Optimizing cationic and neutral lipids for efficient gene delivery at high serum content

• Published in: The journal of gene medicine Vol. 16; no. 3-4; pp. 84 - 96
• Main Authors: Chan, Chia-Ling, Ewert, Kai K., Majzoub, Ramsey N., Hwu, Yeu-Kuang, Liang, Keng S., Leal, Cecília, Safinya, Cyrus R.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.03.2014; Wiley Periodicals Inc
• Subjects: Benzamides - chemistry; cationic liposomes; Cations - chemistry; Cell Line, Tumor; DNA - genetics; Escherichia coli - genetics; Fatty Acids, Monounsaturated - chemistry; gene delivery; Gene therapy; Gene Transfer Techniques; Genetic Therapy - methods; glycerol monooleate; Humans; Lipids - chemistry; Liposomes - chemistry; multivalent cationic lipid; Plasmids - genetics; Quaternary Ammonium Compounds - chemistry; serum; Serum - chemistry; Spermine - analogs & derivatives; Spermine - chemistry; Transfection; gene delivery; multivalent cationic lipid; serum; glycerol monooleate; cationic liposomes
• ISSN: 1099-498X; 1521-2254
• DOI: 10.1002/jgm.2762

BackgroundCationic liposome (CL)–DNA complexes are promising gene delivery vectors with potential application in gene therapy. A key challenge in creating CL–DNA complexes for application is that their transfection efficiency (TE) is adversely affected by serum. In particular, little is known about the effects of a high serum content on TE, even though this may provide design guidelines for application in vivo. MethodsWe prepared CL–DNA complexes in which we varied the neutral lipid [1,2‐dioleoyl‐sn‐glycerophosphatidylcholine, glycerol‐monooleate (GMO), cholesterol], the headgroup charge and chemical structure of the cationic lipid, and the ratio of neutral to cationic lipid; we then measured the TE of these complexes as a function of serum content and assessed their cytotoxicity. We tested selected formulations in two human cancer cell lines (M21/melanoma and PC‐3/prostate cancer). ResultsIn the absence of serum, all CL–DNA complexes of custom‐synthesized multivalent lipids show high TE. Certain combinations of multivalent lipids and neutral lipids, such as MVL5(5+)/GMO–DNA complexes or complexes based on the dendritic‐headgroup lipid TMVLG3(8+) exhibited high TE both in the absence and presence of serum. Although their TE still dropped to a small extent in the presence of serum, it reached or surpassed that of benchmark commercial transfection reagents, particularly at a high serum content. ConclusionsTwo‐component vectors (one multivalent cationic lipid and one neutral lipid) can rival or surpass benchmark reagents at low and high serum contents (up to 50%, v/v). We propose guidelines for optimizing the serum resistance of CL–DNA complexes based on a given cationic lipid. Copyright © 2014 John Wiley & Sons, Ltd.