Bioactive Carbon@CeO Composites as Efficient Antioxidants with Antiamyloid and Radioprotective Potentials.

Blending carbon particles (CPs) and nanoscale bioactive cerium dioxide is a promising approach for designing composites for biomedical applications, combining the sorption and antioxidant potentials of each individual component. To address this issue, it is crucial to assess the correlation between the components' ratio, physicochemical parameters, and biofunctionality of the composites. Thus, the current research was aimed at fabricating C@CeO composites with different molar ratios and the examination of how the parameters of the composites affect their bioactivity.

Design of Magnetic FeO/CeO "Core/Shell"-Like Nanocomposites with Pronounced Antiamyloidogenic and Antioxidant Bioactivity.

"Core/shell" nanocomposites based on magnetic magnetite (FeO) and redox-active cerium dioxide (CeO) nanoparticles (NPs) are promising in the field of biomedical interests because they can combine the ability of magnetic NPs to heat up in an alternating magnetic field (AMF) with the pronounced antioxidant activity of CeO NPs. Thus, this report is devoted to FeO/CeO nanocomposites (NCPs) synthesized by precipitation of the computed amount of "CeO-shell" on the surface of prefabricated FeO NPs. The X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy data validated the formation of FeO/CeO "core/shell"-like NCPs, in which ultrafine CeO NPs with an average size of approximately 3-3.

Biocompatible zeolite-dye composites with anti-amyloidogenic properties.

One of the most attractive approaches in biomedicine and pharmacy is the application of multifunctional materials. The mesoporous structure of clinoptilolite (CZ) absorbs various types of substances and can be used as a model for studying the carriers for targeted drug delivery with controlled release. CZ-dye composites are fabricated by incorporation into clinoptilolite pores commonly used dyes, aluminum phthalocyanine, zinc porphine, and hypericin.

Surface-modified cerium dioxide nanoparticles with improved anti-amyloid and preserved nanozymatic activity.

Cerium dioxide nanoparticles (CeO NPs) are used increasingly in nanotechnology and particularly in biotechnology and bioresearch. Thus, CeO NPs have been successfully tested in vitro as a potential therapeutic agent for various pathologies associated with oxidative stress, including the formation of protein amyloid aggregates. In this study, to increase the anti-amyloidogenic efficiency and preserve the antioxidant potential, the surface of the synthesized CeO NPs is modified with a nonionic, sugar-based surfactant, dodecyl maltoside (DDM), which is known for its high anti-amyloidogenic activity and biocompatibility.

Micelle Formation in Aqueous Solutions of the Cholesterol-Based Detergent Chobimalt Studied by Small-Angle Scattering.

The structure and interaction parameters of the water-soluble cholesterol-based surfactant, Chobimalt, are investigated by small-angle neutron and X-ray scattering techniques. The obtained data are analyzed by a model-independent approach applying the inverse Fourier transformation procedure as well as considering a model fitting procedure, using a core-shell form factor and hard-sphere structure factor. The analysis reveals the formation of the polydisperse spherical or moderately elongated ellipsoidal shapes of the Chobimalt micelles with the hard sphere interaction in the studied concentration range 0.

Cerium dioxide nanoparticles synthesized via precipitation at constant pH: Synthesis, physical-chemical and antioxidant properties.

Cerium oxide nanoparticles (CeO NPs) are well known for their application in various fields of industry, as well as in biology and medicine. Knowledge of synthesis schemes, physicochemical and morphological features of nanoscale CeO is important for assessing their antioxidant behavior and understanding the mechanism of oxidative stress and its consequences. The choice of the method of synthesis should be based on the possibility to choose the conditions and parameters for obtaining CeO with controlled dimensions and a ratio of Се/Се on their surface.

The intriguing dose-dependent effect of selected amphiphilic compounds on insulin amyloid aggregation: Focus on a cholesterol-based detergent, Chobimalt.

