Integrating Fluorinated Polymer and Manganese‐Layered Double Hydroxide Nanoparticles as pH‐activated 19F MRI Agents for Specific and Sensitive Detection of Breast Cancer

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 15; no. 36
• Main Authors: Zhang, Cheng, Li, Li, Han, Felicity Y., Yu, Xinying, Tan, Xiao, Fu, Changkui, Xu, Zhi Ping, Whittaker, Andrew K.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 04.09.2019
• Subjects: activated agents; Aqueous solutions; Breast cancer; contrast agents; Fluorination; fluorine magnetic resonance imaging; Hydroxides; Magnetic resonance imaging; Manganese; Nanoparticles; Nanotechnology; NMR; Nuclear magnetic resonance; paramagnetic relaxation enhancement; Reduction
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201902309

19F magnetic resonance imaging (19F MRI) agents capable of being activated upon interactions with cancer triggers are attracting increasing attention, although challenges still remain for precise and specific detection of cancer tissues. In this study, a novel hybrid 19F MRI agent for pH‐sensitive detection of breast cancer tissues is reported, a composite system designed by conjugating a perfluoropolyether onto the surface of manganese‐incorporated layered double hydroxide (Mn‐LDH@PFPE) nanoparticles. The 19F NMR/MRI signals from aqueous solutions of Mn‐LDH@PFPE nanoparticles are quenched at pH 7.4, but “turned on” following a reduction in pH to below 6.5. This is due to partial dissolution of Mn2+ from the Mn‐LDH nanoparticles and subsequent reduction in the effect of paramagnetic relaxation. Significantly, in vivo experiments reveal that an intense 19F MR signal can be detected only in the breast tumor tissue after intravenous injection of Mn‐LDH@PFPE nanoparticles due to such a specific activation. Thus pH‐activated Mn‐LDH@PFPE nanoparticles are a potential “smart” 19F MRI agent for precise and specific detection of cancer diseases. Fluorinated manganese‐based layered double hydroxide nanoparticles are prepared as pH‐activated 19F MRI agents for specific and sensitive detection of breast cancer cells. The well‐defined nanoparticles can be detected only in breast tumor tissue with negligible 19F MRI signal observed from other organs. The findings have deep implications for the future development of selective “smart” 19F MRI agents.