Back to Journals » International Journal of Nanomedicine » Volume 7

Influence of charge ratio of liposome/DNA complexes on their size after extrusion and transfection efficiency

Authors Brgles M, Šantak M, Halassy B, Forcic D, Tomašić J

Received 19 October 2011

Accepted for publication 13 November 2011

Published 25 January 2012 Volume 2012:7 Pages 393—401

DOI https://doi.org/10.2147/IJN.S27471

Review by Single-blind

Peer reviewer comments 2


Marija Brgles, Maja Šantak, Beata Halassy, Dubravko Forcic, Jelka Tomašic
Institute of Immunology, Research and Development Department, Zagreb, Croatia

Background: Physicochemical characteristics of liposome/DNA complexes influence transfection efficiency and affect each other in a very intricate way. The result of this is discrepancies in conclusions drawn about the individual influence of each one.
Methods: Aiming to elucidate the influence of liposome/DNA charge ratio and size on transfection efficiency and on each other, we used liposome/DNA complexes with charge ratio (+/-) in the range of 1–50 and extruded through membranes of 400, 200, and 100 nm. Plasmid DNA encoding green fluorescent protein was used to measure transfection efficiency by flow cytometry. Sizes of liposome/DNA complexes were measured by dynamic light scattering.
Results: Liposome size was reduced after extrusion but this was mainly driven by the charge ratio and not by the size of the membrane pores. Reduction of complex size at each charge ratio positively correlated with transfection efficiency. When the size of the complexes was approximately constant, increasing the charge ratio was found to promote transfection efficiency. Cationic lipid N-(1-(2,3-dioleoyloxy)propyl)N,N,N trimethylammonium chloride was used for modulation of positive charge and a cytotoxicity test showed that increasing its amount increases cytotoxicity.
Conclusion: It can be concluded that charge ratio dictates the size of the complex whereas overall size reduction and higher charge ratios promote transfection efficiency in vitro.

Keywords: transfection efficiency, liposome charge, liposome size

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]