Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.
Nanoscale. 2012 Dec 21;4(24):7712-9. doi: 10.1039/c2nr32196c. Epub 2012 Nov 6.
Gold nanorods with three different aspect ratios were prepared and their dual capabilities for two-photon imaging and two-photon photodynamic therapy have been demonstrated. These gold nanorods exhibit large two-photon absorption action cross-sections, about two orders of magnitude larger than small organic molecules, which makes them suitable for two-photon imaging. They can also effectively generate singlet oxygen under two-photon excitation, significantly higher than traditional photosensitizers such as Rose Bengal and Indocyanine Green. Such high singlet oxygen generation capability under two-photon excitation was ascribed to their large two-photon absorption cross-sections. Polyvinylpyrrolidone (PVP) coated gold nanorods displayed excellent biocompatibility and high cellular uptake efficiency. The two-photon photodynamic therapy effect and two-photon fluorescence imaging properties of PVP coated gold nanorods have been successfully demonstrated on HeLa cells in vitro using fluorescence microscopy and indirect XTT assay method. These gold nanorods thus hold great promise for imaging guided two-photon photodynamic therapy for the treatment of various malignant tumors.
制备了三种不同纵横比的金纳米棒，并证明了它们在双光子成像和双光子光动力治疗方面的双重功能。这些金纳米棒具有较大的双光子吸收作用截面，比小分子约大两个数量级，这使得它们适合双光子成像。它们在双光子激发下也能有效产生单线态氧，明显高于传统的光敏剂如 Rose Bengal 和吲哚菁绿。这种在双光子激发下产生高单线态氧的能力归因于它们较大的双光子吸收截面。聚乙烯吡咯烷酮（PVP）包覆的金纳米棒表现出优异的生物相容性和高细胞摄取效率。通过荧光显微镜和间接 XTT 测定法，成功地在体外 HeLa 细胞上证明了 PVP 包覆的金纳米棒的双光子光动力治疗效果和双光子荧光成像特性。因此，这些金纳米棒有望用于各种恶性肿瘤的成像引导双光子光动力治疗。
