Low Zeta Potential Research Articles

Nanoemulsion-Based Orodispersible Film Formulation of Guava Leaf Oil for Inhibition of Oral Cancer Cells.

Among natural sources, guava leaf oil (GLO) has emerged as a potential anticancer agent. However, its limited water solubility poses a significant challenge for its use. Oil-in-water nanoemulsions are used to address the limitation of water solubility of GLO prior to its incorporation into orodipersible films. Nanoemulsions containing GLO:virgin coconut oil (VCO) at a ratio of 50:50 to 70:30 presented a small droplet size of approximately 50 nm and a relatively low zeta potential. GLO:VCO at a ratio of 70:30 was selected for incorporation into sodium alginate film at various concentrations ranging from 1% to 30% w/w. Tensile strength and elongation at break relied on the concentration of nanoemulsions as well as the internal structure of films. Fourier transform infrared spectroscopy revealed that GLO was compatible with sodium alginate. Film containing 2% w/w of nanoemulsions (2G_ODF) exhibited effective in vitro antioral cancer activity, with an IC50 of 62.49 ± 6.22 mg/mL; furthermore, its anticancer activity showed no significant difference after storage at 25 °C for 1 year. Moreover, 2G_ODF at IC60 arrested colony formation and cell invasion. There is also evidence that cell death occurred via apoptosis, as indicated by nuclear fragmentation and positive Annexin-V staining. These findings highlight the potential of orodispersible films containing GLO nanoemulsions as a prospective oral anticancer agent.

Structure and characterization of Tremella fuciformis polysaccharides/whey protein isolate nanoparticles for sustained release of curcumin.

Whey protein isolate (WPI) nanoparticles can be used in a strategy to improve the bioavailability of curcumin (CUR) although they are generally not stable. Previous studies have indicated that Tremella fuciformis polysaccharides (TFPs) can increase the stability of WPI. This work investigated systematically the characterization and structure of TFP/WPI nanoparticles with differing CUR content. The highest encapsulation efficiency of CUR was 98.8% and the highest loading content was 47.88%. The TFP-WPI-CUR with 20 mg mL-1 of CUR had the largest particle size (653.67 ± 21.50 nm) and lowest zeta potential (-38.97 ± 2.51 mV), and the capacity to retain stability across a variety of salt ion and pH conditions for 21 days. According to the findings of the structural analysis, the addition of TFPs and CUR rendered the structure of WPI amorphous, and the β-sheet was reduced. Finally, in vitro release indicated that the TFP-WPI-CUR combination could regulate the sustained release behavior of CUR. In summary, TFP-WPI nanoparticles can be used as carriers for the delivery of CUR, and can expand applications of CUR in the functional food, dietary supplement, pharmaceutical, and beverage industries. © 2023 Society of Chemical Industry.

Imidazo-Pyrazole-Loaded Palmitic Acid and Polystyrene-Based Nanoparticles: Synthesis, Characterization and Antiproliferative Activity on Chemo-Resistant Human Neuroblastoma Cells.

Neuroblastoma (NB) is a childhood cancer, commonly treated with drugs, such as etoposide (ETO), whose efficacy is limited by the onset of resistance. Here, aiming at identifying new treatments for chemo-resistant NB, the effects of two synthesized imidazo-pyrazoles (IMPs) (4G and 4I) were investigated on ETO-sensitive (HTLA-230) and ETO-resistant (HTLA-ER) NB cells, detecting 4I as the more promising compound, that demonstrated IC50 values lower than those of ETO on HTLA ER. Therefore, to further improve the activity of 4I, we developed 4I-loaded palmitic acid (PA) and polystyrene-based (P5) cationic nanoparticles (P5PA-4I NPs) with high drug loading (21%) and encapsulation efficiency (97%), by a single oil-in-water emulsification technique. Biocompatible PA was adopted as an emulsion stabilizer, while synthesized P5 acted as an encapsulating agent, solubilizer and hydrophilic-lipophilic balance (HLB) improver. Optic microscopy and cytofluorimetric analyses were performed to investigate the micromorphology, size and complexity distributions of P5PA-4I NPs, which were also structurally characterized by chemometric-assisted Fourier transform infrared spectroscopy (FTIR). Potentiometric titrations allowed us to estimate the milliequivalents of PA and basic nitrogen atoms present in NPs. P5PA-4I NPs afforded dispersions in water with excellent buffer capacity, essential to escape lysosomal degradation and promote long residence time inside cells. They were chemically stable in an aqueous medium for at least 40 days, while in dynamic light scattering (DLS) analyses, P5PA-4I showed a mean hydrodynamic diameter of 541 nm, small polydispersity (0.194), and low positive zeta potentials (+8.39 mV), assuring low haemolytic toxicity. Biological experiments on NB cells, demonstrated that P5PA-4I NPs induced ROS-dependent cytotoxic effects significantly higher than those of pristine 4I, showing a major efficacy compared to ETO in reducing cell viability in HTLA-ER cells. Collectively, this 4I-based nano-formulation could represent a new promising macromolecular platform to develop a new delivery system able to increase the cytotoxicity of the anticancer drugs.

