A zinc ferrite nanodrug carrier for delivery of docetaxel: synthesis, characterization, and in vitro tests on C6 glioma cells.

AIM: Docetaxel (DTX) loaded bio-compatible PLGA-PEG encapsulated zinc ferrite nanoparticles (ZFNP) formulation was developed and evaluated against C6 glioma cells. METHODS: The ZFNP were characterised using XRD, FE-SEM, TEM, etc. A series of drug formulations were fabricated by conjugating hydrothermally synthesised ZFNP with DTX in a PLGA-PEG matrix and optimised for drug loading. FTIR and DLS analysis of the formulation along with in vitro drug release, cytotoxicity, cellular uptake, and haemolytic effect were evaluated. RESULTS: Spherical, monodisperse, crystalline ZFNP with an average size of ∼28 nm were formed. The optimised formulation showed a hydrodynamic diameter of ∼147 nm, a surface charge of -34.8 mV, a drug loading of 6.9% (w/w) with prolonged drug release properties, and higher toxicity in C6 glioma cells compared to free DTX along with good internalisation and negligible haemolysis. CONCLUSION: The results indicate ZFNP could be effectively used as nanodrug carrier for delivery of docetaxel to glioma cells.

Anticancer potential of docetaxel-loaded cobalt ferrite nanocarrier: an in vitro study on MCF-7 and MDA-MB-231 cell lines.

AIM: To develop a biocompatible cobalt ferrite (CF-NP) nanodrug formulation using oleic acid and poly (d,l-lactide-co-glycolic) acid (PLGA) for the delivery of docetaxel (DTX) specifically to breast cancer cells. METHODS: The CF-NP were synthesised by hydrothermal method and conjugated with DTX in a PLGA matrix and were systematically characterised using XRD, FE-SEM, TEM, DLS, FTIR, TGA, SQUID etc. The drug loading, in vitro drug release, cellular uptake, cytotoxicity were evaluated and haemolytic effect was studied. RESULTS: The CF-NP showed good crystallinity with an average particle size of 21 nm and ferromagnetic nature. The DTX-loaded CF-NP (DCF-NP) showed 8.4% (w/w) drug loading with 81.8% loading efficiency with a sustained DTX release over time. An effective internalisation and anti-proliferative efficiency was observed in MCF-7 and MDA-MB-231 breast cancer cells and negligible haemolytic effect. CONCLUSION: The DCF-NP can have the potential for the effective delivery of DTX for breast cancer treatment.

Effect of Composition and Thickness on the Perpendicular Magnetic Anisotropy of (Co/Pd) Multilayers.

Magnetic materials with perpendicular magnetic anisotropy (PMA) have wide-ranging applications in magnetic recording and sensing devices. Multilayers comprised of ferromagnetic and non-magnetic metals (FM-NM) are interesting materials, as their magnetic anisotropy depends strongly on composition and growth parameters. In this context, (Co/Pd) multilayers have gained huge interest recently due to their robustness and tunable PMA. Here, we report a systematic study of the effect of composition on the magnetic anisotropy of (Co/Pd) multilayers grown by Direct Current (DC) magnetron sputtering. Four different series of (Co/Pd)×10 multilayers with different thicknesses of Co and Pd were examined. Vibrating sample magnetometery was used to determine the magnetic anisotropy of these films. X-ray diffraction and transmission electron microscopy experiments were performed to understand the structural morphology of the films. Our results showed that (Co/Pd)×10 multilayers exhibit PMA when the Co to Pd ratio is less than or equal to 1 and the thickness of Co layers is not more than 5 Å. Maximum effective anisotropy energy is shown by the films with a Co to Pd ratio of 1/3.

Pump-probe experiments at the TEMPO beamline using the low-α operation mode of Synchrotron SOLEIL.

The SOLEIL synchrotron radiation source is regularly operated in special filling modes dedicated to pump-probe experiments. Among others, the low-α mode operation is characterized by shorter pulse duration and represents the natural bridge between 50 ps synchrotron pulses and femtosecond experiments. Here, the capabilities in low-α mode of the experimental set-ups developed at the TEMPO beamline to perform pump-probe experiments with soft X-rays based on photoelectron or photon detection are presented. A 282 kHz repetition-rate femtosecond laser is synchronized with the synchrotron radiation time structure to induce fast electronic and/or magnetic excitations. Detection is performed using a two-dimensional space resolution plus time resolution detector based on microchannel plates equipped with a delay line. Results of time-resolved photoelectron spectroscopy, circular dichroism and magnetic scattering experiments are reported, and their respective advantages and limitations in the framework of high-time-resolution pump-probe experiments compared and discussed.

Indirect excitation of ultrafast demagnetization.

Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer. In comparison with an uncapped cobalt/palladium reference film, the initial demagnetization of the capped film occurs with a delayed onset and at a slower rate. Both observations are qualitatively in line with energy transport from the aluminum layer into the underlying magnetic film by the excited, hot electrons of the aluminum film. Our data thus confirm recent theoretical predictions.

Laser-induced ultrafast demagnetization in the presence of a nanoscale magnetic domain network.

Femtosecond magnetization phenomena have been challenging our understanding for over a decade. Most experiments have relied on infrared femtosecond lasers, limiting the spatial resolution to a few micrometres. With the advent of femtosecond X-ray sources, nanometric resolution can now be reached, which matches key length scales in femtomagnetism such as the travelling length of excited 'hot' electrons on a femtosecond timescale. Here we study laser-induced ultrafast demagnetization in [Co/Pd](30) multilayer films, which, for the first time, achieves a spatial resolution better than 100 nm by using femtosecond soft X-ray pulses. This allows us to follow the femtosecond demagnetization process in a magnetic system consisting of alternating nanometric domains of opposite magnetization. No modification of the magnetic structure is observed, but, in comparison with uniformly magnetized systems of similar composition, we find a significantly faster demagnetization time. We argue that this may be caused by direct transfer of spin angular momentum between neighbouring domains.

Assessment of real time traffic noise attenuation by tree belts within Kolkata city (India).

The study of the existing scenario of the effect of trees and shrubs as urban screen plantings for abating the level of real time traffic-induced noise pollution in Kolkata city deserves extreme importance. However, no such data are available till date in this area. This paper reports the result of a preliminary study to assess the attenuation of real time traffic noise by tree belts at three different important locations of the city. This measurement provides some new and interesting data which will be useful for further study and subsequent plan.