矿化丝素/聚乳酸载万古霉素复合材料的制备与改性研究

Study on preparation and modification of mineralized silk fibroin/polylactic acid vancomycin composite

矿化胶原/聚乳酸复合材料用于修复松质骨缺损取得了进展,但同时力学性能、药物控释等方面有待进一步提高。研究通过生物矿化的原理制备了粒径范围在5~20μm的矿化丝素并与聚乳酸、万古霉素复合,通过控制降温速率实现对聚乳酸分子结晶过程的改变,从而调节复合材料的性能,制备出结晶态SF/HA/PLA1和非结晶态SF/HA/PLA2的两种矿化丝素/聚乳酸复合材料,并研究其对微观形貌、药物释放、力学性能及降解率的影响。结果表明不同的结晶时间会使材料的微观孔径在10~90μm之间变化;SF/HA/PLA2材料10 d的药物释放率为64.3%,小于SF/HA/PLA1材料的73.4%;SF/HA/PLA2材料显韧性,在形变大于5%时不被破坏,表现出更好的力学性能,SF/HA/PLA1显脆性,到达1MPa之后断裂;SF/HA/PLA1在30 d后的降解率在5.5%左右,SF/HA/PLA2的降解率在7.8%左右。通过对矿化丝素/聚乳酸载万古霉素材料制备条件的控制有望更好的适合用于感染性骨缺损的修复拓宽其在骨科临床上的应用。

The use of mineralized collagen/polylactic acid composite materials for repairing cancellous bone defects has made progress,but at the same time,the mechanical properties and controlled release of drugs need to be further improved.In this study,mineralized silk fibroin with a particle size in the range of 5-20μm is prepared by the principle of biomineralization and compounded with polylactic acid and vancomycin.By controlling the cooling rate,the crystallization process of polylactic acid molecules is changed,thereby adjusting the properties of the composite material.Two kinds of crystalline SF/HA/PLA1 and non-crystalline SF/HA/PLA2 mineralized silk fibroin/polylactic acid composites are prepared and its effect on micro-morphology,drug release,mechanical properties and degradation rate is studied.The results show that different crystallization time will change the micropore size of the material between 10-90μm.The drug release rate of SF/HA/PLA2 material in 10 days is 64.3%,which is less than 73.4%of SF/HA/PLA1 material.SF/HA/PLA2 material is tough,and it will not be destroyed when the deformation is greater than 5%,showing better mechanical properties.SF/HA/PLA1 is brittle and breaks after reaching 1MPa.The degradation rate of SF/HA/PLA1 after 30 days is about 5.5%,and the degradation rate of SF/HA/PLA2 is about 7.8%.In this paper,the control of the preparation conditions of mineralized silk fibroin/polylactic acid-loaded vancomycin material is expected to be better suitable for the reparation of infectious bone defects and broaden its clinical application in orthopedics.