The anticoagulant ability of ferulic acid and its applications for improving the blood compatibility of silk fibroin

Abstract

The hemocompatibility of silk fibroin (SF) was improved with ferulic acid (FA) by graft polymerization. Ferulic acid is an active ingredient of many Chinese herbal medicines, such as Chuanxiong (Rhizoma ligustici wallichii), Danggui (Angelica sinensis) and Awei (Asafoetida giantfennel), which have been used to treat cardiovascular diseases by Chinese physicians for thousands of years. The inhibitory functions of FA on blood coagulation and erythrocyte agglutination were first characterized by a Lee–White test tube method and a micropipette technique, respectively. Then, FA was immobilized on SF by graft polymerization and the surface composition of modified SF was characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR), x-ray photoelectron spectroscopy (XPS) and optical microscopy. The anticoagulant activity of modified SF was assessed, respectively, by in vitro clotting time measurements on a photo-optical clot detection instrument and with the Lee–White test tube method. The test results indicated that in comparison to untreated SF, the anticoagulant activity of modified SF has been improved significantly. Moreover, the SF surface composition is altered by FA but its β-sheet conformation is not disturbed.