Formation and Physicochemical Characteristics of Nano Biochar: Insight into Chemical and Colloidal Stability

2018 ◽  
Vol 52 (18) ◽  
pp. 10369-10379 ◽  
Author(s):  
Guocheng Liu ◽  
Hao Zheng ◽  
Zhixiang Jiang ◽  
Jian Zhao ◽  
Zhenyu Wang ◽  
...  
Keyword(s):  
Colloidal Stability ◽  
Physicochemical Characteristics ◽  
Insight Into

scholarly journals The Effect of pH and Viscosity on Magnetophoretic Separation of Iron Oxide Nanoparticles

2021 ◽  
Vol 7 (6) ◽  
pp. 80
Author(s):  
Leonie Wittmann ◽  
Chiara Turrina ◽  
Sebastian P. Schwaminger
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Colloidal Stability ◽  
Downstream Processing ◽  
Physicochemical Characteristics ◽  
Particle Migration ◽  
Aggregation Behavior ◽  
Oxide Nanoparticles ◽  
Separation Processes ◽  
Effect Of Ph

Magnetic nanoparticles (MNPs) are used for magnetophoresis-based separation processes in various biomedical and engineering applications. Essential requirements are the colloidal stability of the MNPs and the ability to be separated even in low magnetic field gradients. Bare iron oxide nanoparticles (BIONs) with a diameter of 9.2 nm are synthesized via coprecipitation, exhibiting a high saturation magnetization of 70.84 Am2 kg−1 and no remanence. In our study, zeta potential, dynamic light scattering (DLS), and sedimentation analysis show that the aggregation behavior of BIONs is influenced by pH and viscosity. Small aggregate clusters are formed with either low or high pH values or increased viscosity. Regarding magnetophoresis-based separation, a higher viscosity leads to lower magnetophoretic velocities, similar to how small aggregates do. Additionally, cooperative magnetophoresis, the joint motion of strongly interacting particles, affects the separation of the BIONs, too. Our study emphasizes the effect of pH and viscosity on the physicochemical characteristics of MNPs, resulting in different aggregation behavior. Particularly, for high viscous working media in downstream processing and medicine, respectively, the viscosity should be taken into account, as it will affect particle migration.

scholarly journals Internalization and Transport of PEGylated Lipid-Based Mixed Micelles across Caco-2 Cells Mediated by Scavenger Receptor B1

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2022
Author(s):  
Xiangjie Su ◽  
Mercedes Ramírez-Escudero ◽  
Feilong Sun ◽  
Joep B. van den Dikkenberg ◽  
Mies J. van Steenbergen ◽  
...  
Keyword(s):  
Vitamin K ◽  
Colloidal Stability ◽  
Mixed Micelles ◽  
Scavenger Receptor ◽  
Facs Analysis ◽  
Pegylated Nanoparticles ◽  
Confocal Fluorescence ◽  
Docking Calculations ◽  
Epithelium Cells ◽  
Insight Into

The aim of this study was to get insight into the internalization and transport of PEGylat-ed mixed micelles loaded by vitamin K, as mediated by Scavenger Receptor B1 (SR-B1) that is abundantly expressed by intestinal epithelium cells as well as by differentiated Caco-2 cells. Inhibition of SR-B1 reduced endocytosis and transport of vitamin-K-loaded 0%, 30% and 50% PEGylated mixed micelles and decreased colocalization of the micelles with SR-B1. Confocal fluorescence microscopy, fluorescence-activated cell sorting (FACS) analysis, and surface plasmon resonance (SPR) were used to study the interaction between the mixed micelles of different compositions (varying vitamin K loading and PEG content) and SR-B1. Interaction of PEGylated micelles was independent of the vitamin K content, indicating that the PEG shell prevented vitamin K exposure at the surface of the micelles and binding with the receptor and that the PEG took over the micelles’ ability to bind to the receptor. Molecular docking calculations corroborated the dual binding of both vita-min K and PEG with the binding domain of SR-B1. In conclusion, the improved colloidal stability of PEGylated mixed micelles did not compromise their cellular uptake and transport due to the affinity of PEG for SR-B1. SR-B1 is able to interact with PEGylated nanoparticles and mediates their subsequent internalization and transport.

scholarly journals Effect of Plant Extracts on the Characteristics of Silver Nanoparticles for Topical Application

