Fig. 2: Schematic illustration of the “partially complexed” method for activating conjugated polymer nanoparticles in T2 MRI.
From: Non-metallic T2-MRI agents based on conjugated polymers
For T2 MRI inactive PPy nanoparticles, paramagnetic polarons are block from water protons by strong “spin–spin” interactions between polarons. For PPy nanoparticles with weak T2 MRI contrast, above interactions are moderately reduced by catechol derivatives used in “partially complexed” method. For T2 MRI active PPy nanoparticles, bipolarons further increase the interactions between paramagnetic polarons and water protons.