Effect of the interaction of nisin Z with various polysaccharides on its antibacterial activity

The effect of various polysaccharides commonly used as thickening or gelling agents in foods on the antibacterial activity of nisin Z was investigated. Addition of 1 g.L−1 sodium alginate in tryptic soy broth resulted in a four-fold increase of minimal inhibitory (MIC) and bactericidal (MBC) concentrations of nisin Z against Listeria innocua ATCC 33090 and Kocuria rhizophila ATCC 9341, while the addition of citrus pectin or various exopolysaccharides (Leuconostoc mesenteroides P35 exopolysaccharides, low (9–11 kDa) or medium (60–76 kDa) molecular weight dextran from Ln. mesenteroides and 2 kefirans (extracted from kefir grains provided by Crokfun or Kefiralia)) did not increase MIC and MBC of nisin Z against these bacteria. Zeta potential determination at pH 7 of the nisin Z, bacteria and polysaccharides allowed us to observe that only nisin Z had a slightly positive zeta potential, while the bacteria, sodium alginate and highly methoxylated citrus pectin zeta potentials were lower than −20 mV and zeta potentials of all exopolysaccharides were between 0 and - 10 mV. It was thus proposed that anionic sodium alginate, which is the only polysaccharide having a lower zeta potential than both bacteria, forms complexes stabilized by electrostatic interactions with oppositely charged nisin Z, thereby limiting the quantity of “free” nisin Z interacting with nisin-susceptible bacteria. This hypothesis was substantiated by the observation of nisin Z - sodium alginate aggregation at pH 7 and the estimation of the apparent affinity of sodium alginate for “free” nisin Z and immobilized nisin Z by partition experiments and by surface plasmon resonance analysis, respectively. This study thus provides useful information for food formulation regarding the effect of different polysaccharides on nisin Z antibacterial activity and some understanding of how interactions between nisin Z, polysaccharides, and nisin Z - sensitive bacteria are explanatory.

Effects of Cr(VI) oxyanion, humic acid and solution chemistry on the aggregation and colloidal stability of green synthesized chlorapatite nanoparticles

Aggregation is a crucial process determining the fate, mobility and ecological risks of nanomaterials. Chlorapatite nanoparticles (nClAP) exhibit widely applications in environmental remediation and consequently will inevitably enter aquatic systems. However, the aggregation characteristics of nClAP are still mostly uncovered. This study investigated the aggregation kinetics and colloidal stability of nClAP as a function of pH, humic acid (HA), Cr(VI) oxyanions, monovalent and divalent electrolytes. Results showed that pH values from 5 to 9 had a notable impact on the aqueous behaviors of nClAP. The addition of HA made the zeta potential (ZP) of nClAP more negative and thus enhanced nClAP stability through electrostatic and steric effects. Similarly, the adsorption of Cr(VI) on the surface of nClAP created a physical barrier and negative charge, improving the stability of nClAP by inducing steric force. Lower ZP and hydrodynamic diameter (HDD) reflected that the enhanced stability of nClAP by HA was more significant than Cr(VI). In comparison, the presence of Ca2+ ions were more effective than monovalent Na + ions in promoting the aggregation of nClAP. The classical DLVO theory incorporating the steric repulsion were used to interpret the aggregation and dispersion of nClAP, making it was easier to overcome energy barriers and agglomerate. This study provides new mechanistic insights which could help better understand the effects of Cr(VI) oxyanions and HA on nClAP's colloidal stability.

