Single chain ferritin chimera as an improved MRI gene reporter

Imaging gene expression non-invasively and deep into opaque tissues has been a long-standing goal of molecular science. Optical gene reporters such as green fluorescent protein and luciferase have revolutionized cellular and molecular biology, however their in vivo application is limited, due to poor tissue penetration of visible light. The iron storage protein ferritin forms a paramagnetic ferrihydrite core that affects the relaxation rate of surrounding nuclear spins. Ferritin has recently emerged as an MRI gene reporter for molecular applications, however its detection with MRI still has relatively low sensitivity. In this work we present an improved ferritin chimera, genetically engineered to exhibit stronger paramagnetic properties.