The application of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) in drug delivery, magnetic resonance imaging, cell tracking, and hyperthermia has been long exploited regarding to their inducible magnetic properties. Nevertheless, SPIONs remain rapidly cleared from the circulation by the reticuloendothelial system (RES) or mononuclear phagocyte system, with uptake dependent on several factors such as the hydrodynamic diameter, electrical charge and surface coating. This rapid clearance of SPION-based theranostic agents from circulation is one of the main challenges hampering the medical applications that differ from the RES targeting. This work proposes a strategy to render biocompatible SPIONs through their encapsulation in the Red Blood Cells (RBCs). In this work, the research has been focused on the multi-step optimization of chemical synthesis of magnetic nanoparticles (MNPs), precisely …