Magnetic living cells: New tools for cell imaging, tissue engineering and cell therapies
Claire Wilhelm (Université Paris 7)
Recent advances in cell therapy and tissue engineering opened new windows for regenerative medicine, but still necessitate innovative techniques to create and image functional tissues. One promising approach is to associate magnetic nanoparticles with cells in order to supply them with sufficient magnetization to be detectable by MRI or manipulated by magnetic forces, while maintaining cell viability and functionalities. A few years ago, we proposed the use of anionic iron oxide nanoparticles as efficient agents for cell internalisation without impacting cell functions. Recently we examined the influence of the amount of internalized iron and the state of nanoparticle aggregation on the capacity for mesenchymal stem cell differentiation and MRI single cell tracking. We then demonstrated that high resolution Magnetic Resonance Imaging (MRI) allowed combining cellular-scale resolution with the ability to detect two cell types simultaneously at any tissue depth. In parallel, we addressed the challenge to create a functional tissue from stem cells in vitro. The aim was to confine stem cells in three dimensions at the millimetric scale by using home-designed miniaturized magnetic devices, in order to create cellular patterns for stem cell differentiation and tissue engineering.
Finally magnetic nanoparticles show also great promises for antitumor cell therapies, in particular using the magnetic hyperthermia modality. Cellular internalization of magnetic nanoparticles localizes the source of heat in the internal volume of the cell, with direct application for tumor cell therapies. The combination of cell-derived vesicles with magnetic nanoparticles creates multifunctional bio-inspired nanovectors with promising potential for diagnosis and therapy.