Although survival rates are increasing, burn injuries remain a challenge in the field of cutaneous wound healing. Stem cells have been shown to be a potential new therapy for burns and promote wound healing through a decrease in the inflammation and increase in collagen production. Multipotent adult progenitor cells (MAPC) are a subpopulation of bone marrow-derived stem cells with outstanding self-renewal and differentiation capacity. MAPC cells also secrete a wide range of cytokines which have effects on cellular activities. This study aimed to examine the effects of MAPCs and its secretome on burn injury repair using in vitro and in vivo models.
The effect of MAPC-secretome on the capacity of keratinocytes, fibroblast and endothelial cells to migrate and proliferate was determined in vitro using scratch wound closure and WST1 assay respectively. Secretome-treated fibroblasts were also immunostained for collagen 1 and 3 to investigate its effect on matrix production. Additionally, second degree burns were created on the dorsal surface of mice (n=8/group) and 5 x 105 MAPCs in 100µl PBS were administered via intradermal injection to the wound margins, 24h post-burn injury.
Cells treated with MAPC-secretome showed improved rate of scratch closure and increased proliferation compared to controls. Moreover, fibroblasts treated with MAPC-secretome deposited more collagen 1 and 3. Burns intradermally injected with MAPC cells showed a significant reduction in wound area at day 3 and day 7. Analysis of day 7 burns showed a significant decrease in dermal wound width and increased rate of reepithelialisation.
This study demonstrates the effects of MAPC cell therapy on burn injury repair including reduced time to healing and increased collagen deposition. The beneficial effect of MAPC cells may be due in part to the factors they secrete which improve skin cell proliferation and migration as well as collagen deposition.