title: Device for continuous extracorporeal blood purification using target-specific metal nanomagnets.
abstract: BACKGROUND
  The present work illustrates how magnetic separation-based blood purification using ultra-strong iron nanomagnets can be implemented into an extracorporeal blood purification circuit. By this promising technique, today's blood purification may be extended to specifically filter high-molecular compounds without being limited by filter cut-offs or column surface saturation.
  
  
  METHODS
  Blood spiked with digoxin (small molecule drug) and interleukin-1β (inflammatory protein) was circulated ex vivo through a device composed of approved blood transfusion lines. Target-specific nanomagnets were continuously injected and subsequently recovered with the aid of a magnetic separator before recirculating the blood.
  
  
  RESULTS
  Magnetic blood purification was successfully carried out under flow conditions: already in single-pass experiments, removal efficiencies reached values of 75 and 40% for digoxin and interleukin-1β, respectively. Circulating 0.5 L of digoxin-intoxicated blood in a closed loop, digoxin concentration was decreased from initially toxic to therapeutic concentrations within 30 min and purification extents of 90% were achieved after 1.5 h.
  
  
  CONCLUSIONS
  Magnetic separation can be successfully implemented into an extracorporeal blood purification device. Simultaneous and specific filtering of high-molecular compounds may offer promising new therapeutic tools for the future treatment of complex diseases, such as sepsis and autoimmune disorders.
authors.affiliation: Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland.
authors.forename: Inge K
authors.initials: IK
authors.lastname: Herrmann
authors.forename: Riccardo E
authors.initials: RE
authors.lastname: Bernabei
authors.forename: Martin
authors.initials: M
authors.lastname: Urner
authors.forename: Robert N
authors.initials: RN
authors.lastname: Grass
authors.forename: Beatrice
authors.initials: B
authors.lastname: Beck-Schimmer
authors.forename: Wendelin J
authors.initials: WJ
authors.lastname: Stark
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D004077:Digoxin / Q000097:blood / Q000276:immunology / Q000302:isolation & purification; D004867:Equipment Design; D006440:Hemofiltration / Q000295:instrumentation*; D006801:Humans; D018189:Immunomagnetic Separation; D053583:Interleukin-1beta / Q000097:blood / Q000276:immunology / Q000302:isolation & purification; D008280:Magnetics / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008863:Microspheres; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010956:Plasmapheresis
chemical_list: D000911:Antibodies, Monoclonal; D053583:Interleukin-1beta; D004077:Digoxin