scholarly journals PEGylation of Superparamagnetic Iron Oxide Nanoparticles with Self-Organizing Polyacrylate-PEG Brushes for Contrast Enhancement in MRI Diagnosis

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 776 ◽  
Author(s):  
Erzsébet Illés ◽  
Márta Szekeres ◽  
Ildikó Tóth ◽  
Katalin Farkas ◽  
Imre Földesi ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Colloidal Stability ◽  
Serum Proteins ◽  
Electrokinetic Potential ◽  
Blood Compatibility ◽  
Superparamagnetic Iron Oxide ◽  
Protein Corona ◽  
Superparamagnetic Nanoparticles ◽  
Mri Diagnosis

For biomedical applications, superparamagnetic nanoparticles (MNPs) have to be coated with a stealth layer that provides colloidal stability in biological media, long enough persistence and circulation times for reaching the expected medical aims, and anchor sites for further attachment of bioactive agents. One of such stealth molecules designed and synthesized by us, poly(polyethylene glycol methacrylate-co-acrylic acid) referred to as P(PEGMA-AA), was demonstrated to make MNPs reasonably resistant to cell internalization, and be an excellent candidate for magnetic hyperthermia treatments in addition to possessing the necessary colloidal stability under physiological conditions (Illés et al. J. Magn. Magn. Mater. 2018, 451, 710–720). In the present work, we elaborated on the molecular background of the formation of the P(PEGMA-AA)-coated MNPs, and of their remarkable colloidal stability and salt tolerance by using potentiometric acid–base titration, adsorption isotherm determination, infrared spectroscopy (FT-IR ATR), dynamic light scattering, and electrokinetic potential determination methods. The P(PEGMA-AA)@MNPs have excellent blood compatibility as demonstrated in blood sedimentation, smears, and white blood cell viability experiments. In addition, blood serum proteins formed a protein corona, protecting the particles against aggregation (found in dynamic light scattering and electrokinetic potential measurements). Our novel particles also proved to be promising candidates for MRI diagnosis, exhibiting one of the highest values of r2 relaxivity (451 mM−1s−1) found in literature.

Enhance the Colloidal Stability of Magnetite Nanoparticles Using Poly(sodium 4-styrene sulfonate) Stabilizers

2014 ◽  
Vol 625 ◽  
pp. 168-171 ◽  
Author(s):  
Qi Hwa Ng ◽  
Jit Kang Lim ◽  
Ahmad Abdul Latif ◽  
Boon Seng Ooi ◽  
Siew Chun Low
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Magnetite Nanoparticles ◽  
Cluster Size ◽  
Environmental Remediation ◽  
Colloidal Stability ◽  
Molar Ratio ◽  
Styrene Sulfonate

The major challenge in assessing the performance of magnetite nanoparticles (MNPs) in removing pollutants from wastewater is the agglomeration of those nanoparticles into a bulky cluster size. In this study, different concentration of poly (sodium 4-styrene sulfonate) (PSS) were coated around the surface of MNPs to increase the particles’ colloidal stability. Both dynamic light scattering (DLS) and thermogravimetric (TGA) analyses have proved the success coating of PSS onto MNPs, whereby the cluster size of the functionalized MNPs were shown notably depends on the applied dosage of PSS. PSS/MNPs functionalization at molar ratio of 6:1 was found to have the smallest cluster size at 148.4 ± 0.22 nm. These results have provided some insight about the particles’ colloidal stability that could be useful for environmental remediation.

scholarly journals Surface characterization of nanoparticles using near-field light scattering

2018 ◽  
Vol 9 ◽  
pp. 1228-1238 ◽  
Author(s):  
Eunsoo Yoo ◽  
Yizhong Liu ◽  
Chukwuazam A Nwasike ◽  
Sebastian R Freeman ◽  
Brian C DiPaolo ◽  
...  
Keyword(s):  
Light Scattering ◽  
Zeta Potential ◽  
Surface Characterization ◽  
Colloidal Stability ◽  
Near Field ◽  
Particle Surface ◽  
Superparamagnetic Iron Oxide ◽  
Scattering Intensity ◽  
Potential Applications ◽  
Poly Ethylene

