| Objective:Articular cartilage injury is a common and frequently occurring disease in clinic.The disease can cause joint pain and joint mobility disorders,and even affect the patient’s work and life in severe cases.At present,there are various methods for the treatment of articular cartilage injury,but the curative effect is not satisfactory.How to repair articular cartilage injury has become a hot topic of scientific research.In recent years,Bone marrow mesenchymal stem cells(BMSCs)and Platelet-rich plasma(PRP)have been reported to be responding well to the treatment of articular cartilage injuries,but the mechanism of action is not fully understood.Therefore,attempts were made to coordinate,help and promote related cells to differentiate into chondrocytes from articular cartilage injury or promote chondrocyte regeneration under the condition of artificially controlling the related variables,so as to accelerate the repair of articular cartilage injury area,so as to clarify the mechanism of action of the two to promote articular cartilage repair,in order to provide some references for future medical or scientific research workers.Methods:In this study,36 6-month-old healthy rabbits were randomly divided into 4groups: Group A(microfracture +BMSCs),group B(BMSCs injection alone),group C(PRP injection alone)and group D(blank control group),with 9 rabbits in each group.(2)Reagents:HE staining section related reagents,immunohistochemical related reagents.(3)Surgical methods:(1)Cartilage defect model: The full-layer articular cartilage defect of about 6mm×6mm was prepared on the weight-bearing surface of the medial femoral condyle joint of the right knee joint of rabbit;(2)Microfracture: A "microfracture" model was established with a special bone knife on the cartilage defect surface.The hole depth was 4mm and the hole distance was about 3.0mm-4.0mm.(3)About 0.5ml bone marrow fluid was pumped with a20 ml syringe into the knee joint of the operative side of microfracture,once a week,three times in total;(4)PRP was extracted by centrifuge and injected into the damaged area of cartilage about 0.5ml each time,once a week,three times in total.(4)Analysis of the experimental effect:(1)General observation: The animals were sacrificed 7,14 and 21 days after surgery,and pathological changes in the articular surface defect area of medial femoral condyle were observed.(2)Preparation of sections: After general observation,some tissues were fixed with 10% formaldehyde,decalcified with 30% formic acid,embedded in paraffin,and prepared into 4μm sections for use.(3)Routine HE staining with light microscopy:histological examination,HE staining,and histological analysis of cartilage repair.(4)Immunohistochemical observation: The sections prepared by the above methods were observed by immunohistochemical rendering.By detecting the proportion of positive cell expression area of BMP-2 and TGF-β 3,the effect of intraarticular injection on cartilage regeneration and repair of articular cartilage injury was analyzed.Results:(1)The cartilage defect area of group A,B and C was obviously covered by new cartilage,and the defect area of group D was still clearly visible,showing the worst repair effect.The repair effect of group A>B>C>D was compared according to the articular surface score.(2)Under the electron microscope,A large number of new chondrocytes and new bone tissue could be seen in the cartilage defect area of group A and B.Under the microscope,the number of new chondrocytes and bone tissue in group A was more than that in group B.As time went by,the number of new chondrocytes and new bone increased.Compared with the first two groups,the number of new chondrocytes and bone tissue in group C was relatively small,but the number of chondrocytes gradually increased with the passage of time.In group D,a small number of chondrocytes were found in the defect area,and few new chondrocytes and bone tissue were found.(3)After immunohistochemical rendering,protein factor expression in groups A,B and C gradually increased with the passage of time,and the proportion of positive cell expression area gradually increased.The positive expression rate of groups A,B and C was compared with that of group D at the time points of 7d,14 d and 21 d by statistical analysis.P<0.05 was found in each group,and the difference was statistically significant.The expression proportion of each group was ranked as A>B>C>D from high to low.Conclusion:(1)In the repair of rabbit articular cartilage injury,the effect of microfracture combined with intra articular injection of BMSCs was more obvious than that of intra articular injection of BMSCs alone;(2)Proper injection of BMSCs and PRP in the articular cavity within a certain period can promote the repair of rabbit articular cartilage injury;(3)PRP can promote the repair of rabbit articular cartilage injury,but the effect of single application is not good,and the time may be long;(4)BMSCs injected into the knee cavity of rabbits in a certain period has a better repair effect on cartilage injury than PRP. |
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