Zeta potential changing self-nanoemulsifying drug delivery systems: A newfangled approach for enhancing oral bioavailability of poorly soluble drugs

The mucus is a defensive barrier for different drug-loaded systems. To overcome this obstacle, the crucial factor is the surface charge. Due to mucus negative charge behavior; it was revealed that negatively charged formulations can move across mucus, whereas positively charged nanoformulations could not diffuse via mucus due to interactions. However, cellular intake of negatively charged nanoformulations to the epithelium by endocytosis is less prominent as compared to positively charged carriers. Self-emulsifying drug delivery systems (SEDDS) improve the drug permeability of drugs, especially which have poor oral drug solubility. Moreover, SEDDS have the ability to reduce the degradation of drugs in the GI tract. Currently, drug carrier systems that can shift zeta potential from negative to positive were developed. The benefits of inducing zeta potential changing approach are that negatively charged nanoformulations permeate quickly across the mucus and surface charges reversed to positive at epithelium surface to increase cellular uptake. Among various systems of drug delivery, zeta potential changing SEDDS seem to signify a promising approach as they can promptly diffuse over mucus due to their smaller size and shape distortion ability. Due to such findings, mucus permeation and drug diffusion may improve by the mixture of the zeta potential changing approach and SEDDS.

Solvent-Dependent Photoluminescence Emission and Colloidal Stability of Carbon Quantum dots from Watermelon Peels

Waste peels are considered an environmental burden and typically disposed in landfills. The aim of this study was to investigate the effects of various solvents on the luminescence properties of carbon quantum dots (CQDs). Watermelon peels were recycled and reuse as precursors for the synthesis of biomass CQDs via a green carbonization method. The colloidal stability, surface charge, and particle size were characterized using zeta potential and dynamic light scattering (DLS). DLS revealed that the size of the CQDs was approximately 5.80 ± 0.4 nm to 9.74 ± 0.8 nm. The high-resolution transmission electron microscopy (HRTEM) results demonstrated a correlation with the DLS results. The optical properties were characterized by photoluminescence (PL) and UV-Visible (UV-Vis) spectroscopy. PL measurements at different excitation wavelengths revealed that the CQDs emissions were influenced by the polarity of the solvents. Meanwhile, the Fourier transform infra-red (FTIR) results showed the presence of oxygen-containing groups on the surface of the CQDs. These results deepen our understanding of the solvent-dependent behavior and colloidal stability of the CQDs.

Nanoformulations with exopolysaccharides from cyanobacteria: enhancing the efficacy of bioactive molecules in the Mediterranean fruit fly control

The increasing demand for food has required intensive use of pesticides which are hazardous to the ecosystem. A valid alternative is represented by biopesticides; however, these molecules are often insoluble in water, and poorly bioavailable. Nanopesticides can be engineered to reach a selected target with controlled release of the active principle. In this work, capsaicin, an irritant alkaloid from hot chili peppers, and hydroxytyrosol, a phenolic compound obtained from extra-virgin olive oil by-products, were loaded into innovative nanocarriers. These were designed ad hoc combining exopolysaccharides from the cyanobacteria Neocyanospira capsulata, and a lipid component, i.e., egg phosphatidylcholine. The polysaccharide was chosen for chemical affinity with the chitin of insect exoskeleton, while the lipids were introduced to modulate the carrier rigidity. The newly formed nanosystems were characterized by physico-chemical techniques and tested for their possible use in pest control programs. The Mediterranean Fruit Fly Ceratitis capitata Wiedemann, 1824 (Diptera, Tephriditae), a pest of the Mediterranean Region causing high economic losses, was used as a model insect. We found that the nanoformulations nanocarriers prepared in this work, were able to increase the ovicidal effect of hydroxytyrosol. Moreover, the formulation encapsulating either hydroxytyrosol or capsaicin were able to reduce the number of females landing on treated apricots.

Relationship Between Zeta Potential and Wettability in Porous Media: Insights From a Simple Bundle of Capillary Tubes Model

HYPOTHESIS & MOTIVATION

Experimental data suggest a relationship between the macroscopic zeta potential measured on intact rock samples and the sample wettability. However, there is no pore-scale model to quantify this relationship.

