Chemiresistive gas sensor based on Mo0.5W0.5S2 alloy nanoparticles with good selectivity and ppb-level limit of detection to ammonia.

Transition metal dichalcogenides (TMDs) are promising materials for chemiresistive gas sensor, while TMD alloys (two chalcogenide or/and metal elements) with tunable electronic structures have drawn little attention in gas sensing. Herein, Mo0.5W0.5S2 alloy nanoparticles (NPs) were prepared by a facile sonication exfoliation method and then tested for ammonia sensing. The crystal structure, geometric morphology, and elemental composition of Mo0.5W0.5S2 NPs were investigated. The gas sensing measurements demonstrated Mo0.5W0.5S2 NPs with good response to ammonia at 80 °C with a limit of detection down to 500 part per billion (ppb). The sensor also displayed good stability as well as superb selectivity to ammonia in the presence of interferences, such as methanol, acetone, benzene, and cyclohexane. The theoretical calculations revealed Mo and W atoms at edges (such as Mo0.5W0.5S2 (010)) of sheet-like NPs as the active sites for ammonia adsorption. Electrons donated by the adsorbed ammonia were combined with holes in p-type Mo0.5W0.5S2 NPs, and the concentration of the main charge carrier was reduced, resulting in resistance enhancement.

Glioma diagnosis and therapy: Current challenges and nanomaterial-based solutions.

Glioma is often referred to as one of the most dreadful central nervous system (CNS)-specific tumors with rapidly-proliferating cancerous glial cells, accounting for nearly half of the brain tumors at an annual incidence rate of 30-80 per a million population. Although glioma treatment remains a significant challenge for researchers and clinicians, the rapid development of nanomedicine provides tremendous opportunities for long-term glioma therapy. However, several obstacles impede the development of novel therapeutics, such as the very tight blood-brain barrier (BBB), undesirable hypoxia, and complex tumor microenvironment (TME). Several efforts have been dedicated to exploring various nanoformulations for improving BBB permeation and precise tumor ablation to address these challenges. Initially, this article briefly introduces glioma classification and various pathogenic factors. Further, currently available therapeutic approaches are illustrated in detail, including traditional chemotherapy, radiotherapy, and surgical practices. Then, different innovative treatment strategies, such as tumor-treating fields, gene therapy, immunotherapy, and phototherapy, are emphasized. In conclusion, we summarize the article with interesting perspectives, providing suggestions for future glioma diagnosis and therapy improvement.

Expression of MiRNA-29b and MiRNA-31 and their diagnostic and prognostic values in Egyptian females with breast cancer.

Breast cancer is a major health threat to women globally. Many circulating microRNAs are non-invasive cancer biomarkers. In this study, the expression of miR-29b and miR-31 was assessed in blood samples from 200 patients with breast cancer and wholesome volunteer women using quantitative reverse transcriptase PCR to evaluate their role in the disease. MiR-29b was significantly overexpressed in patients compared to controls. Multivariate regression analysis showed that it was an established risk factor for relapse and mortality. MiR-31 was significantly under-expressed in patients. It was an established risk factor for relapse and was strongly associated with mortality. For the prediction of relapse, miR-29b had a sensitivity of 81.25% and a specificity of 88.24% at a cutoff of > 30.09, while miR-31 had a sensitivity of 87.50% and a specificity of 79.41% at a cutoff of 0.12. The specificity was enhanced to 100% by combining the values of miR-29b and miR-31. In predicting mortality, miR-29b exhibited a sensitivity of 90% and a specificity of 97.5% at a cutoff of > 48.10. At a cutoff of 0.119, miR-31 exhibited a sensitivity of 87.50% and a specificity of 79.41%. High miR-29b expression and low miR-31 expression were linked with a low survival rate. MiR-29b and miR-31 could be useful markers for predicting breast cancer relapse and mortality.

Synthesis, Nanoformulations, and In Vitro Anticancer Activity of N-Substituted Side Chain Neocryptolepine Scaffolds.

