Comparative Properties and Methods of Preparation of Lipid Vesicles (Liposomes)

Szoka, F; Papahadjopoulos, D.

doi:10.1146/annurev.bb.09.060180.002343

Cited by 1,421 publications

(721 citation statements)

References 2 publications

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“…The formation of structures such as cylindrical micelles and lamellar sheets during the formation of lipid vesicles by detergent dialysis is well established. [24][25][26] The results presented here indicate that by using the appropriate amount of citrate to shield the positive charge on the lipid structures containing higher amounts of cationic lipid, the affinity of the plasmid for these intermediates can be reduced to levels compatible with good entrapment. Within this model citrate concentrations below the optimum range do not result in adequate shielding of the positively charged lipid structures formed during dialysis, resulting in crosslinking by plasmids and aggregate formation.…”

Section: Discussionmentioning

confidence: 96%

Stabilized plasmid-lipid particles for regional gene therapy: formulation and transfection properties

et al. 1999

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Previous work (Wheeler et al, Gene Therapy 1999; 6: 271-be generated. The SPLP produced could be isolated from 281) has shown that plasmid DNA can be entrapped in empty vesicles by sucrose density gradient centrifugation, 'stabilized plasmid-lipid particles' (SPLP) containing the and exhibited a narrow size distribution (62 ± 8 nm, as fusogenic lipid dioleoylphosphatidylethanolamine (DOPE), determined by freeze-fracture electron microscopy) and a low levels (5-10 mol%) of cationic lipid, and stabilized by high plasmid-to-lipid ratio of 65 g/ mol (corresponding to a polyethyleneglycol (PEG) coating. The PEG moieties are one plasmid per particle) regardless of the DODAC conattached to a ceramide anchor containing an arachidoyl tent. It was found that isolated SPLP containing 20-acyl group (PEG-CerC 20 ). These SPLP exhibit low trans-24 mol% DODAC resulted in optimum transfection of COSfection potencies in vitro, due in part to the long residence 7 and HepG2 cells in vitro, with luciferase expression levels time of the PEG-CerC 20 on the SPLP surface. In this work comparable to those achieved for plasmid DNA-cationic we employed SPLP stabilized by PEG attached to ceralipid complexes. In vivo studies employing an intraperimide containing an octanoyl acyl group (PEG-CerC 8 ), toneal B16 tumor model and intraperitoneal administration which is able to quickly exchange out of the SPLP, to of SPLP also demonstrated maximum luciferase develop systems that give rise to optimized in vitro and in expression for DODAC contents of 20-24 mol% and sigvivo (regional) transfection. A particular objective was to nificantly improved gene expression in tumor tissue as achieve cationic lipid contents that give rise to maximum compared with complexes. We conclude that SPLP stabiltransfection levels. It is shown that by performing the dialyized by PEG-CerC 8 and containing 20-24 mol% cationic sis procedure in the presence of increasing concentrations lipid are attractive alternatives to plasmid DNA-cationic of citrate, SPLP containing up to 30 mol% of the cationic lipid complexes for regional gene therapy applications. lipid dioleoydimethylammonium chloride (DODAC) could

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Section: Discussionmentioning

confidence: 96%

Stabilized plasmid-lipid particles for regional gene therapy: formulation and transfection properties

et al. 1999

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“…Liposomes were prepared according to a modified protocol from the standard method revised by Szoka and Papahadjopoulos [34]. POPC (1-palmitoyl-2-oleoyl-snglycero-3-phosphocholine) was obtained from Avanti Polar-Lipids (purity >99.9%) and a 5 mM stock solution in a chloroform:methanol (2:1) solvent was prepared, 0.5 ml of the stock solution were dried using a rotary evaporator Heidolph VV-micro and a vacuum pump Büchi V-500 (with a V-800 vacuum control) during approximately 1 h. The resulting lipid film on the flask walls was hydrated at 30°C (well above the main phase transition temperature of POPC, À2°C) for about 1 h and vortexed regularly to produce a suspension with multilamellar vesicles.…”

Section: Proteins and Vesicles Preparationsmentioning

confidence: 99%

Decavanadate interactions with actin: Inhibition of G-actin polymerization and stabilization of decameric vanadate

Ramos

Manuel

Tiago

et al. 2006

Journal of Inorganic Biochemistry

101

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Decameric vanadate species (V10) inhibit the rate and the extent of G-actin polymerization with an IC50 of 68 ± 22 lM and 17 ± 2 lM, respectively, whilst they induce F-actin depolymerization at a lower extent. On contrary, no effect on actin polymerization and depolymerization was detected for 2 mM concentration of ''metavanadate'' solution that contains ortho and metavanadate species, as observed by combining kinetic with 51 V NMR spectroscopy studies. Although at 25°C, decameric vanadate (10 lM) is unstable in the assay medium, and decomposes following a first-order kinetic, in the presence of G-actin (up to 8 lM), the half-life increases 5-fold (from 5 to 27 h). However, the addition of ATP (0.2 mM) in the medium not only prevents the inhibition of G-actin polymerization by V10 but it also decreases the half-life of decomposition of decameric vanadate species from 27 to 10 h. Decameric vanadate is also stabilized by the sarcoplasmic reticulum vesicles, which raise the half-life time from 5 to 18 h whereas no effects were observed in the presence of phosphatidylcholine liposomes, myosin or G-actin alone. It is proposed that the ''decavanadate'' interaction with G-actin, favored by the G-actin polymerization, stabilizes decameric vanadate species and induces inhibition of G-actin polymerization. Decameric vanadate stabilization by cytoskeletal and transmembrane proteins can account, at least in part, for decavanadate toxicity reported in the evaluation of vanadium (V) effects in biological systems.

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“…The S and ! c parameters were measured at a temperature above (33°C) and below (10°C) the gel-to-fluid transition temperature (23.9°C) of DMPC [30][31][32]. In the fluid state (33°C), local microviscosities of DMPC membrane measured at depths of 7.8 (5-DSA) and 27.7 Å (16-DSA) were 177.92 and 42.29 cP, respectively.…”

Section: Propofol Effects Probed By Esrmentioning

confidence: 99%

Does propofol alter membrane fluidity at clinically relevant concentrations? An ESR spin label study

Bahri

Seret

Hans³

et al. 2007

Biophysical Chemistry

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Comparative Properties and Methods of Preparation of Lipid Vesicles (Liposomes)

Cited by 1,421 publications

References 2 publications

Stabilized plasmid-lipid particles for regional gene therapy: formulation and transfection properties

Stabilized plasmid-lipid particles for regional gene therapy: formulation and transfection properties

Decavanadate interactions with actin: Inhibition of G-actin polymerization and stabilization of decameric vanadate

Does propofol alter membrane fluidity at clinically relevant concentrations? An ESR spin label study

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