Effect of microgravity on Ca mineral crystallization and implications for osteoporosis in space

A study of the effect of microgravity on biomineralization/remineralization by considering Ca mineral nucleation under gravity and microgravity is presented. The structure of human bone is determined to a large extent by the turnover of the bone, which included nucleation of biominerals adjacent to biosubstrates. Heterogeneous nucleation will promote a compact bone structure, whereas homogeaneous nucleation will lead to a porous bone structure. Our experimental results show that microgravity will suppress convection, and consequently promote homogeneous-like nucleation during biomineralization/remineralization. This may explain the formation of the porous bone structure under microgavity condition. (C) 2001 American Institute of Physics.