Samikannu Kanagesan

Synthesis, Characterization and Effects of Citric Acid and PVA on Magnetic Properties of CoFe2O4

Cobalt ferrite (CoFe2O4) particles were synthesized by sol–gel method using metal nitrates, citric acid (CA) and polyvinyl alcohol (PVA). X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), thermogravimetry/differential scanning calorimetry analysis and vibrating sample magnetometer were used to study the structural, thermal and magnetic properties of the CoFe2O4 powder. XRD results indicate that the resultant particles have crystalline, pure single phase spinel structure. From HR-SEM images, a systematic decrease in particle size is observed with an increase in PVA concentration, along with addition of CA. CA at various concentrations of PVA significantly enhance the magnetic properties of the materials.

Synthesis, Characterization and in Vitro Evaluation of Manganese Ferrite (MnFe2O4) Nanoparticles for Their Biocompatibility with Murine Breast Cancer Cells (4T1)

Manganese ferrite (MnFe2O4) magnetic nanoparticles were successfully prepared by a sol-gel self-combustion technique using iron nitrate and manganese nitrate, followed by calcination at 150 °C for 24 h. Calcined sample was systematically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and vibrational sample magnetometry (VSM) in order to identify the crystalline phase, functional group, morphology, particle size, shape and magnetic behavior. It was observed that the resultant spinal ferrites obtained at low temperature exhibit single phase, nanoparticle size and good magnetic behavior. The study results have revealed the existence of a potent dose dependent cytotoxic effect of MnFe2O4 nanoparticles against 4T1 cell lines at varying concentrations with IC50 values of 210, 198 and 171 μg/mL after 24 h, 48 h and 72 h of incubation, respectively. Cells exposed to higher concentrations of nanoparticles showed a progressive increase of apoptotic and necrotic activity. Below 125 μg/mL concentration the nanoparticles were biocompatible with 4T1 cells.

Parametric optimization of NiFe2O4 nanoparticles synthesized by mechanical alloying

In this study, the Taguchi robust design method is used for optimizing ball milling parameters including milling time, rotation speed and ball to powder weight ratio in the planetary ball milling of nanostructured nickel ferrite powder. In fact, the current work deals with NiFe2O4 nanoparticles mechanochemically synthesized from NiO and Fe2O3 powders. The Taguchi robust design technique of system optimization with the L9 orthogonal array is performed to verify the best experimental levels and contribution percentages (% ρ) of each parameter. Particle size measurement using SEM gives the average particle size value in the range of 59–67 nm. X-ray diffraction using Cu Kα radiation is also carried out to identify the formation of NiFe2O4 single phase. The XRD results suggest that NiFe2O4 with a crystallite size of about 12 nm is present in 30 h activated specimens. Furthermore, based on the results of the Taguchi approach the greatest effect on particle size (42.10 %) is found to be due to rotation speed followed by milling time (37.08 %) while ball to powder weight ratio exhibits the least influence.

Evaluation of Antioxidant and Cytotoxicity Activities of Copper Ferrite (CuFe2O4) and Zinc Ferrite (ZnFe2O4) Nanoparticles Synthesized by Sol-Gel Self-Combustion Method

Spinel copper ferrite (CuFe2O4) and zinc ferrite (ZnFe2O4) nanoparticles were synthesized using a sol-gel self-combustion technique. The structural, functional, morphological and magnetic properties of the samples were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). XRD patterns conform to the copper ferrite and zinc ferrite formation, and the average particle sizes were calculated by using a transmission electron microscope, the measured particle sizes being 56 nm for CuFe2O4 and 68 nm for ZnFe2O4. Both spinel ferrite nanoparticles exhibit ferromagnetic behavior with saturation magnetization of 31 emug−1 for copper ferrite (50.63 Am2/Kg) and 28.8 Am2/Kg for zinc ferrite. Both synthesized ferrite nanoparticles were equally effective in scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radicals. ZnFe2O4 and CuFe2O4 nanoparticles showed 30.57% ± 1.0% and 28.69% ± 1.14% scavenging activity at 125 µg/mL concentrations. In vitro cytotoxicity study revealed higher concentrations (>125 µg/mL) of ZnFe2O4 and CuFe2O4 with increased toxicity against MCF-7 cells, but were found to be non-toxic at lower concentrations suggesting their biocompatibility.

Microstructural and Dielectric Properties of Zr Doped Microwave Sintered Synthesized by Sol-Gel Route

Polycrystalline samples with the chemical formula CaCu3O12 (, 0.02, 0.1, 0.2, 0.5, and 0.1) CCTZO were synthesized from metal nitrate solutions by the sol-gel method, followed by conventional and microwave heat treatments. The X-ray diffraction pattern of powder calcined at 800°C in conventional furnace for 3 h showed formation of a single phase. The crystal structure did not change on doping with zirconium and it remained cubic in the five studied compositions. The surface morphology of samples sintered at 1000°C in microwave furnace for 10 min was observed using a high resolution scanning electron microscope (HR-SEM). The grain sizes were in the range of 250 nm–5 μm for these samples. HRSEM results show that doping with Zr enhanced grain growth or densification. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of Zr. The dielectric characteristics of Zr doped CCTO were studied with an LCR meter in the frequency range of 50 Hz–1 MHz. A very high dielectric constant 21,500 was observed for the sample doped with Zr (0.02 mol%) at 50 Hz.

