Liposome-Cell Interaction: Transfer and Intracellular Release of a Trapped Fluorescent Marker

Weinstein, John N.; Yoshikami, S.; Henkart, Pierre A.; Blumenthal, Robert; Hagins, W. A.

doi:10.1126/science.835007

Cited by 688 publications

(286 citation statements)

References 25 publications

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“…As anticipated, CF in PS:PE liposomes gave rise to intense diffuse intracellular fluorescence (not shown) that represents dye free in the cytoplasm [25]. The emergence of cytoplasmic CF fluorescence was inhibited both by chloroquine and by azide/2-deoxyglucose.…”

Section: Time Minsupporting

confidence: 75%

pH‐sensitive liposomes mediate cytoplasmic delivery of encapsulated macromolecules

1985

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Negatively charged liposomes are endocytosed by the coated vesicle system and accumufate in acidic intracellular vesicles. Liposomes that become unstable at acidic pH improve cytoplasmic delivery of membraneimpermeant macromolecules such as calcein (CAL) and FITC dextran (18 or 40 kDa). Oleic acid (OA): phosphatidylethanolamine (PE) (3 : 7 mole ratio) liposomes become permeable to CAL at pH < 7.0. Control liposomes of phosphatidylserine : PE or OA: phosphatidylcholine are stable at pH 4-8. OA : PE liposomes promote cytoplasmic delivery of encapsulated CAL to CV-1 cells, as evidenced by the emergence of diffuse, cytoplasmic CAL fluorescence. Delivery requires metabolic energy and is partially inhibited by chloroquine or monensin, which raise the pH of intracellular vesicies. Liposome Endocytosis Miwoinjection

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Section: Time Minsupporting

confidence: 75%

pH‐sensitive liposomes mediate cytoplasmic delivery of encapsulated macromolecules

1985

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“…To determine the pattern of movement of a probe inserted directly into sperm membrane, thereby avoiding linkage to external reporters, we treated spermatids with vesicles of the fluorescent phospholipid analogue, NBD-PC . These vesicles are invisible under fluorescent illumination because the fluorophores are so concentrated that they are self-quenched (21,30) . When NBD-PC molecules transfer from the vesicles to the sperm membrane the dilution of the fluorophore in the membrane lipids results in dequenching, a more than two-thousandfold increase in fluorescence, revealing the location of the fluorescent phospholipid in the membrane.…”

Section: Redistribution Of Membrane-integrated Phospholipid During DImentioning

confidence: 99%

Membrane flow during nematode spermiogenesis.

Roberts¹,

Ward²

1982

The Journal of Cell Biology

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Two distinct types of surface membrane rearrangement occur during the differentiation of Caenorhabditis elegans spermatids into amoeboid spermatozoa. The first, detected by the behavior of latex beads attached to the surface, is a nondirected, intermittent movement of discrete portions of the membrane . This movement starts when spermatids are stimulated to differentiate and stops when a pseudopod is formed . The second type of movement is a directed, continual flow of membrane components from the tip of the pseudopod to its base . Both membrane glycoproteins and fluorescent phospholipids inserted in the membrane flow backward at the same rate,^-4 Lm/min, although their lateral diffusion coefficients in the membrane differ by at least a factor of 5 . These observations suggest that pseudopodial membrane movement is due to bulk flow of membrane components away from the tip of the pseudopod.Membrane components move over the surfaces of many cell types, particularly motile cells . These movements can occur without net membrane rearrangement as typified by the bidirectional movement of surface-attached latex beads on the flagellar membrane of Chlamydomonas (6). More often, membrane movement is unidirectional resulting in net rearrangement of membrane components. This is the case for capping of externally cross-linked antigens, lectin receptors and insulin receptors on lymphocytes (23, 24), and for "tipping" of sexual agglutinins on adherent Chlamydomonas gametes (11) . Amoeboid cells exhibit yet another form of directed membrane movement in which surface markers are transported centripetally from the leading edge toward the cell body (1) . Neither the mechanisms underlying these movements nor their physiological significance are understood.In this study, we have examined membrane movements during differentiation of the amoeboid spermatozoa of the nematode, Caenorhabditis elegans. The terminal step in differentiation of these cells is the rapid conversion of spherical, sessile spermatids into polarized, motile spermatozoa. This event can be induced in vitro with the monovalent ion ionophore, monensin (18). It requires extensive cytoplasmic rearrangements : laminar membranes underlying plasma membrane in spermatids accumulate at the base of the pseudopod; membranous organelles (MO) fuse with the plasma membrane; and a pseudopod, which is devoid of organelles but filled with amorphous cytoplasm, extends 3-4 lam from the hemispherical cell body (18,29) .Here, we demonstrate that extensive surface membrane rearrangement accompanies this cytoplasmic differentiation .

