Polyspermine imidazole-4,5-imine, a chemically dynamic and biologically responsive carrier system for intracellular delivery of siRNA.
ABSTRACT Silence please! Polyspermine imidazole-4,5-imine (blue lines) was formed by condensing spermine with bisformaldehyde imidazole through a pH-responsive linkage. This polymer was used to condense siRNAs into nanoparticles and studied for delivery into cells and release from endosomes. Cellular and in vivo assays indicated that this siRNA carrier was efficient in silencing target genes with negligible cytotoxicity.