title: Gold nanorods for target selective SPECT/CT imaging and photothermal therapy in vivo.
abstract: The development of theranostic agents with high detection sensitivity and antitumor efficacy at low concentration is a challenging task for target selective imaging and therapy of cancers. In this study, folate-conjugated and radioactive-iodine-labeled gold nanorods (GNRs) were designed and synthesized for target selective SPECT/CT imaging and subsequent thermal ablation of folate-receptor-overexpressing cancers. Both (ortho-pyridyl) disulfide-poly(ethylene glycol)-folate and a short peptide, H(2)N-Tyr-Asn-Asn-Leu-Ala-Cys-OH, were conjugated on the surface of the GNRs through thiol chemistry. The tyrosine in the peptide sequence was introduced for radioactive-iodine labeling through an iodine-tyrosine interaction. The labeling efficiency of radioactive iodine was more than 99%. Radiochemical stability tests on iodine-125-labeled GNRs in human serum showed that 91% of the iodine-125 remained intact on the GNRs after incubation for 24 h. In vitro and in vivo results in this study confirmed the potential utility of folate-conjugated and iodine-125-labeled GNRs as smart theranostic agents. This type of platform may also be useful for the targeted SPECT/CT imaging and photothermal therapy of inflammatory diseases such as atherosclerosis and arthritis, in which folate-receptor-overexpressing macrophages play pivotal roles.
authors.affiliation: Molecular Imaging & Therapy Branch, Division of Convergence Technology, National Cancer Center, Republic of Korea.
authors.forename: Boseung
authors.initials: B
authors.lastname: Jang
authors.forename: Seonhwa
authors.initials: S
authors.lastname: Park
authors.forename: Se Hun
authors.initials: SH
authors.lastname: Kang
authors.forename: Joa Kyum
authors.initials: JK
authors.lastname: Kim
authors.forename: Seok-Ki
authors.initials: SK
authors.lastname: Kim
authors.forename: In-Hoo
authors.initials: IH
authors.lastname: Kim
authors.forename: Yongdoo
authors.initials: Y
authors.lastname: Choi