Fabrication of NiCo2S4/N-deficient g-C3N4 for efficient photocatalytic H2 production

Graphitic carbon nitride (g-C3N4) as an ideal visible light active photocatalyst has received much attention in the fields of photocatalytic H2 production, pollutant degradation, and CO2 reduction due to its excellent stability and environment friendly features. In this work, g-C3N4 with N-defects (C3N4-x) was obtained through a KOH-assisted hydrothermal strategy followed by a freeze drying and an annealing process using urea as the starting materials. The investigation shows that C3N4-x has a narrower band gap of 2.7 eV, lower zeta potential of -25.9 mV, more negative CB position of -0.97 V and active sites compared to ordinary bulk g-C3N4, these all contribute to the improved activity for photocatalytic H2 evolution. Furthermore, the activity of C3N4-x was further improved by introduction of H2 evolution co-catalyst NiCo2S4 on its surface via a solvent evaporation method. The H2 evolution rate of 20% NiCo2S4/C3N4-x can reach up to 15673 μmol·g−1·h−1 under a 300 W Xe lamp in TEOA solution, which is 92 times for g-C3N4 (170 μmol·g−1·h−1), 46 times for C3N4-x (340 μmol·g−1·h−1), respectively. It is found that the introduction of NiCo2S4 can increase the number of active sites, prolong the carrier lifetime, decrease the H2 evolution potential of the sample, and improve contact between reaction solution and catalyst surface. This work suggests that transition bimetallic sulfides might be suitable H2 evolution co-catalyst for the g-C3N4-based photocatalytic H2 production systems.

Transient dynamic electrophoresis of a spherical colloidal particle.

A general theory is presented for the transient dynamic electrophoresis of a spherical colloidal particle in an electrolyte solution under a suddenly applied oscillating electric field. An approximate analytic expression is derived for the transient dynamic electrophoretic mobility, which is applicable for low particle zeta potentials and arbitrary Debye length. It is found that the electrophoretic mobility shows a damped oscillation, approaching its final value, unlike the case where a step electric field is applied.

Interfacial moduli at large strains and stability of emulsions stabilised by plant proteins at high bulk shear rates

For several commercial plant-protein stabilisers, we investigated how surface shear and dilatational properties affect dynamic emulsion stability under high bulk shear conditions. Potato protein isolates Potato-1 (rich in patatin) and Potato-2 (rich in protease inhibitors) showed a stiffer, more solid-like response than soy and pea protein isolates in large amplitude oscillatory surface shear. Soy protein isolates had the weakest interfaces and showed a more liquid-like behaviour. Potato-2 had the highest stiffness and most brittle interface in large amplitude oscillatory dilatational deformations. It also showed more significant softening, evident from both the shear and dilatational Lissajous plots. Only the Potato-1-stabilised emulsion was stable against coalescence at high bulk shear (although that emulsion was unstable against flocculation because of its low zeta potential). The low stiffness imparted to the interface by the pea and soy protein isolates was not suitable for preparing emulsions with high dynamic stability. In the linear regime, both Potato-1 and Potato-2 produced interfaces with similar surface shear moduli, and in dilatation, Potato-2 gave a higher modulus. The lower stability of the Potato-2 emulsions appears to be linked to the higher brittleness and stronger softening effect for increasing deformation amplitude. Both in surface shear and dilatation, the maximum linear strain for the Potato-1-stabilised interface is larger. The lower maximum linear strain and stronger softening effect at high deformations for Potato-2 may have resulted in more disruption of the interfacial microstructure, and this induced (partial) coalescence.

Potential industrial approach for efficient dispersion of silica fume: Rapid wet-grinding dispersion technique

Silica fume (SF) has been used extensively in buildings with high strength and durability requirements, but it must be densified prior to transport, causing it to lose its original pozzolanic activity. The common methods of SF dispersion are stirring, soaking and ultrasonication, but there is still a lack of an efficient and fast dispersion method. In this study, a rapid wet-grinding dispersion technique was designed to achieve the dispersion of densified silica fume (DSF) within 5 min, and the results were better than stirring and ultrasonic dispersion. The results of the study show that the wet-ground silica fume (WSF) slurry has a lower zeta potential, electrical conductivity and better stability. Wet grinding dispersion restores the balling effect of SF, with WSF slurry flow improving by 139% compared to plus DSF, and the fluidity of WSF_8% improving by 21% with lower apparent viscosity and yield stress. Additionally, WSF has superior pozzolanic activity, with a 16% increase in compressive strength at 28 days and a 62% increase in C-S-H gel content at 28 days. A novel technique for the effective dispersion of silica fume was presented in this study.

