Terpenoid Hydrazones as Biomembrane Penetration Enhancers: FT-IR Spectroscopy and Fluorescence Probe Studies

Hydrazones based on mono- and bicyclic terpenoids (verbenone, menthone and carvone) have been investigated in vitro as potential biomembrane penetration enhancers. In this regard, liposomes composed of lecithin or cardiolipin as phospholipid phase components with incorporated fluorescence probes have been prepared using the thin-film ultrasonic dispersion method. The mean particle size of the obtained liposomes, established using laser diffraction, was found to be 583 ± 0.95 nm, allowing us to categorize them as multilamellar vesicles (MLVs) according to their morphology. Pursuant to fluorescence analysis, we may assume a reduction in microviscosity and, consequently, a decrease in the packing density of lecithin and cardiolipin lipids to be the major mechanism of action for terpenoid hydrazones 1–15. In order to determine the molecular organization of the lipid matrix, lipids were isolated from rat strata cornea (SCs) and their interaction with tested compounds was studied by means of Fourier transform infrared spectroscopy. FT-IR examination suggested that these hydrazones fluidized the SC lipids via the disruption of the hydrogen-bonded network formed by polar groups of SC constituents. The relationship between the structure of terpenoid hydrazones and their ability to enhance biomembrane penetration is discussed.

Fabrication and evaluation of slow-release lignin-based avermectin nano-delivery system with UV-shielding property

Nanopesticide is one of the best pesticide formulation technologies to overcome the disadvantages of traditional pesticides, which has received great attention from the international community. Using high-speed emulsification and ultrasonic dispersion technology, an avermectin nano-delivery system (Av-NDs) with a particle size of 80–150 nm was prepared through embedding the pesticide molecule utilizing the cross-linking reaction between sodium lignosulfonate and p-phenylenediamine diazonium salt. The formulation and composition of Av-NDs were optimized, the morphology of Av-NDs was analyzed by scanning electron microscope, transmission electron microscope and dynamic light scattering, and the structure of Av-NDs was characterized by UV, IR and 1H NMR. Anti-photolysis and controlled-release tests show that the stability of Av-NDs is 3–4 times of the original avermectin (Av) and possesses the pH-responsive controlled release property. Furthermore, the insecticidal activity of Av-NDs is better than that of avermectin suspension concentrate (Av-SC). The Av-NDs with anti-photolysis and controlled-release characteristics is suitable for large-scale industrial production and is capable to be utilized as effective insecticide in the field.

Study of the properties of MgO/Poly methyl methacrylate Nano-composites

Nanotechnology applications have recently developed in the field of smart sensors that convert energy from one form to another. Nanotechnology is one important source to renewable energy applications, such as the use of solar energy to generate electrical energy A concentration of 0.2 w/v of poly methyl meta acrylic dissolved in dimethylformamide was prepared using hot plate magnetic stirrer magnetic with a temperature up to 50 ° C, and the mixing continued for an hour. 0.02 Percentage of magnesium oxide nanoparticles was added to (poly methyl methacrylate/dimethylformamide) solution and dispersed by ultrasonic dispersion device. The samples were cast into glass containers to obtain thin films with 0.02 mm diameter after drying for 24 hours. Infrared assays were conducted to study the interactions between the polymer and the nanoparticles via studying the nature of the bonds. The differential scanning calorimetry test was performed to measure the thermal properties of the samples. Atomic force microscopy was used to study the surface properties of the samples. The energy gap of samples was calculated. The results proved that the interaction between polymer and nanoparticles is physical interaction. The differential thermal calorimeter results also showed that the adding of MgO nanoparticles leads to increase the glass transition temperature by a small value from (80 °C) to (82 °C). On the other hand, the softening point decreases from (132 ° C) to (120 ° C) and melting point decreases from (173 ° C) to (135 ° C) after adding nanoparticles. As for the results of atomic force microscopy, it was proved that the surface roughness decreases from (2.08 nm) to (1.7 nm) after adding nanoparticles, while the bearing index increases from (0.369) to (0.582). Also, the results of the energy gap proved that the addition of nanoparticles leads to decrease in the energy gap from (4.3 – 4.1) eV, which leads to increase in electrical sensitivity.

Characterization of size and morphological composition of ablated nanoparticles of cerium dioxide after ultrasonic dispersion and centrifugation in aqueous solution

The paper investigates the size and morphological composition of ablated cerium dioxide nanoparticles after ultrasonic dispersion at centrifugation speeds from 800 to 13400 rpm. A nanodispersed solution of cerium dioxide was deposited onto silicon substrates by the drop method. To characterize the size and morphological composition of cerium dioxide nanoparticles, methods of scanning electron and atomic microscopy were used, and X-ray phase analysis was performed. It was found that ablated cerium dioxide particles in an aqueous solution agglomerated and without centrifugation their average size was 162 nm, after centrifugation their average size varied from 86 nm to 142.5 nm. X-ray phase analysis showed that with an increase in the centrifuge speed, the size of the coherent scattering region decreases, which affects the effectiveness of antioxidant properties, for example, in the Fenton reaction.