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1244
Author(s):  
Ioanna K. Siakavella ◽  
Fotini Lamari ◽  
Dimitrios Papoulis ◽  
Malvina Orkoula ◽  
Patroula Gkolfi ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Colloidal Stability ◽  
Skin Barrier ◽  
Physicochemical Characteristics ◽  
Total Phenolic ◽  
Flavonoid Content ◽  
Laser Scattering ◽  
The Impact ◽  
Phenolic And Flavonoid

Silver nanoparticles (AgNPs) were synthesized using hydroalcoholic extracts of dittany (Origanum dictamnus), sage (Salvia officinalis), sea buckthorn (Elaeagnus rhamnoides, syn. Hippophae rhamnoides), and calendula (Calendula officinalis) as reducing agents. AgNPs synthesized using NaBH4 and citric acid were used as control. The impact of the origin of the extract and preparation conditions (light, temperature, reaction time) on the properties of the synthesized AgNPs was investigated. The structure, morphology, composition, physicochemical characteristics, and colloidal stability were characterized using dynamic laser scattering (DLS), ultraviolet-visible spectrophotometry (UV–/Vis), XRD, X-ray fluorescence (XRF), TEM, and FTΙR. The reduction of total phenolic and flavonoid content of the extracts after the reaction of AgNPs synthesis was also determined. Low IC50 values for all types of AgNPs revealed good antioxidant activity, attributable to the phenolic and flavonoid content of their surface. The results suggest that plant extract selection is important to the green synthesis of AgNPs because it affects the kinetics of their synthesis as well as their morphology, physicochemical characteristics, and colloidal stability. In vitro permeation studies on porcine skin revealed that AgNPs remained at the upper layers of stratum corneum and did not penetrate the skin barrier after 4 h of cutaneous application suggesting the safety of their application on intact skin for a relatively short time.

A New Insight into the Mechanistic Study on Synthesis of Silica Nanospheres

2007 ◽  
Vol 124-126 ◽  
pp. 1249-1252
Author(s):  
Dong Shin Yun ◽  
Hyun Jung Kim ◽  
Hyun Chang Shin ◽  
Venkatathri Narayanan ◽  
Jung Whan Yoo ◽  
...  
Keyword(s):  
Physicochemical Characteristics ◽  
Mechanistic Study ◽  
Partial Hydrolysis ◽  
Particle Sizes ◽  
Species Concentration ◽  
Surface Areas ◽  
Ft Ir ◽  
Alkoxy Groups ◽  
Hydrolysis Of ◽  
Insight Into

The physicochemical characteristics (SEM, N2 adsorption, FT-IR, MASNMR) of samples from kinetics (10 min, 20 min, 30 min, 1 h and 3h) of hydrolysis of tetraethyl orthosilicate (TEOS) gives new insight into the synthesis of nanosphere. The particle sizes are increased with time, however, the surface areas decreased. FT-IR investigation reveals the presence of high intensed silanol groups of 960 cm-1 at 10 min, which reduced on progress of the reaction time. This suggests the partial hydrolysis and condensation of alkoxy groups in TEOS. 29Si MASNMR analysis shows the presence three different silica species(Q4, Q3 and Q2) in 10 and 20 min samples. The intensity of Q2 species decreases with time and other species concentration were increased.

scholarly journals The β-casein-resveratrol complex: Physicochemical characteristics and implications for enhanced nutrition

2016 ◽  
Vol 81 (7) ◽  
pp. 739-750 ◽  
Author(s):  
Hao Cheng ◽  
Li Yanfang ◽  
Xundi Yin ◽  
Muriel Subirade ◽  
Li Liang
Keyword(s):  
Physicochemical Characteristics ◽  
Bioactive Molecules ◽  
Visible Absorption ◽  
Absorption And Fluorescence Spectroscopy ◽  
Natural Polyphenol ◽  
Carrier Materials ◽  
Total Antioxidant ◽  
Carrier Systems ◽  
Molecule Interaction ◽  
Insight Into

Food proteins have been widely used as carrier materials for the encapsulation and protection of bioactive molecules. Clarification the mechanism of protein-bioactive molecule interaction is important for the development protein-based carrier systems. Interaction of b-casein with resveratrol, a natural polyphenol, was studied using ultraviolet-visible absorption and fluorescence spectroscopy. It was found that the interaction shifted the protein fluorophores to a more hydrophilic environment but the polyphenol to a more hydrophobic environment. Formation of the complex with b-casein did not affect trans-cis isomerization of resveratrol or the total antioxidant activity of the protein-polyphenol system, as analyzed respectively using spectrophotometry and 2,2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid assay. The protective effect of resveratrol against the photodecomposition of folic acid was not affected by binding to b-casein. The data obtained should provide insight into protein-polyphenol interaction mechanisms and aid the development of b-casein-based carrier systems for the delivery of bioactive molecules.

