Biphasic calcium phosphate (BCP) nanopowders were synthesized by using microwave and non-microwave irradiation assisted processes. The synthesized powders were pressed under a pressure of 90 MPa, and then were sinte...Biphasic calcium phosphate (BCP) nanopowders were synthesized by using microwave and non-microwave irradiation assisted processes. The synthesized powders were pressed under a pressure of 90 MPa, and then were sintered at 1000-1200℃ for 1 h. The mechanical properties of the samples were investigated. The formed phases and microstructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the synthesis time was shorter, along with a more homogeneous microstructure, when the microwave irradiation assisted method was applied. The compression strength and the Young's modulus of the samples synthesized with microwave irradiation were about 60 MPa and 3 GPa, but those of the samples synthesized without microwave irradiation were about 30 MPa and 2 GPa, respectively. XRD patterns of the microwave irradiation assisted and non-microwave irradiation assisted nanopowders showed the coexistence of hydroxyapatite (HA) and lricalcium phosphate (TCP) phases in the system.展开更多
The phosphate solubilizing characteristics of a strain YC, which was isolated from phosphate mines (Hubei, China), were studied in National Botanical Research Institute’s phosphate (NBRIP) growth medium containing tr...The phosphate solubilizing characteristics of a strain YC, which was isolated from phosphate mines (Hubei, China), were studied in National Botanical Research Institute’s phosphate (NBRIP) growth medium containing tricalcium phosphate (TCP) as sole phosphorus (P) source. The strain YC is identified as Stenotrophomonas maltophilia (S. maltophilia) based upon the results of morphologic, physiological and biochemical characteristics and 16S rRNA sequences analysis. The results show that the strain S. maltophilia YC can solubilize TCP and release soluble P in NBRIP growth medium. A positive correlation between concentration of soluble P and population of the isolate and a negative correlation between concentration of soluble P and pH in the culture medium are observed from statistical analysis results. Moreover, gluconic acid is detected in the culture medium by HPLC analysis. It indicates that the isolate can release gluconic acid during the solubilizing experiment, which causes acidification of the culture medium and then TCP solubilization. S. maltophilia YC has a maximal TCP solubilizing capability when using maltose as carbon source and ammonium nitrate as nitrogen source, respectively, in NBRIP growth medium.展开更多
Biphasic calcium phosphate (BCP) consisting of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) was successfully synthesized by new hydrothermal route using β-TCP as precursor. The X-ray diffraction analysis ...Biphasic calcium phosphate (BCP) consisting of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) was successfully synthesized by new hydrothermal route using β-TCP as precursor. The X-ray diffraction analysis of as-synthesized powder indicated that β-TCP had been transformed into HA phase and amount of HA formed gradually increased with prolonged time. The results revealed that the recent technique may be able to control the composition of the obtained BCP which would influence the bioresorbability. Porous body of BCP was prepared by impregnation of polymeric sponge template with the slurry of the powder followed by sintering. The X-ray diffraction of porous product revealed that the composition of β-TCP increased after sintering indicating that HA had been decomposed. Porous BCP obtained from the recent technique possessed both macro and micropores structure which are useful for rapid tissue formation. Besides, the recent porous fabrication technique yielded porous BCP which preserved the sponge template morphology, enabling it to fabricate porous material with controlled pores structure.展开更多
Current calcium phosphate ( CaP ) biomaterials for bone repair, substitution, augmentation and regeneration include hydroxyapatite ( HA ) from synthetic or biologic origin, beta-tricaicium phosphate ( β- TCP ),...Current calcium phosphate ( CaP ) biomaterials for bone repair, substitution, augmentation and regeneration include hydroxyapatite ( HA ) from synthetic or biologic origin, beta-tricaicium phosphate ( β- TCP ), biphasic calcium phosphate (BCP), and are available as granules, porous blocks, components of compashes (CaP/pollymer) 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.展开更多
