Influence of wet chemical processing conditions on structure and properties of magnetic hydroxyapatite nanocomposites (original) (raw)
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Simplified preparation and characterization of magnetic hydroxyapatite-based nanocomposites
Materials Science and Engineering: C, 2017
Authors aimed to provide a magnetic responsiveness to bone-mimicking nano-hydroxyapatite (n-HA). For this purpose, dextran-grafted iron oxide nanoarchitectures (DM) were synthesized by a green friendly and scalable alkaline co-precipitation method at room temperature and used to functionalize n-HA crystals. Different amounts of DM hybrid structures were added into the nanocomposites (DM/n-HA 1:1, 2:1 and 3:1weight ratio) which were investigated through extensive physicochemical (XRD, ICP, TGA and Zetapotential), microstructural (TEM and DLS), magnetic (VSM) and biological analyses (MTT proliferation assay). X-ray diffraction patterns have confirmed the n-HA formation in the presence of DM as a co-reagent. Furthermore, the addition of DM during the synthesis does not affect the primary crystallite domains of DM/n-HA nanocomposites. DM/n-HAs have shown a rising of the magnetic moment values by increasing DM content up to 2:1 ratio. However, the magnetic moment value recorded in the DM/n-HA 3:1 do not further increases showing a saturation behavior. The cytocompatibility of the DM/n-HA was evaluated with respect to the MG63 osteoblast-like cell line. Proliferation assays revealed that viability, carried out in the absence of external magnetic field, was not affected by the amount of DM employed. Interestingly, assays also suggested that the DM/n-HA nanocomposites exhibit a possible shielding effect with respect to the antiproliferative activity induced by the DM particles alone.
Magnetic hydroxyapatite nanocomposites: The advances from synthesis to biomedical applications
Materials & Design, 2021
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In situ synthesis of hydroxyapatite nanocomposites using iron oxide nanofluids at ambient conditions
This paper describes a simple method for the room temperature synthesis of magnetite/hydroxyapatite composite nanocomposites using ferrofluids. The in situ synthesis of magnetic–hydroxyapatite results in a homogenous distribution of the two phases as seen both in transmission electron micrographs and assembled to a micron range in the confocal micrographs. The selected area diffraction pattern analysis shows the presence of both phases of iron oxide and hydroxyapatite. To the dialyzed ferrofluid, the constituents of hydroxyapatite synthesis was added, the presence of the superparamagnetic iron oxide particles imparts directionality to the hydroxyapatite crystal growth. Electron probe microanalysis confirms the coexistence of both iron and calcium atoms. Vibrating Sample magnetometer data shows magnetization three times more than the parent ferrofluid, the local concentration of iron oxide nanoparticles affects the strength of dipolar interparticle interactions changing the energy barrier for determining the collective magnetic behavior of the sample. The limitations inherent to the use of external magnetic fields which can be circumvented by the introduction of internal magnets located in the proximity of the target by a minimal surgery or by using a superparamag-netic scaffold under the influence of externally applied magnetic field inspires us to increase the magnetization of our samples. The composite in addition shows anti-bacterial properties against the two gram (-ve) bacteria tested. This work is significant as magnetite–hydroxyapatite composites are attracting a lot of attention as adsorbents, catalysts, hyperthermia agents and even as regenerative medicine.
Structural characterization of nanostructured hydroxyapatite–iron oxide composites
Ceramics International, 2014
Nanostructured hydroxyapatite (HA)-iron oxide composites obtained by a wet-chemical method through co-precipitation were investigated with respect to the changes induced in the samples structure by progressive addition of iron, by thermal treatments carried out at 450 1C, 550 1C and 700 1C, and by incubation in simulated body fluid. The structural changes were analyzed by X-ray diffraction (XRD), electron paramagnetic resonance (EPR) and magic angle spinning nuclear magnetic resonance (MAS-NMR). After heat treatments, crystalline HA was developed in all samples, even in larger amount in those with iron, showing that iron acts as a catalyzer for HA development. The MAS-NMR results show as well that only a part of the iron atoms are uniformly incorporated in the HA structure by replacing calcium. EPR results support that an important part of iron atoms are disposed in regions rich in iron that behave like superparamagnetic or magnetic particles distributed in HA matrix. The analyses carried out on 550 1C treated samples, after three days of immersion in SBF, point out a decrease of HA crystallite size and the appearance on particles surface of a new amorphous calcium phosphate layer.
Synthesis of Superparamagnetic Hydroxyapatite Core-Shell Nanostructure by a Rapid Sol-Gel Route
Magnetic transportation of therapeutic agents to the infected site in the body promises a superb platform for cancer treatment. To increase the safety profile and to stay clear from the agglomeration issue, core shell structure of magnetite-hydroxyapatite (Fe3O4-HAp) nanoparticles was developed. Fe3O4 as the core was synthesised by co-precipitation method which then coated with HAp layer through the sol-gel technique to maintain its high crystalline property. Optimum process parameters were applied during the fabrication process to yield small nanocomposites. The results show that HAp retained its phase purity and molecular structure even with the addition of Fe3O4 as analysed by XRD and FTIR. The FESEM and TEM micrographs show a magnificent monodispersed distribution of functionalised Fe3O4-HAp nanoparticles with the size of around 36 nm. EDXRF result confirmed the Ca/P ratio of 1.63, close to the value of main inorganic material of human bones (HAp) and possessed the superparamagnetic properties with saturation magnetisation of 23.274 emu/g as displayed by VSM curves. Thus, the dual affinity of the magnetic Fe3O4 and excellent biocompatibility HAp offer a synergetic effect as the drug or gene delivery vehicle to stealthy localize in infection site.
