Liposome-Fe3 O4-Doxorubicin Mediated Treatment of Melanoma Tumors.

Purpose: Magnetic hyperthermia is a treatment method based on eddy currents, hysteresis, and relaxation mechanisms of magnetic nanoparticles (MNPs). MNPs such as Fe3 O4 have the ability to generate heat under an alternating magnetic field. Heat sensitive liposomes (Lip) convert from lipid layer to liquid layer through heat generated by MNPs and can release drugs. Methods: In this study, different groups of doxorubicin (DOX), MNPs and liposomes were evaluated. The MNPs were synthesized by co-precipitation method. The MNPs, DOX and a combination of MNPs and DOX were efficiently loaded into the liposomes using the evaporator rotary technique. Magnetic properties, microstructure, specific absorption rate (SAR), zeta potential, loading percentage of the MNPs and DOX concentration in liposomes, in vitro drug release of liposomes were studied. Finally, the necrosis percentage of cancer cells in C57BL/6J mice bearing melanoma tumors was assessed for all groups. Results: The loading percentages of MNPs and concentration of DOX in the liposomes were 18.52 and 65% respectively. The Lip-DOX-MNPs at the buffer citrate solution, showed highly SAR as the solution temperature reached 42°C in 5 minutes. The release of DOX occurred in a pH-dependent manner. The volume of tumor in the therapeutic groups containing the MNPs significantly decreased compared to the others. Numerical analysis showed that the tumor volume in mice receiving Lip-MNPs-DOX was 9.29% that of the control and a histological examination of the tumor section showed 70% necrosis. Conclusion: The Lip-DOX-MNPs could be effective agents which reduce malignant skin tumors growth and increase cancer cell necrosis.

Effect of hydrophilic silica and dual coagulation bath on structural and mechanical properties of PVDF membrane for membrane distillation.

The water scarcity threatens environmental health and human development. Membrane distillation (MD) is one of the most applicable processes for purifying water using a hydrophobic membrane. In this study, the synergetic effect of SiO2 nanoparticles as well as employing the dual coagulation bath on physical and mechanical properties of Polyvinylidene Fluoride (PVDF) flat-sheet membranes produced by dry-wet phase inversion (DIPS) technique has been investigated. The results of microstructural analysis using Scanning Electron Microscope (SEM) demonstrated that by adding nanoparticles while the pore size decreased noticeably, the percentage of porosity significantly increased. Also, it has been revealed that by utilizing isopropanol as the first coagulation bath the finger-like macro-voids became smaller in size, and the share of sponge-like structures rose remarkably. The membrane performance was tested by Vacuum Membrane Distillation (VMD) for measuring the flux and Liquid Entry Pressure (LEPw) laboratory setup. It can be seen that by increasing the content of SiO2 nanoparticles to 6 wt.% while the LEPw approximately halved, the flux soared to about 10000 g/m2h. Moreover, mechanical testing showed that although the tensile strength of nanocomposite samples fabricated in isopropanol dual coagulation bath was improved by up to 66%, their ductility slightly declined. Furthermore, the hydrophobicity of each membrane was examined via contact angle measurements. Finally, it was found that all membranes completely rejected the NaCl in rejection test. Graphical abstract.

Designing, constructing and testing of a new generation of sound barriers.

PURPOSE: Nowadays, noise pollution is considered a major environmental problem which has affected the health and comfort of millions of people around the world. Solving the mentioned problems need to design a new generation of acoustic barriers. Acoustics experts believe that stopping and absorbing the low-frequency sound is difficult. The aims of this study were to remove the harmful frequency in industries and cities. This study concentrates on the reduction of the noise level and increasing the mass law and resonance at low frequencies. METHODS: Sound measurement and frequency analysis did to fix the harmful frequency in the Shiraz city and in the Shiraz Gas Power Plant. COMSOL 5.3a software used for simulation. Suitable material chose for the manufacture of the sound barrier through the Cambridge engineering selection software 2013. The meta-material sound barrier made and tested in the acoustic room and in the free space. Results analyzed and optimized by Design of Experiment (DOE) and Response Surface Methodology (RSM) software. Mini Tab. 18.1 software used for Statistical Calculations. New sound barriers manufactured with adding new strategies to previous studies to improve the performance of meta-materials like beautification inspired from the flowers of nature and increasing of resonance in internal pipes. RESULTS: Three mechanisms used in this scatterer model which included, resonance phenomenon, Band Gap (BG) without absorption mechanism and inner-fractal-like structure. Our technique showed an advantage to reduce at frequencies below 100 Hz without adsorbent usage. The results showed that reduced noise exposures about 17.8 dB at frequency 50 Hz, about 9.1 dB within the range of 250 Hz according to EN 1793-2 standard (Lab Test for Airborne Sound Insulation). The sound barrier reported in this work provides the best and updated solution in the field of noise control. CONCLUSIONS: A novel generation of sound barriers introduced. We called this structure Interior Quasi-Fractal Sonic Crystal Acoustic Barrier (IQFSCAB). In this study, several different gaps used to remove various frequencies. It could be concluded that the outcomes of the meta-material models based on the Sonic Crystal (SC) could be used for the purpose of noise control system and could be helpful for decision-makers on the noise control legislations. Graphical abstractInteraction of waves with noise barriers and wave propagation inside periodic media is a hot topic in many branches of science and technology. The acoustic metamaterial can create green environments by reducing the low frequencies of industrial noise or traffic jam. New barrier have added a number of new strategies to previous studies in order to improve the performance of meta-materials. Our technique shows a clear advantage over to absorb at frequencies below 100 Hz without adsorbent usage. Innovative use of several different gaps and diameters for to remove various frequencies was done in this study. We called this structure IQFSACB due to fractal like interior pipes as those seen in some of the flowers in nature.

