Design of Smart Nano Device for Intracellular Targeting

To obtain an efficient delivery of macromolecule such as siRNA, a sophisticated design of vector is needed. It must be retained to the active uptake by reticuloendothelial system (RES) in the bloodstream and it can release its content inside the cellular target site. In this study, we attempted to design a vector which accommodates the needs. siRNA was encapsulated in the liposomes and its surface was shielded with polyethylene glycol (PEG) moiety to avoid recognizing by RES system. To facilitate cellular internalization, newly synthetizing peptide was attached to tip end of PEG moiety. As results, blood concentration of PEG‐modified liposomes was higher than that of unmodified PEG. Results by confocal laser scanning microscopy studies exhibited PEG‐coated nanodevice can escape from endosomes in both two types PEG used, shorter and longer one. However, prominent cytosolic release of siRNA was only shown by the use of shorter PEG type. These results were in line with gene silencing study in which shorter P...