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[The preparation and characterization of sol-gel derived zinc modified carbonated hydroxyapatite].

OBJECTIVE
To prepare zinc-modified carbonated hydroxyapatite (Zn-CHA) coating material via sol-gel method and explore the influence of zinc substitution on physical and chemical properties of biomaterial samples.


METHODS
Two kinds of samples with different zinc content and Ca/P molar ratio were prepared. One was fabricated with 4% zinc and the Ca/P molar ratio was 1.67. Another was prepared with 8% zinc and the (Ca+Zn)/P molar ratio was 1.67. The coating samples were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM). Furthermore, the zinc ions releasing ability of the coating samples were investigated by atomic absorption spectroscopy (AAS).


RESULTS
XRD results revealed that the coating samples contained hydroxyapatite phase. After determination by FTIR, the biomaterial samples were found to contain carbonate and resemble biological apatites. High homogeneous and porous surfaces of coating samples were observed in SEM micrographs. According to the results of dissolution test, zinc was incorporated into hydroxyapatite lattice structure or surface absorbed when calcium was insufficient or sufficient respectively.


CONCLUSION
The results demonstrate that phase-pure zinc-modified carbonated hydroxyapatite might be prepared through simple sol-gel method and have favorable antibacterial effect.