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Essential oils (EOs) are reported to be natural pesticides, but their use to protect crops is very limited due to EOs' high instability and great volatility. Nanovectors represent a very smart alternative, and in this study, EOs from Artemisia annua (AEO) and Salvia fruticosa (SEO) were formulated into microemulsions and tested against Fusarium verticillioides. The EOs were extracted by steam distillation and analyzed by GC–MS. The main constituents of AEO were camphor, artemisia ketone, and 1,8-cineole; the main constituents of SEO were 1,8-cineole, camphor, α-pinene, and β-pinene. Artemisia ketone and 1,8-cineole were used to calculate the recovery and chemical stability of the microemulsions. The microemulsions were loaded with 10 mg/mL of EOs, and the recoveries were 99.8% and 99.6% for AEO and SEO, respectively. The sizes of the lipid phases were 255.3 ± 0.6 nm and 323.7 ± 2.3 nm for the AEO and SEO microemulsions, respectively. Activity against F. verticillioides was tested using amphotericin B as the positive control. F. verticillioides was very susceptible to both EOs. When loaded in the microemulsions, AEO and SEO remained very active at a dose of 1.4 and 1.2 mg, with a 99.99% reduction of F. verticillioides. The findings suggest AEO and SEO microemulsions are suitable carriers for the protection of crops against F. verticillioides. [ABSTRACT FROM AUTHOR]

Based on the generalized results of experimental methods for studying the viscosity of oligomers—DSC, electron microscopy, NMR spin echo, x‐ray diffraction analysis, edge wetting angles, laser microinterference, atomic force microscopy, dynamic light scattering, plastic flow—an analysis of the features of the supramolecular organization of melts and solutions of epoxy oligomers was carried out. In terms of thermofluctuation approach, a qualitative assessment of the structural elements forming a macroscopic polymer body is given, and direct morphological evidence of their structure, thermodynamic stability, size evolution with temperature changes and elastic‐strain effects is presented. A mathematical apparatus has been developed to describe the destruction of domains in solutions and melts of oligomers. Analytical equations have been proposed for calculating the time of thermofluctuation relaxation of domains. Based on the analysis of the supramolecular structure of dian epoxy oligomers by transmission electron microscopy and translational mobility of oligomer macromolecules in the high temperature region (Tg + 150°C), it has been suggested that a structure such as "flickering clusters" of free volume elements is formed in the oligomer melts. Highlights: Phase diagrams of aromatic and aliphatic epoxy oligomers have been constructed.The influence of molecular weight on the activation energy of diffusion of viscous flow is estimated.It has been shown that the supramolecular structure of epoxy oligomers in the melt contains "flickering clusters."The lifetime of density fluctuations of epoxy oligomers domains in melts has been calculated. [ABSTRACT FROM AUTHOR]

In this study, the interaction of antimicrobial peptide Maximin 3 (Max3) with three different lipid bilayer models was investigated to gain insight into its mechanism of action and membrane specificity. Bilayer perturbation assays using liposome calcein leakage dose–response curves revealed that Max3 is a selective membrane‐active peptide. Dynamic light scattering recordings suggest that the peptide incorporates into the liposomal structure without producing a detergent effect. Langmuir monolayer compression assays confirmed the membrane inserting capacity of the peptide. Attenuated total reflection‐Fourier transform infrared spectroscopy showed that the fingerprint signals of lipid phospholipid hydrophilic head groups and hydrophobic acyl chains are altered due to Max3‐membrane interaction. On the other hand, all‐atom molecular dynamics simulations (MDS) of the initial interaction with the membrane surface corroborated peptide‐membrane selectivity. Peptide transmembrane MDS shed light on how the peptide differentially modifies lipid bilayer properties. Molecular mechanics Poisson–Boltzmann surface area calculations revealed a specific electrostatic interaction fingerprint of the peptide for each membrane model with which they were tested. The data generated from the in silico approach could account for some of the differences observed experimentally in the activity and selectivity of Max3. [ABSTRACT FROM AUTHOR]

Pharmaceutical formulations are increasingly based on drug nanoparticles or carrier nanoparticles encapsulating drugs or mRNA molecules. Sizes and monodispersity of the nanoparticles regulate bioavailability, pharmacokinetics and pharmacology. Microfluidic mixers promise unique conditions for their continuous preparation. A novel microfluidic antisolvent precipitation device was realized by two-photon-polymerization with a mixing channel in which the organic phase formed a sheet with a homogeneous thickness of down to 7 μm completely wrapped in the aqueous phase. Homogeneous diffusion through the sheet accelerates mixing. Optical access was implemented to allow in-situ dynamic light scattering. By centering the thin sheet in the microchannel cross-section, two important requirements are met. On the one hand, the organic phase never reaches the channel walls, avoiding fouling and unstable flow conditions. On the other hand, in the sheet positioned at the maximum of the parabolic flow profile the nanoparticle velocities are homogenized which enables flow-compensated Dynamic Light Scattering (flowDLS). These unique features allowed in-situ particle size determination for the first time. Monitoring of lipid nanoparticle precipitation was demonstrated for different rates of solvent and antisolvent flows. This breakthrough innovation will not only enable feedback control of nanoparticle production but also will provide new insights into the dynamics of nanoparticle precipitation. [ABSTRACT FROM AUTHOR]

In this investigation, we explored the microrheological characteristics of dilute hydrogels composed exclusively of Poly(vinyl) alcohol (PVA), Phytagel (PHY), and a blend of the two in varying concentrations. Each of these polymers has established applications in the biomedical field, such as drug delivery and lens drops. This study involved varying the sample concentrations from 0.15% to 0.3% (w/w) to assess how the concentration influenced the observed rheological response. Two probe sizes were employed to examine the impact of the size and verify the continuity hypothesis. The use of two polymer blends revealed their immiscibility and tendency to undergo phase separation, as supported by the existing literature. Exploring the microrheological structure is essential for a comprehensive understanding of the molecular scale. Dynamic light scattering (DLS) was chosen due to its wide frequency range and widespread availability. The selected dilute concentration range was hypothesized to fall within the transition from an ergodic to a non-ergodic medium. Properly identifying the sample's nature during an analysis—whether it is ergodic or not—is critical, as highlighted in the literature. The obtained results clearly demonstrate an overlap in the results for the storage (G') and loss moduli (G″) for the different probe particle sizes, confirming the fulfillment of the continuum hypothesis. [ABSTRACT FROM AUTHOR]

Electroconvection in kerosene-based magnetic fluids was experimentally studied using the method of dynamic light scattering. A decrease in the relaxation time of the autocorrelation function was discovered at various voltages and interelectrode distances. Based on experimental data, the dependences of the maximum velocity of chaotic electroconvective flows on the voltage on the electrodes and the distance between them were determined. [ABSTRACT FROM AUTHOR]

