title: Cell creeping and controlled migration by magnetic carbon nanotubes.
abstract: Carbon nanotubes (CNTs) are tubular nanostructures that exhibit magnetic properties due to the metal catalyst impurities entrapped at their extremities during fabrication. When mammalian cells are cultured in a CNT-containing medium, the nanotubes interact with the cells, as a result of which, on exposure to a magnetic field, they are able to move cells towards the magnetic source. In the present paper, we report on a model that describes the dynamics of this mammalian cell movement in a magnetic field consequent on CNT attachment. The model is based on Bell's theory of unbinding dynamics of receptor-ligand bonds modified and validated by experimental data of the movement dynamics of mammalian cells cultured with nanotubes and exposed to a magnetic field, generated by a permanent magnet, in the vicinity of the cell culture wells. We demonstrate that when the applied magnetic force is below a critical value (about Fc ≈ 10-11 N), the cell 'creeps' very slowly on the culture dish at a very low velocity (10-20 nm/s) but becomes detached from the substrate when this critical magnetic force is exceeded and then move towards the magnetic source.
authors.affiliation: Medical Science Lab, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy. s.raffa@crim.sssup.it.
authors.forename: V
authors.initials: V
authors.lastname: Raffa
authors.forename: O
authors.initials: O
authors.lastname: Vittorio
authors.forename: G
authors.initials: G
authors.lastname: Ciofani
authors.forename: V
authors.initials: V
authors.lastname: Pensabene
authors.forename: A
authors.initials: A
authors.lastname: Cuschieri