Background: Cutaneous wound healing is a complex process, which can be disrupted by various pro-inflammatory factors within the area. Development of chronic wounds, which stalls in an inflammatory state, is a substantial health care problem with growing number of incidences. Mesenchymal stem cells (MSCs) are somatic stem cells found in various adult tissue. Research have shown that MSCs possess potent anti-inflammatory properties brought on mainly by paracrine mechanisms. Application of MSCs in a novel chronic wound treatment strategy aimed to force the inflammatory state of the injured tissue towards an anti-inflammatory microenvironment is an intriguing future perspective.

Aim: The aim of the present study was to characterize the stem cell phenotype of primary human and rat adipose-derived mesenchymal stem cells (hASCs and rASCs). Furthermore, the adipogenic potential of the cells was investigated.

Methods: Primary ASCs isolated from human and rat abdominal fat tissue were cultured in various induction media in the attempt to induce adipogenesis, osteogenesis, and chondrogenesis. Differentiation was subsequently investigated both histochemically and transcriptionally. Proliferation rate and proportion of colony-forming units in the cell populations were likewise investigated. Lastly, in vitro endothelial cell scratch assays were conducted in order to evaluate the angiogenic potential of the isolated cells.

Results: Adipogenic and chondrogenic differentiation were successful in hASC cultures, whereas only adipogenesis was achieved in rat culture. Both hASCs and rASCs proved to have high proliferative potential as well as being clonogenic in nature. Conditioned medium (CM) harvested from hASC cultures failed to accelerate healing of the endothelial scratch in the in vitro setup. In contrast, application of rASC-CM significantly reduced healing time of the rat endothelial cell monolayer.

Conclusion: In summary, the phenotypical analyses of isolated hASCs and rASCs indicate that the cells were in fact active and viable mesenchymal stem cells. Further attempts on tri-lineage differentiation are, however, necessary in order to validate the multipotency of the cells. The reduced healing time of rASC-CM-treated endothelial cells indicate that the rASCs secrete factors important for angiogenesis, which is relevant for future application of the cells in a diabetic rat chronic wound model.