The Zika virus (ZIKV) is a global health threat due to its rapid spread and severe health implications, including congenital abnormalities and neurological complications. Differentiating ZIKV from other arboviruses such as dengue virus (DENV) is crucial for effective diagnosis and treatment. This study presents the development of a biosensor for detecting the ZIKV non‐structural protein 1 (NS1) using gold nanoparticles (AuNPs) functionalized with monoclonal antibodies employing dynamic light scattering (DLS). The biosensor named ZINS1‐mAb‐AuNP exhibited specific binding to the ZIKV NS1 protein, demonstrating high colloidal stability indicated by a hydrodynamic diameter (DH) of 140 nm, detectable via DLS. In the absence of the protein, the high ionic strength medium caused particle aggregation. This detection method showed good sensitivity and specificity, with a limit of detection (LOD) of 0.96 μg mL−1, and avoided cross‐reactivity with DENV2 NS1 and SARS‐CoV‐2 spike proteins. The ZINS1‐mAb‐AuNP biosensor represents a promising tool for the early and accurate detection of ZIKV, facilitating diagnostic and treatment capabilities for arboviral infections. [ABSTRACT FROM AUTHOR]

In physical foaming processes of thermoplastics, a liquid mixture consisting of a molten polymer with a dissolved blowing agent is extruded through a die or injected into a mold. The morphology of the foam matrix strongly depends on the mutual diffusion coefficient D11 of the liquid polymer-blowing agent mixture. For a better understanding of the underlying physical mechanisms during the foaming process and the development of corresponding models, accurate knowledge of D11 is needed. This work reports on the simultaneous measurement of D11 and the thermal diffusivity a of liquid mixtures consisting of polystyrene melts with dissolved nitrogen (N2) or carbon dioxide (CO2) at mass fractions wsolute up to 0.003 or 0.02 and temperatures T between (433 and 533) K using dynamic light scattering (DLS). The determined D11 range is between (1 and 4) × 109 m2⋅s−1 and are slightly larger for the mixtures containing N2 at a given T and wsolute. D11 could be determined with an average expanded relative uncertainty of 18%. Considering all investigated state points and the achieved experimental uncertainties, both D11 and a are independent on the amount of dissolved gas, despite relatively large mole fractions of the dissolved blowing agents xsolute of 0.997 and 0.93. [ABSTRACT FROM AUTHOR]

Aqueous two-phase systems (ATPSs) are formed when two nonionic polymers, or a single polymer and salt, are mixed in water above a specific concentration, resulting in the emergence of phase separation and the formation of two immiscible aqueous phases. The solvent properties of the aqueous media within the phases of ATPSs rely on the specific composition of the co-solutes and the arrangement of the hydrogen bond network within each phase. Here, we investigate the anion effect of various sodium salts on the enhancement or destabilization of polyethylene glycol (PEG)–salt ATPS formation. Relatively small changes in ATPS ionic composition were shown to result in significant changes in solute partitioning. Additionally, we previously established that the arrangement of hydrogen bonds within the coexisting phases of ATPSs is different, as evidenced by Attenuated Total Reflection—Fourier Transform Infrared (ATR-FTIR) spectroscopic analysis of OH-stretch bands. The hydrogen bond arrangement was shown to abruptly change at concentrations below the threshold of macroscopic phase separation in the ATPSs. Using dynamic light scattering (DLS), we observed a correlation between these abrupt changes in H-bond arrangement and the detection of agglomerate formation in both polymer–polymer and polymer–salt systems. [ABSTRACT FROM AUTHOR]

Recently, environmentally acceptable lubricants (EALs) developed from vegetable oils are more widely used in the field of lubrication technology as an alternative to mineral and synthetic oils. The homogeneous and long-term stability of additives in base lubricants is a crucial requirement for potential applications of vegetable oil-based ionanolubricants (INLs). In this study, the INLs have been formulated with two vegetable oils, rice bran oil and sesame oil containing TiO2 nanoparticles (NPs) and two ionic liquids IL1, 1-ethyl 3-methylimidazolium dicyanamide [EMIM][DCN] and IL2, trihexyltetradecylphosphonium bis(24,4-trimethylpentyl) phosphinate ([P66614][BTMPP]) with surfactants. The main objective is to find the suitable surfactant among sodium dodecyl sulfate (SDS), Tween 20 (T-20), and Triton X-100 (TX-100) and its optimum additives to surfactant ratio. Dispersion stability of INLs has been investigated by using visual monitoring and dynamic light scattering. The analysis showed that additives start agglomeration and make larger clusters on the 10th and 20th days of formulation, respectively. On the 30th day of formulation, the larger clusters settle down in the bottom due to gravity. However, in spite of this pattern, the additives remain stable in vegetable oils at particular optimum additives to surfactant ratio. Four stable samples were recorded on the basis of dispersion stability analysis. Rice bran oil and IL1-based INLs having additives to TX-100 of 1:2 have found long-term stability. Additives to SDS ratios of 1:6 was found optimum for rice bran oil and IL2-based INLs. Similarly, for sesame oil-based INLs, the additives to T-20 ratios of 1:4 and 1:2 are found optimum for IL1 and IL2, respectively. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) have recently become an important object of studies. It seems that, in the body, intercellular communication, including the regulation of gene expression, the control of proliferation and differentiation, and others, is mediated by EVs. The important role of EVs in pathology is also shown. An important practical application of EVs is their use as markers of various pathological conditions. At present, the understanding of the molecular mechanisms of action of EVs is very limited, not least due to the methodological difficulties of studying these objects. First of all, it should be noted that there is no standardized method for isolating EVs, and this is a problem for a deeper study of EVs. We tried to choose the most appropriate method for isolating EVs from blood serum. For this, EVs were isolated from blood serum using three methods, after which the protein composition of the isolated EVs was determined using mass spectrometry. Each of the methods used has its own advantages and disadvantages, which must be taken into account when planning experiments in the future. [ABSTRACT FROM AUTHOR]

Abstract Pharmaceutical formulations are increasingly based on drug nanoparticles or carrier nanoparticles encapsulating drugs or mRNA molecules. Sizes and monodispersity of the nanoparticles regulate bioavailability, pharmacokinetics and pharmacology. Microfluidic mixers promise unique conditions for their continuous preparation. A novel microfluidic antisolvent precipitation device was realized by two-photon-polymerization with a mixing channel in which the organic phase formed a sheet with a homogeneous thickness of down to 7 μm completely wrapped in the aqueous phase. Homogeneous diffusion through the sheet accelerates mixing. Optical access was implemented to allow in-situ dynamic light scattering. By centering the thin sheet in the microchannel cross-section, two important requirements are met. On the one hand, the organic phase never reaches the channel walls, avoiding fouling and unstable flow conditions. On the other hand, in the sheet positioned at the maximum of the parabolic flow profile the nanoparticle velocities are homogenized which enables flow-compensated Dynamic Light Scattering (flowDLS). These unique features allowed in-situ particle size determination for the first time. Monitoring of lipid nanoparticle precipitation was demonstrated for different rates of solvent and antisolvent flows. This breakthrough innovation will not only enable feedback control of nanoparticle production but also will provide new insights into the dynamics of nanoparticle precipitation.

