Synthesis and characterization of NIR light-responsive LbL nanocapsules

In this paper, near-infrared (NIR) light responsive polyelectrolyte multilayer capsules (PE/Au NRs@Dox) were successfully synthesized by layer-by-layer techniques. Gold nanorods with aspect ratio of 3.9, and a longitudinal absorbance peak at 765nm were prepared using seed-mediated method which used the cationic surfactant cetyltrimethylammonium bromide (CTAB) as a soft template and structure-guiding agent. Sequential layers of polyanions (sodium polystyrene sulfonate (PSS)) and polycations (poly diallyldimethylammonium chloride (PDADMAC)) were followed by adsorption of three BSA/PSS bilayers. The doxorubicin (Dox) is loaded by the electrostatic interaction. The release of Dox from the swelling polyelectrolyte complex PE/Au NRs@Dox was induced by the heat generated from gold nanorods under laser irradiation. Moreover, the in vitro cytotoxicity of PE/Au NRs@Dox and the doxorubicin release from the composites were investigated.