Low temperature method for synthesis of starch-capped ZnSe nanoparticles and its characterization studies

A facile method for synthesis of monodispersed, starch-capped ZnSe nanoparticles at room temperature is being reported. The nanoparticles exhibited strong quantum confinement effect with respect to the bulk ZnSe. The transmission electron microscopy image indicated that the particles were well dispersed and spherical in shape. The X-ray diffraction analysis showed that the ZnSe nanoparticles were of the wurtzite structure, with average particle diameter of about 3.50 nm. The Fourier transform infrared spectrum confirmed the presence of starch as passivating agent.

Synthesis of Strontium Hexaferrite Using D-Fructose as a Fuel

Strontium hexaferrite (SrFe12O19) powder was synthesized by sol-gel based combustion technique. In this technique, strontium and iron nitrates were used as the source nitrates and D-fructose as the fuel. The phase formation, thermal properties, particle morphology and surface morphology of the sintered pellets were analyzed by X-ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG-DTA) and high-resolution scanning electron microscope (HR-SEM). Crystalline particles obtained by the calcinations of the precursor powder at 900°C, showed the crystalline diffraction pattern with the corresponding major angles, 30.41°, 31.02°, 32.37°, 34.24°, 35.81°, 37.21°, 40.47° and 42.60° respectively. HR-SEM studies have revealed that the structure of calcined particles is a mixed hexagonal and nearly plate like hexagonal, and the surface of the sintered pellets results in hexagonal structure with good magnetic properties.

A Comparative Study of Conventional Sintering with Microwave Sintering of High Dielectric Calcium Copper Titanate Nano Powder Synthesized by Sol-Gel Route

Nano-sized calcium copper titanate (CCTO) powder was derived from sol-gel process. Calcium nitrate, copper nitrate and titanium iso-propoxide were used as raw materials. The XRD results of the powder calcined at 800°C indicated the formation of CCTO phase. AFM studies showed that the particle size of the CCTO powder ranged from 70 to 80 nm. The absorption bands corresponding to vibrations of Ca–O, Cu–O and Ti–O–Ti were observed at 606, 525 and 463 cm–1 using FTIR. The samples sintered at 1040°C showed 96% of theoretical density. The dielectric constant of the sample sintered by conventional pressure less sintering was much higher (23,000 at 1 kHz) than that of microwave sintered samples (1572 at 1 kHz). In microwave sintering the grain boundary thickness decreases so that dielectric constant decreases.

Characterisation of sol-gel method synthesised MgZnFe2O4 nanoparticles and its cytotoxic effects on breast cancer cell line, MDA MB-231 in vitro

In this study, nanocrystalline magnesium zinc ferrite nanoparticles were successfully prepared by a simple sol-gel method using copper nitrate and ferric nitrate as raw materials. The calcined samples were characterised by differential thermal analysis/thermogravimetric analysis, Fourier transform infrared spectroscopy and X-ray diffraction. Transmission electron microscopy revealed that the average particle size of the calcined sample was in a range of 17-41 nm with an average of 29 nm and has spherical size. A cytotoxicity test was performed on human breast cancer cells (MDA MB-231) and (MCF-7) at various concentrations starting from (0 µg/ml) to (800 µg/ml). The sample possessed a mild toxic effect toward MDA MB-231 and MCF-7 after being examined with MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyltetrazolium bromide) assay for up to 72 h of incubation. Higher reduction of cells viability was observed as the concentration of sample was increased in MDA MB-231 cell line than in MCF-7. Therefore, further cytotoxicity tests were performed on MDA MB-231 cell line.

Nanobiomaterial-based delivery of drugs in various cancer therapies

Cancer remains one of the most devastating diseases in the world amid epidemiologic studies suggesting that cancer will be the number one disease in prevalence by 2020. It is described as an abnormal growth of cells triggered by numerous alterations in the expression of crucial genes that leads to the dysregulated balance of cell proliferation and cell death that causes significant morbidity. Using nanotechnology for treating or delivering drugs to the site of cancer cells is acquiring considerable attention. Nanoparticles have also been used to deliver drugs to target tissues and to increase stability against degradation by enzymes. In general, biopolymers, such as protein (silk, collagen, gelatin, β-casein, and albumin), protein-mimicked polypeptides (elastin-like polypeptide), polysaccharides (chitosan, alginate, pullulan, starch, and heparin), lipid-based nanoparticles, polymeric nanoparticles (PLA, PLGA and PCL), and nanotubes (fullerene derivatives), are widely used nowadays to deliver drugs or siRNA to the tumor site. The advantages, limitations, and efficacy of nanoparticles in cancer therapy will be discussed in this chapter also focusing on changes in the biochemical and molecular pathway of cancer cells during nanoparticle-mediated cancer therapy.