Versatile Janus dressing with radiative cooling and exudate control for outdoor wound management.

Prolonged outdoor exposure to sunlight and infrared radiation induces localized wound overheating and excessive exudation, aggravating inflammation and infection while significantly impeding healing. Regrettably, most existing wound dressings lack the essential functionalities to facilitate healing under such conditions. To address this limitation, we develop a multifunctional Janus dressing by continuous electrospinning, incorporating PVDF-b-PTFE, polyvinylpyrrolidone, and TiO2 nanoparticles. The synergistic interaction among these components endows the dressing with a solar reflectivity of 99.8% and a mid-infrared emissivity of 98.7%, enabling a sub-ambient cooling effect that reduces the temperature by up to 17.6 °C under direct sunlight. This effect is beneficial in preventing overheating and the associated complications of wounds. Meanwhile, the photocatalytic activity of TiO2 nanoparticles under sunlight provides the dressing with superior antibacterial capability (nearly 100% antibacterial rate), which mitigates infection risks. Furthermore, the hierarchical structure confers asymmetric wettability and achieves effective exudate management. Thanks to these multifunctional attributes, the Janus dressing significantly accelerates the healing of sunlight-exposed wounds, as validated in a rat full-thickness skin defect model under high-temperature sunlight. Collectively, this work not only tackles wound overheating in outdoor settings but also provides an innovative strategy and a theoretical foundation for the development of intelligent wound dressings.