PET reporter genes for noninvasive imaging of gene therapy, cell tracking and transgenic analysis.
ABSTRACT Positron-emission tomography (PET) has been used extensively in the clinic for cancer diagnosis, for staging and for monitoring of therapeutic efficacy. PET has not, however, been used extensively in contemporary animal cancer models. Until recently, appropriate instrumentation was not available and the expertise and knowledge necessary to perform PET analyses in murine models has not been widespread. The fabrication of microPET instruments with appropriate resolution for murine experiments has lead to the establishment of non-invasive techniques for functional imaging. The development of "PET reporter genes" whose activity can be monitored in living animals, based on the reporter gene-dependent sequestration of positron-emitting "PET reporter probes," has lead to innovative analyses of gene expression in transgenic animals, to methods to monitor the location, magnitude and duration of expression for gene therapy vectors and to the ability to non-invasively track the targeting, viability and expansion of cellular therapeutics.
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ABSTRACT: This review covers published literature describing the synthesis of labeled carbohydrates for use in molecular imaging, with a particular focus on the use of nuclear techniques (PET, SPECT). Recent advances in the radiosynthesis of [18F]FDG (electrophilic vs. nucleophilic radiofluorinations), a PET radiotracer based on glucose and the most widely PET tracer currently in use for cancer and inflammatory disease diagnosis, is considered. The powerful impact of [18F]FDG in the clinic has prompted intensive research efforts into glucose-based radiotracers for PET and SPECT imaging. These achievements are also reviewed, along with the use of glycopeptides for nuclear molecular imaging. Finally, recent work on the radionuclide labeling of nucleosides and glycoconjugates is discussed.European Journal of Organic Chemistry 03/2013; 2013(8). DOI:10.1002/ejoc.201201457 · 3.15 Impact Factor
12/2005, Degree: MSc, Supervisor: Pedro Almeida
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ABSTRACT: The successful development of highly sensitive, water-compatible, nontoxic nanoprobes has allowed nanomaterials to be widely employed in various applications. The applicability of highly bright quantum dot (QD)-based probes consisting of QDs on 120 nm silica nanoparticles (NPs) with silica shells is investigated. Their substantial merits, such as their brightness and biocompatibility, for effective bioimaging are demonstrated. Silica-coated, QD-embedded silica NPs (Si@QDs@Si NPs) containing QDs composed of CdSe@ZnS (core-shell) are prepared to compare their structure-based advantages over single QDs that have a similar quantum yield (QY). These Si@QDs@Si NPs exhibit approximately 200-times stronger photoluminescence (PL) than single QDs. Cytotoxicity studies reveal that the Si@QDs@Si NPs are less toxic than equivalent numbers of silica-free single quantum dots. The excellence of the Si@QDs@Si NPs with regard to in vivo applications is illustrated by significantly enhanced fluorescence signals from Si@QDs@Si-NP-tagged cells implanted in mice. Notably, a more advanced version of QD-based silica NPs (Si@mQDs@Si NPs), containing multishell quantum dots (mQDs) composed of CdSe@CdS@ZnS, are prepared without significant loss of QY during surface modification. In addition, the Si@mQDs@Si NPs display a fivefold higher fluorescence activity than the Si@QDs@Si NPs. As few as 400 units of Si@mQDs@Si- NP-internalized cells can be detected in the cell-implanted mouse model.Advanced Functional Materials 05/2012; 22(9). DOI:10.1002/adfm.201102930 · 10.44 Impact Factor