SPIO nanoparticles and magnetic erythrocytes as contrast agents for biomedical and diagnostic applications

Superparamagnetic iron oxide nanoparticles (SPION) are available since many years and some of them are already approved for human use. New applications are currently emerging and the field is moving from the use of SPION as simply contrast agents, to more complex structures optimized in terms of core, size, shape and coating for different imaging modalities (e.g. MRI vs MPI), and different theranostic applications. Prof. Krishnan M. Kannan has greatly contributed to our understanding of the role of each of these parameters in shaping SPIO best function. Some of these developments are discussed in this short review just as examples. More recently, new cell-based SPIO constructs have also been optimized, moving the field from engineering the nanoparticles to the generation of hybrids cell-nanoparticle constructs. These developments have requested additional SPIO optimizations to maintain nanoparticles biocompatibility and properties and, at the same time, prevent cell damage and maintain cell functionality. Related examples from our lab are also discussed.