Surface engineering of silica nanoparticles with a gadolinium–PCTA complex for efficient T₁-weighted MRI contrast agents

Abstract

Covalent grafting of diaqua Gd(iii)-complexes onto dense silica nanoparticles affords non-toxic contrast agents suitable for high field MRI pre-clinical studies.

Design of Bifunctional Pyclen-Based Lanthanide Luminescent Bioprobes for Targeted Two-Photon Imaging

“…The pyridine unit has also been used to design lipophilic contrast agents for atherosclerosis PET imaging such as [ 68 Ga­(PCTA)]-DSPE, DSPE being the main constituent of the phospholipid moiety of the High-Density Lipoprotein involved in cardiovascular diseases . The para -functionalization of PCTA with hydroxyl, carboxylic acid, or amino groups has been widely investigated by Picard et al As a proof of concept, the authors grafted a cholecystokinin tetrapeptide CCK4 or biotin at the para -position of PCTA . In 2020, Green also synthesized pyclen derivatives para -functionalized with electron-withdrawing groups such as para -cyano, chloro, nitro, or CF 3 derivatives …”

Fundamental understanding of the size and surface modification effects on r1, the relaxivity of Prussian blue nanocube@m-SiO2: a novel targeted chemo-photodynamic theranostic agent to treat colon cancer

“…11 In this context, it may be stated that mostly Gd 3+ based chelating agents, namely DOTAREM® and MAGNEVIST®, are nowadays used at a dose of 10 to 20 mL of 0.5 mM solution depending on the body weight; besides, it also has serious side effects such as gadolinium toxicity and nephrogenic systemic brosis. 12,13 Herein, the current research effort focuses on improving the effectiveness of CA in order to be able to reduce the dose of administration of CA with very mild side effects. Concerning, PB, which is being used as the sole U.S. Food and Drug Administration approved T 1 -weighted CA for MRI has the advantage of a high signal-to-noise ratio, fast scanning, bright eld image, etc.…”

Functionalized silica nanoplatform as a bimodal contrast agent for MRI and optical imaging

“…11,[19][20][21] More specifically, silica NPs (SiO 2 -NPs) appear to be particularly interesting supports because they offer many advantages over other nanosystems, such as tunable and welldefined structures in terms of size, morphology and porosity. 11,22 In addition, their biocompatibility, 12,23,24 ease of surface modification, [25][26][27][28][29][30][31] and possibility of entrapping molecules in their cores render SiO 2 -NPs particularly valuable materials for biomedical purposes. 11,25,[32][33][34][35][36] If most of the systems using silica as a matrix proposed the covalent grafting of Gd-chelates onto the surface of porous particles, the use of amorphous silica for the noncovalent confinement of Gd complexes has been poorly studied despite the fact that such a strategy frees up the surface for other molecules of interest (e.g., peptides, antibodies, siRNA, …).…”