Thermo‐Responsive Trilayered Fibrous Dressing with Liquid Gate for Dynamical Exudate Regulation and Wound Moisture Balance

Abstract

Exudate plays a crucial role in wound healing, but an excessive amount can lead to over‐hydration of tissue and aggravating the infection and the injury. On the other hand, inadequate exudate can cause scarring and hinder healing. Traditional wound dressings are unable to regulate exudate levels based on the specific needs of the wound. To address this issue, a liquid‐gated trilayered fibrous wound dressing capable of pumping fluid in a temperature‐dependent manner is developed. This dressing comprises a hydrophilic cotton layer, a thermo‐sensitive (TPPU) layer, and a hydrophobic layer of polyurethane (PU) nanofibers. The TPPU layer is constituted by nanofibers that are composed of an upper critical solution temperature (UCST)‐type polymer, PU, and silver nanoparticles. The intermediate TPPU layer exhibits changes in its wettability upon heating, adjusting the thickness of the hydrophobic layer and ultimately achieving the appropriate structure for guiding spontaneous fluid transport. The positive effect of this novel dressing on diabetic wounds is observed, as it enhanced epithelialization and collagen synthesis while reducing inflammation, ultimately accelerating the wound healing process. This dressing has the potential to provide a groundbreaking solution for managing exudate, achieving moisture balance and promoting wound healing in clinical settings.