Enhanced endothelialization guided by fibronectin functionalized plasma polymerized acrylic acid film

The plasma polymerized acrylic acid (PPAA) films with high carboxyl concentration were fabricated by low temperature plasma polymerization technology. Vacuum thermal treatment was used to modify the PPAA films. The stability of the PPAA film was evidenced by scanning electron microscopy (SEM). The result of toluidine blue-O (TBO) method showed that the -COOH concentration on the surface of the PPAA films decreased from 20.73 nM to17.90 nM after vacuum thermal treatment. Fibronectin (Fn) was successfully covalently immobilized onto the modified surface PPAA via a covalent bond reacted with carboxyl groups. Diffuse reflectance Fourier infrared transform spectroscopy (DRFTIR) and X-ray photoelectron spectroscopy (XPS) were utilized to characterize the layer-by-layer PPAA surface modification. From the evaluation of immunostaining for actin and Cell Counting Kit-8 (CCK-8), the surface of Fn-immobilized thermal treated PPAA films could be used to enhance the adhesion and proliferation of human umbilical vein endothelial cells (HUVECs). Especially, the exposure of RGD domain existing in the immobilized Fn was ascertained by ELISA, which was one of main improvement factors of HUVEC's adhesion and proliferation. This study demonstrated a promising surface modification used for vascular devices.