scholarly journals Influence of the glycocalyx and plasma membrane composition on amphiphilic gold nanoparticle association with erythrocytes

Nanoscale ◽  
2015 ◽  
Vol 7 (26) ◽  
pp. 11420-11432 ◽  
Author(s):  
Prabhani U. Atukorale ◽  
Yu-Sang Yang ◽  
Ahmet Bekdemir ◽  
Randy P. Carney ◽  
Paulo J. Silva ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Plasma Membrane ◽  
Gold Nanoparticle ◽  
Erythrocyte Membranes ◽  
Membrane Composition ◽  
Membrane Components

Amphiphilic gold nanoparticles spontaneously insert into erythrocyte membranes; we characterize this association as a function of key plasma membrane components.

scholarly journals Regulation of Wnt Signaling Pathways at the Plasma Membrane and Their Misregulation in Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Yagmur Azbazdar ◽  
Mustafa Karabicici ◽  
Esra Erdal ◽  
Gunes Ozhan
Keyword(s):  
Plasma Membrane ◽  
Wnt Signaling ◽  
Signaling Pathways ◽  
Cancer Progression ◽  
Malignant Tumors ◽  
Wnt Signaling Pathway ◽  
Receptor Complex ◽  
Breast Cancers ◽  
Membrane Composition ◽  
Membrane Components

Wnt signaling is one of the key signaling pathways that govern numerous physiological activities such as growth, differentiation and migration during development and homeostasis. As pathway misregulation has been extensively linked to pathological processes including malignant tumors, a thorough understanding of pathway regulation is essential for development of effective therapeutic approaches. A prominent feature of cancer cells is that they significantly differ from healthy cells with respect to their plasma membrane composition and lipid organization. Here, we review the key role of membrane composition and lipid order in activation of Wnt signaling pathway by tightly regulating formation and interactions of the Wnt-receptor complex. We also discuss in detail how plasma membrane components, in particular the ligands, (co)receptors and extracellular or membrane-bound modulators, of Wnt pathways are affected in lung, colorectal, liver and breast cancers that have been associated with abnormal activation of Wnt signaling. Wnt-receptor complex components and their modulators are frequently misexpressed in these cancers and this appears to correlate with metastasis and cancer progression. Thus, composition and organization of the plasma membrane can be exploited to develop new anticancer drugs that are targeted in a highly specific manner to the Wnt-receptor complex, rendering a more effective therapeutic outcome possible.

scholarly journals Components of the plasma membrane of growing axons. I. Size and distribution of intramembrane particles.

1984 ◽  
Vol 98 (4) ◽  
pp. 1422-1433 ◽  
Author(s):  
R K Small ◽  
K H Pfenninger
Keyword(s):  
Plasma Membrane ◽  
Growth Cone ◽  
Freeze Fracture ◽  
Particle Diameter ◽  
Lateral Diffusion ◽  
Membrane Composition ◽  
Intramembrane Particles ◽  
Cellular Processes ◽  
Discrete Domains ◽  
Membrane Components

The plasmalemma of mature and growing olfactory axons of the bullfrog has been studied by freeze-fracture. Intramembrane particles (IMPs) of mature olfactory axons are found to be uniformly distributed along the shaft. However, during growth, a decreasing gradient of IMP density is evident along the somatofugal axis. The size histograms of axolemmal IMPs from different segments of growing nerve reveal regional differences in the particle composition. The distribution of each individual size class of particles along the growing nerve forms a decreasing gradient in the somatofugal direction; the slope of these gradients varies directly with particle diameter. These size-dependent density gradients are consistent with a process of lateral diffusion of membrane components that are inserted proximally into the plasma membrane. The membrane composition of the growth cone, however, appears to be independent of these diffusion gradients; it displays a mosaic pattern of discrete domains of high and low particle densities. The relative IMP profiles of these growth cone regions are similar to one another but contain higher densities of large IMPs than the neighboring axonal shaft. The shifting distributions of intramembrane particles that characterize the sprouting neuron give new insights into cellular processes that may underlie the establishment of the functional polarity of the neuron and into the dynamics of axolemmal maturation.

scholarly journals Acquisition of mitogenic responsiveness by nonresponding lymphocytes upon insertion of appropriate membrane components.

1982 ◽  
Vol 156 (4) ◽  
pp. 1274-1279 ◽  
Author(s):  
A Jakobovits ◽  
N Sharon ◽  
I Zan-Bar
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
B Cells ◽  
Concanavalin A ◽  
Sendai Virus ◽  
Interleukin 2 ◽  
Membrane Composition ◽  
Membrane Components

The effect of insertion of plasma membrane components from lymphocytes responding to mitogens into the membranes of nonresponding cells using Sendai virus envelopes as vehicles was examined. T cells modified by B membranes were stimulated by lipopolysaccharide (LPS) to proliferate as well as to produce interleukin-2 activity. B cells modified by T membranes were stimulated by concanavalin A to proliferate and to produce interleukin-2 activity. B cells derived from C3H/HeJ LPS-nonresponder strain of mice, when modified by B membranes derived from the LPS-responder C3H/eb strain, acquired LPS responsiveness. These findings indicate that the inability of either T or B cells to respond to specific mitogens is due to the lack of suitable plasma membrane constituents and that by changing the membrane composition the lymphocytes can be endowed with new functions.

