Open AccessCylinders vs. Spheres: Biofluid Shear Thinning in Driven Nanoparticle Transport
Author(s) -
Jeremy Cribb,
Timothy D. Meehan,
Sheel Shah,
Kwan Skinner,
R. Superfine
Publication year - 2010
Publication title -
annals of biomedical engineering
Language(s) - English
Resource type - Journals
eISSN - 1573-9686
pISSN - 0090-6964
DOI - 10.1007/s10439-010-0084-5
Subject(s) - viscoelasticity , rheology , magnetic nanoparticles , materials science , shear thinning , nanoparticle , viscosity , particle (ecology) , magnetic field , spheres , complex fluid , shear (geology) , nanotechnology , mechanics , chemical physics , physics , composite material , oceanography , quantum mechanics , astronomy , geology
Increasingly, the research community applies magnetophoresis to micro and nanoscale particles for drug delivery applications and the nanoscale rheological characterization of complex biological materials. Of particular interest is the design and transport of these magnetic particles through entangled polymeric fluids commonly found in biological systems. We report the magnetophoretic transport of spherical and rod-shaped particles through viscoelastic, entangled solutions using lambda-phage DNA (λ-DNA) as a model system. In order to understand and predict the observed phenomena, we fully characterize three fundamental components: the magnetic field and field gradient, the shape and magnetic properties of the probe particles, and the macroscopic rheology of the solution. Particle velocities obtained in Newtonian solutions correspond to macroscale rheology, with forces calculated via Stokes Law. In λ-DNA solutions, nanorod velocities are 100 times larger than predicted by measured zero-shear viscosity. These results are consistent with particles experiencing transport through a shear thinning fluid, indicating magnetically driven transport in shear thinning may be especially effective and favor narrow diameter, high aspect ratio particles. A complete framework for designing single-particle magnetic-based delivery systems results when we combine a quantified magnetic system with qualified particles embedded in a characterized viscoelastic medium.