iPS cell transplantation in a mouse model – A semiquantitative assessment

Abstract

This study was carried out to determine the effectiveness of induced pluripotent stem (iPS) cell-transplantation as a therapy on wound healing using a splinted wound mouse model. Eighteen clinically healthy female mice were treated with 1μg/g of dexamethasone intramuscular injection once a day for three consecutive days to induce immunosuppression. Under anaesthesia, two sterile wounds were made on shaved backs of each mouse via biopsy punch. With a gap of 20 mm in-between, six injections were delivered once, around the two wounds before the wounds were adhered with splints and wound dressing. The mice were divided into two groups; Group A was given 7 × 105 iPS cells in each injection, and while Group B were injected with 0.9% sodium chloride instead. Wound closure rates were determined through timed scaled photography and analyses with GNU Image Manipulation Program. Three mice from each group were euthanised every 7 days post-wounding, immediately after which wound beds and blood were harvested. Wound beds were fixed, processed, blocked, and sectioned. Sections were stained with H&E; Masson's Trichrome; and immunolabeled for CD31 and CD68; and then examined under a compound microscope subjected to a scoring scheme. From this semiquantitative assessment, Group A sections scored better in angiogenesis on day 7 (p = 0.057), a vital process in the proliferation stage, and hypodermis regeneration on day 21 (p = 0.006), which suggests the wound healing is complete. Together, these findings suggest Group A was ahead in the process of wound healing; although results from lymphocyte count, fibroblast count, granulation tissue, collagen, and wound closure were not statistically significant.