Osmotic swelling of phospholipid vesicles causes them to fuse with a planar phospholipid bilayer membrane

Science ◽  
1982 ◽  
Vol 217 (4558) ◽  
pp. 458-460 ◽  
Author(s):  
F. Cohen ◽  
M. Akabas ◽  
A Finkelstein
Keyword(s):  
Bilayer Membrane ◽  
Phospholipid Bilayer ◽  
Phospholipid Vesicles ◽  
Osmotic Swelling ◽  
Phospholipid Bilayer Membrane

scholarly journals Fusion of phospholipid vesicles with planar phospholipid bilayer membranes. I. Discharge of vesicular contents across the planar membrane.

1980 ◽  
Vol 75 (3) ◽  
pp. 241-250 ◽  
Author(s):  
J Zimmerberg ◽  
F S Cohen ◽  
A Finkelstein
Keyword(s):  
Bilayer Membrane ◽  
Convincing Evidence ◽  
Water Soluble ◽  
Phospholipid Bilayer ◽  
Phospholipid Vesicles ◽  
Biological Phenomenon ◽  
Vesicle Membrane ◽  
Bilayer Membranes ◽  
Phospholipid Bilayer Membrane ◽  
Planar Membrane

Multilamellar phospholipid vesicles are introduced into the cis compartment on one side of a planar phospholipid bilayer membrane. The vesicles contain a water-soluble fluorescent dye trapped in the aqueous phases between the lamellae. If a vesicle containing n lamellae fuses with a planar membrane, an n-1 lamellar vesicle should be discharged into the opposite trans compartment, where it would appear as a discernible fluorescent particle. Thus, fusion events can be assayed by counting the number of fluorescent particles appearing in the trans compartment. In the absence of divalent cation, fusion does not occur, even after vesicles have been in the cis compartment for 40 min. When CaCl2 is introduced into the cis compartment to a concentration of greater than or equal to 20 mM, fusion occurs within the next 20 min; it generally ceases thereafter because of vesicle aggregation in the cis compartment. With approximately 3 x 10(8) vesicles/cm3 in the cis compartment, about 25-50 fusion events occur following CaCl2 addition. The discharge of vesicular contents across the planar membrane is the most convincing evidence of vesicle-membrane fusion and serves as a model for that ubiquitous biological phenomenon--exocytosis.

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.

Synthetic, Sodium-Ion-Conducting Tris(Macrocycle) Channels that Function in a Phospholipid Bilayer Membrane: An Overview

2000 ◽  
Vol 12 (1) ◽  
pp. 13-22
Author(s):  
Stephen L. De Wall ◽  
Eric S. Meadows ◽  
Clare L. Murray ◽  
Hossein Shabany ◽  
George W. Gokel
Keyword(s):  
Bilayer Membrane ◽  
Sodium Ion ◽  
Phospholipid Bilayer ◽  
Phospholipid Bilayer Membrane ◽  
Ion Conducting

Design of artificial membrane transporters from gold nanoparticles with controllable hydrophobicity

2016 ◽  
Vol 191 ◽  
pp. 495-510 ◽  
Author(s):  
Marcin P. Grzelczak ◽  
Alexander P. Hill ◽  
Domagoj Belic ◽  
Dan F. Bradley ◽  
Casper Kunstmann-Olsen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Phase Transfer ◽  
Aqueous Dispersion ◽  
Bilayer Membrane ◽  
Phospholipid Bilayer ◽  
Potassium Ions ◽  
Vesicle Membrane ◽  
Ligand Shell ◽  
Phospholipid Bilayer Membrane ◽  
Liquid Systems

Gold nanoparticles with variable hydrophobicity have been prepared in three different size regimes following established methods. The control of hydrophobicity was achieved by complexation of the 18-crown-6-CH2-thiolate ligand shell with potassium ions. Potassium dependent phase transfer of these particles from dispersion in water to chloroform was demonstrated, and the equilibrium partitioning of the particles in water–chloroform liquid/liquid systems was quantified by optical spectroscopy. The gradual complexation of the ligand shell with potassium ions was further monitored by zeta potential measurements. Potassium dependent insertion of nanoparticles into the phospholipid bilayer membrane of vesicles in aqueous dispersion has been demonstrated by cryogenic transmission electron microscopy (cryo-TEM). Nanoparticle-dependent potassium ion transport across the vesicle membrane has been established by monitoring the membrane potential with fluorescence spectroscopy using a potential sensitive dye.

scholarly journals mTHPC-Loaded Extracellular Vesicles Significantly Improve mTHPC Diffusion and Photodynamic Activity in Preclinical Models

Pharmaceutics ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 676
Author(s):  
Marie Millard ◽  
Solène Posty ◽  
Max Piffoux ◽  
Jordane Jasniewski ◽  
Henri-Pierre Lassalle ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Human Colon ◽  
Bilayer Membrane ◽  
Phospholipid Bilayer ◽  
Phospholipid Bilayer Membrane ◽  
Photodynamic Activity ◽  
Ht 29 ◽  
Determinant Factor

Extracellular vesicles (EVs), derived from the cell, display a phospholipid bilayer membrane that protects the cargo molecules from degradation and contributes to increasing their stability in the bloodstream and tumor targeting. EVs are interesting in regard to the delivery of photosensitizers (PSs) used in the photodynamic therapy (PDT), as they allow us to overcome the limitations observed with liposomes. In fact, liposomal formulation of meta-tetra(hydroxyphenyl)chlorin (mTHPC) (Foslip®), one of the most potent clinically approved PSs, is rapidly destroyed in circulation, thus decreasing in vivo PDT efficacy. mTHPC-EV uptake was evaluated in vitro in a 3D human colon HT-29 microtumor and in vivo study was performed in HT-29 xenografted mice. The obtained data were compared with Foslip®. After intravenous injection of the mTHPC formulations, biodistribution, pharmacokinetics and PDT-induced tumor regrowth were evaluated. In a 3D model of cells, mTHPC-EV uptake featured a deeper penetration after 24h incubation compared to liposomal mTHPC. In vivo results showed a considerable improvement of 33% tumor cure with PDT treatment applied 24h after injection, while 0% was observed after Foslip®/PDT. Moreover, 47 days were required to obtain ten times the initial tumor volume after mTHPC-EVs/PDT compared to 30 days for liposomal mTHPC. In conclusion, compared to Foslip®, mTHPC-EVs improved mTHPC biodistribution and PDT efficacy in vivo. We deduced that a major determinant factor for the improved in vivo PDT efficacy is the deep mTHPC intratumor penetration.

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