Detection of intramyocardially injected DiR-labeled mesenchymal stem cells by optical and optoacoustic tomography

• Main Authors: Markus T. Berninger, Pouyan Mohajerani, Moritz Wildgruber, Nicolas Beziere, Melanie A. Kimm, Xiaopeng Ma, Bernhard Haller, Megan J. Fleming, Stephan Vogt, Martina Anton, Andreas B. Imhoff, Vasilis Ntziachristos, Reinhard Meier, Tobias D. Henning
• Format: Article
• Language: English
• Published: Elsevier 2017-06-01
• Series: Photoacoustics
• Subjects: Fluorescence molecular imaging; Multispectral optoacoustic tomography; Rabbit heart; Mesenchymal stem cells; Cell labeling; Intramyocardial injection
• Online Access: http://www.sciencedirect.com/science/article/pii/S2213597916300313

The distribution of intramyocardially injected rabbit MSCs, labeled with the near-infrared dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbo-cyanine-iodide (DiR) using hybrid Fluorescence Molecular Tomography-X-ray Computed Tomography (FMT-XCT) and Multispectral Optoacoustic Tomography (MSOT) imaging technologies, was investigated. Viability and induction of apoptosis of DiR labeled MSCs were assessed by XTT- and Caspase-3/-7-testing in vitro. 2 × 106, 2 × 105 and 2 × 104 MSCs labeled with 5 and 10 μg DiR/ml were injected into fresh frozen rabbit hearts. FMT-XCT, MSOT and fluorescence cryosection imaging were performed. Concentrations up to 10 μg DiR/ml did not cause apoptosis in vitro (p > 0.05). FMT and MSOT imaging of labeled MSCs led to a strong signal. The imaging modalities highlighted a difference in cell distribution and concentration correlated to the number of injected cells. Ex-vivo cryosectioning confirmed the molecular fluorescence signal. FMT and MSOT are sensitive imaging techniques offering high-anatomic resolution in terms of detection and distribution of intramyocardially injected stem cells in a rabbit model.