The Study Of Superparamagnetic Chitosan (pDsVEGF165)gelatin Microsoheres For The Cranial Defects

Objective To observe the advance of cranial bone defects healing of the porosityscaffolds biological artificial bone filled with the superparamagnetic chitosan plasmid(pDsVEGF165)gelatin microspheres (SPCPGM) within the oscillating magnetic feild, to investigate the effect of osteogenesis and clinical application value.Methods⑴Product sufficent recombinant plasmids vascular endothelial growth factor VEGF165(pDsVEGF165) that can expresse in the eukaryotic cells. The restriction endonuclease enzyme analysis with agarose gel electrophoresis were employed to identify of the recombinant plasmid (pDsVEGF165). The concentration coefficient and purity of the plasmid(pDsVEGF165) were measured by a nucleic acid and protein analyzer.⑵The SPFCN were prepared by the chemical co-precipitation, the structure of the SPFCN was surveyed with Vibrating Sample Magnetometer.⑶The super paramagnetic chitosan plasmid (pDsVEGF165)compounds (SPCPN) were prepared with combination.⑷The SPCGM and SPCPGM were all prepared by the method of emulsification cross-linked. The nahlock porosity scaffolds were made of the cement of the calcium phosphate ceramic(CPC)and gelatin microspheres composite.⑸The 60 adult New Zealand white rabbits were randomly divided into 5 groups, (Group A) empty CPC porosity scaffolds; (Group B) SPCGM + CPC porosity scaffolds; (Group C) SPCGM + CPC porosity scaffolds + oscillating magnetic field, (Group D) SPCPGM+ CPC porosity scaffolds;(Group E) SPCPGM+ CPC porosity scaffolds+ oscillating magnetic field. Then the specimens were obtained in 2, 4, 8 and 12 weeks postoperatively. General observation; istological examinations and X-rayect were applied to evaluate the ability of cranial bone defects healing in different groups.Result⑴Agarose gel electrophoresis shows that pDsVEGF165 plasmids have a goal fragment. The concentration of plasmids was1.48±0.05mg/ml.⑵The content of nitrogen of SPFCN were 0.0054mg/L.The result of VSM directions that the SPFCN possesses the characteristics of super paramagnetic material.⑶This study indicates that SPCPGM can promote the osteogenesis in cranial bone defects healing by oscillating magnetic field. E groups are better than others. At 4 weeks postoperatively, the CPC porosity scaffolds were beginningly partly degraded and the new bone formation. The order of effectiveness for the osteogenesis is as following: Group E> Group D> Group B,C≈Group A empty biological activity artificial bone. Conclusion The composite scaffolds of the gelatin microspheres and the CPC porosity were degraded more fasterly. Under the oscillating magnetic field the SPCPGM was delivered controling , promote the transfection of plasmids. The composite scaffolds promote the osteogenesis of cranial bone defects and vascularization...