Open AccessMagnetic Mesoporous Silica Nanorods Loaded with Ceria and Functionalized with Fluorophores for Multimodal Imaging
Author(s) -
Jan Grzelak,
Jaume Gázquez,
Alba Grayston,
Mariana Teles,
Fernando Herranz,
Nerea Roher,
Anna Rosell,
Anna Roig,
Martí Gich
Publication year - 2022
Publication title -
acs applied nano materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.227
H-Index - 29
ISSN - 2574-0970
DOI - 10.1021/acsanm.1c03837
Subject(s) - nanorod , materials science , mesoporous silica , mesoporous material , nanotechnology , biocompatibility , rod , nanocomposite , surface modification , nanoparticle , superparamagnetism , magnetic nanoparticles , chemical engineering , chemistry , organic chemistry , catalysis , magnetization , medicine , alternative medicine , physics , pathology , quantum mechanics , magnetic field , engineering , metallurgy
Multifunctional magnetic nanocomposites based on mesoporous silica have a wide range of potential applications in catalysis, biomedicine, or sensing. Such particles combine responsiveness to external magnetic fields with other functionalities endowed by the agents loaded inside the pores or conjugated to the particle surface. Different applications might benefit from specific particle morphologies. In the case of biomedical applications, mesoporous silica nanospheres have been extensively studied while nanorods, with a more challenging preparation, have attracted much less attention despite the positive impact on the therapeutic performance shown by seminal studies. Here, we report on a sol-gel synthesis of mesoporous rodlike silica particles of two distinct lengths (1.4 and 0.9 μm) and aspect ratios (4.7 and 2.2) using Pluronic P123 as a structure-directing template and rendering ∼1 g of rods per batch. Iron oxide nanoparticles have been synthesized within the pores yielding maghemite (γ-Fe 2 O 3 ) nanocrystals of elongated shape (∼7 nm × 5 nm) with a [110] preferential orientation along the rod axis and a superparamagnetic character. The performance of the rods as T 2 -weighted MRI contrast agents has also been confirmed. In a subsequent step, the mesoporous silica rods were loaded with a cerium compound and their surface was functionalized with fluorophores (fluorescamine and Cyanine5) emitting at λ = 525 and 730 nm, respectively, thus highlighting the possibility of multiple imaging modalities. The biocompatibility of the rods was evaluated in vitro in a zebrafish ( Danio rerio ) liver cell line (ZFL), with results showing that neither long nor short rods with magnetic particles caused cytotoxicity in ZFL cells for concentrations up to 50 μg/ml. We advocate that such nanocomposites can find applications in medical imaging and therapy, where the influence of shape on performance can be also assessed.