Preventing Plasmon Coupling between Gold Nanorods Improves the Sensitivity of Photoacoustic Detection of Labeled Stem Cells in Vivo.
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 × 10(4) 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.
Institute of Integrative Biology, University of Liverpool , Liverpool L69 7ZB, United Kingdom.
Joan
J
Comenge
Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom.
Oihane
O
Fragueiro
Institute of Translational Medicine, University of Liverpool , Liverpool L69 3BX, United Kingdom.
Jack
J
Sharkey
Institute of Translational Medicine, University of Liverpool , Liverpool L69 3BX, United Kingdom.
Arthur
A
Taylor
Institute of Integrative Biology, University of Liverpool , Liverpool L69 7ZB, United Kingdom.
Marie
M
Held
iThera Medical GmbH , Zielstattstrasse 13, 81379 Munich, Germany.
Neal C
NC
Burton
Institute of Translational Medicine, University of Liverpool , Liverpool L69 3BX, United Kingdom.
Brian Kevin
BK
Park
Institute of Translational Medicine, University of Liverpool , Liverpool L69 3BX, United Kingdom.
Bettina
B
Wilm
Institute of Translational Medicine, University of Liverpool , Liverpool L69 3BX, United Kingdom.
Patricia
P
Murray
Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom.
Mathias
M
Brust
Institute of Integrative Biology, University of Liverpool , Liverpool L69 7ZB, United Kingdom.
Raphaël
R
Lévy
D000818:Animals; D006046:Gold; D051379:Mice; D043942:Nanotubes; D061088:Photoacoustic Techniques; D012822:Silicon Dioxide; D013057:Spectrum Analysis; D013234:Stem Cells; D014054:Tomography
D006046:Gold; D012822:Silicon Dioxide
MSOT; gold nanorods; photoacoustic imaging; plasmon coupling; silica; stem cells