Electrosprayed Synthesis of Red‐Blood‐Cell‐Like Particles with Dual Modality for Magnetic Resonance and Fluorescence Imaging

Abstract Red blood cells (RBCs) are able to avoid filtration in the spleen to prolong their half‐time in the body because of their flexibility and unique shape, or a concave disk with diameter of some 10 μm. In addition, they can flow through capillary blood vessels, which are smaller than the diameter of RBCs, by morphing into a parachute‐like shape. In this study, flexible RBC‐like polymer particles are synthesized by electrospraying based on electrospinning. Furthermore, magnetite nanoparticles and fluorescent dye are encapsulated in the particles via in situ hydrolysis of an iron–organic compound in the presence of celluloses. The superparamagnetic behavior of the particles is confirmed by low‐temperature magnetic measurements. The particles exhibited not only a dark contrast in magnetic resonance imaging (MRI), but also effective fluorescence. The RBC‐like particles with flexibility are demonstrated to have a dual‐modality for MRI and fluorescence imaging.