A Polymer-Based Magnetic Resonance Tracer for Visualization of Solid Tumors by C-13 Spectroscopic Imaging

作者：Suzuki Yoshikazu^*; Iida Mitsuru; Miura Iwao; Inubushi Toshiro; Morikawa Shigehiro

来源：PLos One, 2014, 9(7): e102132.

DOI：10.1371/journal.pone.0102132

Morphological imaging precedes lesion-specific visualization in magnetic resonance imaging (MRI) because of the superior ability of this technique to depict tissue morphology with excellent spatial and temporal resolutions. To achieve lesion-specific visualization of tumors by MRI, we investigated the availability of a novel polymer-based tracer. Although the C-13 nucleus is a candidate for a detection nucleus because of its low background signal in the body, the low magnetic resonance sensitivity of the nucleus needs to be resolved before developing a C-13-based tracer. In order to overcome this problem, we enriched polyethylene glycol (PEG), a biocompatible polymer, with C-13 atoms. C-13-PEG40,000 (C-13-PEG with an average molecular weight of 40 kDa) emitted a single C-13 signal with a high signal-to-noise ratio due to its ability to maintain signal sharpness, as was confirmed by in vivo investigation, and displayed a chemical shift sufficiently distinct from that of endogenous fat. C-13-PEG40,000 intravenously injected into mice showed long retention in circulation, leading to its effective accumulation in tumors reflecting the well-known phenomenon that macromolecules accumulate in tumors because of leaky tumor capillaries. These properties of C-13-PEG40,000 allowed visualization of tumors in mice by C-13 spectroscopic imaging. These findings suggest that a technique based on C-13-PEG is a promising strategy for tumor detection.

• 出版日期2014-7-9