Multiscale Modelling of Bone Tissue – Remodelling and Application to Scaffold Design

In tissue engineering design it is in general hypothesised that the scaffold should provide a mechanical environment similar to the pre-degenerative one for initial function and have sufficient pore interconnectivity for cell migration and cell/gene delivery. In the case of bone tissue, the design of such scaffolds can be greatly improved by the knowledge of the bone adaptation pro9 cess thus facilitating the identification of scaffold microstructures compatible with the properties of real bone. In this chapter we present a multiscale model for bone adaptation that potentially can respond to some of the scaffold design requirements. The proposed model focuses on the two top scale levels of bone architecture. The macroscale (whole bone) characterized by the bone apparent density distribution and the microscale where the trabecular structure of bone in terms of its mechanical properties is characterized. At global scale bone is assumed as a continuum material characterized by equivalent mechanical properties. At local scale the bone trabecular anisotropy is approached by a locally periodic porous material. The relevance of incorporating a micro design scale relies on the possibility of controlling morphometric parameters that not only characterize trabecular structure, and thus can help the design of bone substitutes, but also allow a fine balance between bone tissue biological and mechanical functions.