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Accueil > La recherche > Priorité T2 : Biomicrosystèmes, Bioélectrochimie et Bioélectromagnétisme > Axe Microsystèmes

Magnetic manipulation of biological cells

par Naoufel HADDOUR - publié le , mis à jour le

The development of methods dedicated to cell positioning on surfaces is an important challenge in cellular biology. We work on the development of new cell patterning methods on micromagnet arrays by using negative and positive magnetophoresis.

Negative magnetophoresis

In the context of a project initiated by the G2Elab in Grenoble, we have studied the manipulation of unlabeled (non-magnetic) cells by negative magnetophoresis onto micromagnet arrays producing regularly spaced magnetic traps where cells can be confined without any contact. As such magnetic trapping required a cell magnetic susceptibility lower than that of the medium, we placed cells in an aqueous solution enriched in paramagnetic ions.
Thus, cells were directed away from magnet surfaces towards ’traps’, i.e. stable positions, corresponding to minimum energy levels. Manipulation of cells by negative magnetophoresis requires the production of high magnetic field gradients, ensuring significant forces. Therefore, micro- magnets are particularly interesting for the targeted application, since the field gradient increases as magnet dimensions are reduced. Such micro-magnets are designed and fabricated by the Institut Neel of Grenoble in partnership with the G2Elab.

A) Diamagnetic trapping of yeast cells onto the micromagnet array- B) Isovalue lines of magnetic potential energy and vector plot of ∇(B2) in a horizontal plane situated right above the micromagnets

Positive magnetophoresis

We also study the contactless manipulation of cells and cell models such as liposomes by positive magnetophoresis onto micro-structured magnet array. This manipulation method involves the magnetic labelling of cells or cell models with magnetic nanoparticles. Indeed, this magnetic labeling increases cell magnetic susceptibility that becomes higher than that of the biological media in which cells are usually handled. Under these conditions, the labeled cells are attracted onto the micromagnet surface towards positions where the magnetic field is strongest.

A) Norme of Magnetic induction in the plane situated right at the surface of the magnetic film – B) Magneto-optic image of the multipole pattern obtained in the flat NdFeB film – C) Fluorescent and magnetic liposomes attracted towards field maxima.

These projects are carried out with :
- µ SYSTEMES team of G2Elab laboratory.
- Micro and NanoMagnetism team of Néel institute.
- Structures Nano- et MicroStructures team of MATEIS laboratory.
- Chemistry and Inorganic Materials team of IPCMS.

- Pivetal J., Osman O., Vezy C., Frénéa-Robin M., Dumas-Bouchiat F., Dempsey NM., Givord D., Simonet P., Buret F., Reyne G., Haddour N. 2010. Trapping of Magnetically-Labelled Liposomes on Flat Micro-Patterned Hard Magnetic Films. AIP Conference Proceedings.1311 : 192-197. Lien

- M. Frénéa-Robin, H. Chetouani, N. Haddour, H. Rostaing, J. Laforet, and G. Reyne, "Contactless diamagnetic trapping of living cells onto a micromagnet array," IEEE Engineering in Medicine and Biology Society, 2008, 3360-3363. Lien