In July 2023, Dai Nippon Toryo (DNT) launched “Extracellular Vesicle Immunochromatographic Kit Exorapid-qIC^TM (CD9).” This is the world’s first immunochromatographic kit for research use targeting “extracellular vesicles (EVs),” particles secreted from cells.
An immunochromatographic kit refers to a test kit to determine positivity for certain targets by appearance of a colored test line in the region on which a test sample has been applied, as represented by diagnostic kits for influenza virus or coronavirus. Why did DNT, a company specialized in coatings, launch a product in the area of life sciences onto the market? This is closely linked to the company’s nanoparticle technology.

EVs, contained in blood and urine, are becoming more and more a focus of research, since they contain information on the original cells from which they have been secreted. For example, progress in research on EVs secreted from cancer cells is expected to allow early diagnosis of cancer.
“Extracellular Vesicle Immunochromatographic Kit Exorapid-qIC^TM (CD9),” which contributes to promotion of extracellular vesicle research, was born from a combination of DNT’s research on “anisotropic noble metal nanoparticles” and Shimadzu Corporation’s research on “life sciences.”
In general, coating utilizes a technology involving stable dispersion of particles in liquid.
“By applying our coating technology, we have pursued research on a technology to stably synthesize anisotropic (non-spherical shape) noble metal nanoparticles, such as disc-shaped gold nanoparticles (gold nanoplate) and silver nanoparticles (silver nanoplate), for approximately 20 years,” said Mr. Yoshikazu So and team leader Mr. Yuta Miyazawa, Functional Materials Development Group, Speciality Business Dept., DNT.

EVs
Immunochromatography test strip
Gold nanoplate-labeled antibodies
(a) When a sample solution containing EVs is applied on a test strip, EVs are captured by antibodies immobilized on the test strip.
(b) When gold nanoplate-labeled antibodies are applied, they bind to the EVs immobilized on the test strip in Step (a).
(c) When gold nanoplate-labeled antibodies accumulate in the part where EVs have been captured, a blue line is visually observed.

“We developed anisotropic particles originally as a coating material that cuts off infrared light emitted from displays. Then, in a search for other applications of this anisotropic particle technology, we found its potential in the life sciences market. In immunochromatography, metal nanoparticles have been widely used to have a test line develop a color. However, we noted that this method was disadvantageous in that due to few color variations, test results are difficult to see when several viruses are simultaneously tested. Then, with the belief that we, as a coating company, can help develop a multicolor test kit, we changed direction and strived to enter the life sciences area,” explained Mr. Miyazawa.

From 2015, DNT ran a booth at exhibitions to introduce the technology to diagnostic agent manufacturers. Each time, however, the response of such manufacturers was that they preferred utilizing mature, commercialized technology.

“When it comes to testing, reliability is important, and so, most of such manufacturers place an emphasis on adoption results of products or technologies. Hence, we were unable to find the first company that would adopt our technology. Then, we began to think that it might be earlier to create a test kit ourselves in around 2017. Just around that time, our brother company Shimadzu Corporation became interested in our technology, and a joint development project with them started,” Mr. Miyazawa explained.

Mr. Miyazawa was temporarily transferred to Shimadzu Corporation and worked at the Shimadzu Corporation research facility. There he himself was involved in the research on cancer diagnosis using EVs secreted from cancer cells.

“EV detection experiments are expensive and time-consuming. Some experiments need a device costing over 10 million yen or take as long as 3 to 5 hours to complete. We wondered what we should do to make research more rapid and conceived that if immunochromatography enables low-cost, rapid testing, there would be a high demand for the technology-based product. This expectation increased our motivation to develop such a product,” said Mr. Miyazawa.

The market of EV-based research reagents is growing at an annual rate of more than 30%. Given that DNT’s kit is the first-to-market, proposal-based product, there still remain uncertainties, although high demand is expected. Nevertheless, they chose to face the challenge of “putting it on the market even a day earlier.”

“We judged this product to be the most amenable to a prototyping strategy, in which a product is trial-marketed and then real customer feedback is incorporated in the improvement and development processes. While we were aiming at early launch of the product, we had to ensure satisfactory quality, needless to say. In a struggle to overcome this challenge, we conducted a lot of experiments, with several experiments run in parallel, allowing for any unexpected results from the experiments. Moreover, as we, a coating company, do not possess the full set of manufacturing equipment, we asked for help from other companies. Setting up the system for that is also our first experience,” said Mr. Miyazawa.

In the process of this development project, a patented technology of TOPPAN Inc. also became necessary. Thus, we proceeded with the research and development, blessed with cooperation and kindness of many people. The completed “Extracellular Vesicle Immunochromatographic Kit Exorapid-qIC^TM (CD9)” does not need dedicated devices, unlike conventional EV detection experiments, and this has reduced the initial cost. Furthermore, the kit has reduced the testing time to approximately 45 minutes and is also easy to handle, making it ideal for EV research start-up or simple evaluation.

In fiscal year 2023, DNT is widely promoting the product by disseminating information through presentations at academic meetings and webinars, with an eye toward achieving a large market share.
They ran a booth at the annual meeting of the Japanese Society for Extracellular Vesicles, held in October 2023, to disseminate information to researchers. They will continue with efforts to refine the extracellular vesicle immunochromatographic kit and at the same time to pursue the development of new technology using noble metal nanoparticles.

“Noble metal nanoparticles absorb a certain wavelength depending on the shape and thus allow large color variations. We are receiving inquiries from a lot of customers who would like to use the technology. We are also pouring efforts in sales of metal oxide nanoparticles, which are applied to anti-reflection film and the like. We showcased the metal oxide nanoparticles in ‘FILMTECH JAPAN,’ held in October 2023, and are receiving more and more inquiries about them as a coating material,” said Mr. Miyazawa.

Making things is challenging and laborious. However, Mr. Miyazawa and Mr. So say, “whether taking the first step or not determines our future, and success of our efforts requires the support and cooperation of the people involved. We hope we can work for a successful future together with people from various fields, not limited to those belonging to Mitsubishi Group, with a never-give-up spirit.”

With its catchphrase “DNT’s business is not limited to coatings!” in mind, DNT will dedicate its efforts to opening up new business in wide-ranging fields.