Herbal active ingredient-loaded poly(ω-pentadecalactone-co-δ-valerolactone)/gelatin nanofibrous membranes

Abstract

Recently, there has been an accelerating interest in novel biocompatible wound dressings made of nano-sized materials, especially nanofibers. Electrospun nanofibers provide high surface area and mimic the extracellular matrix which enhances biocompatibility. Besides, nanofibrous structures have high active ingredient loading capacity as a result of their high surface-to-volume ratio and porosity. In the present study, curcumin-loaded poly(ω-pentadecalactone-co-δ-valerolactone)/gelatin (PDL-VL/Gel) nanofibrous membranes were fabricated to be used for healing skin wounds. Poly(ω-pentadecalactone-co-δ-valerolactone) copolymer has been enzymatically synthesized in previous studies, thus it improves the originality of the membrane. It was aimed to obtain a synergetic effect and increase the novelty of the work by blending synthetic and natural polymers. Moreover, it was preferred to provide antibacterial activity by the incorporation of a herbal ingredient (curcumin) as a natural alternative to commercial antibiotics. Varied amounts of curcumin (5-25 %, w:v) were electrospun together with PDL-VL/Gel (equal volume ratio) polymer blend (fiber diameters ranged between 554 and 1074 nm) and several characterizations (morphological and molecular structure, wettability characteristics, and thermal behavior) were applied to examine the curcumin incorporation. Afterwards, in vitro curcumin release studies were carried out and mathematical modeling was applied to release data to clarify the transport mechanism. Curcumin release profiles comprised of an initial burst release in the first hour followed by a sustained release through 24 h. Based on the antibacterial activity test results, 15 % curcumin loading ratio was found to be sufficient for the treatment of skin wounds infected by Gram-negative (E. coli) and Gram-positive (S. aureus and B. subtilis) bacteria. Additionally, nanofibrous membranes did not lead to cytotoxicity, and curcumin content further enhanced the viability of fibroblasts. Thus, the presented antibacterial nanofibrous membrane is suggested to be applied for the treatment of wound infections and accelerating the healing process.