Targeted cytosolic delivery of hydrogel nanoparticles into HepG2 cells through engineered Sendai viral envelopes

Abstract

Hydrogel nanoparticles of cross-linked polyvinylpyrrolidone (PVP-NP) (35-50 nm in diameter) containing fluoresceinated dextran (FITC-Dx) were encapsulated in reconstituted Sendai viral envelopes containing only the fusion (F) protien (F- virosomes). Incubtion of these loaded F- virosmes with human hepatoblastoma cells (HepG2) in culture cytoplasm, as inferred froom the ability of cells tointernalize FITC-Dx loaded PVP-NP(PVP-NP) in the presence of azide (an inhibitor of the endocytotic process). Introduction of PVP-NP into the HelpG2 cells wasw assured by selctive accumulation of FITC fluorescence in the cytosolic compartment. The structural integrity of the internalzed PVP-NP was also confirmed by fluorescence microscopy and ultracentrifugation analysis. The potential usefulness of PVP-NP -mediated cytosolic release of water soluble drugs boyh in vitro and in vivo has been established for the first time.