Study On Alveolar Bone Defects By Non-replicating Recombinant Adenovirus Co-Expressing OPG And BFGF

Periodontitis is one kind of chronic destructive disease, damages the supporting periodontral tissue, particularly the alveolar bone's destruction and loss may cause the tooth to fall off. At present through general clinical treatment method, like supragingival scaling, root planing, flap surgery, as well as guided tissue regeneration (GTR) and so on, neither restores the normal the alveolar bone crest, nor forms the new attachment. The tissue engineering technology and gene therapy technology's starting and developing, could provide the brand-new mentality and method for complete periodontal tissue regeneration.This research starts from the bone absorption-reconstruction mechanism. Increasing the osteoprotegerin (OPG) secreting in the periodontal tissue using the gene therapy technology, could suppress the function of the receptor activator of nuclear factor kappa B ligand (RANKL), blocks the osteoclast to multiply, differentiate and mature. Simultaneously using the basic fibroblast growth factor (bFGF) promoting periodontal tissue regeneration could create one favor environment to restore periodontal tissue defect and achieve this purpose which the alveolar bone defect restored and the new attachment formed..ObjectiveThis research in advance constructs co-expressing osteoprotegerin (OPG) and basic fibroblast growth factor (bFGF) based on replication deficient adenoviral vector. Then Class III defects in 6 dog's two-sided mandible premolar root furcation were created. Set collagen membrane in the damage area which including or not including the reconstructed adenovirus, observe periodontal tissue defect repairing situation in the different time. The purpose is discussing the alveolar bone defect restored by replication deficient adenoviral vector based on osteoprotegerin (OPG) and basic fibroblast growth factor (bFGF) as the exogenous gene and unifying the GBR technology. The research provides the new method and the new mentality to treat periodontitis using tissue and gene engineering technology.MethodsRecoverying and the mass culturing 293 cells, then take replication deficient adenoviral vector co-expressing osteoprotegerin (OPG) and basic fibroblast growth factor (bFGF) two kind of gene to infect 293 cells. After infected, purifies and extract virus, then frozen. Six health grown-up hybrid dogs were chosen as the experimental subject. Surgically create the alveolar bone defect at the 3rd and 4th premolar root furcation area, in either the right or the left mandibular. Using the stochastic method, divides into 6 week and 12 week two time section each 3 dogs, each time section divides into the experimental group, the material control group and the blank control group. Experimental group:Turn the flap to make the alveolar bone defect, set the collagen membrane by dropping the reconstructed adenovirus, suture flap, then inject adenovirus; Control group:Turn the flap to make the alveolar bone defect, set the collagen membrane, sutures flap; Model group:Turn the flap to make the alveolar bone defect, sutures the flap directly.The surgery latter 6 week and 12 week animal were executed to take specimen,observe the bone damage regeneration through roughly observation, x-ray and histology observation.ResultsSurgery latter 6 weeks:The experimental group, x-ray obvious bone damage area has the new bone formation, the histology sees the newborn bone to fill the damage area; The control group, x-ray obvious bone damage area has the new bone formation, the histology sees the newborn bone calcification degree to be low; The model control group, x-ray sees the bone damage area not to have the newborn bone formation, the histology to see bone trabeculae to be sparse, mainly the loose connective tissue. Surgery latter 12 weeks:The experimental group, x-ray obvious bone damage area newborn bone quantity increasing obviously, the histology sees the new alveolar bone to fill the root furcation area, bone trabeculae is compact; The material control group, x-ray obvious bone damage area new bone quantity increasing obviously, but not achieving the root furcation crest crown, the histology sees the bone damage area to have the massive new alveolar bone but not filling the root furcation area; Blank control group, x-ray and histology performance is similar to surgery latter 6 weeks.ConclusionReplication deficient adenoviral vector based on osteoprotegerin (OPG) and basic fibroblast growth factor (bFGF) as the exogenous gene may promote the dog alveolar bone regeneration.