2D modeling and preliminary in vitro investigation of a prototype high gradient magnetic separator for biomedical applications.

High gradient magnetic separation (HGMS) of magnetic materials from fluids or waste products has many established industrial applications. However, there is currently no technology employing HGMS for ex-vivo biomedical applications, such as for the removal of magnetic drug- or toxin-loaded spheres from the human blood stream. Importantly, human HGMS applications require special design modifications as, in contrast to conventional use where magnetic elements are permanently imbedded within the separation chambers, medical separators need to avoid direct contact between the magnetic materials and blood to reduce the risk of blood clotting and to facilitate convenient and safe treatment access for many individuals. We describe and investigate the performance of a magnetic separator prototype designed for biomedical applications. First, the capture efficiency of a prototype HGMS separator unit consisting of a short tubing segment and two opposing magnetizable fine wires along the outside of the tubing was investigated using 2D mathematical modeling. Second, the first-pass effectiveness to remove commercially available, magnetic polystyrene spheres from human blood using a single separator unit was experimentally verified. The theoretical and experimental data correlated well at low flow velocities (<5.0 cm/s) and high external magnetic fields (>0.05 T). This prototype separator unit removed >90% in a single pass of the magnetic spheres from water at mean flow velocity < or =8.0 cm/s and from blood mimic fluids (ethylene glycol-water solutions) at mean flow velocity < or =2.0 cm/s. In summary, we describe and prove the feasibility of a HGMS separator for biomedical applications.

[1]  M C Yang,et al.  In vitro characterization of the occurrence of hemolysis during extracorporeal blood circulation using a mini hemodialyzer. , 2000, ASAIO journal.

[2]  T. Alan Hatton,et al.  High-Gradient Magnetic Separation of Magnetic Nanoclusters , 2005 .

[3]  Andreas Radbruch,et al.  High gradient magnetic cell separation with MACS. , 1990, Cytometry.

[4]  Michael D Kaminski,et al.  A novel human detoxification system based on nanoscale bioengineering and magnetic separation techniques. , 2007, Medical hypotheses.

[5]  Armin D. Ebner,et al.  Application of high gradient magnetic separation principles to magnetic drug targeting , 2004 .

[6]  M. Portaccio,et al.  The α1-antitrypsin/elastase Complex as an Experimental Model for Hemodialysis in Acute Catabolic Renal Failure, Extracorporeal Blood Circulation and Cardiocirculatory Bypass , 2002 .

[7]  Michael D. Kaminski,et al.  Detoxification of blood using injectable magnetic nanospheres: A conceptual technology description , 2005 .

[8]  Michael D. Kaminski,et al.  Magnetically guided plasminogen activator-loaded designer spheres for acutestroke lysis. , 2007 .

[9]  Kristin Comella,et al.  Separation of a Breast Cancer Cell Line from Human Blood Using a Quadrupole Magnetic Flow Sorter , 2001, Biotechnology progress.

[10]  A. Bruno Frazier,et al.  Continuous magnetophoretic separation of blood cells in microdevice format , 2004 .

[11]  Andreas Manz,et al.  On-chip free-flow magnetophoresis: continuous flow separation of magnetic particles and agglomerates. , 2004, Analytical chemistry.

[12]  J. Chalmers,et al.  Flow Through, Immunomagnetic Cell Separation , 1998, Biotechnology progress.

[13]  J. Chalmers,et al.  Analytical magnetapheresis of ferritin-labeled lymphocytes. , 1995, Analytical chemistry.

[14]  R D Swartz,et al.  Preservation of plasma volume during hemodialysis depends on dialysate osmolality. , 1982, American journal of nephrology.

[15]  Nuray Karapinar,et al.  Magnetic separation of ferrihydrite from wastewater by magnetic seeding and high-gradient magnetic separation , 2003 .

[16]  Challa S. S. R. Kumar,et al.  Nanofabrication towards biomedical applications : techniques, tools, applications, and impact , 2005 .

[17]  J.H.P. Watson,et al.  Magnetic separator with transversally magnetised disk permanent magnets , 2002 .

[18]  Marc D. Porter,et al.  Magnetic particle diverter in an integrated microfluidic format , 2005 .

[19]  Paulo A. Augusto,et al.  Magnetic shielding: application to a new magnetic separator and classifier , 2004 .

[20]  Jan Greve,et al.  Magnetic field design for selecting and aligning immunomagnetic labeled cells. , 2002, Cytometry.

[21]  Robert H. Austin,et al.  Continuous microfluidic immunomagnetic cell separation , 2004 .

[22]  Maciej Zborowski,et al.  Magnetophoretic Cell Sorting Is a Function of Antibody Binding Capacity , 2003, Biotechnology progress.

[23]  Armin D. Ebner,et al.  Analysis of magnetic drug carrier particle capture by a magnetizable intravascular stent—2: Parametric study with multi-wire two-dimensional model , 2005 .

[24]  Costas Tsouris,et al.  High-gradient magnetically seeded filtration , 2000 .

[25]  Jin-Woo Choi,et al.  A new magnetic bead-based, filterless bio-separator with planar electromagnet surfaces for integrated bio-detection systems , 2000 .

[26]  E. P. Furlani,et al.  Analysis of particle transport in a magnetophoretic microsystem , 2006 .

[27]  William H. Green,et al.  High‐gradient magnetic separation of coated magnetic nanoparticles , 2004 .

[28]  J. Svoboda,et al.  Particle capture in the matrix of a magnetic separator , 1989 .

[29]  D. J. Harrison,et al.  Immunomagnetic T cell capture from blood for PCR analysis using microfluidic systems. , 2004, Lab on a chip.

[30]  R. Goleman.  Macroscopic model of particles’ capture by the elliptic cross-section collector in magnetic separator , 2004 .

[31]  M. Takayasu,et al.  Continuous magnetic separation of blood components from whole blood , 2000, IEEE Transactions on Applied Superconductivity.

[32]  Saibal Roy,et al.  Vibration based electromagnetic micropower generator on silicon , 2006 .