An artificial virus-like nano carrier system: enhanced endosomal escape of nanoparticles via synergistic action of pH-sensitive fusogenic peptide derivatives

Abstract

We previously reported that transferrin (Tf)-modified liposomes (Tf-L) additionally modified with a cholesterylated pH-sensitive fusogenic peptide (Chol-GALA) can release an encapsulated aqueous phase marker to cytosol via endosomal membrane fusion. However, further obstacles need to be overcome to bring the Tf-L to the level of a viral-like gene delivery system. In this study, we developed a novel packaging method to encapsulate condensed plasmid DNA into PEgylated Tf-L (Tf-PEG-L) to form a core-shell-type nanoparticle. The most difficult challenge was to provide a mechanism of escape for the condensed core from endosome to cytosol in the presence of polyethylene glycol (PEG). We hypothesized that a membrane-introduced Chol-GALA and a PEgylated GALA would interact synergistically to induce membrane fusion between liposome and endosome. By simultaneously incorporating Chol-GALA into the membrane of Tf-PEG-L and GALA at tips of PEG chains, a condensed core was released into cytosol, and transfection activity increased 100-fold. We concluded that topological control was responsible for the synergistic effect of GALA derivatives introduced on Tf-PEG-L.

Topology of octaarginines (R8) or IRQ ligand on liposomes affects the contribution of macropinocytosis- and caveolae-mediated cellular uptake

“…Other studies showed that the attachment of Tf to the surface of liposomes with a PEG spacer (Tf-PEG-Lip) enhances cellular uptake efficiency and speed, compared with liposomes modified with Tf, albeit without the PEG spacer [14]. However, the effect of the topology of the ligand on the internalization mechanism is still unknown in arginine-rich peptides.…”

Efficient Short Interference RNA Delivery to Tumor Cells Using a Combination of Octaarginine, GALA and Tumor-Specific, Cleavable Polyethylene Glycol System

“…1, which was presumably due to an increase in endosomal escape by virtue of the function of GALA after the R8/GALA-MEND was taken up via endocytosis. 11,12) No further enhancement in activity was observed Ͼ2 mol%, because the ability of GALA to accelerate the endosomal escape might reach the limit in this formulation. Furthermore, in the case of 4 mol% of Chol-GALA, the aggregation occurred occasionally in R8/GALA-MEND formulation, which could have been caused by fusion between the lipid envelope of the MEND due to an excess amount of GALA.…”

Controlling and Monitoring Intracellular Delivery of Anticancer Polymer Nanomedicines

“…Cholesterol-GALA, which inserted in the liposome membrane, and PEGylated GALA, constituting the outer shell, were used to induce interaction and fusion between liposomes and endosome membranes. [23] Due to its negative charge, (9 of 26) 1700022 GALA is not able to bind electrostatically plasmid DNA or oligonucleotides. However, by replacing several of the negatively charged glutamic acid residues by positively charged lysine amino acids, Szoka and co-workers prepared a peptide that is referred to as KALA and which combines membrane-disrupting activity with the ability to form polyplexes with DNA and oligonucleotides.…”

“…[16,17] Targeting the human epidermal growth factor receptor-2 via the monoclonal antibody Trastuzumab has been reported to facilitate breast cancer cellular internalization of block copolymer micelle-based nanoparticles as well as polyplexes. [18,19] Upregulation of the transferrin receptor in pancreas, colon, lung, and bladder cancers was also exploited using transferrin-nanoparticle and linear polymer conjugates, [20][21][22][23] as well as transferrin-modified polyplexes. [24] Another example of a ligand used for prostate and lung cancer targeting is anisamide, which binds to the overexpressed sigma receptor.…”