Plasmonic microgels of Au nanorods: Self-assembly and applications in chemophotothermo-synergistic cancer therapy.

Plasmonic microgels (PMgels) of the self-assembled gold nanorods (Au NRs) with side-by-side piles in ionic liquid microgels were prepared. Transmission electron microscopy (TEM) images revealed unique self-growth and self-arrangement of Au NRs in the microgel systems. The fabrication of PMgels occurs through co-assembling Au NRs and an ionic liquid microgel system, therefore differs from the fabrication of conventional plasmonic hybrid nanocomposites. These PMgels showed strong absorption in the near-infrared window and enhanced photothermal conversion efficiency, up to 52.8%, compared to the Au NRs (22%) as a result of the ordering and dense packing of Au NRs in the microgels. When the PMgels were exposed to a near-IR laser, the doxorubicin hydrochloride (Dox) released from PMgels and the resulting thermal effect can immensely inhibit tumor growth both in vitro and in vivo. The tests demonstrated that no tumor metastasis occurred. This platform of the PMgels with the laser-controlled delivery system could provide chemo-photothermal synergistic therapy for a wide spectrum of diseases.