جداسازی سلول‌های بنیادی مزانشیمی از مغز استخوان موش با تعویض مداوم محیط کشت

Background: MSCs have been isolated from a variety of mammals by the plastic adherence method. However, this method can be problematic due to the unwanted growth of hematopoietic cells and non-MSCs. The potential of MSCs to differentiate along multiple lineages is the key to the identification of stem cell populations in the absence of molecular markers. In the present study, we describe a homogeneous population of MSCs from mouse bone marrow isolated using an improved plastic adherence method that employs frequent medium change (FMC) at the initial hours of harvested bone marrow cell culture. Methods: Balb/c mice were sacrificed and whole bone marrow cells were aspirated from the femur and tibia and then cultivated in six-well plates. After 3-4 hours of culture, old medium was removed and fresh medium was added. FMC was performed every eight hours over a 72 hour period. When primary cultures became nearly confluent, the first passage was performed. These cells were then used for further examination. To investigate their mesenchymal nature, the cells were allowed to differentiate into mesenchymal lineages and examined at each passage up to the tenth passage for surface antigens by flow cytometry.Results: We achieved purified populations of fibroblast-like cells in the two weeks after culture initiation. The cells were capable of differentiating into osteocytes and adipocytes. Isolated MSCs were reactive to the CD44, Sca-1, and CD90 cell surface markers. MSCs were negative for hematopoietic surface markers such as CD34, CD11b, CD45, CD31, CD106, CD117 and CD135.Conclusions: This protocol provides an efficient isolation of homogeneous populations of MSCs from mouse bone marrow.