Effect of starch type on the physicochemical and emulsifying properties of amorphous starch–whey protein isolate mixtures

Starch from several plant sources, namely Japonica rice starch (JRS), waxy rice starch (WRS), corn starch (CS), wheat starch (WS), pea starch (PeS), potato starch (PtS), and tapioca starch (TS), were separately pasted into amorphous mixtures with whey protein isolate (WPI). The physicochemical and emulsifying properties of the seven amorphous starch–WPI mixtures were characterized. Each starch–WPI mixture showed a lower fluorescence intensity than that of WPI alone. The mixtures containing PtS, PeS, CS, and WS, which have higher amylose content, had lower fluorescence intensities than the other mixtures. The PeS-, CS-, and WS-WPI mixtures had lower zeta-potentials and larger particle sizes, contained remnants of starch granules, and exhibited a low paste viscosity. The droplet sizes of emulsions stabilized with the amorphous starch–WPI mixtures ranged from 2.82 to 7.04 μm. The emulsions stabilized with either PtS-, PeS-, CS-, or WS-WPI mixtures had smaller droplet sizes and higher storage modulus (G′) values and showed no creaming after storage for 30 d, whereas severe creaming occurred in the emulsions containing WRS-, TS-, or JRS-WPI mixtures. Microscopic imaging revealed that the mixtures-stabilized emulsions were composed of WPI-adsorbed spherical droplets with starch in the continuous phase.

Tailoring hydroxyapatite morphology via the effect of divalent cations on the hydrolysis of α-TCP: Oriented crystal growth towards the application in water treatment

The hydrothermal synthesis method to produce calcium hydroxyapatite (HA) of controlled morphology without the use of organic additives is developed in this study. The influence of smaller (Mg2+, Mn2+) and larger (Sr2+, Ba2+) ions on the hydrolysis of α-TCP and crystal growth of HA particles was investigated. It was revealed that both the hydrothermal synthesis conditions (temperature, time) and the nature and concentration of the foreign ion affected the phase purity and morphology of the final products. Of all the ions investigated, Mn2+ had the highest, and Sr2+ had the lowest inhibiting effect on the hydrolysis process of α-TCP. Under certain synthesis conditions, we were able to obtain samples consisting of plate-like or rod-like particles only. The dye adsorption test revealed that the adsorption of plate-like particles for cationic dyes was more efficient, possibly, due to the higher surface area (SBET). Upon normalizing the test results to SBET, it became apparent that the electrostatic attraction between HA particles and dye molecules also impacted the adsorption efficiency. Rod-like particles had a higher ratio of exposed (a,m)-planes and hence lower zeta potential, resulting in increased adsorption of the cationic dye.

High performance forward osmosis membrane with ultrathin hydrophobic nanofibrous interlayer

The novel thin film composite (TFC) forward osmosis (FO) membrane with electrospinning nanofibers as support layer can alleviate internal concentration polarization (ICP). While the macropores of the nanofiber support layer cause defects in the polyamide (PA) layer. Therefore, hydrophobic polyvinylidene fluoride (PVDF) fine nanofibers were used as an interlayer to modulate the process of interfacial polymerization (IP) in this study. The results showed that the introduction of the interlayer improved the hydrophobicity of the support layer for achieving uniform, thin and defect-free selective polyamide (PA) layer. The water flux of TFC-PVDF was 58.26 LMH in the FO mode of 2 M NaCl, which was two times higher than that of the unmodified FO membrane. Lower reverse salt flux (4.91 gMH) and structural parameter (179.43 μm) alleviated the ICP. In addition, TFC-PVDF membrane showed good anti-fouling performance for SA (flux recovery ratio of 93.97%) due to high hydrophilicity, low zeta potential and low roughness. This study provides an easy and promising method to prepare defect-free PA selective layer on the macropores nanofiber support layer. The novel FO membrane shows high desalination performance and anti-fouling properties.