Fullerene molecules have been intensively studied over the past few decades due to their unique chemical and physical properties, which have great potential in a wide range of applications. In this article, the formation and aging of C60 colloids in the xylene/ethanol system is considered. The peculiarities of these processes are studied by the methods of refractometry, optical absorption, Raman spectroscopy and dynamic light scattering (DLS). It has been experimentally established that the formation of colloidal particles in a C60/xylene/ethanol mixture depends on the volume content of the components and the storage time of the solution. The time required to achieve stability of self-organization of solute molecules in a C60/xylene/ethanol mixture is discussed. [ABSTRACT FROM AUTHOR]

Aqueous two-phase systems (ATPSs) are formed when two nonionic polymers, or a single polymer and salt, are mixed in water above a specific concentration, resulting in the emergence of phase separation and the formation of two immiscible aqueous phases. The solvent properties of the aqueous media within the phases of ATPSs rely on the specific composition of the co-solutes and the arrangement of the hydrogen bond network within each phase. Here, we investigate the anion effect of various sodium salts on the enhancement or destabilization of polyethylene glycol (PEG)–salt ATPS formation. Relatively small changes in ATPS ionic composition were shown to result in significant changes in solute partitioning. Additionally, we previously established that the arrangement of hydrogen bonds within the coexisting phases of ATPSs is different, as evidenced by Attenuated Total Reflection—Fourier Transform Infrared (ATR-FTIR) spectroscopic analysis of OH-stretch bands. The hydrogen bond arrangement was shown to abruptly change at concentrations below the threshold of macroscopic phase separation in the ATPSs. Using dynamic light scattering (DLS), we observed a correlation between these abrupt changes in H-bond arrangement and the detection of agglomerate formation in both polymer–polymer and polymer–salt systems.

Background and Objectives: The development of resistance of microorganisms to existing antibacterial agents requires constant updating of existing drugs and research in the search for alternative sources of active substances. In recent years, the problem of the emergence of microorganisms resistant to all existing antimicrobial drugs has become systematic and requires significant attention from researchers to search for alternative sources of active substances. The main problem in the development of drugs based on antimicrobial peptides is the search for optimal solutions in the preparation of these substances. Therefore, optimization and search for methods of isolation, analysis and control of protein fractions of water-soluble peptides used for the subsequent development of antibacterial drugs based on them is an urgent task. Materials and Methods: Optimal conditions and methods have been selected for the preparative production of water-soluble peptides isolated from the biomass of Hermetia illucens larvae. Optimization and search of methods for isolation, analysis and control of protein fractions of these water-soluble peptides will ensure the accuracy of the results and obtain optimal amounts of protein fractions. Results: It has been found that the use of molecular sieves makes it possible to obtain a mixture of three peptides with a difference in chromatographic retention time of less than 1 minute, which has been confirmed by three parallel experiments on the isolation and purification of peptides. During HPLC it has been noted that protein fractions 1 and 2 have similar values and the first and third protein fractions have a smaller difference in retention time, which is why there is no complete separation of these chromatographic peaks. Comparison of the percentage of the area of the peptides obtained allows us to talk about the possibility of obtaining peptides of the same size from H. illucens larvae by HPLC, and in combination with DLS to obtain protein fractions with very similar physicochemical and physical characteristics, since this type of chromatography separates substances according to their size. Conclusion: The use of high-performance liquid chromatography makes it possible to establish the reproducibility of the method of isolation of antimicrobial peptides by cold extraction with water and further stages of protein purification, salting and molecular sieve chromatography, which, in correlation with DLS analysis, makes it possible to reliably identify the peptides obtained, and the developed technology of isolation and purification makes it possible to produce these proteins on an industrial scale at low cost.

AbstractWe use the dynamic light scattering technique (DLS) to study the dynamic behavior of complex constituted by weakly charged microemulsion in the presence of polyelectrolyte. We investigated the impact of adding oppositely charged polyacid (PAA), which is a pH-dependent polyelectrolyte, on the dynamics of charged microemulsion nanodroplets in an acidic medium at pH = 4.5 when the polyacrylic acid are partially charged. In a diluted regime, two diffusive relaxation modes are seen when adding (upon addition) the polyacrylic acid PAA to the microemulsion nanodroplets due to collective diffusion and self-diffusion fluctuations. In the concentrated regime, we observed three diffusive relaxation modes when charged microemulsion nanodroplets complexed with oppositely charged polyacrylic acid. We attribute the two first relaxation modes to the collective diffusion (fluctuation of concentration) and self-diffusion of the microemulsion nanodroplets. The third mode which is a slower relaxation mode; we attribute this relaxation process to the motion of the network formed by the polyacid PAA and microemulsion nanodroplets, or “breathing mode” of the network. [ABSTRACT FROM AUTHOR]

Nanoparticles having a radius of ca. 200 nm are prepared from the proteolytic enzyme trypsin (TRY) and the anionic polysaccharide chondroitin sulfate (CS) by electrostatic complexation at pH 4.3 and subsequent thermal treatment. 3D dynamic light scattering and synchrotron small-angle X-ray scattering are used to assess their size distribution and their inner structure in the pH range up to 11.3. They feature a monomodal size distribution up to pH 8, whereas the distribution becomes very broad above. Their inner structure depends strongly on pH, again with a significant change at pH 9. SAXS reveals hierarchical organization within the NPs. At pH 4.3–8.0, compact TRY-CS complexes at intermediate length scales (∼30 nm), whose size increases by thermal treatment, are present within the NPs. At pH 10.1–11.3 the spherical NPs transform into fractal aggregates. The spherical internal substructure vanishes, and only smaller substructures stay present. At low pH values, where TRY is homogeneously positively charged, these results are attributed to the electrostatic interactions of TRY with CS. At intermediate pH values, where the electrostatic surface potential of TRY is patchy, the TRY-TRY interactions seem to play an important role. The morphological properties of the TRY-CS NPs and their length-scale-dependent response to thermal treatment (20 min at 60 °C) and increase of pH are expected to be crucial for the drug/nutrient loading and release properties and the interactions with other biopolymers, proteins, cells, and tissues. They can also be a useful guide for other polysaccharide–protein biocompatible nanocarriers. [ABSTRACT FROM AUTHOR]

