Effects of exosomes derived from fibroblast cells on skin wound healing in Wistar rats

Abstract

Background: The role of exosomes in areas, such as skin wound healing, have been of consideratble interest recently. However, the effects of exosomes derived mainly from fibroblast cells on wound healing have yet to be documented well. The study aimed to evaluate the effects of exosomes derived from fibroblast cells on wound healing in Wistar rats.

Methods: Human fetal skin was isolated afterward centrifuge, and trypsin 0.1% was added to the cells after removing DPBS from the Falcon tube, and the trypsin was removed. The cells were moved to culture flasks. Then, the secondary culture of Human Fetal Skin Fibroblast was done. The pellets containing exosomes were suspended in PBS, and to achieve purified exosomes, the suspended Exosome were passed through a 0.22 µm filter. The exosome solution was kept at - 20 ºC. In the in vivo phase, 48 male Wistar rats were divided into four groups. Group I, low-dose exosome (LDE) solution (150 μl/day), group II high-dose exosome (HDE) solution (300 μl/day), group III commercially available ointment (positive control (PC)) was topically applied on wounds and group VI without treatment (negative control (NC)). A skin biopsy was taken for histopathological analysis. Wound area, depth of ulcer, degree of granulation, and inflammation were assessed. For histopathological assessment, re-epithelialization, inflammatory cells, granulation tissue, crust formation, and collagen maturation (fibrosis) parameters were evaluated.

Results: Forty-eight male Wistar rats were included. The HDE group's showed accelerated healing compared to the NC and PC groups at 9 and 12 days. Inflammation and granulation were higher in the HDE, LDE, and PC groups than in the NC group (p < 0.05). The onset of re-epithelialization and collagen deposition was higher in the LDE, HDE, and PC groups, then on nine and 12-day, gradually maturing and extending through the ulcer (p < 0.05). On day 12, in almost all parameters, the LDE and HDE groups showed improved results compared to NC cases (p < 0.05).

Conclusions: The results showed that the utilization of fibroblast-Exo significantly promoted cutaneous wound healing in a rat full-thickness skin ulcer model. This is a potential innovation for cell-free therapy from fibroblast-Exo as a closed structure similar to human cells.

Keywords: Skin; Stem Cell; Trauma.