The Research Of Computer-aided Design And Manufacture Individual Bone Defect Scaffold

Objective:To combine with new technologies, such as tissue engineering(TE), computer aided design (CAD),rapidprototyping(RP), reverse engineering(RE), finite element analysis(FEA), to design and manufacture individual bone defect scaffold. The purpose of this research is for separating and culturing the bone marrow stromal cells from Beagle dog, and induce differentiate to into the osteoblast. Individual bone defect scaffolds are designed and manufactured by using computer aided design and rapid prototyping. To constructe the tissue engineering bone scaffold in vitro with osteoblast and individual bone defectβ-tricalcium phosphate,β-TCP) ceramic scaffold. Using the finite element method to analysy the stress value in difference ways of fixationg with individual bone defect scaffold for reconstructing bone defect, and computer-aided design individual bone defect scaffold to repair tumor bone defect,to provid mechanics parameter in bone defect reconstruction.Method:1. The Beagle dogs'bone marrow stromal cells are separated in the method of the density gradient centrifuge process and pastes wall cell separation law unifies. And The bone marrow stromal cells was cultured, amplificated, and biological characteristics of bone marrow stromal cells was also appraised.2. The bone marrow stromal cells are induced differentiate to into the osteoblast using ascorbic acid,β-sodium glycerophosphate, dexamethasone and 10%FBS/DMEM. The evaluation of morphology, histochemistry, immunity dyeing of the cells after inducing are carried on.3. The bone tissue engineering scaffolds with different basic internal architecture units are designed using computer-aided design. And the stress and total deformity in the basic architecture units are tested in the ways of finite element analysis. After that the bone tissue engineering scaffolds with precise pore size, porosity, connectivity are designed using computer aided design.4. The photoallergy resin of minor and exterior die of bone tissue engineering scaffolds are manufactured using stereo lithography apparatus. After that theβ-TCP ceramic slurry perfuse into the minor die of bone tissue engineering scaffolds, The bone tissue engineering scaffolds with precise pore size, porosity, connectivity,are manufactured using in-situ consolidation and high sintering.5. To construct bone tissue engineering scaffolds with with osteoblast and individual bone defectβ-TCP ceramic scaffold in vitro, surveyed the capability adhere and proliferation of osteoblast after cultured in 7 days.6. The tibial bone defet module is built by computer-aided technologies, and the module of individual bone defect scaffolds matching with the profile of bone defect are designed by computer aided design. The module of bone defect reconstruction with golf plate and intramedullary pin fixation are installed by computer aided design. The value of the stress in different fixation of bone defect reconstruction are measured by finite element analysis.7. The proximal tibia bone tumor module is built by computer-aided technologies,and measure the range of the tumor bouncary, design the plane of tumor resection. The computer-aided design technologies are used to design individual bone defect scaffold,build the 3D module of golf plate fix bone defect. The value of the stress and strain in proximal tibia bone tumor reconstruction with golf plate and individual bone defect scaffold are measured by finite element analysis.Results:1. The bone marrow stromal cells harvest in the method of the density gradient centrifuge process and pastes wall cell separation law unifies. The BMSCs showed long fusiform shape and spread orderly along a direction, had a 90% fusion after cultured 14 days, The form and multiplication characteristic of the BMSCs has not changed after transfer of culture 3 times. The P2 BMSCs has 74.38% in Gl stage,0.4% was in G2 stage, and 25.23% was in S stage. The characterization of BMSCs histochemistry dyeing results showed that the glucogen PAS(+),oil red "0" (－).AKP(－).2. The cells inducted and cultured from BMSCs in 14 days, shows polygon and turn bigger and circler with osteoblast induction nutrient solution,which contain ascorbic acid,β-sodium glycerophosphate, dexamethasone and 10% FBS, DMEM. The characterization of cells histochemistry dyeing results showed that AKP(+), alizarin Bordeaux(+), VON KOSSA(+),I style collagen immunity dyeing(+), The results prove the cells is osteoblast.3. We finished successful the different basic internal architecture units which designed using computer-aided design technologies. The results of the FEA showed that the value of the stress and total deformity has the lowest in open cube unit, cube-cast unit is the second, and cube-spheroplast unit is the worst. We can design the the bone tissue engineering scaffolds with precise pore size, porosity, connectivity and the minor module of the scaffold using computer aided design software.4. The photoallergy resin of minor die of bone tissue engineering scaffolds can be manufacture using rapid prototyping technologies. Theβ-TCP ceramic scaffold with pore size, porosity, connectivity,can be manufactured precisely using in-situ consolidation and rapid prototyping technologies.5. The osteoblast proliferate and adhere very well in the porosityβ-TCP ceramic scaffold after 7 days culture in vitro. The HE dyeing result showed that all of the scaffold conduit wall have osteoblast proliferation and adherent.6. The 3D module of bone defect reconstruction with golf plate and individual bone defect scaffold, intramedullary pin and individual bone defect scaffold were built using computer-aided design technologies. And the finite element module was also built in the FEA software. The value of stress in module of bone defect reconstruction with golf plate and individual bone defect scaffold is 24.37 Mpa, intramedullary pin and individual bone defect scaffold is 13.51Mpa. The intramedullary pin fixation is a good choice for bone defect reconstruction in shaft of tibia.7. With the help of computer aided design and reverse engineering software, We designed successful individual bone defect scaffold matching with the profile of bone defect. In the finite element analysis axial direction pressurize test, the maximum value of stress is 18.26Mpa. In torsion test, the maximum value of stress is 64.466Mpa. The ways of golf plate and individual bone defect scaffold to reconstruct the proximal tibia bone tumor bone defect can provide a enough mechanics stabilize. Conclusion:1. Bone marrow stromal cells is an ideal seed cell for bone tissue engineering.2. The bone tissue engineering scaffolds with different internal architecture are designed using computer-aided design technologies.3. Theβ-TCP ceramic scaffold with precise pore size, porosity, connectivity, can be manufactured using computer aided design and rapid prototyping technologies.4. Theβ-TCP ceramic scaffold is of well biocompatibility.5. Individual bone defect scaffold matching with the profile of bone defect can be designed by computer aided design and reverse engineering technologies.6. Finite element analysis is a good method for providing mechanics parameter in bone defect reconstruction.