Three-dimensional printed tissue engineered bone for canine mandibular defects.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Oral and Maxillofacial Surgery

Background:

• Tissue engineered bone, fabricated using 3D printing, was investigated for repairing bone defects in the oral and maxillofacial (OMF) region.
• Experimental dogs served as the model for evaluating the efficacy of these engineered bone constructs.

Purpose of the Study:

• To assess the feasibility of using 3D printed nanoporous hydroxyapatite scaffolds for OMF bone defect repair.
• To determine the optimal in vitro co-culture time of canine bone marrow stromal cells (BMSCs) with the scaffolds for in vivo bone regeneration.

Main Methods:

• Canine BMSCs were cultured and induced for osteogenic differentiation.
• A 3D surgical guide and mold were fabricated using a high-precision printer and implant materials, followed by high-temperature sintering.
• Tissue engineered bone constructs were co-cultured with BMSCs for 2 or 8 days before implantation into bone defects in dogs.
• Postoperative CT and micro-CT scans were utilized to evaluate osteogenesis and material degradation.

Main Results:

• Nanoporous hydroxyapatite implants with a porous structure and hard texture were successfully fabricated.
• BMSCs with osteogenic induction adhered densely to the scaffold surface, secreting extracellular matrix (ECM) and forming calcium-like crystal nodules.
• No significant difference in in vivo osteogenesis was observed between constructs co-cultured for 2 days versus 8 days.

Conclusions:

• 3D printed nanoporous hydroxyapatite scaffolds, produced via high-temperature sintering, effectively repair in situ bone defects in experimental dogs.
• The co-culture time for tissue engineered bone can be reduced from 8 days to 2 days without compromising in vivo osteogenic effects.