Magnetic microparticle concentration and collection using a mechatronic magnetic ratcheting system
Oladunni B Adeyiga1, Coleman Murray2,3, Hector E Muñoz4
1Division of Infectious Diseases, David Geffen School of Medicine, Department of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America.
Plos One
|February 18, 2021
Summary
Magnetic ratcheting cytometry rapidly concentrates superparamagnetic iron oxide particles using a novel chip design. This technique shows potential for isolating magnetically labeled cells for diagnostic applications.
Area of Science:
- Biotechnology
- Microfluidics
- Materials Science
Background:
- Magnetic ratcheting cytometry separates magnetic materials based on quantity.
- Previous work demonstrated cell separation using this technique.
Purpose of the Study:
- To demonstrate rapid concentration and collection of superparamagnetic iron oxide particles using a new chip design.
- To explore operating conditions and particle size effects on concentration efficiency.
Main Methods:
- Utilized a mechatronic wheel to generate a cycling magnetic field on a "ratcheting chip" with permalloy micropillars.
- Varied magnetic field frequency and direction to control particle movement.
- Tested concentration of 2.8 μm, 500 nm, and 100 nm superparamagnetic iron oxide particles.
Main Results:
- Achieved a 100-fold surface area concentration of 2.8 μm particles.
- Demonstrated a concentration factor greater than 200% for superparamagnetic iron oxide particles.
- Showed rapid movement and collection of particles across various sizes.
Conclusions:
- Magnetic ratcheting cytometry effectively concentrates superparamagnetic iron oxide particles.
- The system's concentration factor can be improved by optimizing liquid extraction.
- This method holds promise for isolating and concentrating magnetically labeled cells for diagnostic automation.
