGChang-Xing; 等

    2002-01-01

    Thin calcium phosphate catings on titanium alloy substrates were prepared by Ar+ ion beam assisted deposition(IBAD) from hydroxyl-poly-calcium sodium phosphate(HPPA) target.The coatings were analyzed by XRD,FTIR,XPS,These analyses revealed that the as-deposited films were amorphous or no apparent crystallinity.No distinct absorption band of the hydroxyl group was observed in FTIR spectra of the coatings but new absorption bands were presented for CO3-2,The calcium to phosphorous ratio of these catings in different IBAD conditions varied from 0.46 to 3.36.

  8. Effect of ultrafine poly(ε-caprolactone) fibers on calcium phosphate cement: in vitro degradation and in vivo regeneration.

    Science.gov (United States)

    Yang, Boyuan; Zuo, Yi; Zou, Qin; Li, Limei; Li, Jidong; Man, Yi; Li, Yubao

    2016-01-01

    We incorporated ultrafine polymer fibers into calcium phosphate cement (CPC) to improve the resorption rate of CPC with fiber degradation. Different weight percentages of electrospun poly(ε-caprolactone) fibers (0%, 3%, and 7%, named as ultrafine fiber-incorporated CPC0 [UFICPC0], UFICPC3, and UFICPC7) were included into preset CPC specimens for in vitro immersion in lipase phosphate-buffered solution and long-term in vivo implantation in the femoral condyle of rabbits. The effect of the ultrafine poly(ε-caprolactone) fibers with a diameter ranging from nanometer to micrometer on CPC degradation was evaluated by measuring the pH of the medium, mass loss, porosity, and physiochemical properties. For the in vivo evaluation, histomorphometrical analysis as well as three-dimensional (3D) reconstruction was applied to assess the osteogenic properties of the CPC composite. After in vitro immersion and in vivo implantation, the total porosity and macroporosity as well as the bone formation and ingrowth increased significantly during time in the fiber-incorporated CPC specimens. After 24 weeks of implantation, the degraded space was occupied by newly formed bone, and the UFICPC3 and UFICPC7 composites showed ~3.5 times higher fraction of bone volume than that of the pristine CPC (UFICPC0). In vitro and in vivo results proved that the introduction of ultrafine degradable fibers within a CPC matrix can be used to improve macroporosity efficiently and enhance CPC degradation and bone ingrowth largely. PMID:26792992

  9. Calcium phosphate cements properties with polymers addition; Propriedades do cimento de fosfato de calcio com adicao de polimeros

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, J.M.; Trajano, W.T.; Escobar, C.F.; Santos, L.A., E-mail: julianafernandes2@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil)

    2012-07-01

    Calcium phosphate cements (CPC) have attracted great interest to use in orthopedics and dentistry as replacements for damaged parts of the skeletal system, showing good biocompatibility and osseointegration, allowing its use as bone graft. Several studies have shown that the addition of polymer additives have a strong influence on the cement properties. The low mechanical strength is the main obstacle to greater use of CPC as an implant material. The objective of this study was to evaluate properties of a cement based on α-tricalcium phosphate (α-TCP), added polymers. PVA (10%, 8%, 6%), sodium alginate (2%) and polyacrylate ammonia (3%), all in weight, were added to the synthesized α-TCP powder. The samples were molded and evaluated for density, porosity in vitro test (Simulated Body Fluid), crystalline phases and mechanical strength. The results show increased the mechanical properties of the cement when added these polymers.

  10. Bone mineralisation in premature infants cannot be predicted from serum alkaline phosphatase or serum phosphate

    OpenAIRE

    Faerk, J; Peitersen, B; Petersen, S; Michaelsen, K

    2002-01-01

    Background: The bone mineral content of premature infants at term is lower than in mature infants at the same postconceptional age. Serum alkaline phosphatase and serum phosphate are often used as indicators of bone mineralisation.

  11. Pathogenic role of basic calcium phosphate crystals in destructive arthropathies.

    Directory of Open Access Journals (Sweden)

    Hang-Korng Ea

    Full Text Available basic calcium phosphate (BCP crystals are commonly found in osteoarthritis (OA and are associated with cartilage destruction. BCP crystals induce in vitro catabolic responses with the production of metalloproteases and inflammatory cytokines such as interleukin-1 (IL-1. In vivo, IL-1 production induced by BCP crystals is both dependant and independent of NLRP3 inflammasome. We aimed to clarify 1/ the role of BCP crystals in cartilage destruction and 2/ the role of IL-1 and NLRP3 inflammasome in cartilage degradation related to BCP crystals.synovial membranes isolated from OA knees were analysed by alizarin Red and FTIR. Pyrogen free BCP crystals were injected into right knees of WT, NLRP3 -/-, ASC -/-, IL-1α -/- and IL-1β-/- mice and PBS was injected into left knees. To assess the role of IL-1, WT mice were treated by intra-peritoneal injections of anakinra, the IL-1Ra recombinant protein, or PBS. Articular destruction was studied at d4, d17 and d30 assessing synovial inflammation, proteoglycan loss and chondrocyte apoptosis. BCP crystals were frequently found in OA synovial membranes including low grade OA. BCP crystals injected into murine knee joints provoked synovial inflammation characterized by synovial macrophage infiltration that persisted at day 30, cartilage degradation as evidenced by loss of proteoglycan staining by Safranin-O and concomitant expression of VDIPEN epitopes, and increased chondrocyte apoptosis. BCP crystal-induced synovitis was totally independent of IL-1α and IL-1β signalling and no alterations of inflammation were observed in mice deficient for components of the NLRP3-inflammasome, IL-1α or IL-1β. Similarly, treatment with anakinra did not prevent BCP crystal effects. In vitro, BCP crystals elicited enhanced transcription of matrix degrading and pro-inflammatory genes in macrophages.intra-articular BCP crystals can elicit synovial inflammation and cartilage degradation suggesting that BCP crystals have a direct

  12. Calcium phosphate/porous silicon biocomposites prepared by cyclic deposition methods: Spin coating vs electrochemical activation

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Montelongo, J., E-mail: jacobo.hernandez@uam.es [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Gallach, D.; Naveas, N.; Torres-Costa, V. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Climent-Font, A. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Centro de Microanálisis de Materiales (CMAM), Universidad Autónoma de Madrid, Madrid 28049 (Spain); García-Ruiz, J.P. [Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, Madrid 28049 (Spain); Manso-Silvan, M. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2014-01-01

    Porous silicon (PSi) provides an excellent platform for bioengineering applications due to its biocompatibility, biodegradability, and bioresorbability. However, to promote its application as bone engineering scaffold, deposition of calcium phosphate (CaP) ceramics in its hydroxyapatite (HAP) phase is in progress. In that sense, this work focuses on the synthesis of CaP/PSi composites by means of two different techniques for CaP deposition on PSi: Cyclic Spin Coating (CSC) and Cyclic Electrochemical Activation (CEA). Both techniques CSC and CEA consisted on alternate Ca and P deposition steps on PSi. Each technique produced specific morphologies and CaP phases using the same independent Ca and P stem-solutions at neutral pH and at room temperature. The brushite (BRU) phase was favored with the CSC technique and the hydroxyapatite (HAP) phase was better synthesized using the CEA technique. Analyses by elastic backscattering spectroscopy (EBS) on CaP/PSi structures synthesized by CEA supported that, by controlling the CEA parameters, an HAP coating with the required Ca/P atomic ratio of 1.67 can be promoted. Biocompatibility was evaluated by bone-derived progenitor cells, which grew onto CaP/PSi prepared by CSC technique with a long-shaped actin cytoskeleton. The density of adhered cells was higher on CaP/PSi prepared by CEA, where cells presented a normal morphological appearance and active mitosis. These results can be used for the design and optimization of CaP/PSi composites with enhanced biocompatibility for bone-tissue engineering. - Highlights: • Proposed cyclic methods produce specific morphologies and CaP phases in biocomposites. • The brushite phase is favored in the biocomposite produced by Cyclic Spin Coating. • The hydroxyapatite phase is favored in the biocomposite produced by Cyclic Electrochemical Activation. • The Ca/P atomic ratio of hydroxyapatite was validated by elastic backscattering spectroscopy. • Cells grown showed morphological and

  13. Induced Pluripotent Stem Cell-derived Mesenchymal Stem Cell Seeding on Biofunctionalized Calcium Phosphate Cements

    Institute of Scientific and Technical Information of China (English)

    WahWah TheinHan; Jun Liu; Minghui Tang; Wenchuan Chen; Linzhao Cheng; Hockin H. K. Xu

    2013-01-01

    Induced pluripotent stem cells (iPSCs) have great potential due to their proliferation and differentiation capability. The objectives of this study were to generate iPSC-derived mesenchymal stem cells (iPSC-MSCs), and investigate iPSC-MSC proliferation and osteogenic differentiation on calcium phosphate cement (CPC) containing biofunctional agents for the first time. Human iPSCs were derived from marrow CD34+ cells which were reprogrammed by a single episomal vector. iPSCs were cultured to form embryoid bodies (EBs), and MSCs migrated out of EBs. Five biofunctional agents were incorporated into CPC:RGD (Arg-Gly-Asp) peptides, fibronectin (Fn), fibronectin-like engineered polymer protein (FEPP), extracellular matrix Geltrex, and platelet concentrate. iPSC-MSCs were seeded on five biofunctionalized CPCs:CPC-RGD, CPC-Fn, CPC-FEPP, CPC-Geltrex, and CPC-Platelets. iPSC-MSCs on biofunctional CPCs had enhanced proliferation, actin fiber expression, osteogenic differentiation and mineralization, compared to control. Cell proliferation was greatly increased on biofunctional CPCs. iPSC-MSCs underwent osteogenic differentiation with increased alkaline phosphatase, Runx2 and collagen-I expressions. Mineral synthesis by iPSC-MSCs on CPC-Platelets was 3-fold that of CPC control. In conclusion, iPSCs showed high potential for bone engineering. iPSC-MSCs on biofunctionalized CPCs had cell proliferation and bone mineralization that were much better than traditional CPC. iPSC-MSC-CPC constructs are promising to promote bone regeneration in craniofacial/orthopedic repairs.

  14. 丝素蛋白增强型磷酸钙复合rhBMP-2用于绵羊腰椎椎体间融合的实验研究%Experimental study on lumbar interbody fusion with silk fibroin enhanced calcium phosphate cement composite loaded with recombinant human bone morphogenetic protein-2 in sheep

    Institute of Scientific and Technical Information of China (English)

    陈亮; 顾勇; 陈晓庆; 干旻峰; 朱雪松; 杨惠林; 唐天驷

    2010-01-01

    Objective To evaluate the osteogenic characteristics of an injectable silk fibroin (SF) enhanced calcium phosphate cement (CPC) composite loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2) on lumbar interbody fusion in sheep. Methods Twenty-four mature sheep were randomly divided into two groups. Each sheep underwent L1.2, L3.4 and L5.6 lumber interbody fusion, and the three disc spaces were randomly implanted with three of the following materials: SF/CPC, CPC/rhBMP-2, SF/CPC/rhBMP2 and autogenous iliac crest bone. One group was killed at 6 months and the other at 12 months. The fusion segments were observed and analyzed by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. Results The fusion rates of SF/CPC, CPC/rhBMP-2, SF/CPC/rhBMP-2 and autogenous bone assessed by manual palpation were 0, 33.33%, 55.56% and 77.78% respectively at 6 months. At 12 months, the fusion rates improved to 11.11%, 44.44%, 77.78% and 77.78%, respectively.The biomechanical results showed that fusion stiffness was significantly greater in autograft compared with SF/CPC/rhBMP-2, CPC/rhBMP-2, and SF/CPC in 4 degrees of freedom (flexion, extension, right bending, and left bending) at 6 months. The SF/CPC/rhBMP-2 composite showed similar stiffness as autograft, which was significantly greater than CPC/rhBMP-2 and SF/CPC at 12 nonths. Both CPC/rhBMP-2 and SF/CPC/rhBMP-2 showed significantly greater stiffness at 12 months compared with that of at 6 months. The results showed that bone volume was significantly greater in autograft compared with SF/CPC/rhBMP-2, CPC/rhBMP-2, and SF/CPC at 6 months. There was significant difference among ceramic residue among SF/CPC, CPC/rhBMP-2 and SF/CPC/rhBMP-2, with SF/CPC the greatest and SF/CPC/thBMP-2 the least. At 12 months, the bone volume of SF/CPC/rhBMP-2 composite was comparable with autograft, and greater than that of CPC/rhBMP-2 and SF/CPC. The bone volume of SF/CPC, CPC

  15. Templating route for mesostructured calcium phosphates with carboxylic acid- and amine-type surfactants.

    Science.gov (United States)

    Ikawa, Nobuaki; Hori, Hideki; Kimura, Tatsuo; Oumi, Yasunori; Sano, Tsuneji

    2008-11-18

    Mesostructured calcium phosphates constructed by ionic frameworks were synthesized using carboxylic acid- and amine-type surfactants in mixed solvent systems of ethanol and water. A lamellar mesostructured calcium phosphate was prepared using palmitic acid as an anionic surfactant, as in the case using n-alkylamines. A wormhole-like mesostructured calcium phosphate can be obtained using dicarboxyl N-lauroyl- l-glutamic acid, whose headgroup is larger than that of palmitic acid. Similar mesostructured product was obtained using 4-dodecyldiethylenetriamine with a large headgroup containing two primary amine groups. Interactions of carboxyl and primary amino groups in the surfactant molecules with inorganic species are quite important for the formation of mesostructured calcium phosphates. The Ca/P molar ratio of mesostructured calcium phosphates was strongly affected by the molecular structure of surfactants containing carboxyl and primary amino groups. Ca-rich materials can be obtained using carboxylic acid-type surfactants (Ca/P approximately 1.7) rather than amine-type surfactants (Ca/P approximately 1.0). PMID:18947246

  16. Minimally Invasive Pedicle Screw Fixation Combined with Vertebroplasty with Calcium Phosphate Bone Cement in the Treatment of Thoracolumbar Burst Fracture%微创椎弓根钉内固定联合磷酸钙骨水泥椎体成形术治疗胸腰椎爆裂性骨折

    Institute of Scientific and Technical Information of China (English)

    顾宇彤; 梁朝革; 张亮; 林红; 周健

    2015-01-01

    目的:评估微创椎弓根钉内固定(微小切口非空心椎弓根钉技术)联合磷酸钙骨水泥经皮穿刺椎体成形术(percutaneous vertebroplasty ,PVP)治疗胸腰椎爆裂性骨折的疗性和安全性。方法:采用微创椎弓根钉内固定联合磷酸钙骨水泥 PVP术治疗23例单节段胸腰椎新鲜爆裂性骨折且无神经症状的患者,伤椎位于 T11~L2,均属A3型骨折。记录手术时间、术中出血量、骨水泥注射量和住院天数。记录术前及术后即刻、1个月、2个月、3个月、6个月、1年、2年的腰背痛评分,计算并比较各时点的椎体高度压缩率、恢复率、椎体后凸角、椎体后凸矫正率。结果:磷酸钙骨水泥平均注射量为4.9(3.8~6.4)mL,平均手术时间92(75~120) min ,平均出血量52(40~75) mL ,平均住院5.6(4~7) d ,术后平均随访26(24~29)个月。VAS评分由术前的(8.8±1.2)分下降至术后即刻的(1.8±0.6)分及术后2年的(0.4±0.5)分,差异均有显著统计学意义(P<0.001)。高度压缩率由术前的(50.4±7.2)%显著下降至术后即刻的(6.2±1.5)%及术后2年的(6.9±1.4)%,差异均有显著统计学意义(P<0.001)。后凸角由术前的(22.6±1.8)°下降至术后即刻的(3.2±1.7)°及术后2年的(5.1±1.5)°,差异均有显著统计学意义( P<0.001)。随访过程中术后高度恢复率、后凸矫正率无明显减小;未出现螺钉松动、断钉或断棒。结论:微创椎弓根钉内固定联合磷酸钙骨水泥PV P术是治疗胸腰椎爆裂性骨折的安全、有效的方法。%Objective:To evaluate the efficacy and safety of minimally invasive pedicle screw fixation combined with percutaneous vertebroplasty(PVP) with calcium phosphate bone cement in the treatment of acute thoracolumbar burst fracture . Methods:Twenty‐three patients

  17. Regulatory inhibition of biological tissue mineralization by calcium phosphate through post-nucleation shielding by fetuin-A

    Science.gov (United States)

    Chang, Joshua C.; Miura, Robert M.

