Rationally designed magnetic nanoparticles as anticoagulants for blood purification.

Heparin-based anticoagulant drugs are widely used for the prevention of blood clotting during extracorporeal circuit (bloodlines or cassette system) and surgical procedures as well as for the treatment of thromboembolic events. However, these anticoagulants are associated with bleeding risks that demand continuous monitoring and neutralization with antidotes. We explore the possibility of utilizing anticoagulants for blood clotting prevention, then removing them before transfusing the blood back to body, thus avoid bleeding risks. Here, we report on the strength of a strategy to solve problems with bleeding risks by rationally designing and using superparamagnetic iron oxide nanoparticles (SPIONs) with layer-by-layer self-assembled heparin. The morphology of these SPIONs was investigated by using dynamic light scattering and transmission electron microscopy. In vitro assays demonstrated superior efficacy and safety profiles and significantly mitigated conventional heparin-induced bleeding risks. In addition, the in vivo assay in a model animal (dog) proved that it is possible to use magnetic anticoagulant (MAC) in blood purification. The new magnetic anticoagulant drugs may benefit patients undergoing high-risk surgical procedures and may overcome anticoagulant-related bleeding problems to a great extent.