Bioactive antibacterial bilayer PCL/gelatin nanofibrous scaffold promotes full-thickness wound healing

Abstract

Treatment of diabetic, chronic, and full-thickness wounds is a challenge as these injuries usually lead to infections that cause delayed and inappropriate healing. Therefore, fabrication of skin scaffolds with prolonged antibacterial properties are of great interest. Due to this demand, bilayered nanofibrous scaffolds were fabricated based on polycaprolactone and gelatin. The top layer of these scaffolds contained amoxicillin as a model drug and the bottom layer was loaded with zinc oxide nanoparticles to accelerate wound healing. Several characterization techniques including FTIR, SEM, swelling, tensile test, in vitro degradation, drug release, antibacterial activity, and MTT assay were used to assess physical, mechanical, and biological properties of produced nanofibers. SEM results demonstrated that bilayered scaffolds have smooth bead-free microstructures while in vitro release test showed that samples have a sustained release for amoxicillin up to 144 h (tested time). Disk diffusion assessment confirmed the potency of scaffolds for hindering bacterial growth while results of cytotoxicity evaluation revealed that scaffolds could effectively accelerate cell proliferation. Finally, in vivo tests on full-thickness rat models revealed that fabricated nanofibers accelerate wound contraction, increase collagen deposition and angiogenesis, and prevent scar formation. Altogether, results showed that fabricated scaffolds are promising candidates for treatment of full-thickness wounds.

Keywords: Drug delivery; Electrospinning; Gelatin; Nanoparticles; Polycaprolactone; Wound healing.