Engineered Janus amphipathic polymeric fiber films with unidirectional drainage and anti-adhesion abilities to accelerate wound healing

Rational design of new wound dressing materials aims to accelerate wound healing. Traditional hydrophilic wound dressings, however, tend to cause retention of wound exudate retention, which increases the risk of bacterial infection, resulting in slower wound healing. Herein, a multifunctional amphiphilic wound dressing nanofibrous materials with Janus superhydrophilic/ superhydrophobic feature is designed to accelerate wound healing. In this design, the top superhydrophilic polycaprolactone (PCL)-Gelatin (PCL-Gelatin, WCA ~ 0°) fibers function as a pump-like suction layer that can effectively isolate wound exudate from the wound site, thereby providing drier condition which lowers the risk of wound infection. More importantly, the superhydrophobic PCL-poly(perfluorodecyl methacrylate)-block-poly(dimethylsiloxane)-block-poly(perfluorodecyl methacrylate) (PFMA-b-PDMS-b-PFMA) (PCL-PFMA, WCA ~ 140°) in contact with the wound site showed excellent anti-adhesion effect to bacterial, cells and tissues, thereby further lowering the risk of bacterial infection and preventing the secondary injuries caused by dressing changes. Sprague-Dawley (SD) rat skin lesion model demonstrated significant improvement in wound healing of the Janus amphipathic PCL-Gelatin / PCL-PFMA fiber films compared with the conventional hydrophilic- and hydrophobic-only wound dressing materials. After 14 days of treatment, the wound healing area in this group was close to 100%. To the best our acknowledge, this is a pioneer exploration of Janus amphipathic wound dressing with unidirectional drainage function and anti-adhesive ability, which may have great potential for real life usage on clinical patients.