In experimental models of glioblastoma and Multiple sclerosis, we took advantage of molecular alterations of the neurovascular cells to address specific targeting via immune cells (monocytes, microglia) and ligands (antibodies and newly screened peptide ligands). The microglia cells were manipulated ex vivo for the heat sensitive expression of a therapeutic gene and incorporated a heat sensitive magnetic contrast agent. The ligands were labelled to carry both a magnetic contrast agent integrated in a heat sensitive cargo and a fluorescent maker. Upon i.v. administration, the manipulated microglia cells and the molecular ligand constructs targeted respectively, in vivo the tumour sites and the inflammatory alterations of lesions of the central nervous system (CNS) under the in vivo control of MRI that was confirmed by immunohistopathology. The approach is developed to associate target specific therapy and biomarkers in CNS diseases. (C) 2011 Elsevier Masson SAS. All rights reserved.

A method based on a seeded growth process was developed to coat ferroelectric nanoparticles with a dielectric silica shell. This method, applied to size-polydispersed (Ba0.6Sr0.4)TiO3 particles (BST, mean diameter 150 nm), allows the control of the silica shell thickness from 2 to 80 nm with an accuracy of 1-2 nm. The morphology and surface physical chemistry of the core-shell were studied by transmission electron microscopy, photon correlation spectroscopy, and zeta potential measurements. A size-sorting procedure consisting of several cycles of centrifugation was optimized to extract the BST@silica nanoparticles of the required size for dielectric properties tuning. Upon sinted ng, dielectric measurements showed that the ferroelectric transition was maintained in the dense nanocomposites.