Interference of Gold Nanoparticles with In vitro Endotoxin Detection Assays

2020 ◽  
Vol 16 (2) ◽  
pp. 204-213 ◽  
Author(s):  
Melissa A. Vetten ◽  
Mary Gulumian
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Surface Reactivity ◽  
In Vitro Assays ◽  
Limulus Amebocyte Lysate ◽  
Chromogenic Assay ◽  
Nanoparticle Suspensions ◽  
Endotoxin Contamination ◽  
Factor C

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.

scholarly journals Osmotic stress and vesiculation as key mechanisms controlling bacterial sensitivity and resistance to TiO2 nanoparticles

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Christophe Pagnout ◽  
Angelina Razafitianamaharavo ◽  
Bénédicte Sohm ◽  
Céline Caillet ◽  
Audrey Beaussart ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Osmotic Stress ◽  
Inner Core ◽  
Metal Oxide Nanoparticles ◽  
Membrane Vesicles ◽  
Outer Core ◽  
Membrane Composition ◽  
Cell Turgor ◽  
Bacterial Sensitivity ◽  
Membrane Components

AbstractToxicity mechanisms of metal oxide nanoparticles towards bacteria and underlying roles of membrane composition are still debated. Herein, the response of lipopolysaccharide-truncated Escherichia coli K12 mutants to TiO2 nanoparticles (TiO2NPs, exposure in dark) is addressed at the molecular, single cell, and population levels by transcriptomics, fluorescence assays, cell nanomechanics and electrohydrodynamics. We show that outer core-free lipopolysaccharides featuring intact inner core increase cell sensitivity to TiO2NPs. TiO2NPs operate as membrane strippers, which induce osmotic stress, inactivate cell osmoregulation and initiate lipid peroxidation, which ultimately leads to genesis of membrane vesicles. In itself, truncation of lipopolysaccharide inner core triggers membrane permeabilization/depolarization, lipid peroxidation and hypervesiculation. In turn, it favors the regulation of TiO2NP-mediated changes in cell Turgor stress and leads to efficient vesicle-facilitated release of damaged membrane components. Remarkably, vesicles further act as electrostatic baits for TiO2NPs, thereby mitigating TiO2NPs toxicity. Altogether, we highlight antagonistic lipopolysaccharide-dependent bacterial responses to nanoparticles and we show that the destabilized membrane can generate unexpected resistance phenotype.

scholarly journals CRISPR/Cas12a-mediated gold nanoparticle aggregation for colorimetric detection of SARS-CoV-2

2021 ◽  
Author(s):  
Yiren Cao ◽  
Jinjun Wu ◽  
Bo Pang ◽  
Hongquan Zhang ◽  
X. Chris Le
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Colorimetric Detection ◽  
Isothermal Amplification ◽  
Nanoparticle Aggregation ◽  
Cleavage Activity ◽  
Gold Nanoparticle Aggregation

The trans-cleavage activity of the target-activated CRISPR-Cas12a liberated an RNA crosslinker from a molecular transducer, which facilitated assembly of gold nanoparticles. Integration of the molecular transducer with isothermal amplification and...

Fluorescence biosensor for Salmonella typhimurium detection in food based on nano-self-assembly of alendronic acid modified upconversion and gold nanoparticles

2021 ◽  
Author(s):  
Min Chen ◽  
Leiqing Pan ◽  
K. Tu
Keyword(s):  
Gold Nanoparticles ◽  
Salmonella Typhimurium ◽  
Gold Nanoparticle ◽  
Alendronic Acid ◽  
Self Assembly ◽  
Upconversion Nanoparticles ◽  
Fluorescent Biosensor ◽  
Fluorescence Biosensor

A simple and quick responsive fluorescent biosensor for Salmonella typhimurium detection based on the recognition of aptamer coupled with alendronic acid (ADA)@upconversion nanoparticles (UCNPs) and gold nanoparticle (AuNPs) has been...

scholarly journals Enhanced Extracellular Synthesis of Gold Nanoparticles by Soluble Extracts from Escherichia coli Transformed with Rhizobium tropici Phytochelatin Synthase Gene

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 472
Author(s):  
Qunying Yuan ◽  
Manjula Bomma ◽  
Zhigang Xiao
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Synthesis Method ◽  
Nanoparticle Synthesis ◽  
Morphological Properties ◽  
Phytochelatin Synthase ◽  
Rhizobium Tropici ◽  
Whole Cells ◽  
E Coli ◽  
Recombinant Cells

Phytochelatins, the enzymatic products of phytochelatin synthase, play a principal role in protecting the plants from heavy metal and metalloid toxicity due to their ability to scavenge metal ions. In the present study, we investigated the capacity of soluble intracellular extracts from E. coli cells expressing R. tropici phytochelatin synthase to synthesize gold nanoparticle. We discovered that the reaction mediated by soluble extracts from the recombinant E. coli cells had a higher yield of gold nanoparticles, compared to that from the control cells. The compositional and morphological properties of the gold nanoparticles synthesized by the intracellular extracts from recombinant cells and control cells were similar. In addition, this extracellular nanoparticle synthesis method produced purer gold nanoparticles, avoiding the isolation of nanoparticles from cellular debris when whole cells are used to synthesize nanoparticles. Our results suggested that phytochelatins can improve the efficiency of gold nanoparticle synthesis mediated by bacterial soluble intracellular extracts, and the potential of extracellular nanoparticle synthesis platform for the production of nanoparticles in large quantity and pure form is worth further investigation.

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