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The collective dynamics of 25 wt% poly(N-isopropylacrylamide) (PNIPAM) solutions in water or an 80:20 v/v water/methanol mixture are investigated in the one-phase region in dependence on pressure and temperature using dynamic light scattering. Throughout, two dynamic modes are observed, the fast one corresponding to the relaxation of the chain segments within the polymer blobs and the slow one to the relaxation of the blobs. A pressure scan in the one-phase region on an aqueous solution at 34.0 °C, i.e., slightly below the maximum of the coexistence line, reveals that the dynamic correlation length of the fast mode increases when the left and the right branch of the coexistence line are approached. Thus, the chains are rather swollen far away from the coexistence line, but contracted near the phase transition. Temperature scans of solutions in neat H2O or in H2O/CD3OD at 0.1, 130, and 200 MPa reveal that the dynamic correlation length of the fast mode shows critical behavior. However, the critical exponents are significantly larger than the value predicted by mean-field theory for the static correlation length, ν = 0.5, and the exponent is significantly larger for the solution in the H2O/CD3OD mixture than in neat H2O. [ABSTRACT FROM AUTHOR]

The dynamic light scattering technique is used to probe the relaxation modes of a smart system composed of weakly charged microemulsion and a polyelectrolyte. The complex is formed by oil in water microemulsion comprising Triton X-100 (TX100) as surfactant, cosurfactant (octanol), oil (decane) and Polyacrylic acid (PAA) which is a pH dependent polyelectrolyte. All the dynamic studies of the solutions were carried out in a basic medium at pH = 12. In the bare microemulsion (without PAA added), the analysis of the autocorrelation functions exhibits one relaxation mode, reflecting the Brownian motion of the particles. However, the dynamic light scattering (DLS) autocorrelation function shows the existence of two relaxation modes, fast and slow modes, in charged microemulsion mixed with PAA. The fast relaxation mode is diffusive and is associated to the collective diffusion of the charged particles. The slow mode is also diffusive but the mechanism at the origin is the subject of controversy. It is very likely that it arises from the entanglement of the network formed by the droplets of the microemulsion and the polyelectrolyte. [ABSTRACT FROM AUTHOR]

Particle size inversion of dynamic light scattering (DLS) is a typically ill-posed problem. Regularization is an effective method to solve the problem. The regularization involves imposing constraints on the fitted autocorrelation function data by adding a norm. The classical regularization inversion for DLS data is constrained by the L2 norm. In the optimization equation, the norm determines the smoothness and stability of the inversion result, affecting the inversion accuracy. In this paper, the Lp norm regularization model is constructed. When p is 1, 2, 10, 50, 100, 1000, and ∞, respectively, the influence of their norm models on the inversion results of data with different noise levels is studied. The results prove that overall, the inversion distribution errors show a downward trend with the increase of p. When p is larger than 10, there is no significant difference in distribution error. Compared with L2, L∞ can provide better performance for unimodal particles with strong noise, although this does not occur in weak noise cases. Meanwhile, L∞ has lower sensitivity to noise and better peak resolution, and its inverse particle size distribution is closer to the true distribution for bimodal particles. Thus, L∞ is more suitable for the inversion of DLS data. [ABSTRACT FROM AUTHOR]

Despite the fact that amphiphilic block copolymers have been studied in detail by various methods both in common solvents and aqueous dispersions, their hydrodynamic description is still incomplete. In this paper, we present a detailed hydrodynamic study of six commercial diblock copolymers featuring the same hydrophilic block (poly(ethylene glycol), PEG; degree of polymerization is ca. 110 ± 25) and the following hydrophobic blocks: polystyrene, PS35-b-PEG115; poly(methyl methacrylate), PMMA55-b-PEG95; poly(1,4-butadyene), PBd90-b-PEG130; polyethylene PE40-b-PEG85; poly(dimethylsiloxane), PDMS15-b-PEG115; and poly(ɛ-caprolactone), PCL45-b-PEG115. The hydrodynamic properties of block copolymers are investigated in both an organic solvent (tetrahydrofuran) and in water micellar dispersions by the combination of static/dynamic light scattering, viscometry, and analytical ultracentrifugation. All the micellar dispersions demonstrate bimodal particle distributions: small compact (hydrodynamic redii, Rh ≤ 17 nm) spherical particles ascribed to "conventional" core–shell polymer micelles and larger particles ascribed to micellar clusters. Hydrodynamic invariants are (2.4 ± 0.4) × 10−10 g cm2 s−2 K−1 mol−1/3 for all types of micelles used in the study. For aqueous micellar dispersions, in view of their potential biomedical applications, their critical micelle concentration values and cytotoxicities are also reported. The investigated micelles are stable towards precipitation, possess low critical micelle concentration values (with the exception of PDMS15-b-PEG115), and demonstrate low toxicity towards Chinese Hamster Ovarian (CHO-K1) cells. [ABSTRACT FROM AUTHOR]

N,N‐didodecyl‐N',N'‐dioctyl diglycolamide (D3DODGA) was regarded as a promising ligand for the extraction of trivalent lanthanides and actinides from nuclear waste, owing to the absence of undesirable third phase formation during liquid‐liquid extraction. However, the reason for the absence of third phase formation in D3DODGA as compared to other diglycolamides was not known. To unravel the absence of third phase formation, the extraction behaviour of nitric acid and Nd(III) in 0.2 M D3DODGA in n‐dodecane (n‐DD) was studied and the reverse micellar aggregation behaviour of the organic phase was probed by dynamic light scattering (DLS) and FTIR spectroscopy. The results were compared with those obtained in popular ligands abbreviated as TODGA, TEHDGA and TDdDGA in n‐dodecane under similar conditions. The limiting reverse micellar aggregate size for third phase formation was determined to be 11.6 nm at the limiting nitric acid concentration of 0.54 M in organic phase. The investigations revealed that the absence of third phase in D3DODGA and TDdDGA was due to the presence of long chain dodecyl group attached to the molecule, as compared to the octyl moiety present in TODGA and TEHDGA. As a result, it was possible to load higher concentration of nitric acid or Nd(III) in D3DODGA without the problem of third phase formation. In view of this, the D3DODGA in n‐DD can be employed efficiently for the separation of trivalent actinides and lanthanides from nuclear waste. [ABSTRACT FROM AUTHOR]

