Visualization of drug release in vivo is crucial for improving therapeutic efficacy and preventing inappropriate medication dosing, yet, challenging. Herein, we report a pH-activated chemo-immunotherapy nanoplatform with visualization of drug release in vivo by ratiometric 19F magnetic resonance imaging (19F MRI). This nanoplatform consists of ultra-small histamine-modified perfluoro-15-crown-5-ether (PFCE) nanodroplets loaded with doxorubicin (Dox), which is packaged in trifluoromethyl-containing metal-organic assemblies via coordination-driven self-assembly. The chemical shifts of two types of 19F atoms in the nanoplatform are significantly different in 19F nuclear magnetic resonance (NMR) spectra, which facilitates the implementation of ratiometric 19F MRI without any signal crosstalk. Under an acidic tumor microenvironment, this nanoplatform gradually degrades, which results in a sustained drug release with a real-time change in the ratiometric 19F MRI signal. Therefore, a linear correlation between the Dox release profile and ratiometric 19F MRI signal is established to visualize Dox release. Moreover, the pH-triggered disassembly of the nanoplatform leads to cell pyroptosis, which evokes immunogenic cell death (ICD), resulting in the regression of the primary tumor and inhibition of distal tumor growth. This study provides the proof-of-concept application of ratiometric 19F MRI to visualize drug release in vivo.

This article is Open Access

Please wait while we load your content... Something went wrong. Try again?