Biological and mechanical property analysis for designed heterogeneous porous scaffolds based on the refined TPMS

For tissue engineering (TE), triply periodic minimal surfaces (TPMSs) have received widespread application, as they produce smooth surfaces and pore interconnectivity, which can satisfy the biological/mechanical requirements and efficiently construct many complex bone scaffolds. To control the microstructure of the scaffold and mimic the anisotropy of native tissue, a design approach for heterogeneous porous scaffolds is proposed in this paper. It is carried out by discretizing the original model using the conformal refinement of an all-hexahedral mesh and mapping the TPMS units to the mesh elements with the help of a shape function. Another aim of this work is to assess the impact on the biologic/mechanical properties of the model, as it is discretized with different mesh patterns. It is found that the mesh pattern has a non-obvious effect on the surface curvature distribution that is a crucial factor to osteoblast proliferation in the TPMS scaffold. Nevertheless, the comparison presents that the mechanical properties of the refined scaffolds model exhibited anisotropy and improvements in elasticity, strengths, and especially energy absorption. With the help of conformal remeshing, the local density of architecture can be conveniently controlled and the elastic modulus of scaffold can be designed to the appropriate range in a specified area in order to mimic the actual cancellous bone.