scholarly journals Formation and Stability of Pea Proteins Nanoparticles Using Ethanol-Induced Desolvation

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 949 ◽  
Author(s):  
Chi Diem Doan ◽  
Supratim Ghosh
Keyword(s):  
Aqueous Dispersion ◽  
Spherical Shape ◽  
Random Coil ◽  
Protein Solutions ◽  
Uniform Size ◽  
Pea Protein ◽  
Particle Stability ◽  
Protein Nanoparticles ◽  
Different Temperatures ◽  
Water Ph

Protein nanoparticles have recently found a lot of interests due to their unique physicochemical properties and structure-functionality compared to the conventional proteins. The aim of this research was to synthesize pea protein nanoparticles (PPN) using ethanol-induced desolvation, to determine the changes in secondary structures and the particle stability in an aqueous dispersion. The nanoparticles were prepared by diluting 3.0 wt% pea protein solutions in 1–5 times ethanol at pH 3 and 10 at different temperatures. Higher ratios of ethanol caused greater extent of desolvation and larger sizes of PPN. After homogenization at 5000 psi for 5 min, PPN displayed uniform size distribution with a smaller size and higher zeta potential at pH 10 compared to pH 3. PPN prepared from a preliminary thermal treatment at 95 °C revealed a smaller size than those synthesized at 25 °C. Electron microscopy showed roughly spherical shape and extensively aggregated state of the nanoparticles. Addition of ethanol caused a reduction in β-sheets and an increase in α-helices and random coil structures of the proteins. When PPN were separated from ethanol and re-dispersed in deionized water (pH 7), they were stable over four weeks, although some solubilization of proteins leading to a loss in particle size was observed.

scholarly journals Biosynthesis of CeO2 Nanoparticles Using Egg White and Their Antibacterial and Antibiofilm Properties on Clinical Isolates

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 584
Author(s):  
Shalendra Kumar ◽  
Faheem Ahmed ◽  
Nagih M. Shaalan ◽  
Osama Saber
Keyword(s):  
Bacterial Infections ◽  
Antibacterial Properties ◽  
Spherical Shape ◽  
Inhibition Zone ◽  
Egg White ◽  
Ceo2 Nanoparticles ◽  
Inorganic Materials ◽  
Ambient Conditions ◽  
Uniform Size ◽  
Tem Analysis

Bio-inspired synthesis is a novel and attractive environmentally friendly route to generating inorganic materials. In this work, the preparation of CeO2 NPs using egg white and investigation of their antibacterial properties both in liquid and solid growth medium against Escherichia coli and Staphylococcus aureus bacteria were reported. The CeO2 nanoparticles were characterized using X-ray diffraction (XRD), Field emission transmission electron microscope (FETEM), UV-Vis, Raman, and antibacterial measurements. The results from XRD and TEM analysis showed that the prepared nanoparticles were a single phase in the nano regime (5–7 nm) with spherical shape and uniform size distribution. Optical properties reflected the characteristics peaks of CeO2 in the UV-Vis range with a bandgap ~2.80 eV. The antibacterial activity of the synthesized NPs was achieved under ambient conditions with different bacteria and the results showed that the properties were different for both the bacteria. The highest activity with an inhibition zone of about 22 mm against S. aureus was obtained as compared with the 19 mm zone of inhibition obtained with E.coli. This finding will be of major significance that indicates a possibility to develop CeO2 NPs as antibacterial agents against extensive microorganisms to control and prevent the spread and persistence of bacterial infections.

In situstudy of the kinetics of growth of Pb nanoparticles embedded in a PbO–B2O3glass

2018 ◽  
Vol 51 (2) ◽  
pp. 395-405
Author(s):  
Andreia Gorgeski ◽  
Aldo Felix Craievich ◽  
Leonardo Marcon Corrêa ◽  
Luciano Andrei Montoro ◽  
Guinther Kellermann
Keyword(s):  
Isothermal Annealing ◽  
Equilibrium Concentration ◽  
Spherical Shape ◽  
Distribution Functions ◽  
Relative Dispersion ◽  
Droplet Growth ◽  
Temperature Dependences ◽  
Different Temperatures ◽  
Size Dispersion

