Mitochondria Targeted Nanoscale Zeolitic Imidazole Framework-90 for ATP Imaging in Live Cells

Abstract

Zeolitic imidazole frameworks (ZIFs) are an emerging class of functional porous materials with promising biomedical applications such as molecular sensing and intracellular drug delivery. We report herein the first example of using nanoscale ZIFs (i.e., ZIF-90), self-assembled from Zn and imidazole-2-carboxyaldehyde, to target subcellular mitochondria and image dynamics of mitochondrial ATP in live cells. Encapsulation of fluorescent Rhodamine B (RhB) into ZIF-90 suppresses the emission of RhB, while the competitive coordination between ATP and the metal node of ZIF-90 dissembles ZIFs, resulting in the release of RhB for ATP sensing. With this method, we are able to image mitochondrial ATP in live cells and study the ATP level fluctuation in cellular glycolysis and apoptosis processes. The strategy reported here could be further extended to tune nanoscale ZIFs inside live cells for targeted delivery of therapeutics to subcellular organelles for advanced biomedical applications.

Metal–Organic Frameworks for Biomedical Applications

“…As a universally used imaging method, FL has been employed to acquire visualized information of the biological distribution and content via optical molecules, which has the advantages of high sensitivity, excellent resolution, and facile operation. Mao and co‐workers constructed a simple MOF‐based fluorescent probe, consisting of Zn 2+ and imidazole‐2‐carboxyaldehyde ligands, namely RhB/ZIF‐90, for FL of mitochondria adenosine triphosphate (ATP) in living cells 43. Rhodamine (RhB) was encapsulated into ZIF‐90, and its fluorescence was quenched due to the self‐quenching effect.…”

Proximity hybridization triggered strand displacement and DNAzyme assisted strand recycling for ATP fluorescence detection in vitro and imaging in living cells

“…Sample 2: S1/S3 (1.5 mL, 50 mM), S2 (1.5 mL, 100 mM), S4 (1.5 mL, 100 mM) were mixed with ATP (1.5 mL 10 mM) and Pb(AC) 2 (0.5 mL 10 mM) at 37 C for 80 min.…”

Self‐Mineralized Photothermal Bacteria Hybridizing with Mitochondria‐Targeted Metal–Organic Frameworks for Augmenting Photothermal Tumor Therapy

“…Thus, interfering mitochondrial functions could both metabolically and genetically intervene the heat tolerance of cancer cells. Metal‐organic framework (MOF) of zeolitic imidazole frameworks‐90 (ZIF‐90), forming from the coordination of imidazolate‐2‐carboxaldehyde (2‐ICA) and Zn 2+ , can selectively release cargos in mitochondria through ATP induced host frameworks collapse 21. ZIF‐90 may be suitable to serve as mitochondria‐targeted drug carrier for mitochondria interference.…”

“…In order to enhance the PTT efficacy of PTB, photosensitizer methylene blue (MB) loaded ZIF‐90 (ZIF‐90/MB) was further synthesized and conjugated on the surface of PTB to obtain PTB@ZIF‐90/MB via acid‐sensitive imine bond. Upon PTB@ZIF‐90/MB arriving at acidic tumor site, ZIF‐90/MB could fall off from PTB surface and selectively release MB at mitochondria due to ATP‐induced degradation of ZIF‐90 host frameworks 21. MB can generate reactive oxygen species (ROS) of singlet oxygen ( 1 O 2 ) under light illumination.…”