Clustering of hydroxyapatite on a super-twisted collagen microfibril under mechanical tension

Abstract

It is well-known that nucleation and growth of the mineral phase in bone are intimately linked to the interaction between the apatite phase and the collagen matrix at the molecular scale. The exact mechanism of this interaction, however, is not clear due to the challenges involved in experimental characterization at the small size-scale. Herein, we employed molecular dynamics (MD) simulations to investigate the early state of nucleation (i.e. clustering) and growth of apatite clusters on a super-twisted collagen microfibril under mechanical tension in an aqueous solution. The results reveal that mechanical tension (force) facilitates the clustering and growth of the mineral phase on collagen. These results contribute to the understanding of hydroxyapatite (HAP)-collagen interaction and bone biomechanics at the microfibril level.