In Vivo Study on Bone Response to 3D-Printed Constructs Designed from Microtomographic Images

The design of scaffolds that could adjust and adapt greatly to bone defects is a significant challenge to bone tissue engineering. Recently, 3D printing technology emerged as a process that could precisely control the architecture and design an exact geometry of the scaffold to the site or defect where it will be implanted. Thus, this research aimed to design and synthesize individualized constructs of polylactic acid (PLA) by 3D printing using microtomographic images to fit the edge of Wistar rat calvaria's critical size defects. The 3D-printed construct using the DICOM data of microtomographic images process to STL manipulated and designed by various software showed an excellent geometry. The in vitro biocompatibility assay of the 3D printing scaffold was evaluated by WST-1, showing an excellent biological response. Moreover, the in vivo evaluation of the bone regeneration process onto the rat calvaria defect model measured by the bone mineral density (BMD) at 8, 30, 60, and 90 days via micro-CT showed that at the end of the evaluation period, the 3D construct was integrated into the edges of the bone tissue, and new tissue deposited was in the process of mineralization. These findings suggest that the 3D construct matches the calvaria defect, allowing the novo mineral tissue to form. These individualized printed scaffolds may be a promising candidate in bone tissue engineering for future regeneration strategies.