SiRNAs molecules transfection efficiency

As an alternative to cationic lipids, the potential of anionic lipids for DNA delivery has been investigated. Because of their negative charge, DNA or siRNA molecules are very inefficiently entrapped by anionic lipids alone. In the presence of cations such as K+, Na+, or Ca2+, the complex formation of such anionic lipids and nucleic acids can be enhanced. The resulting ternary complexes of DNA, anionic lipids, and divalent calcium ions have been reported to transfect mammalian cell lines efficiently [33]. Despite this, there has only been limited progress with these anionic lipid DNA delivery systems, a fact that may be attributed, in part, to the poor association between DNA molecules and anionic lipids, caused by electrostatic repulsion between these negatively charged species. 

Singh, B., Choi, Y.J., Park, I.K., Akaike, T, Cho, C.S., 2014. Chemical modification of chi-tosan with pH-sensitive molecules and specific ligands for efficient DNA transfection and siRNA silencing. J. Nanosci. Nanotechnol. 14 (1), 564—576. 

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