A ROS-responsive cryptotanshinone-loaded hydrogel microneedle patch for infected wound healing

Infected wound healing remains challenging because bacterial colonization, excessive reactive oxygen species (ROS), and persistent inflammation jointly disrupt the normal repair process. In this study, we developed a ROS-responsive hydrogel microneedle patch for local delivery of cryptotanshinone (CPT) to promote infected wound healing. The fabricated microneedles exhibited uniform morphology, adequate mechanical strength, and oxidation-responsive swelling, degradation, and drug-release behavior. In vitro, the CPT-loaded microneedles inhibited bacterial growth, reduced intracellular ROS accumulation, attenuated inflammatory responses, and improved fibroblast viability and migration under oxidative stress conditions. In a mouse model of infected wounds, the CPT-loaded microneedle patch accelerated wound closure, reduced bacterial burden, improved histological repair, and promoted collagen remodeling. These therapeutic effects were accompanied by reduced TNF-α and IL-6 levels, increased IL-10 expression, and suppression of NF-κB activation in wound tissue. Collectively, this ROS-responsive CPT-loaded microneedle patch provides a promising localized therapeutic strategy for infected wound healing through combined antibacterial, antioxidant, and anti-inflammatory effects.