The naturally occurring neocryptolepine (5-Methylindolo [2,3-b]quinoline) and its analogs exhibited prominent anticancer and antimalarial activity. However, the main problem of this class of compounds is their poor aqueous solubility, hampering their bioavailability and preventing their clinical development. To overcome the problem of insolubility and to improve the physicochemical and the pharmacological properties of 5-Methylindolo [2,3-b]quinoline compounds, this work was designed to encapsulate such efficient medical compounds into mesoporous silica oxide nanoemulsion (SiO2NPs). Thus, in this study, SiO2NPs was loaded with three different concentrations (0.2 g, 0.3, and 0.6 g) of 7b (denoted as NPA). The findings illustrated that the nanoparticles were formed with a spherical shape and exhibited small size (less than 500 nm) using a high concentration of the synthesized chemical compound (NPA, 0.6 g) and good stabilization against agglomeration (more than -30 mv). In addition, NPA-loaded SiO2NPs had no phase separation as observed by our naked eyes even after 30 days. The findings also revealed that the fabricated SiO2NPs could sustain the release of NPA at two different pH levels, 4.5 and 7.4. Additionally, the cell viability of the produced nanoemulsion system loaded with different concentrations of NPA was greater than SiO2NPs without loading, affirming that NPA had a positive impact on increasing the safety and cell viability of the whole nanoemulsion. Based on these obtained promising data, it can be considered that the prepared NPA-loaded SiO2NPs seem to have the potential for use as an effective anticancer drug nanosystem.

Strategic Design of Intelligent-Responsive Nanogel Carriers for Cancer Therapy.

Owing to the distinctive constituents of tumor tissue from those healthy organs, nanomedicine strategies show significant potentials in smart drug delivery. Nowadays, stimuli-responsive nanogels are playing increasingly important roles in the application of cancer therapy because of their sensitivity to various internal or external physicochemical stimuli, which exhibit site-specific and markedly enhanced drug release. Besides, nanogels are promising as drug carriers because of their porous structures, good biocompatibility, large surface area, and excellent capability with drugs. Taking advantage of multiresponsiveness, recent years have witnessed the rapid evolution of stimulus-responsive nanogels from monoresponsive to multiresponsive systems; however, there lacks a comprehensive review summarizing these reports. In this Review, we discuss the properties, synthesis, and characterization of nanogels. Moreover, tumor microenvironment and corresponding designing strategies for stimuli-response nanogels, both exogenous (temperature, magnetic field, light) and endogenous (pH, biomolecular, redox, ROS, pressure, hypoxia) are summarized on the basis of the recent advances in multistimuli-responsive nanogel systems. Nanogel and two-dimensional material composites show excellent performance in the field of constructing multistimulus-responsive nanoparticles and precise intelligent drug release integrated system for multimodal cancer diagnosis and therapy. Finally, potential progresses and suggestions are provided for the further design of hybrid nanogels based on emerging two-dimensional materials.

2D materials for bone therapy.

Due to their prominent physicochemical properties, 2D materials are broadly applied in biomedicine. Currently, 2D materials have achieved great success in treating many diseases such as cancer and tissue engineering as well as bone therapy. Based on their different characteristics, 2D materials could function in various ways in different bone diseases. Herein, the application of 2D materials in bone tissue engineering, joint lubrication, infection of orthopedic implants, bone tumors, and osteoarthritis are firstly reviewed comprehensively together. Meanwhile, different mechanisms by which 2D materials function in each disease reviewed below are also reviewed in detail, which in turn reveals the versatile functions and application of 2D materials. At last, the outlook on how to further broaden applications of 2D materials in bone therapies based on their excellent properties is also discussed.

Highly sensitive ethylene glycol-doped PEDOT-PSS organic thin films for LPG sensing.

In this study, for the first time we report the fabrication of low-cost ethylene glycol (EG)-doped PEDOT-PSS (poly 3,4-ethylenedioxythiophene:polystyrene sulfonate) organic thin film sensors for the detection of LPG at room temperature. The prepared thin films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) spectroscopy and thermogravimetric analysis (TGA) techniques for the analysis of their structural and morphological features. The doping of EG strongly improved the conductivity of pure PEDOT-PSS films by three orders of magnitude. The gas sensing responses of pristine and doped PEDOT-PSS thin films were investigated at room temperature by fabricating a sensor device on an ITO-coated glass substrate. The gas sensing characteristics of the prepared thin films were investigated for liquified petroleum gas (LPG), dimethyl propane, methane and butane test gases. The EG-doped PEDOT-PSS thin films exhibited excellent sensitivity for all the test gases, especially towards LPG, at room temperature. The sensitivity of the doped PEDOT-PSS films was recorded to be >90% for LPG with improved response and recovery time. The stability study indicated that the sensing response of doped PEDOT-PSS thin films was highly stable over a period of 30 days. Due to enhanced sensitivity, stability and fast response and recovery times, these EG-doped PEDOT-PSS thin films can be used in gas sensor technology, especially towards the detection of LPG at room temperature.