Airborne ¹O₂ Delivery via a Superhydrophobic Dressing as a Pathway to Next-Generation Wound Therapies, an In Vivo...

Antimicrobial photodynamic therapy (aPDT) has been investigated as a promising therapy for treating wound infections. However, its clinical application is limited by tissue hypoxia, poor photosensitizer (PS) penetration, and off-target toxicity. In this work, we use a light-activated, contactless aPDT system that delivers airborne singlet oxygen (¹O₂) via a compliant, transparent superhydrophobic (SH) bandage. The verteporfin-coated SH membrane generates ¹O₂ while minimizing direct contact between PS and wound tissue. In a murine third-degree burn model infected with methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa, a single SH-aPDT treatment significantly reduces bacterial burden and accelerates wound closure. It enhances collagen deposition, stimulates angiogenesis, increases α-SMA⁺ myofibroblast activity, and decreases COX-2 expression, indicating attenuated inflammatory signaling. Administration of two treatments 24 h apart further augments bacterial clearance and improves healing outcomes. SH-aPDT also promotes a pro-regenerative immune response, as evidenced by increased M2 macrophages. These findings demonstrate that airborne ¹O₂ delivery through SH bandages is a promising approach for the management of infected, hypoxic, or antibiotic-resistant wounds, with great potential for clinical translation in wound care.