The elucidation of the molecular mechanism of the extrusion process

Doskocz, Joanna (author), Dałek, Paulina (author), Przybyło, Magdalena (author), Trzebicka, Barbara (author), Foryś, Aleksander (author), Kobyliukh, Anastasiia (author), Iglič, Aleš (author), Langner, Marek (author)

Extrusion is a popular method for producing homogenous population of unilamellar liposomes. The technique relies on forcing a lipid suspension through cylindrical pores in a polycarbonate membrane. The quantification of the extrusion and/or recalibration processes make possible the acquisition of experimental data, which can be correlated with the mechanical properties of the lipid bilayer. In this work, the force needed for the extrusion process was correlated with the mechanical properties of a lipid bilayer derived from other experiments. Measurements were performed using a home-made dedicated device capable of maintaining a stable volumetric flux of a liposome suspension through well-defined pores and to continuously measure the extrusion force. Based on the obtained results, the correlation between the lipid bilayer bending rigidity and extrusion force was derived. Specifically, it was found that the bending rigidity of liposomes formed from well-defined lipid mixtures agrees with data obtained by others using flicker-noise spectroscopy or micromanipulation. The other issue addressed in the presented studies was the identification of molecular mechanisms leading to the formation of unilamellar vesicles in the extrusion process. Finally, it was demonstrated that during the extrusion, lipids are not exchanged between vesicles, i.e., vesicles can divide but no membrane fusion or lipid exchange between bilayers was detected.

• Language: English
• Keywords: liposomes, extrusion, lipid bilayer, membrane mechanics, bending rigidity
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering; MF - Faculty of Medicine
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 20 str.
• Numbering: Vol. 14, iss. 15, art. 4278
• PID: 20.500.12556/RUL-135710
• UDC: 577
• ISSN on article: 1996-1944
• DOI: 10.3390/ma14154278
• COBISS.SI-ID: 72250627
• Publication date in RUL: 29.03.2022

Record is a part of a journal

• Title: Materials
• Shortened title: Materials
• Publisher: MDPI
• ISSN: 1996-1944
• COBISS.SI-ID: 33588485

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 01.08.2021

Secondary language

• Language: Slovenian
• Keywords: liposomi, ekstruzija, lipidni dvosloj, membranska mehanika, upogibna togost