The Study On Delivery System Of Growth Factor To Accelerate The Healing Of Mandibular Fracture

The purposes of this study is to investgate the function and mechanism of delivery system of basic fibroblast growth factor (bFGF) and bone morphogenetic (BMP) to accelerate the healing of mandibular fracture,and develop clinical materials to supply new therapeutic method for mandible fracture.1. Study of bFGF delivery system to accelerate the healing of mandibular fractureMethod: bFGF collagen films were acquired by mixing 50 μg bFGF with the 4 ml 1% collagen, then drying and freezing under the vacuum circumstance, alginate calcium gel was prepared by mixing 50 μg bFGF with 4ml 1.5% alginate sodium, then adding CaCl₂ to gelatinate. The mandibular fractures of 32 mature New Zealand rabbits were prepared. Composite film of bFGF and collagen or composite gel of bFGF and alga calcim were used in study groups, only 50 μg bFGF was used in contol group, and none of the growth factor and delivery system were added in blank control group. X-ray, histomophometice and immunochemical examwere taken at the 2,4, 8,12week after surgery. Result: the rate of mandibular fracture healing in study group is apparently faster than control group. In study groups, bFGF expressed in high intense for 8 weeks, and large amount of vassals were formed in fracture area. The deformation rate of collagen is faster than alginate calcium gel. The results demonstrated that bFGF delivery system can promote the healing rate of mandibular fracture and release bFGF continuously during the healing period of bone fracture. 2. Study of BMP delivery system to accelerate the healing of mandibular fractureMethod: BMP collagen films were acquired by mixing 40mg BMPwith the 4 ml 1% collagen, then drying and freezing under the vacuumcircumstance, alginate calcium gel was prepared by mixing 40mg BMP with4ml 1.5% alginate sodium, then adding CaC^ to gelatinate. The mandibularfractures of 24 mature New Zealand rabbits were prepared. Composite filmof BMP and collagen or composite gel of BMP and algmate calcium wasused in study groups, and none of the growth factor and delivery systemwere added in blank control group. X-ray, histomorphological andhistochemical exam were taken at the 2, 4, 8,12week after surgery. Result:the rate of mandibular fracture healing in study group is apparently fasterthan control group. In study groups, BMP expressed high intense for 8weeks. No differences were found in vassals' formation between studygroups and control group. There were no statistical differences between twostudy groups in new bone and expression of BMP. The deformation rate ofcollagen is faster than alginate calcium gel. The results demonstrated thatBMP delivery system can promote the healing rate of mandibular fracture and release BMP continuously during the healing period of bone fracture.This study has indicated that bFGF/collagen filniN bFGF/alginate calcium gek BMP/collagen film and BMP/alginate calcium gel all can accelerate the healing of mandibular fracture of the rabbits and decurtate the period of union of mandibular fracture.