New carboxysilane‐coated iron oxide nanoparticles for nonspecific cell labelling

This study reports the synthesis at the gram scale of iron oxide nanoparticles as MRI T2 contrast agents for cell labelling. These NPs are based on small iron oxide cores coated with a thin polysiloxane shell presenting carboxylic acid functions. The iron oxide cores produced have been characterized by transmission electron microscopy, X‐ray diffraction, ζ‐potential, infrared, photon correlation spectroscopy, atomic force microscopy, magnetometry and relaxometric measurements. These measurements confirmed the expected surface modification by carboxysilane. Carboxylic groups created electrostatic repulsion between NPs when they are deprotonated. Therefore, highly concentrated aqueous solutions of carboxysilane coated iron oxide NPs can be obtained, up to 70% (w/w). These NPs could be used for cell labelling owing to their aggregation and re‐dispersion properties. NPs precipitated in Dulbecco's modified Eagle medium induced a rapid association with 3 T6 fibroblast cells and could easily be re‐dispersed in phosphate buffer saline solution to obtain properly labelled cells. Copyright © 2013 John Wiley & Sons, Ltd. This study reports the synthesis of iron oxide nanoparticles coated by triethoxysilanepropylsuccinic acid that exhibit exceptional stability in aqueous solution. Because of an efficient electrostatic repulsion, solutions up to 70% (wt) can be produced and manipulated as magnetic fluids. Moreover, nanoparticles coated with carboxysilane are rapidly intern...
Source: Contrast Media and Molecular Imaging - Category: Radiology Authors: Tags: Full Paper Source Type: research