| Objective To explore the optimal concentration of the lactoferrin (LF) for the stimulation of rat osteoblast proliferation and the best time to promote osteoblast differentiation using 1000μg/ml lactoferrin. Methods Primary rat osteoblasts were harvested with mixed enzyme from neonatal calvaria of Sprague Dawley rats and then cultured. After the treatment with different concentrations of LF (0, 0.1, 1, 10, 100, 200, 400, 600, 800, and 1000 μg/mL) for 1, 3, 5, and 7 days, the cell proliferation was analyzed using CCK-8 methods. After the treatment with LF of 1000μg/mL for 7, 14, and 21days, alkaline phosphatase staining method was used to evaluate the ALP activity of the osteoblast. Results 1) The results of cell proliferation with CCK-8 method showed that below 100 μg/mL concentration of LF, OD value increased as the concentration increased. However, OD value decreased with the concentration of LF increased using over 100 μg/mL concentration of LF. 2) The results of ALP staining showed that the highest ALP activity was achieved on the 21st day using 1000 μg/mL concentration of LF. Conclusion The best concentration of LF for rat osteoblast proliferation is 100 μg/mL. LF of 1000 μg/mL promotes osteoblast differentiation in a time dependent manner. |