We rationally formulated a nucleic acid nanovector platform utilizing endogenous molecules in the following steps: nucleic acids are initially packed by a multifunctional peptide and a cationic liposome to form positively charged ternary complexes through electrostatic interaction; then the ternary complexes were coated with hyaluronic acid (HA) to form negatively charged quaternary nanocomplexes (Q-complexes). Among the components of Q-complexes, the multifunctional peptide was composed of a poly-16-arginine (R16) and a hepatic tumor-targeted cell penetrating peptide (KRPTMRFRYTWNPMK); the cationic lipid component included DOTAP and fusogenic lipid DOPE; the HA component shielded the cationic ternary complexes and actively targeted the CD44 overexpressed on the surface of tumor cells. Q-complexes have showed a relatively high stability in the medium, and HA component partially separated from the nanocomplexes after the Q-complexes bound to the cancer cells. The Q-complexes showed significantly enhanced nucleic acid delivery activity than the corresponding quaternary complexes containing R16 and nonvisible cytotoxicity in SCMM-7721 cells. In vivo, a selected Q-complex HLP1R specifically targeted and entered tumor cells without affecting normal tissues. Furthermore, HLP1R wrapped survivin siRNA efficiently and silenced the targeting gene in the liver orthotropic transplantation tumor models and showed nontoxic in vivo. This study reveals that Q-complexes are reasonable and feasible gene therapeutic carriers.
Keywords: cationic lipid component; hepatic carcinoma selective delivery system; hyaluronic acid; modular design; multifunctional peptide.