Nanofibers for improving the wound repair process: the combination of a grafted chitosan and an antioxidant agent

Abstract

Wound healing, a complex process involving several important biomolecules and pathways, requires efficient dressings to enhance the therapy effects. Electrospinning nanofiber mats for wound healing have attracted significant interest because of their unique properties including ultrathin diameters, high volume ratios, and three-dimensional structure that mimics the extracellular matrix. In this study, we synthesized grafted chitosans with improved solubility, resulting in circumventing the use of acidic solvents, such as acetic acid and trifluoroacetic acid, simplified the electrospinning processes and fabricated poly(vinyl alcohol)-free nanofibers. The model drug curcumin was encapsulated in the nanofibers, consisting of grafted chitosan and poly(propylene carbonate), by electrospinning, which gradually released the drug from the matrix in 288 hours. Moreover, the curcumin-loaded composite nanofibers showed excellent free-radical scavenging capabilities. The enhanced wound healing efficacy was confirmed by an in vivo test and approximately 100% wound closure ratio was observed in the 10% curcumin-loaded PPC/g-CS nanofibers group at day 21 post surgery, which was subsequently evidenced by haematoxylin and eosin stain and Masson's trichrome stain. Higher granulation scores and higher collagen contents were observed in the PPC/g-CS 10% curcumin group, showing significant differences among all the groups. These results demonstrated that the combination of grafted chitosan and curcumin improved the wound healing process. Moreover, electrospinning nanofibers based on the grafted polymer and curcumin showed potential for wound repair applications.