Mesenchymal stem cells promote incision wound repair in a mouse model

Purpose: To investigate the wound healing process via the application of mesenchymal stem cells (MSCs) in a mouse model.
Methods: MSCs were collected from the bone marrow of the femur and tibia of 6 – 12-week-old C57BL/6 mice. Full-thickness cutaneous wounds (4 × 2 cm) were made by incision on the dorsal side of the mice. The wound was then subjected to one of four random treatments: phosphate-buffered saline (PBS) solution, 3T3 fibroblasts, naive MSCs, or interferon gamma-activated MSCs. Chalkley method was used to determine vascular density. A score was given, for each field examined, for CD31-positive areas, and the results of blind analysis were confirmed by independent analysis of a second evaluator.
Results: The tensile strength of the wound area was significantly lower in older versus younger mice (p ≤ 0.0007). Only one quarter of the mean force was required to disrupt wound integrity in older mice compared to young mice. Treatment with MSCs showed positive effects on wound healing. Activated MSCs showed the greatest efficacy at a dosage of 5 × 10⁴ activated MSCs/8 cm² of wound area or 6, 250 cells/cm².
Conclusion: The results suggest that MSC therapies enhance the tissue regeneration capacity in mice, especially in older populations, through effective transdifferentiation into the epithelium.