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.

Strategies toward development of antimicrobial biomaterials for dental healthcare applications

“…Free thiol groups generated from reduction were crosslinked by thiol-ene reaction in presence of alkenes to form a stable polymer film (Figure 7). In a later study by the same group, poly (MPC-DHLA) was coated on titanium dental substrate along with several biomedically relevant substrates and its potential to prevent biofilm formation was evaluated (Sae-ung et al, 2019). Ti substrate coated with zwitterionic copolymer inhibited biofilm formation by S. aureus as compared to uncoated substrates upto 7 days.…”

“…Schematic diagram depicting the process of poly(MPC‐DHLA) copolymer synthesis (figure reproduced with permission from Sae‐ung et al, 2019). ACVA, 4,4′‐azobis(4‐cyano‐valericacid); CPD, 4‐cyano‐4‐(thiobenzoylthio)pentanoicacid; DHLA, dihydrolipoic acid; HEMA, 2‐hydroxyethyl methacrylate; LA, lipoic acid; MPC, 2‐methacryloyloxyethyl phosphorylcholine; TFE‐2,2,2‐trifluoroethanol…”

Hydration behaviors of nonfouling zwitterionic materials

“…Biofouling is a common phenomenon that results from the attachment of biomolecules and microorganisms like proteins, cells, bacteria, mussels, algae, and seaweed to submerged surfaces, resulting in negative impacts on various applications. 1,2 For instance, in biomedical applications, the nonspe-cic attachment of proteins and cells to biomaterials aer implantation can trigger adverse immune responses, leading to an irrevocable foreign body reaction. 3 In the marine industry, biofouling can increase the hydrodynamic drag of vessels and cause pitting and crevice corrosion of metal surfaces.…”