抄録
When mixed cultures of mouse fibroblasts and hydroxyapatite (HA) granules were subjected to various stimuli, the fibroblasts could proliferate in a three-dimensional pattern around the HA granules. In this study, we investigated the effects of two physical stimuli: an electromagnetic field, which is thought to be effective for promotion of bone formation, and ultrasonic waves. Although mixed cultures of mouse fibroblasts and HA stimulated with an electromagnetic field of 1 gauss for 8 hrs or 16 hrs showed only 2-fold higher induction rates of threedimensionallike cell proliferation than that in the untreated control culture, stimulation for 24hrs resulted in 10-fold higher induction rates. Irradiation of cultures with ultrasonic waves of 5 W/cm2 for 3 sec resulted in no induction of cell proliferation, but irradiation for 6 sec and for 9 sec resulted in 4-fold and 5-fold higher induction rates, respectively. The results indicate that the two types of physical stimulus tested in this study have optimal doses to induce the formation of a three-dimensional structure.
