甲醇-水混合溶剂后处理制备丝素蛋白膜及其药物释放研究

Controlled Drug Release from Silk Fibroin Films Treated with Methanol-water Mixtures

采用溶液浇注法制备丝素蛋白薄膜,应用傅里叶红外光谱(FTIR)和X射线衍射(XRD)研究了浓度不同的甲醇-水混合溶剂处理后丝素蛋白薄膜的结构变化,并以罗丹明B为模型药物与丝素蛋白构建药物缓释体系,考察了丝素蛋白膜的结晶结构对药物释放动力学的影响.结果显示,在甲醇体积比浓度MeOH=50%～90%的范围内,丝素蛋白材料中以β-折叠为主的silk II结晶含量随着混合溶剂中甲醇浓度的增加而先增加后下降,在MeOH=80%附近出现最大值.罗丹明B从丝素蛋白膜的释放属于Fickian扩散机理,其扩散指数n随着丝素蛋白膜中β-折叠含量的增加而增加,silk II结晶是丝素蛋白材料药物释放的天然调节器.

Silk fibroin （SF） films were prepared using a casting method and the structural change owing to treatment with methanolwater mixtures of different concentrations was investigated by Fourier transform infrared spectroscopy （FTIR） and Xray diffraction （XRD）. The results were used to reveal the influence of structure on the release dynamics of Rhodamine B, a model compound loaded in the SF matrix. In methanol concentration ranging from 50% to 90%, the content of silk Ⅱ crystalline structure, constituted by flsheet, first increased and then decreased with increasing methanol concentration in the mixtures, reaching a maxi mum around 80%. It was found that Rhodamine B released from the SF film via Fickian mechanism, of which the diffusional exponent increased with increasing flsheet content in the matrix, suggesting that the silk II crystal could be used as natural regulator for drug release from SF material.