The new dye offers a breakthrough in deep tissue imaging and anti -cancer therapy

Scientists from Tokyo Metropolitan University have developed a new dye that can strongly absorb the second radiation near IR and transform it into heat. Starting from the dye of the bile pigments family, they designed a unique ring structure that can tie ROD and Iridium. Measurements and modeling revealed a strong second absorption of close IR and exceptional photostable. The second waves close to IR easily penetrate into human tissue; The new dye can be used in deep tissue therapies and imaging.

The second region near the electromagnetic spectrum (1000-1700 nanometers) is a potentially important range of wavelength for medical sciences. In this respect, the light is not so much dispersed or absorbed by biological tissue. This transparency makes it ideal for supplying energy to deeper parts of the body, both for imaging and treatment. An important example of such therapy is photoacoustic imaging in cancer diagnosis and treatment. When the contrasting agent injected into the body is hit with light, it emits heat, which causes small ultrasonic shocks, which can be detected for imaging, or for damage to cancer cells.

Effectiveness This approach depends on the availability of stable contrast agents that can effectively absorb light at these wavelengths. However, most contrasting agents are more sensitive in the first range close to IR (700-1000 nanometers), where the scattering effects are stronger and energy supply is less efficient.

Now a team of scientists led by Professor Masatoshi Ichida from Tokyo Metropolitan University has developed a new chemical relationship that overcomes this Achilles heel. Starting from the dye of the bile pigment family called Bilaratriene, they used the method known as the N-Confusion chemistry to modify the ball-like ring structure to accept metal ions binding. In their latest work, they successfully included ROD and Indium ions in the ring with nitrogen atoms.

The new dye of the band showed the strongest light absorption at the wavelength of 1600 nanometers under normal conditions, which is good in the second region close to IR. It has also been shown to be very photostable, which means that it will not break easily at light exposure. Detailed measurements of how the molecule reacts to magnetic fields and numerical calculations using the theory of functional density (DFT) showed how the unique distribution of electrons in the cloud covering the entire complicated structure of the metal binding molecule (also known as Pi -Rradicaid) It caused absorbance that is not possible in existing, similar compounds.

Because the second close IR is not so much absorbed by tissues, regions allergic to dye may be more exposed to light, enabling more pronounced imaging and better heat supply for therapy. The team hopes that their molecule will open the door to new approaches to deep tissue medicine, as well as more general applications of chemical catalysis.

These works were supported by the JSPS JP20H00406 and JP22K19937 subsidy numbers, JST Presto JPMJPR2103, Izumi Science and Technology Foundation, advanced research infrastructure for materials and nanotechnology in Japan (ARIM) (MEXT) NJRC Mater cooperation. . & Dev. And the scholarship of the Global Partner Tokyo from Tokyo Metropolitan University.