A Multifunctional Janus Electrospinning Dressing with Sequential Drug-releasing Property for Programmed Treatments of Chronic Infected Wounds.

Wound dressings equipped with disinfection and wound tissue regeneration capabilities demonstrate significant potential in chronic wound management. However, current multifunctional dressings can rarely accommodate multiple repair processes accurately due to the time-dependent variational wound microenvironment. Herein, a Janus wound dressing is developed based on electrospun nanofibrous scaffold featuring programmed drug release performance and asymmetrical wettability. Specifically, polyvinylidene fluoride (PVDF) nanofiber membrane as the outer layer to resist the external biofouling and provide essential mechanical support for the inner layer was firstly constructed. Subsequently, the inner layer composed of polyvinyl pyrrolidone (PVP) and polylactic acid (PLA) fibers which are separately loaded with bacterial-targeted nanoparticles (VHA NPs) and composite particle of zeolite imidazolate frameworks-8 containing deferoxamine (ZD NPs) is fabricated on the PVDF membrane. Experimental results demonstrated that the degradation rate of the inner layer could be precisely controlled to sequentially deliver the loaded drugs into the wound site. Taking advantages of the synergistic therapeutic effects including significant antibacterial activity, admired antioxidant property and remarkable angiogenesis performances, the fabricated Janus dressing (PF/PHPD) achieves superior performance for promoting infected wound healing in a full-thickness skin wound model, much better than that of conventional bandage and clinical antibiotic treated wound.