Micro-porous PLGA/β-TCP/TPU scaffolds prepared by solvent-based 3D printing for bone tissue engineering purposes

Current 3D printing methods for bone tissue engineering often fail to produce sufficient surface porosity. This limits protein adsorption and cell adhesion, which are important for tissue regeneration. While fused deposition modeling is widely used, it lacks the ability to spontaneously form micropores without additional post-processing. Prior research has shown that solvent-based printing can create micropores during solvent removal. However, no prior work had resolved how to integrate this with osteoconductive materials. The gap motivated the exploration of new scaffold formulations. This study addresses the need for a fabrication method that combines mechanical stability with osteoconductivity. It also seeks to improve the biological performance of 3D-printed scaffolds. The goal is to develop a versatile process for segmental bone reconstruction.

This study aimed to develop and characterize a new scaffold formulation using solvent-based 3D printing. The formulation includes poly(lactic-co-glycolic acid), β-tricalcium phosphate, and thermoplastic polyurethane. The goal was to enhance surface porosity without post-processing. The study also aimed to evaluate mechanical and biological performance. It sought to compare the new scaffolds with commercial calcium phosphate inks. The researchers wanted to assess cell activity and osteogenic differentiation. The objective was to create a scaffold suitable for mandibular bone reconstruction. The study focused on achieving both mechanical stability and osteoconductivity.

The researchers used fused deposition modeling with a solvent-based approach. They formulated scaffolds using poly(lactic-co-glycolic acid) and β-tricalcium phosphate. Some scaffolds also included thermoplastic polyurethane. The printing process allowed spontaneous micropore formation during solvent removal. Scaffold porosity was analyzed using micro-computer tomography and scanning electron microscopy. Nitrogen sorption was used to assess surface area and pore size distribution. Mechanical properties were tested using compression and screw pull-out assays. Biological performance was evaluated with cell activity assays and osteogenic differentiation tests.

The scaffolds demonstrated multiple levels of porosity as confirmed by imaging and sorption analysis. The mechanical properties exceeded those of commercial calcium phosphate inks in compression tests. Screw pull-out tests showed improved mechanical stability. Cell activity assays confirmed cytocompatibility of the scaffolds. Live-dead staining supported the viability of cells on the scaffold surfaces. Osteogenic differentiation was observed in primary human bone marrow mesenchymal stromal cells. The addition of thermoplastic polyurethane enhanced elasticity without compromising porosity. The solvent-based printing method enabled spontaneous micropore formation without extra steps.

The study proposes a versatile fabrication process for 3D-printed scaffolds with enhanced mechanical and biological properties. The solvent-based printing method successfully created micropores without post-processing. The scaffolds showed adequate mechanical stability and osteoconductivity. The researchers demonstrated improved performance compared to commercial calcium phosphate inks. The formulation combining poly(lactic-co-glycolic acid), β-tricalcium phosphate, and thermoplastic polyurethane proved effective. The scaffolds supported cell adhesion and osteogenic differentiation. The findings suggest this approach could be useful for segmental mandibular bone reconstruction. The authors highlight the importance of porosity and mechanical stability in tissue engineering scaffolds.