scholarly journals Surface coating affects behavior of metallic nanoparticles in a biological environment

2016 ◽  
Vol 7 ◽  
pp. 246-262 ◽  
Author(s):  
Darija Domazet Jurašin ◽  
Marija Ćurlin ◽  
Ivona Capjak ◽  
Tea Crnković ◽  
Marija Lovrić ◽  
...  
Keyword(s):  
Surface Coating ◽  
Metallic Nanoparticles ◽  
Colloidal Stability ◽  
Biological Fluids ◽  
Physicochemical Characterization ◽  
Superparamagnetic Iron Oxide ◽  
Physicochemical Characteristics ◽  
Biological Environment ◽  
Coating Agents ◽  
And Behavior

Silver (AgNPs) and maghemite, i.e., superparamagnetic iron oxide nanoparticles (SPIONs) are promising candidates for new medical applications, which implies the need for strict information regarding their physicochemical characteristics and behavior in a biological environment. The currently developed AgNPs and SPIONs encompass a myriad of sizes and surface coatings, which affect NPs properties and may improve their biocompatibility. This study is aimed to evaluate the effects of surface coating on colloidal stability and behavior of AgNPs and SPIONs in modelled biological environments using dynamic and electrophoretic light scattering techniques, as well as transmission electron microscopy to visualize the behavior of the NP. Three dispersion media were investigated: ultrapure water (UW), biological cell culture medium without addition of protein (BM), and BM supplemented with common serum protein (BMP). The obtained results showed that different coating agents on AgNPs and SPIONs produced different stabilities in the same biological media. The combination of negative charge and high adsorption strength of coating agents proved to be important for achieving good stability of metallic NPs in electrolyte-rich fluids. Most importantly, the presence of proteins provided colloidal stabilization to metallic NPs in biological fluids regardless of their chemical composition, surface structure and surface charge. In addition, an assessment of AgNP and SPION behavior in real biological fluids, rat whole blood (WhBl) and blood plasma (BlPl), revealed that the composition of a biological medium is crucial for the colloidal stability and type of metallic NP transformation. Our results highlight the importance of physicochemical characterization and stability evaluation of metallic NPs in a variety of biological systems including as many NP properties as possible.

scholarly journals Dextran Sulfate/Pramlintide Polyelectrolyte Nanoparticles as a Promising Delivery System: Optimization, Evaluation of Supramolecular Interactions and Effect on Conformational Stability of the Peptide Drug

2021 ◽  
Author(s):  
Carine Zuglianello ◽  
Andrés Chamorro ◽  
Vanessa de Oliveira ◽  
Francisco Xavier Jr. ◽  
Elenara Lemos-Senna
Keyword(s):  
Colloidal Stability ◽  
Dextran Sulfate ◽  
Conformational Stability ◽  
System Optimization ◽  
Physicochemical Characteristics ◽  
Supramolecular Interactions ◽  
New Approach ◽  
Isothermal Titration Microcalorimetry ◽  
Peptide Release ◽  
Helical Content

In this study, we investigated the feasibility to obtain nanoparticles (NPs) by assembling pramlintide (Pram) with dextran sulfate (DexS), as a new approach for mucosal peptide delivery. DexS/Pram NPs were prepared by dropwise addition of a Pram solution to a DexS solution under magnetic stirring. The physicochemical characteristics of NPs and molecular interactions involved in the co-assembling were evaluated by dynamic light scattering (DLS), transmission electronic microscopy (TEM), isothermal titration microcalorimetry, Fourier-transform infrared spectroscopy (FTIR), fluorescence quenching, and circular dichroism (CD). DexS/Pram NPs displayed a narrow size distribution (ca. 200 nm), negative zeta potential (ca. −40 mV), association efficiency close to 100%, and nanogel behavior. The assembling with DexS increased the Pram α-helical content, stabilizing the peptide in its bioactive form. The colloidal stability of nanoparticles was dependent on the salt concentration and it could be assumed that peptide release from nanoparticles occurs by dissociation of the complex at physiological conditions.

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