Photothermal Hydrogels, Microgels, and Nanogels: Recent Applications in Antibacterial Therapy

ABSTRACT Bacterial infection is one of the major challenges in wound healing. The emergence of multidrug‐resistant microorganisms has limited the effectiveness of conventional therapeutic agents, such as antibiotics, for wound treatment, highlighting the need for alternative antibacterial strategies. Among these emerging approaches, photothermal therapy (PTT) has attracted significant attention because of its ability to eradicate pathogenic microorganisms through localized heat generation upon near‐infrared (NIR) irradiation. Moreover, PTT can minimize systemic toxicity and potentially reduce the development of antimicrobial resistance, since in most applications it is localized and in general does not utilize conventional antibiotics. Organic, inorganic, and hybrid photothermal agents incorporated into gel‐based platforms can further enhance therapeutic efficacy by enabling localized drug penetration and retention, controlled and on‐demand cargo release upon NIR irradiation, and the creation of a favorable microenvironment for wound healing. This review summarizes recent advances in photothermal hydrogels, microgels, and nanogels for antibacterial applications. Overall, this review provides a comprehensive perspective on the design and fabrication of advanced photothermal antibacterial platforms and highlights their potential for the development of next‐generation therapeutic scaffolds for infected wound management.