Research On Calcium Base Nano Material Deposited With Silver And Zinc Oxide

Nano hydroxyapatite has a good biocompatibility and can inhibit the growth of some tumor cells.It can be used as bone repair biomaterial,scaffold material and controlled release carrier for drug.However,nano hydroxyapatite has a poor antibacterial property and often causes infection.In this paper,both nano silver and nano zinc oxide are deposited on the surface of nano hydroxyapatite to improve its antibacterial property and proliferative ability of osteoblast.Nano hydroxyapatite-based composite were fabricated by three different methods:depositing nano silver and nano zinc oxide together,first depositing nano silver and then depositing nano zinc oxide,first depositing nano zinc oxide and then depositing nano silver.The results indicated that only hydroxyapatite-silver nanocomposite was obtained by the method of depositing nano silver and nano zinc oxide together,while hydroxyapatite-silver-zinc oxide(HA-Ag-ZnO)nanocomposite was gained by each of the other two methods.With increasing the ratio of zinc source to silver source,the characteristic peak intensity of nano zinc oxide in the X-ray diffraction pattern of HA-Ag-ZnO nanocomposite first enhanced and then weakened.When the ratio was 6:1,the peak intensity of nano zinc oxide reached its maximum.The calcination temperature of nano hydroxyapatite had some effect on the deposition of nano silver in HA-Ag-ZnO nanocomposite.Compared with HA-Ag-ZnO nanocomposite prepared using nano hydroxyapatite calcined at 450? as the matrix,nano silver in HA-Ag-ZnO nanocomposite gained using nano hydroxyapatite calcined at 750? as the matrix had a smaller mean size and a narrower size distribution.The substitution of zinc element in nano hydroxyapatite also affected HA-Ag-ZnO nanocomposite.The substitution of zinc promoted the deposition of nano zinc oxide on the surface of nano hydroxyapatite,while the size of deposited nano zinc oxide was slightly bigger.The result of immersion in simulated body fluid showed that the deposition of nano silver and nano zinc oxide on the surface of nano hydroxyapatite can simultaneously increase the release rate of silver ion and zinc ion;the deposition of nano silver on the surface of nano hydroxyapatite increased the drop of calcium ion concentration of simulated body fluid,while the deposition of nano zinc oxide had an oppsite effect.