钙离子含量对再生丝素蛋白纤维生物降解性的影响

Impact of Calcium Ion Content on Biodegradability of the Regenerated Silk Fibroin Fiber

丝素蛋白纤维是一种可降解的生物材料。在再生丝素蛋白纤维制备过程中添加不同浓度的氯化钙,通过红外光谱和核磁共振光谱测定、蛋白酶降解处理、机械性能测试等,解析钙离子含量对再生丝素蛋白纤维的蛋白质结构、力学性能及生物降解性能的影响。当添加的氯化钙质量分数为11%时,再生丝素蛋白纤维中的钙离子浓度接近天然丝素蛋白中谷氨酸和天冬氨酸的浓度,丝素蛋白纤维的机械强度下降90%,丝蛋白降解速率明显加快。研究结果提示,含适量钙离子的再生丝素蛋白纤维可以提高其在生物体内的降解速率,有利于在医用生物材料领域的广泛应用。

The native silk fibroin fiber from Bombyx moil is a kind of degradable biomaterial. In this study, different concentrations of calcium chloride were added during preparation of regenerated silk fibroin fiber. Through infrared and nuclear magnetic resonance spectrometric measurements, protease degradation treatment and mechanic property test, the effect of calcium ion on protein structure, mechanic property and biodegradation property of the regenerated fibroin fiber were explored. When mass fraction of the added CaCI2 was 11%, calcium ion concentration in the regenerated fibroin fiber was close to that of glutamic acid and aspartic acid in the native silk fibroin. Mechanic strength of the regenerated fibroin fiber decreased by 90% and degradation of the regenerated fibroin fiber was expedited obviously. These results suggest that the regenerated fibroin fiber containing suitable amount of calcium ion could increase its biodegradation speed inside organisms, being favorable for extensive application in medicinal biomaterials.