| Objective:Platelet-rich plasma(PRP)has been found to be rich in many growth factors,and with multifaceted functions,in tissue repair and regeneration.It has been widely used in clinical field.The study found that PRP showed good potential in promoting angiogenesis,and it was more effective when combined with biological carrier,Therefore,our research aimed to explore hypothesized mechanism of action of heparin-conjugated fibrin loaded platelet-rich plasma(HCF-PRP)promotes neoangiogenesis and tissue regeneration in rabbit nontraumatic osteonecrosis of the femoral head repairing processes.The rabbit model was induced by methylprednisolone and lipopolysaccharide.It will provide new strategy to treating patients with chronic ischemic of extremities.Methods:Useing 6-8 week old healthy New Zealand 32 rabbits,treated with lipopolysaccharide and dexamethasone,in order to establishing the animal model of avascular necrosis of the femoral head,After 6 weeks of injecting the drug,the study had been evalutaing avascular necrosis of the femoral head by MRI examination,for screening model of rabbit.The experimental animal model(n=27)were randomly divided into 5 groups.Group A(n=3)was control group,without any treatment.B group(n=6)(R)underwent right hindlimb femoral puncture,and the left hind limb(L)without any treatment.C group(n=6)underwent right femoral bone puncture and the treatment of heparin conjugated fibrin(HCF),and the left hind without any treatment.D group(n=6)underwent right femoral bone puncture and PRP injection,the left hind without any treatment.E group(n=6)underwent right femoral bone puncture and HCF-PRP injection,the left hind not any treatment.After eighth weeks treatment,each group has been determined treatment effects by MRI.Then the rabbit femoral head specimens were stained with hematoxylin eosin(HE)staining and vascular endothelial growth factor(VEGF)immunohistochemical staining,pathological observation,microvessel count(MVC)semi quantitative analysis of VEGF expression and angiogenesis,to observe the situation within the organization.SPSS statistical software was used for statistical analysis and comparison of the above data,P<0.05 was statistically significant,P<0.01 was statistically significant.Results:(1)84.38%(27/32)of rabbit animal models were successfully established assessed by MRI.(2)The experimental animal to be examined by MRI after eighth weeks,we found that the recovery of each experiment animal was different.The E group rabbits R lateral femoral head showed the best therapeutic effect,the followed was the D group R lateral femoral head,the last were the A group bilateral femoral and B,C,D,E group L lateral femoral head.In addition,the responses of B,C group R lateral femoral head were between A,D group.(3)The pathological section of femoral head showed,the degree of necrosis of the E group of experimental rabbit R lateral femoral head was the most slight,the R side of D group was the second,then the A group bilateral femoral and B,C,D,E group L lateral femoral head suffer most from this ischemia.Similarly,the lesions of B,C group R lateral femoral head were between A,D group.(4)There was significantly differences between groups about R side of the MVC(P<0.01).The E group was the largest as opposed to the A group.But here was no differences between groups about L side of the MVC(P>0.05);And there were significantly difference between the R side and L side in MVC data within groups B,C,D,E,(P<0.01).(5)The E group L lateral femoral head was the highest when comparison of VEGF expression(P<0.05),in contrast,the A group bilateral femoral and B,C,D,E group L lateral femoral head were the least.(D vs A&E,P<0.05,the other P>0.05).(6)There was significant correlation between the number of microvessels and the expression of VEGF in rabbit femoral head,the correlation coefficient was 0.956(P<0.01).Conclusions:1.The animal model of avascular necrosis of femoral head can be successfully established by the combination of hormone and endotoxin injection,and the success rate is high;2.In our rabbit model,we found obvious vascular tissue regeneration,collateral circulation established rapidly,and the rapid restoration of ischemic necrosis of the femoral head tissue via direct puncture injection of HCF-PRP.The HCF-PRP may be a promising target to accelerate recovery for chronic ischemic disease of the limbs therapy. |
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