This study is a continuation of the work on the use of dynamic light scattering (DLS) for the analysis of active component particle sizes in supported catalysts. It was shown that the proposed STS (from solid to sol) approach is also applicable to supported catalysts based on sparingly soluble supports and nanocomposites. It was found that partial dissolution or destruction of a support with the formation of solution containing the desired nanoparticles is sufficient for effective DLS analysis. It was found that, under certain conditions, the effect of secondary aggregation of nanoparticles in solution can be observed in the course of catalyst dissolution, and this effect can prevent correct measurements. A method was proposed to avoid the secondary aggregation of particles in the course of the selective dissolution of a support. A good agreement between the results obtained by the new (DLS) method and traditional (TEM and XRD) methods was demonstrated. [ABSTRACT FROM AUTHOR]

Biomimetic models are valuable platforms to improve our knowledge on the molecular mechanisms governing membrane-driven processes in (patho)physiological conditions, including membrane permeability, transport, and fusion. However, current membrane models are over simplistic and do not include the membrane's lipid remodelling in response to extracellular stimuli. Our study describes the synthesis of glycated dimyristoyl-phosphatidylethanolamine (DMPE-glyc), which was structurally characterised by mass spectrometry (ESI-MS) and quantified by NMR spectroscopy to be further incorporated in a complex phospholipid (PL) membrane model enriched in cholesterol (Chol) and (glyco)sphingolipids (GSL) designed to mimic epithelial membranes (PL/Chol/GSL) under hyperglycaemia conditions. Characterisation of synthesised DMPE-glyc adducts by tandem mass spectrometry (ESI-MS/MS) show that synthetic DMPE-glyc adducts correspond to Amadori products and quantification by 1H NMR spectroscopy show that the yield of glycation reaction was 8%. The biophysical characterisation of the epithelial membrane model shows that excess glucose alters the thermotropic behaviour and fluidity of epithelial membrane models likely to impact permeability of solutes. The epithelial membrane models developed to mimic normo- and hyperglycaemic scenarios are the basis to investigate (poly)phenol-lipid and drug–membrane interactions crucial in nutrition, pharmaceutics, structural biochemistry, and medicinal chemistry. [ABSTRACT FROM AUTHOR]

We present investigations of the structures and properties of the complex formed by a strong polyanion: poly-(sodium 4-styrene sulfonate) (PSSNa) and weak polycation: poly-L-ornithine (PLO) by combining dynamic light scattering (DLS), ultra-small-angle light scattering (USALS), turbidimetry, and zetametry techniques. The mixtures of polyelectrolytes were controlled in several ways: by the change of pH, modifying the mass ratio, the temperature, and adding divalent salt. Under these conditions, the hydrodynamic radius RH, the viscosity η, the radius of gyration Rg, and the fractal dimension Df were determined. The maximum charge difference of biopolymers stock dispersion was displayed at pH 3.3 and at mass ratio equal to 1. The screen of electrostatic interaction shows a high contribution of hydrophobic interaction at large salt concentration to form the coacervates and the effect of temperature and ionic strength highlighted the strongly hydrophobic character of mixture. The results allowed us to conclude that the complexation was controlled by electrostatic interactions between opposites charges. [ABSTRACT FROM AUTHOR]

Gramicidin (Gr) nanoparticles (NPs) and poly (diallyl dimethyl ammonium) chloride (PDDA) water dispersions were characterized and evaluated against Gram-positive and Gram-negative bacteria and fungus. Dynamic light scattering for sizing, zeta potential analysis, polydispersity, and colloidal stability over time characterized Gr NPs/PDDA dispersions, and plating and colony-forming units counting determined their microbicidal activity. Cell viabilities of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in the presence of the combinations were reduced by 6, 7, and 7 logs, respectively, at 10 μM Gr/10 μg·mL−1 PDDA, 0.5 μM Gr/0. 5μg·mL−1 PDDA, and 0.5 μM Gr/0.5 μg·mL−1 PDDA, respectively. In comparison to individual Gr doses, the combinations reduced doses by half (S. aureus) and a quarter (C. albicans); in comparison to individual PDDA doses, the combinations reduced doses by 6 times (P. aeruginosa) and 10 times (C. albicans). Gr in supported or free cationic lipid bilayers reduced Gr activity against S. aureus due to reduced Gr access to the pathogen. Facile Gr NPs/PDDA disassembly favored access of each agent to the pathogen: PDDA suctioned the pathogen cell wall facilitating Gr insertion in the pathogen cell membrane. Gr NPs/PDDA differential cytotoxicity suggested the possibility of novel systemic uses for the combination. [ABSTRACT FROM AUTHOR]

Hydrophobically modified amino-pullulan polymers (CHPNH2) were modified with polyethylene glycol (PEG) through the connective arms of succinic anhydride (SA) and cis aconite anhydride (CA) to form three polymers, namely, PCCN1, PCCN2 and PSCN, respectively. The structure of the polymer was identified by 1H NMR, and the degree of substitution (DS) values of hydrophobic groups were calculated. Three types of nanoparticles (NPs) were prepared by the dialysis method, and the average particle sizes by dynamic light scattering (DLS) were 166.9 nm, 118.9 nm and 118.7 nm. The drug release experiment showed that the three drug-loaded nanoparticles all had a slow-release effect. The results of the MTT experiment showed that the cell survival rates of free cisplatin and the three types of drug-loaded nanoparticles were 42.30%, 40.17%, 37.53% and 53.34% after 48 h at the maximum drug concentration, indicating that PCCN1 nanoparticles have the strongest cytotoxicity. They also had the highest cell uptake rate in cell uptake experiments. [ABSTRACT FROM AUTHOR]