Porous β-tricalcium phosphate bioceramic (PTCP) has important roles in surgical implants because of good biocompatibility. But the low compressive strength of the ceramic limits its application. The preparation of ...Porous β-tricalcium phosphate bioceramic (PTCP) has important roles in surgical implants because of good biocompatibility. But the low compressive strength of the ceramic limits its application. The preparation of PTCP was improved with the adjustment of the constituents and the sintering-process. A new type of PTCP material with high compressive strength was made. The compositions, microstructure and properties of PTCP were analyzed by TG-DSC, XRD, TEM, SEM and so on. The result indicates that stearic acid burns sufficiently and gives out carbon dioxide and water vapor when slowly heated between 200 ℃ and 400 ℃ so that the porous structure like coral in β-TCP bioceramic is formed. Through crystallization at 470 ℃ and 570 ℃, more CaO-P2O5 glass-cement is converted into crystallite-glass, which is beneficial for improving the compressive strength of β-TCP bioceramic. PTCP can form a support action in bone imperfect section with good solubility.展开更多
种子细胞、支架材料及二者的相互作用是骨组织工程需要解决的三大问题。骨髓间充质干细胞(Mesenchym al stem cells,MSCs)是一种很有潜力的种子细胞,但挑选什么样的MSCs作为种子细胞目前研究尚少;而材料方面,研制力学性能和生物相容性...种子细胞、支架材料及二者的相互作用是骨组织工程需要解决的三大问题。骨髓间充质干细胞(Mesenchym al stem cells,MSCs)是一种很有潜力的种子细胞,但挑选什么样的MSCs作为种子细胞目前研究尚少;而材料方面,研制力学性能和生物相容性均好的可降解多孔支架材料一直是研究者努力的方向。为了挑选处于最佳时期的种子细胞以及最适比例的β- TCP/PL L A多孔支架材料,我们观察并检测了大鼠MSCs(r MSCs)成骨诱导后不同时期细胞的形态及功能,发现r MSCs成骨诱导后10 d左右开始进入增殖期,14 d左右进入基质合成期,2 0 d左右进入矿化结节期(但三者不是截然分开的) ,从而根据实验目的挑选出能作为骨组织工程用的最佳细胞。将该时期的种子细胞与不同比例的β- TCP/PL L A多孔支架材料复合后,通过荧光显微镜、扫描电镜以及MTT等方法初步比较了不同比例的材料对细胞生长状况的影响,结果显示不同比例的材料均具有一定的生物相容性,细胞生长良好。但以β- TCP/PL L A=2∶1的材料最好,对细胞的生长影响最小。展开更多
To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared ...To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solventcasting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behaviorof the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP,the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporatedinto the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold weredetermined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Resultsshow that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strengthneeded for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility andosteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation andosteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It isexpected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.展开更多
文摘Biphasic calcium phosphate (BCP) nanopowders were synthesized by using microwave and non-microwave irradiation assisted processes. The synthesized powders were pressed under a pressure of 90 MPa, and then were sintered at 1000-1200℃ for 1 h. The mechanical properties of the samples were investigated. The formed phases and microstructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the synthesis time was shorter, along with a more homogeneous microstructure, when the microwave irradiation assisted method was applied. The compression strength and the Young's modulus of the samples synthesized with microwave irradiation were about 60 MPa and 3 GPa, but those of the samples synthesized without microwave irradiation were about 30 MPa and 2 GPa, respectively. XRD patterns of the microwave irradiation assisted and non-microwave irradiation assisted nanopowders showed the coexistence of hydroxyapatite (HA) and lricalcium phosphate (TCP) phases in the system.
基金Project(2004CB619201) supported by the Major State Basic Research and Development Program of ChinaProject(Z200515002) supported by the Key Project Foundation of the Education Department of Hubei Province, China+1 种基金Project(GCP200801) supported by the Open Research Fund of Key Laboratory for Green Chemical Process of Ministry of Education, ChinaProject(Q200811) supported by the Youths Science Foundation of Wuhan Institute of Technology, China
文摘The phosphate solubilizing characteristics of a strain YC, which was isolated from phosphate mines (Hubei, China), were studied in National Botanical Research Institute’s phosphate (NBRIP) growth medium containing tricalcium phosphate (TCP) as sole phosphorus (P) source. The strain YC is identified as Stenotrophomonas maltophilia (S. maltophilia) based upon the results of morphologic, physiological and biochemical characteristics and 16S rRNA sequences analysis. The results show that the strain S. maltophilia YC can solubilize TCP and release soluble P in NBRIP growth medium. A positive correlation between concentration of soluble P and population of the isolate and a negative correlation between concentration of soluble P and pH in the culture medium are observed from statistical analysis results. Moreover, gluconic acid is detected in the culture medium by HPLC analysis. It indicates that the isolate can release gluconic acid during the solubilizing experiment, which causes acidification of the culture medium and then TCP solubilization. S. maltophilia YC has a maximal TCP solubilizing capability when using maltose as carbon source and ammonium nitrate as nitrogen source, respectively, in NBRIP growth medium.
