胶原/生物活性玻璃/壳聚糖增强型复合支架

背景：生物活性玻璃/胶原复合材料具有优良的成骨活性和的生物学性能，然而其在人体环境中易降解而导致支架溃散、力学性能下降。目的：构建具有良好力学性能、抗降解性能和骨修复特性的胶原/生物活性玻璃/壳聚糖增强型复合支架。方法：以壳聚糖作为分散剂，将生物活性玻璃粉体预先在壳聚糖溶液中均匀分散，然后与胶原溶液混合，结合冷冻干燥法制备多孔胶原/生物活性玻璃/壳聚糖增强型复合骨修复支架。采用傅里叶变换红外光谱仪、场发射扫描电子显微镜、X射线衍射仪、动态生物力学试验机等对复合支架的结构和性能进行表征。结果与结论：由于壳聚糖和生物活性玻璃粉体在微酸性环境下的电荷吸引，使在壳聚糖中预分散的生物活性玻璃颗粒在复合支架中分散更均匀；壳聚糖的引入大量增加了机体中的羟基和氨基，使分子间的相互作用增强，显著提高了材料的抗压模量和强度；壳聚糖和胶原在分子尺度的混合，使胶原分子被壳聚糖包裹，降低了胶原酶对胶原分子的酶切能力，显著提高了复合支架的抗胶原酶解性；壳聚糖分子使生物活性玻璃颗粒更均匀的包裹在大分子基相中，减少了生物活性玻璃颗粒的团聚和暴露，导致复合支架在模拟体液中的矿化活性略微降低。

Collagen/bioactive glass/chitosan composite scaffolds

BACKGROUND：Col agen/bioactive glass composite materials possess excellent osteogenic potential and biocompatibility, but its application in bone tissue engineering is limited by mechanical property and degradation.
OBJECTIVE：To construct col agen/bioactive glass/chitosan composite scaffolds with good mechanical property, anti-degradation ability and bone repair property.
METHODS：Bioactive glass/col agen composite scaffolds with chitosan as dispersant were prepared by lyophylization. Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, and dynamic biomechanical testing were used to characterize the structure and properties of the composite scaffolds.
RESULTS AND CONCLUSION：Results show that charge-attractions in pre-prepared bioactive glass/chitosan solution increased the homogeneity of bioactive glass dispersed in col agen gel and the compressive modulus and strength increased significantly due to the homogeneity and intermolecular interactions between chitosan and col agen. The enzymatic degradation rate and mineralization activity in the simulated body fluid were also lower because of a high degree of embedment of bioactive glass in col agen/chitosan matrix, and entanglement of col agen in chitosan at molecular level, which decreased the exposure of bioactive glass to the simulated body fluid, and col agen to enzyme solution.