pH-sensitive bilayer electrospun nanofibers based on ethyl cellulose and Eudragit S-100 as a dual delivery system for treatment of the burn wounds; preparation, characterizations, and in-vitro/in-vivo assessment.

A pH-sensitive bilayer electrospun nanofibrous mat containing both antibiotic (gentamicin sulfate, GEN) and non-steroidal anti-inflammatory (diclofenac sodium, DIC) drugs was fabricated for burn wound dressing by electrospinning technique, in which ethyl cellulose (EC) and ethyl cellulose/Eudragit S-100 (EC/ES-100) formed the top and bottom layers, respectively. The fabricated pH-sensitive bilayer electrospun nanofibrous mats were characterized from aspects of both structure and efficiency. Physicochemical properties were investigated via SEM, FTIR, and TGA. The swelling ratio and in vitro drug release of the fabricated nanofibrous mats were studied in different pHs. MTT was applied to assess the safety of the fiber mats. Finally, the in vivo efficiency of the designed pH-sensitive bilayer electrospun nanofibrous mats was examined on the male Wistar rats. Based on the histological analysis and wound healing test (in vivo animal experiments), the (ES100/EC-DIC/GEN)-(EC) pH-sensitive bilayer nanofibrous mat displayed faster wound healing than other bilayer nanofibrous mat. As a result, (ES100/EC-DIC/GEN)-(EC) bilayer nanofibrous mat with pH-responsion could accelerate the burn wound healing process via decreasing the adverse effects of GEN and DIC as topical antimicrobial and anti-inflammatory agents, receptively.