The establishment of a mechanobiology model of bone and functional adaptation in response to mechanical loading

Abstract

Background Mechanical stimuli affected bone adaptation, however, the mechanism on a dose–response relationship between mechanical stimuli and bone response is unclear. Therefore, we established a mechanobiology model to evaluated the adaptive response of bone to strain deformation at high-frequencies (5–15 Hz) of externally applied strain. Methods The ulnae of adult female rats were subjected to dynamic axial loading in vivo using Instron materials-testing machine. The applied loading at frequencies of 5 Hz, 10 Hz, and 15 Hz for 10 min with a haversine, low-magnitude waveform for a 2 weeks period, the peak strains is 2000 με and 3000 με. Strain was recorded using strain gauge conditioner and compared to physiological values obtained after testing. Findings At frequencies of 10 Hz, 15 Hz groups, loading promoted obviously secreted of osteocalcin and collagen; a relative benefit in Bone Mineral Density (BMD) was found compare to the control ( P < 0.05) followed the decline of material mechanical properties (modulus of elasticity, ultimate stress) ( P < 0.01). Interpretation These data show that a mechanobiology model of the axial ulna loading technique had been established successfully in rat. A short daily period of low-magnitude, high-frequency mechanical stimuli results in an osteogenic response related to peak strain magnitude, which do not result in significant differences in mechanical properties between the groups.