The amyloidogenic self-assembly of many peptides and proteins largely depends on external conditions. Among amyloid-prone proteins, insulin attracts attention because of its physiological and therapeutic importance. In the present work, the amyloid aggregation of insulin is studied in the presence of cholesterol-based detergent, Chobimalt.

Dual-Functional Antioxidant and Antiamyloid Cerium Oxide Nanoparticles Fabricated by Controlled Synthesis in Water-Alcohol Solutions.

Oxidative stress is known to be associated with a number of degenerative diseases. A better knowledge of the interplay between oxidative stress and amyloidogenesis is crucial for the understanding of both, aging and age-related neurodegenerative diseases. Cerium dioxide nanoparticles (CeO NPs, nanoceria) due to their remarkable properties are perspective nanomaterials in the study of the processes accompanying oxidative-stress-related diseases, including amyloid-related pathologies.

Monitoring the surface tension by the pendant drop technique for detection of insulin fibrillogenesis.

Monitoring the aggregation of amyloid-prone proteins is critical for understanding the mechanism of amyloid fibril formation. Insulin, when dissolved in low pH buffer, has a surface tension of 61-64 mN m, as measured by the pendant drop technique. Formation of insulin amyloid fibrils resulted in the increase of the surface tension values up to 71.

Structural and physical-chemical characterization of redox active CeOnanoparticles synthesized by precipitation in water-alcohol solutions.

A set of cerium dioxide nanoparticles (CeONPs) was synthesized by precipitation in water-alcohol solutions under conditions when the physical-chemical parameters of synthesized NPs were controlled by changing the ratio of the reaction components. The size of CeONPs is controlled largely by the dielectric constant of the reaction solution. An increase of the percentage of Ceions at the surface was observed with a concomitant reduction of the NP sizes.

Development of multifunctional nanocomposites for controlled drug delivery and hyperthermia.

Magnetic nano/micro-particles based on clinoptilolite-type of natural zeolite (CZ) were fabricated and were expected to act as carriers for controlled drug delivery/release, imaging and local heating in biological systems. Adsorption of rhodamine B, sulfonated aluminum phthalocyanine and hypericin by magnetic CZ nano/micro-particles was investigated, as was the release of hypericin. Using an alternating magnetic field, local temperature increase by 10 °C in animal tissue with injected magnetic CZ particles was demonstrated.

The Interplay among Subunit Composition, Cardiolipin Content, and Aggregation State of Bovine Heart Cytochrome Oxidase.

Mitochondrial cytochrome oxidase (CcO) is a multisubunit integral membrane complex consisting of 13 dissimilar subunits, as well as three to four tightly bound molecules of cardiolipin (CL). The monomeric unit of CcO is able to form a dimer and participate in the formation of supercomplexes in the inner mitochondrial membrane. The structural and functional integrity of the enzyme is crucially dependent on the full subunit complement and the presence of unperturbed bound CL.

Complementary experimental and computational analysis of the effects of non-ionic detergents and phospholipids on insulin amyloid aggregation.

Amphiphilic compounds, both detergents and lipids, are important tools for in vitro analysis of water-soluble and integral membrane proteins. A key question is whether these two groups of amphiphilic molecules use the same pathway to affect structural and functional integrity of proteins. In the present study, we tested the effect of non-ionic detergent dodecyl maltoside (DDM), two phospholipids, 1,2-dimyristoyl-sn-glycero-3- phosphocholine (DMPC), 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC), and the detergent-phospholipid mixtures on insulin amyloidogenesis in vitro.

Fullerenes as an Effective Amyloid Fibrils Disaggregating Nanomaterial.

Nowadays, determining the disassembly mechanism of amyloids under nanomaterials action is a crucial issue for their successful future use in therapy of neurodegenerative and overall amyloid-related diseases. In this study, the antiamyloid disassembly activity of fullerenes C and C dispersed in 1-methyl-2-pyrrolidinone (NMP) toward amyloid fibrils preformed from lysozyme and insulin was investigated using a combination of different experimental techniques. Thioflavin T fluorescence assay and atomic force microscopy were applied for monitoring of disaggregation activity of fullerenes.

