Antimicrobial Nitric Oxide-Releasing Electrospun Dressings\nfor Wound Healing Applications

Abstract

Nonhealing and chronic\nwounds represent a major problem for the\nquality of life of patients and have cost implications for healthcare\nsystems. The pathophysiological mechanisms that prevent wound healing\nare usually multifactorial and relate to patient overall health and\nnutrition, vascularity of the wound bed, and coexisting infection/colonization.\nBacterial infections are one of the predominant issues that can stall\na wound, causing it to become chronic. Successful wound healing often\ndepends on weeks or months of antimicrobial therapy, but this is problematic\ngiven the rise in multidrug-resistant bacteria. As such, alternatives\nto antibiotics are desperately needed to aid the healing of chronic,\nand even acutely infected wounds. Nitric oxide (NO) kills bacteria\nthrough a variety of mechanisms, and thus, bacteria have shown no\ntendency to develop resistance to NO as a therapeutic agent and therefore\ncan be a good alternative to antibiotic therapy. In this paper, we\nreport on the development of NO-releasing electrospun membranes fabricated\nfrom polycaprolactone (PCL)/gelatin blends and optimized to reduce\nbacterial infection. The NO payload in the membranes was directly\nrelated to the number of amines (and hence the amount of gelatin)\nin the blend. Higher NO payloads corresponded with a higher degree\nof antimicrobial efficacy. No cytotoxicity was observed for electrospun\nmembranes, and an <i>in vitro</i> wound closure assay demonstrated\nclosure within 16 h. The results presented here clearly indicate that\nthese NO-releasing electrospun membranes hold significant promise\nas wound dressings due to their antimicrobial activity and biocompatibility.