Selective Transport of ATP across a Phospholipid Bilayer by a Molecular Umbrella

2003 ◽  
Vol 125 (15) ◽  
pp. 4436-4437 ◽  
Author(s):  
Vaclav Janout ◽  
Bingwen Jing ◽  
Irina V. Staina ◽  
Steven L. Regen
Keyword(s):  
Phospholipid Bilayer ◽  
Selective Transport

Selective transport of Pb2+ and Cd2+ across a phospholipid bilayer by a cyclohexanemonocarboxylic acid-capped 15-crown-5 ether

2006 ◽  
Vol 100 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Shawn A. Hamidinia ◽  
Gregory E. Steinbaugh ◽  
Warren L. Erdahl ◽  
Richard W. Taylor ◽  
Douglas R. Pfeiffer
Keyword(s):  
Phospholipid Bilayer ◽  
Selective Transport

Factors Affecting the lnteraction of Tissue Factor/Factor Vll with Factor X in a Heterogeneous Tubular Reactor

1991 ◽  
Vol 65 (02) ◽  
pp. 139-143 ◽  
Author(s):  
Cynthia H Gemmell ◽  
Vincet T Turitto ◽  
Yale Nemerson
Keyword(s):  
Steady State ◽  
Tissue Factor ◽  
Factor Viia ◽  
Transmembrane Protein ◽  
Strong Association ◽  
Tubular Reactor ◽  
Factor Xa ◽  
Phospholipid Bilayer ◽  
Factor Vii ◽  
Factor X

SummaryA novel reactor recently described for studying phospholipiddependent blood coagulation reactions under flow conditions similar to those occurring in the vasculature has been further charactenzed. The reactor is a capitlary whose inner wall is coated with a stable phospholipid bilayer (or two bilayers) containing tissue factor, a transmembrane protein that is required for the enzymatic activation of factor X by factor VIIa. Perfusion of the capillary at wall shear rates ranging from 25 s−1 to 1,200 s−1 with purified bovine factors X and VIIa led to steady state factor Xa levels at the outlet. Assay were performed using a chromogenic substrate, SpectrozymeTMFXa, or by using a radiometric technique. In the absence of Ca2+ or factor VIIa there was no product formation. No difference was noted in the levels of factor Xa achieved when non-activated factor VII was perfused. Once steady state was achieved further factor Xa production continued in the absence of factor VIIa implying a very strong association of factor VIIa with the tissue factor in the phospholipid membrane. In agreement with static vesicle-type studies the reactor was sensitive to wall tissue factor concentration, temperature and the presence of phosphatidylserine in the bilayer.

scholarly journals Evaluation of the correlation between porphyrin accumulation in cancer cells and functional positions for application as a drug carrier

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Koshi Nishida ◽  
Toshifumi Tojo ◽  
Takeshi Kondo ◽  
Makoto Yuasa
Keyword(s):  
Cancer Cells ◽  
Drug Carrier ◽  
Bilayer Membrane ◽  
Phospholipid Bilayer ◽  
Membrane Permeation ◽  
Porphyrin Derivatives ◽  
Phospholipid Bilayer Membrane ◽  
Meso Position ◽  
Tumor Accumulation ◽  
Binding Position

AbstractPorphyrin derivatives accumulate selectively in cancer cells and are can be used as carriers of drugs. Until now, the substituents that bind to porphyrins (mainly at the meso-position) have been actively investigated, but the effect of the functional porphyrin positions (β-, meso-position) on tumor accumulation has not been investigated. Therefore, we investigated the correlation between the functional position of substituents and the accumulation of porphyrins in cancer cells using cancer cells. We found that the meso-derivative showed higher accumulation in cancer cells than the β-derivative, and porphyrins with less bulky substituent actively accumulate in cancer cells. When evaluating the intracellular distribution of porphyrin, we found that porphyrin was internalized by endocytosis and direct membrane permeation. As factors involved in these two permeation mechanisms, we evaluated the affinity between porphyrin-protein (endocytosis) and the permeability to the phospholipid bilayer membrane (direct membrane permeation). We found that the binding position of porphyrin affects the factors involved in the transmembrane permeation mechanisms and impacts the accumulation in cancer cells.

