Nano-DDSs have provided many improvements, such as sensitivity, multimodality, ability to respond to the environment or an external trigger, and theranostics (therapeutics and diagnostics), for preclinical magnetic resonance imaging (MRI). Nanocarriers like polymers, nano-micelle, carbon nano-materials (fullerene and carbon nanotube), and PEGylated liposome, have been investigated and the merits and limitations of each have slowly become clear. This review discusses the progress and unresolved issues for existing nano-DDSs for MRI applications, and summarizes recent work with responsive and theranostic nanocarriers.
- Activatable contrast agents
- Responsive contrast agents