Polyurethane Surface\nwith Antibacterial and Antifouling\nProperties Enabled via Surface Grafting of Imidazolium Salt Chitosan\nGraft-Polyzwitterionic Copolymer

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