Galbanic Acid-Coated Fe3O4 Magnetic Nanoparticles with Enhanced Cytotoxicity to Prostate Cancer Cells.

Galbanic acid is a natural sesquiterpene coumarin compound with different biological activities, particularly cytotoxicity against LNCaP (an androgen-dependent prostate cancer cell line). Galbanic acid induces apoptosis in LNCaP via down-regulation of androgen receptor. However, the poor water-solubility of galbanic acid limits further in vitro and in vivo studies. In this study we present the synthesis of galbanic acid-coated Fe3O4 magnetic nanoparticles and their cytotoxicity evaluation on three prostate cancer cell lines, including PC3 (an androgen-independent cell line), LNCaP, and DU145 (an androgen-independent cell line). The synthesized nanoparticles were characterized by X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, scattering electron microscopy, energy-dispersive X-ray spectroscopy, dynamic light scattering, and vibrating sample magnetometry. Our cytotoxicity evaluation demonstrated that galbanic acid was cytotoxic only against LNCaP cells, while the galbanic acid-coated Fe3O4 nanoparticles showed cytotoxicity on all tested cells, including androgen-dependent and -independent cell lines. This indicates that other mechanisms are involved in the cytotoxicity of galbanic acid in addition to androgen receptor down-regulation. In conclusion, the loading of galbanic acid on the surface of Fe3O4 magnetic nanoparticles turned out to be a successful approach to enhance the solubility and cytotoxicity of this compound.

Sono-synthesis of solar light responsive S-N-C-tri doped TiO2 photo-catalyst under optimized conditions for degradation and mineralization of Diclofenac.

C-N-S-tri doped TiO2 anatase phase was synthesized using a facile, effective and novel sonochemical method at low frequency (20kHz) and at room temperature. Titanium butoxide as the titanium precursor and thiourea as the dopant source were used in the synthesis of the photo-catalyst. The effects of important parameters such as thiourea/Ti molar ratio, ultrasound intensity, sonication time and temperature were studied on the synthesis of tri-doped TiO2. The XPS results confirmed the presence of N, S, and C in the photo-catalyst. The photo-catalytic efficiency of the synthesized catalyst was studied toward the removal of Diclofenac as a model pharmaceutical organic pollutant. The results confirmed that the photo-catalyst synthesized with narrower band gap energy, shorter sonication time and higher ultrasound intensity leads to a rapid removal of Diclofenac. The effect of operational variables on the photo-catalytic activity of C-N-S tri doped TiO2 nanoparticles was studied and optimized using the Taguchi method as a statistical technique. Additionally, the degradation process followed the pseudo-first-order kinetics model and the highest apparent rate constant of 0.0632min-1 achieved in 90min. Chemical oxygen demand (COD) analysis confirmed that the mineralization took place completely (100%) under the optimized conditions in 180min. Different scavengers were applied during the degradation process and active species such as OH and O2- had key roles in the photo-catalytic process.

A novel fluorescent aptasensor for ultrasensitive detection of microcystin-LR based on single-walled carbon nanotubes and dapoxyl.

To assure water safety and protect human health, precise and simple analytical approaches are highly desired to determine low concentrations of microcystin-leucine-arginine (MC-LR), a toxin, in both water and serum samples. Herein, a simple, rapid and accurate aptamer-based fluorescent sensor was used for selective recognition of MC-LR, based on single-walled carbon nanotubes (SWNTs) as immobilizers, dapoxyl as a fluorescent dye, DAP-10 as a specific aptamer for dapoxyl and unmodified MC-LR aptamer (Apt) as a sensing ligand. The sensing method was developed to produce a remarkable fluorescence intensity difference in the absence and presence of MC-LR. Moreover, the Apt was used without any modification. In the absence of MC-LR, the dapoxyl could bind to DAP-10, leading to a strong fluorescence intensity. In the presence of MC-LR, DAP-10 bound to the surface of SWNTs, resulting in a very weak fluorescence intensity. Under optimized conditions, the presented fluorescent analytical approach showed high selectivity toward MC-LR with a limit of detection (LOD) of 138 pM. This new method indicated excellent analytical performance for MC-LR detection in tap water and serum samples with LODs of 135 and 168 pM, respectively.

Epirubicin loaded super paramagnetic iron oxide nanoparticle-aptamer bioconjugate for combined colon cancer therapy and imaging in vivo.

