The epsilon-AlxFe2-xO3 nanomagnets as MRI contrast agents: Factors influencing transverse relaxivity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11110%2F20%3A10420898" target="_blank" >RIV/00216208:11110/20:10420898 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/20:10420898

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=FJ9QhW4U43" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=FJ9QhW4U43</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.colsurfa.2020.124423" target="_blank" >10.1016/j.colsurfa.2020.124423</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The epsilon-AlxFe2-xO3 nanomagnets as MRI contrast agents: Factors influencing transverse relaxivity

Popis výsledku v původním jazyce

Most magnetic materials studied as negative contrast agents for magnetic resonance imaging (MRI) enter the superparamagnetic state with decreasing size of their particles, which is distinguished by thermal fluctuations of particle magnetic moment. In the present study, a novel type of contrast agents based on non-superparamagnetic nanoparticles (nanomagnets) of aluminum-doped epsilon polymorph of Fe2O3 is suggested and used as a model system to elucidate the role of magnetic blocking and other factors in the transverse relaxation of water. Specifically, the dependence of the transverse relaxivity r(2) on the magnetic field (0.47-11.75 T), temperature (278 - 348 K), magnetization, surface modification (silica or citrate) and thickness of silica coating (6 - 21 nm) is analyzed for the epsilon-AlxFe2-xO3 nanoparticles with x = 0.23 and the median size of 21 nm. These nanoparticles evinced higher magnetization than the undoped material and were in the blocked state in the temperature range under study. Further, irreversible magnetization processes were revealed by SQUID magnetometry in aqueous suspension of coated clusters of magnetic crystallites that resulted in the field dependence of r(2). The temperature dependence of r(2) was interpreted by the combination of two different regimes - motional averaging and static dephasing regimes. Slow diffusion of water molecules inside the silica shells was suggested to explain only moderate decrease of r(2) with increasing the coating thickness. Moreover, the performance of the contrast agent was demonstrated not only in ultra-high-field MRI at 11.75 T but also by imaging in vivo on a mouse model at 1 T. Finally, preliminary evaluation of cytotoxicity on rat mesenchymal stem cells did not reveal any significant effects. Due to their low toxicity and high relaxivity, epsilon-AlxFe2-xO3 nanoparticles present a promising starting material for further biomedical applications involving MRI, multimodal contrast agents and theranostic carriers.

Název v anglickém jazyce

The epsilon-AlxFe2-xO3 nanomagnets as MRI contrast agents: Factors influencing transverse relaxivity

Popis výsledku anglicky

Most magnetic materials studied as negative contrast agents for magnetic resonance imaging (MRI) enter the superparamagnetic state with decreasing size of their particles, which is distinguished by thermal fluctuations of particle magnetic moment. In the present study, a novel type of contrast agents based on non-superparamagnetic nanoparticles (nanomagnets) of aluminum-doped epsilon polymorph of Fe2O3 is suggested and used as a model system to elucidate the role of magnetic blocking and other factors in the transverse relaxation of water. Specifically, the dependence of the transverse relaxivity r(2) on the magnetic field (0.47-11.75 T), temperature (278 - 348 K), magnetization, surface modification (silica or citrate) and thickness of silica coating (6 - 21 nm) is analyzed for the epsilon-AlxFe2-xO3 nanoparticles with x = 0.23 and the median size of 21 nm. These nanoparticles evinced higher magnetization than the undoped material and were in the blocked state in the temperature range under study. Further, irreversible magnetization processes were revealed by SQUID magnetometry in aqueous suspension of coated clusters of magnetic crystallites that resulted in the field dependence of r(2). The temperature dependence of r(2) was interpreted by the combination of two different regimes - motional averaging and static dephasing regimes. Slow diffusion of water molecules inside the silica shells was suggested to explain only moderate decrease of r(2) with increasing the coating thickness. Moreover, the performance of the contrast agent was demonstrated not only in ultra-high-field MRI at 11.75 T but also by imaging in vivo on a mouse model at 1 T. Finally, preliminary evaluation of cytotoxicity on rat mesenchymal stem cells did not reveal any significant effects. Due to their low toxicity and high relaxivity, epsilon-AlxFe2-xO3 nanoparticles present a promising starting material for further biomedical applications involving MRI, multimodal contrast agents and theranostic carriers.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/GA19-02584S" target="_blank" >GA19-02584S: Modifikace néelovských a brownovských relaxačních vlastností nanočástic pro magnetické zobrazovací metody</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Colloids and Surfaces A: Physicochemical and Engineering Aspects

ISSN

0927-7757

e-ISSN

—

Svazek periodika

589

Číslo periodika v rámci svazku

2020

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

11

Strana od-do

124423

Kód UT WoS článku

000513861400023

EID výsledku v databázi Scopus

2-s2.0-85077507452