Antimicrobial living double-layer skin dressing for inflammation reduction and skin barrier restoration to alleviate Malassezia -induced skin damage

Microecological imbalance associated with Malassezia overgrowth is closely related to the pathogenesis of diverse cutaneous disorders. However, conventional antifungal therapies face critical challenges, including pathogen resistance induction and inflammation exacerbation. To address these, developing safe and effective biological therapies is crucial for managing Malassezia -associated dermatitis. Here, a double-layer skin dressing is designed to efficiently inhibit Malassezia and mitigate Malassezia -induced skin inflammation in mice. The lower layer comprises Paenibacillus polymyxa JWYB12, which inhibits M. restricta , and the upper layer is a hydrogel composed of Pluronic F-127, polydopamine (PDA), anti-inflammatory exopolysaccharide EPS1, and oxygen-producing Spirulina (SP). Temperature elevation from 4°C to 37°C triggers rapid gelation and robust skin adhesion of the upper layer. SP-mediated oxygen production significantly upregulates energy metabolism genes, thereby enhancing JWYB12 proliferation, while EPS1 exerts a synergistic growthpromoting effect. Collectively, the upper layer markedly augments JWYB12 abundance and its inhibitory activity against M. restricta . In murine models, the dressing significantly reduces dermatitis scores and epidermal thickness, alleviates inflammation via cytokine downregulation, and restores skin barrier function by upregulating barrier proteins, thus effectively controlling M. restricta -induced inflammation. These properties make this double-layer skin dressing an effective clinical treatment for Malassezia -induced dermatitis, presenting a promising biological therapy strategy for pathogen-associated dermatoses.