Chondrogenic differentiation of stem cells in human umbilical cord stroma with PGA and PLLA scaffolds.

The stem cells in the umbilical cord stroma, or Wharton's jelly, are referred to as human umbilical cord mesenchymal stromal cells (hUCMSCs) and have been shown to differentiate along a chondrogenic lineage. The aim of this study was to evaluate the chondrogenic differentiation of hUCMSCs in either polyglycolic acid (PGA) or poly-L-lactic acid (PLLA) non-woven mesh scaffolds for cartilage tissue engineering. PGA is widely known to degrade faster than PLLA, and over longer time scales, and differences may be expected to emerge after extended culture periods. Therefore, the focus of this study was to evaluate differences over a shorter duration. After 21 days of culture in PLLA or PGA scaffolds, hUCMSC constructs were analyzed for biochemical content, histology, and gene expression. Overall, there were only minute differences between the two scaffold groups, with similar gene expression and biosynthesis. The most notable difference was a change in shape from cylindrical to spherical by the PGA, but not PLLA, scaffold group. The overall similar behavior of the groups may suggest that in vivo application of hUCMSC-seeded PLLA or PGA scaffolds, following a 21-day pre-culture period, may yield similar constructs at the time of implantation. However, differences may begin to become more apparent with in vivo performance following implantation, or with in vitro performance over longer time periods.