Abstract
Mechanical stimulation to bones affects bone formation such as decrease of bone mass of astronauts under zero gravity, walking rehabilitation to bone fracture, and fracture repair with ultrasound devices. Bone cells have been reported to sense and response to mechanical stimulation at cellular level morphologically and metabolically. In the view of mechanical vibrations, bone cells are deformed according to mechanical stimulation and their mechanical characteristics. In this study, sinusoidal inertia force was applied to cultured osteoblasts, which are a type of bone cells, and effects of mechanical vibration duration at 0.5 G and 25 Hz on the cells were investigated in respect of the cell proliferation and alkaline phosphatase (ALP) gene expression. The results to be obtained are as follows. With respect to the cell proliferation, cell saturation density monotonically increased with mechanical vibration duration. With respect to ALP gene expression, bone generation was significantly promoted at the 12 h/day vibration group.
