Revascularization And Ostegenesis During Repair Of Bone Defects With N-HA/PA66/oste-Oblast/VEGF165Tissue-engineered Bone

Background: The repair of large bone defect is a tough clinicalproblem, for the orthopaedic surgeons.Crrently,there are many kinds oftreatments about this problem,but they all have their own defects.Thetissue-engineered bone is a new way to solve this problem and is currentlyin hot research.That makes the repair of large bone defect a dificulty is thepoor blood supply in the bone defect,so it is of great significance toconstruct a new tissue-engineered bone that can revascularize fastly.Themain methods of construction are use vascular endothelial cells、microsurgical techniques、growth factor and genetic technologies.Thethree methods before helping the revascularization of the graft mostly byexogenous ways,so the results are not satisfactory. However,genetictechnology has some advantages. Vascular endothelial growthfactor(VEGF) is the most important factor that can promote angiogenesisat the bone fracture.We transfer the gene of VEGF into osteoblast with thehope it can express constantly、stably and then accelerate the repair of thebone defect. Objective: Using the new tissue-engineered bone(n-HA/PA66/Orbital osteblast/VEGF165) to repair the rabbit’s radius bone defecthoping that it can express constantly、stably and accelerate the repair ofthe bone defect and then provie a theoretical basis for the construction of anew tissue-engineered bone that can revascularize fastly.Materials and methods: Creating the annimal models of bilateralradius bone defect in56new white rabbits which are devide into twogroups (A、B). In A group annimals are inplanted with n-HA/PA66on theleft defect(A1) and with n-HA/PA66/VEGF165composite materials onthe right side(A2) in B group annimals are inplanted with n-HA/PA66/Orbital osteblast/VEGF165composite materials on the left defect(B1) andwith n-HA/PA66/Orbital osteblast composite materials on the rightside(B2).B1group is the test group,the another three groups are contolgroups.At2、4、8、12weeks after operation,the annimals are observded bygross DR radiography、histological、vessl count、SEM ananysis.Results: The osteogenetic activity and revascylarization in B1groupwas more superior than other groups at each time point,there wasstatistically significant diffrence between B1group and other groups onthe vessl count at each time point(p<0.05);the revascularzation andosteogenic activity in A1、A2groups was not to be compared with B1、B2groups; no diffrence was observed betweenA1、A2groups.Conclusions: The new tissue-engineered bone(n-HA/PA66/Orbital osteblast) has perfect effect on osteogenesis and can promote rapidformation of vessel in early bone defects repairing,thus it can speed up therepairing of bone defects. In conclusion,it has a further research prospect.