Dielectric properties of Fe doped hydroxyapatite prepared by sol–gel method

Kayğili, Ömer; Dorozhkin, Sergey V.; Ateş, Tankut; Al-Ghamdi, Ahmed A.; Yakuphanoğlu, F.

doi:10.1016/j.ceramint.2014.02.009

Cited by 120 publications

(50 citation statements)

References 34 publications

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“…Mn was further reported to be beneficial for bone regeneration due to its induction of osteoblast proliferation and the propensity to positively influence the osteoblast metabolic activity 17 . Incorporation of Fe into HAp crystal structure to impart magnetic properties to the material 18 and the resulting promotion of bone remodeling and tissue regeneration have also been reported 19 . Further, Fe-doped HAp has also been exploited for its superparamagnetic nature 20 as well as to deliver drugs 21 and boost the osteoblastic activity 22 , thus positively affecting bone regeneration.…”

Section: Introductionmentioning

confidence: 94%

One ion to rule them all: the combined antibacterial, osteoinductive and anticancer properties of selenite-incorporated hydroxyapatite

Uskoković

Iyer

2017

J. Mater. Chem. B

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Although hydroxyapatite (HAp) has been doped with dozens of different ions, the quest for an ion imparting a combination of properties conducive to bone healing is still ongoing. Because of its protean potency and the similarity in size and shape to the phosphate tetrahedron, selenite ion presents a natural ionic substitute in HAp. The incorporation of selenite into synthetic HAp using two different methods – co-precipitation and ion-exchange sorption - was studied for its effect on crystal properties and on a triad of biological responses: antibacterial, anticancer and osteoinductive. Co-precipitation yielded HAp with higher selenite contents than sorption and the stoichiometry of HAp richest in selenite was represented as Ca9.75(PO4)5.75(SeO3)0.25(OH)1.75. Crystallinity of HAp decreased in direct proportion with the amount of selenite incorporated. Because of their lower selenite content, HAp powders prepared by ion-exchange exhibited a consistently higher crystallinity compared to the co-precipitated ones. Annealing partially recovered the crystallinity, yet the difference in crystallinity between powders prepared by co-precipitation and by ion-exchange remained, suggesting that the amorphization is mainly due to structural incorporation of selenite, not its effect on the crystal growth kinetics. The addition of selenite changed the morphology of HAp nanoparticles from acicular to rounded and affected the crystal lattice parameters in different ways depending on whether the powders were annealed or not. As for the annealed powders, the incorporation of selenite contracted the lattice in both a and c crystallographic directions. In the agar diffusion assay, the effectiveness of HAp was more dependent on the presence or absence of selenite in it than on its concentration and was highest against E. coli and S. aureus, moderately high against S. enteritidis and ineffective against P. aeruginosa. In liquid inoculation tests, on the other hand, the antibacterial activity of HAp was directly proportional to the amount of selenite contained in it. The viability of K7M2 osteosarcoma cells decreased in direct proportion with the amount of selenite in HAp and was significantly different from the untreated control and from pure HAp at contents equal to or higher than 1.9 wt.%. In contrast, no reduction was observed in the viability of primary fibroblasts treated with HAp incorporating different amounts of selenite ions, suggesting their potentially selective anticancer activity: lethal for the cancer cells and harmless for the healthy cells. Finally, mRNA expression of bone gamma-carboxyglutamate protein (BGLAP3) was higher in differentiated MC3T3-E1 osteoblastic cells treated with selenite-incorporated HAp particles than in cells treated with pure HAp. The osteoinductive effect was due to an overall higher metabolic activity of cells treated with the particles and not due to increased proliferation. In such a way, a triad of antibacterial, osteoinductive and anticancer activities was attributed to selenite-incorporated ...

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Section: Introductionmentioning

confidence: 94%

One ion to rule them all: the combined antibacterial, osteoinductive and anticancer properties of selenite-incorporated hydroxyapatite

Uskoković

Iyer

2017

J. Mater. Chem. B

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“…This indicates that there is an inversely proportional relation between the relative permittivity and crystallite size. The influence of various anions changes the relative permittivity and in turn, the crystallite size [38,39]. The change in ε′ values are also represented in Table 3.…”

Section: Dielectric and Ac Conductivity Of The Samplesmentioning

confidence: 99%

Effect of anions on the structural, morphological and dielectric properties of hydrothermally synthesized hydroxyapatite nanoparticles

Sundarabharathi¹,

Ponnamma

Parangusan

et al. 2019

SN Appl. Sci.

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Synthetic nano hydroxyapatites (HA) have been considered as potential biomaterials for bone tissue engineering applications because of its excellent biological properties. The present work deals with the synthesis of HA nanoparticles from different anion source materials via autoclave assisted hydrothermal method. All the prepared HA nanoparticles were characterized by X-ray diffraction (XRD), Fourier transformation infrared spectra, field emission scanning electron microscopy, energy dispersive spectra and high resolution transmission electron microscopy. The XRD patterns reveal the pure and hexagonal phase structure with smaller crystallite size for HA obtained from various calcium salt precursors. HA particles prepared from nitrate precursors show spherical morphology with 32 nm grain size whereas those derived from the acetate, chloride and egg shell precursors respectively show needle-like, irregular and oval morphology. The effect of different anions on the dielectric properties and alternating conductivity of HA is investigated, as a polarized surface can trigger biological reactions. For the particles obtained from nitrate, acetate, chloride and egg shell precursors respectively give dielectric constant (εʹ) values of 9.96, 13.22, 9.92 and 10.86 at 5 MHz. The εʹ and dielectric loss (εʹʹ) values for the HA nanoparticles decrease with increase in the applied frequency as well. The alternating current conductivity values confirm that the as-synthesized HA samples exhibit insulating behavior. In short this article provides the various applicability of HA particles in optoelectronics and drug delivery.

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“…HAp has been synthesized by several methods including sol-gel, spray pyrolysis, combustion, hydrothermal, microwave, precipitation and extraction from natural resources, and the structural properties of HAp can be changed and controlled by the preparation technique [6][7][8][9][10][11]. Furthermore, the doping process of HAp with different elements such as Mg, Sr, Zn, Ce, Ag, Fe and Si has been used to improve the characteristic properties of HAp [12][13][14][15][16][17][18]. Strontium (Sr), as a trace element in human body, improves bone strength, bone healing and microarchitecture [19].…”

Section: Introductionmentioning

confidence: 99%

Strontium substituted hydroxyapatites: Synthesis and determination of their structural properties, in vitro and in vivo performance

Kayğili

Keser

Köm

et al. 2015

Materials Science and Engineering: C

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Dielectric properties of Fe doped hydroxyapatite prepared by sol–gel method

Cited by 120 publications

References 34 publications

One ion to rule them all: the combined antibacterial, osteoinductive and anticancer properties of selenite-incorporated hydroxyapatite

One ion to rule them all: the combined antibacterial, osteoinductive and anticancer properties of selenite-incorporated hydroxyapatite

Effect of anions on the structural, morphological and dielectric properties of hydrothermally synthesized hydroxyapatite nanoparticles

Strontium substituted hydroxyapatites: Synthesis and determination of their structural properties, in vitro and in vivo performance

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