In this study, catalytic-degradation of dyes such as methylene blue (MB) and malachite green (MG) was carried out by using silver nanoparticles (AgNPs), obtained by adopting the flower extract of Luffa acutangula (LA). The biogenic synthesised LA-AgNPs were characterised by using UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), DLS (dynamic light scattering) with zeta potential analysis, X-ray diffraction (XRD) and high-resolution transmission electron microscopic(HR-TEM) analyses. The typical surface plasmon resonance peak of LA-AgNPs was observed at 428 nm, as confirmed from UV-Vis spectrum. The formation of LA-AgNPs was observed through colour transformation from pale yellow to dark-brown due to the reduction of Ag+. Synthesised LA-AgNPs displayed spherical shape and face-centred cubic structure with an average size of 10–30 nm. The effects of various parameters such as initial extract concentration, time and time process were studied. The degradation reactions of MB and MG are found to follow the Langmuir–Hinshelwood mechanism with a pseudo-first-order kinetic model. Biogenic synthesised LA-AgNPs showed good degradation ability to reduce the MG and MB with NaBH4. [ABSTRACT FROM AUTHOR]

Dynamic light scattering has been employed to investigate aqueous Pluronic P123 solutions at different temperatures and in the presence of different solvents and quercetin additives. Significant changes have been revealed in the average particle size and polydispersity index depending on the conditions. The effect of temperature on micellization of the block copolymer in aqueous solutions has been studied in a range T = 15–45°C, which is most often considered when using P123 in the sol–gel synthesis of silica. The most pronounced effect of temperature on the micellization of the studied surfactant has been observed at T = 15–20°C. In this temperature range, the scattered light intensity distribution over particle sizes has a polymodal character, which indicates the presence of macromolecules, micelles, and their aggregates in the system. A further increase in temperature up to 45°C causes no significant changes in the particle size. In aqueous solutions, micelles with a narrow size distribution (minimum polydispersity index) are formed within temperature ranges of 21–25 and 35–40°C. Substantial effects have been found when adding alkanols and polyphenolic substances as solubilizers capable of influencing the structure of micelles both in their bulk and on the surface of polar moieties of the surfactant. It has been shown that, in the presence of butanol-1, micelles are stabilized at temperatures of 15–20°C. At T > 30°C, the structure of micelles is transformed. As the fraction of butanol-1 in the solution increases, its influence is manifested at lower temperatures. It has been noted that ethanol has a destructive effect on micelles. Additives of quercetin exhibit an opposite effect of micelle stabilization, which leads to the formation of a homogeneous surfactant structure. It has been shown that, by varying solvent composition, the flavonoid–micelle binding can be controlled due to changes in the solvation. The greatest influence of quercetin on the structure formation of P123 has been observed at a solvent composition corresponding to ethanol-to-block copolymer molar ratio of n(EtOH) : n(P123) = 80 : 1. [ABSTRACT FROM AUTHOR]

The potential of using centrifugation in the separation of suspended forms from dissolved and colloidal forms in the chemical analysis of river waters is demonstrated in the case of rivers in the south of the Russian Far East. The concentrations of colloidal and suspended particles in nonfiltered water, as well as in centrifugates and filtrates, were characterized with the use of the method of dynamic light scattering (DLS). The comparison of DLS intensity in centrifugates and 0.45-µm filtrates was used to calculate the native density of pelitic and coarse colloidal particles of river suspension, which made it possible to correlate the centrifugation regimes with the size of settling particles within the range from 0.45 to 3 µm. Chemical analysis of supernatants of river water, obtained at different centrifugation regimes was used to evaluate the distribution of chemical elements between dissolved/colloidal (<0.45 µm), coarse-colloidal (0.45–1 µm), and pelite (1–3 µm) fractions. A significant linear relationship was found between the DLS intensity and the concentrations in centrifugates of Fe, Al, Ti, Th, Sc, REE, i.e., chemical elements with a high fraction of coarse colloidal and suspended forms, which confirms the possibility to assess the concentration of colloidal particles in centrifugates by the intensity of DLS. A disadvantage of centrifugation is that it is difficult to use in the field. [ABSTRACT FROM AUTHOR]

Deamidation frequently is invoked as an important driver of crystallin aggregation and cataract formation. Here, we characterized the structural and biophysical consequences of cumulative Asn to Asp changes in γD‐crystallin. Using NMR spectroscopy, we demonstrate that N‐ or C‐terminal domain‐confined or fully Asn to Asp changed γD‐crystallin exhibits essentially the same 1H‐15N HSQC spectrum as the wild‐type protein, implying that the overall structure is retained. Only a very small thermodynamic destabilization for the overall Asn to Asp γD‐crystallin variants was noted by chaotropic unfolding, and assessment of the colloidal stability, by measuring diffusion interaction parameters, yielded no substantive differences in association propensities. Furthermore, using molecular dynamics simulations, no significant changes in dynamics for proteins with Asn to Asp or iso‐Asp changes were detected. Our combined results demonstrate that substitution of all Asn by Asp residues, reflecting an extreme case of deamidation, did not affect the structure and biophysical properties of γD‐crystallin. This suggests that these changes alone cannot be the major determinant in driving cataract formation. [ABSTRACT FROM AUTHOR]

The influence of micellar systems based on cationic surfactants—gadolinium(III) and copper(II) complexes with alkylated 1,4-diazabicyclo[2.2.2]octane, 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide (ligand) and the conventional surfactant cetyltrimethylammonium bromide – on the solubility of the antimalarial drug artemisinin in water was studied by spectrophotometric method. A quantitative assessment of the solubilizing ability of surfactant aggregates was carried out. The value of the solubilization capacity of the systems was determined. The ligand has the greatest influence on the solubility of artemisinin, and, consequently, its bioavailability. The concentration of the drug increases up to 36 times in the presence of a relatively low surfactant content in the aqueous solution. The period of chemical stability of artemisinin in cationic surfactants solutions was determined. Aggregates formed in surfactant-artemisinin systems were characterized by dynamic and electrophoretic light scattering. [ABSTRACT FROM AUTHOR]

Here, we report a novel kind of protein nanoparticles of 11 nm in size, which have a central protein core surrounded by two layers of lipid. One layer of the lipid was covalently attached to the protein, while the other layer has been physically assembled around the protein core. Particle synthesis is highly modular, while both the size and charge of the protein nanoparticles are controlled in a predictable manner. Circular dichroism studies of the conjugate showed that the protein secondary structure is retained, while biophysical characterizations indicated the particle purity, size, and charge. The conjugate had a high thermal stability to steam sterilization conditions at 121°C (17 psi). After labeling the protein core with few different fluorescent dyes, they were strongly fluorescent with the corresponding colors independent of their size, unlike quantum dots. They are readily digested by proteases, and these water‐soluble, non‐toxic, highly stable, biocompatible, and biodegradable conjugates are suitable for cell imaging and drug delivery applications. [ABSTRACT FROM AUTHOR]

