Active accumulation of gold nanorods in tumor in response to near-infrared laser irradiation

Atsushi Shiotani, Yasuyuki Akiyama, Takahito Kawano, Yasuro Niidome, Takeshi Mori, Yoshiki Katayama, Takuro Niidome

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    42 Citations (Scopus)


    Gold nanorods, rod-shaped gold nanoparticles, have strong absorbance in the near-infrared region, and the absorbed light energy can be converted to heat, the so-called photothermal effect. The gold nanorods were coated with thermoresponsive polymers, which have different phase transition temperatures that were controlled by adding comonomers, N,N-dimethylacrylamide (DMAA) or acrylamide (AAm) to N-isopropylacrylamide (NIPAM). The phase transition temperatures of poly(NIPAM-DMAA) and poly(NIPAM-AAm)-coated gold nanorods were 38 and 41 °C, respectively, while polyNIPAM-coated gold nanorods showed phase transition at 34 °C. Irradiation of the coated gold nanorods using the near-infrared laser induced a decrease in their sizes due to a phase transition of the polymer layers. Poly(NIPAM-AAm)-coated gold nanorods stably circulated in the blood flow without a phase transition after intravenous injection. Irradiation of near-infrared light at a tumor after the injection resulted in the gold specifically accumulating in the tumor. This novel accumulation technique which combines a thermoresponsive polymer and the photothermal effect of the gold nanorods should be a powerful tool for targeted delivery in response to light irradiation.

    Original languageEnglish
    Pages (from-to)2049-2054
    Number of pages6
    JournalBioconjugate Chemistry
    Issue number11
    Publication statusPublished - Nov 17 2010

    All Science Journal Classification (ASJC) codes

    • Biotechnology
    • Bioengineering
    • Biomedical Engineering
    • Pharmacology
    • Pharmaceutical Science
    • Organic Chemistry


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