On the other hand, MSCs possess a great promise to promote the regeneration in hyaline cartilage defects. According to one strategy, in the cell-based treatment of tissue check details defects, cells must be fully differentiated

into the desired cell prior to transplantation. Therefore, in the present study, an attempt was made to evaluate the enhancing Inhibitors,research,lifescience,medical effects of BIO on the chondrogenic differentiation of marrow MSCs. Our results indicated that the presence of BIO in MSC chondrogenic culture accelerates the differentiation. In addition, supplementation of culture, in particular with 0.01 µM BIO, enhanced differentiation. These data would be of help to those involved in functional cartilage engineering, the ultimate goal of which is to elaborate appropriate cartilage constructs for transplantation into articular cartilage defects.29-31 In the present study, the selection of BIO concentration range was, performed according to the previous Inhibitors,research,lifescience,medical reports in which

cell proliferation cultures were treated by BIO. Sato et al.28 reported that the presence of BIO at concentrations less than 1 µM enhanced murine embryonic stem cell proliferation. Similarly, Sinha et al.22 found that the presence of BIO at 0.01, 0.05, and 0.1 µM in culture could increase the proliferation of murine kidney epithelial cells. These reports indicated the positive effect of BIO at the mentioned concentrations on Inhibitors,research,lifescience,medical the cell viability and proliferation, Inhibitors,research,lifescience,medical meaning that the used dosages had no cytotoxic effects. Using similar BIO concentrations, here, we reported that BIO at 0.01 µM could accelerate and enhance the cartilage differentiation of marrow MSCs. These effects of BIO are easily conceivable considering that it belongs to the category of organic compounds referred to as small molecules which are of low molecular Inhibitors,research,lifescience,medical weight capable of binding with high affinity to biopolymers such as proteins, nucleic acids, and polysaccharides altering their activity or function. The most important advantage of small molecules

is that they can rapidly diffuse across cell membranes, reach intracellular sites of action, and specifically target the DNA ligase signaling pathway.32 Furthermore, we found that the treatment of culture with 0.1 and 1 µM Bio could result in the reduced expression of cartilage-specific genes. One logical explanation for this finding would be that 0.1 and 1 µM BIOmight be toxic on MSC culture. This is not in agreement with the previous findings indicating the promoting effects of 0.1 and 1 µM BIO on the viability of cells.22,28 The other explanation could be admitting that these dosages of BIO were not enough to create chondrogenic effects on the MSC cultures. This issue, however, needs further investigations. According to our findings, cartilage-specific genes, including Sox9, aggrecan, and collagen II were in their maximum expression levels at day 14 of the cultures treated with BIO (in particular in 0.