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A facile, green synthesis of selenium doped zinc oxide nano-antibiotic (Se-ZnO-NAB) using the Curcuma longa extract is reported to combat the increased emergence of methicillin-resistant Staphylococcus aureus (MRSA). The developed Se-ZnO-NAB were characterized for their physicochemical parameters and extensively evaluated for their toxicological potential in an animal model. The prepared Se-ZnO-NABs were characterized via Fourier transformed infrared spectroscopy to get functional insight into their surface chemistry, scanning electron microscopy revealing the polyhedral morphology with a size range of 36 ± 16 nm, having −28.9 ± 6.42 mV zeta potential, and inductively coupled plasma optical emission spectrometry confirming the amount of Se and Zn to be 14.43 and 71.70 mg L−1 respectively. Moreover, the antibacterial activity against MRSA showed significantly low minimum inhibitory concentration at 6.2 μg mL−1 when compared against antibiotics. Also, total protein content and reactive oxygen species production in MRSA, under the stressed environment of Se-ZnO-NAB, significantly (p < 0.05) decreased compared to the negative control. Moreover, the results of acute oral toxicity in rats showed moderate variations in blood biochemistry and histopathology of vital organs. The teratogenicity and fetal evaluations also revealed some signs of toxicity along with changes in biochemical parameters. The overall outcomes suggest that Se-ZnO-NAB can be of significant importance for combating multi-drug resistance but must be used with extreme caution, particularly in pregnancy, as moderate toxicity was observed at a toxic dose of 2000 mg kg−1. [ABSTRACT FROM AUTHOR]

The dramatic increase in antimicrobial resistance for pathogenic bacteria constitutes a key threat to human health. The Centers for Disease Control and Prevention has recently stated that the world is on the verge of entering the “post-antibiotic era”, one where more people will die from bacterial infections than from cancer. Recently, nanoparticles (NPs) have emerged as new tools that can be used to combat deadly bacterial infections. Nanoparticle-based strategies can overcome the barriers faced by traditional antimicrobials, including antibiotic resistance. In this tutorial review, we have highlighted multiple nanoparticle-based approaches to eliminate bacterial infections, providing crucial insight into the design of elements that play critical roles in creating antimicrobial nanotherapeutics. In particular, we have focused on the pivotal role played by NP-surface functionality in designing nanomaterials as self-therapeutic agents and delivery vehicles for antimicrobial cargo. [ABSTRACT FROM AUTHOR]

Gold nanoclusters are used as excellent scaffolds for the development of chemical and biological sensors due to their outstanding physical and chemical properties. In this study, a facile and green method has been employed for the preparation of highly fluorescent Au NCs by simply heating the gold precursor solution in the presence of a specially designed multidentate polymer ligand PTMP–PMAA. Herein, PTMP–PMAA functions as a reducing agent as well as a protecting agent. The Au NCs were characterized by fluorescence spectroscopy, ultraviolet absorption spectroscopy, dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), and powder X-ray diffraction (PXRD) and were found to exhibit yellow fluorescence (λem = 553 nm), a high quantum yield (22.6%), excellent stability and water-solubility. Based on aggregation-induced fluorescence quenching, the Au NCs@PTMP–PMAA fluorescent NCs were used for the detection of Fe3+ with an acceptable sensitivity having a detection limit of 3.0 μM and high selectivity. Moreover, Au NCs were also explored for the fluorescence imaging of Fe3+ in living H9c2 cardiac muscle cells presenting internalization with green fluorescence from the cells, suggesting their potential applicability as bioimaging agents. [ABSTRACT FROM AUTHOR]

A table of contents for the issue is presented.

