Evaluation of Mechanobiological Potential of 3D-Printed PLA Bone Tissue Scaffolds with Different Pore Architectures and Porosity Ratios

Abstract

Lattice structures are widely used in bone tissue scaffold designs due to interconnected porous structures that mimic the natural extracellular matrix (ECM) to treat large bone defects. Moreover, bone regeneration is a mechanobiological phenomenon that can be affected by mechanical stimulation. This study investigated the mechanical behavior of bone tissue scaffolds with different pore architectures and porosity ratios using experimental and numerical methods. In addition, mechanobiological potentials of scaffolds were evaluated in terms of the specific energy absorption and the specific surface area. Basic Cube (BC), Body-Centered Structure (BCS), and Body-Centered Cubic (BCC) structures were chosen as pore architectures for scaffolds with 50%, 62.5%, and 75% porosity ratios. Scaffolds were printed with PLA filament using an FDM printer. Compression tests were performed to calculate stiffness values and energy absorptions of the scaffolds. Finite element simulations were used to obtain stiffness values of scaffolds. The specific energy absorptions of scaffolds were calculated under 4 N compressive load as a representative of potential body loads. According to the results, it was found that pore architectures and porosity ratios had crucial effects on stiffness values, energy absorption levels, specific energy absorption, and specific surface area which may lead significant differences in bone remodeling. The highest specific energy absorption was observed in the BCS75 scaffold, while the highest specific surface area was observed in the BCC75 scaffold.