A near-infrared light absorbable hydrogel with antibacterial effect for mild photothermal regeneration of infected wounds

Abstract

Bacterial wounds are currently a growing concern in clinical practice, with the rising challenge posed by antibiotic resistance and inflammation. Traditional photothermal therapy (PTT) presents great efficiency in treating infected wounds; however, it has the limitation of thermal damage to healthy tissues. To overcome this challenge, the strategy of mild-PTT is proposed using hyaluronic acid-coated bismuth sulfide (Bi₂S₃) nanoparticles (BiH NPs) alongside allantoin within gelatin/sodium alginate-based hydrogel formulation to eliminate bacterial infections and facilitate the wound healing procedure. BiH NP as a photothermal agent is synthesized via a facile and environmentally friendly method with excellent biocompatibility and high photothermal efficiency. Our formulation demonstrated good mechanical resistance with high recoverable compressibility and favorable bactericidal effects on Escherichia coli and Staphylococcus aureus bacteria. Moreover, as a multifunctional system, it accelerates wound healing in non-infected and infected full-thickness wound models with desirable in vitro and in vivo biocompatibility. With the simple preparation procedure, potent antibacterial effect, and high photothermal efficiency, this hydrogel emerges as a promising candidate for the treatment of infected wounds.