Fabrication of poly(ϵ-caprolactone)/paclitaxel (core)/chitosan/zein/multi-walled carbon nanotubes/doxorubicin (shell) nanofibers against MCF-7 breast cancer

In the present study, paclitaxel (PTX), multi-walled carbon nanotubes (MWCNTs), and doxorubicin (DOX) have been simultaneously doped into the poly(ϵ-caprolactone) (PCL)/chitosan/zein core-shell nanofibers to increase its cytotoxicity for MCF-7 breast cancers killing. The physico-chemical properties of synthesized nanofibers were determined by scanning electron microscope, Fourier-transform infrared spectroscopy, tensile strength, and degradation rate determinations. The in vitro release studies demonstrated the sustained release of drugs from core-shell nanofibrous scaffold. The cytotoxicity and compatibility of core-shell nanofibers were investigated by their treating with MCF-7 breast cancer cells and L929 normal cells, respectively. PCL/PTX/chitosan/zein/MWCNTs/DOX core-shell nanofibers containing 1 wt% MWCNTs, 100 μg ml⁻¹ DOX and 100 μg ml⁻¹ PTX had a high biocompatibility with a 84% MCF-7 cancer cells killing. The in vivo studies revealed the synergic effects of MWCNTs and anticancer drugs on the tumor inhibition. This method could be considered as a new way for developing of MWCNTs loaded-nanofibers for cancer treatment in future.     

Synthesis of bismuth mixed oxide by thermal decomposition of a coprecipitate precursor

Bismuth mixed oxide powders were prepared by oxalate coprecipitation process. The thermal decomposition behaviour of the coprecipitate precursors has been followed by thermal analysis (TG-DTA) and FTIR spectroscopy. During the decomposition of the precursor, several intermediates species were detected and a mechanism of formation of mixed oxide by this method is proposed. After the thermal treatment, the precursor obtained of suggested formula Ca₃[Bi₆O₆(C₂O₄)₄(OH)₃NO₃]0.5H₂O, has led to the formation of CaBi₂O₄ at shorter reaction time than the traditional ceramic method. In order to consolidate the results, the coprecipitation in absence of oxalic precipitant under the same conditions was examined. XRD and scanning electron spectroscopy were used to study particles sizes and morphology.     

Pseudocapacitive Lithium Storage of Cauliflower-Like CoFe2O4 for Low-Temperature Battery Operation

Binary transition-metal oxides (BTMOs) with hierarchical micro–nano-structures have attracted great interest as potential anode materials for lithium-ion batteries (LIBs). Herein, we report the fabrication of hierarchical cauliflower-like CoFe₂O₄ (cl-CoFe₂O₄) via a facile room-temperature co-precipitation method followed by post-synthetic annealing. The obtained cauliflower structure is constructed by the assembly of microrods, which themselves are composed of small nanoparticles. Such hierarchical micro–nano-structure can promote fast ion transport and stable electrode–electrolyte interfaces. As a result, the cl-CoFe₂O₄ can deliver a high specific capacity (1019.9 mAh g⁻¹ at 0.1 A g⁻¹), excellent rate capability (626.0 mAh g⁻¹ at 5 A g⁻¹), and good cyclability (675.4 mAh g⁻¹ at 4 A g⁻¹ for over 400 cycles) as an anode material for LIBs. Even at low temperatures of 0 °C and −25 °C, the cl-CoFe₂O₄ anode can deliver high capacities of 907.5 and 664.5 mAh g⁻¹ at 100 mA g⁻¹, respectively, indicating its wide operating temperature. More importantly, the full-cell assembled with a commercial LiFePO₄ cathode exhibits a high rate performance (214.2 mAh g⁻¹ at 5000 mA g⁻¹) and an impressive cycling performance (612.7 mAh g⁻¹ over 140 cycles at 300 mA g⁻¹) in the voltage range of 0.5–3.6 V. Kinetic analysis reveals that the electrochemical performance of cl-CoFe₂O₄ is dominated by pseudocapacitive behavior, leading to fast Li⁺ insertion/extraction and good cycling life.     

Mapping protein pockets through their potential small-molecule binding volumes: QSCD applied to biological protein structures

Previously we demonstrated a method, Quantized Surface Complementarity Diversity (QSCD), of defining molecular diversity by measuring shape and functional complementarity of molecules to a basis set of theoretical target surfaces [Wintner E.A. and Moallemi C.C., J. Med. Chem., 43 (2000) 1993]. In this paper we demonstrate a method of mapping actual protein pockets to the same basis set of theoretical target surfaces, thereby allowing categorization of protein pockets by their properties of shape and functionality. The key step in the mapping is a `dissection' algorithm that breaks any protein pocket into a set of potential small molecule binding volumes. It is these binding volumes that are mapped to the basis set of theoretical target surfaces, thus measuring a protein pocket not as a single surface but as a collection of molecular recognition environments.     

