Fig. 9. Differentiation of MC3T3-E1 pre-osteoblasts grown on bare and coated Gum alloy. (a) The levels of intracellular ALP activity at 7 and 14 days post-seeding (*p < 0.05 for GNP–SS-coated alloy vs. control substrate at 7 days post-seeding; *p < 0.05 for SS-coated alloy and **p < 0.01 for GNP–SS-coated alloy vs. control substrate at 14 days post-seeding; ***p < 0.001 ALP activity at 14 days vs. ALP activity at 7 days post-seeding). (b) Quantitative colorimetric analysis of extracellular matrix mineralization after 3 weeks of culture; *p < 0.05 for SS-coated alloy, **p < 0.01 for GNP–SS-coated alloy vs. control sample. Results are presented as means ± SD (n = 3).