Polyreactions in oriented systems, 30. Mixed monolayers and liposomes from natural and polymerizable lipids

Büschl, R.; Hupfer, B.; Ringsdorf, Helmut

doi:10.1002/marc.1982.030030902

Cited by 37 publications

(6 citation statements)

References 22 publications

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“…Since diacetylenes polymerize most readily in solidlike states, most studies have focused on conditions that favor domain formation. Phase separation was not observed when ionic diacetylenic lipids were mixed with zwitterionic PC. , …”

Section: Polymerization Of Preexisiting Domainsmentioning

confidence: 94%

“…Ringsdorf and co-workers were the first to describe the polymerization of phase-separated monolayers composed of a diacetylenic PC and a nonpolymerizable lipid, distearoyl PE (DSPE) . Phase separation was also investigated in bilayer systems. , Evidence for phase separation was obtained in calorimetric studies and substantiated by the photopolymerization characteristics of the lipid mixtures. A zwitterionic diacetylenic PC, e.g., 24 , phase separated from nonpolymerizable PC co-lipids at temperatures below their T m .…”

Section: Polymerization Of Preexisiting Domainsmentioning

confidence: 99%

“…Phase separation was not observed when ionic diacetylenic lipids were mixed with zwitterionic PC. 171,172 Ringsdorf and co-workers were the first to describe the polymerization of phase-separated monolayers composed of a diacetylenic PC and a nonpolymerizable lipid, distearoyl PE (DSPE). 173 Phase separation was also investigated in bilayer systems.…”

Section: Polymerization Of Preexisiting Domainsmentioning

confidence: 99%

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Supramolecular Materials via Polymerization of Mesophases of Hydrated Amphiphiles

2002

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Section: Polymerization Of Preexisiting Domainsmentioning

confidence: 94%

Section: Polymerization Of Preexisiting Domainsmentioning

confidence: 99%

Section: Polymerization Of Preexisiting Domainsmentioning

confidence: 99%

See 1 more Smart Citation

Supramolecular Materials via Polymerization of Mesophases of Hydrated Amphiphiles

2002

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“…Polymerized liposomes were originally designed to improve the stability of liposomes as a drug carrier [for reviews, see Regen et al (1987) and Ringsdorf et al (1988)] and have been recently used to study intercellular communications (Dodrer & Regen, 1990; Krisovitch & Regen, 1991). Earlier, Buschl et al (1982) reported that patches of natural phospholipids on the surface of photopolymerized liposomes were hydrolyzed by PLA2 and that these patches could be used as "corks" for the selective opening of polymerized liposomes. In this report, we describe the use of polymerized mixed liposomes to study the interfacial catalysis of PLA2.…”

mentioning

confidence: 99%

Use of polymerized mixed liposomes to study interactions of phospholipase A2 with membranes

Wu¹,

Cho²

1993

Biochemistry

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Polymerized liposomes of thiol-based phospholipids, 1,2-bis[12-(lipoyloxy)dodecanoyl]-sn-glycero-3-phosphocholine (BLPC) and -phosphoglycerol (BLPG) were used to study interactions of several phospholipases A2 (PLA2) with membranes. Large liposomes (an average diameter of 100 +/- 10 nm) prepared from BLPC or BLPG were readily hydrolyzed by PLA2. Once polymerized, however, these liposomes were resistant to the PLA2 hydrolysis. When liposomes were prepared from a mixture of 1-hexadecanoyl-2-(1-pyrenyldecanoyl)-sn-glycero-3-phosphocholine (pyrene-PC) (5 mol%) and BLPC, fluorescence measurements of resulting polymerized mixed liposomes showed that the pyrene-PC molecules exist solely as monomers without forming a patch and were selectively hydrolyzed by PLA2. Progress of the hydrolysis can be readily monitored by measuring the change in fluorescence emission at 380 nm in the presence of bovine serum albumin. Rapid and selective hydrolysis of inserted phospholipids in polymerized mixed liposomes supports the notion that facile migration of a phospholipid substrate from membrane to the active site of enzyme is a critical step in the catalysis of PLA2. On the basis of these findings, various combinations of polymerized mixed liposomes were prepared and their hydrolysis by PLA2 measured. When compared to the substrate specificity of PLA2s determined using Triton X-100/phospholipid mixed micelles, results from polymerized mixed liposomes indicate that electrostatic interactions between the interfacial binding site of PLA2 and membrane surfaces play an important role in the determination of substrate specificity of PLA2 and in the regulation of PLA2 activities.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…Freeze-fracture electron micrograph of: a) a polymeric liposome from a lipid with ammonium b) a phase-separated polymeric liposome containing 30% of headgroup(13,14) DMPC(13,14) For the formation of phase-separated membranes, lipids with fluorocarbon chains are o f special interest. It could be shown that lipids with hydrocarbon and fluorocarbon chains and the same headgroup form a phase-separated membrane(15).…”

mentioning

confidence: 99%

Polymeric monolayers and liposomes as models for biomembranes. How to bridge the gap between polymer science and membrane biology?

1984

Self Cite

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Pclyrnsr chemists as poachers in foreign grounds? Why not? Nscromolecular chemistry has become a mature science with all advantages and handicaps of a well-established scientific discipline: many heights have been conquerred and the harvest is r;b!jnGant, but adventure and the future might be else!vtiere. i n tiii!e of bottomed out industrial profits in common old?tics, future polymer chemistry cannot be limited t o repetitive improvement of already successful mass polymers instead o f material science as well as life science where "polvmer thinking" might help t o lead t o new solutions o f current rob1ems.The first hesitant steps on the bridge towards membrane tiologj nave been made.Can polymer chemists really contribute to the understanding o r even mimicking of cell membrane functions and cell-cell interactio!is? Fascinated by the specificity and efficiency of interactions such as the destruction of tumor cells Dy l y m o b ocytes ( 1 ) and having in mind what biochemical analyses tell us about membrane composition, w e may try t o "synthesize" polymeric membrane and cell models. The commonly used model systems ( 2 ) such as planar lipid monolayers at the gas-water interface, bimolecular lipid membranes and spherical IiDosomes are much less stable than natural membrane systems (Fig. 1). r'This contribiition is an extended abstr3ct of a paper presented at the FKG/USSR-Symposium in Taschkent 13P3. It will be publisned in details elsewhere (Aavances in Polymer Science, 1 9 8 4 1.

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Polyreactions in oriented systems, 30. Mixed monolayers and liposomes from natural and polymerizable lipids

Cited by 37 publications

References 22 publications

Supramolecular Materials via Polymerization of Mesophases of Hydrated Amphiphiles

Supramolecular Materials via Polymerization of Mesophases of Hydrated Amphiphiles

Use of polymerized mixed liposomes to study interactions of phospholipase A2 with membranes

Polymeric monolayers and liposomes as models for biomembranes. How to bridge the gap between polymer science and membrane biology?

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