Optimization of toluene removal over W-doped TiO2 nano-photocatalyst under visible light irradiation.

This study outlines the optimization of photocatalytic degradation of toluene by W-doped TiO2 nanoparticles under visible light irradiation. Experiments were carried out based on the central composite design (CCD) methodology. W-TiO2 nanoparticles were synthesized with various tungsten contents at different calcination temperatures by the sol-gel method. The nanoparticles' characteristics were determined using appropriate techniques such as field emission scanning electron microscopy, particle size analysis, X-ray diffraction and energy-dispersive spectroscopy. The effect of different operational conditions of coating mass, initial toluene concentration, and exposure time on the toluene removal efficiency was investigated. Result showed that tungsten has a fundamental role in improving the photocatalytic activity of TiO2 under visible light, as well as improving its photoactivity under UV irradiation by decreasing the rate of electron/hole charge recombination. Analysis of the obtained data on toluene removal with a CCD approach illustrated that the quadratic model can effectively predict the toluene removal with coefficient of determination of R2 = 0.862. Tungsten content and exposure time affect the toluene removal efficiency more than other factors. Results showed that maximum toluene removal efficiency slightly depends on the initial concentration of toluene. At the initial toluene concentration of 4000 ppm, the optimum values of the calcination temperature, tungsten content, coating mass, and exposure time were 500°C, 0.52 wt%, 11.7 g/m2, and 8 h, respectively, with 59% removal of toluene.

Effect of Magnetic Fluid Hyperthermia on Implanted Melanoma in Mouse Models.

BACKGROUND: Nowadays, magnetic nanoparticles (MNPs) have received much attention because of their enormous potentials in many fields such as magnetic fluid hyperthermia (MFH). The goal of hyperthermia is to increase the temperature of malignant cells to destroy them without any lethal effect on normal tissues. To investigate the effectiveness of cancer therapy by magnetic fluid hyperthermia, Fe0.5Zn0.5Fe2O4 nanoparticles (FNPs) were used to undergo external magnetic field (f=515 kHz, H=100 G) in mice bearing implanted tumor. METHODS: FNPs were synthesized via precipitation and characterized using transmission electron microscopy (TEM), vibrating sample magnetometer, and Fourier transform infrared. For in vivo study, the mice bearing implanted tumor were divided into four groups (two mice per group), namely, control group, AMF group, MNPs group, and MNPs&AMF group. After 24 hours, the mice were sacrificed and each tumor specimen was prepared for histological analyses. The necrotic surface area was estimated by using graticule (Olympus, Japan) on tumor slides. RESULTS: The mean diameter of FNPs was estimated around 9 nm by TEM image and M versus H curve indicates that this particle is among superparamagnetic materials. According to histological analyses, no significant difference in necrosis extent was observed among the four groups. CONCLUSION: FNPs are biocompatible and have a good size for biomedical applications. However, for MFH approach, larger diameters especially in the range of ferromagnetic particles due to hysteresis loss can induce efficient heat in the target region.

Cationic albumin-conjugated magnetite nanoparticles, novel candidate for hyperthermia cancer therapy.

We developed a novel hyperthermia material for cancer therapy, cationic albumin-conjugated magnetite nanoparticles (MNPs), which absorb the energy of an alternating magnetic field and convert it into heat. MNPs of about 10 nm were synthesised through co-precipitation, and citric acid was used to stabilise the MNP suspension. Then albumin was cationised by replacing anionic side chain groups with cationic groups. The surface modification of the MNPs was provided by cationic albumin, which was covalently conjugated to carboxylic acid functions located at the distal end of the MNPs' surface by carbodiimide chemistry. Finally, we obtained stable superparamagnetic suspensions with particle sizes of 140 nm and saturation magnetisation of 67 emu/g, which do not have the disadvantage of eventual desorption of physical attachment. We also analysed the potential of these particles for magnetic fluid hyperthermia by determination of the specific absorption rate at a constant frequency of 215 kHz; the temperature increase of the particles was 30.8 °C. This study experimentally demonstrates the high efficiency of these nano-heaters.

Add/drop filter using in-plane slanted gratings in azo polymers.

We have fabricated in-plane slanted gratings on azo-functionalized polymeric films using a fast, direct-writing method. By properly adjusting the resonance, these gratings can be used as 90 degrees integrated reflectors and add/drop filters in the plane of the film. We have produced an attenuation of 14.8 dB at 1560.2 nm with a FWHM of 6.47 nm. Also, a signal of 1548 nm wavelength was added to the output from a different direction. Any light shifted from the resonance will pass through the filter undisturbed.