Every year a large number of new cases of colorectal cancer are diagnosed in the world. Application of Epirubicin (Epi) in treatment of cancer has been limited due to its cardiotoxicity. Specific delivery of chemotherapy drugs is an important factor in reducing the side effects of drugs used in chemotherapy. Enhanced permeability, retention effect and magnetic resonance (MR) traceability of super paramagnetic iron oxide nanoparticles (SPION) make them a great candidate in cancer therapy and imaging. In this study, Epirubicin-5TR1 aptamer-SPION tertiary complex was evaluated for the imaging and treatment of murine colon carcinoma cells (C26 cells, target). For cytotoxic studies (MTT assay), C26 and CHO-K1 (Chinese hamster ovary cells, nontarget) cells were treated with either Epi or Epi-Apt-SPION tertiary complex. Internalization was evaluated by flow cytometry. Finally, Apt-SPION bioconjugate was used for imaging of cancer in vivo. Flow cytometric analysis showed that the tertiary complex was internalized effectively to C26 cells, but not to CHO-K1 cells. Cytotoxicity of Epi-Apt-SPION tertiary complex also confirmed internalization data. The complex was less cytotoxic in CHO-K1 cells when compared to Epi alone. No significant change in viability between Epi- and complex-treated C26 cells was observed. Magnetic resonance imaging (MRI) indicated a high level of accumulation of the nano-magnets within the tumor site. In conclusion Epi-Apt-SPION tertiary complex is introduced as an effective system for targeted delivery of Epi to C26 cells. Moreover this complex could efficiently detect tumors when analyzed by MRI and inhibit tumor growth in vivo.

Sono-catalytic degradation and fast mineralization of p-chlorophenol: La(0.7)Sr(0.3)MnO3 as a nano-magnetic green catalyst.

La0.7Sr0.3MnO3 (LSMO) nanoparticles with a perovskite structure were prepared by a combination of ultrasound and co-precipitation method. The synthesized catalyst was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy. The catalytic performance of the catalyst was evaluated for the degradation of 4-chlorophenol in the presence and in the absence of ultrasound. The degradation has been studied at different temperatures, pH, catalyst dosage, and initial concentration of 4-chlorophenol. The results have shown that the degradation efficiency was higher in the presence of ultrasound than its absence under the mild conditions. More than 88% decrease in the concentration and 85% decrease in the TOC for 4-chlorophenol could be achieved in a short time of sonication with respect to the conventional method. This behavior could be attributed to the cavitation process which followed by a high mass transfer on the catalyst with high surface area. These conditions led to facilitate the removal of pollutant from aqueous solution. The results also indicated that the catalyst without recalcination can be used successfully up to five consecutive cycles without any significant loss in activity in the presence and in the absence of ultrasound. In addition, the most important is the magnetic property of the nanoparticles which separated easily from aqueous solution by an external magnetic field.

Sono-synthesis of core-shell nanocrystal (CdS/TiO2) without surfactant.

A core-shell nanocomposite (CdS/TiO(2)) was synthesized at relatively low temperature (70°C) with small particle sizes (~11 nm). First, CdS nanoparticles were prepared by a combination of ultrasound and new micro-emulsion (O/W) without surfactant. Then the synthesized CdS was easily combined with TiO(2) under sonication. The formation of uniform surface layer of TiO(2) with depths of 0.75-1.1 nm on the CdS led to an increase of particle size. Ultrasonic irradiation can control the hydrolysis and condensation of titanium tetra-isopropoxide (TTIP) and the formation of TiO(2) shell around the CdS core. This technique avoids some of the problems that exist in conventional microemulsion synthesis such as the presence of different additives and calcinations. It was found that nanocomposite particles extend the optical absorption spectrum into the visible region in comparison with pure TiO(2) and pure CdS. In addition, a larger depth of TiO(2) led to a red-shift of the absorption band in nanocomposite. The characterization of nanocomposites has been studied by HRTEM, TEM, XRD, EDAX, BET and, UV-vis.

Exceptional catalytic efficiency in mineralization of the reactive textile azo dye (RB5) by a combination of ultrasound and core-shell nanoparticles (CdS/TiO2).

A novel composite with a core-shell structure (CdS/TiO(2)) was prepared through the combination of microemulsion and ultrasound (20 kHz). The degradation of reactive black 5 (RB5) was carried out in aqueous solution in a series of experiments by CdS/TiO(2) nanoparticles. This composite with mole ratio of 1/6 has shown an exceptional sonocatalytic activity in comparison to the pure nanoparticles of TiO(2) and CdS. A significant decrease in the concentration of RB5 (≈ 94%) was observed in 3 min sonication of the solution containing the core-shell nanocomposite. While at the same time, the concentration was reduced to 4% under sonication without nanocomposite and 50% under UV light with nanocomposite. The increased catalytic activity of nanocomposite in the presence of ultrasound is due to the enhancement of mass transfer, cleaning and sweeping the surface of catalyst, and preventing the aggregation of particles. In addition, the presence of CdS nanoparticles in the composite acts as photosensitizer which not only extends the spectral response to the visible region but also reduces the charge recombination. The selected combined method (sonocatalysis) was able to decolorize and oxidize simultaneously the organic dye with a complete mineralization into SO(4)(2-) and NO(3)(-) ions.

Fast and easy synthesis of core-shell nanocrystal (CdS/TiO2) at low temperature by micro-emulsion under ultrasound.

