The current study was designed to study the persistence and distribution of caprine bone marrow derived mesenchymal stem cells (cBM-MSCs) when administered intra-dermally in experimentally induced cutaneous
wounds in rabbits. MSC's from goat bone marrow were isolated and their differentiation potential towards adipogenic and osteogenic lineages were assayed in vitro. The isolated cells were phenotypically analysed using flow cytometry for the expression of MSC specific matrix receptors (CD73, CD105 and Stro-1) and absence of hematopoietic lineage markers. Further, these in vitro expanded MSCs were stained with
PKH26 lipophilic cell membrane red
fluorescent dye and prepared for
transplantation into cutaneous
wounds created on rabbits. Five, 2 cm linear full thickness skin incisions were created on either side of dorsal midline of New Zealand white rabbits (n = 4). Four
wounds in each animal were implanted intra-dermally with
PKH26 labelled cBM-MSCs suspended in 500 µl of
Phosphate Buffer Saline (PBS). Fifth
wound was injected with PBS alone and treated as negative control. The skin samples were collected from respective
wounds on 3, 7, 10 and 14 days after the
wound creation, and cryosections of 6 µM were made from it. Fluorescent microscopy of these cryosections showed that the
PKH26 labelled transplanted cells and their daughter cells demonstrated a diffuse pattern of distribution initially and were later concentrated towards the
wound edges and finally appeared to be engrafted with the newly developed skin tissues. The labelled cells were found retained in the
wound bed throughout the period of 14 days of experimental study with a gradual decline in their intensity of red fluorescence probably due to the
dye dilution as a result of multiple cell division. The retention of transplanted MSCs within the
wound bed even after the complete wound healing suggests that in addition to their paracrine actions as already been reported, they may have direct involvement in various stages of intricate wound healing process which needs to be explored further.