“…In particular, a number of studies have shown that at 14 days, MSC differentiation and subsequent collagen type II gene expression was evident in the presence of TGF-β (Lee et al, 2008, Lisignoli et al, 2005, Bosnakovski et al, 2006, Park et al, 2009. Pellet culture systems are believed to be ideal culture environments to induce chondrogenesis due to the cell-cell contact which mimics the high cell density of embryonic cartilage development and maintains a chondrocytic phenotype (Fan et al, 2008, Chang et al, 2008, Zhang et al, 2010. A study comparing pellet culture and 3-dimensional culture showed that there was a significant increase in collagen type II expression on pellet cultures than on alginate and chitosan beads at day 14 (Bernstein et al, 2009).…”