Improved immobilization of biomolecules to quinone-rich polydopamine for efficient surface functionalization

Polydopamine (PDA), a bio-inspired polymer, has been very attractive for diverse functional applications by immobilizing biomolecules. In this work, a novel approach of using PDA for improved biomolecule immobilization was developed. A thin PDA layer was strategically coated onto 316L stainless steel and thermally treated at 150°C (PDA-Th150). Subsequently, amino-terminated polyethylene glycol (mPEG-NH2) or vascular endothelial growth factor (VEGF) was immobilized onto PDA and PDA-Th150 surface. The results of attenuated total reflection-Fourier transform-infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) showed higher coverage of quinine on PDA-Th150 surface. The functionalized PDA-Th150 significantly improved its ability of immobilizing mPEG-NH2 or VEGF, as shown by platelet adhesion test and endothelial cell proliferation experiments. This novel approach may also be used for efficient immobilization of biomolecules on different metal devices.