title: Activated MR contrast agents.
abstract: The relative non-specificity of the first generation MR contrast agents has meant that a new approach to their design is required. This review focuses on a new class of more specific or functional agents. These are the so-called "activated", "smart" or "responsive" contrast agents. The relaxivity of an activated contrast agent is responsive to (or can be modulated by) a particular in vivo stimulus such as a change in biological environment or activity. More specifically, a "switching on" of contrast in response to an event such as a change in physiological pH, metal ion concentration, enzyme activity or partial pressure of oxygen is sought. The current generation of activated MR contrast agents is discussed herein.
authors.affiliation: Department of Chemistry, University of Leicester, UK. mplowe@le.ac.uk
authors.forename: Mark P
authors.initials: MP
authors.lastname: Lowe
mesh_terms: D000818:Animals; D001704:Biopolymers / Q000032:analysis / Q000378:metabolism*; D003287:Contrast Media; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D008967:Molecular Biology / Q000379:methods; D015336:Molecular Probe Techniques; D015335:Molecular Probes; D043942:Nanotubes / Q000737:chemistry / Q000648:ultrastructure; D014018:Tissue Distribution
chemical_list: D001704:Biopolymers; D003287:Contrast Media; D015335:Molecular Probes