Surface Modification of Silk Fibroin Films with Zwitterionic Phosphobetaine to Improve the Hemocompatibility

Zwitterionic phosphobetaine bearing a hydroxyl and a zwitterionic group, 8-hydroxy-2-octyl phosphorylcholine (HOPC), was synthesized and constructed to the surface of silk fibroin(SF) films in order to improve the hemocompatibility of fibroin films by a an isocyanate head group. The surface characteristics of the modified films were measured by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and electron spectroscopy for chemical analysis (ESCA), displaying the successful immobilization of Zwitterionic phosphobetaine on the surface of these fibroin films. Moreover, the further platelet adhesion test in platelets rich plasma (PRP) of human beings showed the zwitterionic phosphobetaine led mainly to good nonthrombogenicity. The experimental results indicated a reasonable approach to improve the blood compatibility of fibroin films.