Redox-sensitive self-assembled micelles based on low molecular weight chitosan-lipoic acid conjugates for the delivery of doxorubicin: Effect of substitution degree of lipoic acid

Amphiphilic low molecular weight chitosan-lipoic acid (LC-LA) conjugates with different degrees of substitution (DS) of LA were synthesized by N, N′‑carbonyldiimidazole (CDI) catalysis to self-assemble into redox-sensitive micelles. Critical micelle concentration (CMC), size, zeta potential, biocompatibility and redox-sensitive behavior of blank micelles were investigated. The results indicated that blank micelles with low CMC, nanoscale size and positive zeta potential showed excellent biocompatibility and redox-sensitive behavior. Doxorubicin (Dox) loaded micelles were prepared by encapsulating Dox into blank micelles. The loading ability, trigger-release behavior, antitumor activity and cellular uptake of Dox loaded micelles were studied. The results demonstrated that Dox loaded micelles with superior loading ability exhibited redox-trigger behavior, strong antitumor activity and increased cellular uptake efficiency against A549 cell. Besides, the effect of DS of LA on above properties was estimated. An increase in DS of LA reduced the CMC and cumulative release amount of Dox, but improved the loading efficiency, antitumor activity, and cellular uptake of Dox loaded micelles, which resulted from stronger interaction of hydrophobic groups in micelles with the DS of LA increased. Overall, self-assembled LC-LA micelles with good biosecurity and redox-sensitive behavior hold promising application prospects in Dox delivery and improving cancer therapeutic effect of Dox.

Flocculants based on responsive polymers and chitosan for removal of metallic nanoparticles as contaminants of emerging concern present in water

Wastewater containing polluting nanoparticles during purification is an emerging concern that has created the need to develop more efficient methodologies of wastewater treatment. Therefore, this contribution provides a study regarding the removal of gold and silver nanoparticles stabilized with poly(vinylpyrrolidone) (AuNP-PVP and AgNP-PVP) using flocculation at concentrations of 1.5 and 7.5–8 mg/L in kaolin aqueous dispersions. With this goal in mind, chitosan was grafted with poly(N-vinylcaprolactam)(PNVCL) and poly(acrylic acid)(PAAc) (CS-g-PNVCL, CS-g-PNVCL-PAAc), which was verified by characterization using NMR-spectroscopy, thermogravimetric analysis, dynamic light scattering, and zeta potential measurements. At pH 7, the graft copolymers presented a lower zeta potential than chitosan (close to zero), and the PVP-stabilized nanoparticles exhibited a negative surface charge (around −20 mV). The bridging mechanism during the flocculation process was discovered to be responsible for improving the performance of chitosan using chitosan-based graft polymers with low concentration (0.5 mg/L). CS-g-PNVCL-PAAc allowed higher turbidity reduction (82%), while CS-g-PNVCL was the best flocculant in nanoparticle removal (94% from 7.5 mg/L), at room temperature. The flocculants showed higher ability towards the removal of AgNP-PVP, as compared to AuNP-PVP. By increasing the temperature to 45 °C, the turbidity removal increased, while the nanoparticle removal only improved when the CS-g-PNVCL-PAAc flocculant was used. The effectiveness of chitosan-based flocculants for the removal of metallic nanoparticles as emerging contaminants is reported for the first time. Besides, the removal efficiency of metallic nanoparticles by flocculation is superior as compared to adsorption methods.

Rivaroxaban-loaded SLNs with treatment potential of deep vein thrombosis: in-vitro, in-vivo, and toxicity evaluation

