Séminaire (Valrose): Hélène Joisten

Vendredi, 10 Novembre, 2017

11h- Site Valrose

Magnetic microparticles vibration at low frequency: a new approach in fighting cancer

In the field of biotechnology, magnetic nanoparticles are increasingly used for a variety of applications since they allow to exert forces and torques on biological species. Based on top-down approaches (deposition, etching, lift-off), several types of micro/nano particles were prepared for various purposes. They include synthetic antiferromagnetic particles, vortex microdisks [1], magnetite multidomain particles, magnetic nanoswimmers.  A first part of the work has aimed at controlling the agglomeration/dispersion of these particles [2]. To avoid the agglomeration of the particles in solution, these particles are designed to exhibit superparamagnetic-like response and must have a susceptibility below a certain critical threshold to avoid their mutual self-polarization. Thanks to their anisotropic properties, they offer new degrees of freedom in their manipulation when dispersed in solutions [3]. This allows designing ferrofluids with novel properties. In particular interesting optical properties can be obtained [4]. Concerning biomedical applications, a recent approach for cancer cells destruction was proposed, based on the triggering of cancer cell spontaneous death through the mechanical vibration of anisotropic magnetic nanoparticles attached to the cells membrane at low frequencies (20Hz). The induction of cancer cells death was demonstrated in earlier work on glioblastoma cancer cells [5] and in this study with NiFe vortex particles on renal human cancer cells [6]. These results open great perspectives for new cancer treatments with reduced side effects.

[1] Leulmi, S., et al, Appl.Phys.Lett. 13, (2013) 132412.
[2] Joisten, H., et alAppl.Phys.Lett. 97, (2010) 253112. 
[3] Courcier, T.,et al, Appl.Phys.Lett. 99 (2011) 093107.
[4] A. Truong, et al, Sc. Reports 6,  31634 (2016). 
[5] D.H. Kim, et al, Nat. Mater. 9, (2010) 165–71. 
[6]  Leulmi, S., et al., Nanoscale, 7, (2015) 15904.