Ce-Ag Active Bimetallic Pairs in Two-Dimensional SnS2 for Enhancing NO2 Sensing.

Developing gas sensors capable of efficiently detecting harmful gases is urgent to protect the human environment. Here, an active Ce-Ag bimetallic pair was innovatively introduced into SnS2, which successfully exhibited excellent NO2 gas sensing performance. 0.8% Ce-SnS2-Ag showed a gas sensing response of 5.18 to 1 ppm of NO2 at a low temperature of 80 °C, with a lower limit of detection as low as 100 ppb. DFT calculations revealed that Ce atoms are substituted into the main lattice of SnS2, which opens up the interlayer spacing and serves as an anchor point to fix the Ag atoms in the interlayer. The Ce-Ag bimetallic pairs successfully modulate the electronic structure of SnS2, which promotes the adsorption and charge transfer between NO2 and Ce-SnS2-Ag and thus achieves such an outstanding gas sensing performance. This work opens an avenue for the rational functional modification of SnS2 with an optimized electronic structure and enhanced gas sensing.

Mechanistic insights into ball milling enhanced montmorillonite modification with tetramethylammonium for adsorption of gaseous toluene.

Montmorillonite is widely used for pollutants adsorption due to its porous structure and low price. However, the low specific surface area and small porosity limit its application in gas adsorption field. In this study, montmorillonite was organically modified using a facile dry ball milling method by tetramethylammonium bromide. The adsorption behaviour of toluene as a model VOC compound on organic montmorillonite was systematically investigated through adsorption breakthrough curves, adsorption kinetics and isotherms. After modification by ball milling, the specific surface area of ball milling with tetramethylammonium bromide for montmorillonite modification (BMTMt) was increased from 20.6 m2/g to 186.4 m2/g, and the microporosity proportion was up to 47%. Dynamic adsorption experiments showed that the best performance of BMTMt for toluene (55.9 mg/g) was 6 times higher than that of original montmorillonite (8.8 mg/g). Compared with the water bath preparation method, ball milling method promoted the intercalation of tetramethylammonium bromide into the layers of montmorillonite, resulting in a higher proportion of micropores. Density functional theory calculations indicated that the interaction between tetramethylammonium bromide and montmorillonite was mainly electrostatic forces, and the enhanced adsorption performance for toluene was mainly through microporous filling. BMTMt was proved to be a promising adsorbent for VOCs removal.

A novel view of the separate and simultaneous binding effects of docetaxel and anastrozole with calf thymus DNA: Experimental and in silico approaches.

DNA stands as the primary purpose of many anticancer drugs and according to the performed research on this field, some certain changes contain crucial functionalities in the regulated transcription of DNA. Therefore, the interaction between anticancer drugs and DNA play an important role in understanding their function and also provide a better groundwork for producing more efficient and newer drugs. Here, the interaction between Docetaxel (DO) and calf thymus DNA (ct DNA), in the presence and absence of Anastrozole (AN), has been examined through the usage of different methods that include isothermal titration calorimetry, multi-spectroscopic, viscometry, and molecular docking techniques. Interaction studies have been performed by preparing different molar ratios of DO with the constant ct DNA and AN concentration at pH = 6.8. The binding constants have been calculated to be 7.93 × 104 M-1 and 6.27 × 104 M-1, which indicate the strong binding of DO with ct DNA double helix in the absence and presence of AN, respectively. Thermodynamic parameters, which were obtained from fluorescence spectroscopy and isothermal titration calorimetry, have suggested that the binding of DO and AN to ct DNA as binary and ternary systems have been mainly driven by the electrostatic interactions. The relative viscosity of ct DNA has increased upon the addition of DO and AN, which confirms the interaction mode. A competitive binding study has reported that the enhanced emission intensity of ethidium bromide (EB) and acridine orange (AO), in the presence of ct DNA, have been quenched through the addition of DO and Anastrozole as binary and ternary systems. As it is indicated by these findings, DO is capable of displacing EB and AO from their binding site in ct DNA; hence, it can be concluded that DO and AN are able to intercalate into the base pairs of ct DNA in binary and ternary systems. Molecular docking studies have corroborated the mentioned experimental results.

