Loading monocytes with magnetic nanoparticles enables their magnetic control without toxicity.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cell Biology

Background:

• Superparamagnetic iron oxide nanoparticles (SPIONs) offer potential for magnetically guiding cells to specific sites.
• This technique can enhance tumor accumulation of monocytes for applications like chimeric antigen receptor (CAR) monocyte immunotherapy.

Purpose of the Study:

• To investigate the loading of monocytic THP-1 cells with SPIONs.
• To analyze the impact of SPIONs on cell viability and reactive oxygen species (ROS) generation.
• To evaluate the magnetic enrichment of SPION-loaded cells and compare it with computational simulations.

Main Methods:

• THP-1 cells were incubated with citrate-coated SPIONs (SPION Citrate ) or citrate-stabilized gold-coated SPIONs (SPION Gold ).
• Particle uptake was confirmed using transmission electron microscopy and atomic emission spectroscopy.
• Biocompatibility and ROS generation were assessed via flow cytometry.
• Magnetic enrichment was evaluated using flow slides and a Neodym magnet, with data compared to a computational model.

Main Results:

• THP-1 cells successfully ingested SPIONs.
• SPIONs demonstrated excellent biocompatibility with minimal ROS generation.
• SPION-loaded cells showed magnetic accumulation at areas of maximal magnetic field and force, consistent with computational predictions.

Conclusions:

• SPIONs can be effectively loaded into THP-1 cells, imparting magnetic steerability without compromising biocompatibility.
• The developed computational model accurately predicts the magnetic accumulation of SPION-loaded cells.
• This approach facilitates a more systematic and efficient design space exploration for future applications.