Bone Regeneration Using Immature-Osteoblasts and Three Dimensional Polymer Scaffolds With Functional Properties Like Native Bone

Objectives: The aim of this study was to develop a technology for bone tissue engineering by evaluating the bone regenerative efficacy of mouse calvaria–derived immature osteoblast–like cells (MCOB) in combination with a three-dimensional polylactic acid scaffold (3DPL) in large jawbone defects of mice
Methods: MCOB were isolated from mouse calvaria and confirmed their osteogenic characteristic properties. MCOB-3DPL constructs were prepared by static seeding of MCOB onto sterilized 3DPL scaffold. A large maxillary jaw bone defect model was prepared in a BL6 mic. The defects were implanted with either MCOB-3DPL constructs or 3DPL scaffold without cells, or commercial bone graft material (cytrans) or left unfilled (empty defects). New bone regeneration ability in the defect site was investigated by histological and micro-CT analysis. In addition, the biomechanical properties of the regenerated bone were evaluated by nanoindentation testing and implant therapy.
Results: The results of Micro CT and histological analysis demonstrated that implanted MCOB-3DPL constructs have successfully regenerated bone within bone defects and is significantly higher than the other groups at 8 weeks post-implantation. Nanoindentation analysis has shown that regenerated bone induced by MCOB-3DPL constructs has micromechanical properties comparable to the native bone. Furthermore, histological analysis after implant therapy revealed that the regenerated bone formed by the MCOB-3DPL constructs has the ability to osseointegrate, establishing a direct structural connection with the implant surface.
Conclusions: Tissue constructs prepared from 3DPL scaffold and immature osteoblast-like cells such as MCOBs could serve as new bone tissue engineering technique that enables new bone formation along with the micromechanical properties comparable to native bone. Regenerated bone possess osseointegration ability which could be used for implant therapy and indicating that it is suitable for regeneration of bone in the oral and maxillofacial large bone defects in humans.