生物活性玻璃与壳聚糖复合的骨修复材料

Combination of bioactive glass and chitosan as a bone repair material

背景:生物活性玻璃是一种多相复合材料,具有良好的生物活性、骨传导性及生物相容性,但作为骨修复材料仍然存在不能完全降解、机械强度较低等不足。目的:设计生物活性玻璃/壳聚糖复合材料骨组织工程支架,并检测其理化性能。方法:将2.0%壳聚糖盐酸溶液与β-甘油磷酸钠以7∶1的体积比混合制备壳聚糖溶液。称取0.5,1.0,1.5 g生物活性玻璃分别加入上述壳聚糖溶液中,使得壳聚糖与生物活性玻璃的质量比为2∶1,1∶1及1∶1.5。将复合材料浸泡于模拟生理体液中7 d进行体外矿化。结果与结论:扫描电镜见复合支架具有相互贯通的多孔结构,孔隙率最高可达89%,孔径大小合适,为100-300μm,生物活性玻璃以针状形式分散在壳聚糖支架之间,均匀排列,被壳聚糖支架充分包裹结合紧密。随生物活性玻璃含量的增加,复合材料的孔隙率逐渐下降,断裂强度逐渐升高,他们之间呈正相关性。X射线衍射图及傅里叶变换红外光谱证实复合支架中的单一材料未发生性质改变,示差扫描量热法分析显示正常体温情况下材料无质量丢失。矿化3 d后材料表面形成的羟基磷灰石逐渐长大为绒毛状,数量也明显增多;矿化7 d后绒毛状的羟基磷灰石长成为针状,数量进一步增多,且众多的矿化物结成球状。

BACKGROUND： Bioactive glass, a multi-phase composite material, has good biological activity, bone conductivity and biocompatibility, but as a bone repair material it cannot be completely degraded, and has low mechanical strength that is insufficient. OBJECTIVE： To design a kind of bioactive glasses/chitosan composite scaffold, and to investigate its physicochemical properties and cell compatibility. METHODS： Hydrochloric acid solution containing 2.0% chitosan was mixed with ^-glycerophosphate at a radio of 7：1 to prepare chitosan solution. Bioactive glasses of 0.5, 1.0, 1.5 g were added into the prepared chitosan solution, and the mass ratios of chitosan and bioactive glass were 2：1, 1：1, and 1：1.5 respectively. The composite materials were immersed and mineralized in simulated body fluid for 7 days. RESULTS AND CONCLUSION： Scanning electron microscopy showed that the composite scaffold had an interconnected porous structure with the porosity of 89% and the pore size of 100-300 pm; bioactive glasses dispersed in a needle shape between the chitosan scaffolds, arranged evenly, and were fully wrapped tightly bythe scaffolds. With the increase in mass of bioactive glass, the porosity of the composites decreased, but the fracture strength gradually increased. There was a positive correlation between the composite porosity and fracture strength. X-ray diffraction and Fourier transform infrared spectroscopy confirmed that the composite scaffold appeared to have no changes in the nature of single materials, and differential scanning calorimetry analysis showed no mass loss at normal body temperature. After 3 days of mineralization, hydroxyapatite forming on the material surface gradually grew up as a villous shape, and also significantly increased in number. After 7 days of mineralization, hydroxyapatite changed from a villous shape to a needle shape, the amount of hydroxyapatite was increased further, and many mineralized products were in a spherical shape.