CdS nanoparticles were easily combined with TiO(2) through a reaction in micro-emulsion by means of ultrasonic irradiation. The formation of a uniform layer of TiO(2) on the CdS led to an increase of the size of nanoparticles. This is due to the appearance of a core-shell structure between the two combined semiconductors with a strong interface between them. TiO(2) shell depths were in the range of 1.4-2.3 nm. Nano-scale depths of TiO(2) layers on the CdS can be easily controlled by adjusting the concentration of TTIP (titanium tetra-isopropoxide). Important variables such as the preparation method, molar ratio of the reactants, and time of sonication were investigated. Ultrasonic irradiation can control the hydrolysis and condensation of TTIP and the formation of a gradient TiO(2) shell around the CdS core. The nanoparticles were characterized by X-ray diffraction (XRD), UV-visible spectroscopy, energy dispersed analysis of X-ray (EDAX), HRTEM, SEM, and surface area measurements (BET).

Micro-emulsion under ultrasound facilitates the fast synthesis of quantum dots of CdS at low temperature.

Semiconductor nano-particles of CdS (about 2 nm) with a hexagonal phase have been prepared at a relatively low temperature (60°C) and short time in micro-emulsion (O/W) under ultrasound. This study presents the effects of ultrasonic irradiation on the formation of CdS nano-particles in micro-emulsion and compares the results with samples prepared without sonication. The nano-particles have been characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), energy dispersed analysis of X-ray (EDAX), UV-visible spectroscopy, and surface area measurements (BET). The effect of some important factors such as sonication time, intensity of ultrasound, temperature, and oil fraction was studied on the prepared nano-particles. The particle size can be controlled by applying the ultrasonic waves on the micro-emulsion under proper conditions. It has been postulated that bubble collapse generates high temperature and many nucleation sites which lead to the uniform spherical particles with small size and fast transition phase. Further evidence was obtained by UV-visible absorption and a photoluminescence spectrum. The study of optical properties reveals that the band-gap of the CdS nano-particle decreases with increase of sonication time and reach an approximate constant value. It was also observed that nano-particles grew faster at the beginning of sonication and then reached an almost constant value. The growth of nano-particles at different intervals during sonication was followed by UV-visible spectroscopy.

Ultrasound with low intensity assisted the synthesis of nanocrystalline TiO2 without calcination.

A novel method has been developed for the preparation of nano-sized TiO(2) with anatase phase. Nanoparticles with diameter about 6 nm were prepared at a relatively low temperature (75 degrees C) and short time. The synthesis was carried out by the hydrolysis of titanium tetra-isopropoxide (TTIP) in the presence of water, ethanol, and dispersant under ultrasonic irradiation (500 kHz) at low intensity. The results show that variables such as water/ethanol ratio, irradiation time, and temperature have a great influence on the particle size and crystalline phases of TiO(2) nanoparticles. Characterization of the product was carried out by different techniques such as powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and UV-vis spectroscopy.

Ultrasound facilitates and improves removal of Cd(II) from aqueous solution by the discarded tire rubber.

Some of the heavy metal ions such as cadmium are toxic and represent as hazardous pollutants due to their persistence in the environment. In this study the ground discarded tire rubber was used for the sorption of cadmium from aqueous solution. The batch sorption tests were conducted to investigate the sorption of Cd(II) by discarded tire rubber in the presence and absence of ultrasound. To assess the capability of sorbent, research parameters such as ultrasonic waves, solution temperature, particle size of ground tire and others were investigated. The experimental data were fitted in Langmuir model better than Freundlich one. Therefore, the former model was applied to the sorption equilibrium in order to determine the maximum metal sorption capacity in the presence and absence of ultrasound. The Langmuir constants were also obtained from the isotherms under different conditions. In the presence of ultrasound the tire rubber was a more efficient sorbent for this pollutant than its absence. According to the results, the internal porous and film diffusions were both effective in the sorption process. The porous and film diffusion coefficients of the ground tire rubber were, respectively, about 1.8 and 2.7 times more in the presence of ultrasound than its absence. The effect of ultrasound on the sorption process could be explained by the thermal and non-thermal properties of ultrasonic field.

Combination of ultrasound and discarded tire rubber: removal of Cr(III) from aqueous solution.

Ground discarded tire rubber is an interesting and inexpensive medium for the sorption of toxic metals, including chromium, from water. The batch sorption tests were conducted to investigate the sorption capacity of Cr(III) from aqueous solution by ground tire in the presence and absence of ultrasound. The research parameters included ultrasonic waves, solution temperature, aqueous chromium concentration, particle size of the ground tire, contact time, and others. The Langmuir model was applied to the sorption equilibrium to determine the maximum metal sorption capacity in the presence and absence of ultrasound. The Langmuir constants were also obtained from the isotherms under different conditions. The results indicated that the tire rubber was a more efficient sorbent for the removal of chromium in the presence of ultrasound. Because there are several stages in the sorption process, it is important to find out which step or steps control the rate of sorption. According to the results, the internal porous diffusion is the rate-controlling step. The diffusion coefficient of Cr(III) in ground tire rubber in the presence of ultrasound was about two times greater than that in the absence of ultrasound. The effect of ultrasound on the sorption process could be explained by the thermal and nonthermal properties of acoustic cavitation.