Effect of thermal annealing on a bilayer polyvinyl alcohol/polyacrylic acid electrospun hydrogel nanofibres loaded with doxorubicin and clarithromycin for a synergism effect against osteosarcoma cells

Polyvinyl alcohol/polyacrylic acid (PVA/PAA) bilayer hydrogel nanofibres were successfully fabricated by electrospinning and physically crosslinked via heat treatment. The effects of the thermal annealing process on the structure, morphology, swelling, thermal properties and hydrophilicity of electrospun nanofibres were investigated. In addition, these membranes were also used to incorporate doxorubicin and clarithromycin for osteosarcoma treatment, one in each layer. These drugs were used because it is hypothesized in this work that a synergism occurs between both drugs. So, these membranes were analyzed towards their dual-drug release and potential cytotoxicity towards the U2OS human osteosarcoma cell line. Moreover, the water contact angle, disintegration, swelling and weight loss studies confirmed the rapid swelling and improved water stability of the annealed PVA/PAA bilayer nanofibres. The annealed bilayer nanofibres exhibited an increase in the average diameter and degree of crystallinity. In addition, the results revealed that a variation occurred in the degree of hydrophilicity of annealed PVA/PAA bilayer nanofibres. The PAA nanofibres surface exhibited higher hydrophilicity than the PVA nanofibres surface. Drug delivery presented to be as fast rate release for clarithromycin and slow-rate release for doxorubicin, which may be advantageous because both drugs exhibited to be synergetic for certain dosages presenting the combination of the drugs higher than 50% of cell inhibition, while these membranes had higher inhibition values (up to 90%), which was attributed to the PAA but also the drugs. These unique properties are of potential interest in drug delivery applications for dual drug delivery where the tunability of surfaces is desirable.     

A Novel Docetaxel-Biotin Chemical Conjugate for Prostate Cancer Treatment

A novel conjugate of docetaxel and biotin (designated as IDD-1010) was designed and chemically synthesized via an ester linkage at position 2’ carbon in docetaxel. The synthesized pure IDD-1010 exhibits a potent anti-cancer activity in in vitro and in vivo studies. At 10 nM, IDD-1010 has induced increased apoptosis and mitotic arrest of PC3-Luc prostate cancer cells, causing aneuploidy and cell death at higher concentrations. Toxicology studies indicate that the maximal tolerated dose (MTD) of IDD-1010 is 150 mg/kg in mice; equivalent to about 12.2 mg/kg of body weight, or to about an 850 mg dose for a patient weighing 70 kg. The MTD-treated mice exhibited weight gain similar to that of the control group, with no gross pathological signs at 14 days post-dosing. At a lower dose, IDD-1010 treatment did not lead to any significant weight loss in mice, although decreased the tumor volume stemming from injecting cancer cells into the dorsal loop of mouse prostate, and it was found to be more potent than Paclitaxel (reference drug). Similarly, IDD-1010 treatment significantly reduced tumor weight and thereby increased the percentage of mice survival as compared to reference drug-treated and control groups. To summarize, the described experiments using IDD-1010, as compared to the reference drug, strongly suggest a potential treatment utility with a wider therapeutic window for prostate cancer. Henceforth, clinical research on such a novel drug candidate would be greatly worthwhile.     

Random matrix analysis of human EEG data

We use random matrix theory to demonstrate the existence of generic and subject-independent features of the ensemble of correlation matrices extracted from human EEG data. In particular, the spectral density as well as the level spacings was analyzed and shown to be generic and subject independent. We also investigate number variance distributions. In this case we show that when the measured subject is visually stimulated the number variance displays deviations from the random matrix prediction.     

Two-component interference effect: model of a spin-polarized transport

The effect of spin-involved interaction on the transport properties of disordered two-dimensional electron systems with ferromagnetic contacts is described using a two-component model. Components representing spin-up and spin-down states are supposed to be coupled at a discrete set of points. We have found that due to the additional interference arising in two-component systems the difference between conductances for the parallel and antiparallel orientations of the contact magnetization changes its sign as a function of the length of the conducting channel.     

Transmission properties of random point scatterers for waves with two-band dispersion law

The scattering problem is considered for the one-dimensional Dirac equation whose potential is a system of randomly distributed point scatterers. Types of such scatterers are described. The probability densities for the transmission and transformation disbalance coefficients are determined in the high-energy region and various averaged characteristic are calculated.     

Combined use of Overhauser spectroscopy and NMR diffusion experiments for mapping the hydration structure of nucleosides: structure and dynamics of uridine in water

Complementary results from 13C intermolecular nuclear Overhauser effects (NOE), 1H-13C heteronuclear Overhauser spectroscopy (HOSEY) and 1H-NMR diffusion measurements were used for probing the structure of the first solvation shell of uridine in water. It is demonstrated that a cyclic dihydrate is formed. The two water molecules produce two hydrogen bonds with the two oxygen atoms from the pyrimidine ring and accept only one hydrogen bond from the amide proton. The dihydrate has only a short lifetime as compared with the rotational correlation time of the free nucleoside. The chemical exchange constant of the amide proton with water is then estimated by diffusion experiments. The results are consistent with previous data obtained for uracil in water and provide interesting information about water accessibility in nucleic acid bases.     

Frobenius-perron resonances for maps with a mixed phase space

Resonances of the time evolution (Frobenius-Perron) operator P for phase space densities have recently been shown to play a key role for the interrelations of classical, semiclassical, and quantum dynamics. Efficient methods to determine resonances are thus in demand, in particular, for Hamiltonian systems displaying a mix of chaotic and regular behavior. We present a powerful method based on truncating P to a finite matrix which not only allows us to identify resonances but also the associated phase space structures. It is demonstrated to work well for a prototypical dynamical system.     

Analysis of Rhamnolipid Biosurfactants Produced Through Submerged Fermentation Using Orange Fruit Peelings as Sole Carbon Source

The fermentative production of rhamnolipid biosurfactant from Pseudomonas aeruginosa MTCC 2297 was carried out by submerged fermentation using various cost-effective waste materials such as orange peelings, carrot peel waste, lime peelings, coconut oil cake, and banana waste. The orange peel was found to be the best substrate generating 9.18 g/l of rhamnolipid biosurfactant with a surface tension reduction up to 31.3 mN/m. The production was growth independent, and optimum conditions were standardized. The emulsifying activity was highest against kerosene (73.3%). Rhamnolipid components were purified and separated by ethyl acetate extraction, preparative silica gel column chromatography, high-performance liquid chromatography and thin-layer chromatography. The major rhamnolipid components were characterized, by fast atom bombardment mass spectrometry, as a mixture of dirhamnolipids and monorhamnolipids.