Properties Of Hydroxyapatite Powders Research Articles

Characterization and in vitro evaluation of hydroxyapatite from Fringescale sardinella bones for biomedical applications

In the present study, hydroxyapatite (HA) powder was synthesized through heat decomposition method. Along with the synthesization, the effect of calcination temperature on the physicochemical properties, antibacterial activity, and cell studies was evaluated. The results of the study revealed that calcination temperature had a great impact on the properties of HA powder. In addition, the X-ray diffraction (XRD) diffractograms and texture coefficient of the synthesized powder portrayed that a highly crystalline structure was obtained at 900 and 1,200 °C. In addition, the presence of hydroxyl and phosphate vibration peaks exhibited by Fourier transform infrared (FTIR) spectra confirmed the HA formation. Looking into the results, it was discovered that the Ca/P ratio was dependent on the calcination temperature. From the results of in vitro bioactivity, the antibacterial test showed that HA was insensitive to E. coli bacteria. The in vitro osteoblastic evaluation via cell viability through MTT assay affirmed the biocompatibility of HA powder. These capabilities give the potential of applying HA powder from Frinsgescale sardinella bones in bone tissue regeneration.

Wear behavior of hydroxyapatite reinforced polymer composite for biomedical applications

In medical fields, hydroxyapatite (HA) is used for restoring the human bones and teeth. Nowadays, newer bio composites are being developed to replace the broken or removed teeth in human using hydroxyapatite. The original teeth may be removed from human, due to various reasons such as tooth decay, periodontal disease and gum diseases. Due to the bioactivity property of HA, it helps the tooth to grow. In this work, tribological properties of HA powder reinforced composite are investigated. Three most important factors that affect the properties of the composites were chosen and varied during wear testing of the composites. The HA powder weight %, applied load (P) and sliding distance (SD) were varied on the basis of Taguchi’s experimental design. Analysis of variance (ANOVA) and (Signal to Noise) SN ratio analysis was used to study the influence of each factor on the specific wear rate (SWR). It was concluded that the HA wt% highly influences the SWR of the composite during pin on disc testing.

Effect of Calcination on Microstructure Development and Properties of Hydroxyapatite Powders Extracted from Human and Bovine Bones

ABSTRACTThis study represents a comprehensive discussion of hydroxyapatite (HAp) formation from human and bovine bones. The phase formation and surface morphologies of prepared HAp powders were determined by XRD and SEM analyses, respectively. TEM was employed to understand the internal compositions with high magnifications and particle size. FT-IR characterizations provided information about molecular interactions and structures. In order to understand the effect of heat treatment at different temperatures and ultimately to get the desired morphology/particle size of the HAp powders derived from human and bovine, the powder samples were calcined at 700° to 1100°C with an interval of 100°C. At 700°C, the organic components were removed and finally, a carbonate apatite was obtained. The degree of crystallinity and crystallite size were noticed to increase progressively with calcination temperature. The overall results showed that the calcination temperature highly influenced the properties of HAp powders derived from human and bovine bone samples. As expected, higher temperatures led to more pure form of HAp with higher degree of crystallinity, larger crystallite size, and a less porous structure. Besides, the human bone structure, in contrary to the bovine bone, did not show temperature sensitivity by means of crystallite size increase.

Comparative Analysis of the Properties of Hydroxyapatite Powders Prepared by Different Techniques

The dependence of the physical and chemical properties of hydroxyapatite powder on its preparation technique was determined. Samples produced from biological raw materials by methods of annealing and demineralization of cattle bones were studied. Hydroxyapatite powder surface was studied by scanning electron microscopy, the particle size distribution histograms and the specific surface area values were obtained. The phase compositions of the studied materials were determined by X-ray phase analysis. The preparation technique for ultra-dispersed hydroxyapatite powder with a controlled particle size and Ca/P ratio closest to the stoichiometric one in human bone tissue was determined. It was shown that hydroxyapatite powders produced by cattle bone demineralization method with 1 and 2 M hydrogen chloride aqueous solutions had the best physical and chemical properties in terms of practical application in medicine. Those powders had the smallest particle sizes and the highest specific surface area values.

Сравнительный анализ свойств порошков гидроксиапатита, полученных различными методами

Сравнительный анализ свойств порошков гидроксиапатита, полученных различными методами

Synthesis and Characterization of Hydroxyapatite Powder from Natural Gypsum Rock

This study prepared hydroxyapatite powder that synthesized from natural gypsum rock and find out physicalchemical and cytotoxicity properties. The synthesis realized by reacting natural gypsum powder with 1M of (NH4)2HPO4 solutions using a microwave. Characterizations of natural gypsum powder and hydroxyapatite powder were conducted by XRD, XRF and SEM. In vitro cytotoxicity testings of hydroxyapatite powder were conducted by MTT method using vero cells. XRD patterns of gypsum powder closed to JCPDF 33-0311 (gypsum standard). Characteristics of gypsum powder i.e. contained 41.72% CaO, level of purity 91,6 % and crystal size 7,147 nm. Charateristic of hydroxyapatite powder that synthesized from natural gypsum powder i.e. contained 46.91% CaO and 40.20% P2O5, XRD patern closed to JCPDF 09-432 (hydroxyapatite standard), level of purity 99 % and crystal size 1.243 nm. There were not significantly difference in cytotoxicity properties of hydroxyapatite powder that synthesized from natural gypsum rock and commercial hydroxyapatite powder (p= 0.086). These results indicated hydroxyapatite powder that synthesized from natural gypsum rock possible to be used as bone substitutes.

Effect of Precipitation Method on Properties of Hydroxyapatite Powders

2nd International Congress on Advances in Applied Physics and Materials Science (APMAS) -- APR 26-29, 2012 -- Antalya, TURKEY

Suspension Characteristics and Rheological Properties of Hydroxyapatite Powder in TBA Solvent

Sedimentation bulk density and rheology of TBA-based hydroxyapatite suspensions have been investigated in terms of solid loading and types of additives (gelators, gelators/dispersant, gelators/dispersant/surfactant).

Effect of drying conditions during synthesis on the properties of hydroxyapatite powders

The effect of the drying conditions during the hydroxyapatite (HAp) powder synthesis on the size and microstructure was studied. The starting materials were agitated in water, dried at 60-150 degrees C, and heat-treated at 720 degrees C. The heat-treated HAp powders were crystalline, and their particle sizes decreased with an increase in the drying time, but were independent of the drying temperature. For a 3 day drying period, it was 1.61 microm, and 0.55 microm for 21 days. The surface zeta potential of the HAp powder with a long drying period was more negatively charged than that from the short drying period. The average primary particle sizes of the HAp powders seem to be almost equivalent, and so the drying period may be related to the dispersibility of the primary particles, and may lead to a small HAp particle size.

A Study on The Synthsis of Hydroxyapatite Powders Using Oyster Shells and H3PO4

Hydroxyapatite powders were prepared after heating at <TEX>$1250^{\circ}C$</TEX> by the direct reaction using oyster shells and <TEX>$H_3$</TEX><TEX>$PO_4$</TEX>. Properties of hydroxyapatite powders were investigated as XRF, XRD, DTA, FT-IR, SEM. Only hydroxyapatite was observed in XRD powders which was heated at <TEX>$1250^{\circ}C$</TEX> for 2 hours and there was no remained CaO in that sample. And the results of FT-IR of sample was confirmed hydroxyapatite. Sample was agglomerated together, but needle shape morphology was observed in powders heated at <TEX>$1250^{\circ}C$</TEX>.