    2016-04-01

    In vertebrates, insufficient availability of calcium and inorganic phosphate ions in extracellular fluids leads to loss of bone density and neuronal hyper-excitability. To counteract this problem, calcium ions are usually present at high concentrations throughout bodily fluids—at concentrations exceeding the saturation point. This condition leads to the opposite situation where unwanted mineral sedimentation may occur. Remarkably, ectopic or out-of-place sedimentation into soft tissues is rare, in spite of the thermodynamic driving factors. This fortunate fact is due to the presence of auto-regulatory proteins that are found in abundance in bodily fluids. Yet, many important inflammatory disorders such as atherosclerosis and osteoarthritis are associated with this undesired calcification. Hence, it is important to gain an understanding of the regulatory process and the conditions under which it can go awry. In this manuscript, we extend mean-field continuum classical nucleation theory of the growth of clusters to encompass surface shielding. We use this formulation to study the regulation of sedimentation of calcium phosphate salts in biological tissues through the mechanism of post-nuclear shielding of nascent mineral particles by binding proteins. We develop a mathematical description of this phenomenon using a countable system of hyperbolic partial differential equations. A critical concentration of regulatory protein is identified as a function of the physical parameters that describe the system.

  18. Regulatory inhibition of biological tissue mineralization by calcium phosphate through post-nucleation shielding by fetuin-A.

    Science.gov (United States)

    Chang, Joshua C; Miura, Robert M

    2016-04-21

    In vertebrates, insufficient availability of calcium and inorganic phosphate ions in extracellular fluids leads to loss of bone density and neuronal hyper-excitability. To counteract this problem, calcium ions are usually present at high concentrations throughout bodily fluids-at concentrations exceeding the saturation point. This condition leads to the opposite situation where unwanted mineral sedimentation may occur. Remarkably, ectopic or out-of-place sedimentation into soft tissues is rare, in spite of the thermodynamic driving factors. This fortunate fact is due to the presence of auto-regulatory proteins that are found in abundance in bodily fluids. Yet, many important inflammatory disorders such as atherosclerosis and osteoarthritis are associated with this undesired calcification. Hence, it is important to gain an understanding of the regulatory process and the conditions under which it can go awry. In this manuscript, we extend mean-field continuum classical nucleationtheory of the growth of clusters to encompass surface shielding. We use this formulation to study the regulation of sedimentation of calcium phosphate salts in biological tissues through the mechanism of post-nuclear shielding of nascent mineral particles by binding proteins. We develop a mathematical description of this phenomenon using a countable system of hyperbolic partial differential equations. A critical concentration of regulatory protein is identified as a function of the physical parameters that describe the system. PMID:27389239

  19. Preparation and mechanical property of core-shell type chitosan/calcium phosphate composite fiber

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Atsushi [Japan Society for the Promotion of Science, Ikenohata1-1-1, Daitou-ku, Tokyo 110-0008 (Japan) and Creative Research Initiative ' Sousei' , Hokkaido University, Sapporo, Hokkaido 001-0021 (Japan)]. E-mail: MATSUDA.Atsushi@nims.go.jp; Ikoma, Toshiyuki [Biomaterials Research Center, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan); Kobayashi, Hisatoshi [Biomaterials Research Center, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)]. E-mail: Kobayashi.Hisatoshi@nims.go.jp; Tanaka, Junzo [Creative Research Initiative ' Sousei' , Hokkaido University, Sapporo, Hokkaido 001-0021 (Japan); Biomaterials Research Center, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)

    2004-12-01

    Core-shell type chitosan/calcium phosphate composite fibers were prepared by a facile wet spinning method; the chitosan aqueous solution with PO{sub 4} ions was dropped and coagulated in the ethanol/calcium hydroxide solutions at different mixed ratio. X-ray diffraction (XRD) patterns indicated that the crystal phases of calcium phosphates in the composite fibers were a low-crystalline hydroxyapatite (HAp; Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2})or the low-crystalline hydroxyapatite/brushite mixture depended on the ratio of ethanol/calcium hydroxide solutions. The inorganic contents were ca. 60 wt.% by using the TG-DTA analysis. The energy-dispersive X-ray spectroscopy (EDS) analysis indicated that Ca and P atoms were mainly distributed on the outer layer of the composite fiber to grow calcium phosphate crystals; however, a little amount of P atom still remained at the inside of the fiber. This indicated that the composite fibers formed a unique core-shell structure with shell of calcium phosphate and core of chitosan. The mechanical property of the fibers was reinforced by the initial concentration of chitosan solution.

  20. Conditional Deletion of Fgfr1 in the Proximal and Distal Tubule Identifies Distinct Roles in Phosphate and Calcium Transport.

    Directory of Open Access Journals (Sweden)

    Xiaobin Han

    Full Text Available A postnatal role of fibroblast growth factor receptor-1 (FGFR1 in the kidney is suggested by its binding to α-Klotho to form an obligate receptor for the hormone fibroblast growth factor-23 (FGF-23. FGFR1 is expressed in both the proximal and distal renal tubular segments, but its tubular specific functions are unclear. In this study, we crossed Fgfr1flox/flox mice with either gamma-glutamyltransferase-Cre (γGT-Cre or kidney specific-Cre (Ksp-Cre mice to selectively create proximal tubule (PT and distal tubule (DT Fgfr1 conditional knockout mice (designated Fgfr1PT-cKO and Fgfr1DT-cKO, respectively. Fgfr1PT-cKO mice exhibited an increase in sodium-dependent phosphate co-transporter expression, hyperphosphatemia, and refractoriness to the phosphaturic actions of FGF-23, consistent with a direct role of FGFR1 in mediating the proximal tubular phosphate responses to FGF-23. In contrast, Fgfr1DT-cKO mice unexpectedly developed hypercalciuria, secondary elevations of parathyroid hormone (PTH, hypophosphatemia and enhanced urinary phosphate excretion. Fgfr1PT-cKO mice also developed a curly tail/spina bifida-like skeletal phenotype, whereas Fgfr1DT-cKO mice developed renal tubular micro-calcifications and reductions in cortical bone thickness. Thus, FGFR1 has dual functions to directly regulate proximal and distal tubule phosphate and calcium reabsorption, indicating a physiological role of FGFR1 signaling in both phosphate and calcium homeostasis.

  1. Conjugated linoleic acid and calcium co-supplementation improves bone health in ovariectomised mice

    OpenAIRE

    Park, Yooheon; Kim, Jonggun; Scrimgeour, Angus G.; Condlin, Michelle L.; Kim, Daeyoung; Park, Yeonhwa

    2013-01-01

    Osteoporosis is a significant health concern for the elderly; conjugated linoleic acid (CLA) has been shown to improve overall bone mass when calcium is included as a co-supplement. However, potential effects of CLA and calcium on bone mass during a period of bone loss have not been reported. The purpose of this study was to determine how dietary calcium modulates the effects of conjugated linoleic acid (CLA) in preventing bone loss, using an ovariectomised mouse model. CLA supplementation si...

  2. Silver-doped calcium phosphate nanoparticles: synthesis, characterization, and toxic effects toward mammalian and prokaryotic cells.

    Science.gov (United States)

    Peetsch, Alexander; Greulich, Christina; Braun, Dieter; Stroetges, Christian; Rehage, Heinz; Siebers, Bettina; Köller, Manfred; Epple, Matthias

    2013-02-01

    Spherical silver-doped calcium phosphate nanoparticles were synthesized in a co-precipitation route from calcium nitrate/silver nitrate and ammonium phosphate in a continuous process and colloidally stabilized by carboxymethyl cellulose. Nanoparticles with 0.39 wt% silver content and a diameter of about 50-60 nm were obtained. The toxic effects toward mammalian and prokaryotic cells were determined by viability tests and determination of the minimal inhibitory and minimal bactericidal concentrations (MIC and MBC). Three mammalian cells lines, i.e. human mesenchymal stem cells (hMSC) and blood peripheral mononuclear cells (PBMC, monocytes and T-lymphocytes), and two prokaryotic strains, i.e. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used. Silver-doped calcium phosphate nanoparticles and silver acetate showed similar effect toward mammalian and prokaryotic cells with toxic silver concentrations in the range of 1-3 μg mL(-1).

  3. Phosphate recovery using calcium zeolite in ultrafiltration pilot plant

    OpenAIRE

    La Rotonda Ferrer, Pablo

    2015-01-01

    One of the most important ecological problems is the eutrophication, this process consist in the uncontrolled growing of algae and phytoplankton, which can destroy entire aquatic ecosystems. The reason of this process is the excess of nutrients, as for example, phosphate coming from human activities. This project focus on the study of synthetic zeolites capacity to absorb phosphate from wastewater. Zeolites are porous minerals of the alumina-silicates family with high capacity ...

  4. The effects of hydroxyapatite/calcium phosphate glass scaffold and its surface modification with bovine serum albumin on 1-wall intrabony defects of beagle dogs: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Um, Yoo-Jung; Jung, Ui-Won; Chae, Gyung-Joon; Kim, Chang-Sung; Cho, Kyoo-Sung; Kim, Chong-Kwan; Choi, Seong-Ho [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752 l (Korea, Republic of); Lee, Yong-Keun [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-750 (Korea, Republic of)], E-mail: shchoi726@yuhs.ac

    2008-12-15

    The purpose of this study was to evaluate the effects of biphasic hydroxyapatite/calcium phosphate glass (HA/CPG) scaffold and its surface modification with bovine serum albumin (BSA) on periodontal regeneration. 1-wall intrabony defects were surgically created on five beagle dogs. HA/CPG scaffolds, with a hydroxyapatite (HA)/calcium phosphate glass (CPG) ratio of 95:5 by weight (%) and surface modification done by 2% bovine serum albumin, were used. The control group received surgical flap operation, and the experimental groups were filled with HA/CPG scaffolds and HA/CPG(BSA) scaffolds. The animals were sacrificed eight weeks after surgery. Histological findings revealed better space maintenance in the experimental groups than the control group, and showed new bone formation intermittently in between the residual material particles. The newly formed bone was mostly woven bone and the residual particles were undergoing resorption. Cementum regeneration was observed with limited root resorption in all the groups. Histometric analysis also revealed greater mean values in new bone formation, cementum regeneration and bone area than the control group in both experimental groups. However, similar findings were presented between HA/CPG and HA/CPG(BSA). The result of the present study revealed the newly fabricated HA/CPG scaffold to have a potential use as a bone substitute material.

  5. In vitro elution of vancomycin from biodegradable osteoconductive calcium phosphate-polycaprolactone composite beads for treatment of osteomyelitis.

    Science.gov (United States)

    Makarov, C; Cohen, V; Raz-Pasteur, A; Gotman, I

    2014-10-01

    In this work, osteoconductive composite materials comprising a large volume fraction of a bioresorbable calcium phosphate ceramic (CaP) and a smaller amount of a polycaprolactone polymer (PCL) were studied as a degradable antibiotic carrier material for treatment of osteomyelitis. Beads loaded with 1 and 4wt.% vancomycin were prepared by admixing dissolved drug to an in situ synthesized dicalcium phosphate (DCP)-PCL or solution-mixed beta-tricalcium phosphate (βTCP)-PCL composite powder followed by high pressure consolidation of the blend at room temperature. Vancomycin release was measured in phosphate-buffered saline (PBS) at 37°C. All the beads gradually released the drug over the period of 4-11weeks, depending on the composite matrix homogeneity and porosity. Mathematical modeling using the Peppas equation showed that vancomycin elution was diffusion controlled. The stability of the antibiotic after high pressure application at room temperature was demonstrated by high-performance liquid chromatography-mass spectrometry (HPLC-MS) studies and MIC testing. The preservation of the structure and activity of vancomycin during the processing of composite beads and its sustained in vitro release profile suggest that high pressure consolidated CaP-PCL beads may be useful in the treatment of chronic bone infections as resorbable delivery vehicles of vancomycin and even of thermally unstable drug substances.

  6. Phosphate-induced metal stabilization: Use of apatite and bone char for the removal of soluble radionuclides in authentic and simulated DOE groundwater

    International Nuclear Information System (INIS)

    The apatite group of minerals is a family of calcium phosphate phases. Apatite is the principal component of bone tissue, and it also occurs naturally as mineral deposits in the geosphere. Bone char is calcined (coked) animal bone, containing activated carbon as well as calcium phosphate mineral phases. Apatite IItrademark is a more reactive form of apatite, supplied by UFA Ventures, Inc., at a cost of approximately 1/4 that of commercial bone char. Apatite is shown to be effective for the removal of select heavy metal impurities in groundwater. Previous investigations have demonstrated that apatite is an effective medium for the stabilization of soluble lead, cadmium, and zinc from mine waste leachate by the formation of highly insoluble precipitate phases. The performance of bone char and apatite II are compared with other candidate sorption media (including granular activated carbon and anion exchange resin) for the removal of soluble uranyl ion in synthetic DOE Site groundwater supplemented with varying levels of interfering nitrate ion. Apatite II has a greater affinity for U(VI), especially in the presence of nitrate ion, as evidenced by a larger value for the conditional distribution coefficient (Kd) in batch test experiments. Contact of uranyl nitrate solution with apatite II is shown to produce highly insoluble mineral phases of the autunite group (calcium uranyl phosphate hydrates). Apatite II is also demonstrated to be moderately effective for the removal of soluble radioactive isotopes of strontium, but not cesium, when these ions are supplemented into authentic DOE Site groundwater

  7. Mixed zirconia calcium phosphate coatings for dental implants: tailoring coating stability and bioactivity potential.

    Science.gov (United States)

    Pardun, Karoline; Treccani, Laura; Volkmann, Eike; Streckbein, Philipp; Heiss, Christian; Li Destri, Giovanni; Marletta, Giovanni; Rezwan, Kurosch

    2015-03-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. PMID:25579931

  8. Microwave assisted synthesis and characterization of magnesium substituted calcium phosphate bioceramics

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Nida Iqbal [Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, M. A. Jinnah Campus, Defence Road, Off Raiwind Road, Lahore (Pakistan); Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Ijaz, Kashif; Zahid, Muniza; Khan, Abdul S. [Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, M. A. Jinnah Campus, Defence Road, Off Raiwind Road, Lahore (Pakistan); Abdul Kadir, Mohammed Rafiq [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Hussain, Rafaqat [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johore (Malaysia); Anis-ur-Rehman [Department of Physics, COMSATS Institute of Information Technology, Chakshahzad Campus, Islamabad (Pakistan); Darr, Jawwad A. [Clean Materials Technology Group, Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Ihtesham-ur-Rehman [The Kroto Research Institute, North Campus, University of Sheffield, Broad Lane, Sheffield S3 7HQ (United Kingdom); Chaudhry, Aqif A., E-mail: aqifanwar@ciitlahore.edu.pk [Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, M. A. Jinnah Campus, Defence Road, Off Raiwind Road, Lahore (Pakistan)

    2015-11-01

    Hydroxyapatite is used extensively in hard tissue repair due to its biocompatibility and similarity to biological apatite, the mineral component of bone. It differs subtly in composition from biological apatite which contains other ions such as magnesium, zinc, carbonate and silicon (believed to play biological roles). Traditional methods of hydroxyapatite synthesis are time consuming and require strict reaction parameter control. This paper outlines synthesis of magnesium substituted hydroxyapatite using simple microwave irradiation of precipitated suspensions. Microwave irradiation resulted in a drastic decrease in ageing times of amorphous apatitic phases. Time taken to synthesize hydroxyapatite (which remained stable upon heat treatment at 900 °C for 1 h) reduced twelve folds (to 2 h) as compared to traditionally required times. The effects of increasing magnesium concentration in the precursors on particle size, surface area, phase-purity, agglomeration and thermal stability, were observed using scanning electron microscopy, BET surface area analysis, X-ray diffraction and photo acoustic Fourier transform infra-red spectroscopy. Porous agglomerates were obtained after a brief heat-treatment (1 h) at 900 °C. - Highlights: • Microwave irradiation of suspensions of calcium phosphates accelerated maturation. • Reactions took 2 h to complete as compared to 18 h required traditionally. • Magnesium contents higher than 1 wt.% lead to the presence of non-apatitic phases. • Agglomerates with micron and sub-micron porosity were obtained after heat-treatment.

  9. Biological influence of Ca/P ratio on calcium phosphate coatings by sol-gel processing.

    Science.gov (United States)

    Catauro, M; Papale, F; Sapio, L; Naviglio, S

    2016-08-01

    The objective of this work has been to develop low temperature sol-gel glass coatings to modify the substrate surface and to evaluate their bioactivity and biocompatibility. Glasses, based on SiO2·CaO·P2O5, were synthesized by the sol-gel technique using tetraethyl orthosilicate, calcium nitrate tetrahydrate and triethyl phosphate as precursors of SiO2, CaO and P2O5, respectively. Those materials, still in the sol phase, have been used to coat substrates by means of the dip-coating technique. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) has been used for characterize coatings and a microstructural analysis has been obtained using scanning electron microscopy (SEM). The potential applications of the coatings in the biomedical field were evaluated by bioactivity and biocompatibility tests. The coated substrate was immersed in simulated body fluid (SBF) for 21days and the hydroxyapatite deposition on its surface was subsequently evaluated via SEM-EDXS analysis, as an index of bone-bonding capability. In order to study the cell behavior and response to our silica based materials, prepared via the sol-gel method, with various Ca/P ratio and coating substrate, we have used the human osteoblast-like U2OS cell line.