The effect of nanoparticle surface coating characteristics on colloidal stability in solution is a critical parameter in understanding the potential applications of nanoparticles, especially in biomedicine. Here we explored the modification of the surface of poly(ethylene glycol)-coated superparamagnetic iron oxide nanoparticles (PEG-SPIOs) with the synthetic pseudotannin polygallol via interpolymer complexation (IPC). Changes in particle size and zeta potential were indirectly assessed via differences between PEG-SPIOs and IPC-SPIOs in particle velocity and scattering intensity using near-field light scattering. The local scattering intensity is correlated with the distance between the particle and waveguide, which is affected by the size of the particle (coating thickness) as well as the interactions between the particle and waveguide (related to the zeta potential of the coating). Therefore, we report here the use of near-field light scattering using nanophotonic force microscopy (using a NanoTweezerTM instrument, Halo Labs) to determine the changes that occurred in hydrated particle characteristics, which is accompanied by an analytical model. Furthermore, we found that altering the salt concentration of the suspension solution affected the velocity of particles due to the change of dielectric constant and viscosity of the solution. These findings suggest that this technique is suitable for studying particle surface changes and perhaps can be used to dynamically study reaction kinetics at the particle surface.

scholarly journals pH effect on the synthesis of different size silver nanoparticles evaluated by DLS and their size-dependent antimicrobial activity

2020 ◽  
Vol 25 (4) ◽  
Author(s):  
Leiriana Aparecida Pinto Gontijo ◽  
Ellen Raphael ◽  
Daniela Pereira Santos Ferrari ◽  
Jefferson Luis Ferrari ◽  
Juliana Pereira Lyon ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Size Distribution ◽  
Colloidal Stability ◽  
Chemical Reduction ◽  
Ph Effect ◽  
Antimicrobial Properties ◽  
Size Dependent

ABSTRACT This paper reports citrate-stabilized silver nanoparticles (AgNPs) synthesized by nitrate ion chemical reduction with sodium borohydride, at different pHs (2–9). The AgNPs synthesized by this method exhibited size distribution from 5 to 249 nm, depending on pH, as determined by dynamic light scattering, and morphology spherical, as determined by transmission electron microscopy. In pH range 3–7 occurred aggregation of the nanoparticles. The size distribution depending on pH was determined by dynamic light scattering. The zeta potential was determined, and the colloidal stability was correlated with nanoparticles aggregation at different pHs. The size-dependent antimicrobial activity was evaluated for two solutions, wherein both samples exhibited antimicrobial activity, although the smallest AgNPs without agglomeration have enhanced antimicrobial properties.

Interactive influence of extracellular polymeric substances (EPS) and electrolytes on the colloidal stability of silver nanoparticles

2020 ◽  
Vol 7 (1) ◽  
pp. 186-197 ◽  
Author(s):  
Ishara Fernando ◽  
Dan Lu ◽  
Yan Zhou
Keyword(s):  
Silver Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Electrophoretic Mobility ◽  
Extracellular Polymeric Substances ◽  
Colloidal Stability ◽  
Time Resolved

The colloidal stability of silver nanoparticles (AgNPs) was evaluated using time-resolved dynamic light scattering, electrophoretic mobility and dissolved Ag concentration in the presence of electrolytes and extracellular polymeric substances (EPS).

scholarly journals Colloidal stability of molten salt –based nanofluids: Dynamic Light Scattering tests at high temperature conditions

2019 ◽  
Vol 352 ◽  
pp. 1-10 ◽  
Author(s):  
Nuria Navarrete ◽  
Alexandra Gimeno-Furió ◽  
Josep Forner-Escrig ◽  
J. Enrique Juliá ◽  
Rosa Mondragón
Keyword(s):  
High Temperature ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Molten Salt ◽  
Colloidal Stability ◽  
Temperature Conditions
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