A Kyushu University team has created water-soluble, metal-free molecules capable of functioning as both fluorescence imaging agents and MRI contrast agents.
Key facts
- •The new molecules, TTM-trisTP3B and TTM-trisTP9B, produce deep-red fluorescence in water.
- •The molecules eliminate the need for paramagnetic metals like gadolinium in MRI contrast agents.
- •TTM-trisTP3B demonstrated stable fluorescence in living cells for at least 24 hours.
- •The molecules improved MRI phantom image contrast by 2.5 to 4.5 times compared to earlier water-soluble TTM radicals.
- •The research was led by associate professor Ken Albrecht at Kyushu University.
A research team led by Kyushu University has developed new water-soluble, metal-free molecules that can be detected by fluorescence imaging and used as MRI contrast agents. Published in the journal Advanced Science, the study introduces a potential alternative to traditional MRI contrast agents, which often rely on paramagnetic metals like gadolinium that can cause adverse side effects.
By the numbers
Overcoming Imaging Limitations
Fluorescence imaging (FI) and magnetic resonance imaging (MRI) are standard clinical and research tools, yet both have inherent limitations. FI offers high-resolution visualization of cells but lacks depth, while MRI captures deep-body images but lacks single-cell resolution. By combining these functionalities into a single molecule, researchers aim to create safer, multifunctional imaging agents.
Development of TTM-based Molecules
The team focused on luminescent organic radicals, specifically a molecule called tris(2,4,6-trichlorophenyl) methyl (TTM). While TTM is known for producing fluorescence and molecular spin, previous versions were hydrophobic, making them difficult to use in biological systems. The researchers optimized the molecule by binding it to water-soluble groups in three directions, resulting in two new variants: TTM-trisTP3B and TTM-trisTP9B.
Testing and Future Applications
In tests, TTM-trisTP3B emitted fluorescence around the cell nucleus in living cells for at least 24 hours. Both new molecules enhanced MRI phantom image contrast by approximately 2.5 to 4.5 times more than previously reported water-soluble TTM radicals. Associate professor Ken Albrecht noted that while animal studies are required to confirm viability, the results provide a proof of concept for metal-free dual-modal imaging and may contribute to future quantum sensing technologies.
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This article was independently rewritten by ManyPress editorial AI from reporting originally published by Phys.org.