Folate grafted and thiolated chitosan was synthesized and wrapped on the surface of mixed phosphatidylcholine based nanoliposomes (NLs) to improve the oral absorption and targeted pharmacological activity of anti-cancer drugs against breast cancer. In this study, a chitosan derived thiomer, having intrinsic properties of P-glycoprotein (P-gp) efflux pump inhibition, mucoadhesion and controlled drug release at a target site, was exploited to improve the performance of docetaxel (DTX) loaded NLs for better oral pharmacokinetics, targeted anti-cancer activity, liposomal stability and the physical characteristics of NLs. Thiomer enveloped nanoliposomes (ENLs) and bare nanoliposomes (NLs) were synthesized with the ingredient ratio pre-determined via Response Surface Methodology (RSM) plots by Design Expert® software. ENLs and NLs were thoroughly characterized for their surface chemistry, particle size, zeta potential, PDI, encapsulation efficiency, stability and release profile. ENLs were spherical in shape with a particle size of 328.5 ± 30 nm, a positive zeta potential of 18.81 ± 2.45 and a high encapsulation efficiency of 83% for DTX. Controlled release of DTX from formulations was observed for over 72 h for each formulation. The presence of thiol groups at the surface of the ENLs resulted in higher swelling and in situ gelling properties compared to the corresponding NLs. Furthermore, ENL/mucin mixtures showed a time dependent increase in viscosity for up to 12 h, leading to a 19.07-fold increased viscosity. Ex vivo permeation and P-glycoprotein inhibiting properties, studied in rat's small intestine, showed a 9.6-fold higher permeation and 13-fold enhancement of DTX in the presence of ENLs. In vitro cytotoxicity studies indicated that the ENLs can efficiently kill MD-MB-231 breast cancer cells with 200 fold lower IC50 values than DTX alone as a positive control. The pharmacokinetic study revealed that the ENLs significantly improved the oral bioavailability of DTX i.e. up to 13.6 fold as compared to an aqueous dispersion of DTX. Therefore, these enveloped hybrid nanoliposomes (ENLs) have the potential to be developed as useful nanocarriers for efficient oral delivery and breast cancer management using DTX. [ABSTRACT FROM AUTHOR]

A table of contents for the issue is presented.

We report the synthesis, characterization and evaluation of lecithin-drug hybrid nanocarriers (NCs) with enhanced oral bioavailability and anti-parasitic potential for poorly water-soluble drugs. Amphotericin B (AmB), a poor water-soluble drug with poor membrane penetrating ability, was selected as a model drug to demonstrate the potential of the lecithin-drug hybrid NCs. Lec-AmB NCs were prepared by the self-assembly of lecithin into nanoparticles (NPs) at a critical micellar concentration of 4 mg ml−1 and into liposomes at a critical liposomal concentration of 53 mg ml−1 in aqueous systems. The Lec-AmB NPs (200–300 nm) were further coated with polyethylene glycol (MW 600) and Tween 20, whereas the liposomes (70–90 nm) were used as such for this study. The Lec-AmB NCs were evaluated for their ability to boost in vivo oral pharmacokinetic parameters in rabbits and in vitro anti-leishmanial activity against the promastigotes of Leishmania tropica. A reciprocal relationship was observed between the size and drug encapsulation efficiency of the NPs, but no such relationship was observed in the case of the liposomes. More importantly, the oral bioavailability and anti-leishmanial activity of Lec-AmB NPs was enhanced up to 21- and 6.3-fold, and 21- and 2-fold, respectively, in the case of the liposomes. The improvement in the bioavailability and anti-leishmanial activity is very significant compared to the deoxycholate complex of AmB (water soluble, injectable market product: Anfotericina FADA®), and this study, thus shows the promising potential of easy-to-prepare NCs with improved therapeutic efficiency using phosphocholine-based biocompatible surfactants. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various articles within the issue on topics including bioanalytical and chemical sensors using neural cells, and electrochemical sensing of pathogens along with list of periodical editors which include Evan Williams, Renee Jiji and Qun Fang.

