Clickable Zwitterionic Copolymer as a Universal Biofilm‐Resistant Coating

Abstract Hospital‐acquired infections are often caused by bacterial biofilms on medical devices. To prevent biofilm formation, herein, a universal coating of an antifouling polymer that inhibits the initial adhesion of bacteria is developed. This copolymer is made of methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate‐substituted dihydrolipoic acid (DHLA) (poly(MPC‐DHLA)). The MPC units provide the antifouling property, while the DHLA units offer cross‐linkable sites via thiol‐ene reactions to form the stable coated copolymer film. Without the requirement for covalent surface grafting, the poly(MPC‐DHLA) coating on various biomedically relevant substrates is investigated, where X‐ray photoelectron spectroscopy, water contact angle measurements, atomic force microscopy, and ellipsometry are used to confirm the success of the surface coating. Moreover, to mimic an actual clinical use, the copolymer coating is applied on a titanium dental substrate and the ability to inhibit biofilm formation by Staphylococcus aureus is quantified and visualized by crystal violet staining and scanning electron microscopy, respectively. As compared with the bare substrate, an effective reduction in bacterial adhesion and suppression of the subsequent biofilm formation is observed on the copolymer‐modified substrate. These features are maintained for up to 7 d indicating the durability as well as universal applicability of this coating approach.