Plasmonic gold nanoparticles present extraordinary potential for near-infrared photothermal and triggered-therapeutic release treatments of solid tumors. In this study, we create a multifunctional nanocarrier in which PEG-coated gold nanorods are grouped into natural cell membrane vesicles (CM) from lung cancer (A549) cells and loaded with β-lapachone (CM-β-Lap-PEG-AuNRs). β-Lapachone (β-Lap) is an anticancer agent activated by the enzyme NADP­(H):quinine oxidoreductase (NQO1), commonly found at higher levels in cancer cells. The irradiation with near-infrared (NIR) laser leads to disruption of the vesicles and release of the PEG-AuNRs and β-Lap. The system presents an enhanced in vitro cytotoxicity against A549 cancer cells, which can be attributed to the specific cytotoxicity of β-Lap combined with heat generated by laser irradiation of the AuNRs. In agreement, in vivo treatment with CM-β-Lap-PEG-AuNRs and irradiation shows a histopathological recovery from nonmuscle invasive bladder cancer of most of the animals with only one cycle of application and irradiation. Such multifunctional platform is a promissing candidate for improved activated drug release and phototherapy.

The development of new systems for diagnostic and therapeutic applications is a topic of intense and growing interest. The unique optical and electronic properties exhibited by gold-based nanomaterials have proved to be valuable for a wide range of biomedical applications. Recently, great attention has been given to rod-shaped gold nanomaterials, especially because of their electronic absorption band in the near infrared region, where maximum radiation penetration through tissue occurs. This feature has allowed the use of gold nanorods for in vivo imaging, with different techniques, and photothermal therapy. Furthermore, gold nanorods can be functionalized with a wide variety of biomolecules for cancer cell targeting. Moreover, their versatility and unique properties have generated much enthusiasm in medicine. The present review aims to show the recent advances in the synthesis and applications of gold nanorods in medical areas.

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