Super-Resolution FLIM Imaging of Intracellular Lipid Microenvironments with a Dual-Responsive Polarity- and...

Area of Science:

• Cell biology
• Biophysics
• Microscopy

Background:

• The cellular microenvironment's physical properties (polarity, pH) are vital for biological functions.
• Understanding these properties requires advanced imaging techniques.
• Existing fluorescent probes for microenvironment analysis are limited.

Purpose of the Study:

• To develop a novel fluorescent probe for real-time, nanoscale visualization of the cellular microenvironment.
• To enable quantitative analysis of intracellular lipid distribution, polarity, and pH.
• To advance the study of cellular biophysical properties using super-resolution microscopy.

Main Methods:

• Development of a novel polarity- and pH-sensitive fluorescent probe (TPA-BT-CA) with a donor-acceptor-acceptor (D-A-A) structure.
• Utilizing stimulated emission depletion fluorescence and lifetime imaging microscopy (STED/FLIM) for super-resolution imaging.
• Real-time imaging and quantitative mapping of intracellular lipid distributions in living cells.

Main Results:

• TPA-BT-CA exhibits high photostability and strong fluorescence signals in nonpolar environments due to efficient intramolecular charge transfer.
• The probe demonstrates prolonged fluorescence lifetimes in nonpolar lipid regions, enabling precise differentiation.
• Fluorescence lifetime shifts under varying pH conditions allow quantitative assessment of lipid distribution.

Conclusions:

• TPA-BT-CA provides a new method for high-resolution visualization and quantitative measurement of the cellular microenvironment.
• This probe offers novel insights into lipid organization and dynamic changes within the cellular environment.
• The study establishes a powerful tool for exploring intracellular biophysical properties with nanoscale precision.