Here is provided a novel differentiation protocol, which was experimentally shown to give rise to osteoprogenitor cells in vitro. A novel medium composition containing a p38 MAPK inhibitor was found to promote differentiation of human adipose stem cells (hASCs) to osteoprogenitor cells. The early osteogenic precursor cells may further differentiated to osteoblasts. With the present method, it can be produced cells, expected to contribute to treatment and research of conditions, diseases, pathologies, transplant techniques as well as toxicology and drug development related to the skeletal system.
