Clustered ultra-small iron oxide nanoparticles as potential T 1 /T 2 dual-modal magnetic resonance imaging contrast agents and application to tumor model

• Published in: Nanotechnology 2024-12, Vol.35 (50), p.505101
• Main Authors: Liu, Ying, Ho, Son Long, Tegafaw, Tirusew, Zhao, Dejun, Ahmad, Mohammad Yaseen, Ali Al Saidi, Abdullah Khamis, Cha, Hyunsil, Lee, Sangyeol, Lee, Hansol, Kim, Seungho, Han, Mun, Chae, Kwon Seok, Chang, Yongmin, Lee, Gang Ho
• Format: Article
• Language: English
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/ad8203

Many studies have been conducted on the use of ultra-small iron oxide nanoparticles (USIONs) (d < 3 nm) as potential positive magnetic resonance imaging (MRI)-contrast agents (CAs); however, there is dearth of research on clustered USIONs. In this study, nearly monodispersed clustered USIONs were synthesized using a simple two-step one-pot polyol method. First, USIONs (d = 2.7 nm) were synthesized, and clustered USIONs (d = 27.9 nm) were subsequently synthesized through multiple cross-linking of USIONs with poly(acrylic acid-co-maleic acid) (PAAMA) polymers with many -COOH groups. The clustered PAAMA-USIONs exhibited very weak ferromagnetism owing to the magnetic interaction between superparamagnetic USIONs; this was evidenced by their appreciable r = 3.9 s mM and high r /r ratio of 14.6. Their ability to function as a dual-modal T /T MRI-CA in T -weighted MRI was demonstrated when they simultaneously exhibited positive and negative contrasts in T -weighted MRI of tumor model mice after intravenous injection. They displayed positive contrasts at the kidneys, bladder, heart, and aorta and negative contrasts at the liver and tumor.&#xD.