The epitope characterisation and the osteogenic differentiation potential of human fat pad-derived stem cells is maintained with ageing in later life

Some clinical settings are deficient in osteogenic progenitors, e.g. atrophic nonunited fractures, large bone defects, and regions of scarring and osteonecrosis. These benefit from the additional use of bone marrow-derived mesenchymal stern cells, but these cells exhibit an age-related decline in lifespan, proliferation and osteogenic potential-Therapeutic approaches for the repair of bone could be optimised by the identification of a stem cell source that does not show age-related changes. Fat pad-derived stern (ells are capable of osteogenesis, but I detailed study of the effect of ageing oil their epitope profile and osteogenic potential has so far not been performed. Fat pad-derived cells were isolated from groups of 5 patients with a mean age of 57 years (S.D. 3 years) and 86 years S.D. 3 years). The proliferation, epitope profile and osteogenic differentiation potential of cells from the 2 groups were compared. Cells isolated front the fat pad of both groups showed similar proliferation rates and exhibited a cell surface epitope profile similar but not identical to that of hone marrow-derived stem cells. The cells from both groups cultures in osteogenic medium exhibited osteogenesis as shown by a significant upregulation of alkaline phosphatase and osteocalcin genes, and phosphatase enzyme activity compared to Cells cultured in the control alkaline medium. The cells cultured In the osteogenic medium also showed greater calcium phosphate deposition on alizarin red, staining. There was no significant different between the osteogenic potential of the two age groups lot any of the parameters studied. The fat pact is a consistent and homogenous source of stem cells that exhibits osteogenic differentiation potential wit h no evidence of any decline with ageing in later life. This has many potential therapeutic tissue engineering applications for the repair of bone defects in an increasingly ageing population. (C) 2008 Elsevier Ltd. All rights reserved.