title: Phthalocyanine photosensitizers as contrast agents for in vivo photoacoustic tumor imaging.
abstract: There is a need for contrast agents for non-invasive diagnostic imaging of tumors. Herein, Multispectral Optoacoustic Tomography (MSOT) was employed to evaluate phthalocyanines commonly used in photodynamic therapy as photoacoustic contrast agents. We studied the photoacoustic activity of three water-soluble phthalocyanine photosensitizers: phthalocyanine tetrasulfonic acid (PcS4), Zn(II) phthalocyanine tetrasulfonic acid (ZnPcS4) and Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4) in phantom and in tumor-bearing mice to investigate the biodistribution and fate of the phthalocyanines in the biological tissues. PcS4 was observed to grant good contrast between the different reticuloendothelial organs and accumulate in the tumor within an hour of post-administration. ZnPcS4 and AlPcS4 offered little contrast in photoacoustic signals between the organs. PcS4 is a promising photoacoustic contrast agent and can be exploited as a photodiagnostic agent.
authors.affiliation: Bio-Optical Imaging Group, Singapore Bioimaging Consortium, Helios #01-02, 11 Biopolis Way, Singapore.
authors.forename: Amalina Bte Ebrahim
authors.initials: AB
authors.lastname: Attia
authors.affiliation: Bio-Optical Imaging Group, Singapore Bioimaging Consortium, Helios #01-02, 11 Biopolis Way, Singapore.
authors.forename: Ghayathri
authors.initials: G
authors.lastname: Balasundaram
authors.affiliation: Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, Technical University Munich, Munich, Germany ; iThera Medical, GmbH, Germany.
authors.forename: Wouter
authors.initials: W
authors.lastname: Driessen
authors.affiliation: Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, Technical University Munich, Munich, Germany ; Technical University of Munich, Germany.
authors.forename: Vasilis
authors.initials: V
authors.lastname: Ntziachristos
authors.affiliation: Bio-Optical Imaging Group, Singapore Bioimaging Consortium, Helios #01-02, 11 Biopolis Way, Singapore ; School of Physics, National University of Ireland, Galway, Ireland.
authors.forename: Malini
authors.initials: M
authors.lastname: Olivo
keywords: (110.4234) Multispectral and hyperspectral imaging; (110.5125) Photoacoustics; (160.1050) Acousto-optical materials; (170.3880) Medical and biological imaging; (170.5120) Photoacoustic imaging; (170.6930) Tissue