We analyze the results of the laser granulometry of a nanosized fraction of settled aerosol substance and UV spectrometry of water washouts from the surfaces of different-age needles of four forest-forming plant species. The activity of efflorescence of phenolic compounds onto different–age needle surfaces is estimated for the period of winter dormancy of plants. A possibility is shown for the secondary organic aerosol production as a result of photoactivated reactions between phenolic compounds and deposited aerosol substance. It is discussed how secondary organic aerosols can enter the winter forest canopy under the influence of the radiometric photophoresis. The secondary aerosol photophoresis in the field of IR radiation, leaving the snow cover surface ("snow" photophoresis), is speculated to affect significantly the vertical transport of the secondary organic aerosols in the winter coniferous forest canopy. [ABSTRACT FROM AUTHOR]

Elastin‐like peptides (ELPs) are thermoresponsive biopolymers inspired by the characteristic repetitive sequences of natural elastin. As ELPs exhibit temperature‐dependent reversible self‐assembly, they are expected to be biocompatible thermoresponsive materials for drug delivery carriers. One of the most widely studied ELPs in this field is the repetitive pentapeptide, (VPGXG)n. We previously reported that phenylalanine‐containing ELP (Fn) analogs, in which the former Val residue of the repetitive sequence (VPGVG)n is replaced by Phe, show coacervation with a short chain length (n = 5). Owing to their short sequences, Fn analogs are easily modified in amino acid sequences via simple chemical synthesis, and are useful for investigating the relationship between peptide sequences and temperature responsiveness. In this study, we developed Fn analogs by replacing Phe residue(s) with other amino acids or introducing another amino acid at the N‐terminus. The temperature responsiveness of the Fn analogs changed drastically with the substitution of a single Phe residue, suggesting that aromatic amino acids play an important role in their self‐assembly. In addition, the self‐assembling ability of Fn was enhanced by increasing the bulkiness of the N‐terminal amino acids. Therefore, the N‐terminal residue was considered to be important for hydrophobicity‐induced intermolecular interactions between the peptides during coacervation. [ABSTRACT FROM AUTHOR]

In this study, we synthesized a reduced form of graphene oxide/copper oxide (rGO/CuO) nanocompounds produced at rGO wt. of 0.125%, 0.25%, 0.5% and 1%. The crystallinity indexes for rGO and rGO/CuO increased, and that for CuO decreased as the test temperatures increases, while the crystallinity indexes of rGO, CuO and rGO/CuO decreases with test periods increment. Measurement by dynamic light scattering reported average crystallite sizes of 0.7, 8.8, 25.4, 38.5 nm for 0.125 wt.% rGO/CuO, 0.25 wt.% rGO/CuO, 0.50 wt.% rGO/CuO and 1.0 wt.% rGO/CuO respectively. The electrochemical properties of the nanocomposites were checked. The rGO/CuO XRD peaks were 18.114320 Å, 225.1856 Å, 321.41740 Å, and 365.98290 Å, with 11.051640%, 0.461075%, 0.280083%, and 0.174259% for 2ϴ of 22.2031°, 43.5865°, 50.7050°, and 74.3729°, respectively. FTIR spectroscopy identified the existence of vibrational frequencies with pseudo-capacitance at 458 cm−1 which confirmed the presence of rGO-CuO nanoparticles. The voltammetry of rGO-CuO indicated the increment of electrochemical activity, large capacitance, and conduction in the reduced rGO/CuO composite. For rGO wt. of 0.125%, 0.25%, 0.5%, and 1.0%, the rGO/CuO composite specific capacitance was 561 F/g, 582 F/g, 597 F/g, and 611 F/g, respectively, which indicated good electrochemical performance. [ABSTRACT FROM AUTHOR]

In this paper, we are going to study the fluid around nanoparticles and their hydrodynamic size, completely. First, we obtain the complete set of relations of the velocity equations and the velocity vector field around a spherical nanoparticle. For this, we use Stokes' analytical method with boundary conditions. Using the velocity vector field equations, we obtain the stress tensor components on the sphere surface and the fluid resistance force on the nanoparticle. In the next step, we consider the hydrodynamic diameter of the particle to be the diameter at which the fluid no longer moves effectively with the particle, and we obtain a description for this quantity from the equations of velocity. We will examine and find a significant correlation between these values. In the experimental part, gold nanoparticles with a diameter of 12 nm are synthesized and characterized by the Turkevich method. The diameter and hydrodynamic diameter of particles are measured using an electron microscope (TEM) and dynamic light scattering (DLS). By numerical fitting the Fortran 90 programming code and using experimental data, we were able to estimate the relative velocity of the particles relative to the fluid. These studies can be a useful method for the experimental and theoretical study of resistance force and dispersion of nanoparticles in colloidal media and have many applications in experimental applications of nano colloids such as nanoparticle drug delivery.

Highlight 1. We developed a new DLS immunosensing technology for the rapid and sensitive detection of glycoprotein NT-proBNP. 2. The boronate affinity recognition amplified nanoparticle aggregation was designed to enable highly sensitive DLS transduction. 3. The fabricated DLS immunosensor exhibited ultrahigh sensitivity with an LOD of 7.4 fg mL−1, fast response time (

[Display omitted] • The copper flotation mechanism in the presence of ultrafine bubbles was investigated. • Freshly generated bubbles had a size of 600 nm, increasing to 5 μm after 25 days. • MNBs enhanced chalcopyrite and ore recoveries by 24.5 % and 7 %, respectively. • MNBs improved SIPX collector adsorption and kinetics by 73.8 % and 69.44 %. • SIPX sorption on chalcopyrite was chemisorption and physicochemical with and without MNBs. The present study systematically explores the relationship between chalcopyrite mono-mineral and copper-bearing ore flotation in the presence and absence of micro- and nano-bubbles (MNBs). Ultrafine bubbles were generated through a cavitation mechanism, and their stability, size, and zeta potential were monitored over a period of 0–25 days. Micro-flotation and batch rougher kinetic flotation experiments were carried out with and without ultrafine bubbles using a modified Hallimond tube and 2.5 L Denver® flotation cell, respectively. The results showed that the presence of MNBs improved the recovery of chalcopyrite mono-mineral and its ore by 24.5 % and 7 %, respectively. Furthermore, the adsorption behavior of sodium isopropyl xanthate (SIPX) collector at various concentrations was analyzed in the presence and absence of stable MNBs using UV–visible spectroscopy, FTIR analysis and kinetic models. The adsorption studies supported the micro-flotation findings, demonstrating that the presence of MNBs not only boosted collector adsorption on the chalcopyrite surface (by an average of 73.8 %) but also improved the adsorption kinetics (by 69.44 %). The sorption kinetics followed the pseudo 2nd order model in the presence of MNBs, while in the absence of MNBs, both pseudo 1st order and pseudo 2nd order models were observed. The sorption of SIPX onto chalcopyrite was identified as a chemisorption process in the presence of MNBs, whereas it was a physicochemical sorption in the absence of MNBs. [ABSTRACT FROM AUTHOR]

