One-Step Synthesis of Single-Stranded DNA-Bridged Iron Oxide Supraparticles as MRI Contrast Agents

Zhang, JF (Zhang, Jingfang)^{[ 1,2,3 ]} ; Di, ZH (Di, Zhenghan)^{[ 2,3,4 ]} ; Yan, HS (Yan, Husheng)^{[ 1 ]} ; Zhao, YL (Zhao, Yuliang)^{[ 2,3,4 ]} ; Li, LL (Li, Lele)^{[ 2,3,4 ]}

NANO LETTERS, 2021, 21(7): 2793-2799

DOI: 10.1021/acs.nanolett.0c04825

摘要

Despite progress on DNA-assembled nanoparticle (NP) superstructures, their complicated synthesis procedures hamper their potential biomedical applications. Here, we present an exceptionally simple strategy for the synthesis of single-stranded DNA (ssDNA) assembled Fe3O4 supraparticles (DFe-SPs) as magnetic resonance contrast agents. Unlike traditional approaches that assemble DNA-conjugated NPs via Watson-Crick hybridization, our DFe-SPs are formed with a high yield through one-step synthesis and assembly of ultrasmall Fe3O4 NPs via ssDNA-metal coordination bridges. We demonstrate that the DFe-SPs can efficiently accumulate into tumors for sensitive MR imaging. By virtue of reversible DNA-metal coordination bridges, the DFe-SPs could be disassembled into isolated small NPs in vivo, facilitating their elimination from the body. This work opens a new avenue for the ssDNA-mediated synthesis of superstructures, which expands the repertoire of DNA-directed NP assembly for biomedical applications.