| Objective:PDGF combined fibrin gel is local injection of rabbit tibia fracture healing model,through the Micro-CT HE staining methods of the serum biochemical indicators and biomechanical test,from the aspects of imaging and tissue morphology observation study PDGF influence on fracture healing repair,for fracture healing and delayed healing cure provides a new basis and choice of the patientMethods:Healthy New Zealand White Rabbit,male,48,weighing about 2.0-2.5kg,following the principle of sterility,artificially caused the middle tibial fracture of the right side of the rabbit,and then used electrocautery to destroy the periosteal tissue around the fracture,grind the bone at the end of the fracture to cause a certain range of defects,and then internally fixed with a 2.5mm knell needle,The periosteum at the end of the fracture is destroyed at the same time,resulting in impaired blood transport at the end of the fracture,the diameter of the Knov needle used for intraoperative internal fixation was smaller than the diameter of the tibial bone marrow cavity,and the axial instability of the internal fixation of the fracture end was artificially caused,and operate after 6 months,the tibia fracture of the great white rabbit was observed to be unhealed,indicating the successful establishment of a fracture non-healing model.After the model is established,Random number table method,divided into A groups(blank control group),B group(fibrin gel group),C group(PDGF group),D group(PDGF + fibrin gel group)four groups by random number table method.A group 12 in each group,each group was injected with drugs locally percutaneously in the fracture after successful modeling,7 consecutive days,1 time per day,And injectables of each group of drugs are:B group(200u L fibrin gel),group C(200ug PDGF + 1m L normal saline),Group D(200u L fibrin gel + 200 ug PDGF + 1m L normal saline),Group A was injected with the same amount of saline as the remaining three groups,and the timing and frequency of administration were consistent with those of the remaining three groups.After injecting the drug for 8w,the experimental white rabbit took blood and left the standard and executed it,performed Micro CT to observe the healing of the fracture end of each group and detect the bone ore content,bone mineral density and bone volume fraction of the fracture end of each group,and after the Micro CT examination,the specimen of the bone scab tissue around the fracture of each group was taken,and the HE staining and histological observation were carried out after calcium removal.The content of VEGF and IGF-1 in the serum of rabbits at 4 weeks and 8 weeks was determined by protein chip method.Using the statistical software SPSS 25.0,the obtained data are statistically analyzed,the data obtained by statistical analysis is statistically analyzed,measurement data are expressed as standard deviation(x,s),and each group of data is analyzed and processed by a completely randomly designed one-way ANOVA method,the LSD method compares the inter-group data and performs variance homogeneity test and normality test before analysis,and the test levels a=0.05 and P<0.05 are statistically sense.Results:Micro CT examination results After 8w of injection,Micro CT was used to analyze the changes of bone tissue morphology and bone mass in and around the fracture area.The bone ore content,bone mineral density and bone volume fraction of group D were apparently higher than the remaining three groups,and group C was higher than group A and group B and lower than group D,and there was no clearly distinct between groups A and B.Histological observations At the end of the Micro CT analysis,the scab specimens of each group of fracture areas were taken,and histological analysis is performed after fixation,decalcification,dehydration and dyeing,and the results showed that the trabeculos of group D was increased and intertwined into a network,fibrous scabs decrease and osteoscluscular scabs increase,and mature plate-like bone was visible;Formation of some trabeculents in group C,and some mature plate lamellar bone and bone scab formation were visible;the increase of bone scab in the group A and the fibrin gel group of group B was not obvious.The tissues are filled with a large number of fibrous scabs and trabeculates of immature bone.Serum biochemical index results By protein chip method,the levels of VEGF and IGF-1 in serum were measured,and the results demonstrated that when injecting for 4 weeks,The serum content of VEGF and IGF-1 in the PDGF group and group D PDGF combined with fibrin gel group was clearly higher and the distinct was clear(P<0.05)comparing group a and group b,and there was no apparent distinct between the PDGF group and the combined group;after 8 weeks,the serum content measured in the combined group D was better than that in the remaining three groups,and the C group was higher than the A and B groups and lower than the D group,the distinct was apparent,and the distinct between the control group and the gel group was not clear.Biomechanical test results After dissecting the soft tissues in the fracture area,a commercial material analysis system(Instron 3343 material testing machine)Used to Perform a three-point bending test to record the ultimate load of the tibia under pressure,and analyze and calculate the mechanical properties of the fracture area.Statistical analysis and calculation showed that there was little distinct between group A and group B,and the increase in group C was clear,and the increase in group D was the most prominent in group D treated with PDGF combined with fibrin gel,indicating that PDGF combined with fibrin gel was more effective and promoted bone formation in fracture area for a long time.Conclusion:1.Platelet-derived growth factor alone can significantly improve tibial fracture nonunion in rabbits.2.Fibrin gel is a very good slow-release agent and carrier of platelet-derived growth factor.A combination of the two has a longer effect on promoting fracture healing than the use of platelet-derived growth factor alone,and the later effect is more obvious. |
PDF Full Text Request