Inhibition of dehydration-induced fusion between liposomal membranes by carbohydrates as measured by fluorescence energy transfer

Womersley, Christopher; Uster, Paul S.; Rudolph, Alan S.; Crowe, John H.

doi:10.1016/0011-2240(86)90050-7

Cited by 86 publications

(34 citation statements)

References 32 publications

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“…Freeze-fracture shows that when vesicles or liposomes are dehydrated, massive fusion results (Crowe et al, 1983;Crowe et al, 1985b). Similar studies using resonance energy transfer MacDonald & MacDonald, 1981;Womersley et al, 1986), freezefracture (Madden et al, 1985;Pick, 1981;, and n.m.r. to monitor fusion induced by freezing or dehydration also show without question that the result is fusion between neighbouring bilayers.…”

Section: Water and Phospholipidsmentioning

confidence: 70%

“…Why the sugars differ in their ability to stabilize vesicles and membranes is a subject of some interest that is under study in several laboratories other than our own (e.g. Madden et al, 1985;Gaber et al, 1986;Lee et al, 1986; al., 1986;Womersley et al, 1986). Typical results with resonance energy transfer (Fig.…”

Section: Effects Of Sugars On Stability Of Dry Vesiclesmentioning

confidence: 99%

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Stabilization of dry phospholipid bilayers and proteins by sugars

Crowe¹,

Crowe²,

Carpenter³

et al. 1987

Biochemical Journal

834

484

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Section: Water and Phospholipidsmentioning

confidence: 70%

Section: Effects Of Sugars On Stability Of Dry Vesiclesmentioning

confidence: 99%

Stabilization of dry phospholipid bilayers and proteins by sugars

Crowe¹,

Crowe²,

Carpenter³

et al. 1987

Biochemical Journal

834

484

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“…This suggestion was based on the occurrence of high levels of disaccharides in desiccation-tolerant organisms (1,8,24,25,28) and on studies in vitro of their protective effect on isolated membranes (7), liposomal membranes (15,31), and proteins (4, 5) during drying and rehydration. Trehalose is the predominant disaccharide in organisms such as yeasts, fungi, the desert resurrection plant Selaginella (19), and microscopic animals (8), whereas anhydrobiotic organs of higher plants accumulate mainly sucrose (1,24,25) or combinations of sucrose, raffinose, and stachyose (1,28).…”

mentioning

confidence: 99%

Effect of Sucrose on Phase Behavior of Membranes in Intact Pollen of Typha latifolia L., as Measured with Fourier Transform Infrared Spectroscopy

Hoekstra

Crowe²,

Crowe³

1991

Plant Physiol.

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In previous studies, we have shown that the temperature dependent vibrational frequency of the CH2 stretch in hydrocarbons in intact pollen grains can be recorded with Fourier transform infrared spectroscopy and used to measure phase transition temperatures (Tm) in these hydrocarbons. Circumstantial evidence was provided that the major contribution to the signal seen in these samples was from membrane phospholipids, and that sucrose in the dry pollen grains reduced Tm of those phospholipids. In the current study, we clarify why a major constituent of the pollen grains, neutral lipids contained in discrete lipid droplets, does not contribute significantly to the signal. Further, we have isolated membranes from the pollen and show that Tm in the isolated membranes rises from -60C in the hydrated membranes to 580C when the membranes are dried without the addition of sucrose. However, when the isolated membranes are dried in the presence of increasing amounts of sucrose, Tm fell steadily, reaching a minimal value of 310C, a figure in good agreement with that seen in the intact pollen grains. The amount of sucrose required to depress Tm maximally in these membranes is also apparently in agreement with that found in the intact pollen, suggesting that sucrose depresses Tm in the pollen.Certain disaccharides, such as trehalose and sucrose, apparently play a role in the acquisition of desiccation tolerance in living organisms. This suggestion was based on the occurrence of high levels of disaccharides in desiccation-tolerant organisms (1,8,24,25,28) and on studies in vitro of their protective effect on isolated membranes (7), liposomal membranes (15, 31), and proteins (4, 5) during drying and rehydration. Trehalose is the predominant disaccharide in organisms such as yeasts, fungi, the desert resurrection plant Selaginella (19), and microscopic animals (8), whereas anhydrobiotic organs of higher plants accumulate mainly sucrose (1,24,25)

