Improvement of DNA transfection with cationic liposomes

Abstract

The increasing use of cationic liposomes as vectors for DNA transfection of eukaryotic cells is due to its high efficiency and reproducibility. After the interaction of the DNA cationic-liposome complexes (DNA-CLC) with the plasma membrane, the entry into the cells delivers the DNA-CLC to the endosome-lysosome pathway where some of the DNA-CLC are degraded. The non-degraded DNA that escapes to the cytoplasm, still has to transverse the nuclear membrane to be transcribed and then translated. To improve the efficiency of the whole process, we can manipulate the DNA (sequences, promoters, enhancers, nuclear localisation signals, etc), the DNA-CLC (lipids) or the plasmatic, endosomal and/or nuclear cellular membranes (ultrasound, electroporation, Ca++, pH of the endosomes, mitosis, fusogenic peptides, nuclear localisation signals, etc). Most of these methods have been generally used individually but in combination, may greatly improve the efficiency and reproducibility of in vitro transfection. While much of this work remains yet to be done and present results further explored, the application of these efforts is essential to the future development of new gene therapy strategies.

Induction of Type I IFN Is a Physiological Immune Reaction to Apoptotic Cell-Derived Membrane Microparticles

“…Endocytosis upon plasma membrane contact of "lipoplexes" and escape to the cytoplasm are hallmarks of DNA delivery by lipofection (59)(60)(61). Because MMP lipids could mediate comparable effects, we reasoned that MMP DNA, which we showed to be double stranded (Fig.…”

Efficient Immunization and Cross-Priming by Vaccine Adjuvants Containing TLR3 or TLR9 Agonists Complexed to Cationic Liposomes

“…The ability of cationic liposomes to potentiate activation of innate immunity by DNA is due to protection of the DNA from extracellular degradation and to enhanced entry of DNA into the endosomal compartment, where TLR9 is selectively expressed (19,22,23). The ability of cationic liposomes to promote entry into the cell via the endosomal compartment may also be important to activation by TLR3 agonists such as poly(I:C), inasmuch as TLR3 is also expressed primarily in the endosomal compartment (2)(3)(4)(5)24).…”

Transfection improvements of fish cell lines by using deacylated polyethylenimine of selected molecular weights

“…), seems to be due to its proton sponge effect [34]. The accepted explanation being that partially protonated polycations absorb protons increasingly during the later endocytic vesicle steps [47], thus causing their rupture and diminishing the degradation of their transported DNA during their endogenous cell pathways. However, as most transfection reagents, excess of concentration of PEI-LoTo could also cause excessive cell death [28] and thus reduce the expression efficiency as demonstrated for both EPC and RTG2 fish cell lines (Fig.…”

“…Polycations such as polylysine have been used for the introduction of foreign DNA into mammalian cells (grown at 37 C) long before the use of liposomal formulations [47]. However, progress was slow until the introduction of polyethylenimine (PEI) in 1995.…”

“…However, progress was slow until the introduction of polyethylenimine (PEI) in 1995. Polycations were scarcely used before to transfect fish cells which are grown at lower temperatures (15-28 C) [6,47].…”