Analytical Methods for Assessing Thiol Antioxidants in Biological Fluids: A Review.

Redox metabolism is an integral part of the glutathione system, encompassing reduced and oxidized glutathione, hydrogen peroxide, and associated enzymes. This core process orchestrates a network of thiol antioxidants like thioredoxins and peroxiredoxins, alongside critical thiol-containing proteins such as mercaptoalbumin. Modifications to thiol-containing proteins, including oxidation and glutathionylation, regulate cellular signaling influencing gene activities in inflammation and carcinogenesis.

Gadolinium Doping Modulates the Enzyme-like Activity and Radical-Scavenging Properties of CeO Nanoparticles.

Their unique physicochemical properties and multi-enzymatic activity make CeO nanoparticles (CeO NPs) the most promising active component of the next generation of theranostic drugs. When doped with gadolinium ions, CeO NPs constitute a new type of contrast agent for magnetic resonance imaging, possessing improved biocatalytic properties and a high level of biocompatibility. The present study is focused on an in-depth analysis of the enzyme-like properties of gadolinium-doped CeO NPs (CeO:Gd NPs) and their antioxidant activity against superoxide anion radicals, hydrogen peroxide, and alkylperoxyl radicals.

Albumin Retains Its Transport Function after Interaction with Cerium Dioxide Nanoparticles.

The interaction of inorganic nanomaterials with biological fluids containing proteins can lead not only to the formation of a protein corona and thereby to a change in the biological activity of nanoparticles but also to a significant effect on the structural and functional properties of the biomolecules themselves. This work studied the interaction of nanoscale CeO, the most versatile nanozyme, with human serum albumin (HSA). Fourier transform infrared spectroscopy, MALDI-TOF mass spectrometry, UV-vis spectroscopy, and fluorescence spectroscopy confirmed the formation of HSA-CeO nanoparticle conjugates.

Hybrid Polyelectrolyte Capsules Loaded with Gadolinium-Doped Cerium Oxide Nanoparticles as a Biocompatible MRI Agent for Theranostic Applications.

Layer-by-layer (LbL) self-assembled polyelectrolyte capsules have demonstrated their unique advantages and capability in drug delivery applications. These ordered micro/nanostructures are also promising candidates as imaging contrast agents for diagnostic and theranostic applications. Magnetic resonance imaging (MRI), one of the most powerful clinical imaging modalities, is moving forward to the molecular imaging field and requires advanced imaging probes.

Oxidative metabolism of neutrophils in acute coronary syndrome.

Background: Inflammation in acute coronary syndrome (ACS) involves neutrophil activation and oxidative stress. Here, we studied the production of reactive oxygen species (ROS) by neutrophils in ACS.

Methods: The study included 42 patients, men and women aged 46-91 years with ischaemic heart disease (IHD), non-ST-segment elevation ACS and ST-segment elevation ACS.

Effect of Low-Dose Line-Spectrum and Full-Spectrum UV on Major Humoral Components of Human Blood.

Ultraviolet blood irradiation (UVBI) is an alternative approach to the treatment of infectious diseases of various pathogeneses. Recently, UVBI has attracted particular interest as a new immunomodulatory method. Experimental studies available in the literature demonstrate the absence of precise mechanisms of the effect of ultraviolet radiation (UV) on blood.

Peroxidase-like Activity of CeO Nanozymes: Particle Size and Chemical Environment Matter.

The enzyme-like activity of metal oxide nanoparticles is governed by a number of factors, including their size, shape, surface chemistry and substrate affinity. For CeO nanoparticles, one of the most prominent inorganic nanozymes that have diverse enzymatic activities, the size effect remains poorly understood. The low-temperature hydrothermal treatment of ceric ammonium nitrate aqueous solutions made it possible to obtain CeO aqueous sols with different particle sizes (2.

Green and Sustainable Ultrasound-Assisted Anodic Electrochemical Preparation of Graphene Oxide Dispersions and Their Antioxidant Properties.

A fast method for preparing aqueous graphene oxide (GO) dispersions by electrochemical oxidation of a graphite anode without preliminary intercalation with oxidizing agents is proposed. Ultrasonic probing was used in the modulation mode of ultrasonic waves (work/rest) for more efficient graphite oxidation-exfoliation. It is shown that the 4/2 s mode of ultrasonic modulation is the most effective due to the probe material's low corrosion while maintaining the optimum synthesis temperature not exceeding 30-35 °C and achieving the best characteristics of the resulting product.

High-Throughput Preparation of Uncontaminated Graphene-Oxide Aqueous Dispersions with Antioxidant Properties by Semi-Automated Diffusion Dialysis.

