A simple approach to obtain hybrid Au-loaded polymeric nanoparticles with a tunable metal load

摘要

A new strategy to nanoengineer multi-functional polymer–metal hybrid nanostructures is reported. Byusing this protocol the hurdles of most of the current developments concerning covalent and noncovalentattachment of polymers to preformed inorganic nanoparticles (NPs) are overcome. The strategyis based on the in situ reduction of metal precursors using the polymeric nanoparticle as a nanoreactor.Gold nanoparticles and poly(DL-lactic-co-glycolic acid), PLGA, are located in the core and shell, respectively.This novel technique enables the production of PLGA NPs smaller than 200 nm that bear either asingle encapsulated Au NP or several smaller NPs with tunable sizes and a 100% loading efficiency. In situreduction of Au ions inside the polymeric NPs was achieved on demand by using heat to activate thereductive effect of citrate ions. In addition, we show that the loading of the resulting Au NPs inside thePLGA NPs is highly dependent on the surfactant used. Electron microscopy, laser irradiation, UV-Vis andfluorescence spectroscopy characterization techniques confirm the location of Au nanoparticles. Thesepromising results indicate that these hybrid nanomaterials could be used in theranostic applications or ascontrast agents in dark-field imaging and computed tomography