  10. Microwave assisted synthesis and characterization of magnesium substituted calcium phosphate bioceramics

    International Nuclear Information System (INIS)

    Hydroxyapatite is used extensively in hard tissue repair due to its biocompatibility and similarity to biological apatite, the mineral component of bone. It differs subtly in composition from biological apatite which contains other ions such as magnesium, zinc, carbonate and silicon (believed to play biological roles). Traditional methods of hydroxyapatite synthesis are time consuming and require strict reaction parameter control. This paper outlines synthesis of magnesium substituted hydroxyapatite using simple microwave irradiation of precipitated suspensions. Microwave irradiation resulted in a drastic decrease in ageing times of amorphous apatitic phases. Time taken to synthesize hydroxyapatite (which remained stable upon heat treatment at 900 °C for 1 h) reduced twelve folds (to 2 h) as compared to traditionally required times. The effects of increasing magnesium concentration in the precursors on particle size, surface area, phase-purity, agglomeration and thermal stability, were observed using scanning electron microscopy, BET surface area analysis, X-ray diffraction and photo acoustic Fourier transform infra-red spectroscopy. Porous agglomerates were obtained after a brief heat-treatment (1 h) at 900 °C. - Highlights: • Microwave irradiation of suspensions of calcium phosphates accelerated maturation. • Reactions took 2 h to complete as compared to 18 h required traditionally. • Magnesium contents higher than 1 wt.% lead to the presence of non-apatitic phases. • Agglomerates with micron and sub-micron porosity were obtained after heat-treatment

  11. Dysregulation of phosphate metabolism and conditions associated with phosphate toxicity

    OpenAIRE

    Brown, Ronald B; Razzaque, Mohammed S

    2015-01-01

    Phosphate homeostasis is coordinated and regulated by complex cross-organ talk through delicate hormonal networks. Parathyroid hormone (PTH), secreted in response to low serum calcium, has an important role in maintaining phosphate homeostasis by influencing renal synthesis of 1,25-dihydroxyvitamin D, thereby increasing intestinal phosphate absorption. Moreover, PTH can increase phosphate efflux from bone and contribute to renal phosphate homeostasis through phosphaturic effects. In addition,...

  12. Why Basic Calcium Phosphate Crystals Should Be Targeted In the Treatment of Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Claire-Louise Murphy

    2014-07-01

    Full Text Available Osteoarthritis (OA is the most common form of arthritis and results in significant social, psychological, and economic costs. It is characterised by progressive cartilage loss, bone remodelling, osteophyte formation, and synovial inflammation with resultant joint pain and disability. Since OA affects the entire joint, it is not surprising that there has been difficulty developing an effective targeted treatment. Treatments available for structural disease modification are limited. Current options appear to mostly reduce symptoms. Basic calcium phosphate (BCP crystals represent a potential therapeutic target in OA; they have been found in 100% of knee and hip cartilages removed at joint replacement. Intra-articular BCP crystals are associated with large joint effusions and dissolution of intra-articular structures, synovial proliferation, and marked degeneration as assessed by diagnostic imaging. While BCP deposition has been considered by many to be simply a consequence of advanced OA, there is substantial evidence to support BCP crystal deposition as an active pathogenic mediator of OA. BCP crystals exhibit a multiplicity of biologic effects in vitro including the ability to stimulate mitogenesis and prostaglandin, cytokine, and matrix metalloproteinase (MMP synthesis in a number of cell types including macrophages, synovial fibroblasts, and chondrocytes. BCP crystals also contribute to inflammation in OA through direct interaction with the innate immune system. Intra-articular BCP crystals can elicit synovial inflammation and cartilage degradation in mice in vivo . Although intra-articular BCP crystals are difficult to detect at the bedside, advances in modern technology should allow improved identification and quantitation of BCP crystals. Our article focuses on why basic calcium crystals are important in the pathogenesis of OA. There is ample evidence that BCP crystals should be explored as a therapeutic target in OA.

  13. The effects of citric acid on the hydration of calcium phosphate cement

    Institute of Scientific and Technical Information of China (English)

    DAI Hong-lian; YAN Yu-hua; WANG You-fa; LI Shi-pu

    2001-01-01

    @@ INTRODUCTION Calcium phosphate cements (CPC) overcome the practical disadvantages of blocks or granulesl can be handled as a paste and sit in situ. Their structure and composition close to that of HAP make them biocompatible materials. 2 The conventional calcium phosphate cement had some problems such as long setting time (30~60 min) and low compressive strength, etc. In our system, an α-TCP/TTCP powder mixture was mixed with water containing citric acid to control the setting time and compressive strength. In this paper, the effects of various concentration citric acid solutions on the properties of the cement are reported.

  14. Serum Proteins Stabilized Calcium Phosphate Nanoparticles and Its Effect on Bel-7402 Cells

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Hydroxyapatite has a high affinity to biological macromolecules, especially to proteins. Bovine serum proteins were extracted to be used as stablizer to prepare calcium phosphate nanoparticles. 167.7 am and87.7 nm particles were respectively prepared by using bovine serum protein fractions at the concentration of 0.5mg/mL and 1.0 mg/mL. As the polysaccharide stabilized hydroxyapatite nanoparticles, the protein-stablized nanoparticles also inhibited the proliferation rate of Bel-7402 cells. It suggested that proteins could be applied to prepare calcium phosphate nanoparticles and it also has the anticancer effect.

  15. Synthesis and characterization of porous calcium phosphate; Sintesis y caracterizacion del fosfato de calcio poroso

    Energy Technology Data Exchange (ETDEWEB)

    Granados C, F.; Serrano G, J.; Bonifacio M, J. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: fgc@nuclear.inin.mx

    2007-07-01

    The porous calcium phosphate was prepared by the continuous precipitation method using Ca(NO{sub 3}){sub 2}.4H{sub 2}O and NH{sub 4}H{sub 2}PO{sub 4} salts. The synthesized material was structurally and superficially characterized using the XRD, BET, IR TGA and SEM techniques. The obtained inorganic material was identified as calcium phosphate that presents a great specific area for what can be efficiently used as adsorbent material for adsorption studies in the radioactive wastes treatment present in aqueous solution. (Author)

  16. Casein Phosphopeptide-Amorphous Calcium Phosphate and Shear Bond Strength of Adhesives to Primary Teeth Enamel

    OpenAIRE

    Farokh Gisovar, Elham; Hedayati, Nassim; Shadman, Niloofar; Shafiee, Leila

    2015-01-01

    Background: CPP-ACP (Phosphopeptide-Amorphous Calcium Phosphate) has an important role in caries prevention in pediatric patients. This study was done, because of the great use of CPP-ACP and the need for restoration for teeth treated with CPP-ACP as well as the importance of shear bond strength of adhesives in the success of restorations. Objectives: This study aimed to evaluate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on shear bond strength of dental adhesiv...

  17. Experimental posterolateral spinal fusion with beta tricalcium phosphate ceramic and bone marrow aspirate composite graft

    OpenAIRE

    Gupta Ankit; Chauhan Vijendra; Chauhan Neena; Sharma Sansar; Maheshwari Rajesh; Agarwal Atul

    2010-01-01

    Background: Beta tricalcium phosphate is commonly used in metaphyseal defects but its use in posterolateral spinal fusion remains controversial. There are very few published animal studies in which use of beta tricalcium phosphate has been evaluated in the posterolateral lumbar arthrodesis model. Hence we conducted a study to evaluate the potential of composite graft of beta tricalcium phosphate and bone marrow aspirate in comparison to autologous bone graft, when used for posterolateral spin...

  18. Physicochemical Characterization and In Vivo Evaluation of Amorphous and Partially Crystalline Calcium Phosphate Coatings Fabricated on Ti-6Al-4V Implants by the Plasma Spray Method

    Directory of Open Access Journals (Sweden)

    Estevam A. Bonfante

    2012-01-01

    Full Text Available Objective. To characterize the topographic and chemical properties of 2 bioceramic coated plateau root form implant surfaces and evaluate their histomorphometric differences at 6 and 12 weeks in vivo. Methods. Plasma sprayed hydroxyapatite (PSHA and amorphous calcium phosphate (ACP surfaces were characterized by scanning electron microscopy (SEM, interferometry (IFM, X-ray diffraction (XRD, and Fourier transform infrared spectroscopy (FT-IR. Implants were placed in the radius epiphysis, and the right limb of dogs provided implants that remained for 6 weeks, and the left limb provided implants that remained 12 weeks in vivo. Thin sections were prepared for bone-to-implant contact (BIC and bone-area-fraction occupancy (BAFO measurements (evaluated by Friedman analysis <0.05. Results. Significantly, higher Sa (<0.03 and Sq (<0.02 were observed for ACP relative to PSHA. Chemical analysis revealed significantly higher HA, calcium phosphate, and calcium pyrophosphate for the PSHA surface. BIC and BAFO measurements showed no differences between surfaces. Lamellar bone formation in close contact with implant surfaces and within the healing chambers was observed for both groups. Conclusion. Given topographical and chemical differences between PSHA and ACP surfaces, bone morphology and histomorphometric evaluated parameters showed that both surfaces were osseoconductive in plateau root form implants.

  19. Effects of Astragalus membranaceus with supplemental calcium on bone mineral density and bone metabolism in calcium-deficient ovariectomized rats.

    Science.gov (United States)

    Kang, Se-Chan; Kim, Hee Jung; Kim, Mi-Hyun

    2013-01-01

    It has been reported that Astragalus membranaceus, an Asian traditional herb, has an estrogenic effect in vitro. To examine the possible role of A. membranaceus extract with supplemental calcium (Ca) on bone status in calcium-deficient (LCa) ovariectomized (OVX) rats, a total of 48 female rats were divided into six groups: (1) normal control, (2) sham operation with LCa (sham-LCa), (3) OVX with LCa (OVX-LCa), (4) A. membranaceus supplementation with OVX-LCa (OVX-MLCa), (5) Ca supplementation with OVX (OVX-Ca), and (6) A. membranaceus and Ca supplementation with OVX (OVX-MCa). A. membranaceus ethanol extract (500 mg/kg BW) and/or Ca (800 mg/kg BW) were administered orally for 8 weeks along with a Ca-deficient diet. Results revealed that Ca supplementation with or without A. membranaceus extract significantly improved bone mineral density, biomechanical strength, and ash weight of the femur and tibia in OVX rats. High Ca with A. membranaceus combination supplementation significantly increased the ash weight of the femur and tibia and decreased urinary Ca excretion compared with supplementation of Ca alone. Uterine weight was not changed by A. membranaceus administration in OVX rats. These results suggest that A. membranaceus extract combined with supplemental Ca may be more protective against the Ca loss of bone than A. membranaceus or supplementation of Ca alone in calcium-insufficient postmenopausal women.

  20. Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites

    International Nuclear Information System (INIS)

    As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg+2 and Ca+2 ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg+2 and Ca+2 ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg+2, calcium magnesium phosphates (CMPs) which release Mg+2 and Ca+2, and hydroxyapatites (HAs) which release Ca+2 were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7 days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg+2 and Ca+2 ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts. - Highlights: • Role of Mg2+ and Ca2+ ions in proliferation, and differentiation of

  1. In vivo resorption behavior of a high strength injectable calcium-phosphate cement

    Energy Technology Data Exchange (ETDEWEB)

    Wolke, J.G.C.; Ooms, E.M.; Jansen, J.A. [Univ. Medical Center, Nijmegen (Netherlands). Dept. Biomaterials

    2001-07-01

    A high strength calcium-phosphate-cement powder was prepared from a composition comprising of {alpha}-TCP, CaHPO{sub 4} (monetite), CaCO{sub 3} and some seeds of precipitated apatite. An aqueous solution of 4% Na{sub 2}HPO{sub 4} was used as liquid to start the setting reaction. The powder was mixed with cement liquid in three different liquid/powder ratios respectively 0.3, 0.35 and 0.4. Observation of the setting reaction versus time revealed that the maximum of compressive strength was achieved after 3 days reaching the value of 81 MPa. The X-ray diffraction pattern of the Ca-P cement measured 3 days after mixing and storage in Ringer's solution at 37 C showed that the {alpha}-TCP was transformed to hydroxylapatite with superposition of the peaks for monetite. XRD showed that after eight weeks of implantation the monetite peaks had disappeared. Further, the clinical handling properties of all three types of Ca-P cement appeared to be excellent. No problems in setting time or cavity filling were met during the application. The histological evaluation after two weeks of implantation showed abundant bone apposition on the cement surface without inflammatory reaction. At later time points the Ca-P cements were totally covered by a thin layer of bone and osteoclast-like cells in remodeling lacunae at the interface were resorbing the cement. At all implantation periods the PMMA controls showed the presence of a thin fibrous membrane. (orig.)

  2. Directed osteogenic differentiation of human mesenchymal stem/precursor cells on silicate substituted calcium phosphate.

    Science.gov (United States)

    Cameron, Kate; Travers, Paul; Chander, Chaman; Buckland, Tom; Campion, Charlie; Noble, Brendon

    2013-01-01

    Insufficient, underactive, or inappropriate osteoblast function results in serious clinical conditions such as osteoporosis, osteogenesis imperfecta and fracture nonunion and therefore the control of osteogenesis is a medical priority. In vitro mesenchymal stem cells (MSCs) can be directed to form osteoblasts through the addition of soluble factors such as β-glycerophosphate, ascorbic acid, and dexamethasone; however this is unlikely to be practical in the clinical setting. An alternative approach would be to use a scaffold or matrix engineered to provide cues for differentiation without the need for soluble factors. Here we describe studies using Silicate-substituted calcium phosphate (Si-CaP) and unmodified hydroxyapatite (HA) to test whether these materials are capable of promoting osteogenic differentiation of MSCs in the absence of soluble factors. Si-CaP supported attachment and proliferation of MSCs and induced osteogenesis to a greater extent than HA, as evidenced through upregulation of the osteoblast-related genes: Runx2 (1.2 fold), Col1a1 (2 fold), Pth1r (1.5 fold), and Bglap (1.7 fold) Dmp1 (1.1 fold), respectively. Osteogenic-associated proteins, alkaline phosphatase (1.4 fold), RUNX2, COL1A1, and BGLAP, were also upregulated and there was an increased production of mineralized bone matrix (1.75 fold), as detected by the Von Kossa Assay. These data indicate that inorganic substrates are capable of directing the differentiation programme of stem cells in the absence of known chemical drivers and therefore may provide the basis for bone repair in the clinical setting.

  3. Vascularization of plastic calcium phosphate cement in vivo induced by in-situ-generated hollow channels.

    Science.gov (United States)

    Yu, Tao; Dong, Chao; Shen, Zhonghua; Chen, Yan; Yu, Bo; Shi, Haishan; Zhou, Changren; Ye, Jiandong

    2016-11-01

    Despite calcium phosphate cement (CPC) is promising for bone repair therapy, slow biodegradation and insufficient vascularization in constructs negatively impacts its clinical application. A self-setting CPC composited with gelatin fiber is investigated to test the utility of this tissue engineering strategy to support rapid and extensive vascularization process. The interconnected hollow channels in CPC are formed after dissolution of gelatin fibers in vivo. The CPC-gelatin samples exhibit relatively decent/enhanced mechanical property, compared to the control. When implanted in vivo, the pre-established vascular networks in material anastomose with host vessels and accelerate vascular infiltration throughout the whole tissue construct. Different channel sizes induce different vascularization behaviors in vivo. Results indicate that the channel with the size of 250μm increases the expression of the representative angiogenic factors HIF1α, PLGF and migration factor CXCR4, which benefit the formation of small vessels. On the other hand, the channel with the size of 500μm enhances VEGF-A expression, which benefit the development of large vessels. Notably, the intersection area of channels has high invasive, sprouting and vasculogenesis potential under hypoxic condition, because more HIF1α-positive cells are observed there. Observation of the CD31-positive lumen in the border of scaffold indicates the ingrowth of blood vessels from its host into material through channel, benefited from gradually increased HIF1α expression. This kind of material was suggested to promote the effective application of bone regeneration through the combination of in situ self-setting, plasticity, angiogenesis, and osteoconductivity. PMID:27524007

  4. Enhanced effect of β-tricalcium phosphate phase on neovascularization of porous calcium phosphate ceramics: in vitro and in vivo evidence.

