The futuristic applications of transition metal dichalcogenides for cancer therapy.

The second-most common cause of death resulting from genetic mutations in DNA sequences is cancer. The difficulty in the field of anticancer research is the application of the traditional methods, which also affects normal cells. Mutations, genetic replication alterations, and chromosomal abnormalities have a direct impact on the effectiveness of anticancer drugs at different stages. Presently, therapeutic techniques utilize nanotechnology, transition metal dichalcogenides (TMDCs), and robotics. TMDCs are being increasingly employed in tumor therapy and biosensing applications due to their biocompatibility, adjustable bandgap, versatile functionality, exceptional photoelectric properties, and wide range of applications. This study reports the advancement of nanoplatforms based on TMDCs that are specifically engineered for responsive and intelligent cancer therapy. This article offers a thorough examination of the current challenges, future possibilities for theranostic applications using TMDCs, and recent progress in employing TMDCs for cancer therapy. Currently, there is significant interest in two-dimensional (2D) TMDCs nanomaterials as ultrathin unique physicochemical properties. These materials have attracted attention in various fields, including biomedicine. Due to their inherent ability to absorb near-infrared light and their exceptionally large surface area, significant efforts are being made to prepare multifunctional nanoplatforms based on 2D TMDCs.

Transition-Metal-Based Nanozymes: Synthesis, Mechanisms of Therapeutic Action, and Applications in Cancer Treatment.

Cancer, as one of the leading causes of death worldwide, drives the advancement of cutting-edge technologies for cancer treatment. Transition-metal-based nanozymes emerge as promising therapeutic nanodrugs that provide a reference for cancer therapy. In this review, we present recent breakthrough nanozymes for cancer treatment. First, we comprehensively outline the preparation strategies involved in creating transition-metal-based nanozymes, including hydrothermal method, solvothermal method, chemical reduction method, biomimetic mineralization method, and sol-gel method. Subsequently, we elucidate the catalytic mechanisms (catalase (CAT)-like activities), peroxidase (POD)-like activities), oxidase (OXD)-like activities) and superoxide dismutase (SOD)-like activities) of transition-metal-based nanozymes along with their activity regulation strategies such as morphology control, size manipulation, modulation, composition adjustment and surface modification under environmental stimulation. Furthermore, we elaborate on the diverse applications of transition-metal-based nanozymes in anticancer therapies encompassing radiotherapy (RT), chemodynamic therapy (CDT), photodynamic therapy (PDT), photothermal therapy (PTT), sonodynamic therapy (SDT), immunotherapy, and synergistic therapy. Finally, the challenges faced by transition-metal-based nanozymes are discussed alongside future research directions. The purpose of this review is to offer scientific guidance that will enhance the clinical applications of nanozymes based on transition metals.

Gas Evolution as a Tool to Study Reaction Kinetics Under Biomimetic Conditions.

The field of bioorthogonal chemistry is rapidly growing, presenting successful applications of organic and transition metal-catalysed reactions in cells and living systems (in vivo). The development of such reactions typically proceeds through many iterative steps focused on biocompatibility and fast reaction kinetics to ensure product formation. However, obtaining kinetic data, even under simulated biological (biomimetic) conditions, remains a challenge due to substantial concentrations of salts and biomolecules hampering the use of typically employed solution-phase analytical techniques. In this study, we explored the suitability of gas evolution as a probe to study kinetics under biomimetic conditions. As proof of concept, we show that the progress of two transition metal-catalysed bioorthogonal chemical reactions can be accurately monitored, regardless of the complexity of the medium. As such, we introduce a protocol to gain more insight into the performance of a catalytic system under biomimetic conditions to further progress iterative catalyst development for in vivo applications.

Anticancer Metallocenes and Metal Complexes of Transition Elements from Groups 4 to 7.

