Analysis of driven nanorod transport through a biopolymer matrix

• We study the magnetophoretic transport of 18 nm diameter nickel nanorods through a protein-rich matrix.
• We note that nanorods move with low velocity (less than 1 μm per minute) for approximately 95% of the total experiment time.
• We plot nanorod velocity over the course of hundreds of seconds.
• Finally, we observe intra-particle magnetophoresis events in this viscoelastic environment.

Applying magnetic fields to guide and retain drug-loaded magnetic particles in vivo has been proposed as a way of treating illnesses. Largely, these efforts have been targeted at tumors. One significant barrier to long range transport within tumors is the extracellular matrix (ECM). We perform single particle measurements of 18 nm diameter nanorods undergoing magnetophoresis through ECM, and analyze the motion of these nanorods in two dimensions. We observe intra-particle magnetophoresis in this viscoelastic environment and measure the fraction of time these nanorods spend effectively hindered, versus effectively translating.