    Science.gov (United States)

    Chen, Y; Wang, J; Zhu, X D; Tang, Z R; Yang, X; Tan, Y F; Fan, Y J; Zhang, X D

    2015-01-01

    Neovascularization plays a key role in bone repair and regeneration. In the present study, four types of porous calcium phosphate (CaP) ceramics, namely hydroxyapatite (HA), biphasic calcium phosphates (BCP-1 and BCP-2) and β-tricalcium phosphate (β-TCP), with HA to β-TCP ratios of 100/0, 70/30, 30/70 and 2/98, respectively, were investigated in terms of their angiogenic induction. The in vitro cell culture revealed that the ceramics could promote proliferation and angiogenesis of human umbilical vein endothelial cells (HUVECs). This result could be achieved by stimulating CCD-18Co human fibroblasts to secrete angiogenic factors (vascular endothelial growth factor, basic fibroblast growth factor and transforming growth factor-β) as a paracrine effect, as well as by up-regulating HUVECs to express these angiogenic factors and their receptors (KDR, FGFR1 and ACVRL1) and the downstream eNOS as an autocrine effect. These effects were more significant in β-TCP and BCP-2, which had a higher content of β-TCP phase. In the in vivo implantation into the thigh muscles of mice, the process of neovascularization of the ceramics was initiated at 2 weeks and the mature vascular networks were formed at 4 weeks as visualized by hematoxylin and eosin staining and scanning electron microscopy. Microvessel density count confirmed that β-TCP and BCP-2 induced more microvessels to form than HA or BCP-1. This phenomenon was further confirmed by the significantly up-regulated expressions of angiogenesis-related genes in the ingrowth of cells into the inner pores of the two ceramics. All the results confirmed the angiogenic induction of porous CaP ceramics, and a higher content of β-TCP phase had an enhanced effect on the neovascularization of the ceramics. PMID:25246313

  5. Biological and within-subject variability of calcium kinetics and biochemical markers of bone turnover

    Science.gov (United States)

    Bone loss is a critical issue during space flight. Evaluating changes in bone and calcium metabolism in astronauts often requires multiple preflight data collection points. Bone turnover and calcium kinetics were measured in 4 healthy subjects, and the day-to-day and between-subject variations were ...

  6. Effect of calcium phosphate crystals induced by uremic serum on calcification of human aortic smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    刘曜蓉

    2013-01-01

    Objective To investigate the impact of calcium phosphate crystals induced by uremic serum on calcification of human aortic smooth muscle cells (HASMCs) .Methods Uremic serum was incubated at 37℃for 3days.Calcium phosphate crystals and uremic supernatant were isolated from uremic serum by ultracentrifugation.

  7. Histologic Evaluation of Bone Healing Following Application of Anorganic Bovine Bone and β-tricalcium Phosphate in Rabbit Calvaria

    OpenAIRE

    AR. Rokn; Moslemi, N.; B. Eslami; H. Khandagh Abadi; M. Paknejad

    2012-01-01

    Objective: Both anorganic bovine bone (ABB) and β-tricalcium phosphate (β-TCP) are used in clinical practice as bone substitute materials, but there is limited data comparing these two materials in standardized defects. The aim of this study was to histologically evaluate the effectiveness of ABB and β-TCP in the healing of experimentally induced bone defects. Materials and Methods: Eighteen bone defects were created on the calvaria of six rabbits. In each animal, one defect was left untreate...

  8. A systematic review on the long-term success of calcium phosphate plasma-spray-coated dental implants.

    Science.gov (United States)

    van Oirschot, B A J A; Bronkhorst, E M; van den Beucken, J J J P; Meijer, G J; Jansen, J A; Junker, R

    2016-09-01

    The objectives of the current review were (1) to systematically appraise, and (2) to evaluate long-term success data of calcium phosphate (CaP) plasma-spray-coated dental implants in clinical trials with at least 5 years of follow-up. To describe the long-term efficacy of functional implants, the outcome variables were (a) percentage annual complication rate (ACR) and (b) cumulative success rate (CSR), as presented in the selected articles. The electronic search yielded 645 titles. On the basis of the inclusion criteria, 8 studies were finally included. The percentage of implants in function after the first year was estimated to be 98.4 % in the maxilla and 99.2 % in the mandible. The estimates of the weighted mean ACR-percentage increased over the years up to 2.6 (SE 0.7) during the fifth year of function for the maxilla and to 9.4 (SE 8.4) for the mandible in the tenth year of function. After 10 years, the mean percentage of successful implants was estimated to be 71.1 % in the maxilla and 72.2 % in the mandible. The estimates seem to confirm the proposed, long-term progressive bone loss pattern of CaP-ceramic-coated dental implants. Within the limits of this meta-analytic approach to the literature, we conclude that: (1) published long-term success data for calcium phosphate plasma-spray-coated dental implants are limited, (2) comparison of the data is difficult due to differences in success criteria among the studies, and (3) long-term CSRs demonstrate very weak evidence for progressive complications around calcium phosphate plasma-spray-coated dental implants.

  9. In vitro surface reaction layer formation and dissolution of calcium phosphate cement-bioactive glass composites

    Energy Technology Data Exchange (ETDEWEB)

    Liu Changsheng [Key Laboratory for Ultrafine Materials of Ministry of Education, and Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Chen, C.-W.; Ducheyne, Paul [Center for Bioactive Materials and Tissue Engineering, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104 (United States)], E-mail: liucs@ecust.edu.cn, E-mail: ducheyne@seas.upenn.edu

    2008-09-01

    Composites of hydrated calcium phosphate cement (CPC) and bioactive glass (BG) containing Si were immersed in vitro to study the effect of chemical composition on surface reaction layer formation and dissolution/precipitation behavior. The solutions used were 0.05 M tris hydroxymethyl aminomethane/HCl (tris buffer), tris buffer supplemented with plasma electrolyte (TE) with pH 7.4 at 37 deg. C, and this solution complemented with 10% newborn bovine serum (TES). The post-immersion solutions were analyzed for changes in Ca, PO{sub 4} and Si concentrations. The reacted surfaces were analyzed using Fourier transform infrared (FTIR), and scanning electron microscopy with energy dispersive x-ray analysis. The sample weight variations after immersion were also determined. The results showed that the composition of the bioactive composite CPCs greatly affected their behavior in solution and the formation of apatite bioactive surface reaction layers. After immersion in the TE solution, Ca ions were taken up by all samples during the entire immersion duration. Initially, the P ion concentration increased sharply, and then decreased. This reaction pattern reveals the formation of an amorphous calcium phosphate layer on the surface of these composite CPCs. FTIR revealed that the layer was, in fact, poorly crystallized Ca-deficient carbonate apatite. The thickness of the layer was 12-14 {mu}m and it was composed of rod-like apatite with directional arrangement. For immersion in the TES solution, the Ca and Si ion concentrations showed a similar behavior to that in TE, but the release rate of Si ions was higher. FTIR revealed that after TES immersion, not only did the typical, poorly crystallized, Ca-deficient carbonated apatite form, as it did in TE, but also the serum proteins co-adsorbed on the surface and thereby affected the surface reaction layer formation. A thinner apatite layer was formed and was composed of a micro-porous layer comprising rounded particles in a glue

  10. Building bones in babies: can and should we exceed the human milk-fed infant's rate of bone calcium accretion?

    Science.gov (United States)

    Increasing calcium absorption and bone calcium accretion to levels above those achieved by human milk-fed, full-term infants is possible with infant formulas. However, no data support such a goal or suggest that it is beneficial to short- or long-term bone health. Small differences in the bioavailab...

  11. Grafting cyclodextrins to calcium phosphate ceramics for biomedical applications

    DEFF Research Database (Denmark)

    Jacobsen, P.A.L.; Nielsen, J.L.; Juhl, M.V.;

    2012-01-01

    The grafting of hydroxyapatite/beta-tricalcium phosphate with β-cyclodextrin was achieved using a two step reaction with (3-glycidyloxypropyl)trimethoxysilane as a linker. Firstly, the silane group was brought to react with the hydroxyl groups at the surface of the hydroxyapatite/beta-tricalcium ...

  12. Effects of Silicate, Phosphate, and Calcium on the Stability of Aldopentoses

    Science.gov (United States)

    Nitta, Sakiko; Furukawa, Yoshihiro; Kakegawa, Takeshi

    2016-06-01

    Ribose is an important constituent of RNA: ribose connects RNA bases and forms a strand of sugar phosphates. Accumulation of ribose on prebiotic Earth was difficult because of its low stability. Improvement in the yield of ribose by the introduction of borate or silicate in a formose-like reaction has been proposed. The effects of borates have been further analyzed and confirmed in subsequent studies. Nonetheless, the effects of silicates and phosphates remain unclear. In the present study, we incubated aldopentoses in a highly alkaline aqueous solution at a moderate temperature to determine the effects of silicate or phosphate on the degradation rates of ribose and its isomeric aldopentoses. The formation of a complex of silicate (or phosphate) with ribose was also analyzed in experiments with 29Si and 31P nuclear magnetic resonance (NMR). We found that silicate or phosphate complexes of ribose were not detectable under our experimental conditions. The stability of ribose and lyxose improved after addition of 40-fold molar excess (relative to a pentose) of sodium silicate or sodium phosphate to the alkaline solution. The stability was not improved further when an 80-fold molar excess of sodium silicate or sodium phosphate was added. Calcium was removed from these solutions by precipitation of calcium salts. The drop in Ca2+ concentration might have improved the stability of ribose and lyxose, which are susceptible to aldol addition. The improvement of ribose stability by the removal of Ca2+ and by addition of silicate or phosphate was far smaller than the improvement by borate. Furthermore, all aldopentoses showed similar stability in silicate- and phosphate-containing solutions. These results clearly show that selective stabilization of ribose by borate cannot be replaced by the effects of silicate or phosphate; this finding points to the importance of borate in prebiotic RNA formation.

  13. 椎弓根螺钉系统加自固化磷酸钙人工骨灌注治疗胸腰椎骨折%Treatment of thoracolumbar vertebrae fractures with vertebral pedicle screw system and artificial bones filled with autosolidification calcium phosphate cement

    Institute of Scientific and Technical Information of China (English)

    曾忠友; 金才益; 陆金荣; 王斌; 徐阿炳

    2001-01-01

    目的探讨应用椎弓根螺钉系统及自固化磷酸钙人工骨(ACPC)灌注治疗胸腰椎骨折的效果。方法 1999年4月始,选择18例胸腰椎骨折患者,其中压缩型12例,爆裂型6例。伤后6 h~7 d行椎弓根螺钉系统固定、复位,同时加ACPC灌注伤椎。结果 18例患者除2例神经功能A级脊髓神经症状无改善外,其余均有Ⅰ~Ⅲ级的恢复,脊柱后凸角平均恢复21°,伤椎前缘高度平均恢复至98%,伤椎后缘侵入椎管骨块明显回纳。随访10~16个月,平均11.6个月。随访期间无内固定松动及断裂现象,无慢性腰背痛,伤椎高度及脊柱生理弧度无丢失。结论胸腰椎压缩型骨折是使用ACPC的最佳适应证。如术前影像检查明确有双侧椎弓根骨折,则为禁忌。只要手术适应证选择适当,术中操作仔细,椎弓根螺钉系统加ACPC灌注治疗胸腰椎骨折是一有效而又安全的方法,特别是后期伤椎高度和脊柱生理弧度得到很好的维持。%Objective To study the effect of vertebral pedicle screw system and artificial bones filled with autosolidification calcium phosphate cement(ACPC) on thoracolumbar vertebrae fractures.  Methods A total of 18 patients with thoracolumbar vertebrae fractures and with operative indications were treated with vertebral pedicle screw system and artificial bones filled with ACPC.  Results  Except 2 patients with the spinal cord function for Grade A, all the patients had the average improvement of Degree I to Degree Ⅲ on the aspect of spinal cord function. The kyphotic angle recovered averagely for 21°, the anterior height of the injured vertebral body was averagely restored to 98% of the normal, and the bone fragments that invaded into the spinal canal were obviously restored. During the following-up, loose or breakage of the internal fixation was not found, and there was no chronic lumbar back pain or loss of the normal spine curve and the

  14. Combination of simvastatin, calcium silicate/gypsum, and gelatin and bone regeneration in rabbit calvarial defects.

    Science.gov (United States)

    Zhang, Jing; Wang, Huiming; Shi, Jue; Wang, Ying; Lai, Kaichen; Yang, Xianyan; Chen, Xiaoyi; Yang, Guoli

    2016-01-01

    The present study was performed to determine whether simvastatin improves bone regeneration when combined with calcium silicate/gypsum and gelatin (CS-GEL). The surface morphology was determined using field-emission scanning electron microscopy (FSEM). Degradation in vitro was evaluated by monitoring the weight change of the composites soaked in phosphate buffered saline (PBS). Drug release was evaluated using high-performance liquid chromatography (HPLC). Cytotoxicity testing was performed to assess the biocompatibility of composites. Four 5 mm-diameter bone defects were created in rabbit calvaria. Three sites were filled with CS-GEL, 0.5 mg simvastatin-loaded CS-GEL (SIM-0.5) and 1.0 mg simvastatin-loaded CS-GEL (SIM-1.0), respectively, and the fourth was left empty as the control group. Micro-computed tomography (micro-CT) and histological analysis were carried out at 4 and 12 weeks postoperatively. The composites all exhibited three-dimensional structures and showed the residue with nearly 80% after 4 weeks of immersion. Drug release was explosive on the first day and then the release rate remained stable. The composites did not induce any cytotoxicity. The results in vivo demonstrated that the new bone formation and the expressions of BMP-2, OC and type I collagen were improved in the simvastatin-loaded CS-GEL group. It was concluded that the simvastatin-loaded CS-GEL may improve bone regeneration. PMID:26996657

  15. Combination of simvastatin, calcium silicate/gypsum, and gelatin and bone regeneration in rabbit calvarial defects

    Science.gov (United States)

    Zhang, Jing; Wang, Huiming; Shi, Jue; Wang, Ying; Lai, Kaichen; Yang, Xianyan; Chen, Xiaoyi; Yang, Guoli

    2016-03-01

    The present study was performed to determine whether simvastatin improves bone regeneration when combined with calcium silicate/gypsum and gelatin (CS-GEL). The surface morphology was determined using field-emission scanning electron microscopy (FSEM). Degradation in vitro was evaluated by monitoring the weight change of the composites soaked in phosphate buffered saline (PBS). Drug release was evaluated using high-performance liquid chromatography (HPLC). Cytotoxicity testing was performed to assess the biocompatibility of composites. Four 5 mm-diameter bone defects were created in rabbit calvaria. Three sites were filled with CS-GEL, 0.5 mg simvastatin-loaded CS-GEL (SIM-0.5) and 1.0 mg simvastatin-loaded CS-GEL (SIM-1.0), respectively, and the fourth was left empty as the control group. Micro-computed tomography (micro-CT) and histological analysis were carried out at 4 and 12 weeks postoperatively. The composites all exhibited three-dimensional structures and showed the residue with nearly 80% after 4 weeks of immersion. Drug release was explosive on the first day and then the release rate remained stable. The composites did not induce any cytotoxicity. The results in vivo demonstrated that the new bone formation and the expressions of BMP-2, OC and type I collagen were improved in the simvastatin-loaded CS-GEL group. It was concluded that the simvastatin-loaded CS-GEL may improve bone regeneration.

  16. The determination of calcium in phosphate, carbonate, and silicate rocks by flame photometer

    Science.gov (United States)

    Kramer, Henry

    1956-01-01

    A method has been developed for the determination of calcium in phosphate, carbonate, and silicate rocks using the Beckman flame photometer, with photomultiplier attachement. The sample is dissolved in hydrofluoric, nitric, and perchloric acids, the hydrofluoric and nitric acids are expelled, a radiation buffer consisting of aluminum, magnesium, iron, sodium, potassium, phosphoric acid, and nitric acid is added, and the solution is atomized in an oxy-hydrogen flame with an instrument setting of 554 mµ. Measurements are made by comparison against calcium standards, prepared in the same manner, in the 0 to 50 ppm range. The suppression of calcium emission by aluminum and phosphate was overcome by the addition of a large excess of magnesium. This addition almost completely restores the standard curve obtained from a solution of calcium nitrate. Interference was noted when the iron concentration in the aspirated solution (including the iron from the buffer) exceeded 100 ppm iron. Other common rock-forming elements did not interfere. The results obtained by this procedure are within ± 2 percent of the calcium oxide values obtained by other methods in the range 1 to 95 percent calcium oxide. In the 0 to 1 percent calcium oxide range the method compares favorably with standard methods.

  17. Combined Percutaneous Iliosacral Screw Fixation With Sacroplasty Using Resorbable Calcium Phosphate Cement for Osteoporotic Pelvic Fractures Requiring Surgery.