A novel construction strategy is introduced for an ultrasensitive dynamic light scattering (DLS) immunosensor targeting alpha fetoprotein (AFP). This approach relies on a self-assembled heptamer fusion protein (A1-C4bpα), incorporating the dual functions of multivalent recognition and crosslinking aggregation amplification due to the presence of seven AFP-specific A1 nanobodies on the A1-C4bpα heptamer. Leveraging antibody-functionalized magnetic nanoparticles for target AFP capture and DLS signal output, the proposed heptamer-assisted DLS immunosensor offers high sensitivity, strong specificity, and ease of operation. Under the optimized conditions, the designed DLS immunosensor demonstrates excellent linear detection of AFP in the concentration range 0.06 ng mL−1 to 512 ng mL−1, with a detection limit of 15 pg mL−1. The selectivity, accuracy, precision, practicability, and reliability of this newly developed method were further validated through an assay of AFP levels in spiked and actual human serum samples. This work introduces a novel approach for constructing ultrasensitive DLS immunosensors, easily extendable to the sensitive determination of other targets via simply replacing the nanobody sequence, holding great promise in various applications, particularly in disease diagnosis. [ABSTRACT FROM AUTHOR]

Nanoparticles are emerging as a fascinating alternative to antibiotics. When stabilized by chemical compounds, magnetite nanoparticles (MagNPs) consistently exhibit bactericidal effects across different types of bacteria. This study describes the synthesis, characterization, and antibacterial properties of magnetite MagNPs prepared by the coprecipitation method under continuous sonication. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Dynamic Light Scattering (DLS) techniques revealed Fe3O4-NPs as spherical, uniform particles with an average size of approximately 16 nm. The antibacterial efficacy of MagNPs was investigated by combining them with methanolic extracts of three medicinal plants known for their antibacterial properties: Aloysia triphylla, Sarcopoterium spinosum, and Urtica pilulifera. The combined effect was assessed against both wild type and resistant strains of Staphylococcus aureus and Escherichia coli. The antibacterial synergistic effect of MagNPs and plant extracts was evaluated by the MIC test, which showed significant inhibitory properties against the growth of the four bacterial strains as compared to control samples of plant extracts alone. Furthermore, the synergistic effect of MagNPs combined with extracts from Rosmarinus officinalis, Anchusa azurea, Quercus infectoria, and Urtica pilulifera significantly prevented biofilm development in both sensitive and resistant strains of Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

In this paper, we present an efficient and rapid method for synthesizing perovskite nanoparticles (PeNPs) using ultrasonic spray techniques. The synthesized PeNPs are notably larger than the exciton Bohr radius of perovskite, avoiding the quantum confinement effect, and exhibit a size distribution of around 61.6 ± 30 nm. They show an exceptionally narrow full width at half-maximum of approximately 21.8 nm and a high exciton binding energy (Eb) of approximately 204 meV. Furthermore, the physically restrained reprecipitation method not only effectively transforms perovskite precursor droplets into solid PeNPs at the interface of an antisolvent but also concurrently achieves ligand passivation. This dual-action mechanism promotes their dispersion in various organic solvents and highly concentrated solutions, thus significantly expanding the scope of potential optoelectronic applications such as light-emitting diodes and photodetectors. [ABSTRACT FROM AUTHOR]

Plastic materials are used in various domains, such as constructions, textile, or medical applications, due to their durability and versatility. Despite plastics contribution to human wellbeing, these materials can also have a negative impact on ecosystems, leading to water pollution and loss of aquatic life. However, no study has been made, so far, to determine the impact of plastic products on natural particle size distribution in water systems. The aim of this study is to evaluate if plastic affects aquatic particulate matter of different size ranges, from 0.3 to 16 000 nm. Three types of plastics (polystyrene [PS], polypropylene [PP], and low‐density polyethylene [LDPE]) have been added to lake water samples and incubated for nine months at room temperature. Results show that the average particle size increases toward the end of the experiment indicating that small particles (<1200 nm) adhere to plastic surfaces, while medium and large particles sediment in the water sample. Also, substances migrating from plastic may alter the aggregating properties of particles. However, the influence may be less substantial in the environment, as plastic types and concentrations differ. Moreover, more studies are needed to establish additional implications in relation to bacterial communities, transport of pollutants, or chemical composition. [ABSTRACT FROM AUTHOR]

A lot of literature sources discuss diseases associated with the hemoglobin protein [1-2]. In the modern world, more than 800 million people suffer from anemia [3]. Assessing the level of hemoglobin in the circulatory system is one of the ways to diagnose anemia. Hemoglobin protein is also a promising source of bioactive peptides [4]. The aim of the work was to identify the reasons leading to conformation changes of this protein. It still remains unclear what exactly causes disruption of its functionality. Human hemoglobin from Sigma H7379 was studied in the work; all experiments were conducted on a dynamic light scattering spectrometer—Photocor Complex. Experimental data were obtained using optical methods of static and dynamic light scattering. The work included an analysis of the behaviour of hemoglobin protein molecules in aqueous and aqueous-saline solutions with changes in solution parameters (pH, addition of iron chloride III). At values of pH and pH , the hemoglobin molecule underwent conformational changes, resulting in the disintegration of the quaternary structure into -dimers and individual - and -globules. As a result of the study, it was found that the addition of FeCl to aqueous solutions of hemoglobin increases the size and mass of scattering particles, which can be explained by the adsorption of Fe ions on the protein surface. However, upon reaching a certain concentration of FeCl , the pH of the solution was lowered to such an extent that it caused conformational changes in hemoglobin, leading to the disintegration of its quaternary structure. These results can be taken into account when creating medicinal drugs for the treatment of anemia and other diseases associated with the hemoglobin protein. [ABSTRACT FROM AUTHOR]

Rieske oxygenases (ROs) are a diverse metalloenzyme class with growing potential in bioconversion and synthetic applications. We postulated that ROs are nonetheless underutilized because they are unstable. Terephthalate dioxygenase (TPADO PDB ID 7Q05) is a structurally characterized heterohexameric α3β3 RO that, with its cognate reductase (TPARED), catalyzes the first intracellular step of bacterial polyethylene terephthalate plastic bioconversion. Here, we showed that the heterologously expressed TPADO/TPARED system exhibits only ~300 total turnovers at its optimal pH and temperature. We investigated the thermal stability of the system and the unfolding pathway of TPADO through a combination of biochemical and biophysical approaches. The system's activity is thermally limited by a melting temperature (Tm) of 39.9°C for the monomeric TPARED, while the independent Tm of TPADO is 50.8°C. Differential scanning calorimetry revealed a two‐step thermal decomposition pathway for TPADO with Tm values of 47.6 and 58.0°C (ΔH = 210 and 509 kcal mol−1, respectively) for each step. Temperature‐dependent small‐angle x‐ray scattering and dynamic light scattering both detected heat‐induced dissociation of TPADO subunits at 53.8°C, followed by higher‐temperature loss of tertiary structure that coincided with protein aggregation. The computed enthalpies of dissociation for the monomer interfaces were most congruent with a decomposition pathway initiated by β‐β interface dissociation, a pattern predicted to be widespread in ROs. As a strategy for enhancing TPADO stability, we propose prioritizing the re‐engineering of the β subunit interfaces, with subsequent targeted improvements of the subunits. [ABSTRACT FROM AUTHOR]