With the progression in the field of bioinorganic chemistry, the role of transition metal complexes as the most widely used therapeutics is becoming a more and more attractive research area. The complexes of transition metals possess a great variety of attractive pharmacological properties, including anticancer, anti-inflammatory, antioxidant, anti-infective, etc., activities. Transition metal complexes have proven to be potential alternatives to biologically active organic compounds, especially as antitumor agents. The performance of metal coordination compounds in living systems is anticipated to differ generally from the action of non-metal-containing drugs and may offer unique diagnostic and/or therapeutic opportunities. In this review, the rapid development and application of metallocenes and metal complexes of elements from Groups 4 to 7 in cancer diagnostics and therapy have been summarized. Most of the heavy metals discussed in the current review are newly discovered metals. That is why the use of their metal-based compounds has attracted a lot of attention concerning their organometallic and coordination chemistry. All of this imposes more systematic studies on their biological activity, biocompatibility, and toxicity and presupposes further investigations.

Dipeptide coacervates as artificial membraneless organelles for bioorthogonal catalysis.

Artificial organelles can manipulate cellular functions and introduce non-biological processes into cells. Coacervate droplets have emerged as a close analog of membraneless cellular organelles. Their biomimetic properties, such as molecular crowding and selective partitioning, make them promising components for designing cell-like materials. However, their use as artificial organelles has been limited by their complex molecular structure, limited control over internal microenvironment properties, and inherent colloidal instability. Here we report the design of dipeptide coacervates that exhibit enhanced stability, biocompatibility, and a hydrophobic microenvironment. The hydrophobic character facilitates the encapsulation of hydrophobic species, including transition metal-based catalysts, enhancing their efficiency in aqueous environments. Dipeptide coacervates carrying a metal-based catalyst are incorporated as active artificial organelles in cells and trigger an internal non-biological chemical reaction. The development of coacervates with a hydrophobic microenvironment opens an alternative avenue in the field of biomimetic materials with applications in catalysis and synthetic biology.

Modular Fabrication of Bioorthogonal Nanozymes for Biomedical Applications.

The incorporation of transition metal catalysts (TMCs) into nanoscaffolds generates nanocatalysts that replicate key aspects of enzymatic behavior. The TMCs can access bioorthogonal chemistry unavailable to living systems. These bioorthogonal nanozymes can be employed as in situ "factories" for generating bioactive molecules where needed. The generation of effective bioorthogonal nanozymes requires co-engineering of the TMC and the nanometric scaffold. This review presents an overview of recent advances in the field of bioorthogonal nanozymes, focusing on modular design aspects of both nanomaterial and catalyst and how they synergistically work together for in situ uncaging of imaging and therapeutic agents.

Nanomaterials-Based Field-Effect Transistor for Protein Sensing: New Advances.

It is crucial for early stage medical diagnostics to identify disease biomarkers at ultralow concentrations. A wide range of analytes can be identified using low-dimensional materials to build highly sensitive, targeted, label-free, field-effect transistor (FET) biosensors. Two-dimensional (2D) materials are preferable for high-performance biosensing because of their dramatic change in resistivity upon analyte adsorption or biomarker detection, tunable electronic properties, high surface activities, adequate stability, and layer-dependent semiconducting properties. We give a succinct overview of interesting applications for protein sensing with various architectural styles, such as 2D transition metal dichalcogenides (TMDs)-based FETs that include carbon nanotubes (CNTs), graphene (Gr), reduced graphene oxide (rGr), 2D transition-metal carbides (MXene), and Gr/MXene heterostructures. Because it might enable individuals to perform better, this review will be an important contribution to the field of medical science. These achievements demonstrate point-of-care diagnostics' abilities to detect biomarkers at ultrahigh performance levels. A summary of the present opportunities and challenges appears in the conclusion.

Late-Stage C-H Activation of Drug (Derivative) Molecules with Pd(ll) Catalysis.