    Science.gov (United States)

    Collinge, Cory A; Crist, Brett D

    2016-06-01

    Osteoporotic sacral fractures, including acute and chronic insufficiency fractures, are increasing in frequency and present a number of management problem. Many of these patients are treated nonoperatively with relative immobility (eg, bedrest, wheelchair, or weight-bearing restrictions) and analgesics, which likely make the osteoporotic component worse. Surgery in this patient population may be desirable in some cases with the goals of improving mobility, relieving pain, and healing in an aligned position while minimizing deformity progression. However, internal fixation of the osteoporotic pelvis can be difficult. Large unicortical lag screws are the workhorse of posterior pelvic fixation, and yet fixation in cancellous bone corridors of an osteoporotic sacrum seems unlikely to achieve optimal fixation. As a result, the operative management and clinical results of these difficult injuries may not be uniformly successful. The authors present a technique for treating osteoporotic patients with a sacral fracture when operative treatment is indicated using percutaneous screw fixation combined with screw augmentation using a resorbable calcium phosphate bone substitute or "cement." The guide wire for a 7.3-mm or other large cannulated lag screw is fully inserted along the desired bony sacral corridor as is standard. The lag screw is then inserted over the wire to the depth where cement is desired. The guide wire is removed, and the aqueous calcium phosphate is injected through the screw's cannulation. For acute fractures, cement was applied to the areas distant to the fracture; whereas in insufficiency fractures, the cement was inserted along most of the screw path. The guide wire then can be reinserted and the lag screw fully inserted. The rationale for using these 2 modalities is their synergistic effect: the cannulated screw provides typical screw fixation and also a conduit for cement application. The cement augments the lag screw's purchase in osteoporotic bone

  18. Influence of surface microstructure and chemistry on osteoinduction and osteoclastogenesis by biphasic calcium phosphate discs.

    NARCIS (Netherlands)

    Davison, N.L.; Su, J.; Yuan, H.; Beucken, J.J.J.P van den; Bruijn, J.D. de; rrere-de Groot, F. Ba

    2015-01-01

    It has been reported that surface microstructural dimensions can influence the osteoinductivity of calcium phosphates (CaPs), and osteoclasts may play a role in this process. We hypothesised that surface structural dimensions of

  19. Lead Retention in a Calcareous Soil Influenced by Calcium and Phosphate Amendments

    Science.gov (United States)

    Phosphate amendments in calcareous lead (Pb)-contaminated soils to immobilize Pb may be hindered due to competition of Pb with calcium (Ca) that may inhibit the retention of Pb as a precipitation mechanism. This study explored the retention of Pb in a calcareous soil spiked and ...

  20. Dense and porous titanium substrates with a biomimetic calcium phosphate coating

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, A.A., E-mail: aantunesr@yahoo.com.br [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil); Balestra, R.M. [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil); Rocha, M.N. [Metallurgical and Materials Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68505, 21941-972 Rio de Janeiro, RJ (Brazil); Peripolli, S.B. [Materials Metrology Division, National Institute of Metrology, Normalization and Quality, No. 50 Nossa Senhora das Gracas Street, Building 3, 25250-020 Duque de Caxias, RJ (Brazil); Andrade, M.C. [Polytechnic Institute of Rio de Janeiro, Rio de Janeiro State University, s/n, Alberto Rangel Street, 28630-050 Nova Friburgo, RJ (Brazil); Pereira, L.C. [Metallurgical and Materials Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68505, 21941-972 Rio de Janeiro, RJ (Brazil); Oliveira, M.V. [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer A biomimetic coating method with simplified solution is proposed. Black-Right-Pointing-Pointer Titanium substrates are submitted to chemical and heat treatments. Black-Right-Pointing-Pointer Titanium substrates are coated with biocompatible calcium phosphate phases. Black-Right-Pointing-Pointer The simplified solution shows potential to be applied as a coating technique. - Abstract: The present work studied a biomimetic method using a simplified solution (SS) with calcium and phosphorus ions for coating titanium substrates, in order to improve their bioactivity. Commercially pure titanium dense sheet, microporous and macroporous titanium samples, both produced by powder metallurgy, were treated in NaOH solution followed by heat-treating and immersed in SS for 7, 14 or 21 days. The samples characterization was performed by quantitative metallographic analysis, confocal scanning optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and low angle X-ray diffraction. The results showed coatings with calcium phosphate precipitation in all samples, with globular or plate-like morphology, typical of hydroxyapatite and octacalcium phosphate, respectively, indicating that the solution (SS) has potential for coating titanium substrates. In addition, the different surfaces of substrates had an effect on the formed calcium phosphate phase and thickness of coatings, depending on the substrate type and imersion time in the simplified solution.

  1. Novel tea polyphenol-modified calcium phosphate nanoparticle and its remineralization potential

    NARCIS (Netherlands)

    L. He; D. Deng; X. Zhou; L. Cheng; J.M. ten Cate; J. Li; X. Li; W. Crielaard

    2015-01-01

    Tea polyphenols (TP) are not only potent antimicrobial and antioxidant agents but also effective modifiers in the formation of nanosized crystals. Since nano-hydroxyapatite (n-HA) is known to enhance remineralization of dental hard tissue, our aims were to synthesize nanosized calcium phosphate part

  2. Mechanical evaluation of implanted calcium phosphate cement incorporated with PLGA microparticles.

    NARCIS (Netherlands)

    Link, D.P.; Dolder, J. van den; Jurgens, W.J.; Wolke, J.G.C.; Jansen, J.A.

    2006-01-01

    In this study, the mechanical properties of an implanted calcium phosphate (CaP) cement incorporated with 20wt% poly (dl-lactic-co-glycolic acid) (PLGA) microparticles were investigated in a rat cranial defect. After 2, 4 and 8 weeks of implantation, implants were evaluated mechanically (push-out te

  3. Theoretical and experimental approach to test the cohesion of calcium phosphate pastes

    Directory of Open Access Journals (Sweden)

    M Bohner

    2006-08-01

    Full Text Available Recent studies have revealed that the ability of a calcium phosphate cement paste to harden in a physiological environment without desintegrating into small particles might be a key property to ensure a safe and reliable clinical use of calcium phosphate cements. However, this property called cohesion is not well understood and has not been studied extensively. The goal of the present study was to better understand which factors affect the cohesion of a calcium phosphate paste using the combination of a theoretical and experimental approach. In the theoretical approach, factors expected to influence the paste cohesion such as Van der Waals forces, electrostatic and steric interactions, as well as osmotic effects were listed and discussed. In the experimental approach, a new method to measure the cohesion of a non-setting calcium phosphate paste was presented and used to assess the effects of various factors on this property. The new method allowed a continuous measurement of cohesion and gave reproducible results. The experimental results confirmed the theoretical predictions: an increase of the liquid-to-powder ratio of the paste and of the powder particle size, as well as the addition of citrate ions and in limited cases dissolved xanthan polymer chains reduced the paste cohesion.

  4. The effects of inorganic additives to calcium phosphate on in vitro behavior of osteoblasts and osteoclasts

    NARCIS (Netherlands)

    Yang, Liang; Perez-Amodio, Soledad; Barrere-de Groot, Florence Y.F.; Everts, Vincent; Blitterswijk, van Clemens A.; Habibovic, Pamela

    2010-01-01

    This study describes a medium-throughput system based on deposition of calcium phosphate films in multi-well tissue culture plates that can be used to study the effect of inorganic additives on the behavior of osteoblasts and osteoclasts in a standardized manner. All tested elements, copper, zinc, s

  5. Preliminary research on a novel bioactive silicon doped calcium phosphate coating on AZ31 magnesium alloy via electrodeposition.

    Science.gov (United States)

    Qiu, Xun; Wan, Peng; Tan, Lili; Fan, Xinmin; Yang, Ke

    2014-03-01

    A silicon doped calcium phosphate coating was obtained successfully on AZ31 alloy substrate via pulse electrodeposition. A novel dual-layer structure was observed with a porous lamellar-like and outer block-like apatite layer. In vitro immersion tests were adopted in simulated body fluid within 28 days of immersion. Slow degradation rate obtained from weight loss was observed for the Si-doped Ca-P coating, which was also consistent with the results of electrochemical experiments showing an enhanced corrosion resistance for the coating. Further formation of an apatite-like layer on the surface after immersion proved better integrity and biomineralization performance of the coating. Biological characterization was carried out for viability, proliferation and differentiation of MG63 osteoblast-like cells. The coating showed a good cell growth and an enhanced cell proliferation. Moreover, an increased activity of osteogenic marker ALP was found. All the results demonstrated that the Si-doped calcium phosphate was perspective to be used as a coating for magnesium alloy implants to control the degradation rate and enhance the bioactivity, which would facilitate the rapidity of bone tissue repair. PMID:24433888

  6. An efficient calcium phosphate nanoparticle-based nonviral vector for gene delivery

    Directory of Open Access Journals (Sweden)

    Liu YC

    2011-04-01

    Full Text Available Yachun Liu1,2,*, Tao Wang1,*, Fangli He1,*, Qian Liu1,*, Dexi Zhang2, Shuanglin Xiang1, Shengpei Su2, Jian Zhang11Key Laboratory of Protein Chemistry and Developmental Biology, Ministry of Education of China, College of Life Sciences; 2Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Sustainable Resources Processing and Advanced Materials of Hunan Province, Ministry of Education of China, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, China*These authors contributed equally to this workBackground: Smaller nanoparticles facilitate the delivery of DNA into cells through endocytosis and improve transfection efficiency. The aim of this study was to determine whether protamine sulfate-coated calcium phosphate (PS-CaP could stabilize particle size and enhance transfection efficiency.Methods: pEGFP-C1 green fluorescence protein was employed as an indicator of transfection efficiency. Atomic force microscopy was used to evaluate the morphology and the size of the particles, and an MTT assay was introduced to detect cell viability and inhibition. The classical calcium phosphate method was used as the control.Results: Atomic force microscopy images showed that the PS-CaP were much smaller than classical calcium phosphate particles. In 293 FT, HEK 293, and NIH 3T3 cells, the transfection efficiency of PS-CaP was higher than for the classical calcium phosphate particles. The difference in efficiencies implies that the smaller nanoparticles may promote the delivery of DNA into cells through endocytosis and could improve transfection efficiency. In addition, PS-CaP could be used to transfect HEK 293 cells after one week of storage at 4°C with a lesser extent of efficiency loss compared with classical calcium phosphate, indicating that protamine sulfate may increase the stability of calcium phosphate nanoparticles. The cell viability inhibition assay indicated that

  7. In-situ observation on the transformation of calcium phosphate cement into hydroxyapatite

    International Nuclear Information System (INIS)

    In the present study, the in-situ transformation of calcium phosphate cement into hydroxyapatite (HAp) within the first hour is monitored with a synchrotron X-ray beam. A disodium hydrogen phosphate solution is used as cement liquid to activate the reaction between dicalcium phosphate anhydrous (DCPA) and calcium hydroxide (Ca(OH)2). The XRD analysis indicates that the amounts of DCPA and Ca(OH)2 first decrease within the first min of the reaction. Then, the intensity of DCPA's XRD peaks starts to increase instead in the period of 5 to 20 min. After 20 min, the DCPA particles are consumed slowly to form fine HAp particles. Large pores are evident upon the completion of reaction.

  8. Synthesis and characterization of nanocomposite powders of calcium phosphate/silica-gel; Sintese e caracterizacao de pos nanoestruturados de fosfato de calcio/silica-gel

    Energy Technology Data Exchange (ETDEWEB)

    Muller, D.T.; Delima, S.A. [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Dept. de Engenharia Mecanica; Santos, R.B.M.; Camargo, N.H.A., E-mail: dem2nhac@joinville.udesc.b [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Programa de Pos Graduacao em Ciencia e Engenharia de Materiais

    2009-07-01

    In the recent years ceramics of calcium phosphate are pointed out as an outstanding material in substitution and regeneration in defects from osseous tissue, in reason of their similar mineralogical characteristics of apatite of bone structure. However, the challenge with phosphate calcium ceramics find out about the mechanical properties and the development of biomaterials similar of the bone structure, what sometimes is not so easy, about fragile materials. The aim of this work focused in synthesis and characterization nanocomposites powders of calcium phosphate/silica-gel with percentages 1, 2, 3 e 5% of nanometric silica. The method synthesis used for the compositions elaboration was dissolution-precipitation. The presented results are related with the optimization to method elaboration of nanostructured powders, the mineralogical characterization with X-ray diffraction, thermal behavior with thermal differential analysis, differential scanning calorimetry here is ADT and dilatometer. The scanning electronic microscopy was used to help of morphological characterization the nanostructured powders and the surfaces from body test recovered from the mechanical test. (author)

  9. Phase stability of silver particles embedded calcium phosphate bioceramics

    Indian Academy of Sciences (India)

    Brajendra Singh; Samayendra Kumar; Naresh Saha; Bikramjit Basu; Rajeev Gupta

    2015-04-01

    In this paper, we report the compositional variation-dependent phase stability of hydroxyapatite (Ca10(PO4)6(OH)2) on doping with silver. The transformation of hydroxyapatite to (/) tricalcium phosphate phases during sintering has been explored using Raman spectroscopy and X-ray diffraction techniques. The optical absorption spectroscopy analysis reveals the presence of Ag+ ions at low doping levels. As the doping increases, abundance of Ag particles is enhanced.

  10. Kinetics and Mechanism of Adsorption of Phosphate on Fluorine-containing Calcium Silicate

    Institute of Scientific and Technical Information of China (English)

    ZHU Xinhua; ZHANG Zhao; SHEN Jun

    2016-01-01

    The nanowires-reticulated calcium silicate with a speciifc surface area more than 100 m2/g was prepared by a hydrothermal process using hydrated lime (Ca(OH)2, HL) and silica containing soluble lfuoride, which was a by-product of lfuorine industry, and the soluble lfuoride in raw silica was ifxed as CaSiF6 at the same time. The kinetic characteristics and mechanism of adsorbing phosphate by lfuorine-containing calcium silicate were investigated in the experiments of phosphorus (P) removal from aqueous solution. The results show that the prepared lfuorine-containing calcium silicate has excellent performance for adsorbing phosphate, the adsorption process appears to follow pseudo-second-order reaction kinetics and the process is mainly controlled by chemisorption. The product resulted from P adsorption is mainly composed of hydroxyapatite (HAP) and lfuorapatite (FAP), which are further used as adsorbents of heavy metal ion Cd2+ in aqueous solution and display excellent performance.

  11. Plum and soy aglycon extracts superior at increasing bone calcium retention in ovariectomized Sprague Dawley rats.

    Science.gov (United States)

    Pawlowski, Jessica W; Martin, Berdine R; McCabe, George P; Ferruzzi, Mario G; Weaver, Connie M

    2014-07-01

    Plant-derived polyphenols have been shown to influence bone turnover and bone properties in the estrogen-depleted state. We used a crossover design in ovariectomized rats (n = 16 rats for each diet) to investigate the effect of supplementation of two doses each of blueberry, plum, grape, grape seed extract, and resveratrol on bone. We tested the aglycon and glucoside forms of genistein to quantify differences in efficacy on bone calcium retention. Rats were given an intravenous dose of ⁴⁵Ca to prelabel bone, and bone calcium retention was assessed by urinary excretion of ⁴⁵Ca:Ca ratio during an intervention period compared with nonintervention. Genistein aglycon increased bone calcium retention significantly (pcalcium retention by 20% (p=0.0153) and 14% (p=0.0012), respectively. Several polyphenolic-rich diets improved bone calcium retention.

