Development of superparamagnetic nanoparticles for MRI: effect of particle size, charge and surface nature on biodistribution

Abstract

Twelve superparamagnetic Magnetite-Dextran (MD) nanoparticles potentially useful as contrast agents for Magnetic Resonance Imaging (MRI), with different sizes, charges and surface natures, were produced and internally labelled with (59)Fe in order to investigate the effect of their physicochemical properties on their biodistribution in mice. In a first step, neutral MD particles of a size 33-90.6 nm were studied. Next, the influence of charge was investigated with negative and positive particles (MDL, MDD, MDDEAE). The former (-25, -30 mV) were small, around 30 nm in size whereas the latter (+20 mV) were larger (104 nm). The effect of surface nature was evaluated using MD particles coated with polyoxyethylene-polyoxypropylene copolymers (Synperonic: these MDP particles were neutral and larger in size (65.9-76.4 nm). Experiments showed that 20 min post-injection (2 mg Fe/kg), liver uptake was enhanced when the mean diameter increased: 22% for the smallest and 42% for the largest. It was up to 3 X lower for electrically neutral particles than for charged particles. Coated particles presented higher vascular persistence. The diagnostic potential for liver, lymph node or vascular imaging were discussed.

A new procedure for preparation of polyethylene glycol-grafted magnetic iron oxide nanoparticles

“…Briefly, under N 2 purging, 1 g of FeCl 2 .4H 2 O and 2.6 g of FeCl 3 .6H 2 O were dissolved in 25 ml distilled water and kept at 75°C for 10 min, then 10 mL of ammonia solution (25 %) was dropped into the above mixture under vigorous stirring and keeping at 75°C for a further 1.5 h. The resulting suspension was washed with distilled water and ethanol three times and dried under vacuum.…”

“…Modified mPEG and surface of MNPs were characterized by FT-IR spectroscopy (Bruker-Equinoxss) and nuclear magnetic resonance ( 1 HNMR) (Bruker, 500 MHz) in CDCl 3 . The obtained nanoparticles were analyzed by scanning electron microscopy (HITACHI S 4160).…”

“…Magnetic iron oxide nanoparticles with tailored surface chemistry have been widely used experimentally for numerous in vivo applications such as magnetic resonance imaging, contrast enhancement, tissue repair, immunoassay, detoxification of biological fluids, hyperthermia, drug delivery and in cell separation [1][2][3][4][5]. Coating or modifying these nanoparticles with hydrophilic molecules, especially biomolecules, is a crucial step for the preparation of waterdispersible magnetite nanoparticles (MNPs) for use in biological applications [6].…”

Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications

“…[4] To inhibit nanoparticles agglomeration and adsorption of plasma protein to the surface of hydrophobic nanoparticles, they have to be equipped with protein-repellent surface to prevent recognition by the RES and extend circulation time in the body. [429] This has led to the development of stealth nanoparticles which are a promising tool for avoiding their elimination by the body's defense system.…”

Revolutionary Impact of Nanodrug Delivery on Neuroscience

“…Magnetic properties and internalisation of particles in cells depend strongly on the size of the magnetic particles. Particles below 100 nm are small enough both to evade reticuloendothelial system (RES) of the body as well as penetrate the very small capillaries within the body tissues [195, 196]. Because of their hydrophobic surfaces and large surface area to volume ratio, in vivo use of nanoparticles is hampered by very rapid clearance of nanoparticles from the circulation by the RES.…”