title: Prolonged Dye Release from Mesoporous Silica-Based Imaging Probes Facilitates Long-Term Optical Tracking of Cell Populations In Vivo.
abstract: Nanomedicine is gaining ground worldwide in therapy and diagnostics. Novel nanoscopic imaging probes serve as imaging tools for studying dynamic biological processes in vitro and in vivo. To allow detectability in the physiological environment, the nanostructure-based probes need to be either inherently detectable by biomedical imaging techniques, or serve as carriers for existing imaging agents. In this study, the potential of mesoporous silica nanoparticles carrying commercially available fluorochromes as self-regenerating cell labels for long-term cellular tracking is investigated. The particle surface is organically modified for enhanced cellular uptake, the fluorescence intensity of labeled cells is followed over time both in vitro and in vivo. The particles are not exocytosed and particles which escaped cells due to cell injury or death are degraded and no labeling of nontargeted cell populations are observed. The labeling efficiency is significantly improved as compared to that of quantum dots of similar emission wavelength. Labeled human breast cancer cells are xenotransplanted in nude mice, and the fluorescent cells can be detected in vivo for a period of 1 month. Moreover, ex vivo analysis reveals fluorescently labeled metastatic colonies in lymph node and rib, highlighting the capability of the developed probes for tracking of metastasis.
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Rosenholm
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.|Laboratory of Physical Chemistry, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland.
authors.forename: Tina
authors.initials: T
authors.lastname: Gulin-Sarfraz
authors.affiliation: Department of Clinical Science, University of Bergen, Norway.|Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland.
authors.forename: Veronika
authors.initials: V
authors.lastname: Mamaeva
authors.affiliation: Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland.|Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Niemi
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Ezgi
authors.initials: E
authors.lastname: Özliseli
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Diti
authors.initials: D
authors.lastname: Desai
authors.affiliation: Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland.|Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Antfolk
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.|Laboratory of Physical Chemistry, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland.
authors.forename: Eva
authors.initials: E
authors.lastname: von Haartman
authors.affiliation: Laboratory of Physical Chemistry, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland.
authors.forename: Desiré
authors.initials: D
authors.lastname: Lindberg
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.|Laboratory of Biophysics, Faculty of Medicine, University of Turku, FI-20520, Turku, Finland.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Prabhakar
authors.affiliation: Laboratory of Biophysics, Faculty of Medicine, University of Turku, FI-20520, Turku, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Näreoja
authors.affiliation: Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland.|Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.|Department of Biomedical Engineering, Institute for Complex Molecular Systems, Technical University of Eindhoven, 2612, Eindhoven, The Netherlands.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Sahlgren
mesh_terms: D000818:Animals; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D058948:Cell Tracking / Q000379:methods*; D003952:Diagnostic Imaging; D005089:Exocytosis; D005260:Female; D005434:Flow Cytometry; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D008819:Mice, Nude; D053758:Nanoparticles / Q000648:ultrastructure; D055620:Optical Phenomena; D016062:Porosity; D045663:Quantum Dots / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D023041:Xenograft Model Antitumor Assays
chemical_list: D005456:Fluorescent Dyes; D012822:Silicon Dioxide
keywords: cellular tracking; fluorescent probes; imaging; mesoporous materials; silica