Fig. 5.

Biological assessment: (a) Fluorescence images of MC3T3-E1 osteoblasts cultured on Ti, NS1, NS2, NS3, and NS4 for 24 h; (b) Fluorescence images of MC3T3-E1 osteoblasts after irradiation with 808 NIR light at 0.8 W cm⁻² for 15 min; (c) Fluorescence images of NIR light irradiated MC3T3-E1 osteoblasts after re-culturing for 24 h; (d) Cell proliferation measured by MTT after culturing for 1, 3, and 5 days; (e) Quantitative ALP activity; (f) Collagen secretion; (g) ECM mineralization of MC3T3-E1 on Ti and NS4 on the 4^thand 7th day; (h) Osteogenisis-related genes RUNX2 and OCN expressions on Ti and NS4 (*p < 0.05, **p < 0.01).