Model of Magnetic Particle Capture Under Physiological Flow Rates for Cytokine Removal During Cardiopulmonary Bypass

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Biomagnetic Separation

Background:

• Cytokines contribute to the systemic inflammatory response (SIR) during cardiopulmonary bypass (CPB).
• Targeting these cytokines is crucial for mitigating SIR and improving patient outcomes.
• Existing methods for cytokine removal are limited, especially under high flow conditions.

Purpose of the Study:

• To design and model a physical magnetic filtration system for separating magnetic nanoparticle (MNP)-tagged cytokines.
• To evaluate system performance at physiologically relevant flow rates used in CPB.
• To optimize parameters for efficient MNP capture.

Main Methods:

• Utilized finite element analysis (COMSOL Multiphysics) to solve Navier-Stokes equations for fluid flow and magnetic field.
• Investigated 2D and 3D models of the flow chamber with varying dimensions and magnet array configurations.
• Assessed the impact of flow rate, chamber height, magnet array design, and particle properties on MNP capture efficiency.

Main Results:

• Identified optimal flow chamber dimensions for CPB conditions.
• Demonstrated that magnetic force decreases with increasing chamber height.
• A magnetic "block" array configuration yielded the highest magnetic force.
• MNP-loaded microparticles showed enhanced capture with increased hydrodynamic diameter.

Conclusions:

• The developed model predicts up to 100% capture efficiency in a single pass at 1.75 L/min.
• This work represents a significant advancement in designing magnetic separation systems for CPB.
• The findings will guide future research in optimizing magnetic filtration devices for therapeutic applications.