Rapid toxicity screening of novel PASADENA MRI contrast agents
Ross B, Ingram M, Bhattacharya P, Ward B, Techy G, Freundlich A
Huntington Medical Research Institutes, California Institute of Technology
The PASADENA method of in vivo MR-imaging results in >10,000 fold signal increase and sub-second images but employs toxic 13C contrast agents. Compounds used as contrast agents were assessed for cytotoxicity. Dose-response curves were expressed as IC10/50. In vitro toxicity of the hydrogenation-catalyst, Perfos, was entirely eliminated by passage through a membrane filter. A novel, water-soluble PASADENA reagent, sodium cis-fumarate showed cytotoxicity two orders of magnitude lower than 2-hydroxyethyl acrylate (HEA), precursor to the sole existing PASADENA reagent 2-hydroxyethyl propionate (HEP). 13C cis-fumarate provides a safer, metabolizable contrast agent for in vivo hyper-polarized 13C imaging and spectroscopy.