Proteins in ionic liquids (ILs) and deep eutectic solvents (DESs) have gained significant attention due to their potential applications in various fields, including biocatalysis, bioseparation, biomolecular delivery, and structural biology. Scattering approaches including dynamic light scattering (DLS) and small-angle X-ray and neutron scattering (SAXS and SANS) have been used to understand the solution behavior of proteins at the nanoscale and microscale. This review provides a thorough exploration of the application of these scattering techniques to elucidate protein properties in ILs and DESs. Specifically, the review begins with the theoretical foundations of the relevant scattering approaches and describes the essential solvent properties of ILs and DESs linked to scattering such as refractive index, scattering length density, ion-pairs, liquid nanostructure, solvent aggregation, and specific ion effects. Next, a detailed introduction is provided on protein properties such as type, concentration, size, flexibility and structure as observed through scattering methodologies. This is followed by a review of the literature on the use of scattering for proteins in ILs and DESs. It is highlighted that enhanced data analysis and modeling tools are necessary for assessing protein flexibility and structure, and for understanding protein hydration, aggregation and specific ion effects. It is also noted that complementary approaches are recommended for comprehensively understanding the behavior of proteins in solution due to the complex interplay of factors, including ion-binding, dynamic hydration, intermolecular interactions, and specific ion effects. Finally, the challenges and potential research directions for this field are proposed, including experimental design, data analysis approaches, and supporting methods to obtain fundamental understandings of complex protein behavior and protein systems in solution. We envisage that this review will support further studies of protein interface science, and in particular studies on solvent and ion effects on proteins. [Display omitted] [ABSTRACT FROM AUTHOR]

The aggregation of isotropic particles through interparticle reactions poses a challenge in control due to the ability of all surfaces to bind to each other, rendering the quantitative detection of such interparticle reactions based on particle size difficult. Here, we proposed a novel detection scheme for DNA utilizing an assembly of Janus particles (JPs) employing dynamic light scattering (DLS). DNA molecules are tethered on one hemisphere of the JP, while the other hemisphere retains its hydrophobic properties. Aggregation of JPs was induced by the sandwich hybridization of target DNA between them. The assembly of JPs was effectively monitored by the changes in hydrodynamic diameter detected by DLS, revealing that aggregation peaks at 2–3 particles and further reaction was hindered due to the inability of one hemisphere of the JP to interact with another JP. The target DNA demonstrated detectability at concentrations as low as several tens of pM to several nM using a digital sensing method. The two types of target DNA, such as simple (14 base pairs) and HIV-2 specific sequences (20 base pairs) were detectable at nM and pM levels, respectively. Moreover, we substantiated the robustness of our detection scheme through stoichiometric calculations based on an equilibrium model. The present detection mechanism was well explained based on the binding affinity of DNA hybridization. This detection method harnesses the anisotropic nature of JPs and represents the first detection approach based on aggregation. By altering the modification molecules on JPs to match target molecules, such as proteins and organic compounds, a wide range of versatile molecules can be detected using this scheme with high sensitivity. This underscores the broad applicability of the present method. [Display omitted] • Detection method based on aggregation of Janus particle (JP) through sandwich hybridization was proposed. • Assembly of 2–3 JP was observed using dynamic light scattering. • Target DNA was detectable at the pM-nM level in the range of 10−12-10−8 M. • Detection mechanism was demonstrated based on the stoichiometric calculation using equilibrium model. [ABSTRACT FROM AUTHOR]

Reverse micelles (RMs) are spontaneously organizing nanobubbles composed of an organic solvent, surfactants, and an aqueous phase that can encapsulate biological macromolecules for various biophysical studies. Unlike other RM systems, the 1-decanoyl- rac -glycerol (10MAG) and lauryldimethylamine-N-oxide (LDAO) surfactant system has proven to house proteins with higher stability than other RM mixtures with little sensitivity to the water loading (W 0 , defined by the ratio of water to surfactant). We investigated this unique property by encapsulating three model proteins – cytochrome c , myoglobin, and flavodoxin – in 10MAG/LDAO RMs and applying a variety of experimental methods to characterize this system's behavior. We found that this surfactant system differs greatly from the traditional, spherical, monodisperse RM population model. 10MAG/LDAO RMs were discovered to be oblate ellipsoids at all conditions, and as W 0 was increased, surfactants redistributed to form a greater number of increasingly spherical ellipsoidal particles with pools of more bulk-like water. Proteins distinctively influence the thermodynamics of the mixture, encapsulating at their optimal RM size and driving protein-free RM sizes to scale accordingly. These findings inform the future development of similarly malleable encapsulation systems and build a foundation for application of 10MAG/LDAO RMs to analyze biological and chemical processes under nanoscale confinement. [Display omitted] • 10MAG/LDAO RMs form ellipsoids that become more spherical with added water. • Proteins in 10MAG/LDAO RMs modify the particle size distribution to accommodate the native state. • The 10MAG/LDAO RM system is instructive for development of versatile systems for protein encapsulation. [ABSTRACT FROM AUTHOR]

The 0.1 M TODGA + 0.2 M DOHyA/n-DD phase was irradiated to various absorbed dose levels and the extraction behaviour of nitric acid and Nd(III) in the irradiated organic phases were studied. The organic phase was then subjected to dynamic light scattering studies to understand the aggregation behaviour in the organic phase. The results showed that the polar degradation products formed in the organic phase decreased the aggregation, while the higher homologue of n-DD enhanced aggregation. [ABSTRACT FROM AUTHOR]

Industrial hemp (Cannabis sativa L.), due to its bioactive compounds (terpenes and cannabinoids), has gained increasing interest in different fields, including for medical purposes. The evaluation of the safety profile of hemp essential oil (EO) and its encapsulated form (nanoemulsion, NE) is a relevant aspect for potential therapeutic applications. This study aimed to evaluate the toxicological effect of hemp EOs and NEs from cultivars Carmagnola CS and Uso 31 on three cell lines selected as models for topical and inhalant administration, by evaluating the cytotoxicity and the cytokine expression profiles. Results show that EOs and their NEs have comparable cytotoxicity, if considering the quantity of EO present in the NE. Moreover, cells treated with EOs and NEs showed, in most of the cases, lower levels of proinflammatory cytokines compared to Etoposide used as a positive control, and the basal level of inflammatory cytokines was not altered, suggesting a safety profile of hemp EOs and their NEs to support their use for medical applications.

The aim of the study was to obtain untreated and treated betulin colloidal particles and assess their effect on the viability, morphology, proliferation and cytokine secretion of human dermal fibroblasts. To improve bioavailability, betulin treatment was performed by an antisolvent precipitation technique. The average particle size after treatment in the aqueous dispersion decreased from 552.9 ± 11.3 to 278.2 ± 1.6 nm. Treated betulin colloidal particles showed no cytotoxicity up to a concentration of 400 µg·mL−1 in the colorimetric tetrazolium salt viability test (CCK-8). Moreover, the cell morphology was not changed in the presence of betulin colloidal particles at a concentration range from 0.78 to 400 µg·mL−1. The obtained results also show that betulin particles induce the secretion of the proinflammatory and angiogenesis-stimulating cytokine IL-8. However, further studies would be required to clarify the mechanism of IL-8 secretion induction.

We propose two convenient methods to quickly detect the presence of non-milk fat (palm oil) in butter, as well as to determine its amount in the product. For the first time, we have experimentally obtained the dependence of the size of drops of an alcoholic emulsion of oil or spread on the content of palm oil in it by the dynamic light scattering (DLS) method. We have also obtained the dependence of intensity ratio of the components of spread luminescence spectrum on palm oil content when excited at a wavelength λ = 266 nm. These results allowed us to propose two methods for determining the adulteration of butter with palm oil using DLS and measuring luminescence spectra. The two methods are physically independent but successfully supplement each other. DLS and luminescent methods for determining the proportion of palm oil give errors of no more than 10% and 6%, respectively.

Plastic waste is a global issue leaving no continents unaffected. In the environment, ultraviolet radiation and shear forces in water and land contribute to generating micro- and nanoplastic particles (MNPP), which organisms can easily take up. Plastic particles enter the human food chain, and the accumulation of particles within the human body is expected. Crossing epithelial barriers and cellular uptake of MNPP involves the interaction of plastic particles with lipids. To this end, we generated unilamellar vesicles from POPC (1-palmitoyl-2-oleoyl-glycero-3-phosphocholine) and POPS (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine) and incubated them with pristine, carboxylated, or aminated polystyrene spheres (about 1 µm in diameter) to generate lipid coronas around the particles. Lipid coronas enhanced the average particle sizes and partially changed the MNPP zeta potential and polydispersity. In addition, lipid coronas led to significantly enhanced uptake of MNPP particles but not their cytotoxicity, as determined by flow cytometry. Finally, adding proteins to lipid corona nanoparticles further modified MNPP uptake by reducing the uptake kinetics, especially in pristine and carboxylated plastic samples. In conclusion, our study demonstrates for the first time the impact of different types of lipids on differently charged MNPP particles and the biological consequences of such modifications to better understand the potential hazards of plastic exposure.

It is commonly true that a diluted colloidal suspension is more stable over time than a concentrated one because dilution reduces collision rates of the particles and therefore delays the formation of aggregates. However, this generalization does not apply for some engineered ligand-coated nanoparticles (NPs). We observed the opposite relationship between stability and concentration of NPs. We tested 4 different types of NPs: CdSe-11-mercaptoundecanoic acid, CdTe-polyelectrolytes, Ag-citrate, and Ag-polyvinylpyrrolidone. The results showed that dilution alone induced aggregation and subsequent sedimentation of the NPs that were originally monodispersed at very high concentrations. Increased dilution caused NPs to progressively become unstable in the suspensions. The extent of the dilution impact on the stability of NPs is different for different types of NPs. We hypothesize that the unavoidable decrease in free ligand concentration in the aqueous phase following dilution causes detachment of ligands from the suspended NP cores. The ligands attached to NP core surfaces must generally approach exchange equilibrium with free ligands in the aqueous phase; therefore, ligand detachment and destabilization are expected consequences of dilution. More studies are necessary to test this hypothesis. Because the stability of NPs determines their physicochemical and kinetic behavior including toxicity, dilution-induced instability needs to be understood to realistically predict the behavior of engineered ligand-coated NPs in aqueous systems. Environ Toxicol Chem 2018;37:1301-1308. © 2018 SETAC.

Background and aim: Epithelial ovarian cancer has the deadliest prognosis amongst gynaecological cancers, warranting an unmet need for newer drug targets. Based on its anticancer as well as abortifacient potential, Moringa oleifera Lam. root was hypothesized to have some implications in follicle stimulating hormone receptor (FSHR) dependent cancers like epithelial ovarian cancer. Experimental procedure: Effect of Moringa oleifera Lam. root extract (MRE) was studied in epithelial ovarian cancer cell line through in vitro studies viz. MTT assay, clonogenic assay, cell cycle analysis, flow cytometry, western blot analysis, immunocytochemical analysis of FSHRand c-Myc expression and in vivo studies viz. effect of MRE in mice model of ovarian carcinoma. The structure of the active compound of MRE was elucidated following solvent extraction, purification through column chromatography, preparative TLC and bioactivity guided structural identification through 1H-NMR, 13C-NMR, DEPT-135, ESIMS,FT-IR spectrophotometry, UV–vis–NIR spectrophotometry and DFT study. Results and conclusion: Crude MRE displayed cytotoxic activity, induced apoptosis, and attenuated expression of FSHR and c-Myc in ovarian cancer cell line OAW42. MRE also attenuated expression of CD31, FSHR, and c-Myc in tumour xenograft mouse model. Finally, the active compound purified from ethyl acetate-n-hexane subfraction ofMRE, that attenuated viability of ovarian carcinoma cell lines and reduced FSHR and c-Myc expression, was identified as a naturally hydrated-trifattyglyceride, showing aDFT-optimized folded amphipathic structure for easy transportation through hydrophilic and hydrophobic regions in a biological system, indicating its immense therapeutic relevance in epithelial ovarian carcinoma.

In the paper, modification of the electrophoretic light scattering (ELS) method for improving an accuracy of determining the electrophoretic mobility and zeta potential of nanoparticles in colloidal systems has been put forward. The modification included the creation of an original experimental setup operating in the heterodyne mode using a multimode fiber at the input of the recording unit, an increase in the signal-to-noise ratio of the system, and also an expansion of ranges of nanoparticles’ key parameters: sizes, electrical conductivity, concentration in solution. The theoretical substantiation for processing the scattering signal of polydisperse colloidal solutions of nanoparticles and calculating the electrophoretic mobility and zeta potential of colloidal systems was given. The high accuracy of the measured parameters was achieved, in comparison with the data obtained from the ZetaSizer Nano commercial device.

The rapid classification of micro-particles has a vast range of applications in biomedical sciences and technology. In the given study, a prototype has been developed for the rapid detection of particle size using multi-angle dynamic light scattering and a machine learning approach by applying a support vector machine. The device consisted of three major parts: a laser light, an assembly of twelve sensors, and a data acquisition system. The laser light with a wavelength of 660 nm was directed towards the prepared sample. The twelve different photosensors were arranged symmetrically surrounding the testing sample to acquire the scattered light. The position of the photosensor was based on the Mie scattering theory to detect the maximum light scattering. In this study, three different spherical microparticles with sizes of 1, 2, and 4 μm were analyzed for the classification. The real-time light scattering signals were collected from each sample for 30 min. The power spectrum feature was evaluated from the acquired waveforms, and then recursive feature elimination was utilized to filter the features with the highest correlation. The machine learning classifiers were trained using the features with optimum conditions and the classification accuracies were evaluated. The results showed higher classification accuracies of 94.41%, 94.20%, and 96.12% for the particle sizes of 1, 2, and 4 μm, respectively. The given method depicted an overall classification accuracy of 95.38%. The acquired results showed that the developed system can detect microparticles within the range of 1–4 μm, with detection limit of 0.025 mg/ml. Therefore, the current study validated the performance of the device, and the given technique can be further applied in clinical applications for the detection of microbial particles.

There is a dogma within whey protein modification, which dictates the necessity of pretreatment to enzymatic cross-linking of β-lactoglobulin (β-Lg). Here microbial transglutaminase (MTG) cross-linked whey proteins and β-Lg effectively in 50 mM NaHCO3, pH 8.5, without pretreatment. Cross-linked β-Lg spanned 18 to >240 kDa, where 6 of 9 glutamines reacted with 8 of 15 lysines. The initial isopeptide bond formation caused loss of β-Lg native structure with t1/2 = 3 h, while the polymerization occurred with t1/2 = 10 h. Further, cross-linking effects on protein carbohydrate interaction have been overlooked, leaving a gap in understanding of these complex food matrices. Complexation with alginate showed that β-Lg cross-linking decreased onset of particle formation, hydrodynamic diameter, stoichiometry (β-Lg/alginate) and dissociation constant. The complexation was favored at higher temperatures (40 °C), suggesting that hydrophobic interactions were important. Thus, β-Lg was cross-linked without pretreatment and the resulting polymers gave rise to altered complexation with alginate.

Surface ligands are essential tools for the stabilization of colloidal nanoparticles (NPs) in solvents. However, knowledge regarding the effects of the ligand shell, especially the ligand length, is insufficient and controversial. Here we demonstrate solution‐based experiments on n‐alkylphosphonate‐capped TiO2 NPs to investigate the effects of ligand length and solution temperature on colloidal stability. A robust ligand‐exchange process is achieved that draws free ligands and impurities away from the colloidal solution. In the case of 8 nm anatase NPs in toluene, the dodecylphosphonate ligand provided better colloidal stability than all the other n‐alkylphosphonate ligands. In addition, relaxation studies suggested there is kinetic hysteresis in the dispersion/agglomeration transition. The proposed method is applicable to a wide range of surface ligands designed to maximize the colloidal stability of NPs. [ABSTRACT FROM AUTHOR]

We designed three cholesterol-modified carboxylated pullulan (CHSP) polymers modified with different degrees of substitution (DS). Nuclear magnetic resonance (NMR) was used to characterize CHSP polymer and calculate the DS, which were 2.12%, 4.36% and 6.05% for CHSP1, CHSP2 and CHSP3. The particle sizes identified by dynamic light scattering (DLS) were approximately 229.4 nm, 185.1 nm and 178.0 nm.The mitoxantrone (MTO) loadings of three nanoparticles were 5.28%, 6.71% and 7.68%. At pH 6.8, 72 hours later, the drug release rates were 95.42%, 86.88%, and 80.16%. In the weakly acidic environment, the drug release rate was significantly accelerated but still showed three types of nanoparticles and hydrophobic substitution degree-related slow release characteristics. In the cytotoxicity experiments, it was found that the inhibitory effect of the three nanoparticles on hepatoma cells is related to the degree of hydrophobic substitution, and the nanoparticles with the lowest hydrophobic substitution degree have the strongest inhibitory effect. [ABSTRACT FROM AUTHOR]

Zinc Sulphide (ZnS) nanoparticles were successfully synthesized by the cost effective Chemical co-precipitation method at room temperature. The structural studies were carried out using X-ray diffraction (XRD), Dynamic Light Scattering (DLS) studies were used to analyze particle size, Functional group, optical properties and Morphological study were characterized by FTIR, UV-Vis, PL and Scanning Electron Microscope (SEM). In this work also probe the crystallite development in nanostructure ZnS by X-ray peak broadening analysis. The individual contributions of small crystallite sizes and lattice strain to the peak broadening in Uncapped and L-Cysteine Capped ZnS nanoparticles were analyzed using Modified Williamson-Hall (W-H) analysis. The modified form of W-H plot assuming the uniform deformation model (UDM), uniform stress deformation model (USDM) and uniform deformation energy density model (UDEDM). The root mean square (RMS) lattice strain calculated from the interplanar spacing and the strain estimated from USDM and UDEDM are different due to consideration of anisotropic crystal nature. [ABSTRACT FROM AUTHOR]

Humic and fulvic acids derived from South Ural lignite are studied. The composition of the coal, humic acids, and fulvic acids are characterized by technical and elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and CP/MAS 13C NMR spectroscopy. A method is proposed for extracting fulvic acids from lignite.by means of an aqueous hydrochloric-acid solution of n-butanol. It is established that fulvic acids are characterized by higher content of oxygen-bearing aliphatic groups with a predominance of carboxylic acids and complex esters, while humic acids have a higher content of carbon, hydrogen, and aromatic fragments. Dynamic light scattering shows that colloidal aggregations of fulvic acids in water are disperse systems with bimodal (at low concentrations) and monomodal (at higher concentrations) size distributions of nanoparticles and submicroparticles. The low negative values of the zeta potential for aqueous fulvic acid colloids indicate instability and a tendency to complex formation. [ABSTRACT FROM AUTHOR]

Dynamic light scattering (DLS) has been proved to be a feasible method to measure the flowing aerosol particle size distribution (PSD). However, since the flowing aerosol particle is affected by the Brownian motion diffusion and the uniform translational motion relative to optical scattering volume, its inversion is more complex than traditional DLS. In this paper, Tikhonov and truncated singular value decomposition (TSVD) are used to invert aerosol particles with different noise levels and flow velocities. After the analysis of the influencing factors, the results showed that: For unimodal small aerosol particles, in the case of low flow velocity, the inversion errors of TSVD are smaller than those of Tikhonov. For unimodal particles with high flow velocity, the increase in flow velocity will weaken the PSD information distribution of DLS measurement, which becomes another factor affecting PSD inversion besides noise. In addition, truncation of singular values further results in loss of PSD information distribution. The inversion accuracy of TSVD decreases obviously. Tikhonov adopts the strategy of modifying the small singular value, which will not lose all the PSD information distribution carried by the singular value while reducing the influence of noise. In this case, Tikhonov is more suitable. For bimodal aerosol particles, the resolution of the DLS particle sizing measurement is limited by the noise mixed in the intensity autocorrelation function data and the inherently lower information content of the data. On this basis, the influence of flow velocity will further cause the loss of data information. Tikhonov has better performance indicators and stronger bimodal resolution. The experimental results are in good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

Nanocellulose synthesised from the diversified natural fibres sources has several times higher strength and modulus than macro, long fibres. This work attempts to engage the chemical synthesis route majorly and marginally through mechanical techniques to produce nanocellulose from okra fibre by following systematic procedural steps. The nanocelulose has a mean diameter of 540.7 nm. SEM measured the minimum agglomerated mass of carbon nanofiber (CNF), and its value was 0.41 μm. Cotton fabric (CF) was considered in this work for better settlement of nanocellulose (NC). Sonication was done with the intermittent variation of amplitude and pulse/cycle at each weight fraction of reinforcement in the hardener. Huntsman grade aerospace epoxy resin was used to fabricate the composite laminae with the various reinforcements. The highest tensile strength, modulus of 28.52 MPa, 0.254 GPa was achieved at a weight fraction of 0.04% CNF, 0.39% NC, respectively. Hybrid composites (CF+NC+CNF) flexural strength, the modulus was 116.48 MPa, 4.21 GPa. At 0.11 Wf % of NC-epoxy composites showed the highest impact strength of 2.19 kJ/m2 and is more than hybrid composites experimented within this work. Heat flow, thermal degradation characteristics of reinforcements, matrix, and composites are characterised using Differential Scanning Calorimetry, Thermogravimetric Analysis. [ABSTRACT FROM AUTHOR]

Purposes: In reducing capillary electrophoresis sodium dodecyl sulfate (CE-SDS) analysis of a monoclonal antibody (mAb-1), the peak area ratio of heavy chain (HC) to light chain (LC) was out of balance, while multiple artifact peaks were observed following the migration of HC. The main purposes of this study were to describe the techniques utilized to eliminate this artifact and clarify the root cause for this interesting phenomenon. Methods: We optimized the CE-SDS analysis of mAb-1 by a vairety of techniques including changing the concentration of protein or replacing SDS with a more hydrophobic surfactant (i.e., sodium hexadecyl sulfate (SHS) or sodium tetradecyl sulfate (STS) instead of SDS) in sample and/or the sieving gel buffer. Dynamic light scattering (DLS) and reversed phase high-performance liquid chromatography (RP-HPLC) were used to study the protein-surfactant complex. Results: The artifact could be partially mitigated by reducing the protein concentration and replacing SDS with SHS or STS in the sample and/or the sieving gel buffer solutions. Due to replacing a more hydrophobic surfactant, the HC-surfactant complex formed was more resistant to dissociation, preventing additional hydrophobic HC-HC interaction and aggregation, thus eliminating the artifact problem. Conclusions: DLS and RP-HPLC are powerful supplementary techniques in characterizing the protein-surfactant complex, and hydrophobic surfactants such as SHS and STS could afford more normal electropherograms during the analysis of mAbs. [ABSTRACT FROM AUTHOR]

The present study aimed to explore the sensitising capability of the anticancer agents, gemcitabine (GEM) and oxaliplatin (OXA), encapsulated in a novel SLN (GEM:OXA-SLN) against the ovarian cancer cell lines. A novel SLN, prepared using hot homogenisation by mixing phosphatidylcholine, cholesterol, tween 80, and oleic acid, was characterised using Transmission Electron Microscope and zetasizer. The anticancer activities and the underlying molecular mechanisms of GEM:OXA-SLN were investigated. The average z-diameter of the homogeneous spherical GEM:OXA-SLN was (70.33 ± 0.70) nm with zeta potential (–7.69 ± 0.61) mV. GEM:OXA-SLN significantly inhibited the viability of ovarian cancer cells in a dose-dependent manner within 24 h. It also triggered the induction of autophagy cellular death, suppression of multidrug resistance efflux pump and inhibition of heat shock protein (Hsp90). The encapsulation of GEM and OXA in SLN improved the efficacy of the drugs and diminished the ovarian cancer cell's resistance. [ABSTRACT FROM AUTHOR]

It was found earlier that the synthetic fragment corresponding to the 60–76 sequence of the extracellular domain of the receptor for advanced glycation end products (RAGE) had a protective effect on animal and cellular models of Alzheimer's disease. It was proposed that this effect was mediated via the interaction of the peptide with beta-amyloid (Aβ), which was one of the RAGE ligands, by inhibiting the formation of toxic Aβ oligomers. The aim of this study was an application of physicochemical methods to an investigation of the ability of the 60–76 peptide to prevent the Aβ40 oligomerization in solution in comparison with the nonprotective 65–76 truncated peptide. The dynamics of the formation of the Aβ40 fibrils in the presence of the peptides was evaluated using thioflavin T. The relative sizes of oligomers were determined by dynamic light scattering. The peptide binding to Aβ40 was examined by fluorescence titration. We demonstrated by the two methods that the peptide corresponding to the 60–76 sequence of RAGE considerably inhibited (by more than 90%) the formation of oligomers and fibrils of Aβ40 distinct from the 65–76 peptide. In addition, we found that the protective effect of the peptides and their ability to inhibit the Aβ40 oligomerization did not correlate with their binding to the monomeric/tetrameric Aβ40. We confirmed in vitro the hypothesis that the protective activity of the synthetic 60–76 fragment of RAGE was associated with its ability to inhibit the Aβ oligomerization. [ABSTRACT FROM AUTHOR]

Chemically exfoliated nanosheets have been extensively employed as functional nanofillers for the fabrication of polymer nanocomposites due to their remarkable electrical, magnetic and optical properties. However, achieving a good dispersion of charged nanosheets in polymer matrix, which will determine the performance of polymer nanocomposites, remains a challenge. Herein, we investigated the dispersion and aggregation behavior of negatively charged Ca2Nb3O10 (CNO) perovskite nanosheets in negatively charged sodium alginate (SA) aqueous dispersion using dynamic light scattering (DLS). When CNO nanosheets meet with SA, aggregation and coagulation inevitably occurred owing to the absorption of SA on nanosheets. By controlling the electrostatic attraction between positively charged poly(ethylene imine) (PEI) and negatively charged SA, the charge density and hydrodynamic size of SA can be tuned to enable the good dispersion of CNO nanosheets in SA. This result may provide a new strategy to achieve the good dispersion of charged nanosheets in charged polymers for the rational design of multifunctional nanocomposites. [ABSTRACT FROM AUTHOR]

A nanocarrier was obtained by coating the natural clinoptilolite particle surface with a phosphatidylcholine layer. The shell effective size does not exceed the thickness of the phospholipid molecular layer, which was confirmed by UV spectrometry and molecular mass spectrometry. The hydrodynamic diameter of the formulated nanocarrier, which was determined by dynamic light scattering, is smaller than the clinoptilolite core size. This effect is assumed to be caused by the phospholipid shell, which reduces the aqueous medium friction. The nanosize of the formulated nanocarrier, the natural clinoptilolite core, and the phospholipid shell together allow a combination of fruitful features that can be used for the fabrication of multifunctional platforms for the delivery of biologically active substances, bioimaging, or as a basis for biosensors. [ABSTRACT FROM AUTHOR]

The mechanism of flocculation of silica hydrosol (Ludox TM-40) with polyacrylamide (Magnafloc brand) was studied by viscometry, turbidimetry, and dynamic light scattering (DLS). The existence of two stages of flocculation is shown: the formation of primary floccules according to the mechanism of heteroadagulation of silica nanoparticles on the surface of polymer microglobules and enlargement of polymer associates with the formation of sedimentation-unstable composite particles. The transition from the first step of the process to the second step is characterized by the value of the critical flocculation concentration (CCF). The intensity of flocculation increases with an increase in the molecular weight of polyacrylamide and the degree of hydrolysis of amide groups (anionic nature of the polymer). [ABSTRACT FROM AUTHOR]

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Neuronal calcium sensors (NCSs) are the family of EF-hand proteins mediating Ca2+-dependent signaling pathways in healthy neurons and neurodegenerative diseases. It was hypothesized that the calcium sensor activity of NCSs can be complemented by sensing fluctuation of intracellular zinc, which could further diversify their function. Here, using a set of biophysical techniques, we analyzed the Zn2+-binding properties of five proteins belonging to three different subgroups of the NCS family, namely, VILIP1 and neurocalcin-δ/NCLD (subgroup B), recoverin (subgroup C), as well as GCAP1 and GCAP2 (subgroup D). We demonstrate that each of these proteins is capable of coordinating Zn2+ with a different affinity, stoichiometry, and structural outcome. In the absence of calcium, recoverin and VILIP1 bind two zinc ions with submicromolar affinity, and the binding induces pronounced conformational changes and regulates the dimeric state of these proteins without significant destabilization of their structure. In the presence of calcium, recoverin binds zinc with slightly decreased affinity and moderate conformational outcome, whereas VILIP1 becomes insensitive to Zn2+. NCALD binds Zn2+ with micromolar affinity, but the binding induces dramatic destabilization and aggregation of the protein. In contrast, both GCAPs demonstrate low-affinity binding of zinc independent of calcium, remaining relatively stable even at submillimolar Zn2+ concentrations. Based on these data, and the results of structural bioinformatics analysis, NCSs can be divided into three categories: (1) physiological Ca2+/Zn2+ sensor proteins capable of binding exchangeable (signaling) zinc (recoverin and VILIP1), (2) pathological Ca2+/Zn2+ sensors responding only to aberrantly high free zinc concentrations by denaturation and aggregation (NCALD), and (3) Zn2+-resistant, Ca2+ sensor proteins (GCAP1, GCAP2). We suggest that NCS proteins may therefore govern the interconnection between Ca2+-dependent and Zn2+-dependent signaling pathways in healthy neurons and zinc cytotoxicity-related neurodegenerative diseases, such as Alzheimer's disease and glaucoma. [ABSTRACT FROM AUTHOR]