title: [Theragnostic approaches using gold nanorods and near infrared light].
abstract: Gold nanoparticles have unique optical properties such as surface-plasmon and photothermal effects. Such properties have resulted in gold nanoparticles having several clinical applications. Gold nanorods (which are rod-shaped gold nanoparticles) show a surface plasmon band in the near-infrared region. They have therefore been proposed as contrast agents for bioimaging, or as heating devices for photothermal therapy. Polyethylene glycol-modified gold nanorods systemically administrated into mice can be detected with integrating sphere, and the stability of the gold nanorods in blood flow evaluated. After intravenous injection of gold nanorods followed by near-infrared laser irradiation, significant tumor damage triggered by the photothermal effect was observed. To deliver gold nanorods to the target tissue, thermosensitive polymer gel-coated gold nanorods were prepared. After intravenous injection of the gel-modified gold nanorods and irradiation of the tumor, a larger amount of gold was detected in the irradiated tumor than in the non-irradiated tumor. This effect is due to the hydrophobic interaction between the cellular membrane or the extracellular matrix and the gel surfaces induced by the photothermal effect. Furthermore, the photothermal effect enhanced the permeability of the stratum corneum of the skin. As a result of treatment of the skin with ovalbumin and gold nanorods followed by near-infrared light irradiation, a significant amount of protein was detected in the skin. The gold nanorods therefore showed several functions as a photothermal nanodevice for bioimaging, thermal therapy, and a drug delivery system.
authors.affiliation: Faculty of Engineering, Kyushu University, Fukuoka, Japan. niidome.takuro.655@m.kyushu-u.ac.jp
authors.forename: Takuro
authors.initials: T
authors.lastname: Niidome
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shiotani
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Akira
authors.initials: A
authors.lastname: Ohga
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nose
authors.forename: Dakrong
authors.initials: D
authors.lastname: Pissuwan
authors.forename: Yasuro
authors.initials: Y
authors.lastname: Niidome
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D003287:Contrast Media; D016503:Drug Delivery Systems; D006046:Gold / Q000627:therapeutic use*; D006801:Humans; D007259:Infrared Rays; D017075:Laser Coagulation; D051379:Mice; D043942:Nanotubes; D009369:Neoplasms / Q000628:therapy; D011092:Polyethylene Glycols
chemical_list: D001672:Biocompatible Materials; D003287:Contrast Media; D011092:Polyethylene Glycols; D006046:Gold