Fabrication of ionic liquid-functionalized aliphatic polycarbonate brushes for self-polishing antibacterial application

To meet the development of multifunctional surfaces with long-term antibacterial activity for biomaterials and implantable devices, herein, a novel self-polishing antibacterial surface was developed. The functionalized surface was prepared by first surface-initiated ring-opening grafting polymerization (SI-ROP) of a cyclic carbonate monomer 4′-(fluorosulfonyl)benzyl-5-methyl-2-oxo-1,3-dioxane-5-carboxylate (FMC) containing a sulfonyl fluoride group in the side chain onto the material surface and then by a “sulfur(IV)-fluorine” exchange (SuFEx) postclick modification reaction to link the imidazolium salt ionic liquid to the polyFMC (PFMC) brush. In vitro experimental results showed that the functionalized surface has good biocompatibility, enzymatic biodegradable properties and excellent bactericidal properties, which can effectively kill E. coli (∼94%) and S. aureus (∼93%). In addition, the functionalized surface can release the killed bacteria (∼90%) several times efficiently under the action of lipase enzymatic degradation, restoring the original bactericidal function of the surface, thus forming a dynamic self-polishing and self-renewing antibacterial surface. Therefore, this method for the fabrication of self-polishing antibacterial surfaces may offer innovative insights into applications of biomedical implant materials.