The Experimental Study On The Effect Of Lactic-co-glycolic Acid Stents In Combination With Bone Marrow Mesenchymal Stem Cells In The Repair Of Rabbit Knee Articular Cartilage Defects

BackgroundDegenerative osteoarthritis and autoimmune disease rheumatoid arthritis seriously affect the quality of life of elderly patients due to cartilage lesions;osteochondrosis,osteoarthritis,rheumatoid arthritis,developmental disorders,knee joint infection,bone tumors,sports injuries or other trauma can also cause lack of cartilage.Because the very few blood vessels distribute in cartilage tissue,the regeneration ability of damaged cartilage tissue is relatively poor.At present,no matter clinical drug treatment,conventional surgery or minimally invasive surgery,can not achieve good repair effect.Recently,the development and innovation of tissue engineering technology bring new ideas and methods for the clinical treatment of articular cartilage injury and hope for the rehabilitation of patients with articular cartilage defect.Some studies have found that if BMSCs are attached to the vector and implanted into the where the cartilage defect,the BMSCs will not easily disappear,and can be fixed in the cartilage defect,which is easier to form new cartilage.At present,synthetic bioactive scaffolds are the hotspot in the research of tissue engineering scaffolds.PLGA scaffolds had been used to repair tendon,cartilage and ligament defects.It has been pointed out that PLGA scaffolds not only promote the regeneration of articular cartilage defect,but also have the advantages of strong plasticity,easy absorption and no immune rejection.PLGA scaffolds are more suitable as tissue engineering materials for repairing articular cartilage defect.Tissue engineering technology may improve the treatment of joint injury.Research purposes:To investigate the effect of BMSCs-PLGA on knee cartilage defects repair.Methods:1.Culture and identification of BMSCs: After 3% chloral hydrate anesthesia,bone marrow fluid was taken from tibia of rabbits with 10 ml syringe,BMSCs were cultured and identified by hematoxylin red staining.2.Prepare PLGA scaffolds with a porosity of 92% with a diameter of 4 mm.3.Forty New Zealand rabbits were randomly divided into four groups: control group,PLGA group,PLGA/BMSCs group and BMSCs group.The control group was a cartilage defect model group without any treatment.The PLGA group was treated with full-thickness PLGA scaffolds,the BMSCs group was injected with BMSCs,and the PLGA / BMSCs group was treated with full-thickness PLGA scaffolds adhering to BMSCs.4.At the 8th and 16 th weeks,the new tissues of knee joint defect were observed and stained with HE and toluidine blue.The new tissues of knee joint defect were observed under inverted phase contrast microscopy and scanning electron microscopy.5.The expression of Collagen type II,SOX-9 and Agrecan were quantitatively detected by RT-PCR in the new tissues of knee joint defect of rabbits at the 8th and 16 th weeks.Results:1.There was no inflammatory reaction in knee joints of all groups after operation.At the 8th week,the cartilage defect of PLGA/BMSCs group was filled with pink new bone tissue,the surface of new tissue was hyaline cartilage-like,and the surface of new cartilage tissue was smooth.At 16 weeks after operation,the PLGA/BMSCs group showed that the new tissues in cartilage defect area were bright white,smooth and with no obvious difference in color from the surrounding normal hyaline cartilage.2.At 8 weeks after operation,HE staining showed that the defect area was filled by new tissue in PLGA/BMSCs group.Cellulose-like PLGA scaffolds could be seen in some areas,and PLGA scaffolds were not completely degraded.At 16 weeks after operation,the PLGA/BMSCs group was completely filled with new tissues.Microscopically,the new tissues were dense and arranged columnarly.A large number of cartilage lacunae were observed.The new tissues and surrounding tissues in the defect area were closely combined.No PLGA scaffolds were seen under the microscope,and chondrocytes were found throughout the whole field of vision.3.Scanning electron microscopy showed that the surface of new tissue in PLGA/BMSCs group was smooth,and the pore walls were bridged with each other.The surface of new tissue in injured area was regular,the extracellular matrix was deposited,the compatibility of cells and scaffolds was good,and cell adhesion could be seen on the pore walls.At the 16 th week,scanning electron microscopy of PLGA/BMSCs group showed that PLGA scaffolds were completely decomposed and absorbed,the surface of new tissues was regular,the pore walls were bridged,the deposition of extracellular matrix was more obvious than that at the 8th week,and the cells adhered well to the pore walls.4.The expression of Collagen type II,SOX-9 and Agrecan in PLGA/BMSCs group was significantly increase than that in other three groups by RT-PCR.Conclusion:PLGA scaffold combined with bone marrow mesenchymal stem cells implantation into cartilage defect area is conducive to cartilage regeneration and repair of cartilage defect area of knee joint in rabbits.