The Study Of Nerve Growth Factor On Fracture Healing

Objective:To investigate the effect of nerve growth factor(NGF)on fracture healing,and to study the role of bone morphogenetic protein-2(BMP-2) induced osteoblast.Methods:Sixty(60)Kunming mice were randomly divided into four groups each containing 15 mice.Unstable cartilage was established in the middle of femoral shaft fractures in these models.Group A was used as an experimental group,Group B as a positive control group,Group C as a synergistic group and Group D as a negative control group.The partial fracture stumps of Groups A,B,C and D were treated with NGF and Normal Saline, BMP-2,BMP-2 and NGF,and Normal saline respectively.Based on their fracture site 5 mice were selected and sacrificed from each of the 4 groups at intervals 14,21,and 28 days.Before the mice were killed arteriovenous blood was taken from their eye-ball(in vitro MORIZUMI).Radiographs were taken of the selected specimens while biochemical and histological analysis were also done.All images were evaluated by the pathology image system of LEICA QWIN LIVE.The data were then analysised with SPSS 13.0 statistical software using randomise design analysis of variance and factorial design analysis of variance test.Results:At 14 days the serum Alkaline Phosphatase(AKP)were higher in Groups A,B and C than in Group D.The net weight of callus had no significant difference in Groups A and D,nor in Groups B and C,but there was significant difference between Groups B,C and Groups A,D.After14,21 days the AKP of callus tissue were higher in Groups A,B and C than in Group D.After 21,28 days Groups A,B and C had the net weight of callus,bone tissue in the trabecular surface index of osteoblast(IOB),average area of trabecular bone area(TV)and mean trabecular width(TW)higher than those in Group D.After 14,21,and 28 days the calcium content of callus tissue and gray degree values of the radiographs were higher in Groups A,B and C than in Group D.Conclusion:NGF promotes the healing of fractures.NGF possesses synergistic effect on ectopic bone formation induced by BMP-2.