Engineering two-dimensional metal oxides and chalcogenides for enhanced electro- and photocatalysis

Two-dimensional (2D) metal oxides and chalcogenides (MOs & MCs) have been regarded as a new class of promising electro- and photocatalysts for many important chemical reactions such as hydrogen evolution reaction, CO2 reduction reaction and N2 reduction reaction in virtue of their outstanding physicochemical properties. However, pristine 2D MOs & MCs generally show the relatively poor catalytic performances due to the low electrical conductivity, few active sites and fast charge recombination. Therefore, considerable efforts have been devoted to engineering 2D MOs & MCs by rational structural design and chemical modification to further improve the catalytic activities. Herein, we comprehensively review the recent advances for engineering technologies of 2D MOs & MCs, which are mainly focused on the intercalation, doping, defects creation, facet design and compositing with functional materials. Meanwhile, the relationship between morphological, physicochemical, electronic, and optical properties of 2D MOs & MCs and their electro- and photocatalytic performances is also systematically discussed. Finally, we further give the prospect and challenge of the field and possible future research directions, aiming to inspire more research for achieving high-performance 2D MOs & MCs catalysts in energy storage and conversion fields

Structural Diversity and Biological Activities of Diterpenoids Derived from Euphorbia fischeriana Steud

Diterpenoids are the focus of natural product drug discovery because of their great structural diversity and pronounced biological activities. Euphorbia fischeriana Steud is a Chinese traditional medicinal herb for curing edema, ascites, and cancer. This plant contains rich diterpenoids. Based on the carbon skeleton and substituents, it can be classified into thirteen subtypes: ent-abietane, daphnane, tigliane, ingenane, ent-atisane, ent-rosane, ent-kaurene, ent-kaurane, secotigliane, lathyrane, ent-pimarene, isopimarene and dimeric. In this paper, we reviewed the chemical structures and biological activities of 90 diterpenoids isolated from this medicinal herb. We hope that this work can serve as a reference for further research of these diterpenoids and lay the foundation for drug discovery

Engineering two-dimensional metal oxides via surface functionalization for biological applications

Two-dimensional (2D) metal oxides (MOs) have attracted a considerable amount of attention for various biological applications due to their unique physicochemcial properties such as high photothermal response, temperature superconductivity, photoluminescence, flexibility, unique catalytic capability, plasmonic tunability and relatively low toxicity. However, the sophisticated physiological environments in biosystems stimulate various explorations of surface functionalization to improve the dispersity, stability and biocompatibility of 2D MOs. Moreover, 2D MOs exhibit remarkably tuneable properties via creating oxygen vacancies or doping, which endow 2D MOs with additional capabilities in biological applications. The large surface to volume ratio inherent in these materials also allows easy functionalization and maximal interaction with the external environment. Much work has been done in tailoring 2D MOs through physical/chemical functionalization for use in a diverse range of biomedical applications such as biosensors, bioimaging, drug/gene delivery carriers or even as therapeutic agents. In this review, current progress on 2D MOs functionalized for various biological applications will be presented. Additional relevant issues concerning the research challenges, technology limitations, and future trends have also been discussed

Anti-Cancer Activities of Diterpenoids Derived from Euphorbia fischeriana Steud

Euphorbia fischeriana Steud is an essential oriental folk medicine used for healing cancer, edema and tuberculosis. Recently, its anticancer activitity has attracted more attention. A volume of research has indicated that diterpenoids are the major anticancer active constituents from this medicinal herb. In this review, we aimed to provide a summary of the promising anticancer diterpenoids from this plant; many diterpenoids mentioned in this article are newly discovered diterpenoids. According to the carbon skeleton and substituents, they can be classified into eight subtypes: ent-abietane, daphnane, tigliane, ingenane, ent-atisane, ent-rosane, ent-kaurane, and lathyrane. Futhermore, their key anticancer mechanisms and protein targets of these compounds will be discussed. These natural diterpenoids could provide a reservoir for drug discovery

A Comparative Study of the Use of Mesoporous Carbon and Mesoporous Silica as Drug Carriers for Oral Delivery of the Water-Insoluble Drug Carvedilol

Mesoporous carriers have been extensively applied to improve the dissolution velocity and bioavailability of insoluble drugs. The goal of this work was to compare the drug-loading efficiency (LE) and drug-dissolution properties of mesoporous silica nanoparticles (MSN) and mesoporous carbon nanoparticles (MCN) as drug vectors oral delivery of water-insoluble drugs. For this purpose, MSN and MCN with similar particle size, surface area, and mesoporous diameter were prepared to precisely evaluate the effects of different textures on the drug-loading and dissolution behavior of insoluble drugs. Carvedilol (CAR), a Bio-pharmaceutic Classification System (BCS) class II drug, was loaded in the MSN and MCN by the solvent adsorption method and solvent evaporation method with different carrier−drug ratios. The carboxylated MCN (MCN−COOH) had a higher LE for CAR than MSN for both the two loading methods due to the strong adsorption effect and π−π stacking force with CAR. In vitro drug dissolution study showed that both MSN and MCN-COOH could improve the dissolution rate of CAR compared with the micronized CAR. In comparison to MSN, MCN-COOH displayed a slightly slower dissolution profile, which may be ascribed to the strong interaction between MCN-COOH and CAR. Observation of cell cytotoxicity and gastrointestinal mucosa irritation demonstrated the good biocompatibility of both MSN and MCN−COOH. The present study encourages further research of different carriers to determine their potential application in oral administration