Parametric evaluation of 3D-printed polylactic acid scaffolds: Balancing mechanical and biological performance for bone tissue engineering

This study presents a novel approach to evaluating how individual design parameters affect the mechanical and biological performance of 3D-printed polylactic acid cylindrical bone tissue scaffolds. By systematically varying one parameter at a time (strand thickness, pore size, porosity, or orientation), their individual impacts are precisely assessed. Mechanical properties are incorporated into finite element analysis simulations that mimic femoral loading conditions. Results indicate that scaffolds with a 45 degrees orientation and the smallest strand thickness exhibit the highest deformation, while those with a 60 degrees orientation and the thickest strands show the lowest deformation. Moreover, the highest stress was observed in geometries with 45 degrees orientation, and those with 90 degrees had the lowest stress levels. These results suggest that geometries with 60 degrees and 90 degrees angle provide the sturdiest constructs for load bearing applications in bone tissue engineering. These findings are validated through experimental compression tests. Among the 36 proposed geometries, seven scaffolds display equivalent stress values within the acceptable range for cortical bone compressive strength. The optimized designs align mechanical properties with natural bone, potentially mitigating issues like osteopenia and stress shielding associated with stiffer implants. Contrary to prior recommendations for high porosity (>70%), proposed designs with 40-57% porosity can satisfy both mechanical and biological requirements, suggesting that lower-porosity scaffolds can achieve cellular proliferation rates comparable to those with higher porosity, as supported by existing studies. Future research will include biological tests to validate the biocompatibility of these optimized scaffolds.