Near-infrared-driven self-propelled Janus nanomotors penetrate persistent biofilms to deliver anti-inflammatory and photothermal therapies for accelerated wound healing.

Abstract

Biofilms, formed within the necrotic tissue of chronic infected wounds, create a shielded microenvironment that promotes bacterial persistence and disrupts the healing process. This initiates a self-perpetuating cycle of bacterial infection and dysregulated host inflammation, making wound healing profoundly challenging. Here, we designed and fabricated a near-infrared (NIR)-driven Janus nanomotor capable of penetrating biofilms via autonomous propulsion to simultaneously deliver anti-inflammatory and photothermal therapy (PTT) for effective wound healing. Using a spatially selective super assembly strategy, we fabricated the self-thermophoresis Janus nanomotors with Au nanostars (AuNS) as the fundamental photothermal agent, enabling propulsion under NIR light irradiation. Combined with the spiky surface on the AuNS, the nanomotor can efficiently penetrate bacterial membranes. Furthermore, the Au was functionalized with humic acids (HAs) to introduce immunomodulatory functionality. We demonstrated that the Janus HAs-AuNS-PAA/mSiO₂ nanomotor exhibits excellent biofilm penetration ability and efficacy in eliminating bacteria through a combination of anti-inflammatory and photothermal effects. In vitro and in vivo experiments confirmed that these nanomotors possess nanomolar-level bactericidal and anti-inflammatory efficacy, and they significantly accelerated wound healing in a mouse model. This platform combines potent, antibiotic-free antibacterial action with targeted immunomodulation, offering a comprehensive solution for managing persistent infectious wounds.