A Gold Nanocluster Constructed Mixed-Metal Metal–Organic Network Film for Combating Implant-Associated Infections
Guangyu Chu, Chunlei Zhang, Yifei Liu, Zanxia Cao, Lirui Wang, Yunfeng Chen, Wenjie Zhou, Guo Gao, Kan Wang, Daxiang Cui
Abstract
The development of modular strategies for programming self-assembled supramolecular architectures with distinct structural and functional features is of immense scientific interest. We reported on the intrinsic antibacterial capability of anionic amphiphilic gold nanoclusters (GNCs) capped by para-mercaptobenzoic acid, which was closely related to the protonation level of terminal carboxylate groups. By using of the metal–ligand coordination-driven and solvent evaporation-induced self-assembly, we constructed GNCs-based mixed-metal metal–organic network (MM-MON) films on titanium disks as antibacterial nanocoatings. Taking the reasonable utilization of tetravalent metal ions M4+ (Ti, Zr, Hf; hard Lewis acid) and bactericidal divalent metal ions M2+ (Cu, Zn; borderline acid) co-incorporated metal–carboxylate coordination bonds, the MM-MON films exhibited superior stability due to the robust M4+–O bonds and M2+ releasing behavior resulting from the labile M2+–O coordinating. Together, the MM-MON films integrated the bacteria-responsive character of GNCs, exceptional chemical stability, and greatly enhanced antibacterial activity, ultimately killing adherent bacteria and initiating a self-defensive function. In a rat model for subcutaneous implant-associated infection, the MM-MON nanocoating showed an approximately 2 and 1 log lower multidrug-resistant Staphylococcus aureus implant and tissue colonization, respectively. The generalizable modular strategy of the GNC–metal networks is amenable to facilitate the functionalization of metal surfaces for combating implant-associated infections.