Geometrical analysis of extrusion based (Additively Manufactured) 3D designed scaffold for bone tissue Engineering: A finite element approach

Abstract

The gap between demand and supply for the required bone graft and donor is widening day by day. Tissue engineering approach is used to overcome the limitations of bone graft substitutes. In Tissue Engineering, a biocompatible scaffold is placed inside the body, which over a period of time gets converted into the bone Extra-Cellular Matrix (ECM). Hydroxyapatite (HA) and β-Tricalcium Phosphate (β-TCP) are extensively studied to fabricate bone scaffolds for tissue engineering applications by conventional methods. However, the scaffold needs to be produced with controlled pore size, porosity, and pore interconnectivity for homing of the cells which can be achieved by additive manufacturing. Also, the scaffolds produced with conventional methods lack mechanical properties which limit the use of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) at the recipient site. In this paper, scaffolds with different materials' compositions, different layers orientations, and pore sizes are designed as an input parameter for different scaffold architecture which has not been previously studied considering extrusion-based additive manufacturing. These parameters are considered to predict the mechanical properties of the scaffold architecture. It has been found that in all combinations the scaffold with 0°- 90°- 0°- 90° orientation layer gives Young’s modulus that is comparable to natural human bone. However, the scaffolds with 0°- 90° -0°- 90° orientation layer and 350 µm pore size gives comparatively higher effective Young’s modulus of about 30.948 GPa for 5% HA composition. In the future 0°- 90°- 0°- 90° orientation can be considered to fabricate 3D scaffold architecture using extrusion-based additive manufacturing method.