The Research On Using Computer-aided Tissue Engineering To Precisely Repair Osteochondral Lesions

Objective:Combined with new technologies,such as tissue engineering(TE),reverse engineering(RE),computer-aided design(CAD),rapid prototyping(RP), supercritical C0₂ fluid extraction(SFE-C0₂),et al.using computer-aided to analyse the scope of osteochondral lesions,using CAD to design how to excise the lesion region;to study how to custom the osteochondral composite tissue which's shape is matched with the excisional region of osteochondral lesions and how to closely implant it in vivo by computer-aided tissue engineering (CATE).Provide a new method to accurately repair osteochondral lesions.Method:1.Collect 20 patients of osteonecrosis of the femoral head who were cured by the total hip arthroplasty in clinic,obtain the 2-D image of preoperative hips' CT and MRI,according to computer-assisted three-dimensional reconstruction accurately calculate the volumes of femoral head and zone of necrosis,contrast with the postoperative specimen.2.In vitro separate rabbit articular cartilage,isolated culture primary chondrocyte by enzyme digestion,and identify it by morphology and histology.3.Articular chondrocyte as the seed cell,fibrin gel as the scaffold.rabbit articular chondrocytes after expansion by in vitro culture in different densities of cell suspension were grafted on the scaffold material,to carry out experiments in vitro and investigate the appropriate selection of cell density.4.In vitro separate rabbit tibial periosteum,by means of pieces enzyme digestion in batches to isolate and culture the primary osteoblasts,and identify it by morphology and histology.5.By means of CAD design and selective laser melting direct rapid prototyping, to preparate the surgical instruments and template.6.Using the techniques of computer-assisted and SFE-C0₂ to prepare the personalized implant of osteochondral scaffold.7.Beagle as the experimental animal,computer-assisted excise the osteochondral tissue of femoral head central 1/3 accurately,and implant the matched osteochondral composite tissue,to observe osteochondral tissue regeneration and repairation process.Results:1.Using of the computer three-dimensional reconstruction to deal with CT images of femoral head can accurately calculate the size of the femoral head; Using of the three-dimensional reconstruction to deal with MR images of osteonecrosis region of the femoral head can accurately calculate the volume of necrotic region;the measurement results are close to the specimens obtained by operation.2.The primary chondrocytes harvested by enzymatic digestion access to spherical,cultured cells from 2 to 5 days in a logarithmic phase,eytoactive were maintained at 90%in 7days;HE staining,toluidine blue,â…¡-type collagen immunohistochemical staining and transmission electron microscopy were seen of the performance characteristics of chondrocytes.3.Fibrin gel scaffold composites with cells easily,100%of cells was added to our catalog;through general observation,HE staining,andâ…¡collagen immunohistochemical staining,think that the 5×10⁷/ml is the best density of seed cells for inoculating to the fibrin gel.4.The primary periosteal osteoblasts harvested by pieces enzyme digestion in batches is easier than traditional methods,the cytoactive of cultured osteoblast is better;HE staining,transmission electron microscopy and AKP staining were showed the characteristic of osteoblasts.5.The personalized surgical template prepared by CAD and RP can be used on operation for aiding and making the osteochondral defect model of the central 1/3 of femoral head precisely;The implantation cutting template prepared by CAD and RP can be used for aiding and making allograft bone scaffold matched with the model of osteochondral defect. 6.Allograft bone scaffold made by computer-assisted is matched with the designed model of bone defect.Supercritical C0₂ fluid extraction and 30%H₂0₂ can remove the main antigen of allograft bone-lipoprotein,after a series of observation like as scanning electron microscope,show that the internal morphological structure of treated allograft bone is suitable for preparing tissue engineering bone scaffold of weight-bearing region.7.Matchedly and tightly implanting the osteoblasts-scaffold composite and chondrocytes-fibrin gel composite into osteochondral defect region as mosaic in vivo,can promote the process of osteochondral tissue regeneration and repairation.Conclusion:1.The use of tissue engineering technology can prepare a novel,efficient and"live"material for repairing tissue-osteochondral composite tissue.2.Computer-aided tissue engineering technology is a novel approach,which's design is precise,can accurately preparate the osteochondral composite tissue matched with the removal of osteochondral lesions profile,and can matchedly implant it in vivo.it provides a new method for precisely repairing the osteochondral lesion.