A Red-Emitting Fluorescence Sensor for Detecting Boronic Acid-Containing Agents in Cells

Area of Science:

• Chemical Biology
• Medical Imaging
• Nanotechnology

Background:

• Boron neutron capture therapy (BNCT) efficacy relies on precise boron-10 atom delivery into tumor cells.
• Existing fluorescence sensors for intracellular boronic acids emit blue light, hindering co-staining with nuclear markers like DAPI.
• Developing novel sensors is crucial for accurate assessment of BNCT agents.

Purpose of the Study:

• To design and synthesize a novel red-emitting fluorescence boron sensor, BS-631.
• To evaluate BS-631's ability to detect and visualize intracellular boronic acid compounds, specifically 4-borono-l-phenylalanine (BPA).
• To assess BS-631's compatibility with nuclear staining reagents for enhanced cellular imaging.

Main Methods:

• Synthesis of the novel fluorescence boron sensor, BS-631.
• Characterization of BS-631's fluorescence emission wavelength (λmax = 631 nm).
• Quantitative detection of BPA using BS-631 and assessment of its detection limit.
• Evaluation of BS-631's selectivity against metal cations.
• Cellular imaging experiments co-staining with Hoechst 33342.

Main Results:

• BS-631 was successfully synthesized and exhibited red fluorescence emission at 631 nm.
• BS-631 quantitatively detected BPA with a sensitive detection limit of 19.6 µM.
• The sensor showed no fluorescence in the presence of metal cations, indicating high selectivity.
• BS-631 enabled clear visualization of BPA localization within cells, even when co-stained with Hoechst 33342.

Conclusions:

• BS-631 is a novel, red-emitting fluorescence sensor effective for detecting and localizing boronic acid agents like BPA.
• Its ability to co-stain with nuclear markers overcomes limitations of existing blue-emitting sensors.
• BS-631 shows significant promise as a versatile tool for evaluating and analyzing BNCT agents in cancer research and therapy.