Study Of Autologous Platelet-rich Plasma On Rabbit Articular Cartilage Damage Repair

Objective:Articular cartilage, a special kind of dense connective tissue,whose surface is smooth, has its unique biological properties in order to makeit be an effective transmit and spread the load. So it can reduce the frictionalforce of the contact surface between the two adjacent bone, and can cushionthe vibration because of more ment.The articular cartilage is destroyed in theprocess of degenerative joint disease or violence injury,leading to the articularcartilage damage.Due to lacking of blood vessels and that cartilage cells arethe terminally differentiated cells, the ability for the cartilage in repairing itselfis poor, and which does mot obtain its subchondral bone damage is difficult toheal.There are two traditional method for the treatment of cartilagedamage,one is conservative treatment and the other is surgical treatment.Conservative treatment taking the non-steroidal anti-inflammatory drugs oralor having an intra-articular injection of sodium hyaluronate, only delays thefurther development of the articular cartilage injury, and relieves theirsymptoms, not to be a fundamental solution to the issue of articular cartilageinjury.Surgical treatment is strict to the choose of the patient,and doesn’t havean ideal.We damage the articular cartilage of18rabbits and give anintra-articular injection of the PRP,in order to learn whether PRP has an effectin promoting repair process.We adapt the observations of the morphology andmicroscopic of the repairing tissue so as to ensure their ingredients of the newtissue.And wo also have a further explore to discuss the role of PRP in thepromotion of articular cartilage damage repair process.Methods:1、Grouping:Experiment on18New Zealand white rabbits,aged3-4months,and divide them into3group randomly. The three groupswere executed in1,3,5weeks respectively named1week group,3weeksgroup,5weeks group. All experimental animals left medial condyle cartilage for the control side, right knee medial condyle cartilage experimental side,self-control.2、Blood collection:Each experimental animals were in the ear centralartery slow extraction of about7-8ml arterial,5ml injected into the vacuumtube of the lithium heparin anticoagulant,2ml injected into the vacuum tube ofthe EDTA-K2anticoagulant, spare.3、Preparation of the PRP：Application twice centrifuged prepared PRP,the first centrifugation speed2000r/min, time10min, after centrifugationsyringe erythrocytes junction layer below2mm and discarded, and theremaining part is placed in a centrifuge, the second centrifugation speed2000r/min, time10min, after centrifugation serum layer at the top3/4part bysyringe and discarded, and the remaining part is the PRP. The5ml rabbitarterial blood can be prepared about0.5mlPRP.4、Platelet count：Take2ml blood with EDTA-K2anticoagulanted andPRP into hemocytometer to get the number of the platelets.5、Cartilage damage modeling and intervention:Each experimentalanimals are using the the anterior cruciate middle of the incision to the skin infront of the knee.Cut approach parapatellar medial knee joint capsule, fullyexposed rabbit medial femoral condyle.Scalpel blades manufactured in themedial condyle of the middle part of about the size of2×3mm thickness ofapproximately0.3mm cartilage defects, then the right knee joint cavityinjection previously prepared0.5mlPRP and50ul activator (calcium gluconate,bovine thrombin) left knee has not interfered with treatment. None of theexperimental animals after surgery brake.6、Observations:The experimental animals were killed by airembolism.Incision of the joint capsule and exposed cartilage injury site.General observation the growth,Applications International Cartilage RepairSociety to evaluation.Then drawn from the repair site,application HE andSafranin-O staining.It was observed under a microscope,applications by O’Driscoll histological score.Results:1week experimental group and the control group has been a significant difference in the experimental group has observed cartilage damagezone the surface of a thin film-like tissue formation, safranin O stainingobserved under the microscope after a large number of visible experimentalgroup at the cartilage damage cartilage cell proliferation gathered, but there isno cartilage matrix formation nascent cells, while the control group, themajority of fibroblasts; cartilage defects of the visual observation of theexperimental group and the control group can be found to fix the extent of theexperimental group was significantly better than the control group in threeweeks, under the microscope the observations also showed that theexperimental group large Safranin O coloring cartilage matrix, chondrocyteproliferation strong, while the control group, the lack of cartilage matrix,newborn cells are mostly fibroblasts. General observation in five weeks visibleexperimental group cartilage defect has been fully restored, almost can not seethe traces of cartilage damage, cartilage defects of the control group remainedsignificantly improved compared with the three weeks the group cartilagedefects extent of under the microscope see regenerating tissue and normalcartilage tissue of the experimental group was observed from the cellmorphology, cell distribution and extracellular matrix distribution, there is noobvious difference between the control group is still almost no cartilage matrixformation.Statistical analysis applications rank sum test generally observed scoreresults show for1week in the experimental group and the control groupcompared Z=-2.220, P=0.026(<0.05),3weeks group, the experimentalgroup and the control group compared Z=-2.214, P=0.027(<0.05), fiveweeks in the experimental group and the control group compared Z=-2.333,P=0.020<0.05) were statistically significant, under the microscope observedscore results show weeks in the experimental group and control groupcomparison Z=-2.460, P=0.014(<0.05),3weeks group in the experimentalgroup and the control group contrast Z=-2.530, P=0.011<0.05),5weeksgroup, the experimental group and the control group contrast Z=-2.646, P=0.008(<0.05),were statistically significant. Conclusion:We believe that through this experiment: slow, self-repairarticular cartilage damage, and the new tissue is fibrocartilage, PRP canpromote repair of articular cartilage injury rate, and can stimulate cartilage cellregeneration matrix formation, to restore the original structure.