Taghrid S Alomar,1 Najla AlMasoud,1 Manal A Awad,2 Reem S AlOmar,3 Nada M Merghani,4 Mohamed El-Zaidy,5 Ajaya Bhattarai6 1Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, 11671, Saudi Arabia; 2King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia; 3Department of Family and Community Medicine, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, 32210, Saudi Arabia; 4Central Research Laboratory, Vice Rectorate for Studies and Scientific Research, King Saud University, Riyadh, 11451, Saudi Arabia; 5Department of Botany and Microbiology, Faculty of Science, King Saud University, Riyadh, 11459, Saudi Arabia; 6Department of Chemistry, Mahendra Morang Adarsh Multiple Campus, Tribhuvan University, Biratnagar, 56613, NepalCorrespondence: Ajaya Bhattarai; Manal A Awad, Email ajaya.bhattarai@mmamc.tu.edu.np; mawad@ksu.edu.saIntroduction: Researchers are increasingly favouring the use of biological resources in the synthesis of metallic nanoparticles. This synthesis process is quick and affordable. The current study examined the antibacterial and anticancer effects of silver nanoparticles (AgNPs) derived from the Neurada procumbens plant. Biomolecules derived from natural sources can be used to coat AgNPs to make them biocompatible.Methods: UV-Vis spectroscopy was used to verify the synthesis of AgNPs from Neurada procumbens plant extract, while transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR) were used to characterize their morphology, crystalline structure, stability, and coating.Results: UV-visible spectrum of AgNPs shows an absorption peak at 422 nm, indicating the isotropic nature of these nanoparticles. As a result of the emergence of a transmission peak at 804.53 and 615.95 cm− 1 in the spectrum of the infrared light emitted by atoms in a sample, FTIR spectroscopy demonstrated that the Ag stretching vibration mode is metal-oxygen (M-O). Electron dispersive X-ray (EDX) spectral analysis shows that elementary silver has a peak at 3 keV. Irradiating the silver surface with electrons, photons, or laser beams triggers the illumination. The emission peak locations have been found between 300 and 550 nm. As a result of DLS analysis, suspended particles showed a bimodal size distribution, with their Z-average particle size being 93.38 nm.Conclusion: The findings showed that the antibacterial action of AgNPs was substantially (p≤ 0.05) more evident against Gramme-positive strains (S. aureus and B. cereus) than E. coli. The biosynthesis of AgNPs is an environmentally friendly method for making nanostructures that have antimicrobial and anticancer properties.Keywords: Silver nanoparticles, UV-Vis spectroscopy, transmission peak, dynamic light scattering

This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution, conducted with dynamic light scattering technique. The objects of the study were four samples of asphaltenes obtained from four different oils. For all samples, the change in the average size of the asphaltene submicron aggregates with time was measured after the addition of a precipitant (heptane) to a solution of asphaltenes in toluene at an amount above the threshold concentration. Asphaltene aggregates formed in solution after the addition of the precipitant and were subjected to ultrasonic treatment, which led to the destruction of the asphaltene aggregates. Aggregation of destroyed asphaltenes was observed. The kinetics of this aggregation were similar to the kinetics of aggregation of asphaltenes after the addition of a precipitant. Multiple iterations of asphaltene aggregate destruction in the sample led to a significant change in the kinetics of aggregation: the growth of aggregates slowed and stabilized at a size of approximately 200 nm and 30 nm for the different studied samples.

Knowledge of diffusion in water or aqueous solutions of sodium chloride with dissolved hydrogen and methane is important for geological hydrogen storage. This study examines the accessibility of diffusivities in the corresponding mixtures through dynamic light scattering at macroscopic thermodynamic equilibrium and provides corresponding data for hydrogen-storage-relevant temperatures T up to 393 K and pressures up to 20 MPa. The thermal and mutual diffusivities are simultaneously accessible in mixtures of water and hydrogen. Moreover, for water with dissolved mixtures of hydrogen and methane, the thermal diffusivity and an apparent diffusivity related to the diffusion of the gas mixture can be accessed. In aqueous solutions of sodium chloride at T > 300 K, a strong molecular association leading to a quasi-static light-scattering pattern in the liquid sample was observed, which hindered the determination of the molecular gas diffusivities. However, the salt diffusion coefficient was accessible for all T values. [Display omitted] •First-time application of dynamic light scattering to H 2 O/brine-H 2 /CH 4 systems. • Experimental diffusivity data up to 393 K and 20 MPa. • Presence of sodium chloride does not influence gas diffusion significantly. • Correlation for estimating the mass diffusivity of dissolved H 2 /CH 4 in H 2 O/brine. [ABSTRACT FROM AUTHOR]

[Display omitted] Surfactants are inexpensive chemicals with promising applications in virus inactivation, particularly for enveloped viruses. Yet, the detailed mechanisms by which surfactants deactivate coronaviruses remain underexplored. This study delves into the virucidal mechanisms of various surfactants on Feline Coronavirus (FCoV) and their potential applications against more pathogenic coronaviruses. By integrating virucidal activity assays with fluorescence spectroscopy, dynamic light scattering and laser Doppler electrophoresis, alongside liposome permeability experiments, we have analyzed the effects of non-ionic and ionic surfactants on viral activity. The non-ionic surfactant octaethylene glycol monodecyl ether (C 10 EO 8) inactivates the virus by disrupting the lipid envelope, whereas ionic surfactants like Sodium Dodecyl Sulfate and Cetylpyridinium Chloride predominantly affect the spike proteins, with their impact on the viral membrane being hampered by kinetic and thermodynamic constraints. FCoV served as a safe model for studying virucidal activity, offering a faster alternative to traditional virucidal assays. The study demonstrates that physicochemical techniques can expedite the screening of virucidal compounds, contributing to the design of effective disinfectant formulations. Our results not only highlight the critical role of surfactant-virus interactions but also contribute to strategic advancements in public health measures for future pandemic containment and the ongoing challenge of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Pretransitional behaviour, with strong softening of the bend or splay elastic constants, is characteristic of two of the nematic to nematic phase transitions reported in the last decade. Such softening is strongly reflected in the pretransitional behaviour of the thermally excited director fluctuations. Here we give a comprehensive overview of the cross-Differential Dynamic Microscopy (c-DDM) method and its application to the investigation of thermal director fluctuations and phase transitions. For this, we build on the potentialities of the method for the investigation of the standard nematic phase of E7 to compare with the pretransitional behaviour of the nematic to twist bend nematic phase transition as well as the nematic to ferroelectric nematic transition. [ABSTRACT FROM AUTHOR]

