ABSTRACT
In this study, calcium phosphate nanoparticles with two phases, fluorapatite (FA; Ca(10)(PO(4))(6)F(2)) and hydroxyapatite (HA; Ca(10)(PO(4))(6)(OH)(2)), were prepared using the solgel method. Ethyl phosphate, hydrated calcium nitrate, and ammonium fluoride were used, respectively, as P, Ca, and F precursors with a Ca:P ratio of 1:72. Powders obtained from the sol-gel process were studied after they were dried at 80°C and heat treated at 550°C. The degree of crystallinity, particle and crystallite size, powder morphology, chemical structure, and phase analysis were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Zetasizer experiments. The results of XRD analysis and FTIR showed the presence of hydroxyapatite and fluorapatite phases. The sizes of the crystallites estimated from XRD patterns using the Scherrer equation and the crystallinity of the hydroxyapatite phase were about 20 nm and 70%, respectively. Transmission electron microscope and SEM images and Zetasizer experiments showed an average size of 100 nm. The in vitro behavior of powder was investigated with mouse fibroblast cells. The results of these experiments indicated that the powders were biocompatible and would not cause toxic reactions. These compounds could be applied for hard-tissue engineering.
Subject(s)
Apatites/chemical synthesis , Apatites/toxicity , Durapatite/chemical synthesis , Durapatite/toxicity , Nanoparticles/chemistry , Nanoparticles/toxicity , Animals , Cell Line , Mice , Microscopy, Electron, Scanning , Nanocomposites/chemistry , Nanocomposites/toxicity , Nanocomposites/ultrastructure , Nanomedicine , Nanoparticles/ultrastructure , Particle Size , Powder Diffraction , Spectroscopy, Fourier Transform InfraredABSTRACT
Synthetic hydroxyapatite (HA) has been recognized as one of the most important bone substitute materials in orthopaedics and dentistry over past few decades because of its chemical and biological similarity to the mineral phase of human bone. One solution for reduction the solubility of HA in biological environments is replacing F- by OH in HA structure and forming fluor-hydroxyapatite (FHA) solid solution. In this paper, FHA nanoparticles were successfully synthesized by a sol-gel method. Also, the influence of aging temperature on formation of FHA powder was studied. Equimolar solutions of calcium nitrate tetrahydrate, triethyl phosphite and ammonium fluoride in ethanol were used as Ca, P and F precursors. After aging at different temperatures, the synthesized powders were heat treated at 550 degrees C. The powders were investigated with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), selected area electron diffraction pattern (SAED), energy dispersive analysis of X-ray (EDAX) and zetasizer measurement. The results of XRD proved the presence of fluorapatite (FA) and HA in all samples. In addition, the formation of FHA was confirmed by FT-IR results. XRD studies also showed that the crystallites were in nanometric scale. At the same time, this result was in good agreement with the result of zetasizer analysis.
Subject(s)
Bone Substitutes/chemistry , Crystallization/methods , Hydroxyapatites/chemistry , Nanostructures/chemistry , Nanostructures/ultrastructure , Nanotechnology/methods , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Particle Size , Phase Transition , Surface Properties , Temperature , Time FactorsABSTRACT
In this study 39 macro-morphological features of 8 populations of Z. clinopodioides Lam. were studied to find their diagnostic features for distinguishing their different subspecies in Iran. Micro-morphological characters of epidermis and pollen grains were considered. In order to determine the most variable morphological characters among the species studied, factor analysis based on principal components analysis was performed using SPSS ver. 9. Palynological studies show the general form of tribe Mentheae. According to the present results, the pollen morphology in Ziziphora clinopodioides may be helpful in elucidating the infra specific relationships. Leaf micro-characters of epidermis were shown to be of great importance in the taxonomy of the Z. clinopodioides subspecies. Using complement macro-characters for taxonomic purposes is highly recommended in Ziziphora L.
