Hierarchical gold/copolymer nanostructures as hydrophobic nanotanks for drug encapsulation

Various nanoparticles are used to fabricate innovative systems for drug encapsulation and cancer therapy. In this paper, the hierarchical core-shell nanostructures composed of gold nanoparticles and poly(dimethylsiloxane)-poly(ethylene glycol) (PDMS-PEG) block copolymers are fabricated via a hydrosilylation reaction. The obtained gold/copolymer nanocomposites display a desired amphiphilic property and can be well-dispersed in water when the PEG blocks are long enough. The hydrophobic drug hypocrellin B (HB) can be encapsulated into these water-dispersible nanocomposites based on the hydrophobic-hydrophobic interaction between HB molecules and PDMS segments. The gold/copolymer nanocomposites loaded with HB show a rational anticancer ability in the photodynamic therapy although the gold/copolymer nanocomposites without drug also have a little cytotoxicity. Such hierarchically structured core-shell nanocomposites can be considered as water-dispersible nanotanks for hydrophobic drugs in the development of multifunctional biodelivery systems.