title: Paramagnetic Structures within a Microfluidic Channel for Enhanced Immunomagnetic Isolation and Surface Patterning of Cells.
abstract: In this report, we demonstrate a unique method for embedding magnetic structures inside a microfluidic channel for cell isolation. We used a molding process to fabricate these structures out of a ferrofluid of cobalt ferrite nanoparticles. We show that the embedded magnetic structures significantly increased the magnetic field in the channel, resulting in up to 4-fold enhancement in immunomagnetic capture as compared with a channel without these embedded magnetic structures. We also studied the spatial distribution of trapped cells both experimentally and computationally. We determined that the surface pattern of these trapped cells was determined by both location of the magnet and layout of the in-channel magnetic structures. Our magnetic structure embedded microfluidic device achieved over 90% capture efficiency at a flow velocity of 4 mm/s, a speed that was roughly two orders of magnitude faster than previous microfluidic systems used for a similar purpose. We envision that our technology will provide a powerful tool for detection and enrichment of rare cells from biological samples.
authors.affiliation: Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Sun
authors.affiliation: Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Hamid
authors.initials: H
authors.lastname: Hassanisaber
authors.affiliation: Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Yu
authors.affiliation: Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Sai
authors.initials: S
authors.lastname: Ma
authors.affiliation: Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Scott S
authors.initials: SS
authors.lastname: Verbridge
authors.affiliation: Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Chang
authors.initials: C
authors.lastname: Lu
mesh_terms: D000818:Animals; D002452:Cell Count; D002469:Cell Separation / Q000295:instrumentation*; D004867:Equipment Design; D018189:Immunomagnetic Separation / Q000295:instrumentation*; D056656:Lab-On-A-Chip Devices; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008962:Models, Theoretical; D000067996:RAW 264.7 Cells; D013499:Surface Properties