METHODS

We consider the simplest representation of a rock pore space: a bundle of capillary tubes of varying size. Equations describing mass and charge transfer through a single capillary are derived and the macroscopic zeta potential and wettability determined by integrating over capillaries. Model predictions are tested against measured data yielding a good match.

FINDINGS

Mixed- and oil-wet models return a macro-scale zeta potential that is a combination of the micro-scale zeta potential of mineral-brine and oil-brine interfaces and the relationship between macro-scale zeta potential and water saturation exhibits hysteresis. The model predicts a similar relationship between zeta potential and wettability to that observed in experimental data but does not provide a perfect match. Fitting the model to experimental data allows the oil-brine zeta potential to be estimated at conditions where it cannot be measured directly. Results suggest that positive values of the oil-brine zeta potential may be more common than previously thought with implications for surface complexation models and the design of controlled salinity waterflooding of oil reservoirs.

Modification of physico-chemical surface properties and growth of Staphylococcus aureus under hyperglycemia and ketoacidosis conditions

Diabetes is a widely spread disease affecting the quality of life of millions of people around the world and is associated to a higher risk of developing infections in different parts of the body. The reasons why diabetes enhances infection episodes are not entirely clear; in this study our aim was to explore the changes that one of the most frequently pathogenic bacteria undergoes when exposed to hyperglycemia and ketoacidosis conditions. Physical surface properties such as hydrophobicity and surface electrical charge are related to bacterial growth behavior and the ability of Staphylococcus aureus to form biofilms. The addition of glucose made bacteria more negatively charged and with moderate-intermediate hydrophobicity. Ketone bodies increased hydrophobicity to approximately 75% and pathological concentrations hindered some of the bacterial surface charge by decreasing the negative zeta potential of cells. When both components were present, the bacterial physical surface changes were more similar to those observed in ketone bodies, suggesting a preferential adsorption of ketone bodies over glucose because of the more favorable solubility of glucose in water. Glucose diabetic concentrations gave the highest number of bacteria in the stationary phase of growth and provoked an increase in the biofilm slime index of around 400% in relation to the control state. Also, this situation is related with an increase of bacterial coverage. The combination of a high concentration of glucose and ketone bodies, which corresponds to a poorly controlled diabetic situation, appears associated with an early infection phase; increased hydrophobic attractive force and reduced electrostatic repulsion between cells results in better packing of cells within the biofilm and more efficient retention to the host surface. Knowledge of bacterial response in high amount of glucose and ketoacidosis environments can serve as a basis for designing strategies to prevent bacterial adhesion, biofilm formation and, consequently, the development of infections.

Zeta Potential Dependent Self-Assembly for Very Large Area Nanosphere Lithography

Nanosphere lithography offers a rapid, low-cost approach for patterning of large-area two-dimensional periodic nanostructures. However, a complete understanding of the nanosphere self-assembly process is necessary to enable further development and scaling of this technology. The self-assembly of nanospheres into two-dimensional periodic arrays has previously been attributed solely to the Marangoni force; however, we demonstrate that the ζ potential of the nanosphere solution is critically important for successful self-assembly to occur. We discuss and demonstrate how this insight can be used to greatly increase self-assembled 2D periodic array areas while decreasing patterning time and cost. As a representative application, we fabricate antireflection nanostructures on a transparent flexible polymer substrate suitable for use as a large-area (270 cm²), broadband, omnidirectional antireflection film.

Fabrication, Characterization, In vitro Evaluation of Solid Lipid Nanoemulsion of Flunarizine dihydrochloride for Nasal Delivery

BACKGROUND

Flunarizine dihydrochloride (FHC) is used for the prophylaxis to migraine. Flunarizine has solubility problems which is practically insoluble in water and alcohol. Nanoemulsion is the approach to increase the solubility of the insoluble drugs. Nanoemulsions of FHC was prepared which can be given through the alternate route such as nasal drug delivery for migraine.

OBJECTIVE

In this research work the solubility of the poorly soluble FHC was successfully improved by preparing it as a nano emulsion. Nanoemulsions can pass through the biological membrane easily so it can be delivered through nasal mucosa by which it may provide a quicker onset of action. The currently available dosage forms are in the form of tablet.

