Exceptionally High Payload of Doxorubicin in Hollow Gold Nanospheres for Near-Infrared Light-Triggered Drug Release

TLDR

The study introduces hollow gold nanospheres (~40 nm) engineered to simultaneously ablate cancer cells and release doxorubicin when irradiated with near‑infrared light. Near‑infrared laser irradiation induces photothermal heating of the nanospheres, triggering rapid, pH‑dependent release of doxorubicin from both their inner and outer surfaces. The nanospheres achieve up to 63 % doxorubicin loading, release more drug at lower pH, and produce markedly higher killing of MDA‑MB‑231 cells upon irradiation due to combined photothermal and chemotherapeutic effects.

Abstract

We report dual-functional hollow gold nanospheres (HAuNS, ∼40-nm diameter) capable of mediating both photothermal ablation of cancer cells and drug release upon near-infrared (NIR) light irradiation. As high as 63% DOX by weight (∼1.7 μg DOX/μg Au) could be loaded to polyethylene glycol (PEG)-coated HAuNS since DOX was coated to both the outer and the inner surfaces of HAuNS. Irradiation with NIR laser induced photothermal conversion, which triggered rapid DOX release from DOX-loaded HAuNS. The release of DOX was also pH-dependent, with more DOX released in aqueous solution at lower pH. Significantly greater cell killing was observed when MDA-MB-231 cells incubated with DOX-loaded HAuNS were irradiated with NIR light, attributable to both HAuNS-mediated photothermal ablation and cytotoxicity of released free DOX.