A control approach for pore size distribution in the bone scaffold based on the hexahedral mesh refinement

Tissue engineering is the application of that knowledge to the building or repairing of tissues. Generally, engineered tissue is a combination of living cells and a support structure called scaffolds. Modeling, design and fabrication of tissue scaffold with intricate architecture, porosity and pore size for desired tissue properties presents a challenge in tissue engineering. In this paper, a control approach for pore size distribution in the bone scaffold based on the hexahedral mesh refinement is presented. Firstly, the bone scaffold modeling approach based on the shape function in the finite element method is provided. The resulting various macroporous morphologies can be obtained. Then conformal refinement algorithm for all-hexahedral element mesh is illustrated. Finally, a modeling approach for constructing tissue engineering (TE) bone scaffold with defined pore size distribution is presented. Before the conformal refinement of all-hexahedral element mesh, a 3D mesh with various hexahedral elements must be provided. If all the pores in the bone scaffold need to be reduced, that means that the whole hexahedral mesh needs to be refined. Then the solid entity can be re-divided with altered subdivision parameters. If the pores in the local regions of bone need to be reduced, that means that 3D hexahedral mesh in the local regions needs to be refined. Based on SEM images, the pore size distribution in the normal bone can be obtained. Then, according to the conformal refinement of all-hexahedral element meshes, defined hexahedral size distribution can be gained, which leads to generate defined pore size distribution in the bone scaffold, for the pore morphology and size are controlled by various subdivided hexahedral elements. Compared to other methods such as varying processing parameters in supercritical fluid processing and multi-interior architecture design, the method proposed in this paper enjoys easy-controllability and higher accuracy.