Improving Nanozyme-Based Colorimetric Assays through Medium Composition Optimization in Nanozyme-Substrate Reaction.

Nanozymes, while promising alternatives to natural peroxidases in colorimetric assays, are often hindered by lower catalytic efficiencies. Although numerous approaches have been developed to improve signal intensity in nanozyme-based assays, optimization of the reaction medium in which the nanozyme interacts with the substrate remains a significantly underexplored area. The vast majority of studies rely on standard sodium acetate buffers or commercially sourced reagents optimized for horseradish peroxidase, neglecting the unique catalytic properties of different nanozymes.

The development of a method to produce diagnostic reagents using LaNiO nanospheres and their application in nanozyme-linked immunosorbent assay for the colorimetric screening of C-reactive protein with high sensitivity.

LaNiO perovskite nanoparticles, especially nanospheres (LNNS), show great promise in biomedical assays due to their peroxidase-like catalytic properties. However, LNNS-based diagnostic reagents have not been tested in nanozyme enzyme-linked immunosorbent assay (NLISA) or other enzyme-linked immunosorbent assays, and there is limited data on their synthesis. To fill this gap, it is necessary to develop a method for creating LNNS conjugates with monoclonal antibodies and to investigate the reproducibility, scalability, and applicability of these diagnostic reagents in NLISA.

Effect of Short Peptides of Pregnancy-Specific β1-Glycoprotein on Differentiation of Human Regulatory T Cells In Vitro and on Their Cytokine Profile.

Pregnancy-specific β1-glycoprotein (PSG), one of the most important proteins of pregnancy, has a pronounced immunosuppressive effect. Short peptides of PSG, the so-called SLiMs (short linear motifs), are promising molecules for mild immunosuppression. We studied in vitro effect of short PSG peptides (YACS, YQCE, YVCS, and YECE) on differentiation and cytokine profile of human T-regulatory lymphocytes (Treg).

Development and performance of NLISA for C-reactive protein detection based on Prussian blue nanoparticle conjugates.

Prussian blue nanoparticles (PBNPs), also called nanozymes, are very attractive as an alternative to horseradish peroxidase in immunoassay development due to their simple and low-cost synthesis, stability and high catalytic activity. Today, there is a method for highly effective PBNP synthesis based on the reduction of an FeCl/K[Fe(CN)] mixture by hydrogen peroxide. However, there is a lack of research showcasing the use of these highly effective PBNPs for specific target detection in clinical settings, as well as a lack of comprehensive comparisons with conventional methods.

Effect of PEGylated Graphene Oxide Nanoparticles on the Metabolism of Jurkat Cells.

The effect of graphene oxide (GO) nanoparticles of 100-200 nm in size coated with linear (LP-GO) and branched (BP-GO) polyethylene glycol at concentrations of 5 and 25 μg/mL on the metabolism of Jurkat tumor cells was studied. It was found that LP-GO nanoparticles at a concentration of 25 μg/mL can enhance basal glycolysis of Jurkat T-lymphocyte tumor cell line cells, while LP-GO and BP-GO at the same concentration can reduce the indicators of compensatory glycolysis. Despite this, GO nanoparticles coated with linear and branched PEG at a concentration of 5 μg/mL do not have pronounced effects on oxidative phosphorylation and glycolysis of Jurkat cells and could therefore be safe for activated T cells.

Optimizing the Composition of the Substrate Enhances the Performance of Peroxidase-like Nanozymes in Colorimetric Assays: A Case Study of Prussian Blue and 3,3'-Diaminobenzidine.

One of the emerging trends in modern analytical and bioanalytical chemistry involves the substitution of enzyme labels (such as horseradish peroxidase) with nanozymes (nanoparticles possessing enzyme-like catalytic activity). Since enzymes and nanozymes typically operate through different catalytic mechanisms, it is expected that optimal reaction conditions will also differ. The optimization of substrates for nanozymes usually focuses on determining the ideal pH and temperature.

Vertical Flow Immunoassay Based on Carbon Black Nanoparticles for the Detection of IgG against SARS-CoV-2 Spike Protein in Human Serum: Proof-of-Concept.

Point-of-care tests play an important role in serological diagnostics of infectious diseases and post-vaccination immunity monitoring, including in COVID-19. Currently, lateral flow tests dominate in this area and show good analytical performance. However, studies to improve the effectiveness of such tests remain important.

Interaction of Graphene Oxide Nanoparticles with Human Mesenchymal Stem Cells Visualized in the Cell-IQ System.

