Electrospun Nanofiber Wound Dressing Device with On-Demand Antibacterial Release for Infected Diabetic Foot Ulcers

Diabetic foot ulcers are characterized by persistent inflammation, recurrent bacterial infection and impaired angiogenesis, which frequently progress to osteomyelitis and even lower-extremity amputation. Conventional wound dressings often release antibacterial agents in an uncontrolled burst manner and lack the capability to respond to the dynamic infection status of wound beds. This study designs an electrospun nanofiber dressing device with pH-responsive drug delivery functionality. The nanofiber matrix is composed of polycaprolactone and hyaluronic acid, and antibacterial agents are encapsulated within pH-sensitive microcarriers distributed throughout the fibrous network. Under the acidic microenvironment induced by bacterial infection, the microcarriers undergo structural dissociation and trigger targeted drug release; when the wound pH returns to normal, drug release is automatically suppressed. In vitro antibacterial assays demonstrate effective inhibition of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. In a diabetic rat wound model, the dressing accelerates re-epithelialization and granulation tissue formation without obvious cytotoxicity. The main obstacle for clinical translation is the stability of the responsive carrier during sterilization and storage. This smart nanofiber dressing represents a stimuli-responsive therapeutic device for the management of infected chronic wounds.