抗菌丝素蛋白水凝胶敷料的制备

Preparation of Antimicrobial Silk Hydrogels for Surgical Dressings

摘要: 季铵盐类抗菌剂作为凝胶促进剂，诱导丝素蛋白水溶液快速原位凝胶化从而制备抗菌性丝素水凝胶敷料。利用X射线衍射、红外光谱、扫描电镜、zeta电位分析、差热分析等手段对所制丝素水凝胶的结构、zeta电位、热稳定、降解性及其抗菌性能进行了表征。研究结果表明，季铵盐会引起丝素颗粒负电位值下降，由此促发形成的丝素水凝胶为β-折叠片层结构，凝胶内部形貌为多孔的三维网状结构，且对革兰氏阳性菌和阴性菌都有很明显的抗菌效果。同时由体外降解、差热分析结果可知，季铵盐引发丝素蛋白溶液快速形成水凝胶，蛋白酶可以在体外降解水凝胶。季铵盐在水凝胶中主要以无定形或亚稳态晶体状态存在，容易扩散释放，达到较好的抗菌效果。抗菌性原位丝素蛋白水凝胶预计可以用于外科伤口敷料。

Abstract: Using quaternary ammonium salts (QAS) as initiating agents, silk fibroin aqueous solutions were induced to gel rapidly. The structure, zeta-potential change and thermal stability properties of QAS-induced silk gel were charac- terized by means of X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), zeta- potential measurements and differential thermal analysis (DTA). The results show that QAS-induced silk gelation is accompanied by the formation of β-sheets and less negative zeta-potential values. With the observation of SEM, the internal morphology of gel exhibited a porous three-dimensional network structure. In vitro degradation and DTA analysis revealed that QAS-induced fibroin gel was not quite stable and disintegrated more easily in the enzyme solu- tion. Also, QAS is amorphous or metastable crystal state in silk gel and thus easy to release and diffuse. The antibacte- rial test in vitro suggested that silk-QAS gel showed distinctly antibacterial activities against both Gram-positive and Gram-negative bacteria. In situ antimicrobial silk hydrogel is expected to be used for a surgical dressing.