scholarly journals Molecularly imprinted membrane for transport of urea, creatinine, and vitamin B12 as a hemodialysis candidate membrane

2021 ◽  
Vol 19 (1) ◽  
pp. 806-817
Author(s):  
Muhammad Cholid Djunaidi ◽  
Nabilah Anindita Febriola ◽  
Abdul Haris
Keyword(s):  
Polyethylene Glycol ◽  
Vitamin B12 ◽  
Kidney Function ◽  
Cross Linking ◽  
Vitamin B ◽  
Molecularly Imprinted ◽  
Selective Transport ◽  
Molecularly Imprinted Membrane ◽  
Better Than ◽  
Imprinted Membrane

Abstract High levels of urea and creatinine in the blood are a sign of decreased kidney function. To remove these substances from the blood, hemodialysis which utilizes membranes could be used. In this study, a molecularly imprinted membrane (MIM) was synthesized for the selective transport of urea. The synthesis is initiated with the polymerization of eugenol into polyeugenol and then into polyeugenoxy acetate (PA). The PA is then contacted with urea and then used as the functional polymer in the synthesis of MIM with polysulfone as the membrane base, and polyethylene glycol as the cross-linking agent. The result was later analyzed with FTIR and SEM-EDX. The membrane is then used in the transport of urea, creatinine, and vitamin B12 and then compared with the non-imprinted membrane (NIM) performance. By using UV-Vis spectrophotometry, the results showed that the membrane with 10 h heating variation is able to transport more urea and is more selective than NIM; this proves that the urea template on the MIM enables it to recognize urea molecules better than creatinine and vitamin B12. The order of transport from the best results is urea > creatinine > vitamin B12.

scholarly journals Recent Advancements in Polymer/Liposome Assembly for Drug Delivery: From Surface Modifications to Hybrid Vesicles

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1027
Author(s):  
Vincenzo De Leo ◽  
Francesco Milano ◽  
Angela Agostiano ◽  
Lucia Catucci
Keyword(s):  
Drug Delivery ◽  
First Generation ◽  
Phospholipid Bilayer ◽  
Bioactive Molecules ◽  
Systemic Delivery ◽  
Molecular Weights ◽  
Liposome Preparation ◽  
Wide Range ◽  
Liposome Surface

Liposomes are consolidated and attractive biomimetic nanocarriers widely used in the field of drug delivery. The structural versatility of liposomes has been exploited for the development of various carriers for the topical or systemic delivery of drugs and bioactive molecules, with the possibility of increasing their bioavailability and stability, and modulating and directing their release, while limiting the side effects at the same time. Nevertheless, first-generation vesicles suffer from some limitations including physical instability, short in vivo circulation lifetime, reduced payload, uncontrolled release properties, and low targeting abilities. Therefore, liposome preparation technology soon took advantage of the possibility of improving vesicle performance using both natural and synthetic polymers. Polymers can easily be synthesized in a controlled manner over a wide range of molecular weights and in a low dispersity range. Their properties are widely tunable and therefore allow the low chemical versatility typical of lipids to be overcome. Moreover, depending on their structure, polymers can be used to create a simple covering on the liposome surface or to intercalate in the phospholipid bilayer to give rise to real hybrid structures. This review illustrates the main strategies implemented in the field of polymer/liposome assembly for drug delivery, with a look at the most recent publications without neglecting basic concepts for a simple and complete understanding by the reader.

