A Multilayered Responsive Dressing for Programmable Exudate Control and Regenerative Therapy of Infected Wounds

Abstract Exudate plays a dual role in wound healing. When present in excess, it can cause tissue overhydration, which aggravates infection and injury. Conversely, insufficient exudate may lead to scarring and impede the healing process. Traditional wound dressings lack the ability to adapt to the changing moisture needs of wounds. To address this, a dynamic phase‐switching smart dressing is developed that dynamically shifts between fluid‐draining and moisture‐retaining modes, helping maintain an optimal healing environment. The dressing consists of three functional layers: a base layer of polypyrrole (PPy) film loaded with a hydrophobic drug (ATRA) on a fabric substrate, a middle layer of porous electrospun polyacrylonitrile (PAN) fibers, and a top layer coated with reactive Mg particles. These layers create a unidirectional fluid pathway due to the asymmetric wettability and pore‐size gradient. Upon contact with exudate, the Mg particles react to form Mg(OH) 2 , increasing local pH and temperature, promoting evaporation, and triggering changes in the PAN and PPy layers that switch the dressing from drainage to retention mode. This exudate‐responsive system manages wound fluids effectively, reduces infection and inflammation, and accelerates healing in infected wounds of rats. The developed multilayered responsive dressing shows potential clinic application in exudate management for complex wounds.