Advances in the Study of Cerium Oxide Nanoparticles: New Insights into Antiamyloidogenic Activity.

There seems to be general agreement that oxidative stress is involved in many pathological conditions including Parkinson's, Alzheimer's, and other neurodegenerative diseases, and overall aging. Cerium oxide nanoparticles, also known as nanoceria (CeO-NPs), have shown promise as catalytic antioxidants, based on their ability to switch between Ce and Ce valence states. In the present work we have synthesized and characterized CeO-NPs, examined the effect of CeO-NPs on amyloidogenesis of insulin, and analyzed the impact of CeO-NPs on oxidative stress and biocompatibility in three types of invasive cancer cells, and in the preclinical model of the chorioallantoic membrane (CAM) of quail embryos.

Dual effect of non-ionic detergent Triton X-100 on insulin amyloid formation.

Atomic force microscopy, Thioflavin T (ThT) fluorescence assay, circular dichroism spectroscopy, differential scanning calorimetry, and molecular modeling techniques have been employed to investigate the amyloid aggregation of insulin in the presence of non-ionic detergent, Triton X-100 (TX-100). In contrast to recently described inhibition of lysozyme amyloid formation by non-ionic detergents (Siposova, 2017), the amyloid aggregation of insulin in the presence of sub-micellar TX-100 concentration exhibits two dissimilar phases. The first, inhibition phase, is observed at the protein to detergent molar ratio of 1:0.

Inhibition of amyloid fibril formation and disassembly of pre-formed fibrils by natural polyphenol rottlerin.

Natural polyphenols, curcumin, rottlerin and EGCG were selected for initial computational modeling of protein-ligand interaction patterns. The docking calculations demonstrated that these polyphenols can easily adjust their conformational shape to fit well into the binding sites of amyloidogenic proteins. The experimental part of the study focused on the effect of rottlerin on fibrillation of three distinct amyloidogenic proteins, namely insulin, lysozyme and Aβ peptide.

Inhibition of lysozyme amyloidogenesis by phospholipids. Focus on long-chain dimyristoylphosphocholine.

Background: Protein amyloid aggregation is an important pathological feature of a group of different degenerative human diseases called amyloidosis. We tested effect of two phospholipids, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) on amyloid aggregation of hen egg white (HEW) lysozyme in vitro.

Methods: Effect of phospholipids was investigated using spectroscopic techniques (fluorescence and CD spectroscopy), atomic force microscopy and image analysis.

Interaction of nonionic detergents with the specific sites of lysozyme amyloidogenic region - inhibition of amyloid fibrillization.

Two nonionic detergents, Triton X-100 (TX-100) and n-dodecyl-β-d-maltoside (DDM) were tested for their ability to affect lysozyme amyloid aggregation. We have demonstrated that fibrillization of lysozyme is completely inhibited by low sub-micellar concentrations of both of these detergents. The apparent IC values were calculated to be 22μM and 26μM for TX-100 and DDM, respectively.

Subunit analysis of mitochondrial cytochrome c oxidase and cytochrome bc by reversed-phase high-performance liquid chromatography.

A rapid separation of the ten nuclearly-encoded subunits of mitochondrial cytochrome c oxidase, and ten out of the eleven subunits of cytochrome bc, was achieved using a short, 50 mm C-reversed-phase column. The short column decreased the elution time 4-7 fold while maintaining the same resolution quality. Elution was similar to a previously published protocol, i.

Functional and structural evaluation of bovine heart cytochrome c oxidase incorporated into bicelles.

Bilayered long- and short-chain phospholipid assemblies, known as bicelles, have been widely used as model membranes in biological studies. However, to date, there has been no demonstration of structural or functional viability for the fundamental mitochondrial electron transport complexes reconstituted into or interacting with bicelles. In the present work, bicelles were formed from the mixture of long- and short-chain phospholipids, specifically 14:0 and 6:0 phosphatidylcholines (1,2-dimyristoyl-sn-glycero-3-phosphocholine, (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine, (DHPC)).