  12. Effects of dietary phosphate on adynamic bone disease in rats with chronic kidney disease--role of sclerostin?

    Science.gov (United States)

    Ferreira, Juliana C; Ferrari, Guaraciaba O; Neves, Katia R; Cavallari, Raquel T; Dominguez, Wagner V; Dos Reis, Luciene M; Graciolli, Fabiana G; Oliveira, Elizabeth C; Liu, Shiguang; Sabbagh, Yves; Jorgetti, Vanda; Schiavi, Susan; Moysés, Rosa M A

    2013-01-01

    High phosphate intake is known to aggravate renal osteodystrophy along various pathogenetic pathways. Recent studies have raised the possibility that dysregulation of the osteocyte Wnt/β-catenin signaling pathway is also involved in chronic kidney disease (CKD)-related bone disease. We investigated the role of dietary phosphate and its possible interaction with this pathway in an experimental model of adynamic bone disease (ABD) in association with CKD and hypoparathyroidism. Partial nephrectomy (Nx) and total parathyroidectomy (PTx) were performed in male Wistar rats. Control rats with normal kidney and parathyroid function underwent sham operations. Rats were divided into three groups and underwent pair-feeding for 8 weeks with diets containing either 0.6% or 1.2% phosphate: sham 0.6%, Nx+PTx 0.6%, and Nx+PTx 1.2%. In the two Nx+PTx groups, serum creatinine increased and blood ionized calcium decreased compared with sham control group. They also presented hyperphosphatemia and reduced serum parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) levels. Fractional urinary excretion of phosphate increased in Nx+PTx 1.2% rats despite lower PTH and FGF23 levels than in sham group. These biochemical changes were accompanied by a decrease in bone formation rates. The Nx+PTx 1.2% group had lower bone volume (BV/TV), higher osteoblast and osteocyte apoptosis, and higher SOST and Dickkopf-1 gene expression than the Nx+PTx 0.6% group. Nx+PTx 0.6% rat had very low serum sclerostin levels, and Nx+PTx 1.2% had intermediate sclerostin levels compared with sham group. Finally, there was a negative correlation between BV/TV and serum sclerostin. These results suggest that high dietary phosphate intake decreases bone volume in an experimental model of CKD-ABD, possibly via changes in SOST expression through a PTH-independent mechanism. These findings could have relevance for the clinical setting of CKD-ABD in patients who low turnover bone disease might be attenuated

  13. Effects of dietary phosphate on adynamic bone disease in rats with chronic kidney disease--role of sclerostin?

    Directory of Open Access Journals (Sweden)

    Juliana C Ferreira

    Full Text Available High phosphate intake is known to aggravate renal osteodystrophy along various pathogenetic pathways. Recent studies have raised the possibility that dysregulation of the osteocyte Wnt/β-catenin signaling pathway is also involved in chronic kidney disease (CKD-related bone disease. We investigated the role of dietary phosphate and its possible interaction with this pathway in an experimental model of adynamic bone disease (ABD in association with CKD and hypoparathyroidism. Partial nephrectomy (Nx and total parathyroidectomy (PTx were performed in male Wistar rats. Control rats with normal kidney and parathyroid function underwent sham operations. Rats were divided into three groups and underwent pair-feeding for 8 weeks with diets containing either 0.6% or 1.2% phosphate: sham 0.6%, Nx+PTx 0.6%, and Nx+PTx 1.2%. In the two Nx+PTx groups, serum creatinine increased and blood ionized calcium decreased compared with sham control group. They also presented hyperphosphatemia and reduced serum parathyroid hormone (PTH and fibroblast growth factor 23 (FGF23 levels. Fractional urinary excretion of phosphate increased in Nx+PTx 1.2% rats despite lower PTH and FGF23 levels than in sham group. These biochemical changes were accompanied by a decrease in bone formation rates. The Nx+PTx 1.2% group had lower bone volume (BV/TV, higher osteoblast and osteocyte apoptosis, and higher SOST and Dickkopf-1 gene expression than the Nx+PTx 0.6% group. Nx+PTx 0.6% rat had very low serum sclerostin levels, and Nx+PTx 1.2% had intermediate sclerostin levels compared with sham group. Finally, there was a negative correlation between BV/TV and serum sclerostin. These results suggest that high dietary phosphate intake decreases bone volume in an experimental model of CKD-ABD, possibly via changes in SOST expression through a PTH-independent mechanism. These findings could have relevance for the clinical setting of CKD-ABD in patients who low turnover bone disease might

  14. Pulsed electrodeposition for the synthesis of strontium-substituted calcium phosphate coatings with improved dissolution properties

    Energy Technology Data Exchange (ETDEWEB)

    Drevet, Richard, E-mail: richard.drevet@univ-reims.fr; Benhayoune, Hicham

    2013-10-15

    Strontium-substituted calcium phosphate coatings are synthesized by pulsed electrodeposition on titanium alloy (Ti6Al4V) substrates. Experimental conditions of the process are optimized in order to obtain a coating with a 5% atomic substitution of calcium by strontium which corresponds to the best observations on the osteoblast cells activity and on the osteoclast cells proliferation. The physical and chemical characterizations of the obtained coating are carried out by scanning electron microscopy associated to energy dispersive X-ray spectroscopy (EDXS) for X-ray microanalysis and the structural characterization of the coating is carried out by X-ray diffraction. The in vitro dissolution/precipitation properties of the coated substrates are investigated by immersion into Dulbecco's Modified Eagle Medium (DMEM) from 1 h to 14 days. The calcium, phosphorus and strontium concentrations variations in the biological liquid are assessed by Induced Coupled Plasma - Atomic Emission Spectroscopy for each immersion time. The results show that under specific experimental conditions, the electrodeposition process is suitable to synthesize strontium-substituted calcium phosphate coatings. Moreover, the addition of hydrogen peroxide (H{sub 2}O{sub 2}) into the electrolytic solution used in the process allows us to observe a control of the strontium release during the immersion of the prosthetic materials into DMEM. - Highlights: • Strontium-substituted calcium phosphate coatings are successfully electrodeposited. • The strontium is homogeneously distributed in the synthesized prosthetic coating. • This divalent cation modifies the calcium phosphate structure. • H{sub 2}O{sub 2} addition in the electrolyte allows to control the coating's stoichiometry. • This implies a control of the strontium release in the physiological environment.

  15. Local treatment of osteoporosis with alendronate-loaded calcium phosphate cement

    Institute of Scientific and Technical Information of China (English)

    Zhao Jindong; Tang Hai; Wang Jiayang; Li Gang

    2014-01-01

    Background A new treatment strategy is to target specific areas of the skeletal system that are prone to clinically significant osteoporotic fractures.We term this strategy as the "local treatment of osteoporosis".The study was performed to investigate the effect of alendronate-loaded calcium phosphate cement (CPC) as a novel drug delivery system for local treatment of osteoorosis.Methods An in vitro study was performed using CPC fabricated with different concentrations of alendronate (ALE,0,2,5,10 weight percent (wt%)).The microstructure,setting time,infrared spectrum,biomechanics,drug release,and biocompatibility of the composite were measured in order to detect changes when mixing CPC with ALE.An in vivo study was also performed using 30 Sprague-Dawley rats randomly divided into six groups:normal,Sham (ovariectomized (OVX) + Sham),CPC with 2% ALE,5%ALE,and 10% ALE groups.At 4 months after the implantation of the composite,animals were sacrificed and the caudal vertebrae (levels 4-7) were harvested for micro-CT examination and biomechanical testing.Results The setting time and strength of CPC was significantly faster and greater than the other groups.The ALE release was sustained over 21 days,and the composite showed good biocompatibility.In micro-CT analysis,compared with the Sham group,there was a significant increase with regard to volumetric bone mineral density (BMD) and trabecular number (Tb.N) in the treated groups (P <0.05).Trabecular spacing (Tb.Sp) showed a significant increase in the Sham group compared to other groups (P <0.01).However,trabecular thickness (Tb.Th) showed no significant difference among the groups.In biomechanical testing,the maximum compression strength and stiffness of trabecular bone in the Sham group were lower than those in the experimental groups.Conclusions The ALE-loaded CPC displayed satisfactory properties in vitro,which can reverse the OVX rat vertebral trabecular bone microarchitecture and biomechanical

  16. A comparative study of calcium sulfate artificial bone graft versus allograft in the reconstruction of bone defect after tumor curettage

    Institute of Scientific and Technical Information of China (English)

    Yang Yongkun; Niu Xiaohui; Zhang Qing; Hao Lin; Ding Yi; Xu Hairong

    2014-01-01

    Background Cavity reconstruction after benign bone tumor removal is varied and controversial.AIIograft is widely used but is associated with complications.New bone substitutes,such as calcium sulfate artificial bone,have been introduced for bone tumor operation.However,the bone healing response of artificial bone has not been compared with allograft bone.We therefore compared calcium sulfate grafts (study group) with bone allografts (control group) for the treatment of benign bone tumors.Methods We retrospectively reviewed 50 patients who underwent calcium sulfate reconstruction and 50 patients who underwent allograft cancellous bone reconstruction.The two groups were well matched.The mean follow-up time of the study group was 19.9 (12-55) months.We investigated bone healing response,complications,and factors affecting bone healing.Results At the last follow-up,84% (42/50) of cases in the study group and 62% (31/50) of cases in the control group had achieved clinical healing (P=0.013).The initial healing rate showed no significant difference between the two groups (100% vs.96%,P=0.153).The mean healing times for calcium sulfate and allograft bone were 9.6 (3-42) months and 13.8 (3-36) months,respectively (P <0.01).Complications in the study group were minor and resolved.Implant volume was a significant factor affecting bone healing.Conclusion The calcium sulfate bone substitute showed a satisfactory healing outcome and safety profile in reconstruction of bone defects after benign bone tumor curettage,especially in smaller cavities.

  17. Bio-hybrid silk fibroin/calcium phosphate/PLGA nanocomposite scaffold to control the delivery of vascular endothelial growth factor

    Energy Technology Data Exchange (ETDEWEB)

    Farokhi, Mehdi, E-mail: mehdi13294@yahoo.com [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mottaghitalab, Fatemeh, E-mail: fatemeh.motaghi@gmail.com [Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University (TMU), Tehran (Iran, Islamic Republic of); Shokrgozar, Mohammad Ali, E-mail: mashokrgozar@pasteur.ac.ir [National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Ai, Jafar, E-mail: jafar_ai@tums.ac.ir [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Hadjati, Jamshid; Azami, Mahmoud [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-02-01

    This study investigated the efficacy of bio-hybrid silk fibroin/Calcium phosphate/PLGA nanocomposite scaffold as vascular endothelial growth factor (VEGF) delivery system. The scaffold was fabricated using freeze-drying and electrospinning. Here, we highlight the structural changes of the scaffold using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and differential scanning calorimetry (DSC). The uniform dispersion of calcium phosohate (CaP) powder within silk fibroin (SF) solution was also confirmed using Zeta potential analysis. Moreover, good biocompatibility of osteoblast cells next to the scaffold was approved by cell adhesion, proliferation and alkaline phosphatase production. The release profile of VEGF during 28 days has established the efficacy of the scaffold as a sustained delivery system. The bioactivity of the released VEGF was maintained about 83%. The histology analysis has shown that the new bone tissue formation happened in the defected site after 10 weeks of implantation. Generally, our data showed that the fabricated scaffold could be considered as an effective scaffold for bone tissue engineering applications. - Highlights: • Silk fibroin/calcium phosphate/PLGA scaffold was successfully fabricated using freeze-drying and electrospinning. • The scaffold could control the release of VEGF during 28 days. • The bioactivity of electrospun VEGF was above 80%. • VEGF loaded scaffold could induce bone regeneration after 10 weeks in rabbit.

  18. Thermally induced crystallization and phase evolution in powders derived from amorphous calcium phosphate precipitates with a Ca/P ratio of 1:1

    Science.gov (United States)

    Zyman, Zoltan; Epple, Matthias; Goncharenko, Anton; Rokhmistrov, Dmytro; Prymak, Oleg; Loza, Kateryna

    2016-09-01

    Calcium phosphate powders of calcium pyrophosphate α1-CPP (the metastable phase of the high-temperature polymorph α-CPP) and the polymorph β-CPP (stable in this range), of α1-CPP, β-CPP, α1-TCP (metastable polymorph of the high-temperature phase α-tricalcium phosphate) and β-tricalcium phosphate β-TCP were prepared by heating amorphous calcium phosphate (ACP) precipitates with the nominal Ca/P ratio of 1:1 by nitrate synthesis. α1-CPP/β-CPP resulted from a crystallization at 530-640 °C and subsequent heating to 980 °C of unwashed and lyophilized ACP. α1-CPP/β-CPP/α1-TCP/β-TCP was formed by crystallization at 620-720 °C, followed by heating of six-time washed and lyophilized ACP precipitates from an ultra-short synthesis. The activation energy for the crystallization of ACP to α1-CPP was determined with 165 kJ mol-1. The reason for the occurrence of the TCP phases (Ca/P ratio=1.5) from ACP (Ca/P ratio=1) is discussed. The powders are prospective biomaterials for bone substitution because they combine effective bioactive phases with the metastable polymorphs α1-CPP and α1-TCP.

  19. Multifunctional nanocrystalline calcium phosphates loaded with Tetracycline antibiotic combined with human adipose derived mesenchymal stromal stem cells (hASCs).

    Science.gov (United States)

    Marycz, K; Pazik, R; Zawisza, K; Wiglusz, K; Maredziak, M; Sobierajska, P; Wiglusz, R J

    2016-12-01

    Osteoconductive drug delivery system composed of nanocrystalline calcium phosphates (Ca10(PO4)6(OH)2/β-Ca3(PO4)2) co-doped with Yb(3+)/Er(3+) ions loaded with Tetracycline antibiotic (TC) was developed. Their effect on human adipose derived mesenchymal stromal stem cells (hASCs) as a potential reconstructive biomaterial for bone tissue regeneration was studied. The XRD and TEM measurements were used in order to determine the crystal structure and morphology of the final products. The characteristics of nanocomposites with the TC and hASCs as potential regenerative materials as well as the antimicrobial activity of the nanoparticles against: Staphylococcus aureus ATCC 25923 as a model of the Gram-positive bacteria, Escherichia coli ATCC 8739 of the Gram-negative bacteria, were shown. These combinations can be a promising material for theranostic due to its regenerative, antimicrobial and fluorescent properties. PMID:27612684

  20. A novel squid pen chitosan/hydroxyapatite/β-tricalcium phosphate composite for bone tissue engineering

    International Nuclear Information System (INIS)

    Squid pen chitosan was used in the fabrication of biocomposite scaffolds for bone tissue engineering. Hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) obtained from waste mussel shells were used as the calcium phosphate source. The composite was prepared using 2.5% tripolyphosphate (TPP) and 1% glycerol as a cross-linker and plasticizer, respectively. The weight percent (wt.%) ratios of the ceramic components in the composite were 20/10/70, 30/20/50 and 40/30/30 (HA/β-TCP/Chi). The biodegradation rate and structural properties of the scaffolds were investigated. Scanning electron microscopy (SEM) and microCT(μCT) results indicated that the composites have a well defined lamellar structure with an average pore size of 200 μm. The porosity of the composites decreased from 88 to 56% by increasing the ratio of HA/β-TCP from 30 to 70%. After 28 days of incubation in a physiological solution, the scaffolds were degraded by approximately 30%. In vitro investigations showed that the composites were cytocompatible and supported the growth of L929 and Saos-2 cells. The obtained data suggests that the squid pen chitosan composites are potential candidates for bone regeneration. - Highlights: • Biocomposite scaffolds were made from mussel shells HA and β-TCP, and squid pin chitosan. • The porosity of the composites decreased with an increase in HA/β-TCP ratio. • Composites were cytocompatible and supported the growth of L929 and Saos-2 cells. • Composite containing 50% HA and β-TCP had the best mechanical properties

  1. A novel squid pen chitosan/hydroxyapatite/β-tricalcium phosphate composite for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shavandi, Amin, E-mail: amin.shavandi@postgrad.otago.ac.nz [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Department of Applied Sciences, University of Otago, Dunedin (New Zealand); Bekhit, Alaa El-Din A. [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Sun, Zhifa; Ali, Azam [Department of Physics, University of Otago, Dunedin (New Zealand); Gould, Maree [Department of Anatomy, University of Otago, Dunedin (New Zealand)

    2015-10-01

    Squid pen chitosan was used in the fabrication of biocomposite scaffolds for bone tissue engineering. Hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) obtained from waste mussel shells were used as the calcium phosphate source. The composite was prepared using 2.5% tripolyphosphate (TPP) and 1% glycerol as a cross-linker and plasticizer, respectively. The weight percent (wt.%) ratios of the ceramic components in the composite were 20/10/70, 30/20/50 and 40/30/30 (HA/β-TCP/Chi). The biodegradation rate and structural properties of the scaffolds were investigated. Scanning electron microscopy (SEM) and microCT(μCT) results indicated that the composites have a well defined lamellar structure with an average pore size of 200 μm. The porosity of the composites decreased from 88 to 56% by increasing the ratio of HA/β-TCP from 30 to 70%. After 28 days of incubation in a physiological solution, the scaffolds were degraded by approximately 30%. In vitro investigations showed that the composites were cytocompatible and supported the growth of L929 and Saos-2 cells. The obtained data suggests that the squid pen chitosan composites are potential candidates for bone regeneration. - Highlights: • Biocomposite scaffolds were made from mussel shells HA and β-TCP, and squid pin chitosan. • The porosity of the composites decreased with an increase in HA/β-TCP ratio. • Composites were cytocompatible and supported the growth of L929 and Saos-2 cells. • Composite containing 50% HA and β-TCP had the best mechanical properties.

