Etched scaffolds induced hBMSC osteocalcin expression. At various time points, the matrix that formed on the scaffolds was assayed for osteocalcin protein using ELISA. Error bars are S.D. (n = 4). Asterisks indicate significant differences between un-etched and etched scaffolds for 1 d, 7 d and 62 d (t-test, P < 0.05). Osteocalcin did not change significantly over time for un-etched [one-way analysis of variance (ANOVA) with Tukey’s test, P > 0.05]. Osteocalcin changed significantly over time for etched scaffolds and 62 d was significantly higher than 1 d, 7 d and 21 d (ANOVA with Tukey’s test, P < 0.05).