A chondroitin sulfate/chitosan composite coating for anticoagulation on cardiovascular implants

Developing durable anticoagulant coatings for cardiovascular implants remains a major research challenge. Heparin, the current gold-standard anticoagulant, faces challenges due to rapid elution from coated surfaces. This article reports a new heparin-alternative anticoagulant coating system engineered through rational design of a dual-functional chondroitin sulfate derivative (methacrylated/aldehyde-modified chondroitin sulfate, CSMAO) and sulfonated chitosan (SCS). The hierarchical architecture was constructed via sequential layer-by-layer (LbL) assembly on polydopamine (PDA)-functionalized 316 L stainless steel substrates. The material characterization methods included Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS). The grafting rate of glycidyl methacrylate was 20.05 %, with an aldehyde substitution degree of 48.61 %, and the sulfonation degree of SCS reached 46.96 %. The composite coating exhibited excellent biocompatibility and anticoagulant properties. Coagulation profiling indicated comparable extrinsic pathway regulation to that of heparin controls along with superior intrinsic pathway inhibition (P < 0.01). This rationally designed coating system shows translational promise for improving the hemocompatibility of cardiovascular implants.