  2. Effect of Fluoride, Casein Phosphopeptide–Amorphous Calcium Phosphate and Casein Phosphopeptide–Amorphous Calcium Phosphate Fluoride on Enamel Surface Microhardness After Microabrasion: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Ghazaleh Ahmadi Zenouz

    2016-03-01

    Full Text Available Objectives: This study aimed to assess the effect of applying casein phosphopeptide–amorphous calcium phosphate (CPP-ACP paste, casein phosphopeptide–amorphous calcium phosphate fluoride (CPP-ACPF paste and sodium fluoride gel on surface microhardness of enamel after microabrasion.Materials and Methods: Thirty freshly extracted human premolars were selected. All samples were subjected to hardness indentations made with the Vickers hardness machine and the average value was recorded as the initial surface microhardness. The specimens were then randomly divided into three groups (n=10 of CPP-ACPF, fluoride and CPP-ACP. The teeth were micro-abraded with Opalustre. Microhardness test was performed to assess the post-abrasion hardness. Three remineralization modalities were performed on samples of each group. The enamel surface microhardness measurements were performed. To compare the difference between groups, the rehardening and softening values were defined. One-way ANOVA and Tukey’s post hoc test at a significance level of 5% were used for statistical analysis.Results: The mean microhardness value (MMV had a significant decrease after microabrasion from baseline. The MMV had a significant increase after remineralization in all groups. The MMV of CPP-ACPF group was significantly more than that of fluoride group (P=0.027. The rehardening value of fluoride group was significantly more than that of other groups (P<0.001.Conclusion: All the remineralizing agents were effective for rehardening the enamel after microabrasion. The CPP-ACP and CPP-ACPF pastes are effective, but to a lesser extent than neutral sodium fluoride gel in remineralizing enamel surface. Incorporation of fluoride to CPP-ACP formulation does not provide any additional remineralizing potential.Keywords: Casein phosphopeptide-amorphous calcium phosphate nanocomplex; Enamel Microabrasion; Hardness; Sodium Fluoride

  3. In vitro aging of a calcium phosphate cement.

    Science.gov (United States)

    Bohner, M; Merkle, H P; Lemaître, J

    2000-03-01

    Cement samples made of beta-tricalcium phoshate (beta-TCP), phosphoric acid (PA) and water mixtures were incubated in several aqueous solutions to determine their stability over time. The effects of the cement composition and the incubating temperature were investigated in more detail. The cement samples contained mostly dicalcium phosphate dihydrate (DCPD) and remnants of beta-TCP crystals. Depending on the initial cement composition, a certain amount of dicalcium phosphate (DCP) crystals were formed. The larger the initial PA concentration, the larger the DCP amount. After setting, the cement composition was stable for at least 16 days up to 60 degrees C. Above that temperature, the DCPD crystals decomposed into DCP crystals. The latter reaction provoked a decrease of the pH of the incubation solution, phenomenon expected for a cement sample containing an excess of PA. As the cement samples contained an excess of beta-TCP, it was postulated that beta-TCP crystals became so covered by DCP or DCPD crystals during setting that the setting reaction was stopped prematurely. The latter phenomenon gave a good explanation for the low pH values measured in the incubation solutions.

  4. Calcium Carbonate versus Sevelamer Hydrochloride as Phosphate Binders after Long-Term Disease Progression in 5/6 Nephrectomized Rats

    Directory of Open Access Journals (Sweden)

    Suvi Törmänen

    2014-01-01

    Full Text Available Our aim was to compare the effects of calcium carbonate and sevelamer-HCl treatments on calcium-phosphate metabolism and renal function in 5/6 nephrectomized (NX rats so that long-term disease progression preceded the treatment. After 15-week progression, calcium carbonate (3.0%, sevelamer-HCl (3.0%, or control diets (0.3% calcium were given for 9 weeks. Subtotal nephrectomy reduced creatinine clearance (−40%, plasma calcidiol (−25%, and calcitriol (−70% and increased phosphate (+37%, parathyroid hormone (PTH (11-fold, and fibroblast growth factor-23 (FGF-23 (4-fold. In NX rats, calcium carbonate diet increased plasma (+20% and urinary calcium (6-fold, reduced plasma phosphate (−50% and calcidiol (−30%, decreased creatinine clearance (−35% and FGF 23 (−85%, and suppressed PTH without influencing blood pH. In NX rats, sevelamer-HCl increased urinary calcium (4-fold and decreased creatinine clearance (−45%, PTH (−75%, blood pH (by 0.20 units, plasma calcidiol (−40%, and calcitriol (−65%. Plasma phosphate and FGF-23 were unchanged. In conclusion, when initiated after long-term progression of experimental renal insufficiency, calcium carbonate diet reduced plasma phosphate and FGF-23 while sevelamer-HCl did not. The former induced hypercalcemia, the latter induced acidosis, while both treatments reduced vitamin D metabolites and deteriorated renal function. Thus, delayed initiation influences the effects of these phosphate binders in remnant kidney rats.

  5. Ectopic bone formation cannot occur by hydroxyapatite/β-tricalcium phosphate bioceramics in green fluorescent protein chimeric mice

    Science.gov (United States)

    Cheng, Lijia; Duan, Xin; Xiang, Zhou; Shi, Yujun; Lu, Xiaofeng; Ye, Feng; Bu, Hong

    2012-12-01

    Many studies have shown that calcium phosphate ceramics (CP) have osteoconductive and osteoinductive properties; however, the exact mechanism of bone induction has not yet been reported. This study was performed to investigate if destroying immunological function will influence osteogenesis, to explain the mechanism which is unclear. In this study, twenty C57BL/6 mice were divided into two groups (n = 10), in group 1, a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ceramic was implanted into both the left and right leg muscles of each mouse; in group 2, ten mice experienced lethal irradiation, then were injected bone marrow (BM) cells from green fluorescent protein (GFP) transgenic mice by tail veil, after bone marrow transplantation (BMT), heart, liver, spleen, lung, kidney, and muscle were harvested for biological analysis, after the GFP chimera model was established successfully, the same HA/β-TCP ceramic was implanted into both leg muscles of each mouse immediately after irradiation. 45 and 90 days after implantation, the ceramics of the two groups were harvested to perform with hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining; the results showed that there was no bone formation in group 2, while new bone tissues were detected in group 1. Our findings suggest that the BM cell from GFP transgenic mice is a good biomarker and it could set a good platform for chimera model; it also shows that BM cell is one of cell resources of bone induction, and destruction of immune function will impede osteoinduction by CP. Overall, our results may shed light on clear mechanism study of bone induction in the future.

  6. Structural characterization of anion-calcium-humate complexes in phosphate-based fertilizers.

    Science.gov (United States)

    Baigorri, Roberto; Urrutia, Oscar; Erro, Javier; Mandado, Marcos; Pérez-Juste, Ignacio; Garcia-Mina, José María

    2013-07-01

    Fertilizers based on phosphate-metal-humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid (31)P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the (31)P NMR peaks. Computational chemistry methods allowed the characterization of phosphate-calcium-humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate-calcium-humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate-metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental (31)P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the (31)P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate-calcium interactions within the crystals.

  7. Structural characterization of anion-calcium-humate complexes in phosphate-based fertilizers.

    Science.gov (United States)

    Baigorri, Roberto; Urrutia, Oscar; Erro, Javier; Mandado, Marcos; Pérez-Juste, Ignacio; Garcia-Mina, José María

    2013-07-01

    Fertilizers based on phosphate-metal-humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid (31)P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the (31)P NMR peaks. Computational chemistry methods allowed the characterization of phosphate-calcium-humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate-calcium-humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate-metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental (31)P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the (31)P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate-calcium interactions within the crystals. PMID:23670945

  8. Calcium Phosphate Glass-Ceramics for Biomedical Applications%生物医用钙磷酸盐微晶玻璃

    Institute of Scientific and Technical Information of China (English)

    李延报; Santos,TD; 等

    2001-01-01

    钙磷酸盐微晶玻璃因其具有生物活性、生物相容性,而广泛应用于牙科、骨科的替代及骨组织工程等领域。本文就钙磷酸盐微晶玻璃材料的制备工艺、组成性能、in vitro/vivo实验及医学应用作了较详细的评述。%Calcium phosphate glass-ceramics are widely applied in dental and bone repairing,substituting and bone tissue engineering because the glass-ceramics have good bioactivity and biocompatibility. In the present paper, processing of Ca phosphate glass-ceramics, the relations between compositions and properties, in vitro and in vivo behaviors of the glassceramics, and clinic applications were described in detail.

  9. Synthesis of some calcium phosphate crystals using the useful biomass for immobilization of microorganisms

    Science.gov (United States)

    Kohiruimaki, T.

    2011-10-01

    Three sources of biomass generated by primary industry were used as the raw material for the synthesis of calcium phosphate crystals. Phosphoric acid was extracted from burned rice chaff using a 30% nitric acid solution, while scallop shells and gypsum of plasterboard were used as calcium sources. The calcium phosphate crystals were synthesized by a method involving homogeneous precipitation, and the relationship between the composition and shape of the crystals and the pH at the time of the precipitation was investigated. Monetite crystals in a petal form with a diameter ranging from 0.1 to 2 μm were precipitated at pH 2.0, while granular apatite crystals with a mean diameter of 1 μm were precipitated at pH 6.0. We also investigated the ability of the synthesized calcium phosphate crystals to immobilize lactic acid bacteria for practical use in industrial bioreactor. It was determined that monetite crystals with a diameter of 2 μm had the highest ability to fix lactic acid bacteria. The population of lactic acid bacteria was estimated to exceed 1,300 bacteria per crystal surface of 50 μm2 suggesting that these crystals may be of practical use in industrial fermenters.

  10. Synthesis of some calcium phosphate crystals using the useful biomass for immobilization of microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Kohiruimaki, T, E-mail: kohi@hi-tech.ac.jp [Department of Technology, Hachinohe Institute of Technology, 88-1 Myo-oobiraki, Hachinohe-shi 031-8501 (Japan)

    2011-10-29

    Three sources of biomass generated by primary industry were used as the raw material for the synthesis of calcium phosphate crystals. Phosphoric acid was extracted from burned rice chaff using a 30% nitric acid solution, while scallop shells and gypsum of plasterboard were used as calcium sources. The calcium phosphate crystals were synthesized by a method involving homogeneous precipitation, and the relationship between the composition and shape of the crystals and the pH at the time of the precipitation was investigated. Monetite crystals in a petal form with a diameter ranging from 0.1 to 2 {mu}m were precipitated at pH 2.0, while granular apatite crystals with a mean diameter of 1 {mu}m were precipitated at pH 6.0. We also investigated the ability of the synthesized calcium phosphate crystals to immobilize lactic acid bacteria for practical use in industrial bioreactor. It was determined that monetite crystals with a diameter of 2 {mu}m had the highest ability to fix lactic acid bacteria. The population of lactic acid bacteria was estimated to exceed 1,300 bacteria per crystal surface of 50 {mu}m{sup 2} suggesting that these crystals may be of practical use in industrial fermenters.

  11. Investigation into the role of NaOH and calcium ions in the synthesis of calcium phosphate nanoshells

    Directory of Open Access Journals (Sweden)

    C. H. Yeo

    2012-03-01

    Full Text Available Calcium phosphate (CaP nanoshells were prepared using negatively charged liposomes (1,2-dioleoyl-sn-glycero-3-phosphate sodium salt (DOPA as a template by base titration synthesis at various concentrations of NaOH and calcium ions. The elemental composition, morphology, particle size, particle size distribution and zeta potential of the products were determined via various characterisation techniques, such as energy-dispersive X-ray spectrometry (EDX, transmission electron microscopy (TEM, dynamic light scattering (DLS, laser Doppler velocimetry (LDV and Fourier transform infrared spectroscopy (FTIR. The best results showed that stable spherical CaP nanoshells with a mean particle size of 197.5 ± 5.8 nm and a zeta potential of -34.5 ± 0.6 mV were successfully formed when 0.100 M sodium hydroxide (NaOH and 0.100 M calcium ions were used. Moreover, an optimal pH of 10.52 and a final Ca/P molar ratio of 0.97 were achieved under these conditions.

  12. Fifty years of human space travel: implications for bone and calcium research.

    Science.gov (United States)

    Smith, S M; Abrams, S A; Davis-Street, J E; Heer, M; O'Brien, K O; Wastney, M E; Zwart, S R

    2014-01-01

    Calcium and bone metabolism remain key concerns for space travelers, and ground-based models of space flight have provided a vast literature to complement the smaller set of reports from flight studies. Increased bone resorption and largely unchanged bone formation result in the loss of calcium and bone mineral during space flight, which alters the endocrine regulation of calcium metabolism. Physical, pharmacologic, and nutritional means have been used to counteract these changes. In 2012, heavy resistance exercise plus good nutritional and vitamin D status were demonstrated to reduce loss of bone mineral density on long-duration International Space Station missions. Uncertainty continues to exist, however, as to whether the bone is as strong after flight as it was before flight and whether nutritional and exercise prescriptions can be optimized during space flight. Findings from these studies not only will help future space explorers but also will broaden our understanding of the regulation of bone and calcium homeostasis on Earth.

  13. Bone mineralisation in premature infants cannot be predicted from serum alkaline phosphatase or serum phosphate

    DEFF Research Database (Denmark)

    Faerk, J; Peitersen, Birgit; Petersen, S;

    2002-01-01

    BACKGROUND: The bone mineral content of premature infants at term is lower than in mature infants at the same postconceptional age. Serum alkaline phosphatase and serum phosphate are often used as indicators of bone mineralisation. OBJECTIVE: To analyse the association between bone mineral content...... and serum alkaline phosphatase and serum phosphate. METHODS: Serum alkaline phosphatase and phosphate were measured at weekly intervals during admission in 108 premature infants of gestational age below 32 weeks (mean (SD) gestational age 29 (2) weeks; mean (SD) birth weight 1129 (279) g). Bone mineral...... content was measured at term (mean gestational age 41 weeks) by dual energy x ray absorptiometry and corrected for body size. RESULTS: Serum alkaline phosphatase was significantly negatively associated with serum phosphate (p alkaline...

  14. Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites

    Energy Technology Data Exchange (ETDEWEB)

    Nabiyouni, Maryam, E-mail: maryam.nabiyouni@rockets.utoledo.edu [Department of Bioengineering, University of Toledo, Toledo, OH (United States); Ren, Yufu [Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH (United States); Department of Surgery (Dentistry), University of Toledo, Toledo, OH (United States)

    2015-07-01

    As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg{sup +2} and Ca{sup +2} ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg{sup +2} and Ca{sup +2} ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg{sup +2}, calcium magnesium phosphates (CMPs) which release Mg{sup +2} and Ca{sup +2}, and hydroxyapatites (HAs) which release Ca{sup +2} were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7 days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg{sup +}2 and Ca{sup +2} ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts. - Highlights: • Role of Mg{sup 2

  15. Study of calcium phosphate (DCPD electrodeposition process on a Mg-3Al-1Zn magnesium alloy surface

    Directory of Open Access Journals (Sweden)

    Filip Pastorek

    2013-02-01

    Full Text Available Evaluation of calcium phosphating process realized on Mg-3Al-1Zn alloy surface after grinding was investigated by electrochemical tests supported by photodocumentation. The electrodeposition treatment was performed by electrochemical method in water solution of Ca(NO32.4H2O, (NH42HPO4 and H2O2. The formation of calcium phosphate was divided into several stages and described using light microscopy. The progress in corrosion protection of created calcium phosphate layer in 0.9% NaCl after particular electrodeposition steps was evaluated by electrochemical impedance spectroscopy. The results in the form of Nyquist plots were analyzed using equivalent circuits.

  16. Effects of dietary clinoptilolite and calcium levels on uric acid and calcium blood concentrations and bone quality of commercial layers

    Directory of Open Access Journals (Sweden)

    DA Berto

    2013-06-01

    Full Text Available The objective of the present study was to evaluate the effect of clinoptilolite and calcium levels on uric acid and calcium blood profile and bone quality of commercial layers. A total of 576 birds were distributed according to a completely randomized experimental design in a 3x4 factorial arrangement (calcium levels of 2.5, 3.1, or 3.7% and clinoptilolite levels of 0.0, 0.15, 0.25, or 0.50%, into 12 treatments with six replicates of eight birds per cage (experimental unit. The experimental period was 112 days. The experimental diets were based on corn and soybean meal. Results were submitted to analysis of variance and means were compared by the test of Tukey at 5% significance level using SISVAR statistical package. Blood uric acid was significantly influenced by the interaction of the evaluated factors. Clinoptilolite levels significantly increased blood calcium levels. There was no effect of dietary calcium levels on any of the evaluated characteristics. It was concluded that feeding layers with up to 0.50% clinoptilolite does not benefit blood uric acid and calcium concentrations and does not affect their bone quality. When layers at the end of the first laying cycle are fed ad libitum and present 119.50g/hen/day average feed intake, 3.1% dietary calcium promotes 3.7g/hen/day calcium intake, which is sufficient to maintain adequate calcium blood levels and bone quality.

  17. Microanalyses of the hydroxyl-poly-calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thin calcium phosphate coatings on titanium alloy substrates wereprepared by Ar+ ion beam assisted deposition (IBAD) from hydroxyl-poly-calciumsodium phosphate (HPPA) target. The coatings were analyzed by XRD, FTIR, XPS.These analyses revealed that the as-deposited films were amorphous or no apparentcrystallinity. No distinct absorption band of the hydroxyl group was observed in FTIRspectra of the coatings but new absorption bands were presented for CO3-2. Thecalcium to phosphorous ratio of these coatings in different IBAD conditions variedfrom 0.46 to 3.36.

  18. Calcium thorium phosphate (Whitlockite-type mineral). Synthesis and structure refinement

    International Nuclear Information System (INIS)

    The crystal structure of a new calcium thorium phosphate has been refined by the full-profile Rietveld method using X-ray powder diffraction data. The sample has been synthesized by the sol-gel technique. The phosphate has been identified by X-ray powder diffraction and IR spectroscopy. The refined composition is represented by the formula Ca10.26Th0.12(PO4)7. The CaOn and PO4 polyhedra are distorted compared to the corresponding polyhedra in the basic compound β-Ca3(PO4)2.

