Quantitative gene expression of PLLA/Col/HA at different time points during the differentiation process.

<p>(a) Gene expression of beta-catenin, frizzled, alkaline phosphatase, and osteopontin. (b) OC (BGALP), osteonectin, Runx2, and Col. (c) Bone sialoprotein, integrin, bone morphogenic protein 2, PP2A (serine/threonine phosphatase), and c-fos. The total RNA was extracted from hMSCs cultured on the substrates (n = 6) at different time points (0, 7, 14, and 21 days) using the RNeasy Mini kit (Qiagen, Chatsworth, CA, USA). Following cDNA synthesis and qPCR, the relative gene expression was normalized to GAPDH and baseline expression. The P value was set at level <0.05 and different alphabets indicate statistically significant groups.