BibTex format
@article{Wells:2026:10.1039/d6tb01037g,
author = {Wells, CJR and Rizk, MMI and Manning, JRH and Winning, D and Brambila, C and Brougham, DF and Carniato, F and Botta, M and Wilton-Ely, JDET and Davies, G-L},
doi = {10.1039/d6tb01037g},
journal = {Journal of Materials Chemistry B},
title = {Exploring the influence of internal surface modification of paramagnetic mesoporous silica nanoparticles on MRI relaxation dynamics},
url = {http://dx.doi.org/10.1039/d6tb01037g},
year = {2026}
}
RIS format (EndNote, RefMan)
TY - JOUR
AB - Paramagnetic mesoporous silica nanoparticles (MSNs) containing immobilised Gd3+-macrocycles are widely investigated as platforms for enhancing magnetic resonance imaging (MRI) contrast, yet the influence of the local chemical surface environment on relaxation dynamics remains underexplored. In this work, we systematically examine how internal surface functionalisation modulates the relaxometric behaviour of Gd3+-chelate modified MSNs. Monodisperse MSNs were prepared with constant Gd3+ loading and varying either proximal thiol or phenyl groups. Thiol-functionalised particles exhibited a clear enhancement in relaxivity with high thiol grafting densities. Fast field-cycling NMR fitting parameters indicated that thiols progressively restrict local rotational dynamics, likely due to changes in local viscosity inside pores coupled with changes in the hydration layer structure around the Gd3+-chelate, reaching a plateau once the grafting density exceeds the density of Gd3+-chelates. In contrast, phenyl groups produce relaxivity enhancement through steric restrictions and hydrophobic crowding that limit chelate motion. Variable-temperature studies confirm that relaxation is dominated by local rotational dynamics rather than water exchange in both cases. These findings demonstrate that different surface modifiers enhance MRI performance via distinct mechanisms, highlighting internal surface chemistry as a key consideration in the design of nanoparticulate contrast agents.
AU - Wells,CJR
AU - Rizk,MMI
AU - Manning,JRH
AU - Winning,D
AU - Brambila,C
AU - Brougham,DF
AU - Carniato,F
AU - Botta,M
AU - Wilton-Ely,JDET
AU - Davies,G-L
DO - 10.1039/d6tb01037g
PY - 2026///
SN - 2050-750X
TI - Exploring the influence of internal surface modification of paramagnetic mesoporous silica nanoparticles on MRI relaxation dynamics
T2 - Journal of Materials Chemistry B
UR - http://dx.doi.org/10.1039/d6tb01037g
UR - https://doi.org/10.1039/d6tb01037g
ER -