  19. Calcium phosphate/chitosan composite coating: Effect of different concentrations of Mg{sup 2+} in the m-SBF on its bioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Pharmacy College, Jiamusi University, Jiamusi 154007 (China); Dai, Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Wei, Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); School of Chemistry and Bioengineering, Suzhou Science Technology University, Suzhou 215009 (China); Wen, Zhaohui, E-mail: wenzhaohui1968@163.com [Department of neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zhang, Shujuan; Lin, Lemin [Department of neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

    2013-09-01

    The purpose of this study was to investigate the effect of different concentration of Mg{sup 2+} in a modified simulated body fluid (m-SBF) on the bioactivity of calcium phosphate/chitosan composite coating. Calcium phosphate/chitosan composite coating was prepared on graphite substrate via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The obtained samples were soaked in the m-SBF containing different concentration of Mg{sup 2+} for different times. And then, the composite coatings were assessed using X-ray diffractometer (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectra, and scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS). The soaking solution was evaluated by inductively coupled plasma optical emission spectrometer (ICP-OES) test. The analytical results showed that hydroxyapatite (HA) and bone-like apatite (HCA) grew on the surface of calcium phosphate/chitosan composite coating after incubation in different m-SBF. With Mg{sup 2+} concentration in m-SBF increased from 1× Mg to 10× Mg, HA in the composite coating first presented a dissolving process and then a precipitating one slowly, while HCA presented a growing trend, continuously. The increasing of Mg{sup 2+} concentration in the m-SBF inhibited the total growing process of HA and HCA as a whole. The structure of the composite coating changed from spherical into irregular morphology with the concentration of Mg{sup 2+} increasing from 1× Mg to 10× Mg. Over all, with the Mg{sup 2+} concentration increasing, the bioactivity of calcium phosphate/chitosan composite coating tended to decrease.

  20. Performance of functionally graded implants of polylactides and calcium phosphate/calcium carbonate in an ovine model for computer assisted craniectomy and cranioplasty.

    Science.gov (United States)

    Eufinger, Harald; Rasche, Christian; Lehmbrock, Jutta; Wehmöller, Michael; Weihe, Stephan; Schmitz, Inge; Schiller, Carsten; Epple, Matthias

    2007-01-01

    Biodegradable functionally graded skull implants on the basis of polylactides and calcium phosphate/calcium carbonate were prepared in an individual mould using a combination of different processing techniques. A geometrically corresponding resection template was designed to enable a craniectomy and cranioplasty with the prepared implant in the same operation. After various preliminary experiments concerning degradation kinetics, pH evolution during degradation, micromorphology, biocompatibility tests in human osteoblast cell cultures and surgery of cadaver heads, a new large-animal model was developed for long-term in vivo studies. In eight 12-months-old sheep, the surgical templates were used to create 4.5 x 5 cm(2) calvarial defects which were then filled with the corresponding degradable implants in the same operation. The animals were sacrificed after 2, 9, 12 and 18 months, and the implants and the surrounding tissues were analysed by computer tomography (CT), macroscopic examination and microscopy. The new animal model proved to be reliable and very suitable for large individual craniectomies and cranioplasties. The formation of new bone from the dural layer of the meninges corresponded well to the degradation of the porous inner layer of the implants whereas the skull contour was stabilised by the compact outer layer over the follow-up period.

  1. Phosphate Interacts With PTHrP to Regulate Endochondral Bone Formation

    OpenAIRE

    Liu, Eva S.; Zalutskaya, Alena; Chae, Byongsoo Timothy; Zhu, Eric D.; Gori, Francesca; Demay, Marie B.

    2014-01-01

    Phosphate and parathyroid hormone related peptide (PTHrP) are required for normal growth plate maturation. Hypophosphatemia impairs hypertrophic chondrocyte apoptosis leading to rachitic expansion of the growth plate; however, the effect of phosphate restriction on chondrocyte differentiation during endochondral bone formation has not been examined. Investigations were, therefore, undertaken to address whether phosphate restriction alters the maturation of embryonic d15.5 murine metatarsal el...

  2. Biomimetic coating of calcium phosphate on biometallic materials

    Institute of Scientific and Technical Information of China (English)

    ZHANG Er-lin; YANG Ke

    2005-01-01

    The biomimetic coating process in comparison with other processes is reviewed. This processing shows advantages in the surface bio-modification, such as low cost and flexible processing, wide range of apatite composition and thickness, non-line-of-sight characteristic and possibility to coat polymers and porous implants. The bio-mimetic apatite coating is made up of larger number of globules with size of 1-5μm. Each globule is a group of numerous flakes with a size range of 100-200nm to 30μm in length and 0.1-1μm in thickness. In-vitro and in-vivo studies show that the biomimetic apatite coating can promote an early and strong bonding to bone or promote the bone in-growth into the porous structure, which will be beneficial to the cementless stable fixation of orthopaedic implants. Recently developed co-precipitation of a kind of protein molecules into the HA coating shows much promising.

  3. Dissolution of the inorganic phase of bone leading to release of calcium regulates osteoclast survival

    DEFF Research Database (Denmark)

    Nielsen, Rasmus H; Karsdal, Morten A; Sørensen, Mette G;

    2007-01-01

    Osteoclasts are the sole cells possessing the ability to resorb calcified bone matrix. This occurs via secretion of hydrochloric acid mediated by the V-ATPase and the chloride channel ClC-7. Loss of acidification leads to osteopetrosis characterized by ablation of bone resorption and increased...... osteoclast numbers, indicating increased life span of the osteoclasts. To investigate the role of the inorganic phase of bone with respect to osteoclast life span, we used the V-ATPase inhibitor bafilomycin and the calcium uptake antagonist ryanodine on human osteoclasts cultured on calcified and decalcified...... bone slices. Bafilomycin inhibited bone resorption and increased osteoclast survival on calcified but not decalcified bones. Ryanodine attenuated calcium uptake and thereby augmented osteoclast survival on calcified bones. In summary, we found that acidification leading to calcium release from bone...

  4. Preparation and Properties of Nanoparticles of Calcium Phosphates With Various Ca/P Ratios.

    Science.gov (United States)

    Sun, Limin; Chow, Laurence C; Frukhtbeyn, Stanislav A; Bonevich, John E

    2010-01-01

    This study aimed at preparing and studying the properties of nanoparticles of calcium phosphate (nCaP) with Ca/P ratios ranging from 1.0 to 1.67 using a spray-drying technique. Micro-structural analyses suggested that the nCaPs with Ca/P ratios of 1.67 to 1.33 were nano-sized amorphous calcium phosphate (ACP) containing varying amounts of acid phosphate and carbonate. The nCaP with Ca/P ratio of 1 contained only nano-sized low crystalline dicalcium phosphate (DCP). BET measurements of the nCaPs showed specific surface areas of (12 ± 2 to 50 ± 1) m(2)/g, corresponding to estimated equivalent spherical diameters of (38 to 172) nm. However, dynamic light scattering measurements revealed much larger particles of (380 ± 49 to 768 ± 111) nm, owing to agglomeration of the smaller primary nano particles as revealed by Scanning Electron Microscopy (SEM). Thermodynamic solubility measurements showed that the nCaPs with Ca/P ratio of 1.33 - 1.67 all have similar solubility behavior. The materials were more soluble than the crystalline hydroxyapatite (HA) at pH greater than about 4.7, and more soluble than β-tricalcium phosphate (β-TCP), octacalcium phosphate (OCP) and DCP at pH above 5.5. Their solubility approached that of α-tricalcium phosphate (α-TCP) at about pH 7. These nCaPs, which cannot be readily prepared by other currently available methods for nanoparticle preparation, have potential biomedical applications.

  5. Effect of nano-hydroxyapatite coating on the osteoinductivity of porous biphasic calcium phosphate ceramics

    Science.gov (United States)

    2014-01-01

    Background Porous biphasic calcium phosphate (BCP) ceramics exhibit good biocompatibility and bone conduction but are not inherently osteoinductive. To overcome this disadvantage, we coated conventional porous BCP ceramics with nano-hydroxyapatite (nHA). nHA was chosen as a coating material due to its high osteoinductive potential. Methods We used a hydrothermal deposition method to coat conventional porous BCP ceramics with nHA and assessed the effects of the coating on the physical and mechanical properties of the underlying BCP. Next, its effects on mesenchymal stem cell (MSC) attachment, proliferation, viability, and osteogenic differentiation were investigated. Results nHA formed a deposited layer on the BCP surface, and synthesized nHA had a rod-like shape with lengths ranging from ~50–200 nm and diameters from ~15–30 mm. The nHA coating did not significantly affect the density, porosity, flexural strength, or compressive strength of the underlying BCP (P > 0.1). Scanning electron microscopy showed MSC attachment to the scaffolds, with a healthy morphology and anchorage to nHA crystals via cytoplasmic processes. The densities of MSCs attached on BCP and nHA-coated BCP scaffolds were 62 ± 26 cells/mm2 and 63 ± 27 cells/mm2 (P > 0.1), respectively, after 1 day and 415 ± 62 cells/mm2 and 541 ± 35 cells/mm2 (P < 0.05) respectively, after 14 days. According to an MTT assay, MSC viability was higher on nHA-coated BCP scaffolds than on BCP scaffolds (P < 0.05). In addition, MSCs on nHA-coated BCP scaffolds produced more alkaline phosphatase, collagen type I, and osteocalcin than MSCs on BCP scaffolds (P < 0.05). Conclusions Our results demonstrate that BCP scaffolds coated with nHA were more conducive for MSC adhesion, proliferation, and osteogenic differentiation than conventional, uncoated BCP scaffolds, indicating that nHA coating can enhance the osteoinductive potential of BCP ceramics, making this material more

  6. Enhanced Osteogenic and Vasculogenic Differentiation Potential of Human Adipose Stem Cells on Biphasic Calcium Phosphate Scaffolds in Fibrin Gels

    Science.gov (United States)

    2016-01-01

    For bone tissue engineering synthetic biphasic calcium phosphate (BCP) with a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ratio of 60/40 (BCP60/40) is successfully clinically applied, but the high percentage of HA may hamper efficient scaffold remodelling. Whether BCP with a lower HA/β-TCP ratio (BCP20/80) is more desirable is still unclear. Vascular development is needed before osteogenesis can occur. We aimed to test the osteogenic and/or vasculogenic differentiation potential as well as degradation of composites consisting of human adipose stem cells (ASCs) seeded on BCP60/40 or BCP20/80 incorporated in fibrin gels that trigger neovascularization for bone regeneration. ASC attachment to BCP60/40 and BCP20/80 within 30 min was similar (>93%). After 11 days of culture BCP20/80-based composites showed increased alkaline phosphatase activity and DMP1 gene expression, but not RUNX2 and osteonectin expression, compared to BCP60/40-based composites. BCP20/80-based composites also showed enhanced expression of the vasculogenic markers CD31 and VEGF189, but not VEGF165 and endothelin-1. Collagen-1 and collagen-3 expression was similar in both composites. Fibrin degradation was increased in BCP20/80-based composites at day 7. In conclusion, BCP20/80-based composites showed enhanced osteogenic and vasculogenic differentiation potential compared to BCP60/40-based composites in vitro, suggesting that BCP20/80-based composites might be more promising for in vivo bone augmentation than BCP60/40-based composites.

  7. Enhanced Osteogenic and Vasculogenic Differentiation Potential of Human Adipose Stem Cells on Biphasic Calcium Phosphate Scaffolds in Fibrin Gels

    Science.gov (United States)

    2016-01-01

    For bone tissue engineering synthetic biphasic calcium phosphate (BCP) with a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ratio of 60/40 (BCP60/40) is successfully clinically applied, but the high percentage of HA may hamper efficient scaffold remodelling. Whether BCP with a lower HA/β-TCP ratio (BCP20/80) is more desirable is still unclear. Vascular development is needed before osteogenesis can occur. We aimed to test the osteogenic and/or vasculogenic differentiation potential as well as degradation of composites consisting of human adipose stem cells (ASCs) seeded on BCP60/40 or BCP20/80 incorporated in fibrin gels that trigger neovascularization for bone regeneration. ASC attachment to BCP60/40 and BCP20/80 within 30 min was similar (>93%). After 11 days of culture BCP20/80-based composites showed increased alkaline phosphatase activity and DMP1 gene expression, but not RUNX2 and osteonectin expression, compared to BCP60/40-based composites. BCP20/80-based composites also showed enhanced expression of the vasculogenic markers CD31 and VEGF189, but not VEGF165 and endothelin-1. Collagen-1 and collagen-3 expression was similar in both composites. Fibrin degradation was increased in BCP20/80-based composites at day 7. In conclusion, BCP20/80-based composites showed enhanced osteogenic and vasculogenic differentiation potential compared to BCP60/40-based composites in vitro, suggesting that BCP20/80-based composites might be more promising for in vivo bone augmentation than BCP60/40-based composites. PMID:27547223

  8. Enhanced Osteogenic and Vasculogenic Differentiation Potential of Human Adipose Stem Cells on Biphasic Calcium Phosphate Scaffolds in Fibrin Gels.

    Science.gov (United States)

    van Esterik, Fransisca A S; Zandieh-Doulabi, Behrouz; Kleverlaan, Cornelis J; Klein-Nulend, Jenneke

    2016-01-01

    For bone tissue engineering synthetic biphasic calcium phosphate (BCP) with a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ratio of 60/40 (BCP60/40) is successfully clinically applied, but the high percentage of HA may hamper efficient scaffold remodelling. Whether BCP with a lower HA/β-TCP ratio (BCP20/80) is more desirable is still unclear. Vascular development is needed before osteogenesis can occur. We aimed to test the osteogenic and/or vasculogenic differentiation potential as well as degradation of composites consisting of human adipose stem cells (ASCs) seeded on BCP60/40 or BCP20/80 incorporated in fibrin gels that trigger neovascularization for bone regeneration. ASC attachment to BCP60/40 and BCP20/80 within 30 min was similar (>93%). After 11 days of culture BCP20/80-based composites showed increased alkaline phosphatase activity and DMP1 gene expression, but not RUNX2 and osteonectin expression, compared to BCP60/40-based composites. BCP20/80-based composites also showed enhanced expression of the vasculogenic markers CD31 and VEGF189, but not VEGF165 and endothelin-1. Collagen-1 and collagen-3 expression was similar in both composites. Fibrin degradation was increased in BCP20/80-based composites at day 7. In conclusion, BCP20/80-based composites showed enhanced osteogenic and vasculogenic differentiation potential compared to BCP60/40-based composites in vitro, suggesting that BCP20/80-based composites might be more promising for in vivo bone augmentation than BCP60/40-based composites. PMID:27547223

  9. Effect of dietary calcium: Phosphorus ratio on bone mineralization and intestinal calcium absorption in ovariectomized rats.

    Science.gov (United States)

    Koshihara, Moyuru; Masuyama, Ritsuko; Uehara, Mariko; Suzuki, Kazuharu

    2004-01-01

    We investigated the effect of dietary calcium:phosphorus (Ca:P) ratio on bone mineralization and intestinal Ca absorption in ovariectomized (OVX) rat models of osteoporosis and sham-operated rats. Thirty 12-wk-old female Wistar rats were divided into three groups of OVX rats and three groups of sham rats. Thirty days after the adaptation period, OVX rats and sham rats were fed a diet formulated Ca:P, 1:0.5, 1:1 or 1:2 (each diet containing 0.5% Ca), respectively for 42 d. In both sham and OVX rats, serum osteocalcin, a marker of bone turnover, was increased by decreasing Ca:P ratio (1:2). In contrast, rats fed the Ca:P = 1:0.5 diet (dietary P restriction) suppressed the increased serum parathyroid hormone, osteocalcin and urinary deoxypyridinoline, and increased Ca absorption in both sham and OVX rats compared to the Ca:P = 1:1 and 1:2 diets. Especially, in OVX rats, the decreased bone mineral density of the fifth lumbar was also suppressed when rats were fed the Ca:P = 1:0.5 diet. These results indicated that the elevation of dietary Ca:P ratio may inhibit bone loss and increase intestinal Ca absorption in OVX rats.

  10. Adolescence: How do we increase intestinal calcium absorption to allow for bone mineral mass accumulation?

    Science.gov (United States)

    An increase in calcium absorptive efficiency (fractional absorption of dietary calcium) during adolescence is associated with a rapid increase in total body bone mineral mass (BMM) accumulation. This increase occurs across a range of calcium intakes. It appears to be principally mediated by hormonal...

  11. In vitro degradation and cell response of calcium carbonate composite ceramic in comparison with other synthetic bone substitute materials

    Energy Technology Data Exchange (ETDEWEB)

    He, Fupo [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China); Zhang, Jing [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Yang, Fanwen; Zhu, Jixiang; Tian, Xiumei [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China); Chen, Xiaoming, E-mail: xmchenw@126.com [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China)

    2015-05-01

    The robust calcium carbonate composite ceramics (CC/PG) can be acquired by fast sintering calcium carbonate at a low temperature (650 °C) using a biocompatible, degradable phosphate-based glass (PG) as sintering agent. In the present study, the in vitro degradation a