Three Dimensional Reconstruction Model Of Mice Vertebrae And Study Of Bionic Vertebrae

Bionic vertebrae can provide individualized repair and replaceable function for vertebral defect.How to imitate the highly irregular vertebrae morphology and optimize the preparation materials of the vertebra like vertebrae has always been a problem to be discussed in depth.In this study,a real mice vertebra is used as a prototype,through the three-dimensional reconstruction and 3D printing technique,to construct an individualized vertebra model.And the further optimization of the bionic vertebrae is discussed by constructing a co-culture system of the cell-free decalcified bone matrix of vertebra and the seed cell.Firstly,the morphology of the vertebrae of the ICR mice is observed by anatomic observation.In this experiment,the vertebrae of mice are composed of seven cervical vertebrae,thirteen thoracic vertebrae,six lumbar vertebrae and twenty-seven caudal vertebrae,all of which are irregular bones.We select the second lumbar(L2)vertebrae of the mice and analyze its constitutes by paraffin embedding,continuous tissue slicing and HE staining.L2 vertebrae contains several special structures including transverse process,transverse foramen,spinous process and vertebral body.Four hundred and thirteen pieces of continuous tissue slices obtained in the first step are microphotographed,and the images are spliced,grayscale processed,and then matched by Photoshop CS6 and Image Pro Plus.And we reconstruct the 3D structure of the vertebrae using 3D-Doctor software.Data analysis shows that the model volume is 3.6 mm~3 and the surface area is 138.8 mm~2.The length,width,and height of the model are 5.3 mm,4.7 mm and 3.7 mm,respectively.The measured size is close to the original vertebral size.In the end,the reconstructed physical model of the vertebrae is printed with a 3D printer,using PLA or ABS as printing material.We find that PLA is more suitable as the material for the real vertebra.Further study of the class-like vertebrae model contains cells.The 2rd-4th lumbar vertebrae are decellularized and decalcificated,and the vertebral scaffold inoculats with osteoblast-like cells for co-culture.The osteoblast-like cells are the bone marrow mesenchymal stem cells(BMSCs),which are extracted from the femur and tibia of ICR mice for subculture and osteogenic differentiation,and then inoculated to vertebral scaffold.The results show that the cell-free decalcified bone matrix has no cytotoxicity to BMSCs and do not affect the cell morphology,proliferation and differentiation ability.Meanwhile,we observe that the 3D porous structure of the scaffolds is suitable for the cell-cell interactions,and cells can adhere to scaffolds well.Through the exploration of this topic,we have obtained a three-dimensional reconstruction and 3D printing method of the vertebral individualized model,and proved that the cell-free decalcified bone matrix can be used as a scaffold for the bionic vertebrae.The results of this study provide a technical route for the model reconstruction of the bionic vertebrae,and lay the foundation for good scaffold materials.