Effects of Geometric Confinement on Caging and Dynamics of Polymer-Tethered Nanoparticle Suspensions

2020 ◽  
Author(s):  
Xiaotun Liu ◽  
Nyalaliska W. Utomo ◽  
Qing Zhao ◽  
Jingxu Zheng ◽  
Duhan Zhang ◽  
...  
2020 ◽  
Vol 16 (2) ◽  
pp. 204-213 ◽  
Author(s):  
Melissa A. Vetten ◽  
Mary Gulumian

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested. Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions. Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested. Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution. Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.


Author(s):  
Michael Ludwig ◽  
Regine von Klitzing

Complete interaction force profiles of charged surfaces across confined suspensions were successfully described using a superposition of double layer and structural forces.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xingjian Zhang ◽  
Trevor Chan ◽  
Michael Mak

AbstractCancer cell metastasis is a major factor in cancer-related mortality. During the process of metastasis, cancer cells exhibit migratory phenotypes and invade through pores in the dense extracellular matrix. However, the characterization of morphological and subcellular features of cells in similar migratory phenotypes and the effects of geometric confinement on cell morphodynamics are not well understood. Here, we investigate the phenotypes of highly aggressive MDA-MB-231 cells in single cell and cell doublet (an initial and simplified collective state) forms in confined microenvironments. We group phenotypically similar single cells and cell doublets and characterize related morphological and subcellular features. We further detect two distinct migratory phenotypes, fluctuating and non-fluctuating, within the fast migrating single cell group. In addition, we demonstrate an increase in the number of protrusions formed at the leading edge of cells after invasion through geometric confinement. Finally, we track the short and long term effects of varied degrees of confinement on protrusion formation. Overall, our findings elucidate the underlying morphological and subcellular features associated with different single cell and cell doublet phenotypes and the impact of invasion through confined geometry on cell behavior.


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 221
Author(s):  
Argelia Balbuena Balbuena Ortega ◽  
Felix E. Torres-González ◽  
Valentin López López Gayou ◽  
Raul Delgado Delgado Macuil ◽  
Gaetano Assanto ◽  
...  

We carry out an experimental campaign to investigate the nonlinear self-defocusing propagation of singular light beams with various complex structures of phase and intensity in a colloidal suspension of gold nanoparticles with a plasmonic resonance near the laser wavelength (532nm). Studying optical vortices embedded in Gaussian beams, Bessel vortices and Bessel-cosine (necklace) beams, we gather evidence that while intense vortices turn into two-dimensional dark solitons, all structured wavepackets are able to guide a weak Gaussian probe of different wavelength (632.8 nm) along the dark core. The probe confinement also depends on the topological charge of the singular pump.


2014 ◽  
Vol 16 (4) ◽  
Author(s):  
Justin M. Gorham ◽  
Anne B. Rohlfing ◽  
Katrice A. Lippa ◽  
Robert I. MacCuspie ◽  
Amy Hemmati ◽  
...  

2009 ◽  
Vol 189 ◽  
pp. S185
Author(s):  
Tobias Meißner ◽  
Annegret Potthoff ◽  
Volkmar Richter

2017 ◽  
Vol 70 (3) ◽  
pp. 317-323 ◽  
Author(s):  
Elizabeth Mendes de Oliveira ◽  
Edwin Elard Garcia-Rojas ◽  
Izabella Christynne Ribeiro Pinto Valadão ◽  
Adriana de Souza Forster Araújo ◽  
José Adilson de Castro

2015 ◽  
Vol 41 (1) ◽  
pp. 65-68 ◽  
Author(s):  
I. A. Bagrov ◽  
V. V. Danilov ◽  
S. K. Evstrop’ev ◽  
V. M. Kiselev ◽  
I. M. Kislyakov ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document