Disulfide-Bridged Cleavable PEGylation of Poly- l -Lysine for SiRNA Delivery

Engineered PEG-cleavable catiomers based on poly-L-lysine have been developed as nonviral gene vectors, which have been found to be one of important methods to balance "PEG dilemma." In this protocol, we aim at the standardization of the method and procedure of PEG-cleavable catiomers. Major steps including ring-opening polymerization (ROP) of e-benzyloxycarbonyl-L-lysine N-carboxyanhydride (zLL-NCA) monomers to yield PEG-cleavable polylysine, examination on bio-stability and bio-efficacy of its gene complexes are described.