Long-Term in Vivo Performance of Low-Temperature 3D-Printed Bioceramics in an Equine Model.

The researchers found that brushite-based implants derived from 3D printing technology can effectively promote bone regeneration in large animal models, specifically horses. The study also revealed that these implants were able to degrade and be replaced by new bone formation after a period of 6 months, showcasing their potential for treating critical sized bone defects.

Introduction

• This study delved into the potential of brushite, a type of calcium phosphate, as an ideal material for bone replacement due to its solubility and consequent ability to promote bone regeneration.
• The researchers produced these brushite-based materials using 3D printing technology, which could be customized according to the needs of the animal.
• The in vivo test involved implanting these 3D-printed scaffolds in the horse model and monitoring them over a span of 6 months. The process was relatively simple and did not lead to discomfort in the animals.

Methodology

• The researchers began by characterizing the properties of the brushite-based scaffold.
• Next, they implanted these 3D-printed materials in the equine tuber coxae, an upper part of a horse’s hip, and allowed them to settle for over 6 months.
• The in vitro tests were aimed at determining the strength of the material. They revealed that the densely printed material possessed a compressive strength of around 13 MPa, which decreased to approximately 8 MPa in the porous implant design.

Results and Conclusion

• Findings revealed that roughly 40% of the implants’ visible volume was degraded and replaced by bone after 6 months, demonstrating the materials’ ability to promote new bone growth.
• Upon histological analysis, researchers noted substantial bone ingrowth. Comparatively, defects that were left empty were filled only with fibrous tissue, further confirming the osteoconductive capacity of the 3D-printed brushite implants.
• The study confirmed the potential of 3D-printed brushite implants to stimulate new bone growth after a 6-month implantation in a large animal model. The researchers also suggested that the equine tuber coxae bone model could be effectively used for future bone regeneration studies.