Current Nanoscience, 2011
In this study, synthetic hydroxyapatite nanoparticles (Hap NPs) were rendered magnetic by treatment with iron ions using a wet-chemical process. The magnetized Hap (mHap) NPs were fabricated by the addition of iron precursor in various ratios of Fe:Ca (XFe/ Ca). The physicochemical properties of mHap NPs were evaluated respectively, by X-ray diffraction (XRD) for the crystal structure, Fourier transform infrared (FTIR) spectroscopy for functional groups detection, Energy-Dispersive X-ray Spectroscopy (EDS) for composition analysis , transmission electron microscopy (TEM) for particle morphology characterization, and superconducting quantum interference device (SQUID) for magnetization property. The size distribution of mHap randomly in rod and needle-like shape was in average 80 to 120 nm. We found that the mHap was the result of the hetero-epitaxial growth of magnetite on the Hap crystallites. The magnetic NPs with sphere shape less than 10 nm in diameters were tightly surrounded on Hap crystallites and possessed superparamagnetic property. The magnetization of all groups of mHap NPs increased with the increasing of XFe/ Ca and with no toxic effect to cultured cells. In brief, mHap NPs demonstrated suitable physicochemical properties and good biocompatibility, suggesting that these NPs have potential applications as new biodegradable MRI contrast agent in medicine.
Journal of the Korean Physical Society, 2019
Hydroxyapatite, which has been widely used in the medical field in the last couple of years, is a superior biomaterial due to its biocompatibility and nontoxicity. Hydroxyapatite requires highly magnetic materials to perform maximally in specific medical fields. In this study, hydroxyapatite/magnetite composites mainly composed of limestone and natural iron sand were synthesized through a coprecipitation method, and composites having different hydroxyapatite-to-magnetite mass ratios were compared. The crystal structure, particle size, fractal dimension, morphology, functional group, and energy gap were characterized using X-ray diffraction (XRD), synchrotron X-ray scattering (SAXS), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and ultraviolent-visible (UV-Vis) spectroscopy. The research results showed that the hydroxyapatite and magnetite phases had a hexagonal structure and cubic structure, respectively. In general, from the FTIR data analysis, the hydroxyapatite and magnetite particles were identified from the functional groups of phosphate, iron-oxygen, carbonate, and hydroxyl. Moreover, depending on particle size, the samples consisting of 3.7-nm primary particles formed a cluster with a massive three-dimensional structure. Meanwhile, the energy gap showed various values ranging between 3.25 and 3.86 eV.
Magnetochemistry
In this work, we report on the fabrication of nanocomposites based on superparamagnetic iron oxide nanoparticles (SPIONs) in combination with hydroxyapatite (HAp) as a platform for drug delivery and magnetic hyperthermia application. First, the influence of experimental conditions such as co-precipitant, bath temperature, and pH on the morphology and magnetic properties of SPIONs was investigated. Then, the superparamagnetic particles were coated with the hydroxyapatite layer for further loading of anticancer drugs, determining the optimal thickness of the HAp shell. The composite was fabricated by the wet chemical process and was characterized by optimizing the experimental conditions of the wiring synthesis to obtain the superparamagnetic spherical material with a high HAp loading as a platform for drug uptake. SEM and TEM studies confirmed the round shape of the magnetic core up to 15 nm in size with a well-defined HAp shell. After checking the material’s superparamagnetic proper...
A novel preparation of magnetic hydroxyapatite nanotubes
We report here the novel preparation of magnetic hydroxyapatite nanotubes (MHAnt). Poly(caprolactone) (PCL)-magnetite nanoparticles (MNPs) composite nanofiber was used as a template for the MHAnt. The surface of the composite nanofiber was activated in an alkaline solution and then an apatite mineral phase was deposited through a series of solution-mediated processes. After heat-treatment at 500°C, a hollow tube of HA-MNPs was created in which HA formed an outer shell and most of the MNPs lined the inner shell surface. The inner shell size was about 650 nm and the shell thickness was about 137 nm. The developed MHAnt showed a saturation magnetization of 27.20 emu/g, exhibiting a ferromagnetic property. The newly developed MHAnt may be useful in biomedical applications such as hyperthermia treatment of bone cancer.
Aqueous ferrofluids as templates for magnetic hydroxyapatite nanocomposites
Journal of Materials Science-materials in Medicine, 2010
Poly (vinyl) alcohol stabilized aqueous ferrofluids (PVA-ff) were used as nanotemplates for the crystallization of calcium hydroxyapatite (HAp). Four sets of PVA-ff-HAp nanocomposites were synthesized using 20, 40, 60 and 80 ml of PVA-ff for the same initial constituents of HAp. Various physico-chemical analyses suggest that the HAp lattice structure accommodates PVA-ff to a certain extent, beyond which the magnetic intra-molecular interactions predominate and PVA-ff starts to be pushed out of the HAp matrix. The in situ incorporation of PVA-ff during HAp synthesis results in a novel magnetic biomaterial with potential applications as targeted delivery vehicles.