Injectable, Self-Healing, Ultrasonic-Triggered Piezocatalytic Hydrogels for Enhanced Antibacterial Efficacy and Wound Healing: An In Vitro Study

Wound healing remains a persistent challenge in clinical medicine due to the high susceptibility of skin injuries to bacterial infections. The development of nanocomposite hydrogels with potent antibacterial properties is therefore critical to enhancing wound closure and tissue regeneration. Herein, we report a self-healing hydrogel platform that integrates ultrasonic-triggered piezocatalytic therapy for the effective treatment of bacteria-infected wounds. The hydrogel was engineered by incorporating calcium titanate (CaTiO3, CT) nanoparticles into a chitosan/vanillin matrix, with dynamic Schiff base linkages conferring autonomous self-healing behavior. Upon ultrasonic stimulation, the embedded CT nanoparticles generate reactive oxygen species (ROS) via a strong built-in electric field, achieving high antibacterial efficacy localized to the wound site and thereby improving therapeutic biosafety. The self-healing nature of the hydrogel ensures continuous protection and facilitates rapid tissue repair. Notably, the system demonstrates a synergistic antibacterial mechanism through the combined effects of mechanical disruption and catalytic ROS generation. This study underscores the potential of piezocatalytic self-healing hydrogels as advanced wound dressings and provides a promising platform for the development of intelligent, stimuli-responsive biomaterials for precision regenerative therapies.