Mesenchymal Stem Cell Purification from the Articular Cartilage Cell Culture

Objective Articular cartilage as an avascular skeletal tissue possesses limited capacity to heal. On the other hand, it is believed that the regeneration capacity of each tissue is largely related to its stem cell contents. Little is known about the presence of mesenchymal stem cells in articular cartilage tissue. This subject is investigated in the present study. Materials and Methods Articular cartilage was obtained from rats of Wistar strain and subjected to enzymatic digestion using 1:1 ratio of 0.2% collagenase I and 0.1% pronase. The released cells were then collected and cultivated in 25 cm2 culture flask, which was resulted in the appearance of two morphologically distinct cell populations. Fibroblastic population were purified and expanded through several subcultures, using their loose adherence on culture surfaces and examined in terms of differentiation potential. Results The primary culture mainly contained polygonal cells with few fibroblastic cells among them. Upon the first subculture, the fibroblastic cells appeared as aggregates of few cells among the polygonal cartilage cells. It was found that the fibroblastic cell population could easily detach from the culture surface following to a brief exposure to tripsin solution. Using this property, these cells purified and expanded by several subcultures. According to the results, the isolated cells were able to easily differentiate into chondrocytic, osteocytic and adipocytic cell lineages. Conclusion It seems that articular cartilage contains a distinct fibroblastic cell population with mesenchymal stem cell nature. These cells can be purified and expanded by cell culture methods, thanks to their loose adherence on the culture dish surfaces.