Characterization of 3D-Printed B-TCP Scaffolds with Enhanced Microstructure, Mechanical Properties, and Cell Compatibility

Achieving bone regeneration in large defects caused by trauma, pathology and atrophy is a challenge. Innovative implant materials are emerging as alternatives to autografts in regenerative medicine. 3D-printed B-tricalcium phosphate (B-TCP) scaffolds have emerged as a promising solution for bone tissue replacement, offering patient-specific implants without relying on donors or transplantation. There are many open questions that need to be addressed before they can be used on a large scale. The analysis of sintering temperatures and the different crystalline phases, the in-depth evaluation of the microstructure and its biological response, as well as the assessment of suitable mechanical properties are some of these. The present study carried out a comprehensive characterization of the microstructure of commercial 3D-printed B-TCP using X-ray diffraction coupled with Rietveld refinement, X-ray microtomography and scanning electron microscopy. In addition, blood and cell compatibility tests were carried out using MG63 cells. The imaging techniques revealed the influence of the sintering treatment on the microstructure, resulting in an increase in the average pore size, efficient coalescence between particles and a shrinkage effect at higher temperatures. This behavior had a direct impact on the mechanical properties and cell adhesion behavior. Blood compatibility showed no significant differences between all the samples. However, the material sintered at 1200 °C showed better mechanical properties and a better behavior in the adhesion and proliferation of MG63, which were correlated with a higher density, improved mechanical properties and interconnected porosity, which play a key role in improving osteoblastic function.