Mechanical Characterisation of 3D-Printed Porous PLA Scaffolds with Complex Microarchitectures for Bone Tissue Engineering Applications

Abstract

Bone transplantation remains the leading approach in addressing orthopaedic trauma or disease. In cases where this option is not viable, bone tissue engineering offers an alternative through the use of scaffolding. This approach involves the removal of damaged bone tissue and its replacement with porous scaffold structures to support the regeneration process. Recently, additive manufacturing has emerged as a promising technology for producing scaffold structures that satisfy the necessary performance criteria. In this study, PLA scaffolds with tortuous pore network designs were fabricated using fused deposition modelling. Scaffolds were fabricated with four different porosity values by changing the pore diameter in the range of 840–1732 µm. Sixteen specimens were tested under monotonic compression testing. Result shows the elastic moduli generated by each sample with 25%, 45%, 60% and 75% porosity: 545.21 ± 109.76, 446.82 ± 57.12, 312.55 ± 82.64 and 123.81 ± 23.95 MPa, respectively. Finite element simulation showed good correlation with experimental results, thereby effectively assessing the scaffold mechanical behaviour. Accordingly, the proposed finite element model can predict the mechanical behaviour of fabricated bone scaffolds accurately. The results demonstrate that the numerically predicted elastic modulus of complex scaffold is not closer to experimental outcomes in comparison with as-built samples. Overall, these findings suggest the potential of 3D-printed PLA scaffolds with tuneable porosity for cancellous bone replacement applications.