Control of Nanoparticle Release by Membrane Composition for Dual‐Responsive Nanocapsules

2019 ◽  
Vol 25 (60) ◽  
pp. 13694-13700 ◽  
Author(s):  
Xiaoling Liu ◽  
Xueyi Wang ◽  
Brigitte Voit ◽  
Dietmar Appelhans
Keyword(s):  
Membrane Composition ◽  
Dual Responsive ◽  
Nanoparticle Release

Design of dual-responsive nanocarries with high drug loading capacity based on hollow mesoporous organosilica nanoparticles

2019 ◽  
Vol 233 ◽  
pp. 230-235 ◽  
Author(s):  
Li-li Lu ◽  
Wen-ya Xiong ◽  
Jun-bin Ma ◽  
Tian-fang Gao ◽  
Si-yuan Peng ◽  
...  
Keyword(s):  
Drug Loading ◽  
Loading Capacity ◽  
High Drug ◽  
Dual Responsive ◽  
Mesoporous Organosilica ◽  
High Drug Loading

scholarly journals Menaquinone-mediated regulation of membrane fluidity is relevant for fitness of Listeria monocytogenes

2021 ◽  
Author(s):  
Alexander Flegler ◽  
Vanessa Kombeitz ◽  
André Lipski
Keyword(s):  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Membrane Fluidity ◽  
Low Temperatures ◽  
Lipid Membrane ◽  
Feedback Inhibition ◽  
Aromatic Amino Acids ◽  
Adaptation Effect ◽  
Membrane Composition ◽  
Lower Growth

AbstractListeria monocytogenes is a food-borne pathogen with the ability to grow at low temperatures down to − 0.4 °C. Maintaining cytoplasmic membrane fluidity by changing the lipid membrane composition is important during growth at low temperatures. In Listeria monocytogenes, the dominant adaptation effect is the fluidization of the membrane by shortening of fatty acid chain length. In some strains, however, an additional response is the increase in menaquinone content during growth at low temperatures. The increase of this neutral lipid leads to fluidization of the membrane and thus represents a mechanism that is complementary to the fatty acid-mediated modification of membrane fluidity. This study demonstrated that the reduction of menaquinone content for Listeria monocytogenes strains resulted in significantly lower resistance to temperature stress and lower growth rates compared to unaffected control cultures after growth at 6 °C. Menaquinone content was reduced by supplementation with aromatic amino acids, which led to a feedback inhibition of the menaquinone synthesis. Menaquinone-reduced Listeria monocytogenes strains showed reduced bacterial cell fitness. This confirmed the adaptive function of menaquinones for growth at low temperatures of this pathogen.

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.

O-nitrobenzyl Liposomes with Dual-responsive Release Capabilities for Drug Delivery

2021 ◽  
pp. 116016
Author(s):  
Weihe Yao ◽  
Chenyu Liu ◽  
Ning Wang ◽  
Hengjun Zhou ◽  
Farishta Shafiq ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Dual Responsive

scholarly journals Structure and Interdigitation of Chain-Asymmetric Phosphatidylcholines and Milk Sphingomyelin in the Fluid Phase

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1441
Author(s):  
Moritz P. K. Frewein ◽  
Milka Doktorova ◽  
Frederick A. Heberle ◽  
Haden L. Scott ◽  
Enrico F. Semeraro ◽  
...  
Keyword(s):  
Chain Length ◽  
Hydration Shell ◽  
Fluid Phase ◽  
Hydrocarbon Chain ◽  
Specific Model ◽  
Glycerol Backbone ◽  
Membrane Composition ◽  
Membrane Structures ◽  
Hydrocarbon Chain Length ◽  
Dynamics Simulations

We addressed the frequent occurrence of mixed-chain lipids in biological membranes and their impact on membrane structure by studying several chain-asymmetric phosphatidylcholines and the highly asymmetric milk sphingomyelin. Specifically, we report trans-membrane structures of the corresponding fluid lamellar phases using small-angle X-ray and neutron scattering, which were jointly analyzed in terms of a membrane composition-specific model, including a headgroup hydration shell. Focusing on terminal methyl groups at the bilayer center, we found a linear relation between hydrocarbon chain length mismatch and the methyl-overlap for phosphatidylcholines, and a non-negligible impact of the glycerol backbone-tilting, letting the sn1-chain penetrate deeper into the opposing leaflet by half a CH2 group. That is, penetration-depth differences due to the ester-linked hydrocarbons at the glycerol backbone, previously reported for gel phase structures, also extend to the more relevant physiological fluid phase, but are significantly reduced. Moreover, milk sphingomyelin was found to follow the same linear relationship suggesting a similar tilt of the sphingosine backbone. Complementarily performed molecular dynamics simulations revealed that there is always a part of the lipid tails bending back, even if there is a high interdigitation with the opposing chains. The extent of this back-bending was similar to that in chain symmetric bilayers. For both cases of adaptation to chain length mismatch, chain-asymmetry has a large impact on hydrocarbon chain ordering, inducing disorder in the longer of the two hydrocarbons.

Core/Shell Dual‐Responsive Nanocarriers via Iron‐Mineralized Electrostatic Self‐Assembly for Precise Pesticide Delivery

2021 ◽  
pp. 2102027
Author(s):  
Da‐xia Zhang ◽  
Jiang Du ◽  
Rui Wang ◽  
Jian Luo ◽  
Tong‐fang Jing ◽  
...  
Keyword(s):  
Self Assembly ◽  
Core Shell ◽  
Dual Responsive
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