Computational design for scaffold tissue engineering

Structure of tissue scaffold plays a critical role in guiding and supporting cell proliferation and differentiation. One widely accepted way to create a desirable biomechanical environment is to have it match the mechanical and biological properties of native host tissue. However, conventional design process typically involves laborious trial and error, and it is sometimes very difficult to achieve the desired biomimeticity when multiple criteria are involved. This chapter aims to present a systematic methodology for the design of tissue scaffold structures, in which the stiffness and diffusivity criteria are taken into account to address various biomechanical requirements in tissue engineering. The scaffolds with periodic microstructures are considered herein, which can be fabricated using 3D printing or additive manufacturing technologies. In this design process, the finite element (FE)-based homogenisation technique is employed to characterise effective material properties, and topology optimisation is carried out using the inverse homogenisation technique, in which (1) bulk modulus, (2) diffusivity and (3) their combination are formulated as the design objectives. To assess the optimised design, we simulate and examine the bone tissue regeneration inside the scaffolds under certain biomechanical conditions in two different models, specifically Wolff’s remodelling and the mechanobiology rules. The tissue regeneration results demonstrate how different design criteria lead to different outcomes, signifying the importance of scaffold design and the proposed methodology.