Bionic cooling skin developed for infected wounds

Shi, S., Zhou, H., Ming, Y. et al. Bionic Cooling Skin for Infected Wound Healing. Nano-Micro Lett. 2026; 18:390. https://doi.org/10.1007/s40820-026-02240-6 CC-BY 4.0

Researchers in Hong Kong and mainland China have developed a bionic “cooling skin” dressing that is reported to protect infected wounds, enhance patient comfort, and deliver on‑demand antibacterial activity. The article was published in Nano-Micro Letters.

The team, led by investigators at The Hong Kong Polytechnic University with collaborators at City University of Hong Kong, Jiangnan University and Zhejiang Sci‑Tech University, set out to address a longstanding problem in wound care: the inability of a single dressing to integrate high protective function, comfort, and efficient infection control, particularly in postoperative and traumatic wounds where bacterial colonization can delay healing and increase morbidity. The authors note that conventional gauze, foam, and hydrocolloid dressings all have drawbacks, either adhering to tissue, adding cost, or proving unsuitable for infected wounds.

The dressing they designed is built as a hierarchical Janus nanofibre membrane based on electrospun polyvinylidene fluoride (PVDF), combined with single‑sided metal–organic frameworks (MOFs), specifically Fe‑modified zeolitic imidazolate framework‑8 (Fe‑ZIF8), that generate visible light‑responsive reactive oxygen species. Solvent welding creates physical bonding points between the nanofibres, yielding mechanical properties that closely mimic natural human skin. The hydrophobic outer layer reflects sunlight and emits mid‑infrared radiation to lower surface temperature, and a hydrophilic inner layer wicks moisture and anchors Fe‑ZIF8 nanoparticles for antibacterial function.

Under simulated sunlight, the dressing reduces surface temperature by about 4°C compared with non‑Janus controls, and in vivo rat studies showed an average cooling of 1.7 °C under realistic outdoor irradiance. Air permeability exceeds 1.8 mL s⁻¹ and water vapour transmission surpasses 12.5 kg m⁻² d⁻¹, while particle filtration efficiency is reported above 99.8%, indicating a balance of barrier protection and breathability. Fe doping narrows the ZIF8 bandgap to 2.56 eV from 5.15 eV, enabling visible‑light absorption and photocatalytic reactive oxygen species generation. In infected wound models, the dressing achieved 97.1% antibacterial efficacy against Staphylococcus aureus under white light, comparable to antibiotic‑treated controls and maintained fibroblast biocompatibility over five days.

RNA sequencing and qPCR analyses suggest the material not only covers wounds, but upregulates angiogenesis‑related genes (including Vcam1 and several Vegf isoforms), cell migration markers, and antimicrobial peptides while downregulating inflammatory mediators such as TNF‑α. The authors reported that histology shows uniform collagen deposition and increased epidermal thickness consistent with robust tissue regeneration without excessive scarring. In animal models, wounds treated with the bionic cooling skin approached complete closure within 11 days, with healing rates more than twice those observed in untreated or standard PVDF groups.

“This innovative bionic wound dressing not only enhances comfort and healing efficacy but also advances our understanding of wound repair mechanisms, holding significant promise for future wound care and biomedical material design,” the authors wrote.