Laboratoire Matière et Systèmes Complexes

Séminaires internes du lundi 3 octobre ; Amanda Andriola-Brun et Cecilia Galindo-Gonzalez

1. Amanda Brun

Photosensitizer-loaded magnetic vesicles as a new MRI-trackable biogenic nano-platform for multimodal targeted cancer theranostics

Iron oxide nanoparticles are responsible to magnetic field allowing them to be manipulated, tracked, imaged and remotely heated. Such key features open up a wide field of applications in medicine which includes cell separation, magnetic force-based tissue engineering, MRI tracking of transplanted cells, magnetic drug targeting and hyperthermia. We present here a new strategy to design a biogenic nano-platform for multimodal therapy. Enclosing magnetic particles within biological vesicles could facilitate circulation in vivo and interaction with cells. Our approach consists of cell-derived magnetic vesicles which were loaded with a photosensitizer drug (m-THPC). In order to produce them, the first experimental step was the uptake of magnetic nanoparticles (8-nm maghemite particles stabilized by citrate ions) and the photosensitizer by macrophages derived from monocyte cell line. As a second step, the release of magnetic photosensitizer-loaded vesicles was triggered by culturing such cells in serum-deprived medium. A micromagnetophoresis experiment of the cell-released vesicles revealed both magnetophoretic mobility and red fluorescence emission due to photosensitizer. In vitro tests demonstrated that such vesicles were able to transfer their cargo into tumor cells. Transfer could be spatially modulated by a magnetic field gradient clearly indicating a magnetic targeting effect. Additionally, MRI detection was demonstrated in both in vitro and in TC1 tumor-bearing mice after intratumoral vesicle injection. In brief, photosensitizer-loaded magnetic vesicles derived from macrophages were successfully produced. Their properties enabled photosensitizer targeting and MRI detection. Besides, photodynamic therapy may be enhanced by magnetically induced hyperthermia.

2 - Cecilia Galindo-Gonzalez

Etude de matériaux nanocomposites magnéto-stimulables à base de biopolymères.

De récents progrès en chimie, physique et biologie combinés à des besoins dans les secteurs biomédical, pharmaceutique, nano et biotechnologies ont conduit à élaborer de nouveaux matériaux nanocomposites aux propriétés modulables en fonction des conditions environnementales. En particulier les matériaux magnéto-stimulables sont particulièrement adaptés pour des modifications rapides de leurs propriétés par application d’un champ magnétique. Nous présentons ainsi l’élaboration et l’étude des propriétés de nouveaux matériaux nanocomposites magnéto-stimulables élaborés par introduction de nanoparticules magnétiques fonctionnalisées dans des réseaux de biopolymères qui présentent l’avantage par rapport aux réseaux de polymères synthétiques d’être biodégradables, non toxiques et biocompatibles avec les molécules biologiques, les cellules et les tissus.