Evaluation of Living Bacterial Therapy Assisted by Ph/reactive Oxygen Species Dual-Responsive Sodium Alginate-Based Hydrogel for Wound Infections

The enhancement of antimicrobial wound dressings is of utmost importance in light of the escalating risk of antibiotic resistance caused by excessive antibiotic usage. Conventional antimicrobial materials eradicate pathogenic bacteria while impeding the proliferation of beneficial bacteria during the management of wound infections, thereby disturbing the equilibrium of the skin micro-ecosystem and engendering recurrent cutaneous complications. Lactobacillus rhamnosus (L.rha) is a probiotic that can inhibit the growth of certain pathogenic bacteria by secreting a large number of metabolites. In this paper, we synthesized a cross-linker (SPBA) with a boric acid molecule from succinic acid and 4-(bromomethyl)phenylboronic acid, which formed a boric acid ester bond with a diol on the natural polysaccharide sodium alginate (SA), and obtained a pH/reactive oxygen species (ROS) dual-responsive hydrogel (SA-SPBA) for loading L.rha to treat wound infections. The SA-SPBA@L.rha hydrogel improves the survival of L.rha during storage and has good injectability as well as self-healing properties. The hydrogel showed good biocompatibility, the antimicrobial effect increases in a dose-dependent manner, and it has a certain antioxidant and anti-inflammatory capacity, accelerating wound repair. The use of SA-SPBA@L.rha hydrogel provides a safe and effective strategy for the repair of skin wound infections.