Sulfobetaine zwitterionic/quaternary ammonium cationic copolymers as high-efficiency antifouling and bactericidal coatings for polyurethane substrates

Bacterial infection is a key challenge for implant and blood-contacting biomaterials due to the biofouling and thrombus formation at their interface. Therefore, design and fabrication of high-efficiency antifouling and bactericidal coatings on substrates are extremely important for biomedical devices. In this paper, we successfully developed a coating with high-efficiency antifouling and bactericidal properties on a polyurethane (PU) substrate through polydopamine (PDA), polyethyleneimine (PEI) assisted codeposition and amidation reaction using our synthesized copolymers of mono-2-(methylpropoxy) ethyl succinate (MSA), sulfobetaine methacrylate (SBMA) and/or ethyl methacrylate trimethyl ammonium chloride (MAC). All the coatings showed improved hydrophilicity. And due to the unique surface hydration of sulfobetaine (SB) zwitterionic groups and high ability to kill attached bacteria of quaternary ammonium cationic groups, the coatings constructed by tripolymers of MSA/MAC/SBMA (defined as PCAS) showed greatly reduced protein adsorption (BSA and Fg), platelet and cell adhesion, and excellent antifouling activity. This bioinspired and efficient surface modification strategy with dual-function coatings has potential application prospects in implantable biomedical devices.