SiRNA-loaded multi-shell nanoparticles incorporated into a multilayered film as a reservoir for gene silencing.

In this study, we presented a new type of coating based on polyelectrolyte multilayers containing sequentially adsorbed active shRNA calcium phosphate nanoparticles for locally defined and temporarily variable gene silencing. Therefore, we investigated multi-shell calcium phosphate-shRNA nanoparticles embedded into a polyelectrolyte multilayer for gene silencing. As model system, we synthesized triple-shell calcium phosphate-shRNA nanoparticles (NP) and prepared polyelectrolyte multilayers films made of nanoparticles and poly-(L-lysine) (PLL). The biological activities of these polyelectrolyte multilayers films were tested by the production of osteopontin and osteocalcin in the human osteoblasts (HOb) which were cultivated on the PEM films. This new strategy can be used to efficiently control the bone formation and could be applicable in tissue engineering. Copyright 2010 Elsevier Ltd. All rights reserved.