Metalloimmunotherapy with Rhodium and Ruthenium Complexes: Targeting Tumor-Associated Macrophages

Tumor associated macrophages (TAMs) suppress the cancer immune response and are a key target for immunotherapy. The effects of ruthenium and rhodium complexes on TAMs have not been well characterized. To address this gap in the field, a panel of 22 dirhodium and ruthenium complexes were screened against three subtypes of macrophages, triple-negative breast cancer and normal breast tissue cells. Experiments were carried out in 2D and biomimetic 3D co-culture experiments with and without irradiation with blue light. Leads were identified with cell-type-specific toxicity toward macrophage subtypes, cancer cells, or both. Experiments with 3D spheroids revealed complexes that sensitized the tumor models to the chemotherapeutic doxorubicin. Cell surface exposure of calreticulin, a known facilitator of immunogenic cell death (ICD), was increased upon treatment, along with a concomitant reduction in the M2-subtype classifier arginase. Our findings lay a strong foundation for the future development of ruthenium- and rhodium-based chemotherapies targeting TAMs.     

Adaptive control of anti-aircraft missile launcher mounted on a mobile base

This paper presents the problem of control of anti-aircraft missile launcher mounted on a moving carrier-vehicle. Direct excitations on the vehicle from the road cause adverse vibrations of the launcher. In order to increase the precision of the guiding system in the conditions of self-propelled movement of the setup on a bumpy road, the adaptive control algorithm was proposed. Some research results of computer simulation are presented in a graphical form.     

Investigation of factors affecting ruthenium complexation in ROMP reactions of oxygen-containing norbornene derivatives using Grubbs first generation initiator

We report the synthesis and ring-opening metathesis polymerisation (ROMP) of a range of oxygen-containing norbornene derivatives using Grubbs first generation initiator. The ROMP reactions were followed by proton NMR and the identification of propagating species present was facilitated by the addition of excess tricyclohexyl phosphine and copper chloride (a phosphine scavenger), with the intention of further probing the structural, steric, and geometric factors determining the tendency for oxygen atoms in the monomers to complex to the ruthenium centre.     

Determination of Catechin and Epicatechin in an Extract from Uncaria tomentosa Bark by TLC with Chemically Modified Stationary Phases

JPC – Journal of Planar Chromatography – Modern TLC - The conditions used for TLC and HPTLC analysis of catechins have been optimized. Chemically modified stationary phases (HPTLC CN,...     

Orthogonal Detection of Nitroaromatic Explosives via Direct Voltammetry Coupled to Enzyme‐Mediated Biocatalysis

This article describes a rapid and reliable electrochemical/enzymatic method of verifying the presence of nitroaromatic explosives. The new technique leverages both conventional voltammetric analysis and biocatalytic conversion of TNT. The simultaneous use of independent measurement schemes, based on two distinct processes, dramatically increases the information content and offers substantially improved reliability while minimizing the occurrence of false alarms. This has been accomplished by coupling direct voltammetric analysis with the biocatalytic conversion of the TNT substrate via nitroreductase (NR), which reduces a nitro group of TNT using NADH as an electron donor. This chemical reduction (30 s timescale) can then be observed using square‐wave voltammetry by examination of the reductive and oxidative features. This novel protocol was found to be selective for TNT, not only when compared to DNT and NT, but also to other explosive species such as RDX and PETN. This unique dual‐mode detection strategy for measuring TNT at a single device holds considerable promise for improving the probability of explosive detection and hence for diverse security screening applications.     

Adsorption behaviour of sugars versus their activity in single and multicomponent liquid solutions

In this work the activity of three carbohydrates (sucrose, glucose and fructose) in highly concentrated aqueous solutions was studied along with its effect on the adsorption behaviour of the investigated compounds. Activities of individual sugars in aqueous solutions of single solute as well as in binary mixtures were quantified on the basis of solubility properties. Solid–liquid equilibria of sugars were correlated with the NRTL (nonrandom, two liquid) model of activity coefficient formulation. Activities of individual sugars were incorporated into the single component adsorption isotherm model, which reproduced accurately the course of the adsorption equilibria of sugars in aqueous solutions obtained experimentally in previous work using an ion-exchange resin. Activities of sugars determined in binary solute systems along with the single component isotherms were used to predict competitive adsorption equilibria. To calculate adsorbed phase concentrations of individual sugars in binary mixtures the adsorbed solution theory was adopted. The isotherm shapes calculated were compared to the data of competitive adsorption from the former study and found to be able to describe these experimental results.     

Photochromism and hydrolysis of aromatic Schiff base N,N′-bis(salicylidene)-p-phenylenediamine (BSP) studied in heterogeneous environments

A photochromic symmetric Schiff base, N,N′-bis(salicylidene)-p-phenylenediamine has been studied by means of stationary spectroscopic absorption and emission techniques in the IR and UV-vis spectral range in heterogeneous environments: microporous and mesoporous molecular sieves and micellar systems. The intermolecular hydrogen bonds between the molecule studied and silanol groups in mesoporous material have led initially to the stabilization of the cis-keto tautomer and later to a very effective hydrolysis. Persisting two-step color changes have been found to occur after the UV irradiation of the molecule studied encapsulated in microporous and mesoporous molecular sieves.     

Donor-acceptor-donor tetrazines containing a ferrocene unit: synthesis, electrochemical and spectroscopic properties

Donor-acceptor-donor tetrazines containing ferrocene moieties and phenyl unit as a pi-bridge have been synthesized and characterized. UV-vis spectroscopic and cyclic voltamperometric results indicate sizable intramolecular charge transfer interactions in the ground state when the ferrocene is directly bound to the tetrazine. On the other hand, the results show reduction of the electron-donor strength of ferrocene moieties when there is a phenyl linkage. Both tetrazines display a high reduction potential. The role of ferrocenyl groups appear to be detrimental to maximize the cubic hyperpolarizability gamma of tetrazines, as compared to purely organic groups such as thiophene. A possible explanation for this behavior may originate from metal-to-ligand charge transfer processes.