Department of Chemistry
ORCID IDs
Qixian Chen: https://orcid.org/0000-0002-3091-671X
M. Francesca Ottaviani: https://orcid.org/0000-0002-4681-4718
Andrzej Rajca: https://orcid.org/0000-0002-8856-1536
Jeremiah A. Johnson: https://orcid.org/0000-0001-9157-6491
Date of this Version
2017
Citation
ACS Cent. Sci. 2017, 3, 800−811
DOI: 10.1021/acscentsci.7b00253
Abstract
Metal-free magnetic resonance imaging (MRI) agents could overcome the established toxicity associated with metal-based agents in some patient populations and enable new modes of functional MRI in vivo. Herein, we report nitroxidefunctionalized brush-arm star polymer organic radical contrast agents (BASP-ORCAs) that overcome the low contrast and poor in vivo stability associated with nitroxide-based MRI contrast agents. As a consequence of their unique nanoarchitectures, BASP-ORCAs possess per-nitroxide transverse relaxivities up to ∼44-fold greater than common nitroxides, exceptional stability in highly reducing environments, and low toxicity. These features combine to provide for accumulation of a sufficient concentration of BASP-ORCA in murine subcutaneous tumors up to 20 h following systemic administration such that MRI contrast on par with metal-based agents is observed. BASP-ORCAs are, to our knowledge, the first nitroxide MRI contrast agents capable of tumor imaging over long time periods using clinical high-field 1H MRI techniques.
Includes Supplementary material
Comments
This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes