14^th Pacific Polymer Conference – Kauai, Hawaii, USA.

¹⁹F-MRI offers a unique diagnostic platform with minimal endogenous background signal in vivo and increased sensitivity.  Consequently, a targeted polyfluorinated contrast enhancement agent would be of significant benefit to clinicians for the diagnosis of a variety of diseases.  This report describes the synthesis of a hyperbranched ¹⁹F-MRI contrast enhanced polymer that was targeted towards a variety of carcinomas, and is “switched on” in cancerous tissue via a stimuli-responsive linker. A Gd³⁺ bound DOTA chelator connected via a cleavable disulfide linker was incorporated into the polymer.  While bound, the T2 of ¹⁹F remained too short to detect; but when cleaved by glutathione the ¹⁹F signal was observed, as the Gd³⁺ was no longer in close enough proximity to elicit a relaxation effect.  The T1 and T2s of both ¹H and ¹⁹F were measured for the polymer in varying concentrations of glutathione to illustrate this concept, yielding promising results.