Multifunctional metal rattle-type nanocarriers for MRI-guided photothermal cancer therapy

In the past decade, numerous species of nanomaterials have been developed for biomedical application, especially cancer therapy. Realizing visualized therapy is highly promising now because of the potential of accurate, localized treatment. In this work, we first synthesized metal nanorattles (MNRs), which utilized porous gold shells to carry multiple MR imaging contrast agents, superparamagnetic iron oxide nanoparticles (SPIONs), inside. A fragile wormpore-like silica layer was manipulated to encapsulate 8 nm oleylamine SPIONs and mediate the in situ growth of porous gold shell, and it was finally etched by alkaline solution to obtain the rattle-type nanostructure. As shown in the results, this nanostructure with unique morphology could absorb near-infrared light, convert to heat to kill cells, and inhibit tumor growth. As a carrier for multiple SPIONs, it also revealed good function for T2-weighted MR imaging in tumor site. Moreover, the rest of the inner space of the gold shell could also introduce potential ability as nanocarriers for other cargos such as chemotherapeutic drugs, which is still under investigation. This metal rattle-type nanocarrier may pave the way for novel platforms for cancer therapy in the future.