Improvement of corrosion resistance and biocompatibility of biodegradable metallic vascular stent via plasma allylamine polymerized coating

Plasma surface modification is one of the most effective ways not only to control the biodegradable behavior but also improve the biocompatibility of the biodegradable stents. In this work, we employed a one-step solvent-free process to construct a multifunctional plasma polymeric allylamine (PPAam) coating on biodegradable stent substrates (MgZnMn alloys and pure Fe). The PPAam surface is well characterized by XPS, GATR-FTIR, and AFM, displaying that the ultra-thin, pinhole-free polymer-likeamine-rich layers with a thickness of (similar to 250 nm) covered the substrates completely and uniformly. The results of electrochemical experiments as well as the analysis of corrosion products and surface morphologies confirmed the improved corrosion resistant properties of PPAam coated MgZnMn and Fe compared with their bare substrates. Endothelial cytocompatibility evaluation revealed that the PPAam coated MgZnMn and Fe presented good endothelial cells adhesion, spreading and proliferation properties. Also this protective coating could keep smooth with neither cracks nor webbings before or after the balloon expansion tests. The present study suggests that plasma polymerized allylamine technique might provide a promising potential platform in surface modification on biodegradable stents. (C) 2016 Elsevier Ltd. All rights reserved.