Preventing Plasmon Coupling between Gold Nanorods Improves the Sensitivity of Photoacoustic Detection of Labeled Stem Cells in Vivo

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• 作者：Joan Comenge ; Oihane Fragueiro ; Jack Sharkey ; Arthur Taylor ; Marie Held ; Neal C. Burton ; Brian Kevin Park ; Bettina Wilm ; Patricia Murray ; Mathias Brust ; Raphaël Lévy
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：July 26, 2016
• 年：2016
• 卷：10
• 期：7
• 页码：7106-7116
• 全文大小：749K
• 年卷期：0
• ISSN：1936-086X

文摘

Gold nanorods are excellent contrast agents for imaging technologies which rely on near-infrared absorption such as photoacoustic imaging. For cell tracking applications, the cells of interest are labeled with the contrast agent prior to injection. However, after uptake into cells by endocytosis, the confinement and high concentration in endosomes leads to plasmon band broadening and reduced absorbance. This would limit the potential of multispectral optoacoustic tomography in terms of spectral processing and, consequently, sensitivity. Here, we show that steric hindrance provided by silica coating of the nanorods leads to the preservation of their spectral properties and improved photoacoustic sensitivity. This strategy allowed the detection and monitoring of as few as 2 × 10⁴ mesenchymal stem cells in mice over a period of 15 days with a high spatial resolution. Importantly, the silica-coated nanorods did not affect the viability or differentiation potential of the transplanted mesenchymal stem cells.