A dynamic light-scattering method for qualitative analysis was developed and used in production and quality control of hydrolyzed collagen (HC). A semiquantitative analytical method based on ultrafiltration coupled with spectrophotometry was proposed for the peptide fraction with molecular mass <10 kDa, which determines the most significant properties of HC. [ABSTRACT FROM AUTHOR]

Biological nanoparticles (NPs), such as extracellular vesicles (EVs), exosome-mimetic nanovesicles (EMNVs) and nanoghosts (NGs), are perspective non-viral delivery vehicles for all types of therapeutic cargo. Biological NPs are renowned for their exceptional biocompatibility and safety, alongside their ease of functionalization, but a significant challenge arises when attempting to load therapeutic payloads, such as nucleic acids (NAs). One effective strategy involves fusing biological NPs with liposomes loaded with NAs, resulting in hybrid carriers that offer the benefits of both biological NPs and the capacity for high cargo loads. Despite their unique parameters, one of the major issues of virtually any nanoformulation is the ability to escape degradation in the compartment of endosomes and lysosomes which determines the overall efficiency of nanotherapeutics. In this study, we fabricated all major types of biological and hybrid NPs and studied their response to the acidic environment observed in the endolysosomal compartment. In this study, we show that EMNVs display increased protonation and swelling relative to EVs and NGs in an acidic environment. Furthermore, the hybrid NPs exhibit an even greater response compared to EMNVs. Short-term incubation of EMNVs in acidic pH corresponding to late endosomes and lysosomes again induces protonation and swelling, whereas hybrid NPs are ruptured, resulting in the decline in their quantities. Our findings demonstrate that in an acidic environment, there is enhanced rupture and release of vesicular cargo observed in hybrid EMNVs that are fused with liposomes compared to EMNVs alone. This was confirmed through PAGE electrophoresis analysis of mCherry protein loaded into nanoparticles. In vitro analysis of NPs colocalization with lysosomes in HepG2 cells demonstrated that EMNVs mostly avoid the endolysosomal compartment, whereas hybrid NPs escape it over time. To conclude, (1) hybrid biological NPs fused with liposomes appear more efficient in the endolysosomal escape via the mechanism of proton sponge-associated scavenging of protons by NPs, influx of counterions and water, and rupture of endo/lysosomes, but (2) EMNVs are much more efficient than hybrid NPs in actually avoiding the endolysosomal compartment in human cells. These results reveal biochemical differences across four major types of biological and hybrid NPs and indicate that EMNVs are more efficient in escaping or avoiding the endolysosomal compartment. [ABSTRACT FROM AUTHOR]

Polysaccharide-based systems have very good emulsifying and stabilizing properties, and starch plays a leading role. Their modifications should add new quality features to the product to such an extent that preserves the structure-forming properties of native starch. The aim of this manuscript was to examine the physicochemical characteristics of the combinations of starch with phospholipids or lysozymes and determine the effect of starch modification (surface hydrophobization or biological additives) and preparation temperature (before and after gelatinization). Changes in electrokinetic potential (zeta), effective diameter, and size distribution as a function of time were analyzed using the dynamic light scattering and microelectrophoresis techniques. The wettability of starch-coated glass plates before and after modification was checked by the advancing and receding contact angle measurements, as well as the angle hysteresis, using the settle drop method as a complement to profilometry and FTIR. It can be generalized that starch dispersions are more stable than analogous n-alkane/starch emulsions at room and physiological temperatures. On the other hand, the contact angle hysteresis values usually decrease with temperature increase, pointing to a more homogeneous surface, and the hydrophobization effect decreases vs. the thickness of the substrate. Surface hydrophobization of starch carried out using an n-alkane film does not change its bulk properties and leads to improvement of its mechanical and functional properties. The obtained specific starch-based hybrid systems, characterized in detail by switchable wettability, give the possibility to determine the energetic state of the starch surface and understand the strength and specificity of interactions with substances of different polarities in biological processes and their applicability for multidirectional use. [ABSTRACT FROM AUTHOR]

In this study, a series of four surface-active compounds—N-alkyl betaine ethyl ester chlorides, CnBetC2Cl—were synthesized and characterized in aqueous solutions. As with other alkyl betaines, these amphiphiles can be practically used, for example, as co-surfactants and/or solubility enhancers acting according to hydrotropic or micellar mechanisms, depending on the alkyl chain length in the amine. We focused on the representatives of the medium alkyl chain length (C6–C12) to find the dependence between the alkyl chain length in N-alkyl betaine ethyl ester chlorides and the surface, volumetric, acoustic, and viscometric properties of their solutions. Ethyl esters, the derivatives of amino acids, were chosen to increase functionality and take advantage of possible hydrolysis in solutions at higher pH, which is also a key parameter in biodegradability. The micellization parameters were calculated based on the physicochemical characteristics. We focused our interest on the ester with a dodecyl substituent since we can compare and discuss its properties with some other C12 representatives that are available in literature. Surprisingly, its micellization characteristic is almost temperature-independent in the investigated temperature range, t = (15–45) °C. Particularly interesting are the results of dynamic light scattering (DLS), which show that the changes in physicochemical parameters of the C12 homolog around the CMC are caused by the two types of micelles of different sizes present in solutions. [ABSTRACT FROM AUTHOR]

Nanoparticles have emerged as versatile drug delivery vehicles suitable for a wide range of administration routes. Over time, researchers have explored numerous natural and synthetic polymers for nanoparticle preparation, with particular focus on Poly(lactic acid) (PLA), Poly(glycolic acid) (PGA), and their copolymers (PLGA) due to their favorable biocompatibility and biodegradability. These nanoparticles serve as carriers for various drug classes, including anticancer agents, antihypertensive drugs, immunomodulators, and hormones, as well as macromolecules like nucleic acids, proteins, peptides, and antibodies. This study investigates the impact of surfactant concentration on the size of poly(lacticco-glycolic acid) (PLGA) nanoparticles. Through a systematic exploration of different surfactant concentrations, ranging from low to high levels, the size distribution of PLGA nanoparticles is analyzed using dynamic light scattering (DLS) or similar techniques. The abstract summarizes the observed relationship between surfactant concentration and nanoparticle size, providing insights into the optimal conditions for controlling PLGA nanoparticle size in various applications, from drug delivery to biomedical engineering. [ABSTRACT FROM AUTHOR]

