Supramolecular Assembly with Near-Infrared Emission for Two-Photon Mitochondrial Targeted Imaging

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Biomedical Imaging

Background:

• Tetraphenylethene derivatives (TPE-2SP) show weak fluorescence.
• Supramolecular host-guest chemistry offers tunable optical properties.
• Near-infrared (NIR) fluorescence is crucial for deep tissue imaging.

Purpose of the Study:

• To construct a two-photon supramolecular assembly with enhanced NIR fluorescence.
• To investigate the role of cucurbiturils (CB[7] and CB[8]) in fluorescence enhancement.
• To develop a targeted imaging agent for mitochondria.

Main Methods:

• Synthesis of TPE-2SP derivative.
• Supramolecular complexation with cucurbit[7]uril (CB[7]) and cucurbit[8]uril (CB[8]).
• Assembly with hyaluronic acid-conjugated β-cyclodextrin (HA-CD) to form nanoparticles.
• Characterization of fluorescence properties and two-photon absorption.
• Evaluation of mitochondrial targeting and imaging in vitro.

Main Results:

• TPE-2SP fluorescence was enhanced upon complexation with CB[7] and CB[8].
• CB[8] assembly led to a redshifted NIR emission (30 nm) and increased intensity.
• Self-assembly into nanoparticles with HA-CD further enhanced NIR luminescence.
• The nanoparticles exhibited two-photon absorption and targeted mitochondria.

Conclusions:

• A novel two-photon supramolecular system with enhanced NIR emission was successfully constructed.
• The system demonstrates potential for targeted biological imaging, particularly for mitochondria.
• This approach offers a new strategy for developing advanced biomedical imaging agents.