METHODS

The formulations were prepared by using Glycerl Monostearate (GMS), Tween 80 as surfactant and PEG 400: Ethanol as co-surfactant in the distilled water. Nanoemulsions were prepared by step by step procedure. The prepared nanoemulsions were analyzed preliminarily by Master Sizer followed by Zeta Sizer by using the technique Dynamic Photon Correlation Spectroscopy. The best nanoemulsion was subjected to Zeta Potential study. The TEM analysis was carried out on the best formulation to gain the detailed information about the formulation.

RESULTS

The best formulation was selected based on the physical appearance, homogenecity of the preparation, Preliminary Master Sizer analysis report, Secondary Zeta Sizer analysis report with Zeta Potential and TEM. The best formulation demonstrated the size in nano range with improved solubility.

CONCLUSION

The FHC nano emulsion was prepared successfully which improved the solubility of the drug. The drug release study on simulated nasal fluid revealed that the preparation is suitable to be delivered through the nasal route.

Zeta Sperm Selection Improves Pregnancy Rate and Alters Sex Ratio in Male Factor Infertility Patients: A Double-Blind, Randomized Clinical Trial

Background

Selection of sperm for intra-cytoplasmic sperm injection (ICSI) is usually considered as the ultimate technique to alleviate male-factor infertility. In routine ICSI, selection is based on morphology and viability which does not necessarily preclude the chance injection of DNA-damaged or apoptotic sperm into the oocyte. Sperm with high negative surface electrical charge, named “Zeta potential”, are mature and more likely to have intact chromatin. In addition, X-bearing spermatozoa carry more negative charge. Therefore, we aimed to compare the clinical outcomes of Zeta procedure with routine sperm selection in infertile men candidate for ICSI.

Materials and Methods

From a total of 203 ICSI cycles studied, 101 cycles were allocated to density gradient centrifugation (DGC)/Zeta group and the remaining 102 were included in the DGC group in this prospective study. Clinical outcomes were com- pared between the two groups. The ratios of Xand Y bearing sperm were assessed by fluorescence in situ hybridization (FISH) and quantitative polymerase chain reaction (qPCR) methods in 17 independent semen samples.

Results

In the present double-blind randomized clinical trial, a significant increase in top quality embryos and pregnancy rate were observed in DGC/Zeta group compared to DGC group. Moreover, sex ratio (XY/XX) at birth significantly was lower in the DGC/Zeta group compared to DGC group despite similar ratio of X/Y bearings sper- matozoa following Zeta selection.

Conclusion

Zeta method not only improves the percentage of top embryo quality and pregnancy outcome but also alters the sex ratio compared to the conventional DGC method, despite no significant change in the ratio of Xand Ybearing sperm population (Registration number: IRCT201108047223N1).

Effect of cattle breeds on milk composition and technological characteristics in china

Cattle breeds have a striking effect on milk, including milk composition and technological characteristics. This study aims to compare milk composition, acidification activity, viscosity, milk dispersion system stability and casein molecular weight among three buffalo breeds in China. The technological characteristics of milk produced by three cattle breeds of river buffalo (Murrah), crossbreed 1st generation (F1), crossbreed multiple generation (FH, H≥3) buffaloes were investigated. Cattle breeds showed evident effect on milk protein, fat and total solids content, but little effect on most of buffalo casein molecular weight. Milk fat, protein content and the viscosity of buffalo milk from river buffalo were lower than those of F1 and FH, so was the buffer capacity. The viscosity was negatively correlated to temperature and concentration. Results of stability coefficient showed that milk dispersion system had the best dynamic stability characteristics under pH 6.6 and 6 times dilution, while zeta potential of Murrah milk was slightly higher than that of hybrid offspring (F1, FH). SDS-PAGE results showed that buffalo αs-casein had a slightly faster mobility than standard αs-casein; while buffalo β-casein showed a slightly slower mobility than standard β-casein. There is no clear differences in molecular weight of αs-, β-, and κ-casein among Murrah, F1 and FH.