An Ion Transport Switch Based on Light-Responsive Conformation-Dependent G-Quadruplex Transmembrane Channels

2021 ◽  
Author(s):  
Chunying Li ◽  
Hui Chen ◽  
Xiaohai Yang ◽  
Kemin Wang ◽  
Jianbo Liu
Keyword(s):  
Ion Transport ◽  
Selective Transport ◽  
G Quadruplex ◽  
Transmembrane Channels

A light-responsive ion transport switch has been developed based on conformation-dependent azobenzene-incorporated lipophilic G-quadruplex channels, which provides a new smart approach for the selective transport of K+ ions across the...

scholarly journals Selective Transport of Airborne Microparticles Through Micro-channels Under Microgravity

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Monia Makhoul ◽  
Philippe Beltrame
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Bifurcation Analysis ◽  
Metal Particles ◽  
Microgravity Environment ◽  
Ratchet Effect ◽  
Selective Transport ◽  
Microgravity Experiments ◽  
Particle Drift ◽  
Micro Channels

AbstractThis paper analyzes the possibility of obtaining the selective transport of microparticles suspended in air in a microgravity environment through modulated channels without net displacement of air. Using numerical simulation and bifurcation analysis tools, we show the existence of intermittent particle drift under the Stokes assumption of the fluid flow. The particle transport can be selective and the direction of transport is controlled only by the kind of pumping used. The selective transport is interpreted as a deterministic ratchet effect due to spatial variations in the flow and the particle drag. This ratchet phenomenon could be applied to the selective transport of metal particles during the short duration of microgravity experiments.

scholarly journals Development of discoidal phospholipid bilayer nanoparticles with styrene maleic acid copolymer for diagnosis and therapy of intractable cancers

2021 ◽  
Vol 96-97 ◽  
pp. S83
Author(s):  
Masayuki Munekane ◽  
Wakana Yamaguchi ◽  
Kohei Sano ◽  
Toshihide Yamasaki ◽  
Masafumi Tanaka ◽  
...  
Keyword(s):  
Maleic Acid ◽  
Phospholipid Bilayer ◽  
Diagnosis And Therapy ◽  
Acid Copolymer ◽  
Maleic Acid Copolymer

scholarly journals The impact of orally administered gadolinium orthovanadate GdVO4:Eu3+ nanoparticles on the state of phospholipid bilayer of erythrocytes

2020 ◽  
Vol 45 (4) ◽  
pp. 389-395
Author(s):  
Anton Tkachenko ◽  
Anatolii Onishchenko ◽  
Vladimir Klochkov ◽  
Nataliya Kavok ◽  
Oksana Nakonechna ◽  
...  
Keyword(s):  
Fluorescent Probes ◽  
Lipid Membranes ◽  
Chemical Properties ◽  
Proton Donor ◽  
The State ◽  
Phospholipid Bilayer ◽  
Erythrocyte Membranes ◽  
Control Group ◽  
Donor Ability ◽  
The Impact

AbstractObjectivesTo assess the state of phospholipid bilayer of red blood cells (RBCs) in rats orally exposed to gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) during two weeks using fluorescent probes − ortho-hydroxy derivatives of 2,5-diaryl-1,3-oxazole.MethodsSteady-state fluorescence spectroscopy: a study by the environment-sensitive fluorescent probes − 2-(2′-OH-phenyl)-5-phenyl-1,3-oxazole (probe O1O) and 2-(2′-OH-phenyl)-phenanthro[9,10]-1,3-oxazole (probe PH7).ResultsNo significant changes are detected in the spectra of the fluorescent probes bound to the RBCs from the rats orally exposed to nanoparticles in comparison with the corresponding spectra of the probes bound to the cells from the control group of animals. This indicates that, in case of the rats orally exposed to nanoparticles, no noticeable changes in physico-chemical properties (i.e., in the polarity and the proton-donor ability) are observed in the lipid membranes of RBCs in the region, where the probes locate.ConclusionsNo changes in the physical and chemical properties of the erythrocyte membranes are detected in the region from glycerol backbones of phospholipids to the center of the phospholipid bilayer in the rats orally exposed to VNPs during 2 weeks.

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