Numerical investigation of the role of osteopontin on the mechanical strength of biological composites

The material components and configurations inside biological materials (e.g. bone and tooth) are quite dissimilar compared to conventional engineering materials. Besides hydroxyapatite minerals and collagen proteins, non-collagenous proteins such as osteopontin are also a very important component in bone. The aim of this paper is to study the role of osteopontin on the mechanical strength of biological composites. The MD simulations were performed to investigate the failure energy of osteopontin in two different directions, i.e. the direction normal to surface (thickness direction) and the direction tangential to surface (interface direction). The FE simulations were then performed to investigate the effects of failure energy in different directions on biological composites. The results show that the failure energy of osteopontin is higher in the interface direction. Significant improvement in the mechanical behaviour of biological composites is also found with the increased failure energy in the interface direction. Contrarily, although lower failure energy of osteopontin is observed in the thickness direction, but it is also found that the mechanical behaviour of biological composites does not greatly affected by the failure energy in the thickness direction. The numerical investigation provides important insights into how the osteopontin affects the mechanical behaviour of biological composites.