PMC

Levels of IgG (A), IgG1 (B) and IgG2a (C) in the sera of experimental mice. Group A, B, C, D and E were intramuscularly injected with VRB2B3-LP, VRB2B3-CS, VRB2B3-PEG-O-CS-PEI, VRB2B3-PCL and VRB2B3-PCL-protamine, respectively; group F was the blank control group. (D) IgG1/IgG2a. No obvious change was found compared with that in blank control group, which indicated Th1/Th2 homeostasis during the whole experiment. The sign ($) indicates the challenge day with virulent EPEC E. coli. LP, liposomes; CS, chitosan; PEG-O-CS-PEI, polyethylene glycol-O-chitosan-polyethylenimine; PCL, polyamine cationic liposomes.

(A) DNA formulation with intercalating conjugates of functional peptides and polyamine. (B) Initially, the nanoformulation binds and enters cells via ApoE receptor-mediated endocytosis. The TAT peptide and biodegradation of polyamine then assist in the transfer of plasmid DNA across the cellular membrane. The next step of cytoplasmic translocation of DNA is performed by the nuclear localization signal peptide, and the plasmids enter nuclei through nuclear pores. Finally, active plasmids express anti-MRP4 shRNA that exits the nuclei and, in the complex with the RNA-induced silencing complex, suppress the activity of the MRP4 drug efflux transporter.
PEG: Polyethylene glycol