This review comprehensively analyses representative examples of Pd(II)-catalyzed late-stage C-H activation reactions and demonstrates their efficacy in converting C-H bonds at multiple positions within drug (derivative) molecules into diverse functional groups. These transformative reactions hold immense potential in medicinal chemistry, enabling the efficient and selective functionalization of specific sites within drug molecules, thereby enhancing their pharmacological activity and expanding the scope of potential drug candidates. Although notable articles have focused on late-stage C-H functionalization reactions of drug-like molecules using transition-metal catalysts, reviews specifically focusing on late-stage C-H functionalization reactions of drug (derivative) molecules using Pd(II) catalysts are required owing to their prominence as the most widely utilized metal catalysts for C-H activation and their ability to introduce a myriad of functional groups at specific C-H bonds. The utilization of Pd-catalyzed C-H activation methodologies demonstrates impressive success in introducing various functional groups, such as cyano (CN), fluorine (F), chlorine (Cl), aromatic rings, olefin, alkyl, alkyne, and hydroxyl groups, to drug (derivative) molecules with high regioselectivity and functional-group tolerance. These breakthroughs in late-stage C-H activation reactions serve as invaluable tools for drug discovery and development, thereby offering strategic options to optimize drug candidates and drive the exploration of innovative therapeutic solutions.

Ni/Mn-Complex-Tethered Tetranuclear Polyoxovanadates: Crystal Structure and Inhibitory Activity on Human Hepatocellular Carcinoma (HepG-2).

Polyoxometalates (POMs) exhibit unique structural characteristics and excellent physical and chemical properties, which have attracted significant attention from scholars in the fields of anticancer research and chemotherapy. Herein, we successfully synthesized and structurally characterized two novel polyoxovanadates (POVs), denoted as POVs-1 and POVs-2, where [M(1-vIM)4]2[VV4O12]·H2O (M: NiII and MnII, 1-vinylimidazole abbreviated as 1-vIM) serve as ligands. The two POVs are isomeric and consist of fundamental structural units, each comprising one [V4O12]4- cluster, two [M(1-vIM)4]2+ cations, and one water molecule. Subsequently, we evaluated the cell viability of human hepatocellular carcinoma (HepG-2) cells treated with the synthesized POVs using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide) assay. And the changes in cell nucleus morphology, mitochondrial membrane potential (Δψm), and reactive oxygen species levels in HepG-2 exposed to POVs were monitored using specific fluorescent staining techniques. Both hybrid POVs showed potent inhibitory activities, induing apoptosis in HepG-2 cells along with significant mitochondria dysfunction and a burst of reactive oxygen species. Notably, the inhibitory effects of POVs-2 were more pronounced than those of POVs-1, which is primarily attributed to the different transition metal ions present. These findings underscore the intricate relationship between the metal components, structural characteristics, and the observed antitumor activities in HepG-2 cells.

Versatile MXene composite probe-mediated homogeneous electrochemiluminescence biosensor with integrated signal transduction and near-infrared modulation strategy for concanavalin A detection.

Based on the highly specific interaction between concanavalin A (Con A) and glucose (Glu), a competitive electrochemiluminescence (ECL) biosensor was constructed for ultrasensitive detection of Con A. Nanocomposites with excellent electrocatalytic and photothermal properties were obtained by covalently bonding zinc oxide quantum dots (ZnO QDs) to vanadium carbide MXene (V2C MXene) surfaces. The modification of ZnO QDs hinders the aggregation of V2C MXene and increases the catalytic activity of oxygen reduction reaction, thus amplifying the luminol cathodic emission. In addition, the excellent photothermal performance of the V2C MXene-ZnO QDs can convert light energy into heat energy under the irradiation of 808 nm near infrared laser, thus increasing the temperature of the reaction system and accelerating the electron transfer process to realize the synergistic amplified homogeneous ECL system. This innovative work not only enriches the fundamental research on multifunctional MXene nanomaterials for biosensing, but also provides an effective strategy for ECL signal amplification.

The Effectiveness of Cyrene as a Solvent in Exfoliating 2D TMDs Nanosheets.

