Inflammatory Microenvironment-Responsive Hydrogels Enclosed with Quorum Sensing Inhibitor for Treating Post-Traumatic Osteomyelitis.

Non-antibiotic strategies are desperately needed to treat post-traumatic osteomyelitis (PTO) due to the emergence of superbugs, complex inflammatory microenvironments, and greatly enriched biofilms. Previously, growing evidence indicated that quorum sensing (QS), a chemical communication signal among bacterial cells, can accelerate resistance under evolutionary pressure. This study aims to develop a medical dressing to treat PTO by inhibiting QS and regulating the inflammatory microenvironment, which includes severe oxidative stress and acid abscesses, through a reactive oxygen species (ROS)-responsive bond between N1- (4-borobenzoyl)-N3-(4-borobenzoyl)-the N1, the N1, N3, N3-tetramethylpropane-1,3-diamine (TSPBA) and polyvinyl alcohol (PVA), and the amino side chain of hyperbranched polylysine (HBPL). Physically enclosed QS inhibitors subsequently exerted the antibacterial effects. This hydrogel can scavenge hydrogen peroxide (H2O2), superoxide anion free radical (·O2 -), hydroxyl radicals (·OH) and 2,2-di(4-tert-octylphenyl)-1-picryl-hydrazyl (DPPH) to reduce oxidative stress and inhibit "bacteria-to-bacteria communication", thus clearing planktonic bacteria and biofilms, accelerating bacterial plasmolysis, reducing bacterial virulence and interfering with membrane transport. After in vivo treatment with hydrogel, nearly all bacteria are eliminated, inflammation is effectively inhibited, and osteogenesis and bone repair are promoted to facilitate recovery from PTO. The work demonstrates the clinical translational potential of the hydrogel in the treatment of drug-resistant bacteria induced PTO.