Combined Application Of Exogenous TGF-β2 And IGF-Ⅰ On Fracture Healing In Rats

Objective: Comparative observation of exogenous transforming growth factor-β2(TGF-β2), insulin-like growth factor Ⅰ(IGF-Ⅰ) and the combined effects of two growth factors during fracture healing in rats under application.Method:(1) 120 SD rats were randomly divided into 4 groups. Build the right tibia fracture model. A group of local fracture after injection of exogenous insulin-like growth factor Ⅰ(IGF- I), B group of local fracture after injection of exogenous transforming growth factor beta 2(TGF- beta 2), C group of local fracture after injection of exogenous insulin-like growth factor Ⅰ and transforming growth factor beta 2(TGF- beta 2), D group was the blank controlgroup.(2) At 2 and 4 weeks, each group were randomly selected six rats, observe the bone hard tissue growth of newborn.(3) At 2 、 4 and 6 weeks, six rats were randomly selected by X-ray observation of fracture healing, the callus growth, parallel imaging score.(4)Each group at 1 and 3 weeks, six rats were randomly selected were stained with HE from callus tissue, to observe the callus cells.(5) Each group in 6 weeks, six rats were randomly selected for test in each group, three point bending biomechanics.Results: General observation: After two weeks, small groups can be palpable and newborn hard tissue, Agroup and D group nascent hard tissue hardness is relatively soft,newborn hard tissue more fibrous bone callus tissue, a small amount of cartilage tissue growth. Group B and Group C is relatively nascent hard tissue A larger group and D group, but C group larger and more rigid hard tissue, including cartilage tissue as the C group, group B cartilage and fibrous tissue almost. Four weeks after surgery, D、A、B、C groups increasing range of hard tissue, increasing the hardness of each group of hard tissue, mostly newborn bone bone callus. Imaging observation and rating: the second week after surgery, four groups were clearly visible fracture line, each group had a little outside of callus formation, C external callus relatively high. After the fourth, six weeks,four groups were significantly outside the callus formation, D、A、B、C external callus increases, radiographic score increases. Histological observation: After one week, the groups were observed in callus tissue granulation tissue, fibrous tissue ingrowth, group C see a small amount of cartilage cells to grow into. After three weeks, four groups were seen interwoven mesh of trabecular bone, D、A、B、C are arranged in each group gradually rules and orderly. Biomechanical observed: six weeks after surgery, D、A、B、C of each group tibia bending strength increases, there are differences, P <0.05 between groups C and bending strength of A 、 B 、 D, the difference statistically significant.Conclusion: Local application of exogenous transforming growth factor beta 2(TGFbeta 2) or insulin-like growth factor Ⅰ(IGF- Ⅰ) can promote the healing of fracture, but TGF- beta 2 has stronger effect, synergistic effects of combined application of the two promote fracture healing, stronger effect.