Figure 4: Osteogenic gene expression profiles. Induction of the ALP (a and b) and bone sialoprotein (c and d) gene expression on the uncoated, SP-coated, and Ln2-P3-coated commercially pure (c.p.) titanium (Ti) surfaces at days 1 and 7, respectively. Expression of the osteogenic marker genes was determined by real-time RT-PCR. Note that the expression levels are the highest on the Ln2-P3-coated surface both at day 1 and at day 7, as compared with the uncoated and SP-coated surfaces. Data are expressed as the mean ± standard deviation (n = 3). Ti, Ti + SP, and Ti + Ln2-P3 on the graphs mean the uncoated, SP-coated, and Ln2-P3-coated c.p. Ti surfaces, respectively.