Aggregation of an Endogenous MR Reporter Protein to Increase Relaxivity
Shapiro E, Bennett K, Koretsky A
New York University School of Medicine, National Institutes of Neurological Disease and Stroke
Ferritin has been proposed as a reporter protein for MRI. However, levels of ferritin expression levels in the brain must be relatively high to achieve practical relaxivity changes. In this work, ferritin aggregation was used to improve transverse relaxivity in vitro using cross-linking of ferritin with a succimidyl ester. The cross-linking was then undone by cleaving the spacer between ferritin cages. Because cross-linking can be achieved in-vivo, it is proposed as an endogenous molecular reporter strategy that sensitizes the MR signal to R2 changes on the order of seconds or less.