LPLI promotes osteogenesis in D1 cells. D1 cells were cultured in BM (negative control) or OIM (OIM-control), or D1 cells were cultured in OIM and treated with LPLI at 2 J/cm² (OIM-2 J/cm²) or 4 J/cm² (OIM-4 J/cm²).

<p>(<b>A</b>) The ALP activity of D1 cells was analyzed. LPLI at both 2 J/cm² and 4 J/cm² significantly increased the ALP activity at days 3 and 5 (n = 6). (<b>B</b>) D1 cells were cultured for 10 or 14 days. Following fixation, the cells were stained with Alizarin Red S. A pronounced dose-dependent increase of mineralization was observed at both day 10 and day 14 (n = 6). (<b>C</b>) Relative quantification of the Alizarin Red S staining shown in B (n = 6). The following statistical significance levels were applied: * p<0.05, ** p<0.01, and *** p<0.001 compared with the OIM-control group.