Recently, a collaborative effort between the research teams led by Academician Xu Weilin from the State Key Laboratory of Textile New Materials and Advanced Processing Technology at Wuhan Textile University and Professor Zhu Jia from Nanjing University has resulted in a research paper titled Daytime radiative cooling dressings for accelerating wound healing under sunlight published in the top-tier journal Nature Chemical Engineering, a sub-journal of the Nature series. This research presents a wound dressing with daytime radiative cooling functionality, which prevents wound overheating under sunlight, facilitates the construction of an ideal wound microenvironment, and ultimately achieves rapid wound healing under sunlight. The first author of the paper is Associate Professor Zhang Qian from the State Key Laboratory, while Professor Zhu Jia and Associate Professor Zhu Bin from Nanjing University, along with Academician Xu Weilin from Wuhan Textile University, are the co-corresponding authors.
The wound healing process is closely related to its local microenvironment, including temperature, humidity, and sterility. However, traditional wound dressings lack effective thermal management properties. Under outdoor hot environments, traditional dressings absorb sunlight, leading to a rapid increase in wound temperature, which can easily trigger inflammatory reactions and slow down wound healing. Daytime radiative cooling is a passive cooling technology that emits heat through the atmospheric transparency window into the cold outer space while reflecting a large amount of solar radiation heat, thus achieving cooling. This technology demonstrates great application prospects in energy-saving buildings and personal thermal management textiles by enabling zero-energy sub-ambient cooling under strong sunlight.
In this work, the authors pioneered the introduction of radiative cooling technology into the field of wound dressings. They proposed the use of polyamide 6 with high infrared transparency and biocompatible silk fibroin, and constructed a radiative cooling wound dressing through a layered structure design. The dressing achieves an emissivity of 0.94 in the mid-infrared range and a solar reflectance as high as 0.96, exhibiting excellent daytime radiative cooling optical properties. It can achieve a cooling effect of 7 ℃ lower than the ambient temperature under direct sunlight. Additionally, its micro-nano fibrous network structure design ensures good breathability, moisture permeability, and antibacterial properties. Compared with traditional commercial dressings, this radiative cooling wound dressing can effectively prevent the formation of a hot and humid environment at the wound interface in outdoor hot environments. The results of full-thickness wound repair experiments on mice under direct sunlight showed that the radiative cooling dressing can inhibit wound inflammation and accelerate wound healing. Differential gene expression in RNA sequencing results further validated the function of the radiative cooling dressing in accelerating wound repair under direct sunlight.
Figure: Schematic diagram of the structural design and working mechanism of the daytime radiative cooling dressing for local wound environment management under sunlight.
The layered design in this research enables the daytime radiative cooling wound dressing to possess passive cooling functionality under sunlight, providing an important approach to alleviate wound overheating and accelerate wound healing under sunlight. It also offers inspiration for the design and development of biomedical applications in extreme environments.
