Photothermal-responsive Au nanorod-silica nanocomposite with on-demand curcumin release for sequential therapy of biofilm infections

Bacterial biofilms in infected wounds and implant-associated infections are highly tolerant to antibiotics and often coexist with excessive inflammatory reactive oxygen species (ROS), resulting in treatment failure and delayed healing. Here, we report a photothermal-responsive curcumin-loaded gold nanorod-silica hybrid nanocomposite (Cur@T-Au) for antibiotic-free infection control and infectious microenvironment remodeling. Gold nanorods were electrostatically assembled onto hollow mesoporous silica nanoparticles (H Au) and further coated with polyethyleneimine to yield a positively charged carrier (T-Au) with bacterial-adhesive capability. Upon near-infrared irradiation, Cur@T-Au demonstrated rapid photothermal hyperthermia synergized with photothermal-responsive triggered structural degradation for controlled release of curcumin, exhibiting broad-spectrum antibacterial activity and potent antibiofilm efficacy. Meanwhile, Cur@T-Au effectively scavenged free radicals and reduced intracellular ROS, and markedly modulated inflammatory responses. In vivo , Cur@T-Au significantly reduced bacterial burden and accelerated healing in infected wound and implant-related infection models, accompanied by improved tissue regeneration and inflammation resolution. Collectively, Cur@T-Au provides an on-demand photothermal-responsive sequential therapeutic strategy that integrates bactericidal action, ROS mitigation and degradability, offering a promising non-antibiotic platform for treating biofilm-associated infections.