Experimental Study Of Adipose-derived Stromal Vascular Components Combined With Autologous Granular Cartilage On Rabbit Ear Cartilage Defects

Objective : To combine the adipose-derived stromal vascular component(SVF)with granular cartilage as a cartilage repair material,to explore its effect on the repair of rabbit ear cartilage defects,and to provide experimental basis and treatment for the treatment of clinical cartilage defects.Methods:1.Using tissue separation method to obtain fat from bilateral groin area of New Zealand rabbit,obtain stromal vascular component(SVF)from extracted fat,and label SVF with CM-DiL fluorescent dye,take tissue block specimen of SVF group one month later,Immediately in the dark,the sections were frozen(thickness 5 ?m),observed under a fluorescence microscope at 200 times,and excited by green light at 549 nm,and CM-Dil-labeled SVF(red fluorescence)was observed.2.Establish an animal model of cartilage defects.Five wounds of cartilage full-thickness defect were made in the bilateral auricles of New Zealand rabbits,and the cartilage defects were observed by gross observation and histological observation(HE staining and toluidine blue).3.Preparation of granular cartilage: The cartilage piece obtained was cut into 0.51 x 0.5 cm cartilage pieces by a steel ruler and cut into 1x1 mm size cartilage particles for use.4.Experimental grouping.Twenty-four New Zealand rabbits were randomly divided into five groups with a size of 1.0 x 1.0 cm full-thickness cartilage defects in each New Zealand rabbit's auricle.Group A,blank control group;Group B,granular cartilage group;Group C,SVF group;D,SVF + granular cartilage group;Group E,block cartilage group.Gross and histological observations(HE staining and toluidine blue staining)were performed at 1 month,2 months,and 3 months after surgery.5.Statistical analysis was performed on the specimens of each group at each time period by histological repair scores.Results:1.One month later,the SVF group was taken and the CM-Dil-labeled SVF was observed by fluorescence microscopy,indicating that the SVF-extracted cells contained adipose stem cells.2.Preparation of 1 mm granular cartilage for easy autologous cartilage transplantation.3.Results of observation after transplantation.A.Blank control group: HE staining showed fibrous tissue filling and no neonatal chondrocyte formation.Toluidine blue staining showed no significant metachromaticity to the extracellular matrix.After 4 weeks and 8 weeks of observation,the surface was irregular and there was no normal cartilage formation.12 weeks of cartilage defect scar healing.B.Granular cartilage group: HE staining showed the formation of new chondrocytes,which were found to be surrounded by connective tissue fibers.Toluidine blue staining showed extracellular matrix metaplasia.Gross observation showed that the cartilage particles were partially fused with the normal cartilage tissue at 4 weeks and 8 weeks,and the cartilage defect was shallowed.At 12 weeks,the surface of the cartilage defect was not flat,the cartilage defect was basically repaired,and the cartilage particles were fused into a piece to show cartilage formation.C.SVF group: HE,staining can be seen in the formation of new chondrocytes.Toluidine blue staining showed that the matrix was metachromatic.In general observation,there is a membrane formation in the defect area,and a large number of new chondrocytes are formed,which has a certain repairing effect on the defect.D.Granular cartilage group + SVF group: HE staining showed a large amount of neonatal chondrocyte formation around the granular cartilage.Toluidine blue staining showed that the matrix was metachromatic.The general observation surface is smoother,close to the surrounding normal cartilage thickness,and can be completely fused with normal cartilage.E.Bulk cartilage transplantation: HE staining showed the formation of neonatal chondrocytes around the massive cartilage,and the extracellular matrix was slightly reduced.The general observation surface is smoother,close to the normal cartilage thickness,and merges with the surrounding cartilage.However,a small part of the transplant has warpage.Conclusion:1.Adipose-derived SVF combined with granular cartilage can effectively repair rabbit ear cartilage defects.2.After preparation into granular cartilage,it is beneficial to the regeneration of cartilage and the repair of cartilage defects.After the transplantation of granular cartilage,it can be well fused with the surrounding tissue and form a whole,without obvious absorption,and the cartilage activity and ossification are relatively stable.3.SVF can promote the regeneration of cartilage.