In this investigation,
chitosan-
histidine-
cysteine (CHC) was engineered for oral delivery of
Survivin short hairpin RNA (
shRNA)-expressing plasmid
DNA (shSur-pDNA) to promote
hepatoma regression through integrating the advantages of
histidine and
cysteine to conquer serial cellular and systemic barriers. CHC could effectively encapsulate shSur-pDNA to form compact nanocomplexes (NC) at adequate weight ratios. Sequential modification with
histidine and
cysteine conferred CHC NC with the beneficial attributes for
shRNA delivery including improved stability, facilitated internalization, promoted endosomal escape, increased nuclear localization, and GSH-responsive release, which contributed to their superior performance in terms of apoptosis promotion, proliferation inhibition, and
Survivin down-regulation of
tumor cells. More importantly, in
hepatoma-bearing mice, orally delivered CHC NC overweighed
chitosan counterparts with respect to suppressed
Survivin expression, retarded
tumor growth, and prolonged surviving time, owing to their above-mentioned merits in combination with enhanced intestinal permeation. Especially, rapid intracellular release of CHC NC with lower molecular weight of 30 kDa (CHC30 NC) might be responsible for the most satisfactory antitumor efficacy with
tumor inhibition ratio (TIR) of 92.5%, which rendered CHC30 NC a promising vehicle for oral delivery of
shRNA. This investigation would shed light on the deliberate design of oral
shRNA delivery vehicles to mediate effective antitumor efficacy.