JSM-Seminar: Magnetic field-induced supracolloidal assemblies for biophysical applications
Jean-Francois Berret, Univ. Paris, France
- 15.Dec.2011 11:00
The emergence of novel materials and processing at the nanoscale has set the conditions for the fabrication of a wide range of nano-objects and multilevel nanostructured networks. In this communication we report a simple and versatile waterborne synthesis of magnetic nanowires following the innovative concept of electrostatic ‘’desalting transition’’. Highly persistent superparamagnetic nanowires are generated from the controlled assembly of oppositely charged nanoparticles and polymers . The particles considered for the assembly are 10 nm iron oxide particles. The wires have diameters of 200 nm and lengths comprised between 1 mm and 1/2 mm. The wires are rigid and able to reorient via the application of a magnetic field. In the second part of the talk, we review recent results on the interactions, toxicity and uptake of these nanomaterials with mammalian cells. Results were obtained for the single 10 nm particles with different coating and for the micrometer long nanowires . Our studies reveal that the physico-chemical characteristics of the particles/aggregates play an important role in the interactions with living cells. The nanowires are finally tested as probes for passive and active microrheology experiments. The mechanical responses of the intracellular medium of cells is presented and compared to that of model viscoelastic liquids.
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