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Multicolored pH-tunable and activatable fluorescence nanoplatform responsive to physiologic pH stimuli
Kejin Zhou1, Haoming Liu, Shanrong Zhang
1Department of Pharmacology, Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
Journal of the American Chemical Society
|April 25, 2012
Summary
Researchers developed pH-tunable fluorescent nanoparticles that change color to track cellular processes. These multicolored nanoparticles enable precise monitoring of endocytic trafficking and pH changes within organelles.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Cell Biology
Background:
- Fluorescent nanoparticles are crucial for studying cellular processes like endocytosis and organelle pH.
- Precisely tracking subtle pH changes (<1 pH unit) in endocytic compartments is challenging.
Purpose of the Study:
- To develop a general strategy for creating pH-tunable, multicolored fluorescent nanoparticles with ultra-pH responsiveness.
- To enable precise monitoring of intracellular pH dynamics and endocytic trafficking.
Main Methods:
- Utilized pH-insensitive dyes and pH-induced micellization to create nanoparticles with tunable emissions (green to near-IR).
- Investigated homo Förster resonance energy transfer (homoFRET) as the key mechanism for ultra-pH response.
- Synthesized a panel of nanoparticles with sharp pH transitions (ON/OFF < 0.25 pH unit) at specific pH points (5.2, 6.4, 6.9, 7.2).
Main Results:
- Successfully produced multicolored nanoparticles with emissions spanning 500-820 nm.
- Demonstrated ultra-sharp pH sensitivity, with distinct activation points for each nanoparticle.
- Observed sequential activation of nanoparticles within endocytic compartments of H2009 lung cancer cells, correlating with intracellular pH changes.
Conclusions:
- The developed nanoplatform provides a versatile tool for studying complex cellular pH regulation and endocytic trafficking.
- These multicolored, pH-tunable nanoparticles offer new opportunities for advanced biological imaging and diagnostics.
