scholarly journals pH-triggered endosomal escape of pore-forming Listeriolysin O toxin-coated gold nanoparticles

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Ismael Plaza-GA ◽  
Vanesa Manzaneda-González ◽  
Matic Kisovec ◽  
Víctor Almendro-Vedia ◽  
Mónica Muñoz-Úbeda ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Host Cell ◽  
Self Assembly ◽  
Specific Binding ◽  
Bacterial Pathogen ◽  
Endosomal Escape ◽  
Surface Immobilization ◽  
Listeriolysin O ◽  
Endosomal Acidification ◽  
Major Bottleneck

Abstract Background A major bottleneck in drug delivery is the breakdown and degradation of the delivery system through the endosomal/lysosomal network of the host cell, hampering the correct delivery of the drug of interest. In nature, the bacterial pathogen Listeria monocytogenes has developed a strategy to secrete Listeriolysin O (LLO) toxin as a tool to escape the eukaryotic lysosomal system upon infection, allowing it to grow and proliferate unharmed inside the host cell. Results As a “proof of concept”, we present here the use of purified His-LLO H311A mutant protein and its conjugation on the surface of gold nanoparticles to promote the lysosomal escape of 40 nm-sized nanoparticles in mouse embryonic fibroblasts. Surface immobilization of LLO was achieved after specific functionalization of the nanoparticles with nitrile acetic acid, enabling the specific binding of histidine-tagged proteins. Conclusions Endosomal acidification leads to release of the LLO protein from the nanoparticle surface and its self-assembly into a 300 Å pore that perforates the endosomal/lysosomal membrane, enabling the escape of nanoparticles.

scholarly journals Selective Detection of Human Lung Adenocarcinoma Cells Based on the Aptamer-Conjugated Self-Assembled Monolayer of Gold Nanoparticles

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 195 ◽  
Author(s):  
Ngoc-Viet Nguyen ◽  
Chun-Ping Jen
Keyword(s):  
Gold Nanoparticles ◽  
Self Assembly ◽  
Human Lung ◽  
Specific Binding ◽  
Physical And Mechanical Properties ◽  
Target Cells ◽  
Self Assembled Monolayer ◽  
Assembly Method ◽  
Human Lung Adenocarcinoma Cells ◽  
Self Assembled

This study established a microfluidic chip for the capture of A549 human lung circulating tumor cells via the aptamer-conjugated self-assembled monolayer (SAM) of gold nanoparticles (AuNPs) in the channel. AuNPs are among the most attractive nanomaterials for the signal enhancement of biosensors owing to their unique chemical, physical, and mechanical properties. The microchip was fabricated using soft photolithography and casting and molding techniques. A self-assembly method was designed to attach AuNPs, cell-specific aptamers, and target cells onto the desired area (i.e., SAM area). In this study, the gold microelectrode configuration was characterized by fluorescence microscopy and impedance measurements to confirm the important modification steps. Subsequently, several investigations with the proposed assay were conducted with different cell samples to determine the specific binding ability of the device for A549 adenocarcinoma cancer cells. This work has ensured a simple, convenient, selective, and sensitive approach for the development of biosensors for lung cancer detection during the early stages.

scholarly journals Layer by Layer Assembled Chitosan-Coated Gold Nanoparticles for Enhanced siRNA Delivery and Silencing

2021 ◽  
Vol 22 (2) ◽  
pp. 831
Author(s):  
Elnaz Shaabani ◽  
Maryam Sharifiaghdam ◽  
Herlinde De Keersmaecker ◽  
Riet De Rycke ◽  
Stefaan De Smedt ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Self Assembly ◽  
Fluorescent Protein ◽  
Transfection Efficiency ◽  
Direct Reduction ◽  
Sirna Delivery ◽  
Lung Epithelial Cells ◽  
Endosomal Escape ◽  
Layer By Layer ◽  
Assembly Method