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“…Those studies have shown that the sugars that are the best preservation agents also most strongly inhibit fusion during freezing (5,6,8,10) or freeze-drying (3). However, the amount of sugar required to inhibit fusion is much less than that required to prevent leakage, so inhibition of fusion alone is clearly not the sole mechanism of preservation (3).…”

Section: Introductionmentioning

confidence: 99%

Preservation of dry liposomes does not require retention of residual water.

Crowe¹,

Spargo²,

Crowe³

1987

Proc. Natl. Acad. Sci. U.S.A.

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Certain sugars, particularly trehalose, dramatically alter physical properties of dry phospholipids in ways that mimic the presence of water. As a result, these sugars are capable of preserving the integrity of dry liposomes and membranes. Since these effects could conceivably be due to the presence of small amounts of water in the dry preparations of sugar and lipid, we have done careful measurements of the residual water contents in the dry samples and report the results here. Lyophilized liposomes composed of palmitoyloleoylphosphatidylcholine and phosphatidylserine (9:1) contain at most 0.2 mol of H20 per mol of lipid. When the trehalose concentration in the dry mixtures is increased, there is no increase in the apparent water content of the samples over a wide range of sugar concentrations. Over the same range of trehalose contents the maximal effect of trehalose on physical properties of the lipids and on stabilization of liposomes is achieved. We conclude that the stabilization does not require retention of residual amounts of water in the dry trehalosephospholipid preparations. Similar studies with other sugars show a relationship between the amount of sugar interacting with the lipid and the ability of the same sugar to stabilize dry liposomes.In view of their practical potential as vehicles for delivery of water-soluble drugs to cells in whole organisms (e.g., ref. 1), stabilization of liposomes for long-term storage is an important, practical problem. We (2, 3) and others (4-6) have addressed this problem and have found that liposomes can be preserved quite effectively by freezing (5-8) or freeze-drying (2-5) in the presence of certain sugars. For example, when liposomes were freeze-dried in the presence of adequate amounts of trehalose, they were found upon rehydration to have retained as much as 100% of their original contents (2-4). By contrast, when they were freeze-dried without sugar, upon rehydration they leaked essentially all of their contents. Some of the same sugars that are effective at preserving dry liposomes are also remarkably effective at stabilizing structure and function in dry biological membranes (9).In an effort toward understanding the mechanism by which sugars preserve dry liposomes and membranes, we have studied over the past few years the effects of sugars on physical properties of phospholipids. Those studies have shown that the sugars that are the best preservation agents also most strongly inhibit fusion during freezing (5,6,8,10) or freeze-drying (3). However, the amount of sugar required to inhibit fusion is much less than that required to prevent leakage, so inhibition of fusion alone is clearly not the sole mechanism of preservation (3). The same sugars are very effective at reducing the transition temperature (Tm) for the dry lipids, thus potentially maintaining them in a fluid phase in the absence of water (3,6,11). We previously suggested that the dry lipids were in liquid crystalline phase above Tm, but more recent evidence (12) suggests that it is a fluid ...

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Inhibition of dehydration-induced fusion between liposomal membranes by carbohydrates as measured by fluorescence energy transfer

Cited by 86 publications

References 32 publications

Stabilization of dry phospholipid bilayers and proteins by sugars

Stabilization of dry phospholipid bilayers and proteins by sugars

Effect of Sucrose on Phase Behavior of Membranes in Intact Pollen of Typha latifolia L., as Measured with Fourier Transform Infrared Spectroscopy

Preservation of dry liposomes does not require retention of residual water.

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