Polyurethane Surface with Antibacterial and Antifouling Properties Enabled via Surface Grafting of Imidazolium Salt Chitosan Graft-Polyzwitterionic Copolymer

Protein adsorption and bacterial colonization on implantable medical devices often cause postoperative infections coupled with complications, even leading to function failure of implantable devices. To reduce these risks, it is essential and feasible for these devices to improve their antibacterial and antifouling capabilities by surface modification. In this work, an antibacterial and hydrophilic polymer, IMCTS–PMPC-PAA, was developed by a one-step in situ graft polymerization of imidazolium salt chitosan (IMCTS), 2-methacryloyloxyethyl phosphorylcholine (MPC), and acrylic acid (AA). Then, it was grafted onto the polydopamine/polyethylenimine (PDA/PEI)-modified polyurethane (PU) surface to form a PDA/PEI-IMCTS-PMPC coating. The antibacterial and antifouling performance of the PDA/PEI-IMCTS-PMPC coating was tested by the plate counting method and the antiprotein adsorption assay. The results showed that the coating had excellent antibacterial activity compared with bare PU, with antibacterial rates of 99.94 ± 0.06 and 99.82 ± 0.09% against Escherichia coli and Staphylococcus aureus, respectively. Meanwhile, the antiprotein adsorption performance of the coating was also excellent, with antiprotein adsorption rates of 85.78 ± 2.14 and 89.30 ± 2.12% for lysozyme (LYS) and bovine serum albumin (BSA), respectively. In addition, the coating stability test, platelet adhesion and hemolysis tests, and cytotoxicity assay demonstrated the good stability and biocompatibility of the PDA/PEI-IMCTS-PMPC coating. Overall, this study offers a viable approach to the development of coatings for implantable medical devices.