Graphene oxide is a promising nanomaterial with many potential applications. However, before it can be widely used in areas such as drug delivery and medical diagnostics, its influence on various cell populations in the human body must be studied to ensure its safety. We investigated the interaction of graphene oxide (GO) nanoparticles with human mesenchymal stem cells (hMSCs) in the Cell-IQ system, evaluating cell viability, mobility, and growth rate.

The Effect of PEGylated Graphene Oxide Nanoparticles on the Th17-Polarization of Activated T Helpers.

We investigated the direct effect of PEGylated graphene oxide (P-GO) nanoparticles on the differentiation, viability, and cytokine profile of activated T helper type 17 (Th17) in vitro. The subject of the study were cultures of "naive" T-helpers (CD4+) isolated by immunomagnetic separation and polarized into the Th17 phenotype with a TCR activator and cytokines. It was found that P-GO at low concentrations (5 µg/mL) had no effect on the parameters studied.

The Role of Recombinant Glycodelin in the Differentiation of Regulatory T-Lymphocytes.

The effect of recombinant glycodelin (GdA) on the number of T-regulatory lymphocytes (Treg) in a culture of activated CD4 lymphocytes was investigated, while simultaneously assessing the proliferative status of the cells. Recombinant GdA from E. coli and from HEK293 cells were used in the study at concentrations of 0.

Prussian Blue Nanozymes with Enhanced Catalytic Activity: Size Tuning and Application in ELISA-like Immunoassay.

Prussian blue nanozymes possessing peroxidase-like activity gather significant attention as alternatives to natural enzymes in therapy, biosensing, and environmental remediation. Recently, Prussian blue nanoparticles with enhanced catalytic activity prepared by reduction of FeCl/K[Fe(CN)] mixture have been reported. These nanoparticles were denoted as 'artificial peroxidase' nanozymes.

Interaction of Graphene Oxide Modified with Linear and Branched PEG with Monocytes Isolated from Human Blood.

Multiple graphene-based therapeutics have recently been developed, however potential risks related to the interaction between nanomaterials and immune cells are still poorly understood. Therefore, studying the impact of graphene oxide on various populations of immune cells is of importance. In this work, we aimed to investigate the effects of PEGylated graphene oxide on monocytes isolated from human peripheral blood.

Graphene Oxide Nanoparticels Interaction with Jurkat Cell Line in Cell-IQ System.

In recent years, materials based on graphene oxide (GO) have been actively studied for their use in biomedicine. The aim of our study was to investigate the increase in cell mass and viability of Jurkat tumor line T cells during 24 h of contact with GO nanoparticles in the Cell-IQ system of intravital observation. We used nanoparticles of different sizes coated with linear or branched polyethylene glycol (PEG) at concentrations of 5 and 25 μg/mL.

Modified Desolvation Method Enables Simple One-Step Synthesis of Gelatin Nanoparticles from Different Gelatin Types with Any Bloom Values.

Gelatin nanoparticles found numerous applications in drug delivery, bioimaging, immunotherapy, and vaccine development as well as in biotechnology and food science. Synthesis of gelatin nanoparticles is usually made by a two-step desolvation method, which, despite providing stable and homogeneous nanoparticles, has many limitations, namely complex procedure, low yields, and poor reproducibility of the first desolvation step. Herein, we present a modified one-step desolvation method, which enables the quick, simple, and reproducible synthesis of gelatin nanoparticles.

Measuring the concentration of protein nanoparticles synthesized by desolvation method: Comparison of Bradford assay, BCA assay, hydrolysis/UV spectroscopy and gravimetric analysis.

The desolvation technique is one of the most popular methods for preparing protein nanoparticles for medicine, biotechnology, and food applications. We fabricated 11 batches of BSA nanoparticles and 2 batches of gelatin nanoparticles by desolvation method. BSA nanoparticles from 2 batches were cross-linked by heating at +70 °C for 2 h; other nanoparticles were stabilized by glutaraldehyde.

Nuclear magnetic resonance immunoassay of tetanus antibodies based on the displacement of magnetic nanoparticles.

A nuclear magnetic resonance (NMR) immunoassay based on the application of carbon-coated iron nanoparticles conjugated with recognition molecules was designed. The principle of the assay is that ELISA plates are coated with a capture element, and then an analyte is added and detected by conjugating the magnetic nanoparticles with recognition molecules. Afterwards, the elution solution (0.

The effects of human pregnancy-specific β1-glycoprotein preparation on Th17 polarization of CD4 cells and their cytokine profile.