Effect of probiotication on antioxidant and antibacterial activities of pomegranate juices from sour and sweet cultivars

There is an increasing interest in using pomegranate juice as a natural antioxidant rather than synthetic compounds. In this study, the antioxidant capacities of probioticated and nonprobioticated aril juices of sweet (SWV) and sour (SV) pomegranate cultivars were determined by two different methods: ferric reducing antioxidant power (FRAP) and 1,1-diphenyl 2-picrylhydrazyl assay. Total counts of Lactobacillus casei GG increased by about 3 log in SWV and 2 log in SV juices after incubation for 48 h. Probiotication improved the antioxidant activity of SWV juice from 74.4% to 91.82%, and SV juice from 82.64% to 97.8%. Based on the FRAP value, the reducing power of the probioticated pomegranate juices was also much stronger than the nonprobioticated juices. The FRAP values for SWV and SV probioticated juices were 97.34 and 120.7 mmol L(-1), respectively, which were notably higher than 85.87 and 93.4 mmol L(-1) for SWV and SV nonprobioticated juices. Both fermentated and nonfermentated juices exhibited a potent and wide-spectrum antibacterial effect, with the highest activity against Pseudomonas aeruginosa. SV juice showed wider zones of growth inhibition. The results of this study verify for the first time that probiotication of SWV and SV pomegranate juices can add to their beneficial antioxidant activities.     

Selective and Sensitive Fluorometric Determination of Piroxicam Based on Nitrogen-doped Graphene Quantum Dots and Gold Nanoparticles Coated with Phenylalanine

Journal of Fluorescence - In this study, a sensitive fluorimetric method is proposed for the determination of piroxicam using nitrogen graphene quantum dots (N-GQDs) and gold nanoparticles coated...     

Synthesis and characterization of the new pyrochlore Bi1.5Sb1.5−xNbxMnO7 solid solution

The solid solution with formula Bi_1.5Sb_1.5−xNb_xMnO₇ has been synthesized using the ceramic method at 1000 °C. This solid solution was crystallized in the pyrohlore structure in cubic lattice with Fd-3 m space group. The cell parameter increases linearly with increase in the niobium concentration. The magnetic susceptibility measurements achieved between 4 and 300 K show a paramagnetic behaviour with an effective moment 5.84 μ_β for Bi_1.5Sb_1.5MnO₇ compound (x = 0) and 5.61 μ_B for Bi_1.5Nb_1.5MnO₇ compound (x = 1.5) indicating “ + 2” oxidation state for manganese ion. The electric conductivity measured using the complex impedance spectroscopy method put in evidence an increase of the electric conductivity with the temperature, and the antimony compound is slightly more conductor than the niobium compound; results indicate electronic conductivity with semi-conducting behaviour.     

A simple and expedient method for the stepwise synthesis of 2-ethoxy-(4H)-3,1-benzoxazine-4-ones

A simple and practical route is described for the synthesis of 2-efhoxy-(4H)-3,1 -benzoxazine-4-ones using the coupling reaction of anthranilic acid derivatives with diethyl dicarbonate following with fast cyclization of the carbamate adduct with a dehydrocyclization agent such as cyanuric chloride and N,N′-dicyclohexylcarbodiimide in PEG at room temperature.High yields of the products obtained under mild reaction conditions with simple work-up of the reaction mixture.     

Partially resorbable composite bone plate with controlled degradation rate, desired mechanical properties and bioactivity

Rate of polymer degradation is very important for implantable biomaterials since controlling the degradation rate may complement the biological response and affected mechanical property requirements. In spite of numerous publications on the potential use of combinations of poly lactic acid/bioactive glass fillers for degradable bone plate, little information exists on the controlling degradation rate and its effects on the other aspects such as biomechanical compatibility, bioactivity, etc. Our previous study revealed that a composite bone plate consist of poly l-lactic acid/braided bioactive glass fibers has the initial mechanical properties near to cortical bone. In this study, degradation rate and mechanical behavior of the composite bone plate were assessed, and also degradation rate was controlled by using proper manufacturing process and improving bonding between matrix and reinforcement. Moreover, bioactivity of the composite was considered before and after controlling degradation rate, because of the important role of bioactivity and ion release in healing acceleration. Results showed that degradation process of the composite could be controlled properly. Strength of the treated composite decreased only about 5% through 2 weeks and about 35% after 8 weeks while, the strength loss for the untreated composites was about 50 and 70 percent after 2 weeks and 8 weeks of degradation respectively. Although calcium-phosphate formation on the surface of the composite was postponed in the treated samples, the bioactivity of the composite remained unchanged and bone-like apatite was formed on the composite surface which is important for the application of the composite in bone tissue environment.