The Research Of Transfection Efficiency Based On Hydroxyapatite Nanoparticles With Chitosan Surface Modification As Gene Carrier

Objectives:To evaluate the dispersion stability and transfection efficiency of hydroxyapatitie(HA) nanoparticles as Gene Transfer Carrier, which was surface modified by chitosan surface,and to lay the theoretical foundation for how to enhance the dispersion stability and transfection efficiency of hydroxyapatitie(HA) nanoparticles.Method:1,0.0125%wt Chitosan solution was added into HA suspension for surface modification;2,The pH of HA nanoparticles with chitosan surface modification was tested by pH value measurement,and the Zeta potentials were tested at different pH to evaluate the surface charge of HA;3,The composite morphology and particle size of HA-CS nanoparticles were observed by transmission electron microscope(TEM). The ability of modified HA nanoparticles in absorbing and protecting DNA, and the way of HA-CS/DNA dissociation were analyzed by agarose gel electrophoresis analysis and ultraviolet spectrophotometer;4,Subsequently, the modified HA were used to transfer plasmid pEGFP-N1 into HepG2 liver cancer cells,Hela cervical cancer cells and SW620 colon cancer cells,to evaluate the transfection efficiency of hydroxyapatitie(HA) with chitosan surface modification.Results:The PH of HA nanoparticles with chitosan surface modification was 4.14,the Zeta potentials of HA nanoparticles with chitosan surface modification were positive in both acidic and neutral environments,but negative in alkaline environment;The modified HA can bind DNA efficiently in neutral environments;The diameter of HA and CS nanoparticles were about 20～90nm under TEM observation,there were some CS particles around the HA particles,had part of reunion and good dispersion;The load of gene carder of HA with chitosan surface modification was higher than that of HA.The modified HA nanoparticle had the ability of carrying and protecting DNA;The absorbed DNA can be washed off by PB solution;The transfection efficiency of HA nanoparticle with chitosan surface modification was higher than that of the HA and CS without modification,but there was no significant difference among the three different cancer cells.Conclusions:Compared with HA nanoparticles,HA nanoparticles with chitosan surface modification had better dispersion,higher Zeta potentials,and can enhance the transfection efficiency and the load of gene cartier.