Rattle-Type Gold Nanorods/Porous-SiO2 Nanocomposites as Near-Infrared Light-Activated Drug Delivery Systems for Cancer Combined Chemo–Photothermal Therapy

Rattle-type nanostructures with movable cores, porous shells, and hollow interiors have become attractive nanoplatforms in the field of nanomedicine, especially for targeted and stimuli-responsive drug delivery. In this work, rattle-type gold nanorods@void@porous-SiO2 (GVPS) nanocomposites were fabricated facilely using the surface-protecting etching method and exhibited high photothermal conversion efficiency. Taking advantage of the porous shell and hollow interior, the nanocomposites have abundant space for drug loading and successfully improved the drug loading capacity up to ∼19.6%. To construct a multifunctional drug delivery system, GVPS was further functionalized with polyethylene glycol (PEG) and cyclic RGD peptides to improve biocompatibility as well as selectivity toward the targeted cancer cells. Besides, to achieve precise regulation and near-infrared laser activation of the drug release, a phase-changing material, 1-tetradecanol (1-TD, Tm: 39 °C), was employed as gatekeepers in this system. After incubation with an αVβ3 integrin receptor-overexpressed cell line, the as-prepared GVPSPR-DOX/TD nanocomposites exhibited great performances in combined photothermal therapy and chemotherapy. It is worth noting that the combined therapy showed superior efficiency in cancer cell killing to chemotherapy or photothermal therapy alone.