Efficiency of cationic rosette nanotubes for siRNA delivery

Cationic rosette nanotubes (RNTs) were generated by functionalization of self-complementary twin guanine-cytosine (G 27C) motifs with up to 15 L-lysine residues (Kn.T, n = 1-15). siRNA binding capacity was determined by gel retardation assay on agarose gel. Up to K5.T, siRNA complexation was a function of oligolysine-chain length and mole ratio of Kn.T. At higher Kn.T, local cationic density employed by supramolecular assembly emerged as a contributor to siRNA complexation. We have shown that no effective siRNA binding was achieved with equivalent mole ratios of corresponding oligolysine peptides (not conjugated to the G 27C motif). With K12.T, siRNA complexation gave spherical structures in the range of 200 nm, which was internalized and retained by human cell lines without noticeable cytotoxicity. In this report, we demonstrate for the first time the capacity of the RNTs as siRNA carriers that can be tailored to achieve maximum siRNA loading efficiency without carrier-associated cell toxicity. We anticipate these cationic RNTs to be effective in the delivery of biologically-functional siRNA. \ua9 2011 Materials Research Society.Peer reviewed: YesNRC publication: Ye