Effects of Quenching Temperature and Time on Pore Diameter of Poly（3-hydroxybutyrate-co-3-hydroxyhexanoate） Porous Scaffolds and MC3T3-E1 Osteoblast Response to the Scaffolds

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) scaffolds were prepared by thermally inducing phase separation (TIPS) for bone reconstruction. Scanning electron microscopy and porosity measurements were used to analyze the structure and properties of the scaffolds. The pore diameter of the scaffolds could be easily controlled by changing the quenching temperature and time. The biocompatibility was assessed by examining the proliferation and morphology of MC 3T3-E1 osteoprogenitor cells seeded on the scaffolds. Cultures grown in the presence of a source of phosphate ions showed the formation of a mineralized extracellular matrix. The results indicate that PHBHHx scaffolds prepared using TIPS are a promising candidate for bone reconstruction.     

3D Nanocomposite Hydrogel Scaffolds Fabricated by Rapid Prototyping for Bone Tissue Engineering

Colloidal gels made of oppositely charged nanoparticles are a novel class of hydrogels and can exhibit pseudoplastic behavior which will enable them to mold easily into specific shapes. These moldable gels can be used as building blocks to self-assemble into integral scaffolds from bottom to up through electrostatic forces. However, they are too weak to maintain scaffold morphology just depending on interparticle interactions such as Van der Waals attraction and electrostatic forces especially for bone tissue engineering. In this study, oppositely charged gelatin nanoparticles were firstly prepared by two-step desolvation method, followed by the mixture with water to form colloid gels. To solve the problem of weak mechanical performance of colloid gels, gelatin macromolecules were introduced into the prepared gels to form blend gels. The blend gels can be easily processed into three-dimensional （3D） porous scaffolds via motor assisted microsyringe （MAM） system, a nozzle-based rapid prototyping technology, under mild conditions. After fabrication the scaffolds were erosslinked by glutaraldehyde （ GA, 25 % solution in water by weight）, then the crosslinked gelatin macromolecules network could form to improve the mechanical properties of colloid gels. The average particle size and zeta potential of gdatin nanoparticles were measured by Nano- ZS instrument. The morphology and microstructures of scaffolds were characterized by macroscopic images. The mechanical properties of the scaffolds were studied by a universal material testing machine.     

生物医用聚乳酸纤维增强壳聚糖棒材

利用原位沉析法制备了聚乳酸纤维/壳聚糖复合棒材,对复合棒材的微观形貌、力学性能进行了表征.有机聚乳酸纤维和有机壳聚糖基体具有良好的相容性,纤维表面还会因氢键等作用和基体产生物理吸附及一定的分子链缠结,SEM结果表明,纤维与基体间形成了良好的界面作用.复合棒材因聚乳酸纤维的加入有效地提高了弯曲强度和模量.当添加8%(质量分数)11 mm长的纤维时,复合材料弯曲强度达到108.9 MPa,比壳聚糖提高了54.9%,复合棒材弯曲模量达到4.74 GPa,比壳聚糖提高了170.9%.聚乳酸纤维和壳聚糖均具有良好的生物相容性和可降解性,这种复合材料在可吸收内固定材料方面将具有广阔的用途.     

利塞膦酸盐对磷硅酸钙理化及生物性能的影响

将利塞膦酸盐(0.5%和1.0%)与含有磷硅酸钙的骨水泥粉末混合后进行水化反应,测定骨水泥固化时间及抗压强度,并分析其载药前后的微观结构变化.通过细胞毒性与基因表达水平检测分析了骨水泥的生物性能.结果表明:在0.5%药物水平下,骨水泥促进成骨细胞增殖与分化效果最佳.药物可延缓骨水泥固化,但骨水泥的气孔率会随之降低且晶体结构会更加紧密.载有利塞膦酸的磷硅酸钙骨水泥具有与松质骨相似的力学强度及良好的生物相容性,作为骨组织修复材料具有很好的应用价值.     

骨髓间充质干细胞三维培养--构建工程组织

骨髓间充质干细胞因其可获得性、可扩增性和可多向分化性,是理想的组织工程种子细胞,用于构建工程组织。实现这一目标的主要障碍在于如何在体外模拟生理环境培养骨髓间充质干细胞,因此,研究并改进骨髓间充质干细胞体外三维培养至关重要。对近年来骨髓间充质干细胞作为组织工程种子细胞的培养方式、培养系统以及培养中的环境因素加以评述。     

老年人退化性骨质疏松及其防治

论述了老年退化性骨质疏松的临床特点、发病原因及防治措施。     

成人骨髓基质细胞的体外培养

本研究从成人的髋骨抽取骨髓液，离心后将骨髓基质细胞悬液接种培养，待细胞贴壁融合后，进行传代扩增培养．并采用流式细胞术进行细胞周期分析，结果表明原代培养和传代培养的细胞均为贴壁、形态不一的骨髓基质细胞，且此体外培养的骨髓基质细胞具有很强的增殖能力．本研究成功地建立了一套完整、简单、可行的体外分离、长期培养扩增人骨髓基质细胞(Human Bone Marrow Stromal Cells hBMSCs)的系统，证明成人骨髓基质细胞能够在体外长期增殖，为人的骨髓基盾细胞的理论研究和临床应用奠定了基础.     

帕米磷酸二钠治疗绝经后骨质疏松症患者的临床疗效观察

目的观察帕米磷酸二钠防治绝经后骨质疏松症患者的疗效。方法将63例绝经后骨质疏松症患者随机分为两组,对照组采用口服凯思立D、罗盖全和仙灵骨葆胶囊治疗,治疗组采用静滴帕米磷酸二钠和口服凯思立D、罗盖全、仙灵骨葆胶囊治疗,分别治疗6个月。在治疗前、治疗1个月、3个月、6个月分别进行VAS疼痛评分,以及治疗前、治疗6个月进行腰椎L1-4骨密度(BMD)检测。结果治疗1个月和3个月,两组VAS评分较治疗前有不同程度降低,且治疗组止痛效果优于对照组(P0.05);治疗6个月,两组VAS评分均明显降低,但两组VAS评分无统计学差异(P0.05)。治疗6个月,两组腰椎L1-4骨密度较治疗前明显提高(P0.05),且治疗组优于对照组(P0.05)。结论帕米磷酸二钠可有效缓解绝经后骨质疏松症患者的疼痛,并且能提高患者的骨密度。     

Calcium carbonate nanoparticles promote osteogenesis compared to adipogenesis in human bone-marrow mesenchymal stem cells

Rhombohedron-like and fusiform calcium carbonate nanoparticles were fabricated using a new method. Their geometry was controlled by varying the mixing speed and ratio of ethanol versus water in reaction system. The calcium carbonate nanoparticles(CCNPs) have slight effect on viability of human bone-marrow mesenchymal stem cells(hBMSCs) with dose-dependent and shape-dependent, but they can significantly promote osteogenic differentiation of hBMSCs in vitro by 10–37% increase of alkaline phosphatase(ALP) activity, 9–36% growth of collagen secretion and 1.13–1.83 folds upregulation of osteogenesis-related genes, even at lower dose ranges(5–20 μg/ml). The efficacity of promoting osteogenesis depends on the shape and dose of CCNPs. Furthermore,adipogenesis was inhibited by less accumulation of lipid droplets, lower triglyceride(TG) secretion and downregulation of adipogenesis-related genes. These findings improve the understanding of effects CCNPs on hBMSCs fate towards osteoblasts or adipocytes and have meaningful impact for combining use of CCNPs and hBMSCs in tissue engineering and regenerative medicine fields.