A semi-automated diffusion-dialysis purification procedure is proposed for the preparation of uncontaminated graphene oxide (GO) aqueous dispersions. The purification process is integrated with analytical-signal processing to control the purification degree online by several channels: oxidation-reduction potential, conductivity, and absorbance. This approach reduces the amounts of reagents for chemical treatment during dialysis.

Switchable Nanozyme Activity of Porphyrins Intercalated in Layered Gadolinium Hydroxide.

In this study, organo-inorganic nanohybrids with enzyme-like activity were prepared by in situ intercalation of anionic 5,10,15,20-tetrakis-(4-sulfonatophenyl)porphyrin and its complexes with Zn(II) and Pd(II) (, M = 2H, Zn(II) and Pd(II)) into gadolinium layered hydroxide (). The combination of powder XRD, CHNS analysis, FT-IR, EDX, and TG confirmed the layered structure of the reaction products. The basal interplanar distances in samples were 22.

Facile Synthesis of Stable Cerium Dioxide Sols in Nonpolar Solvents.

A method is proposed for the preparation of stable sols of nanocrystalline cerium dioxide in nonpolar solvents, based on surface modification of CeO nanoparticles obtained by thermal hydrolysis of concentrated aqueous solutions of ammonium cerium(IV) nitrate with residues of 2-ethylhexanoic and octanoic acids. The synthesis was carried out at temperatures below 100 °C and did not require the use of expensive and toxic reagents. An assessment of the radical-scavenging properties of the obtained sols using the superoxide anion-radical neutralization model revealed that they demonstrate notable antioxidant activity.

New facets of nanozyme activity of ceria: lipo- and phospholipoperoxidase-like behaviour of CeO nanoparticles.

Cerium dioxide nanoparticles have a special place among engineered nanomaterials due to the wide range of their enzyme-like activities. They possess SOD-, catalase- and peroxidase-like properties, as well as recently discovered phosphatase-, photolyase-, phospholipase- and nuclease-like properties. Advancing biomedical applications of CeO-based nanozymes requires an understanding of the features and mechanisms of the redox activity of CeO nanoparticles when entering the vascular bed, especially when interacting with lipid-protein supramolecular complexes (biomembranes and lipoproteins).

Antioxidant Potential of Aqueous Dispersions of Fullerenes C, C, and Gd@C.

The antioxidant potential (capacity and activity) of aqueous fullerene dispersions (AFD) of non-functionalized C, C, and Gd@C endofullerene (in micromolar concentration range) was estimated based on chemiluminescence measurements of the model of luminol and generation of organic radicals by 2,2'-azobis(2-amidinopropane) dihydrochloride (ABAP). The antioxidant capacity was estimated by the TRAP method, from the concentration of half-suppression, and from the suppression area in the initial period. All three approaches agree and show that the antioxidant capacity of AFDs increased in the order Gd@C < C < C.

Microsomal reductase activity in patients with thyroid neoplasms.

Objective: Cytochrome b5-reductase (CYB5R) and cytochrome P450 reductase (CYPOR) are important for cell metabolism; however, their role in thyroid hormonogenesis and carcinogenesis has not been elucidated yet. The activity of CYB5R correlates with the metastasis in breast cancer, but there are no similar studies for CYB5R and CYPOR for thyroid tumors. The aim of this study was to elucidate the activity of CYB5R and CYPOR changes in benign euthyroid and hyperthyroid neoplasms and in papillary thyroid cancer for their potential application as biomarkers for diagnosis and prognosis prediction of thyroid cancer.

Non-Functionalized Fullerenes and Endofullerenes in Aqueous Dispersions as Superoxide Scavengers.

Endohedral metal fullerene are potential nanopharmaceuticals for MRI; thus, it is important to study their effect on reactive oxygen species (ROS) homeostasis. Superoxide anion radical is one of the key ROS. The reactivity of aqueous dispersions of pristine (non-functionalized) fullerenes and Gd@C endofullerene have been studied with respect to superoxide in the xanthine/xanthine oxidase chemiluminescence system.

Antioxidant Potential of Antiviral Drug Umifenovir.

Free radical reactions play an important role in biological functions of living systems. The balance between oxidants and antioxidants is necessary for the normal homeostasis of cells and organisms. Experimental works demonstrate the role of oxidative stress that is caused by influenza virus as well as the toxic effects of some antiviral drugs.

Towards the surface hydroxyl species in CeO nanoparticles.

Understanding the complex chemistry of functional nanomaterials is of fundamental importance. Controlled synthesis and characterization at the atomic level is essential to gain deeper insight into the unique chemical reactivity exhibited by many nanomaterials. Cerium oxide nanoparticles have many industrial and commercial applications, resulting from very strong catalytic, pro- and anti-oxidant activity.