文摘Biphasic calcium phosphate (BCP) consisting of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) was successfully synthesized by new hydrothermal route using β-TCP as precursor. The X-ray diffraction analysis of as-synthesized powder indicated that β-TCP had been transformed into HA phase and amount of HA formed gradually increased with prolonged time. The results revealed that the recent technique may be able to control the composition of the obtained BCP which would influence the bioresorbability. Porous body of BCP was prepared by impregnation of polymeric sponge template with the slurry of the powder followed by sintering. The X-ray diffraction of porous product revealed that the composition of β-TCP increased after sintering indicating that HA had been decomposed. Porous BCP obtained from the recent technique possessed both macro and micropores structure which are useful for rapid tissue formation. Besides, the recent porous fabrication technique yielded porous BCP which preserved the sponge template morphology, enabling it to fabricate porous material with controlled pores structure.
文摘Current calcium phosphate ( CaP ) biomaterials for bone repair, substitution, augmentation and regeneration include hydroxyapatite ( HA ) from synthetic or biologic origin, beta-tricaicium phosphate ( β- TCP ), biphasic calcium phosphate (BCP), and are available as granules, porous blocks, components of compashes (CaP/pollymer) 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.
文摘Porous β-tricalcium phosphate bioceramic (PTCP) has important roles in surgical implants because of good biocompatibility. But the low compressive strength of the ceramic limits its application. The preparation of PTCP was improved with the adjustment of the constituents and the sintering-process. A new type of PTCP material with high compressive strength was made. The compositions, microstructure and properties of PTCP were analyzed by TG-DSC, XRD, TEM, SEM and so on. The result indicates that stearic acid burns sufficiently and gives out carbon dioxide and water vapor when slowly heated between 200 ℃ and 400 ℃ so that the porous structure like coral in β-TCP bioceramic is formed. Through crystallization at 470 ℃ and 570 ℃, more CaO-P2O5 glass-cement is converted into crystallite-glass, which is beneficial for improving the compressive strength of β-TCP bioceramic. PTCP can form a support action in bone imperfect section with good solubility.
文摘种子细胞、支架材料及二者的相互作用是骨组织工程需要解决的三大问题。骨髓间充质干细胞(Mesenchym al stem cells,MSCs)是一种很有潜力的种子细胞,但挑选什么样的MSCs作为种子细胞目前研究尚少;而材料方面,研制力学性能和生物相容性均好的可降解多孔支架材料一直是研究者努力的方向。为了挑选处于最佳时期的种子细胞以及最适比例的β- TCP/PL L A多孔支架材料,我们观察并检测了大鼠MSCs(r MSCs)成骨诱导后不同时期细胞的形态及功能,发现r MSCs成骨诱导后10 d左右开始进入增殖期,14 d左右进入基质合成期,2 0 d左右进入矿化结节期(但三者不是截然分开的) ,从而根据实验目的挑选出能作为骨组织工程用的最佳细胞。将该时期的种子细胞与不同比例的β- TCP/PL L A多孔支架材料复合后,通过荧光显微镜、扫描电镜以及MTT等方法初步比较了不同比例的材料对细胞生长状况的影响,结果显示不同比例的材料均具有一定的生物相容性,细胞生长良好。但以β- TCP/PL L A=2∶1的材料最好,对细胞的生长影响最小。
基金This study was financially supported by 863 Hj-Tech ResearchDevelopment Program of China(2002AA326080)The Fund for Youth Teacher of Education Mlinistry of China(2002123).
文摘To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solventcasting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behaviorof the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP,the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporatedinto the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold weredetermined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Resultsshow that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strengthneeded for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility andosteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation andosteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It isexpected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.