The process of growth of liquid Pb nanoparticles embedded in a lead borate glass was investigated by transmission electron microscopy (TEM) and byin situsmall-angle X-ray scattering (SAXS) during isothermal annealing at different temperatures within the 649–679 K range. A TEM study at room temperature of the glass–Pb nanoparticle composite, previously subjected to isothermal annealing, showed the presence of a number of nearly spherical Pb nanocrystals with some size dispersion. The analysis of several series of experimental SAXS curves recordedin situ, for increasing periods of time of isothermal annealing at different temperatures, allowed the authors to determine time and temperature dependences of the radius distribution functions of the growing spherical Pb nanoparticles. Since all selected annealing temperatures were higher than the melting temperature of bulk Pb, the Pb nanoparticles were in all cases in the liquid state during the whole growth process. A fast increase in the total volume of Pb droplets was observed during the initial stages of annealing, which indicated that the Pb droplets grow because of the incorporation of Pb atoms dispersed in the glass matrix. For more advanced stages of droplet growth, when the concentration of Pb atoms becomes close to its equilibrium concentration, the time dependences of the average radius, number density and total volume of Pb droplets are those predicted by the classical theory of coarsening proposed by Lifshitz–Slyosov–Wagner. Furthermore, it has been established that the Pb nanodroplets preserve their spherical shape and their relative dispersion in size through the whole coarsening process and that the activation energy for diffusion of Pb atoms and growth of Pb droplets embedded in the studied glass isEa= 2.65 ± 0.09 eV per atom.

Control of Morphology of YBO3:Eu by a Mild Hydrothermal Process

2005 ◽  
Vol 475-479 ◽  
pp. 1829-1832
Author(s):  
Ling He ◽  
Yu Hua Wang
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Single Phase ◽  
Hydrothermal Process ◽  
Spherical Shape ◽  
Solid State Reactions ◽  
Main Peak ◽  
Photoluminescence Intensity ◽  
Uniform Size ◽  
Excitation Peak

The phosphors YBO3:Eu with different morphology was successfully realized by mild hydrothermal process with different reaction condition. Highly spherical shape, uniform size and non-agglomeration of YBO3:Eu phosphors particle was obtained at 260°C,which is about 850°C lower than that by solid state reactions. The result of XRD showed that all samples were single phase with vaterite type structure. From IR and NMR spectra, it could be concluded that YBO3 contains mainly BO4 tetrahedra which is in favor for absorption VUV excitation. Monitoring by 598nm emission, the main excitation peak at about 247nm was observed in the excitation spectrum of spherical Y0.95Eu0.05BO3. Correspondingly, under 247nm excitation, the main peak at about 598nm was observed. The photoluminescence intensity (5D0→7F1 transition of Eu3+) of spherical shape of Y0.95Eu0.05BO3 was 1.5 times in comparison with which prepared by solid-state reactions. The best photoluminescence intensity was obtained when the concentration of Eu3+ is at 20 at. %. It indicated that hydrothermal method have a potential in the preparing various particles phosphors for application in displays and lamps.

Synthesis and Characterization of Crystalline FeCo Nanoparticles

2006 ◽  
Vol 6 (11) ◽  
pp. 3417-3421 ◽  
Author(s):  
Chang Woo Kim ◽  
Young Hwan Kim ◽  
Hyun Gil Cha ◽  
Don Keun Lee ◽  
Young Soo Kang
Keyword(s):  
Exchange Coupling ◽  
Chemical Method ◽  
Coupling Effect ◽  
Molar Ratio ◽  
Feco Alloy ◽  
Uniform Size ◽  
Different Temperatures ◽  
Shape Controlled ◽  
Feco Nanoparticles

The monodispersed FeCo nanoparticles were synthesized with borohydride as a reducing agent by coprecipitation method in aqueous solution. The composition and the size of FeCo nanoparticle was controlled by fitting the molar ratio of starting material, the reaction time and the falling rate. To prepare the crystallized nanoparticles, the amorphous FeCo nanoparticles were annealed at the different temperatures for 1 hr, respectively. The size of the crystalline FeCo nanoparticles was controlled in order to maintain the uniform size of 20nm. The as-annealed FeCo alloy could get the highest Ms value of the powder which has been ever synthesized by coprecipitation or other chemical method. The size- and shape-controlled crystalline FeCo nanoparticles can be applied for spring magnet in order to get exchange coupling effect.

scholarly journals Cell-Penetrating Peptide and Transferrin Co-Modified Liposomes for Targeted Therapy of Glioma

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3540 ◽  
Author(s):  
Xi Wang ◽  
Yarong Zhao ◽  
Shiyan Dong ◽  
Robert J. Lee ◽  
Dongsheng Yang ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Therapeutic Agent ◽  
Spherical Shape ◽  
Cell Penetrating Peptides ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Great Promise ◽  
Uniform Size ◽  
Cell Penetrating ◽  
Low Toxicity