Background: Pregnancy-specific β1-glycoproteins are capable of regulating innate and adaptive immunity, exerting predominantly suppressive effects. In this regard, they are of interest in terms of their pharmacological potential for the treatment of autoimmune diseases and post-transplant complications. The effect of these proteins on the main pro-inflammatory subpopulation of T lymphocytes, IL-17-producing helper T cells (Th17), has not been comprehensively studied.

Solid-phase nuclear magnetic resonance immunoassay for the prostate-specific antigen by using protein-coated magnetic nanoparticles.

A solid phase NMR-based sandwich immunoassay for the prostate-specific antigen (PSA) is presented. Carbon-encapsulated iron nanoparticles were functionalized with bovine serum albumin, coupled to monoclonal antibodies, and then used as magnetic labels. A nitrocellulose membrane with 8-μm pores was coated with capture antibodies and subsequently incubated with a serum sample and a suspension of the nanoconjugate.

Magnetic Nanoclusters Coated with Albumin, Casein, and Gelatin: Size Tuning, Relaxivity, Stability, Protein Corona, and Application in Nuclear Magnetic Resonance Immunoassay.

The surface functionalization of magnetic nanoparticles improves their physicochemical properties and applicability in biomedicine. Natural polymers, including proteins, are prospective coatings capable of increasing the stability, biocompatibility, and transverse relaxivity (r2) of magnetic nanoparticles. In this work, we functionalized the nanoclusters of carbon-coated iron nanoparticles with four proteins: bovine serum albumin, casein, and gelatins A and B, and we conducted a comprehensive comparative study of their properties essential to applications in biosensing.

[The role of alpha-fetoprotein in regulation of the cytokine profile of activated T-helpers and their conversion in Th17 phenotype].

We studied the effect of the native (non-recombinant) alpha-fetoprotein (AFP) on differentiation, proliferation, and cytokine profile of activated helper T cells 17 (Th17). The object of the study was a culture of isolated by immunomagnetic separation helper T cells (CD4+), induced into the Th17 phenotype by using TCR-activator and proinflammatory cytokines (IL-1β and IL-6). AFP had not significant effect on the frequency of Th17 cells (ROR-γτ+) in the helper T cell culture, and did not affect proliferation of these cells, as measured by Ki-67 expression.

Development of an Immunosorbent for Solid-Phase NMR-Based Assay.

The conditions for constructing an immunosorbent reagent for solid-phase NMR analysis were optimized. For this purpose, we increased the area of ​​the sensitized portion of the membrane to fit the relaxometer coil size and added the agent sorption buffer. This provided the penetration of the anti-ligand molecules into the membrane thickness and their uniform distribution.

Conjugation of carbon coated-iron nanoparticles with biomolecules for NMR-based assay.

In this work, we developed and optimized conjugates of carbon-coated iron nanoparticles (Fe@C) with streptavidin and monoclonal antibodies. The conjugation procedure included two stages. First, amino groups were grafted onto the carbon shell to facilitate noncovalent sorption of bovine serum albumin (BSA).

α-Fetoprotein Influence on the Conversion of Naïve T-Helpers into Memory T-Cell Effector Subpopulations.

The effect of native α-fetoprotein (AFP) on the conversion of naïve T-helpers into central memory T-cells (TCM) and effector subpopulations of the preterminally differentiated (TEM) and terminally differentiated (TEMRA) memory T-cells was studied. AFP was found to prevent the conversion of naïve T-helpers into effector subpopulations of memory T cells (TEM and TEMRA) while reducing the total production of IL-4 and IFN-γ by the studied cell populations. The data reveal a new role of AFP in the immune tolerance formation during pregnancy.

Highly Stable Conjugates of Carbon Nanoparticles with DNA Aptamers.

Conjugates of carbon nanoparticles and aptamers have great potential in many areas of biomedicine. In order to be implemented in practice, such conjugates should keep their properties throughout long storage period in commonly available conditions. In this work, we prepared conjugates of carbon nanoparticles (CNP) with DNA aptamers using streptavidin-biotin reaction.

[The influence of chorionic gonadotropin on phenotype conversion and hTERT gene expression by T-lymphocytes of different degrees of differentiation].

The effects of chorionic gonadotropin (hCG) on the expression of the hTERT gene in combination with the conversion of the phenotype of naive T-cells and T-cells of immune memory in vitro were studied. hCG inhibited expression of hTERT mRNA in naive T-cells (CD45RA+) and immune memory T cells (CD45RO+), causing a decrease in the replicative potential of the cells. The presence of hCG in the culture led to the conversion of the phenotype of T-lymphocytes.