Development of Supramolecular Pseudo-Block Conjugates Based on Star-Shaped Polycation for DNA Delivery

摘要

Supramolecular assembly provides a new strategy for designing various gene carriers for deoxyribonucleic acid (DNA) delivery. In this work, supramolecular pseudo-block conjugates based on star-shaped polycation are developed as novel nonviral gene vector. First, cyclodextrin (CD) is selected as core and grafted with low molecular weight polyethylenimine (PEI1800) as arms to obtain high molecular weight star-shaped polycation CD-PEI8 (SCP). Then, azobenzene (Az) modified poly(ethylene glycol) is synthesized and named as azobenzene modified poly(ethylene glycol) (Az-PEG). Subsequently, the supramolecular pseudo-block conjugates are prepared via host-guest interaction between CD and Az. The result suggests that SCP/Az-PEG condenses DNA into spherical nanoparticles with sizes of around 150 nm. The in vitro experiment shows that the cell viability of DNA/SCP/Az-PEG polyplexes is significantly improved compared with that of PEI25k/DNA polyplexes. The PEGylation does not decrease the cellular uptake efficiency and transfection efficiency. Furthermore, the cellular trafficking shows that PEGylation does not significantly influence nuclear entry. The star-shaped architecture of polycation plays an important role in gene delivery.