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“…It has been observed that in solutions containing high concentrations of CF (more than 10 mM), the fluorescence emission declines rapidly because of interactions between fluorophore mole- cules. 52 Thus, a dispersion of vesicles containing 50 mM of CF fluoresces slightly, while the release of the dye into the external medium, hence dilution, results in the relief of the selfquenching and in a marked increase in fluorescence intensity. 41,51,52 Herein the release of CF from polymersomes into Tris-HCl buffer, pH 7.4, was monitored at 25 and 37 o C and the typical release profiles are shown in Figure 4(a).…”

Section: 폴리머 제37권 제3호 2013년mentioning

confidence: 99%

“…52 Thus, a dispersion of vesicles containing 50 mM of CF fluoresces slightly, while the release of the dye into the external medium, hence dilution, results in the relief of the selfquenching and in a marked increase in fluorescence intensity. 41,51,52 Herein the release of CF from polymersomes into Tris-HCl buffer, pH 7.4, was monitored at 25 and 37 o C and the typical release profiles are shown in Figure 4(a). The release is 38% at the beginning of the experiment (around 40 min after gel filtration), and lasts about 3 weeks at both temperatures.…”

Section: 폴리머 제37권 제3호 2013년mentioning

confidence: 99%

Characterization and Release Behavior of Polymersomes of PEG-Poly(fumaric-sebacic acids)-PEG Triblock Copolymer in Aqueous Solution

Pourhosseini¹,

Saboury²,

Najafi³

et al. 2013

Polymer Korea

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Polymersomes made of biodegradable triblock copolymers based on poly(fumaric acid-co-sebacoyl chloride)/ PEG (PEG-co-P(FA/SC)-co-PEG) were prepared and studied in aqueous solutions. TEM confirmed the formation of vesicles in aqueous media. Aggregation behavior of the copolymers was studied by fluorescence spectroscopy of 8-anilino-1-naphthalenesulfonic acid, and the critical aggregation concentration (c.a.c.) of the copolymer was found to be ~26.2 µM indicating desirable stability of the vesicles. Dynamic light scattering revealed that the size of the vesicles was distributed within the range of 170-270 nm. Turbidity measurements confirmed the relative short-term stability of the polymersomes. Carboxyfluorescein, a hydrophilic compound, was simply encapsulated in the vesicles during polymersome preparation. The release of encapsulant from the polymersomes at 25 and 37 o C lasted about 3 weeks, and the rate of release followed a first-order kinetics. The release is speculated to be primarily carried out through diffusion. These results confirm that these polymersomes are promising as controlled-release carriers of various drugs.

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Liposome-Cell Interaction: Transfer and Intracellular Release of a Trapped Fluorescent Marker

Cited by 688 publications

References 25 publications

pH‐sensitive liposomes mediate cytoplasmic delivery of encapsulated macromolecules

pH‐sensitive liposomes mediate cytoplasmic delivery of encapsulated macromolecules

Membrane flow during nematode spermiogenesis.

Characterization and Release Behavior of Polymersomes of PEG-Poly(fumaric-sebacic acids)-PEG Triblock Copolymer in Aqueous Solution

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