Triply Periodic Minimal Surfaces Sheet Scaffolds for Tissue Engineering Applications: An Optimization Approach toward Biomimetic Scaffold Design.

Biomimetic scaffold design is gaining attention in the field of tissue engineering lately. Recently, triply periodic minimal surfaces (TPMSs) have attracted the attention of tissue engineering scientists for fabrication of biomimetic porous scaffolds. TPMS scaffolds offer several advantages, which include a high surface area to volume ratio, less stress concentration, and increased permeability compared to the traditional lattice structures, thereby aiding in better cell adhesion, migration, and proliferation. In literature, several design methods for TPMS scaffolds have been developed, which considered some of the important tissue-specific requirements, such as porosity, Young's modulus, and pore size. However, only one of the requirements of a tissue engineering scaffold was investigated in these studies, and not all of the requirements were satisfied simultaneously. In this work, we develop a design method for TPMS sheet scaffolds, which is able to satisfy multiple requirements including the porosity, Young's modulus, and pore size, based on a parametric optimization approach. Three TPMSs, namely, the primitive (P), gyroid (G), and diamond (D) surfaces, with cubic symmetry are considered. The versatility of the proposed design method is demonstrated by three different applications, namely, tissue-specific scaffolds, scaffolds for stem cell differentiation, and functionally graded scaffolds with biomimetic functional gradients.