Preparation and characterization of oleo-gum-resin-loaded electrospun nanofibers and evaluating its wound healing activity in two rat models of skin scar and burn wound.

Background: A growing body of research is dedicated to developing new therapeutic agents for wound healing with fewer adverse effects. One of the proceedings being taken today in wound healing research is to identify promising biological materials that not only heal wounds but also vanish scarring. The effectiveness of nanofibers like polyvinyl alcohol (PVA), in improving wound healing can be related to their unique properties. Desf. subsp. (Zohary) Rech. f. () [Anacardiaceae], also known as "Baneh" in traditional Iranian medicine, is one of the most effective herbal remedies for the treatment of different diseases like skin injuries due to its numerous pharmacological and biological properties, including anti-inflammatory, antioxidant, and anti-bacterial effects.

Purpose: Our study aimed to evaluate the wound-healing activity of nanofibers containing PVA/ oleo-gum-resin in two rat models of burn and excision wound repair.

Material And Methods: PVA/ nanofibers were prepared using the electrospinning method. Scanning electron microscope (SEM) images and mechanical properties of nanofibers were explored. Diffusion and releasing experiments of nanofibers were performed by the UV visible method at different time intervals and up to 72 h. The animal models were induced by excision and burn in Wistar rat's skin and the wound surface area was measured during the experiment for 10 and 21 days, respectively. On the last day, the wound tissue was removed for histological studies, and serum oxidative factors were measured to evaluate the antioxidant properties of the PVA/. Data analysis was performed using ImageJ, Expert Design, and statistical analysis methods.

Results And Discussion: PVA/ nanofibers were electrospun at different voltages (15, 18, and 20 kV). The most suitable fibers were obtained when the nozzle was positioned 15 cm away from the collector, with a working voltage of 15 kV, and an injection rate of 0.5 mm per hour, using the 30:70 w/v gum. In the SEM images, it was found that the surface tension of the polymer solution decreased by adding the gum and yield thinner and longer fibers at a voltage of 15 kV with an average diameter of 96 ± 24 nm. The mechanical properties of PVA/ nanofibers showed that the presence of gum increased the tensile strength and decreased the tensile strength of the fibers simultaneously. results showed that PVA/ nanofibers led to a significant reduction in wound size and tissue damage (regeneration of the epidermal layer, higher density of dermal collagen fibers, and lower presence of inflammatory cells) compared to the positive (phenytoin and silver sulfadiazine) and negative control (untreated) groups. Wound contraction was higher in rats treated with PVA/ nanofibers. Additionally, antioxidative serum levels of catalase and glutathione were higher in the PVA/ nanofiber groups even in comparison to positive control groups.

Conclusion: oleo-gum-resin-loaded electrospun nanofibers potentially improve excision and burn models of skin scars in rats through antioxidative and tissue regeneration mechanisms.