To diagnose and treat malignant brain tumors at the same time

New therapy has been developed that allows for the detection of cancer cells within the body and the localized heating of surrounding water molecules for treatment. This technology is expected to be utilized in the future for diagnosing and treating malignant brain tumors.

A team made by Professor Lee Joon-seok of Hanyang University’s Department of Chemistry, Professor Lee Dong-yun at the Department of Bioengineering, and Professor Kim Young-pil at the Department of Life Science have developed multifunctional nano-particles capable of long-lifetime signal processing in the near-infrared region and photothermal therapy through localized heating of water molecules. The announcement was made by Hanyang University on June 19th.

The research team developed a lanthanide-based material made of neodymium-terbium (Nd-Yb) to heat water molecules in the 1.0 μm (micrometer: one-millionth meter) area, which is a near-infrared wavelength. The material generates a photothermal effect based on strong absorption in the 1.0 μm area of the water molecule, allowing only a part of the water to be heated.

The photothermal effect of neodymium ions, a material of conventional lanthanides, is based on Cross-relaxation (CR), and is not widely used because the photothermal effect is as low as 8.8%.

The research team devised particles that emit strong light in the 1.0 μm area by utilizing the phenomenon of water heating when using infrared lasers. Compared to the CR phenomenon-based photothermal effect of conventional neodymium ions, the light-emitting particles showed about three times improved efficiency.

The research team also added near-infrared imaging with a long-lifetime by doping the nanomaterial with thulium (Tm). When imaging a living thing, a fluorescent signal is generated by itself in the living body, making it difficult to identify a specific fluorescent signal to be observed. Nanoparticles developed by the research team have signals of several microseconds (1 millionth of a second) and can independently detect signals of nanoparticles alone by avoiding self-fluorescent signals of several nanoseconds (1 billionth of a second).

Professor Lee Joon-seok explained, "The existing 1.0 μm wavelength was limited in its application to the human body because it heats water molecules. We applied a new method of photothermal effects that selectively heats the water molecules around cancer cells, shifting our perspective. Based on this research, we will focus on the development of multifunctional nanoparticles for more efficient photothermal effects."

Professor Lee Dong-yun stated, "Through the commercialization of these research results, similar to AuroLase® made of approved silica material by the US FDA, it will be possible to utilize them in the treatment of intractable or recurrent cancer patients where surgical approaches are difficult."

This research, supported by the Ministry of Science and ICT and the National Research Foundation of Korea through the Basic Science Research Program (Mid-career Researcher, Basic Research Laboratory Support Project) and the Core Technology Development Program (Bio-Medical Technology Development Project, Advanced Convergence Technology Development Project), were published in the international academic journal “Nature Communications” on the 13th of last month.

[Photo 1] A joint research team at Hanyang University. (from left) Professor Lee Joon-seok, Professor Lee Dong-yun (Correponding author), PhD Kang Dong-kyu, and Dr. Kim Hyung-sik (the co-first author)

[Image 2] Schematic representation of multifunctional particles for long-lifetime near-infrared imaging and selective heating of water molecules surrounding malignant brain tumors.