Objectives Rivaroxaban (RXB), a novel Xa inhibitor having groundbreaking therapeutic potential. However, this drug is associated with few limitations, including its pharmacokinetics related toxicities. Here, we developed RXB-loaded SLNs (RXB-SLNs) to improve its biopharmaceutical profile. Methods: High pressure homogenizer was used to prepare RXB-SLNs, followed by their particle characterization, Transmission electron microscopy (TEM), Dynamic light scattering (DSC), and Powder X-ray diffraction (PXRD) analysis. Beside this, in-vitro, ex-vivo, and in-vivo evaluation, prothrombin time assessment and toxicity was investigated. Results RXB-SLNs had their particle size in nano range (99.1 ± 5.50 nm) with excellent morphology and low polydispersity index (0.402 ± 0.02) and suitable zeta potential (−25.9 ± 1.4 mV). The incorporation efficiency was observed around 95.9 ± 3.9%. In-vitro release profiles of the RXB-SLNs exhibited enhanced dissolution (89 ± 9.91%) as compared to pure drug (11 ± 1.43%) after 24 h of the study. PK study demonstrated a seven times enhanced bioavailability of RXB-SLNs when compared with pure drug. Furthermore, RXB-SLNs exhibited an expressive anti-coagulant behavior in human and rat blood plasma. Also, the final formulation exhibited no toxicity after oral administration of the SLNs. Conclusions All together, these studies revealed the capability of the SLNs for carrying the RXB with enhanced therapeutic efficacy and no toxicity, most importantly for the treatment of deep vein thrombosis.

Enzymatically produced nanocellulose as emulsifier for Pickering emulsion

With the increasing demand for label-friendly emulsion products, chemical treatments and the addition of non-natural ingredients are inadvisable in food, cosmetic, and pharmaceutical sectors. The current research proposed a green development strategy from nanocellulose production to emulsion preparation, i.e., enzymatically prepared nanocellulose (ENC) for stabilizing O/W Pickering emulsions. Benefiting from a mild enzymatic reaction, ENC inherently had low Zeta potential and oil/water interfacial tension, facilitating the formation of stable Pickering emulsions. Biphasic fluorescence staining, emulsion polymerization, and rheology were employed to investigate the emulsification characteristics of ENC, establishing the interfacial adsorption behavior and concentration-dependent phase behavior of ENC-stabilized Pickering emulsions. Importantly, due to strong particle-particle and interface-particle interactions dominated by van der Waals forces and hydrogen bonding, ENC-stabilized Pickering emulsions exhibited excellent stability under different temperatures, pH values, NaCl concentrations, and centrifugation. This work provides a green pathway for the development of nanocellulose-based Pickering emulsions.

Synthesis of non-ionic surfactants nano-vesicles for clarithromycin oral delivery

Abstract In order to improve the solubility and bioavailability of poorly water-soluble drugs, the synthesis of cost-effective nonionic surfactants has been the subject of greater scientific interest. The present study focuses on the synthesis of sulfonyl chloride derivatives as nonionic surfactants (surfactant 1 and surfactant 2) and their evaluation for the preparation of a clarithromycin-loaded niosomal drug delivery system. Surfactants 1 and 2 were characterised by EI-MS and 1H NMR spectroscopy. The shape and size of the drug-loaded niosomal vesicles from the synthesised surfactants were examined by atomic force microscopy (AFM) and revealed a round morphology with an average size of (230.8 ± 2.35) nm and (248.1 ± 2.54) nm for the vesicles of surfactant 1 and surfactant 2, respectively. The zeta potential of surfactant 1-based niosomal vesicles was (– 7.70 ± 1.00) mV and that of surfactant 2 was (−14.6 ± 1.08) mV. The lower zeta potential values for surfactant 1 and surfactant 2-based niosomal vesicles showed that these vesicles were neutral and relatively stable. The vesicles of surfactant 1 and 2 have a capacity to entrap the drug of about (62 ± 2.26) % and (69.67 ± 3.23) %, respectively. The vesicles of surfactant 1 released the largest amount of drug, i.e. (70.00 ± 2.45) % at pH 1.2. Biocompatibility in human blood and toxic effects on various cell lines were also studied for surfactants 1 and 2, and they were found to be biocompatible and non-cytotoxic.

Novel microemulsions formulated from sodium N-Lauroyl sarcosinate as nanocarrier for encapsulation of α-Tocopherol