Salmonella enterica serotype Typhi (S. Typhi) is the causative agent of typhoid fever and remains a major health threat in most of the developing countries. The prompt diagnosis of typhoid directly from the patient's blood requires high level of sensitivity and specificity. Some of us were the first to report PCR based diagnosis of typhoid. This approach has since then been reported by many scientists using different genomic targets. Since the number of bacteria circulating in the blood of a patient can be as low as 0.3 cfu ml−1, there is always a room for improvement in diagnostic PCR. In the present study, the role of different types of nanoparticles was investigated to improve the existing PCR based methods for diagnosis and strain typing of S. Typhi (targeting Variable Number of Tandem Repeats [VNTR]) by using optimized PCR systems. Three different types of nanoparticles were used i.e., citrate stabilized gold nanoparticles, rhamnolipid stabilized gold and silver nanoparticles, and magnetic iron oxide nanoparticles. The non-specific amplification was significantly reduced in VNTR typing when gold and silver nanoparticles were used in an appropriate concentration. More importantly, the addition of nanoparticles decreased the non-specificity to a significant level in the case of multiplex PCR thus further validating the reliability of PCR for the diagnosis of typhoid. [ABSTRACT FROM AUTHOR]

An introduction is presented which discusses articles within the issue on topics including cobalt complexes as anticancer agents, along with information on members of the editorial and advisory board, and correction to an article on magnetic relaxation in furoate polymers.

Novel dual-porous carbon-supported palladium nanoparticle (Pd NP) catalysts were prepared by sequential carbonization and reduction of microporous organic polymer-encaged PdCl2. The diverse pore structure of microporous organic polymers provides a reservoir for the palladium precursors and prevents Pd NPs from sintering during the carbonization and reaction. The microporous structure has a significant effect on the size and dispersion of palladium NPs. The average size of the Pd NPs (in the range of 4–6 nm) was tuned by changing the pore size distribution and the carbonization temperature. The resulting carbon-supported Pd NPs were characterized by TEM, BET, XRD, and XPS and the Pd loading was calculated by AAS. The encaged Pd NP catalysts prepared by this methodology exhibited outstanding stability and reusability in the Heck reaction and could be reused at least 10 times without appreciable loss of activity. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the author discusses several article within the issue on topics including organic photovoltaic materials, Pristine graphene dispersion and fiber-shaped supercapacitor along with front cover and editors of the periodical including B. Lotsch, X. Feng and M. Wei.

We report a simple and economical colorimetric bacterial sensing strategy with catalytic amplification using dopamine-capped iron oxide (Dop-Fe3O4) nanoparticles. These nanoparticles catalyse the oxidation of a chromogenic substrate in the presence of H2O2 into a green colored product. The catalytic activity of the nanoparticles is inhibited in the presence of bacteria, providing naked eye detection of bacteria at 104 cfu mL−1 and by spectrophotometric detection down to 102 cfu mL−1. [ABSTRACT FROM AUTHOR]

Functional microporous organic polymers (MOPs) are attractive in a wide range of applications including gas separation, catalysis, and energy storage. There is a lack of cost-effective processes to produce functional MOPs at industrial scale, which in fact limits their practical applications. Here, we propose a new low-cost strategy, based on the Scholl reaction, which can directly link rigid building blocks to obtain MOPs with high surface area and highly microporous structures. More importantly, this method is suitable for various building blocks and can be used as a general bottom-up approach to produce a variety of multifunctional MOPs. Multifaceted applications of these materials are also demonstrated by their large gas storage capacity, high catalytic activity, luminescence and semiconducting properties. [ABSTRACT FROM AUTHOR]

This work is aimed at producing uniform microporous polymer nanoparticles (MPNs) and studying their hydrogen storage properties. Synthesis of vinylbenzyl chloride (VBC)/divinylbenzene (DVB) copolymers by emulsion polymerization yield fairly uniform gel-type precursor nanoparticles and the particle size can be tuned from 36 to 131 nm by adjusting the emulsifier dose. These are analogous to gel-type suspension polymerized particles typically of 10–500 μm in diameter and are essentially non-porous in the dry state having only a very nominal surface area (1–2 m2/g, BET surface area). Friedel–Crafts-type hyper-cross-linking reaction of these precursors yields uniform MPNs with extremely high surface area up to ca.1500 m2/g (BET surface area). Moreover, MPNs present more micropore volume (0.56 cm3/g), higher hydrogen adsorption capacity (1.59 wt%, 77.3 K, 1.13 bar), higher isosteric heats for hydrogen and faster adsorption rate as compared to polydisperse micro-size analogues previously reported. [ABSTRACT FROM AUTHOR]