The Effect of Growth and Differentiation Factor-5 on Two-Dimensional Cultures of Mouse Bone Marrow Stromal Cells

Rupture of the anterior cruciate ligament (ACL) is one of the most common sports-related injuries. However, with its poor healing capacity, surgical reconstruction is currently required to restore its function. Due to serious complications associated with these reconstructions, the use of tissue engineering as an alternative has grown in appeal. Engineering approaches using ligament-derived fibroblasts have been promising but their slow growth rate may limit their practical application. More promising results have been being achieved using stem cells, in combination with appropriate growth factors. As a growth factor, GDF-5 has been shown to play a role in ligament and tendon formation, while bone marrow stem cells have shown promise in their repair. Combining these two parameters, previous work by our group has shown that a combination of GDF-5 and bone marrow stem cells in a 3D environment results in increased expression of several ligament tissue markers. In this study, we continue this work to explore if a dose-response relationship exists between GDF-5 and the stem cell. For this, murine bone marrow stem cells (D1 cells) were exposed to increasing doses of GDF-5 in a standard monolayer culture system and the expression of several ligament genes quantified. In contrast to our previous 3D system, exposing D1 cells to increasing doses of GDF-5 in a 2D culture system did not significantly affect the expression of these markers. Therefore, a more appropriate system for determining the effect of growth factors on stem cells may be a 3D culture system.