A bubble-propelled microneedle patch with photothermal-controlled NO release for eradicating biofilms in diabetic wounds

The progression of diabetic wounds to chronic non-healing ulcers is frequently driven by resilient bacterial biofilms that shield pathogens from eradication. Nitric oxide (NO) holds considerable promise for treating biofilm-associated infections due to its excellent biocompatibility and low propensity to induce drug resistance. However, its therapeutic potential is severely constrained by poor penetration through the dense biofilm matrix. Herein, we report a CO 2 bubble-powered microneedle patch designed to overcome this barrier and enhance the treatment of biofilm-infected diabetic wounds. The system incorporates oxidized mesoporous carbon nanoparticles (OMCN) that are loaded with the NO donor sodium nitroprusside (SNP) and subsequently coated with a phase-change material (PCM), yielding OMCN-SNP@PCM (OSP) nanoparticles. These nanoparticles are co-embedded with NaHCO 3 within a soluble hyaluronic acid microneedle array. Upon application to the acidic biofilm microenvironment, NaHCO 3 decomposes to generate CO 2 bubbles that actively propel OSP nanoparticles deep into the biofilm. Subsequent near-infrared laser irradiation triggers photothermal melting of the PCM coating, enabling controlled NO generation to disrupt and eradicate the biofilm. In vivo studies further demonstrate that this bubble-propelled patch not only exerts potent antibiofilm activity but also promotes collagen deposition and angiogenesis in diabetic wounds. Overall, this work presents a synergistic and microenvironment-responsive strategy for treating biofilm-infected diabetic wounds, thereby offering a promising platform for future clinical translation.