The pursuit of environmentally friendly solvents has become an essential research topic in sustainable chemistry and nanomaterial science. With the need to substitute toxic solvents in nanofabrication processes becoming more pressing, the search for alternative solvents has taken on a crucial role in this field. Additionally, the use of toxic, non-economical organic solvents, such as N-methyl-2 pyrrolidone and dimethylformamide, is not suitable for all biomedical applications, even though these solvents are often considered as the best exfoliating agents for nanomaterial fabrication. In this context, the success of producing two-dimensional transition metal dichalcogenides (2D TMDs), such as MoS2 and WS2, with excellent captivating properties is due to the ease of synthesis based on environment-friendly, benign methods with fewer toxic chemicals involved. Herein, we report for the first time on the use of cyrene as an exfoliating agent to fabricate monolayer and few-layered 2D TMDs with a versatile, less time-consuming liquid-phase exfoliation technique. This bio-derived, aprotic, green and eco-friendly solvent produced a stable, surfactant-free, concentrated 2D TMD dispersion with very interesting features, as characterized by UV-visible and Raman spectroscopies. The surface charge and morphology of the fabricated nanoflakes were analyzed using ς-potential and scanning electron microscopy. The study demonstrates that cyrene is a promising green solvent for the exfoliation of 2D TMD nanosheets with potential advantages over traditional organic solvents. The ability to produce smaller-sized-especially in the case of WS2 as compared to MoS2-and mono/few-layered nanostructures with higher negative surface charge values makes cyrene a promising candidate for various biomedical and electronic applications. Overall, the study contributes to the development of sustainable and environmentally friendly methods for the production of 2D nanomaterials for various applications.

Recent Progress in NiH-Catalyzed Linear or Branch Hydrofunctionalization of Terminal or Internal Alkenes.

The construction of C-C and C-X (X = N, O, Si, etc.) bonds is an important field in organic synthesis and methodology. In recent decades, studies on transition metal-catalyzed functionalization of alkenes have been on the rise. The individual properties of different transition metals determine the type of reaction that can be applied. Generally, post-transition metals with a large number of electrons in the d-orbit such as Mn, Fe, Co, Ni, Cu and Zn, etc., can be applied to more reaction types than pre-transition metals with a small number of electrons (e.g., Ti, Zr, etc.). Alkyl nickel intermediates formed by oxidative addition could couple with various of nucleophiles or electrophiles. Moreover, nickel has several oxidation valence states, which can flexibly realize a variety of catalytic cycles. These characteristics make nickel favored by researchers in the field of functionalization of alkenes, especially for the hydrofunctionalization of alkenes. Both terminal and internal alkenes could be converted, and the strategies of synthesizing linear and branched compounds have been expanded. Moreover, the guiding groups in alkenes played an almost decisive role in the regional selectivity, and the ligand or temperature also had regulating effects. Herein, we will give a comprehensive and timely overview of the works about the Ni-catalyzed hydrofunctionalization of alkenes and some insights on regional selectivity.

Transition metal-catalysis in interrupted borrowing hydrogen strategy.

In recent times, the transition metal-catalyzed borrowing hydrogen (BH) and interrupted borrowing hydrogen (IBH) strategies have attracted much attention and represent atom- and step-economic processes to access diverse building blocks via various C-C and C-heteroatom bond-forming reactions. The advantages of these approaches include (i) use of feedstock chemicals, (ii) high atom economy, (iii) no pre-activation of the substrates, and (iv) producing water as the only by-product. In this context, several synthetic strategies have been developed in this regime for the past few decades. To the best of our knowledge, no review article describes the important concepts of interrupted borrowing hydrogen (IBH) reaction. This review article highlights the recent advances in the IBH strategy and its application in sustainable chemical synthesis, particularly C-C bond formation using methanol as a C1 source, synthesis of 3,3'-bisindolylmethanes (3,3'-BIMs), α-branched ketones/diketones, and regioselective alkylation of N-heterocycles.

Transition Metal Catalysis in Living Cells: Progress, Challenges, and Novel Supramolecular Solutions.

The importance of transition metal catalysis is exemplified by its wide range of applications, for example in the synthesis of chemicals, natural products, and pharmaceuticals. However, one relatively new application is for carrying out new-to-nature reactions inside living cells. The complex environment of a living cell is not welcoming to transition metal catalysts, as a diverse range of biological components have the potential to inhibit or deactivate the catalyst. Here we review the current progress in the field of transition metal catalysis, and evaluation of catalysis efficiency in living cells and under biological (relevant) conditions. Catalyst poisoning is a ubiquitous problem in this field, and we propose that future research into the development of physical and kinetic protection strategies may provide a route to improve the reactivity of catalysts in cells.

