Hydrophilic cationic surface modification confers simultaneous antibacterial and antithrombotic properties to blood-contacting devices.

Abstract

The clinical application of blood-contacting medical devices carries lethal risks such as sepsis and vascular embolism, with thrombosis and bacterial infection being core complications that severely threaten device safety. Although cationic surface modification strategies exhibit broad-spectrum antibacterial properties without the risk of bacterial resistance, non-specific adhesion induced by electrostatic effects both diminishes antibacterial efficacy and exacerbates thrombotic risk. Hydrophilic modification techniques are extensively employed in anti-adhesion surface coating research. This study introduces hydrophilic modifications onto cationically modified catheter surfaces, effectively reducing non-specific adhesion to achieve sustained dual antibacterial and anti-thrombotic efficacy. Through redox-initiated radical polymerisation, polyhexamethylene guanidine (PHMG) and the zwitterionic compound 2-methacryloyloxyethyl phosphorylcholine (MPC) were covalently grafted onto the polyurethane (PU) catheter surface. Following in vitro and in vivo antibacterial and blood cell adhesion assays to determine the optimal PHMG-MPC ratio exhibiting concurrent hydrophilicity, potent antibacterial activity, and anti-thrombotic properties, intravascular implantation studies validated its efficacy. In summary, the strategy of surface-modifying PU with PHMG/MPC (PU-PM) resolves issues associated with cationic surface modifications arising from non-specific adhesion. This renders it more suitable for clinical requirements in blood-contacting devices, significantly enhancing its potential for clinical translation. STATEMENT OF SIGNIFICANCE: 1. Through redox-initiated polymerisation, methylacrylamidated polyhexamethylene guanidine (PHMG-MA) and 2-methacryloyloxyethyl phosphatidylcholine (MPC) were covalently bonded to the polyurethane surface, achieving hydrophilic modification of the cationic surface. 2. This synergistic modification strategy achieves functional integration of antibacterial and antithrombotic properties, overcoming the performance limitations imposed by the non-specific adhesion associated with single cationic modification techniques.