The influence of cultivation conditions on the proliferation and differentiation of rat bone marrow multipotent mesenchymal stromal cells

Rat bone marrow multipotent mesenchymal stromal cells (rBM MMSCs) demonstrate a potential to differentiate down the mesodermal pathway but under appropriate experimental condition differentiation into non-mesodermal lineages may occur. Knowing this fact it seems interesting whether prolonged cultivation and preservation affects BM MMSC morphology, differentiation ability into multiple lineages and proliferation capacity. Therefore this study was aimed to investigate the effects of long-term cultivation and cryopreservation on the morphology, proliferation and differentiation potential of rat bone marrow-derived MMSCs in vitro. The effects of long term cultivation and cryopreservation were evaluated by the phenotype and morphology of the cell population. Findings show that the 60^th passage cells had a smaller, more flattened and spindle-shaped morphology than the 4^th passage cells before and after cryopreservation. We have also found that the 60 ^th passage cells were more proliferative than rBM MMSCs in early passages but the ability to differentiate was more effective in the 4 ^th passage cells before cryopreservation. rBM MMSCs from pre- and post- cryopreservation had similar colony formation potential and cellular morphology but disparity in differentiation potential was observed. The results of the present study provide evidence that rBM MMSCs could be cryopreserved without noticeable loss of viability and proliferative capacity but the differentiation capability may be affected.