Hybrid Inorganic Complexes as Cancer Therapeutic Agents: In-vitro Validation.

A series of novel mixed transition metal-Magnesium tartarate complexes of general formulation [MMg(C4H4O6)2 .xH2O] (where M = Mn, Fe, Co, Ni, Cu and Zn) is prepared with bidentate tartarate ligand. The synthesized complexes (C1 to C6) are characterized by various analytical techniques such as Elemental analysis, Thermo gravimetric analysis, FT-IR Spectroscopy, X-ray Diffraction, Magnetic susceptibility study etc. All complexes exhibit the composition MMgL2 where M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) and L = bidentate tartarate ligand. Analytical data reveals all complexes possesses 1:1 (metal: ligand) ratio. FT-IR spectral study shows that bidentate tartarate ligand coordinate with metal ion in a bidentate manner through two oxygen atoms. Thermo gravimetric analysis of all complexes shows that degradation curves of complexes agrees with recommended formulae of the complexes. X-ray diffraction technique suggests that all complexes (C1 to C6) are polycrystalline in nature. All newly synthesized metal tartarate complexes and ligand were screened in vitro for their anticancer activity against human breast cancer (MDA-MB-231) cell line. The bioassays of all these complexes showed C3 (Co) and C5 (Cu) Mg-tartarate complexes contains maximum antiproliferative activity at 200 µg/ml concentration on MDA-MB-231 cells as compared to other complexes. MDA-MB-231 cells treated with C3 (Co) and C5 (Cu) Mg-tartarate complexes also showed inhibition in cell migration.

Four-Membered Bimetallic Carbon Complex [(M(η5 -C5 (CH3 )5 ))2 (µ-NPh)(µ-C)] (M=Fe, Ru, Os) - An Ambiphilic Carbene with Lone Pair and σ-Hole Reactivity.

Singlet carbenes are extensively studied compounds capable of electrophilic, nucleophilic or ambiphilic behaviour. The ambiphilic reactivity of singlet carbenes has been conventionally observed in orthogonal planes. Here, we report a detailed bonding and reactivity study of a homobimetallic carbon complex [(MCp*)2 (µ-NPh)(µ-C)] (1M, M=Fe, Ru, Os) that shows ambiphilicity in the same direction. The structure of this complex can be considered as two fused three-membered M-C-M and M-N-M rings. The bonding analysis suggests that these 17 valence electron homobimetallic complexes have one formal M-M bond with a bridging carbene centre featuring a high-lying spn -hybridised lone pair. Accordingly, the carbene centre shows high proton affinity and act as a good 2e- donor to Lewis acids and transition metal fragment. Apart from the transition metal non-bonding electrons, the π-framework of M-C-M and M-N-M arms can be best described as 3c-2e- bonds. The two transition metals in the four-membered skeleton generate many low-lying, virtual orbitals. These low-lying virtual orbitals induce electron excitation from the spn -hybrid orbital in presence of H- and other 2e- donor ligands such as PMe3 , NHC and CO. Hence, the spn -hybrid lone pair orbital shows σ-hole reactivity in presence of Lewis bases.

Biodegradable Antibacterial Bioorthogonal Polymeric Nanocatalysts Prepared by Flash Nanoprecipitation.

Bioorthogonal activation of pro-dyes and prodrugs using transition-metal catalysts (TMCs) provides a promising strategy for imaging and therapeutic applications. TMCs can be loaded into polymeric nanoparticles through hydrophobic encapsulation to generate polymeric nanocatalysts with enhanced solubility and stability. However, biomedical use of these nanostructures faces challenges due to unwanted tissue accumulation of nonbiodegradable nanomaterials and cytotoxicity of heavy-metal catalysts. We report here the creation of fully biodegradable nanocatalysts based on an engineered FDA-approved polymer and the naturally existing catalyst hemin. Stable nanocatalysts were generated through kinetic stabilization using flash nanoprecipitation. The therapeutic potential of these nanocatalysts was demonstrated through effective treatment of bacterial biofilms through the bioorthogonal activation of a pro-antibiotic.

