Osteogenic Effect of Magnesium on Normal Human Osteoblasts

Objectives: Magnesium-containing biomaterials have been used in applications for bone regeneration and dental/orthopedic implants. However, the mechanism underlying the biologic effects of magnesium is still disputable. In addition, osteogenic effect of magnesium has been reported on ATCC osteosarcoma cell lines but not on normal human osteoblasts. This study was designed to test the effects of magnesium on cell attachment efficiency and proliferation of normal human osteoblasts.
Methods: Normal human osteoblasts derived from human alveolar bone were cultured in triplicate in growth media with different concentrations of supplemental magnesium: 0.25mM, 0.5mM, 1mM, 2mM and 4mM as the study groups and 0mM as a control group for the time intervals of 16 hours for cell attachment efficiency and 7 days, 10 days and 14 days for cell proliferation rate by measuring the optical density of crystal violet dye stained cells and being normalized by the baseline of attached cells at 16 hours. Statistical analysis was done using ANOVA and Tukey HSD post-hoc tests.
Results: Cells with 2mM supplement magnesium showed significant higher attachment efficiency than control (1.5 folds, p<0.01) and other magnesium groups (p<0.05). Cells with 2mM and 4mM supplement magnesium showed significant higher cell proliferation rates than control at 10 days (p<0.05) and at 14 days (p<0.01) and slightly higher than cells with 0.25mM, 0.5mM and 1.0mM supplement magnesium.
Conclusions: Proliferation rates of normal human osteoblasts could be significantly upregulated by 2mM and 4mM supplement magnesium while attachment efficiency of normal human osteoblasts could be upregulated by 2mM supplement magnesium. These data from the study on normal human osteoblast could be more clinically relevant and useful for better understanding and selection of magnesium-containing osteogenic materials for bone tissue regeneration and implants.