New strategy for transfection: mixtures of medium-chain and long-chain cationic lipids synergistically enhance transfection

Abstract

To date, the primary approach to improve the transfection properties of cationic lipids has been the synthesis of new kinds of cationic amphipaths or the inclusion of noncationic helper lipids. Here, it is reported that an alternative approach can be unusually effective, namely, the combination of two cationic lipid derivatives having the same head group but tails of different chain lengths. Particularly efficient was the combination of dilauroyl (12 carbon chain) and dioleoyl (18 carbon chain) homologues of O-ethylphosphatidylcholine.This mixture transfected DNA into human umbilical artery endothelial cells (HUAEC) more than 30-fold more efficiently than either compound separately. A unique advantage of this kind of combination agent is that transfection can be optimized either in the presence or absence of serum by adjusting the component ratio.

Higly fusogenic cationic liposomes transiently permeabilize the plasma membrane of HeLa cells

“…However, fusion with the endosomal membrane followed by its disruption is thought to be a key event enabling lipoplex cargo release from the endosomal compartment [2,[7][8][9][10][11]. Short-chained lipids are more fusogenic than long-chained ones, and liposomes composed of cationic lipids of different acyl chain lengths fuse more easily than those made up of lipids with identical acyl chains [12]. DiC14-amidine, a shortchained cationic lipid, has been reported to posses a high level of transfection activity even in the absence of helper lipids in vitro and in vivo [13,14].…”

An intracellular lamellar–nonlamellar phase transition rationalizes the superior performance of some cationic lipid transfection agents

“…Understanding the mechanism of lipid-mediated DNA delivery (lipofection) is essential for the successful application and rational design and synthesis of novel cationic lipoid compounds for enhanced gene delivery. Although considerable improvement in the transfection properties of cationic lipoids has come from the synthesis of new kinds of cationic amphiphiles or from the inclusion of noncationic helper lipids, an effective alternative strategy was recently described: The combination of two cationic lipid derivatives having the same headgroup but different hydrocarbon chains can synergistically enhance transfection (2). For example, the optimal combination of the long chain͞medium chain lipoids, dioleoyl-and dilauroyl-ethylphosphatidylcholines, delivered DNA into cells more than 30 times more efficiently than either compound separately (2).…”

Delivery into cells: lessons learned from plant and bacterial toxins

“…45 Such agents include virus, cationic polymers, and lysosomotropic agents such as chloroquine. 45,46 In the case of adenovirus and peptides derived from Heamophilus influenza hemagglutinin from influenza virus, low pH-induced effects on the virus or the virus peptides are involved in the disruption of endosomes and increased DNA transfer to the cytosol. This is in contrast to diphtheria toxin that does not seem to disrupt endosomes, since it does not mediate release of gelonin and intoxication of cells that are resistent to diphtheria toxin due to a mutation of elongation factor 2 (our own unpublished data).…”