Fabrication and Characterization of Porosity-Gradient Poly lactic Acid/Bredigite Composite Scaffolds via Fused Deposition Modeling for Bone Tissue Engineering

Abstract

Despite extensive research on three-dimensional (3D)-printed scaffolds for bone tissue engineering, constructs capable of accurate replication of bone structure have remained a significant challenge. This study, aims to develop porosity-gradient scaffolds based on poly lactic acid (PLA)/Bredigite (Ca7MgSi4O16) nanoparticles using the fused deposition modeling (FDM) technology to simulate the two distinct cortical and cancellous layers of the natural bone with 3-D interconnectivity to promote richer supply of blood, oxygen, and nutrients for healthy in-growth of bone cells and supporting mechanical properties necessary for tissue growth. The role of Bre nanoparticles and porosity gradient on the mechanical, physiological, and biological properties of scaffolds was also addressed. The results showed a significant improvement in the compressive strength of the scaffolds with porosity gradient compared to scaffolds without gradient (i.e. compressive strength of 172 ± 32.2 MPa for PLA/20% Bre scaffold vs. 40.2 ± 24 MPa for the pure polymer scaffold). The scaffolds with porosity gradient and Bre nanoparticles significantly improved the in vitro bioactivity of scaffolds, proliferation, osteogenic differentiation of osteoblast-like cells, and mechanical properties, making them attractive for bone regeneration. In summary, the PLA/Bre scaffolds with porosity gradient can be an appropriate candidate for bone tissue engineering.