Delivery of small interfering RNA (siRNA) provides one of the most powerful strategies for downregulation of therapeutic targets. Despite the widely explored capabilities of this strategy, intracellular delivery is hindered by a lack of carriers that have high stability, low toxicity and high transfection efficiency. Here we propose a layer by layer (LBL) self-assembly method to fabricate chitosan-coated gold nanoparticles (CS-AuNPs) as a more stable and efficient siRNA delivery system. Direct reduction of HAuCl4 in the presence of chitosan led to the formation of positively charged CS-AuNPs, which were subsequently modified with a layer of siRNA cargo molecules and a final chitosan layer to protect the siRNA and to have a net positive charge for good interaction with cells. Cytotoxicity, uptake, and downregulation of enhanced Green Fluorescent Protein (eGFP) in H1299-eGFP lung epithelial cells indicated that LBL-CS-AuNPs provided excellent protection of siRNA against enzymatic degradation, ensured good uptake in cells by endocytosis, facilitated endosomal escape of siRNA, and improved the overall silencing effect in comparison with commercial transfection reagents Lipofectamine and jetPEI®. Therefore, this work shows that LBL assembled CS-AuNPs are promising nanocarriers for enhanced intracellular siRNA delivery and silencing.

A New Immunosensor for Serum Myeloperoxidase Based on Self-Assembly of Multi-Walled Carbon Nanotubes/Thionine/Gold Nanoparticles-Chitosan

2011 ◽  
Vol 343-344 ◽  
pp. 1207-1211 ◽  
Author(s):  
Qi Zhi Diao ◽  
Yuan Li ◽  
Mi Zhou ◽  
Guo Ming Xie
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Self Assembly ◽  
Specific Binding ◽  
Electrochemical Immunosensor ◽  
Enzyme Linked Immunosorbent Assay ◽  
Current Signal ◽  
Multi Walled Carbon Nanotubes ◽  
Response Current ◽  
Walled Carbon Nanotubes

A new electrochemical immunosensor for serum myeloperoxidase (MPO) has been developed based on the self-assembly multilays of multi-walled carbon nanotubes (MWNTs), thionine (THI), gold nanoparticles (GNPs) and chitosanon (CHIT) on the glassy carbon electrode (GCE). The antibody of MPO (anti-MPO) was absorbed on the surface of GNPs monolayer. Horseradish peroxidase (HRP) was employed to block non-specific binding and amplify the response current signal. It was observed that the peak current was linear with the MPO concentration in a range of 2.5-125 µgl-1. The detection limit was 1.425 µgl-1 (S/N=3). Correlation analysis showed that this new immunosensor assay has a significant correlation with enzyme-linked immunosorbent assay (ELISA) (r=0.96, p>0.05) for 40 clinical specimens.

scholarly journals DNA-mediated self-assembly of gold nanoparticles on protein superhelix

2018 ◽  
Author(s):  
Tao Zhang ◽  
Ingemar André
Keyword(s):  
Gold Nanoparticles ◽  
Self Assembly ◽  
De Novo ◽  
Specific Binding ◽  
Protein Structures ◽  
Spatial Arrangement ◽  
Inorganic Nanoparticles ◽  
Covalent Attachment ◽  
Site Specific ◽  
Conjugation Method

AbstractRecent advances in protein engineering have enabled methods to control the self-assembly of protein on various length-scales. One attractive application for designed proteins is to direct the spatial arrangement of nanomaterials of interest. Until now, however, a reliable conjugation method is missing to facilitate site-specific positioning. In particular, bare inorganic nanoparticles tend to aggregate in the presence of buffer conditions that are often required for the formation of stable proteins. Here, we demonstrated a DNA mediated conjugation method to link gold nanoparticles with protein structures. To achieve this, we constructed de novo designed protein fibers based on previously published uniform alpha-helical units. DNA modification rendered gold nanoparticles with increased stability against ionic solutions and the use of complementary strands hybridization guaranteed the site-specific binding to the protein. The combination of high resolution placement of anchor points in designed protein assemblies with the increased control of covalent attachment through DNA binding can enable investigations of multilevel physical coupling events of nanocomponents on protein templates and expand the application of protein structures to material sciences.

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...

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