Viscosity-Sensitive Solvatochromic Fluorescent Probes for Lipid Droplets Staining

Abstract

Lipid droplets (LDs) are simple intracellular storage sites for neutral lipids and exhibit important impact on many physiological processes. For example, the changes in the polar microenvironment inside LDs could affect physiological processes, such as lipid metabolism and storage, protein degradation, signal transduction, and enzyme catalysis. Herein, a new fluorescent chemo-sensor (Couoxo-LD) was formulated by our molecular design strategy. The probe could be applied to effectively label intracellular lipid droplets. Intriguingly, Couoxo-LD demonstrated positive sensitivity to both polarity and viscosity, which might be attributed to its D-π-A structure and the twisted rotational behavior of the carbon–carbon double bond (TICT). Additionally, Couoxo-LD was successfully implemented in cellular imaging due to its excellent selectivity, pH stability, and low biotoxicity. In HeLa cells, the co-localization curve between Couoxo-LD and commercial lipid droplet dyes overlapped at 0.93. The results indicated that the probe could selectively sense LDs in HeLa cells. Meanwhile, Couoxo-LD can be applied for in vivo imaging of zebrafish.

A Single Organic Fluorescent Probe for the Discrimination of Dual Spontaneous ROS in Living Organisms: Theoretical Approach

“…F. Goppelsroder built a fluorescent sensor that was used for the detection of Al 3+ through fluorescence enhanced after chelate formation from mulberry pigment dye with the Al 3+ ligand. Afterwards, a large number of fluorescent probes for the detection of different kinds of targets were developed [4][5][6][7][8][9][10][11][12][13]. Nowadays, fluorescent probes based on small organic molecules have been widely expanded in food detection, environmental monitoring, clinical examination, and many other fields.…”

Theoretical Insights into a Near-Infrared Fluorescent Probe NI-VIS Based on the Organic Molecule for Monitoring Intracellular Viscosity

“…Cell micro viscosity plays an important role in various biological processes, such as mass and energy transfer, signal transduction, interaction between biological macromolecules (proteins), active enzymes and cell metabolic rate, etc. [ 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Therefore, the design and synthesis of effective fluorescent probes for the determination of cell viscosity is of great significance for the study of cell physiological and pathological processes.…”

“…Therefore, the design and synthesis of effective fluorescent probes for the determination of cell viscosity is of great significance for the study of cell physiological and pathological processes. So far, many fluorescence probes for the detection of viscosity have been reported in the literature [ 11 , 12 , 14 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ].…”

Polarity-Driven Two-Photon Fluorescent Probe for Monitoring the Perturbation in Lipid Droplet Levels during Mitochondrial Dysfunction and Acute Pancreatitis

“…The fluorescence-based molecular probes become emerging tools to provide dynamic information on the local cellular microenvironments such as viscosity, polarity, lipid order, and so forth. − Various strategic fluorescent probes such as rotors, flippers, solvatochromic and push–pull dyes have been employed for detecting LDs in live cells as well as in vivo . Among them, the solvatochromic fluorescent probes show ultrasensitivity toward the order of the LDs and apolar entities. − …”