Oil-in-water (o/w) microemulsions (MEs) are gaining increasing attention as nanocarriers for the encapsulation and delivery of hydrophobic bioactive molecules which has huge applications in cosmetic, pharmacological, food and beverage industries. However, the major challenge is to formulate these MEs from biodegradable and biocompatible components in low concentration to form stable formulations. In the current work, physiochemical characterization of blank and α-tocopherol loaded o/w MEs formulated using the biodegradable amino-acid based sodium N-lauroyl sarcosinate (SNLS) as surfactant was performed. These MEs were utilized as potential nanocarriers to solubilize and encapsulate an antioxidant α-tocopherol. The utilization of o/w MEs increased the solubility of α-tocopherol from 0.1% in 10% SNLS solution to 0.2% and 0.8% in MEs without and with cosurfactant respectively. The effect of cosurfactant, concentration of Smix (SNLS:butanol = 1:1) and oil was evaluated using conductivity, viscosity studies and encapsulation efficiency to select the optimum composition for encapsulation. The Z-average size of blank MEs without and with cosurfactant was 304 nm and 199 nm respectively with low PDI and negative zeta potential values determine the enhanced stability of these MEs. The HRTEM images revealed the spherical shape of o/w MEs with darker oily core and were utilized to study the effect of cosurfactant and encapsulation of α-tocopherol on the size and morphology of o/w ME droplets. Further, FTIR studies showed the molecular interactions in α-tocopherol and in the optimized ME. In addition to this, the in-vitro antioxidant study of α-tocopherol loaded MEs was determined by the DPPH free radical scavenging activity and the IC50 value was 9 mg/mL for the optimized ME containing 0.5% α-tocopherol. The contact angle studies revealed excellent wetting and spreading ability of MEs on the hydrophobic surface. Thus, SNLS based o/w MEs could be utilized as potential nanocarriers for the encapsulation and delivery of α-tocopherol.

Dynamic light scattering analysis of immune complexes in sera of rheumatoid arthritis patients

The size of circulating immune complexes (CICs) in rheumatoid arthritis (RA) could be an emerging criterion in disease diagnosis. This study analyzed size and electrokinetic potential of CICs from RA patients, healthy young adults, and RA patients age-matched controls aiming to establish their unique CIC features. Pooled CIC of 30 RA patients, 30 young adults, and 30 RA group's age-matched controls (middle-aged and oldеr healthy adults), and in vitro IgG aggregates from pooled sera of 300 healthy volunteers were tested using dynamic light scattering (DLS). Size distribution of CIC in healthy young adults exhibited high polydispersity. RA CIC patients and their age-matched control showed distinctly narrower size distributions compared with young adults. In these groups, particles clustered around two well-defined peaks. Particles of peak 1 were 36.1 ± 6.8 nm in RA age-matched control, and 30.8 ± 4.2 nm in RA patients. Particles of peak 2 of the RA age-matched control's CIC was 251.7 ± 41.2 nm, while RA CIC contained larger particles (359.9 ± 50.5 nm). The lower zeta potential of RA CIC, compared to control, indicated a disease-related decrease in colloidal stability. DLS identified RA-specific, but also age-specific distribution of CIC size and opened possibility of becoming a method for CIC size analysis in IC-mediated diseases.

Low extracellular vesicle concentrations predict survival in patients with heart failure.

Heart disease is of worldwide importance due to high morbidity and mortality. Extracellular vesicle (EV) concentration and size represent novel diagnostic and prognostic biomarkers, e.g. in patients with liver cancer, but data on their prognostic relevance in heart disease are lacking. Here, we investigated the role of EV concentration, size and zeta potential in patients with heart disease. Vesicle size distribution, concentration and zeta potential were measured by nanoparticle tracking analysis (NTA) in 28 intensive care unit (ICU) and 20 standard care (SC) patients and 20 healthy controls. Patients with any disease had a lower zeta potential compared to the healthy controls. Vesicle size (X50) was significantly higher in ICU patients (245 nm) with heart disease as compared to those patients with heart disease receiving standard care (195 nm), or healthy controls (215 nm) (p = 0.001). Notably, EV concentration was lower in ICU patients with heart disease (4.68 × 1010 particles/ml) compared to SC patients with heart disease (7,62 × 1010 particles/ml) and healthy controls (1.50 × 1011 particles/ml) (p = 0.002). Extracellular vesicle concentration is prognostic for overall survival in patients with heart disease. Overall survival is significantly reduced when the vesicle concentration is below 5.55 × 1010 particles/ml. Median overall survival was only 140 days in patients with vesicle concentrations below 5.55 × 1010 particles/ml compared to 211 days in patients with vesicle concentrations above 5.55 × 1010 particles/ml (p = 0.032). Concentration of EVs is a novel prognostic marker in ICU and SC patients with heart disease.