Characterization of liposomes prepared using a microemulsifier

Mayhew, E.; Lazo, R.; Vail, William J.; King, J.S.; Green, A.M.

doi:10.1016/0005-2736(84)90167-6

Cited by 114 publications

(28 citation statements)

References 4 publications

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“…Regardless, we have been able to prepare liposome/DNA complexes using cationic lipid/EPC mixtures that exhibit the same size distribution as cationic lipid/DOPE mixtures through the use of ultrasonic cavitation. We suggest that other methods of size reduction, which employ mechanical force based on cavitation, such as homogenization, 53 high-pressure extrusion, 54 or microfluidization, [55][56][57] may also be able to produce particles of small, uniform diameter from these complexes.…”

Section: Discussionmentioning

confidence: 99%

Plasmid DNA is Protected against Ultrasonic Cavitation-Induced Damage when Complexed to Cationic Liposomes

Wasan¹,

Reimer²,

Bally³

1996

Journal of Pharmaceutical Sciences

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Cationic liposomes bound to plasmid DNA are currently used for in vitro and in vivo gene therapy applications, but such complexes readily form large, heterogeneous aggregates that are not appropriate for pharmaceutical development. More importantly, size heterogeneity makes studies focused on optimizing gene transfer to cells difficult to conduct or understand. For this reason we have evaluated the effect of microprobe sonication on these complexes in an effort to achieve process-controlled size homogeneity. Complexes were prepared using a 7.2 kb reporter plasmid and the following liposomal lipid combinations: DDAB/DOPE (50:50 mol %), DDAB/DOPE/PEG-PE (50:45:5 mol %), DDAB/EPC (50:50 mol %), DDAB/EPC/PEG-PE (50:45:5, 50:40:10, 50:35:15 mol %), DODAC/DOPE (50:50 mol %), and DODAC/EPC (50:50 mol %) (DDAB, dimethyldioctadecylammonium bromide; DOPE, dioleoylphosphatidylethanolamine; PEG-PE, monomethoxypolyethylene glycol2000 succinate- distearoylphosphatidylethanolamine; EPC, egg phosphatidylcholine; DODAC, dioleoyldimethylammonium chloride). The influence of complex composition and lipid:DNA ratio was evaluated. Particle size was determined before and after complexation and again after sonication using the quasi-elastic light scattering technique. DNA integrity was assessed via agarose gel electrophoresis. Finally, gene transfection was evaluated using CHO cells that were transfected in vitro with sonicated and unsonicated complexes. It is established in this study that size reduction can occur, but this is dependent on cationic and neutral lipid composition and, in some cases, lipid:DNA ratio. Surprisingly, the process of sonication leaves a significant percentage of the plasmid DNA intact and capable of in vitro transfection. This study shows that plasmid DNA can be protected from damage due to sonication by liposome complex formation. This may indicate that more common pharmaceutical methods for size reduction which subject particles to mechanical stress may be applicable in preparation of liposome/DNA formulations for in vivo application.

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Section: Discussionmentioning

confidence: 99%

Plasmid DNA is Protected against Ultrasonic Cavitation-Induced Damage when Complexed to Cationic Liposomes

Wasan¹,

Reimer²,

Bally³

1996

Journal of Pharmaceutical Sciences

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“…Homogenization techniques depend on high-velocity collisions to reduce particle size. Mayhew et al [45] have developed a microemulsifier that splits a sample of large, heterogeneous lipid particles into two streams and recombine them in a continuous, multicycle, high-velocity, high shear-force collision, producing monodisperse liposomes with a diameter of less than 100 nm [3]. In membrane extrusion, size is reduced by passing the liposomes through a membrane filter of defined pore size.…”

Section: Preparation Of Liposomesmentioning

confidence: 99%

Design of liposomal formulations for cell targeting

Nogueira

Gomes

Preto

et al. 2015

Colloids and Surfaces B: Biointerfaces

140

103

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Liposomes have gained extensive attention as carriers for a wide range of drugs due to being both nontoxic and biodegradable as they are composed of substances naturally occurring in biological membranes. Active targeting for cells has explored specific modification of the liposome surface by functionalizing it with specific targeting ligands in order to increase accumulation and intracellular uptake into target cells. None of the Food and Drug Administration-licensed liposomes or lipid nanoparticles are coated with ligands or target moieties to delivery for homing drugs to target tissues, cells or subcellular organelles. Targeted therapies (with or without controlled drug release) are an emerging and relevant research area. Despite of the numerous liposomes reviews published in the last decades, this area is in constant development. Updates urgently needed to integrate new advances in targeted liposomes research. This review highlights the evolution of liposomes from passive to active targeting and challenges in the development of targeted liposomes for specific therapies.

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“…The standard thin-film liposome preparation method usually gives a hydrophilic entrapment efficiency of only 1-9%, but repeated freezing and thawing of the solution can increase the efficiency to 35-88%. Mayhew et al [13] used a Microfluidizer to encapsulate cytosine arabinoside, and obtained entrapment efficiencies ranging from 5-75% depending on the operating conditions and phospholipid concentration.…”

Section: Introductionmentioning

confidence: 99%

Comparison of hydrophobic and hydrophilic encapsulation using liposomes prepared from milk fat globule-derived phospholipids and soya phospholipids

Thompson

Couchoud

Singh

2009

Dairy Sci. Technol.

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-Liposomes prepared from a milk fat globule membrane (MFGM) phospholipid fraction have been shown to have significantly different physical and chemical characteristics and appeared to be more stable in a variety of conditions than liposomes prepared from soya phospholipid material. These liposome systems were used to try to encapsulate model hydrophobic (β-carotene) and hydrophilic (potassium chromate) compounds. Liposomes produced from the MFGM-derived phospholipids showed significantly higher entrapment efficiencies for both β-carotene and potassium chromate. The differences were particularly apparent when using the hydrophobic molecules at low ratios of β-carotene to phospholipid. It is likely that the improved incorporation efficiency for β-carotene is due to the partitioning of the molecule between the aqueous phase and the phospholipid membrane, a property which will be dependent on the specific composition of the phospholipid material used. The higher encapsulation efficiency for the potassium chromate appeared to reflect the slightly larger diameter of the liposomes produced from the MFGM material. These results suggest that there may be inherent advantages in the use of liposomes prepared from MFGM-derived phospholipids via microfluidization for the encapsulation of both hydrophobic and hydrophilic compounds.

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Characterization of liposomes prepared using a microemulsifier

Cited by 114 publications

References 4 publications

Plasmid DNA is Protected against Ultrasonic Cavitation-Induced Damage when Complexed to Cationic Liposomes

Plasmid DNA is Protected against Ultrasonic Cavitation-Induced Damage when Complexed to Cationic Liposomes

Design of liposomal formulations for cell targeting

Comparison of hydrophobic and hydrophilic encapsulation using liposomes prepared from milk fat globule-derived phospholipids and soya phospholipids

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