Lipoplex size is a major determinant of in vitro lipofection efficiency

• Published in: Gene therapy Vol. 6; no. 4; pp. 651 - 659
• Main Authors: ROSS, P. C, HUI, S. W
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.04.1999
• Subjects: Animals; Anions; Biological and medical sciences; Biotechnology; CHO Cells; Cricetinae; Deoxyribonucleic acid; DNA; Efficiency; Fatty Acids, Monounsaturated; Fundamental and applied biological sciences. Psychology; Gene therapy; Gene transfer; Genetic Therapy - methods; Health. Pharmaceutical industry; Industrial applications and implications. Economical aspects; lipofection; Liposomes; Particle Size; Phosphatidylethanolamines; Polyanions; Quaternary Ammonium Compounds; Transfection; Transfection - methods; Biological fluid; Rodentia; Liposome; Molecular size; In vitro; Genetic transfer; Vertebrata; Mammalia; Cell line; Transfection; Serum; Gene therapy; Vector; Hamster
• ISSN: 0969-7128; 1476-5462
• DOI: 10.1038/sj.gt.3300863

The inhibition effect of serum on the transfection efficiency of cationic liposome-DNA complexes (lipoplexes) is a major obstacle to the application of this gene delivery vector both in vitro and in vivo. The size of the lipoplexes, as they are presented to targeted cells, is found to be the major determinant of their effectiveness in transfection. The transfection efficiency and the cell association and uptake of lipoplexes with CHO cells was found to increase with increasing lipoplex size. The influence on the transfection efficiency of lipoplexes by their cationic lipid:DNA ratios, types of liposomes, incubation time in polyanion containing media, and time of serum addition, are mediated mainly through size. Lipoplexes at a 2:1 charge ratio grow in size in media containing polyanions. The size growth may be arrested by adding serum to the incubation media. By using large lipoplexes, especially those made from multilamellar vesicles, the serum inhibition effect may be overcome.