| Background:Osteoarthritis(OA)is a chronic arthritis in which the balance of articular chondrocytes and extracellular matrix is destroyed,resulting in cartilage damage.Its morbidity is second only to cardiovascular disease,and with the increase of age,people over 70 years old can reach 80%,and the disability rate can reach 53%,causing huge economic losses to the society and families [1].Currently,there is no ideal drug that can effectively prevent further injury of OA cartilage or restore joint function.The self-repair ability of articular cartilage after injury is limited.In recent years,it has been found that stem cell transplantation can promote cartilage repair,which has become a research hotspot in OA treatment.Osteoarthritis in addition to the biological mechanics and mechanical damage,study that local inflammation of the joints factor is cartilage damage,extracellular matrix degradation,important pathological mechanism to promote the development of osteoarthritis last [2-5],these inflammatory factors at the same time can promote the downstream mediators of inflammation such as matrix metalloproteinases,nitric oxide,prostaglandins,amplifying the inflammatory response and accelerate OA articular damage [6].Mesenchymal stem cells can secrete a variety of cytokines and growth factors,and these bioactive factors have nutritional effects,can inhibit the local immune system,inhibit the formation of scar and cell apoptosis,control intra-articular inflammation,and provide a more ideal new method of stem cell therapy for osteoarthritis.Objective:To evaluate the feasibility of the rat osteoarthritis model by injecting papain into the articular cavity,and to extract the dental pulp mesenchymal stem cells for the treatment of osteoarthritis,and to investigate the effect of the cells on il-1 and TNF in the synovial fluid.Methods:(1)The pulp mesenchymal stem cells were extracted from the deciduous teeth ofchildren and the permanent teeth and wisdom teeth of teenagers less than 20 years of age.The cells were subcultured and amplified to observe the morphology and growth of the cells.The surface markers and their differentiation ability were identified to prepare the pulp mesenchymal stem cells.(2)40 healthy female SD rats aged 3months were selected.According to the random number table method,40 rats were randomly divided into four groups: A,B,C,and D,with 10 rats in each group.Group B,C,and D were all injected with papain in the articular cavity for modeling.A blank control group;Group B normal saline control group,group C sodium hyaluronate knee cavity injection group;Group D: endodontic injection of endodontic-derived mesenchymal stem cells into the knee joint;Group A did not do any treatment,group B: blank control group microsyringe,knee cavity injection 0.2ml normal saline;Group C: 0.2ml intravitreal injection syringe for sodium hyaluronate injection into the knee joint;Group D: dental pulp between source of mesenchymal stem cells(third generation)1.0 * 10 ^ 6/0.2 ml,using micro syringe and knee joint cavity injection,once a week,continuous treatment of 4 weeks,rats were observed under color Doppler ultrasound to exceed the knee joint change situation,put to death after the rat,with ELISA detection IL-1 beta,TNF alpha,expressed in synovial joints in the HE dyeing was carried out on the cartilage cells.Results:(1)After adherent culture and passage of cells extracted from dental pulp,cells were observed to gradually form a cell cluster under light microscope,with uniform shape and size,closely arranged cells,showing vortical or parallel growth.The cells with high expression of CD73,CD90,CD105 and low expression of CD34 and CD45 on the cell surface could be induced to differentiate into chondrocytes and adipocytes in the induction medium,meeting the identification criteria of stem cells.(2)Joint cartilage gross observation results show: a week after the modeling of articular cartilage visible dark color,rough uneven,ulcer formation,and the exposure of subchondral bone,extracellular matrix significantly reduced,tidal line disorders,inflammatory cell infiltration,consistent with the performance of osteoarthritis.(3)HE staining score: the surface of articular cartilage in group A and blank control group was even and bright white,without cleft ulcer;the cartilage structure wasdisordered in group B and normal saline group,with decreased chondrocytes and uneven HE staining.C sodium hyaluronate group joint surface rough,A small amount of visible cracks,group D pulp mesenchymal stem cell group joint surface between present A dark gray,there is A crack,according to the MANKIN grading methods statistical analysis: will HE staining grade B compared with group A,C,D group differences were statistically significant(P < 0.05)in group B there was no statistically significant difference compared with group C(P > 0.05),group D and group C differences statistically significant(P < 0.05),(4)ELISA measurement results: The expression levels of TNF-and TNF-were significantly increased in groups B,C and D,and decreased in groups C and D compared with group B.(P <0.05).Conclusion:1.High purity mesenchymal stem cells can be extracted from dental pulp by adherent culture.2.Model of osteoarthritis induced by articular injection of papain.3.Injecting dental pulp mesenchymal stem cells into the articular cavity can effectively reduce the level of inflammatory factors in the articular cavity of rats and improve the score of HE staining MANKIN. |
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