Glioma is one of the most aggressive and common malignant brain tumors. Due to the presence of the blood-brain barrier (BBB), the effectiveness of therapeutics is greatly affected. In this work, to develop an efficient anti-glioma drug with targeting and which was able to cross the BBB, cell-penetrating peptides (R8) and transferrin co-modified doxorubicin (DOX)-loaded liposomes (Tf-LPs) were prepared. Tf-LPs possessed a spherical shape and uniform size with 128.64 nm and their ξ-potential was 6.81 mV. Tf-LPs were found to be stable in serum within 48 h. Uptake of Tf-LPs in both U87 and GL261 cells was analyzed by confocal laser scanning microscopy and by flow cytometry. Tf-LPs were efficiently taken up by both U87 and GL261 cells. Moreover, Tf-LPs exhibited sustained-release. The cumulative release of DOX from Tf-LPs reached ~50.0% and showed excellent anti-glioma efficacy. Histology of major organs, including brain, heart, liver, spleen, lungs and kidney, and the bodyweight of mice, all indicated low toxicity of Tf-LPs. In conclusion, Tf-LPs showed great promise as an anti-glioma therapeutic agent.

Preparation and Particle Size Characterization of Cu Nanoparticles Prepared by Anodic Arc Plasma

2010 ◽  
Vol 92 ◽  
pp. 163-169
Author(s):  
Hong Xia Qiao ◽  
Zhi Qiang Wei ◽  
Ming Ru Zhou ◽  
Zhong Mao He
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Uniform Size

Copper nanoparticles were successfully prepared in large scales by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), BET equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experiment results indicate that the crystal structure of the samples is fcc structure as same as that of the bulk materials. The specific surface area is is 11 m2/g, with the particle size distribution ranging from 30 to 90 nm, the average particle size about 67nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles have uniform size, higher purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.

Monodispersed Magnetic Fluids: Synthesis and Characterization

2009 ◽  
Vol 155 ◽  
pp. 155-162 ◽  
Author(s):  
Kinnari Parekh ◽  
R.V. Upadhyay ◽  
V.K. Aswal
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Single Phase ◽  
Magnetic Measurement ◽  
Spherical Shape ◽  
Uniform Size ◽  
Xrd Pattern ◽  
X Ray ◽  
Monodispersed Particles ◽  
Phase Spinel

Magnetite and Co ferrite particles were synthesized with control of particle size distribution via non-aqueous route. The XRD pattern shows the formation of single phase spinel structure with the particle size of 96 Å and 80 Å respectively for magnetite and cobalt ferrite. TEM image of the same shows the particles are nearly spherical with the size matches with that obtained from X-ray and the size distribution is less than 5%. Magnetic measurement also shows the particles of uniform size with high value of saturation magnetization at room temperature compared to that obtained by other route. SANS study confirms our results of monodispersed particles with spherical shape.

Preparing Monodisperse Metal Powders in Micrometer and Submicrometer Sizes by the Polyol Process

MRS Bulletin ◽  
1989 ◽  
Vol 14 (12) ◽  
pp. 29-34 ◽  
Author(s):  
F. Fievet ◽  
J.P. Lagier ◽  
M. Figlarz
Keyword(s):  
Thick Film ◽  
Materials Science ◽  
Precious Metals ◽  
Spherical Shape ◽  
Particle Growth ◽  
Metal Particles ◽  
Metal Powders ◽  
Uniform Size ◽  
Conductive Inks ◽  
Gold Colloids

One of the newer tendencies in materials science has been to tailor-make classical products (long associated with old applications) with controlled properties for special uses, especially in high technology. Preparing dispersed systems in which all particles have nearly uniform size (monodisperse solids) is a typical example. This goal can be achieved in some cases through cleverly controlled particle growth from a liquid medium. Examples of such preparations include gold colloids prepared by Zsigmondy and later by Turkevich et al., sulfur sols obtained by LaMer, metal oxides and hydrous oxides prepared by Matijević et al., silica, etc. These dispersions have been used either to check theories of colloid science, or to a lesser extent, for industrial purposes. In the case of fine metal particles, a uniform size distribution associated with a low degree of agglomeration, and sometimes the spherical shape, appear as particularly convenient characteristics for certain applications. The production of conductive inks or pastes for electronic materials and for the preparation of conductive paints are particularly good examples.In so-called thick film technology, conductive inks and pastes are screen printed on a ceramic substrate in order to form, after firing, a conductive film with a thickness less than 10 μm. This technique is, for instance, used to form the network in hybrid integrated circuits or the internal electrodes of multilayer ceramic capacitors.Metallic powders in thick film compositions are usually precious metals (Au, Ag, Pt, Pd), their mixtures, or alloys. Cheaper metals such as copper or nickel are tested and may be potential substitutes for precious metals in different specific applications. Powders for thick film composition are mainly obtained through chemical precipitation from aqueous or organic solutions, which yield high purity powders. Modification of precipitation parameters (such as the nature and the concentration of the starting metallic compound and of the reducing agent, reaction temperature, viscosity of the medium) and the addition of additives and surfactants, can often be used to control particle size and agglomeration.Over the past few years, we have developed a new process for preparing finely divided metal powders of easily reducible metals (such as precious metals and copper) or less reducible metals (such as cobalt, nickel, cadmium, or lead) by precipitation in liquid polyols. This reaction will be used as an example in order to discuss the mechanism of formation of uniform micrometer and submicrometer size metal particles by precipitation reactions.

