Biomechanics of Bone / Bone Biomechanics
Hoda Salemi; Ali Asghar Behnamghader; Mohammad Reza Baghaban Eslaminejad; Mohammad Ataei
Volume 6, Issue 4 , June 2012, , Pages 249-255
Abstract
Collagen and Hydroxyapatite (HA) nanoparticles are significant constituent of the natural bone. In this study, the effect of collagen on the morphological and phase characteristics of calcium phosphate nanoparticles was investigated. The synthesis reaction was initiated by mixing H3PO4 as phosphorous ...
Read More
Collagen and Hydroxyapatite (HA) nanoparticles are significant constituent of the natural bone. In this study, the effect of collagen on the morphological and phase characteristics of calcium phosphate nanoparticles was investigated. The synthesis reaction was initiated by mixing H3PO4 as phosphorous source and CaCl2 as calcium source in presence of Collagen Type 1. Collagen concentration in suspension and Ca to P ratio was 1% and 1.67 respectively. The morphology and structure of samples (with collagen and without collagen), heat treated at 600 0C were characterized by X-Ray diffraction (XRD), Fourier transformation infrared (FTIR) and Scanning electron microscopy (SEM). More fine and flake-like shape particles were observed in the SEM images of sample synthesized in the presence of collagen compared to the control sample which was constituted of larger granular particles. The XRD results revealed the powders were composed of hydroxyapatite and octacalcium phosphate and the sample synthesized in the presence of collagen was less crystalline. The amide bands of collagen and P-O and OH characteristic peaks were identified in FT-IR spectra.
Nano-Biomaterials
Rouzbeh Kazemzadeh; Ali Asghar Behnamghader; Saeed Hesaraki; Fateme Hazrati
Volume 3, Issue 2 , June 2009, , Pages 127-133
Abstract
Magnesium-contained Hydroxyapatite Nano powder was synthesized by wet chemical method using calcium nitrate tetra hydrate, magnesium nitrate hexa hydrate and di ammonium hydrogen phosphate in the presence of Glutamic acid. According to thermal analysis (STA) findings the samples were calcinated at specific ...
Read More
Magnesium-contained Hydroxyapatite Nano powder was synthesized by wet chemical method using calcium nitrate tetra hydrate, magnesium nitrate hexa hydrate and di ammonium hydrogen phosphate in the presence of Glutamic acid. According to thermal analysis (STA) findings the samples were calcinated at specific temperatures and characterized by XRD, FTIR and TEM analysis. XRD results showed the that b-TCP ((Ca1-xMgx)3(PO4)2) was the dominant phase at 920°C. No characteristic peaks of hydroxyapatite were observed at that temperature. In contrast, the sample which was synthesized in the absence of Glutamic acid, contained both hydroxyapatite and b-TCP phase. The Findings showed a rapid decline in degree of crystallinity at 90°C with presence of Glutamic acid in reaction media. Transmission electron microscopy (TEM) observations on heat treated samples at 480°C revealed that using Glutamic acid has noticeable effect on crystallite size instead of its growth orientation. Dimensions of biomimetic nanoparticles as observed by TEM were 150x60nm and in the witness sample was 500x150nm. According to Scherrer formula for crystallite size, the size of the witness sample was calculated about 40nm. However, because of low degree of crystallinity it was impossible to calculate the size of Glutamic contained samples.
Nano-Biomaterials
Babak Farsadzadeh; Ali Asghar Behnamghader; Sedighe Joughedust
Volume 3, Issue 2 , June 2009, , Pages 151-160
Abstract
In this study hydroxyapatite (HA), flour-hydroxyapatite (FHA) and fluorapatite (FA) nanopowders synthesized by sol-gel route. Theses powders are used as biocompatible materials for bone replacement and teeth restoration. Ammonium fluoride (NH4F MERK), calcium nitrate [Ca(NO3)2,4H2O MERK] and triethyl ...
Read More
In this study hydroxyapatite (HA), flour-hydroxyapatite (FHA) and fluorapatite (FA) nanopowders synthesized by sol-gel route. Theses powders are used as biocompatible materials for bone replacement and teeth restoration. Ammonium fluoride (NH4F MERK), calcium nitrate [Ca(NO3)2,4H2O MERK] and triethyl phosphite [TEP, (C2H5O) 3P MERK)] were used as F, Ca and P precursors respectively. Triethyl phosphite was first hydrolyzed in ethanol with a small amount of distilled water. To prepare FHA and FA, an appropriate amount of the NH4F powder was added directly to TEP solution. The appropriate amounts of TEP solution was added dropwise to the calcium nitrate solution to yield a stoichiometric ratio of Ca/P=1.67. The resulted solution stirred for 1 h and aged at 25°C for 24 h and 40°C for 72h afterward. After oven drying at 80°C, the powder samples were heat-treated at 550°C for 1 h in air. Microstructural characteristics, powder morphology, chemical structure and phase analysis and in vitro study were performed by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR), Zetasizer instrument and cell culture method. Fluoride-substituted hydroxyapatite powders (FHA) and Fluor apatite (FA) were successfully fabricated via a sol–gel technique with the incorporation of different levels of fluoride ions. Nearly complete substitution of the OH¯ by F¯ occurred with heat treatment, which was confirmed by FTIR analysis. The particle size distribution of powders evaluated by a zeta-sizer instrument was 100-160nm. The XRD results showed that the crystal size of powders is 20-50nm. The phase stability and crystallinity were different depending on the level of fluoride substitution. Moreover, the crystallinity and crystallite size of the powders increased with fluoride substitution. These improvements in the crystallization and phase stability of the apatite structure, resulting from the fluoride substitution via the sol– gel process, suggest enhanced performance of the FHA powders. The cellular response to the HA, FHA and FA powder was assessed by an in vitro culture method using fibroblastic L929 cells. After culturing for 3 days, the results showed that the number of cells increased with increasing fluoride substitution.
