Hybrid ferritin nanoparticles as activatable probes for tumor imaging

Abstract

Near-infrared fluorescence (NIRF) imaging is emerging as an important tool in preclinical studies.[1–5] As the technology is being established and implemented worldwide, a wave of effort has been spurred to develop novel imaging probes that can accurately recognize and report diseases, such as cancer.[3, 6] One common drawback of NIRF imaging, however, is its high background and as a consequence of that, low specificity.[7, 8] To address this issue, we and others have developed activatable probes with various approaches. Such probes, constructed by bringing into proximity an energy donor and receptor, are designed to be fluorescently quenched at a quiescent stage but activatable when encountering a specific trigger, which leads to a structural or conformational change and restores fluorescence activities.[ 7–9] This technique allows the signals to be only amplified at diseased areas upon a designated environment change, a feature which can greatly improve the signal-to-background ratio.