title: Optimization of Pathogen Capture in Flowing Fluids with Magnetic Nanoparticles.
abstract: Magnetic nanoparticles have been employed to capture pathogens for many biological applications; however, optimal particle sizes have been determined empirically in specific capturing protocols. Here, a theoretical model that simulates capture of bacteria is described and used to calculate bacterial collision frequencies and magnetophoretic properties for a range of particle sizes. The model predicts that particles with a diameter of 460 nm should produce optimal separation of bacteria in buffer flowing at 1 L h(-1) . Validating the predictive power of the model, Staphylococcus aureus is separated from buffer and blood flowing through magnetic capture devices using six different sizes of magnetic particles. Experimental magnetic separation in buffer conditions confirms that particles with a diameter closest to the predicted optimal particle size provide the most effective capture. Modeling the capturing process in plasma and blood by introducing empirical constants (ce ), which integrate the interfering effects of biological components on the binding kinetics of magnetic beads to bacteria, smaller beads with 50 nm diameters are predicted that exhibit maximum magnetic separation of bacteria from blood and experimentally validated this trend. The predictive power of the model suggests its utility for the future design of magnetic separation for diagnostic and therapeutic applications.
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.|Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, 02139, USA.
authors.forename: Joo H
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 08544, USA.
authors.forename: Eujin
authors.initials: E
authors.lastname: Um
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Diaz
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.
authors.forename: Harry
authors.initials: H
authors.lastname: Driscoll
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Rodas
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.
authors.forename: Karel
authors.initials: K
authors.lastname: Domansky
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Watters
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Super
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 08544, USA.
authors.forename: Howard A
authors.initials: HA
authors.lastname: Stone
authors.affiliation: Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA.|Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, 02139, USA.|Vascular Biology Program, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Donald E
authors.initials: DE
authors.lastname: Ingber
mesh_terms: D017848:Blood-Borne Pathogens / Q000302:isolation & purification*; D002138:Calibration; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D005434:Flow Cytometry / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D006801:Humans; D056656:Lab-On-A-Chip Devices; D058185:Magnetite Nanoparticles / Q000592:standards; D008828:Microbiological Techniques / Q000379:methods; D008962:Models, Theoretical; D013211:Staphylococcus aureus / Q000302:isolation & purification; D013242:Sterilization / Q000295:instrumentation / Q000379:methods*
chemical_list: D058185:Magnetite Nanoparticles
keywords: MBL; magnetic nanoparticles; magnetic separation; microfluidics; sepsis