Nanodiamonds (NDs) are promising carriers of radionuclides in radiopharmaceuticals for the use in nuclear medicine. In this work, we investigated the influence of the properties of NDs suspensions, including the sizes of their aggregates, in aqueous solutions with different pH on their binding of medical isotopes 90Y and 177Lu and determination of conditions for fabricating promising conjugates for further in vivo studies. It was shown that sorption is influenced by the composition of the solution, which determines the properties of the NDs surface, while the forms of cations of the studied nuclides in the solution do not affect the sorption value. [ABSTRACT FROM AUTHOR]

The present article summarizes experimental and theoretical considerations required for a proper use of dynamic light scattering (DLS) for the measurement of transport properties of fluids. It addresses not only recent advancements of the method, but also aims to provide recommendations to researchers who intend to apply the technique in the future. As outlined in this study, DLS is based on the analysis of scattered light governed by microscopic statistical or periodic fluctuations that originate from the thermal movement of molecules and/or particles at macroscopic thermodynamic equilibrium. The dynamics of these hydrodynamic fluctuations in the bulk of fluids or at their phase boundaries are related to the underlying diffusive processes and, thus, to the associated transport properties, and are reflected by the time-dependent correlation function of the scattered light intensity. The fundamentals of this type of detection, known as photon correlation spectroscopy (PCS), will be discussed in the present contribution in some more detail. It is emphasized that the experiments need to be designed carefully in accordance with theory in order to assign the measurement signals to the corresponding hydrodynamic fluctuations. If the necessary conditions are fulfilled, DLS allows the accurate determination of several transport properties including kinematic and dynamic viscosity, thermal diffusivity, mutual diffusivity, and sound attenuation, which may be accessed together with other thermophysical properties such as speed of sound and surface or interfacial tension. In some instances, also the simultaneous determination of several transport properties is possible. With the exception of the sound attenuation, expanded uncertainties for the mentioned transport properties down to 1 % can be achieved for various types of fluid systems over a wide range of thermodynamic states up to elevated temperatures and pressures as well as in the vicinity of critical points. This performance and versatility of the DLS technique is documented in the present study by highlighting measurement examples from recent thermophysical property research on different classes of working fluids relevant for process and energy technology. [ABSTRACT FROM AUTHOR]

Monoclonal antibodies represent the rapidly expanding class of biotherapeutics having applications in the treatment of cancer, autoimmune disorders, metabolic disorders, and infectious diseases. One of the major challenges in mAb-based therapeutics development lies in the significant issue of aggregation which in turn has an impact on the quality, safety, and efficacy of the antibody drug. The presence of aggregates in the drug substance or final drug product potentially affects its biological activity thereby making it a critical quality attribute to be assessed. State-of-the-art analytical techniques are required for quality control and detailed characterization. This review provides insight into monoclonal antibody aggregation and the analytical techniques used to detect and quantify these aggregates. [ABSTRACT FROM AUTHOR]

Polymer nanocomposite materials with catalytic activity were designed via modification of MF-4SK ion-exchange membranes with Au and Ag nanoparticles obtained according to various synthetic methods in reverse micellar solutions. A sufficient transparency of the films allowed us to detect nanoparticles in the films using UV–Vis spectrophotometry, monitoring changes in the content of metal nanoparticles in the reverse micellar solution. A different mechanism of interaction of Au and Ag nanoparticles obtained by the same synthetic method with the MF-4SK film upon their contact with its surface was discovered, the destruction of nanoparticles was observed, and the influence of mechanism of primary acts in the formation of metal nanoparticles in reverse micellar solutions on their adsorption properties was confirmed. The highest concentration of gold nanoparticles was found in films immersed in reverse micellar solutions at the time of their exposure to ionizing radiation. [ABSTRACT FROM AUTHOR]

The possibility of synthesizing nanoparticles by pulsed laser ablation of thin cobalt films in water is shown. The average size of the formed nanoparticles varies in the range of 70–1020 nm depending on the thickness of the ablated film. At film thicknesses less than 35 nm, the size dispersion of the nanoparticles is minimum. The produced nanoparticles are characterized by magnetic response and structurally most closely correspond to cobalt oxide Co3O4. [ABSTRACT FROM AUTHOR]

Dynamic light scattering (DLS) measurements have been performed on the polyacrylic acid (PAA) to investigate the polyelectrolyte effect on its solution dynamics. Viscosity measurements confirm the solution to be in the nondilute regime. The polyelectrolyte impacts are contrasted by using two solution pHs, five electrolyte concentrations, and in each with four different polymer concentrations. An interesting ergodic → nonergodic → ergodic transitions are being observed with variation in solution pH and electrolyte concentrations, which is directly coupled to a similar transition between bi‐modal and triple mode relaxation. The partial heterodyne method is used to analyze the DLS data exhibiting nonergodicity; otherwise, the standard Siegert relation is being employed. For the new third mode of relaxation, in addition to the conventional fast and slow mode, a novel term of nonergodic mode being coined because of a direct association between its presence with the sample becoming nonergodic. The fast relaxation time being analyzed through Rouse model and both the nonergodic and slow relaxation time show a monotonous increase with rise in polymer concentration. The stretched exponent β, a measure of inhomogeneity, decreases with increase in solution pH and polymer concentration while increases with the addition of salt to the solution. [ABSTRACT FROM AUTHOR]

The function of immune complexes in rheumatoid arthritis (RA) is related to their composition and size. Using dynamic light scattering (DLS), we investigated the link between the RA circulating immune complex (CIC) particles' size and the CIC immunoglobulin level. In this study, 30 RA patients and 30 healthy individuals were included. IgA, IgG, and IgM were found in all analyzed CICs, but more IgA and IgG were found in RA than in control CICs. In both control and RA CICs, DLS detected 50 particles that differed in size and clustered around two size groups: with a 7.5–164 nm radius and with a 342–1718 nm radius. An increased level of IgA in RA CICs, compared to control ones, was associated with more than 50% of CIC particles. In RA, compared to the control, a higher number of CICs with 28.2 nm, 531 nm, 712 nm, and 1718 nm particles and a lower number of CICs with 78.8 nm particles were detected. This particle distribution pattern did not reflect the changes in the CIC immunoglobulin level. Thus, RA elevated CIC IgA was linked with all these particles (except the 1718 nm particle), the IgM increase was linked with 43.8 nm and 712 nm particles, and the IgG increase was linked with the 712 nm particle only. This study provides the very first data on the association between CIC particles' size, CIC immunoglobulin level, and RA. It opens the possibility that the size of CICs determined by DLS can be used as a criterion in RA diagnosis or monitoring after a large-scale study confirmation. [ABSTRACT FROM AUTHOR]