Effects of Low Intensity Ultrasound Stimulation on the Proliferation of Alveolar Bone Marrow Stem Cells

摘要

Low-intensity ultrasound stimulation produces significant multi-functional effects that are directly relevant to bone formation. It was previously found that low-intensity ultrasound stimulation enhanced bone regeneration although the exact cellular mechanism is not clear. The aim of the present study is to investigate the effect of low-intensity ultrasound stimulation on proliferation of alveolar bone marrow stem cells. Before low-intensity ultrasound stimulation, alveolar bone marrow stem cells were cultured for 24h to facilitate their attachment. The cells were cultured in medium with or without low-intensity ultrasound stimulation. The ultrasound frequency was 1 MHz. Cell cultures stimulated with ultrasound were conducted by three treatment groups - group 1: intensity (100, 200, 300, 400 and 500 mW/cm2), group 2: duty cycle (5, 10, 30 and 50%) and group 3: duration time (1, 3, 5, 10, 20 and 30 mm). The effects of low-intensity ultrasound stimulation were evaluated by cell number and morphological changes. The proliferation rates of alveolar bone marrow stem cells for the particular stimulated groups were larger than those of control groups. After low-intensity ultrasound stimulation (intensity: 100 mW/cm2, duty cycle: 30% and duration time: 10min), the alveolar bone marrow stem cell counts were significantly increased (p<0.05). This study suggested that the cell growth could be enhanced by appropriate low-intensity ultrasound stimulation.