Effect of the Functionalization Process on the Colloidal, Magnetic Resonance Imaging, and Bioelimination Properties of Mono‐ or Bisphosphonate‐Anchored Dendronized Iron Oxide Nanoparticles

Abstract

The functionalization process of iron oxide nanoparticles (NPs) is a major step and has to ensure a small particle size distribution (below 100 nm) and to preserve good magnetic properties suitable for in vivo applications. Two functionalization processes are here compared to coat iron oxide NPs, synthesized by thermal decomposition, with dendron molecules bearing either a mono‐ or a bisphosphonate anchoring group. The two processes are direct ligand exchange and the simultaneous ligand exchange and phase transfer process. The latter process led to a larger size distribution than the former. The phosphonate group is confirmed to be a strong anchoring agent from X‐ray photoelectron spectroscopy (XPS) and IR characterizations whatever the grafting process and the number of phosphonate groups, it also confirms the preservation of the NPs’ magnetic properties. All dendronized NPs display good in vitro MRI properties and those obtained by direct exchange showed no cell internalization, an efficient in vivo MRI contrast enhancement, and elimination by both urinary and hepato‐biliary ways.

Assessing the parameters modulating optical losses of iron oxide nanoparticles under near infrared irradiation

“…[47][48][49][50] IONPs were transferred to aqueous media following a well-established protocol. 49,51,52 The resulting IONPs were coated with dendrons bearing phosphonic acid tweezers and three PEG chains for biocompatibility to ensure a strong coupling to the IONP surface. Finally, two commercial IONPs were used: i) FluidMag-CT (FM-CT; product number: 4122-1) are manufactured by Chemicell GmbH (Berlin, Germany); ii) HyperMAG C (LRL) are manufactured by Liquids Research Limited (Bangor, United Kingdom).…”

Dendron based antifouling, MRI and magnetic hyperthermia properties of different shaped iron oxide nanoparticles

“…Syntheses of iron oxide NPs with various shapes and coated with oleic acid (OA) was achieved according to previously reported procedures [47]. Also, the synthesis procedure of the dendron molecule can be found in [18,34,50]. Functionalization of the NPs by the dendron molecules is performed through a direct grafting process.…”

“…avoiding RES uptake. Recent in vitro and in vivo results with 10 nm sized spherical NPs confirmed that they do not internalize in cells and accumulate in organs after IV injection [17,18,24].…”

Monocorevs.multicore magnetic iron oxide nanoparticles: uptake by glioblastoma cells and efficiency for magnetic hyperthermia

“…Phosphonates and bis-phosphonates were already used as chain end-groups for IONP pegylation. 17 In previous reports studying stealth IONPs in vitro or in vivo, phosphonic acid anchors were rather grafted along the polymer backbone, either in a block structure with PEG 18,19 or as a statistical copolymer with PEG sidechains. 20 Other types of anchoring moieties are also used for IONP pegylation, like nitrodopamine 21 or silanes 22,23 .…”