A dual-targeting fluorescent probe for simultaneous and discriminative visualization of lipid droplets and endoplasmic reticulum

Abstract

A single fluorescent probe (SF-probe) that can simultaneously and discriminatively visualize two organelles is a powerful tool to investigate their interaction in cellular processes.

A Lipid Droplet-Specific NIR Fluorescent Probe with a Large Stokes Shift for In Vivo Visualization of Polarity in Contrast-Induced Acute Kidney Injury

“…Fluorescence imaging is a noninvasive, highly sensitive, superior spatiotemporal, and promising method for the in situ and real-time detection of various bioactive molecules in living systems to perceive the onset and progress of diseases at subcellular and in vivo levels. − To date, albeit dozens of fluorescent probes have been devised for specific monitoring and imaging LDs, subtle polarity-sensitive and near-infrared (NIR, >650 nm) fluorescent probes with a larger Stokes shift (>50 nm) are still scarce, which impedes our insight into the intrinsic relationship between LD polarity and disease. NIR emission has been a research focus in the field of fluorescent probe design due to their excellent properties of high tissue/ in vivo penetration capability, remarkable antibackground interference, and low phototoxicity. − In addition, a larger Stokes shift on fluorescent probes is a desirable characteristic, which can greatly reduce self-absorption and minimize the background fluorescence . Besides, the existing LD-specific polarity probes might be also constrained by one or more of the following drawbacks, including the complex multistep synthetic processes, complex structure, tedious synthesis, low sensitivity, and small Stokes shift.…”

Imino Phenolic Benzene‐1,3,5‐tricarbohydrazide Conjugate as a AIEgen‐Based Fluorescent Probe for the Detection and Bioimaging of Lipid Droplets in Living Cells**

“…Earlier it was impractical to detect lipid droplets properly, but the use of fluorescence microscopy made the identification easier. Besides microscopy, mass spectrometry can also be used to identify lipid droplet proteome [13] nevertheless fluorescence‐based microscopy methods are widely used as they are highly sensitive, quick and provides super‐resolution images to be analyzed [14–17] . Although there are several imaging agents available in the market for the identification of lipid droplets through microscopic techniques such as Nile Red, BODIPY and Oil Red O [18–20] .…”

“…Besides microscopy, mass spectrometry can also be used to identify lipid droplet proteome [13] never-theless fluorescence-based microscopy methods are widely used as they are highly sensitive, quick and provides superresolution images to be analyzed. [14][15][16][17] Although there are several imaging agents available in the market for the identification of lipid droplets through microscopic techniques such as Nile Red, BODIPY and Oil Red O. [18][19][20] However, most of these suffer from small Stokes shift, aggregation-caused quenching, and strong self-absorbance or combination of one or more of these.…”

Photoactivable AIEgen-based Lipid-Droplet-Specific Drug Delivery Model for Live Cell Imaging and Two-Photon Light-Triggered Anticancer Drug Delivery

“…Lipid droplets (LDs) are unique organelles composed of core lipid elements surrounded by an amphipathic lipid layer containing several proteins. − Importantly, the behavior and localization of LDs in cells are closely related to metabolic diseases like obesity, cancer, fatty liver, liver cirrhosis, hyperlipidemia, atherosclerosis, inflammation, and Alzheimer’s. − Recent findings indicate that tumor progression is inextricably linked to LDs, with a higher content of LDs or LD-related proteins observed in cancer cells than in normal cells. , For example, a large number of LDs are found in renal cancers, specifically clear cell renal cell carcinoma, prostate cancer, pancreatic cancer, and colon cancer. − Hence, the tracking and imaging of intracellular LDs are of significant importance for early cancer diagnosis. Several LD probes based on fluorophores, including Nile Red, BODIPY, AIEgens (Aggregation-Induced Emission luminogens), azafluorenone, benzothiadiazole, triphenylamine conjugate with bromobenzylidene (TPA-BI), and Stato-merocyanine, were recently developed. − However, only monitoring the LDs in the live cancer cells is not a solution for cancer ablation . It requires an on-site spatiotemporally controlled delivery of anticancer drugs.…”

“…14−19 However, only monitoring the LDs in the live cancer cells is not a solution for cancer ablation. 20 It requires an on-site spatiotemporally controlled delivery of anticancer drugs. Recently, near-infrared light-responsive drug delivery systems (DDSs) operated in the "phototherapeutic window" (600−950 nm) via a two-photon process for cancer treatment have emerged as a powerful tool.…”