Promoted Cytocompatibility of Silk Fibroin Fiber Vascular Graft through Chemical Grafting with Bioactive Molecules

Natural silk from Bombyx mori has been used as medical sutures for several decades,and regenerated silk fibroin( RSF)based biomaterials have been increasingly studied in the past thirty years. However,vascular graft derived from silk fibroin fiber has been explored in recent several years with development of textile science and engineering. Moreover,endothelialization of vascular graft has been seen as an ideal strategy for preventing thrombosis and getting higher patency in a long term. Therefore,in the present work silk fibroin fiber vascular graft( SF) was chemically grafted with bioactive molecules such as heparin and RSF to improve the cytocompatibility. 3-aminopropyl-triethoxysilane(APTES),1-ethyl-3-(3-dimethylaminopropyl) carbodiie hydrochlide( EDC · HCl),and N-hydroxysuccinimide( NHS) have been employed as coupling agent and crosslinking agents,respectively. Microscopy and ATRFTIR were used to characterize the surface changes and the structure of the grafts after treatment,respectively. Cell culture in vitro and MTT assay were conducted to determine the improvement of cell affinity to the graft. Furthermore,mechanical properties of the grafts before and after treatment were compared. The results showed that the chemical grafting was an effective method for improving the cytocompatibility of SF without significant loss of mechanical properties.