Two-Dimensional Transition Metal Dichalcogenide Based Biosensors: From Fundamentals to Healthcare Applications.

There has been an exponential surge in reports on two-dimensional (2D) materials ever since the discovery of graphene in 2004. Transition metal dichalcogenides (TMDs) are a class of 2D materials where weak van der Waals force binds individual covalently bonded X-M-X layers (where M is the transition metal and X is the chalcogen), making layer-controlled synthesis possible. These individual building blocks (single-layer TMDs) transition from indirect to direct band gaps and have fascinating optical and electronic properties. Layer-dependent opto-electrical properties, along with the existence of finite band gaps, make single-layer TMDs superior to the well-known graphene that paves the way for their applications in many areas. Ultra-fast response, high on/off ratio, planar structure, low operational voltage, wafer scale synthesis capabilities, high surface-to-volume ratio, and compatibility with standard fabrication processes makes TMDs ideal candidates to replace conventional semiconductors, such as silicon, etc., in the new-age electrical, electronic, and opto-electronic devices. Besides, TMDs can be potentially utilized in single molecular sensing for early detection of different biomarkers, gas sensors, photodetector, and catalytic applications. The impact of COVID-19 has given rise to an upsurge in demand for biosensors with real-time detection capabilities. TMDs as active or supporting biosensing elements exhibit potential for real-time detection of single biomarkers and, hence, show promise in the development of point-of-care healthcare devices. In this review, we provide a historical survey of 2D TMD-based biosensors for the detection of bio analytes ranging from bacteria, viruses, and whole cells to molecular biomarkers via optical, electronic, and electrochemical sensing mechanisms. Current approaches and the latest developments in the study of healthcare devices using 2D TMDs are discussed. Additionally, this review presents an overview of the challenges in the area and discusses the future perspective of 2D TMDs in the field of biosensing for healthcare devices.

Highly Elastic, Healable, and Durable Anhydrous High-Temperature Proton Exchange Membranes Cross-Linked with Highly Dense Hydrogen Bonds.

Proton exchange membranes (PEMs) with excellent durability and working stability are important for PEM fuel cells with extended service life and enhanced reliability. In this study, highly elastic, healable, and durable electrolyte membranes are fabricated by the complexation of poly(urea-urethane), ionic liquids (ILs), and MXene nanosheets (denoted as PU-IL-MX). The resulting PU-IL-MX electrolyte membranes have a tensile strength of ≈3.86 MPa and a strain at break of ≈281.89%. The PU-IL-MX electrolyte membranes can act as high temperature PEMs to conduct protons under an anhydrous condition of the temperatures above 100 °C. Importantly, the ultrahigh density of hydrogen-bond-cross-linked network renders PU-IL-MX membranes excellent IL retention properties. The membranes can maintain more than ≈98% of their original weight and show no decline of proton conductivity after being placed under highly humid conditions of ≈80 °C and relative humidity of ≈85% for 10 days. Moreover, due to the reversibility of hydrogen bonds, the membranes can heal damage under the working conditions of fuel cells to restore their original mechanical properties, proton conductivities, and cell performances.

Metal-Free One-Pot Multi-Functionalization of Unsaturated Compounds with Interelement Compounds by Radical Process.

In recent years, the importance of "environmentally friendly manufacturing" has been increasing toward the establishment of a resource-recycling society. In organic synthesis, as well, it is becoming increasingly important to develop new synthetic strategies with resource conservation and the recycling of elemental resources in mind, rather than just only synthesis. Many studies on the construction of frameworks of functional molecules using ionic reactions and transition-metal-catalyzed reactions have been reported, but most of them have focused on the formation of carbon-carbon bonds. However, it is essential to introduce appropriate functional groups at appropriate positions in molecules in order for the molecules to express their functions, and furthermore, the highly selective preparation of multiple functional groups is considered important for the creation of new functional molecules. In this review, we focus on radical reactions with high functional group selectivity and overview the recent progress in practical methods for the simultaneous introduction of multiple functional groups and propose future synthetic strategies that emphasize the recycling of elemental resources and environmental friendliness.