A Simple Approach to Isolate Slow and Fast Cycling Organic Carbon Fractions in Central European Soils—Importance of Dispersion Method

Numerous approaches have been developed to isolate fast and slow cycling soil organic carbon (SOC) pools using physical and chemical fractionation. Most of these methods are complex, expensive, and time consuming and unsuited for high-throughput application, such as for regional scale assessments. For simpler and faster fractionation via particle size the key issue is the dispersion of soil. It is unclear how the initial dispersion of soil affects the turnover rates of isolated fractions. We investigated five commonly used dispersion methods using different intensities: shaking in water, shaking in water with glass beads, ultrasonication at 100 and 450 J ml−1 and sodium hexametaphosphate (Na-HMP). We used soils from long-term field experiments that included a change from C3 to C4 vegetation and adjacent control sites using δ13C isotope ratio mass spectrometry. We evaluated the degree of C3/C4 moieties of the fractions, mass and carbon recovery and reproducibility as well as the time expenditures of the dispersions, sieving and drying techniques to develop an efficient and cheap fractionation method. Our results indicate that ultrasonication as well as H2O treatment with and without glass beads resulted in fractions with different turnover. Moreover, isolation performances depended on soil texture. While the isolation of the fractions using water with and without glass beads was equivalent to ultrasonication in soils with low clay contents, these methods had limited potential for soils with high clay contents. Furthermore, treatment with water alone had less reproducible results than other tested methods. The SOC recovery was comparable and satisfactory amongst non-chemical dispersion methods and reached over 95% for each of these methods. The use of Na-HMP was unsuccessful due to high time expenditures and strong SOC leaching. We propose particle size fractionation combined with ultrasonic dispersion as a fast and highly reliable method to quantify slow and fast cycling SOC pools for a wide range of soil types and textures from agricultural sites in central Europe.

Obtaining a nanosized silica-humic preparation and its initial approbation

The recent decades have witnessed a significant development and implementation of nanotechnology, including in various branches of agriculture. There is an active search for ways to obtain preparations for plant growing with nanoparticles that can be more rapidly involved in the metabolic processes of plants. This article aims to obtain a nanosized silica-humic preparation and its approbation on potato plants. As a source of humic substances, a liquid humic preparation BoGum (developed by the All-Russian Research Institute of Reclaimed Lands) was used, as a source of silicon – sodium metasilicate. Ultrasonic dispersion method was used for achieving the nanoscale of the samples. A silicon source was introduced in an amount of 0.1% (of SiO2) into BoGum, followed by the application of ultrasonic action for 5, 10, 15 and 20 minutes. The analysis of the obtained samples using a 90 Plus/MAS particle size analyzer has shown that with increasing dispersion time, the effective particle diameter changed insignificantly. At the same time, a redistribution of particles was noted: when the samples were exposed for 20 minutes, the number of smaller particles increased. After 5 minutes of treatment, the range of particle distribution was 115±13–830±23 nm, after 20 minutes of exposure, the particle diameter fell into two regions: 81±8–120±10 and 280±4–470±18 nm. Ultrasonic action contributed to the retention of the stable state of aggregation of the obtained preparation, larger microbiological activity and larger content of humic acid in comparison with the silica-humic preparation, obtained without the application of an ultrasound. The new nanosized silica-humic preparation has been tested on potato plants. Treatment of tubers before planting, followed by foliar spraying of vegetative plants, has contributed to an increase in potato yield by 18.7%. Changes were noted in the content of mono- and polysilicic acids in the soil, as well as the accumulation of silicon in the tops of potatoes when using silicahumic preparations by 0.96% of absolute dry mass on average.

Study of Electrokinetic Properties of Magnetite – Silica Core – Shell Nanoparticles

In this work, the electrokinetic properties of Fe3O4 nanoparticles modified with various alkoxysilanes (tetraethoxysilane and 3-aminopropyltriethoxysilane) in various media were investigated. The determined values of the zeta potential of the Fe3O4/SiO2 samples indicate the complete coverage of nanoparticles with a tetraethoxysilane shell, as well as in the case of the Fe3O4/aminopropyltriethoxysilane. The data obtained on the zeta-potentials of modified nanoparticles with various ligands make it possible to predict the efficiency of subsequent functionalization by target molecules. A decisive role in the study of surface properties is played by cleaning from low molecular weight impurities that can screen the surface of nanoparticles or bind with an indifferent electrolyte. Thus, dispersion on a magnetic stirrer leads to an increase in the sorption capacity of the sample in comparison with ultrasonic dispersion, which causes irreversible destruction of the core-shell nanoparticle structure due to an increase in temperature and pressure in the cavities. This opens the prospective for practical application of modified nanoparticles for creation of tailored composite materials.

Synthesis and Structure of Nanocomposites based on Linear Polymers and Nanoparticles of Titanium Dioxide

Nanocomposites based on titanium dioxide and epoxy polymer nanoparticles have been obtained and investigated by the in situ method at the stage of curing with preliminary ultrasonic dispersion and evacuation. The composition and structure of the obtained TiO2 nanocomposites have been studied by IR spectroscopy and scanning electron microscopy. It is shown that with an increase in the content of nanoparticles, their average size increases to 88 nm at a TiO2 concentration of 1% as a result of secondary aggregation processes