scholarly journals Oxidized Dextran as a Macromolecular Crosslinker Stabilizes the Zein/Caseinate Nanocomplex for the Potential Oral Delivery of Curcumin

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4061 ◽  
Author(s):  
Nikolas J. Rodriguez ◽  
Qiaobin Hu ◽  
Yangchao Luo
Keyword(s):  
Bioactive Compounds ◽  
Oral Delivery ◽  
Colloidal Stability ◽  
Schiff Base Complex ◽  
Spherical Shape ◽  
Heating Time ◽  
Morphological Observation ◽  
Hydrophobic Core ◽  
Uniform Size ◽  
Oxidized Dextran

In this study, we prepared complex nanoparticles from a combination of two proteins and one polysaccharide for the encapsulation and delivery of lipophilic bioactive compounds. Two proteins, zein and sodium caseinate (NaCas), provided a hydrophobic core for the encapsulation of a lipophilic compound (curcumin), while a polysaccharide dialdehyde, oxidized dextran, served as the coating material and macromolecular crosslinker to create covalent linkage with two proteins for stabilization purposes. The heating time and crosslinker concentration were optimized to achieve the desirable colloidal stability in simulated gastric and intestinal fluids. Our results suggested that heating time played a more important role than the concentration of oxidized dextran. The optimized complex nanoparticles had a particle size of around 150 nm with a PDI < 0.1 and negative surface charge. Morphological observation by transmission electron microscopy revealed a spherical shape and uniform size distribution. Fourier transform infrared and fluorescence spectroscopies evidenced the formation of Schiff base complex, confirming the validity of covalent crosslinking. Furthermore, the complex nanoparticles demonstrated superior encapsulation properties for curcumin, showing an efficiency of >90% at 10% loading. A rather slow kinetic release profile of curcumin from complex nanoparticles was observed under simulated gastrointestinal conditions. The complex nanoparticles prepared from zein, NaCas, and oxidized dextran hold promising potential for the oral delivery of lipophilic bioactive compounds.

Plasmid linearization changes shape and efficiency of transfection complexes

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Roman Lehner ◽  
Xueya Wang ◽  
Patrick Hunziker
Keyword(s):  
Electron Microscopy ◽  
Plasmid Dna ◽  
Transfection Efficiency ◽  
Spherical Shape ◽  
Random Coil ◽  
Experimental Conditions ◽  
Delivery Vector ◽  
Transmission Electron ◽  
Key Factor ◽  
Transfection Agent

AbstractThe ability to efficiently transfect plasmid DNA (pDNA) into eukaryotic cells has exerted major impact on scientific research in recent years, and translation to clinical application is ongoing, but challenging. In addition to the choice of the delivery vector, the topology of the DNA seems to be a key factor for efficient transfection. The nanostructured DNA/Vector complexes may differ in size, charge, and shape, for example. This study therefore investigated the transfection efficiency of circular versus linearized plasmid DNA using a GFP expressing vector with Lipofectamine2000 and linear 25 kDA polyethylenimine (PEI). Transfection efficiency and cytotoxicity were measured by flow cytometry and fluorescence microscopy. Shape was determined by transmission electron microscopy. Transfection agent concentrations were chosen below the toxicity level. We determined the optimal N/P ratio over 48 h by using two different concentrations of plasmid DNA. With the increase of DNA concentration and increasing N/P ratio, transfection efficiency also increased. Our results showed a better transfection efficiency with the circular compared to the linearized DNA, under the same experimental conditions for both Lipofectamine and PEI. In electron microscopy, there was a notable difference in the shape of the complexes: circular DNA had random coil appearance in well compacted, roughly spherical shape, while linearized DNA appeared as worm-like strands, both, when complexed with Lipofectamine or with polyethyleneimine. This generates the hypothesis that the shape of the transfection particle may be an important factor for successful gene transfer.

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