resumo
We report the fine-tuning of the relaxometry of gamma-Fe2O3@SiO2 core-shell nanoparticles by adjusting the thickness of the coated silica layer. It is clear that the coating thickness of gamma Fe2O3@SiO2 nanoparticles has a significant impact on the r(1) (at low B-0 fields), r(2), and r(2)* relaxivities of their aqueous suspensions. These studies clearly indicate that the silica layer is heterogeneous and has regions that are porous to water and others that are not. It is also shown, that the viability and the mitochondrial dehydrogenase expression of the microglial cells do not appear to be sensitive to the vesicular load with these core shell nanoparticles. The adequate silica shell thickness can therefore be tuned to allow for both a sufficiently high response as contrast agent, and adequate grafting of targeted biomolecules.
palavras-chave
IRON-OXIDE NANOPARTICLES; CDSE/CDS CORE/SHELL NANOCRYSTALS; NMR TRANSVERSAL RELAXIVITY; SEMICONDUCTOR QUANTUM DOTS; MAGNETIC NANOPARTICLES; FE3O4 NANOPARTICLES; CONTROLLED GROWTH; CONTRAST AGENTS; PARTICLES; CELLS
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Pinho, SLC; Pereira, GA; Voisin, P; Kassem, J; Bouchaud, V; Etienne, L; Peters, JA; Carlos, LD; Mornet, S; Geraldes, CFGC; Rocha, J; Delville, MH
nossos autores
João Rocha
Prof. Catedrático
Luís Carlos
Professor CatedráticoProjectos
Nanostructured Photoluminescent rare-earth nanotubes and microporous silicates (PTDC/CTM/73243/2006)
Functionalised Advanced Materials and Engineering of Hybrids and Ceramics - FAME (FAME)
agradecimentos
This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT), Portugal (grants to SLCP (SFRH/BD/38313/2007), GAP (SFRH/BPD/35005/2007), and project PTDC/CTM/73243/2006), the CNRS France, the Region Aquitaine France, FEDER, COST Action D38