多糖基纳米复合支架的仿生构建及性能研究

Biomimetic Preparation and Characterization of Polysaccharides Based Nano-Hydroxyapatite Composite Scaffold

以多糖(ChS/CSA/HYA)为有机模板,可溶性钙/磷酸盐为nHAP前驱体,采用仿生合成和冷冻干燥技术构建纳米(nHAP)-微米(微米级孔径)-宏观(支架)多级结构的ChS/CSA/HYA/nHAP纳米复合支架,并探究其性能。结果表明:支架具有相互连通的多孔结构,孔径大小为45~156μm,孔隙率为(93.78±1.56)%;原位形成的弱结晶nHAP赋予支架良好的矿化活性;支架的抗压强度为(0.126±0.073)MPa,弹性模量为(0.682±0.045)MPa,可基本满足非负重部位骨缺损修复要求。MTT检测结果显示支架对细胞增殖基本无抑制作用,相对安全无毒。

Chitosan(ChS), Chondroitin Sulfate A(CSA) and Hyaluronic Acid(HYA) were employed as organic matrix, while calcium and phosphate salt solution were the precursors of the inorganic phase. The novel ChS/CSA/HYA/nHAP nano-composite scaffold with multilevel structure(nano-micron-macro) were prepared, using the biomimetic synthesis and freeze-drying technique. SEM shows that the composite scaffold possesses interconnected porous structure, with the pore size of 45~156 μm and porosity at(93.78±1.56)%. The nano-particles were formed in situ with relatively homogeneous distribution in the scaffold. XRD and FTIR confirm the scaffold in situ forms nano-HAP crystals. ChS/CSA/HYA/nHAP nano-composite scaffold has relative good mechanical properties with compressive strength of(0.126±0.073) MPa and elastic modulus of(0.682±0.045) MPa. Rat osteoblast was used to set up in vitro evaluation model. The MTT measurement shows the cytotoxicity grade of the scaffold is 0 to 1, which indicates that the ChS/CSA/HYA/nHAP nano-composite scaffold has relative good cytocompatibility. All the results show that the ChS/CSA/ HYA/nHAP nano-composite scaffold may serve as a good scaffold for bone tissue engineering.