Noncovalent tagging of siRNA with steroids for transmembrane delivery.

Short interfering RNA (siRNA) has broad applications in biology and medicine, and holds tremendous potential to become a new class of therapeutics for many diseases. As a highly anionic macrobiomolecule, its cytosolic delivery, however, has been a major roadblock in translation. Here, we report the development of small, bifunctional chemical tags capable of transporting siRNA directly into the cytosol. The bifunctional tags consist of a siRNA-binding moiety that interacts with siRNA non-covalently, and a steroid domain that readily fuses with the mammalian cell membrane. In contrast to the conventional covalently conjugated siRNA-steroid that enters cells largely via endocytosis which substantially limits siRNA bioavailability, the non-covalently tagged siRNA is cell membrane-permeant, avoiding the endocytic pathway. This new methodology enables effective RNA interference (RNAi) without the need of cationic transfection or endosomolytic agents, opening a new avenue for intracellular delivery of native biologics.

Transition Metal Intercalators as Anticancer Agents-Recent Advances.

The diverse anticancer utility of cisplatin has stimulated significant interest in the development of additional platinum-based therapies, resulting in several analogues receiving clinical approval worldwide. However, due to structural and mechanistic similarities, the effectiveness of platinum-based therapies is countered by severe side-effects, narrow spectrum of activity and the development of resistance. Nonetheless, metal complexes offer unique characteristics and exceptional versatility, with the ability to alter their pharmacology through facile modifications of geometry and coordination number. This has prompted the search for metal-based complexes with distinctly different structural motifs and non-covalent modes of binding with a primary aim of circumventing current clinical limitations. This review discusses recent advances in platinum and other transition metal-based complexes with mechanisms of action involving intercalation. This mode of DNA binding is distinct from cisplatin and its derivatives. The metals focused on in this review include Pt, Ru and Cu along with examples of Au, Ni, Zn and Fe complexes; these complexes are capable of DNA intercalation and are highly biologically active.

Multifunctional cationic polymer decorated and drug intercalated layered silicate (NLS) for early gastric cancer prevention.

A multifunctional compound that can prevent early gastric cancer is produced by intercalating 3.20% and 1.64% of 5-FU into the interlayer of montmorillonite (MMT) and attapulgite (At), respectively. A low molecular weight cationic polymer, polyethylenimine (PEI1200), is incorporated into the surface of the 5-FU-MMT and 5-FU-At to form the multifunctional layered silicate (NLS). The chemical structure and surface morphology of the NLS are characterized and the model drug of 5-FU is intercalated into the MMT and At. The cell viability determined by the MTT assay on the BGC-823 cell lines show that over 80% of the cells are live under the experimental conditions. The PEI-5-FU-MMT and PEI-5-FU-At can carry the report gene to the BGC-823 and COS-7 cell lines efficiently. Western blotting assay shows that the pTrail protein of the BGC-823 cell lines treated with PEI-5-FU-MMT/pTrail and PEI-5-FU-At/pTrail is up-regulated, whereas the cFLIP protein is down-regulated at 48 h compared to free 5-FU, PEI1200, MMT, and At, providing evidence that the NLS can increase the sensitivity of pTrail gene and improve the effects of pTrail gene therapy. Moreover, the Helicobacter pylori (HP) bacteria are adsorbed and immobilized efficiently on the surface of the NLS according to the LIVE/DEAD(®) BacLight™ Bacterial Viability Kit in the confocal fluorescence analysis. The histochemical analyses provide evidence that NLS/pTrail can prevent early gastric mucosa effectively.

C60 Intercalated Graphite as Nanolubricants.

We synthesized the novel nanocomposite consisting of alternately stacked single graphene sheets and a C60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C60 molecules into the graphite. It is found that the intercalated C60 molecules can rotate in between single graphene sheets by using 13C NMR measurements. The grease with the nanocomposite materials provides a much better lubricating performance than that with other additives that have been well-known up to now. This result exhibits that a C60 monolayer intercalated between graphenes plays an important role in lubricating behavior.