Liposome Extrusion
Liposome Extrusion - Related Videos
11:35
Constant Pressure-controlled Extrusion Method for the Preparation of Nano-sized Lipid Vesicles
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Cited by 29 •
2012
This protocol describes an extrusion method for preparing lipid vesicles of sub-micron sizes with a high degree of homogeneity. This method uses a pressure-controlled system with controlled nitrogen flow rates for liposome preparation. The lipid preparation1,2, liposome extrusion, and size characterization will be presented herein.
10:22
Demonstration of the Power Law Model Through Extrusion
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2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Polymer melts are often formed into simple shapes or "extrudates", such as cylindrical pellets, flat sheets, or pipe, using an extruder.1 Polyolefins are among the most common extrudable polymers. Extrusion involves transporting and melting solid feed, which is sometimes mixed with non-polymeric materials, and the pressure build-up and transport of the melt or mixture.
09:39
Live Imaging of Cell Extrusion from the Epidermis of Developing Zebrafish
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Cited by 20 •
2011
Dying cells are extruded from epithelial tissues by concerted contraction of neighboring cells without disrupting barrier function. The optical clarity of developing zebrafish provides an excellent system to visualize extrusion in living epithelia. Here we describe methods to induce and image extrusion in the larval zebrafish epidermis at cellular resolution.
09:03
Giant Liposome Preparation for Imaging and Patch-Clamp Electrophysiology
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Cited by 23 •
2013
Reconstituting functional membrane proteins into giant liposomes of defined composition is a powerful approach when combined with patch-clamp electrophysiology. However, conventional giant liposome production may be incompatible with protein stability. We describe protocols for producing giant liposomes from pure lipids or small liposomes containing ion channels.
07:47
Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance
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Cited by 17 •
2015
AN MRI-compatible custom-designed laser-based heating apparatus has been developed to provide local heating of subcutaneous tumors in order to activate release of agents from thermosensitive liposomes specifically at the tumor region.
FAQs
Membrane pore size is a major determinant of the vesicle diameter obtained after processing. As heterogeneous or larger liposomes pass through defined pores, they are reshaped toward sizes associated with the membrane openings. Selecting an appropriate pore size therefore helps narrow the size distribution, improving formulation consistency for later bioengineering experiments and carrier development.
Repeated extrusion cycles give vesicles multiple opportunities to pass through the membrane and undergo controlled reshaping. Additional passages can reduce the remaining heterogeneity in the suspension, producing a more uniform population than a single passage may provide. The number of cycles is therefore an important process variable when researchers seek reproducible liposome dimensions.
Temperature and lipid composition affect how the membrane responds during passage through the pores, which can influence vesicle diameter and lamellarity, meaning the number of lipid bilayer layers surrounding a vesicle. These variables should be considered alongside pore size and extrusion cycles because formulation conditions can change the physical characteristics and consistency of the resulting liposomes.
A typical workflow requires a liposome suspension, a membrane containing defined pores, and a means of applying pressure to drive the suspension through the membrane. The suspension is passed through the membrane repeatedly while researchers control relevant conditions such as temperature and account for lipid composition. The processed material can then be evaluated for size distribution and lamellarity.
Consistency improves when researchers control the variables that shape vesicle formation during processing, especially membrane pore size, extrusion cycles, temperature, and lipid composition. Keeping these factors defined allows different preparations to be compared more reliably. In bioengineering, this reproducibility supports controlled studies of membrane behavior and the development of engineered carriers with more consistent physical properties.
The technique supports both fundamental and applied work. Researchers can use the resulting liposomes to study membrane behavior under controlled size and lamellarity conditions, or to prepare more consistent carriers for drugs, nucleic acids, imaging agents, and other therapeutic or diagnostic cargos. Better-defined vesicle populations help connect formulation variables with carrier performance in drug-delivery and related studies.