Studies On The Silk Fibroin Blending Films For Corneal Repair

Silk protein has been wildly used in the field of biomedical materials, such as tissue repairing, scaffolds, drug delivery and wound dressing, due to its great and controllable degradability. In addition, silk protein can be fabric easily, it has been applied in the forms of fiber, sponges, films and microspheres. However, the silk fibroin blending films were either too brittle in dry state or easily dissolved in water to promise its application within a narrow area.In this study, in order to prepare composite films the hydrophilic pyrrolidone derivatives or carbamic acid ester compounds was blended with silk fibroin. The structure of silk fibroin composite membrane was detected by X-ray diffraction. The result showed that the silk fibroin films present crystalline structure because of the induction of the pyrrolidone derivatives or carbamic acid ester compounds. The type of the crystalline structure was changed when the amount of the additive different. However, the polyvirrypyrrolidone(PVP) has a poor compatibility with silk fibroin, therefore, it did not improve the properties of the silk fibroin films. The light transmittance of the blend films was measured on micro plate reader, the results showed that the composite films with high transmittance, especially for carbamic acid ester compounds/silk fibroin membrane, its light transmittance was above 95%. From the study of dissolve-loss rate, it can be found that the dissolve-loss rate of composite film induced by pyrrolidone derivatives or carbamic acid ester compounds was reduced significantly and insoluble in water.Mechanical tests showed that the flexibility was improved remarkablely and breaking strength can satisfied the require of the application.At last, the cytotoxicity of the composite films was tested by leaching solution method.The result showed that the monomer of N-vinyl-2-pyrrolidone/silk fibroin composite films have cell toxicity,others have slight cell toxicity and carbamic acid ester compounds/silk fibroin composite films have no cell toxicity, thererfore, it can be used for corneal repairing.Then, the rabbit stoma cells were extracted and cultured on the blend films to investigate the biocompatibility between corneal stoma and different composite films. It turned outthat all kinds of silk fibroin films were able to support corneal stoma cell adhesion and proliferation, which indicate that the pyrrolidone derivatives/silk fibroin films and carbamic acid ester compounds/silk fibroin films were expected to be a new type material for corneal tissue repair.