Facile approach to synthesize gold nanorod@polyacrylic acid/ calcium phosphate yolk–shell nanoparticles for dual-mode imaging and pH/NIR-responsive drug delivery

Abstract

A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate (AuNR@-PAA/CaP) yolk–shell nanoparticles (NPs) composed with a PAA/CaP shell and an AuNR yolk is reported. The as-obtained AuNR@PAA/CaP yolk–shell NPs possess ultra-high doxorubicin (DOX) loading capability (1 mg DOX/ mg NPs), superior photothermal conversion property (26%) and pH/near-infrared (NIR) dual-responsive drug delivery performance. The released DOX continuously increased due to the damage of the CaP shell at low pH values. When the DOX-loaded AuNR@PAA/CaP yolk–shell NPs were exposed to NIR irradiation, a burst-like drug release occurs owing to the heat produced by the AuNRs. Furthermore, AuNR@PAA/CaP yolk–shell NPs are successfully employed for synergic dual-mode X-ray computed tomography/photoacoustic imaging and chemo-photother-mal cancer therapy. Therefore, this work brings new insights for the synthesis of multifunctional nanomaterials and extends theranostic applications.