A domestic research team has developed a technology that can complete sterility testing of pharmaceuticals in just one day. Previously it took two weeks (14 days) to check the results, but this technology needs only one day.
A research team led by Kwon Seong-hoon, a professor in the Department of Electrical and Computer Engineering at Seoul National University, together with Professor Lee Eun-joo at Seoul National University Hospital and a team led by Professor Kim Tae-hyun at Korea University, announced on the 14th that they had developed the "rapid sterility test method (NEST, Nanoparticle-based Enrichment and rapid Sterility Test)." The results were recently published in the international journal Nature Biomedical Engineering.
Sterility testing is an essential procedure to confirm that pharmaceuticals or medical devices are free of bacterial contamination. However, the conventional method required observing bacterial growth, so it took at least 14 days to obtain results.
As a result, cutting-edge biopharmaceuticals with short shelf lives, such as cell and gene therapies, often lost efficacy while waiting for test results, or patients missed the optimal treatment window. In some cases, therapies had to be administered to patients before sterility results became available.
The research team drew inspiration from the immune response by which our bodies distinguish invading microbes. They created magnetic nanoparticles coated with special peptides that bind only to bacteria, enabling rapid concentration of trace amounts of bacteria in pharmaceuticals.
The bacteria collected in this way can be checked immediately with a newly developed sensor (imaging chip). The chip detects the minute signals emitted by viable bacteria as light (fluorescence) and determines the presence of bacteria in as little as 5 hours and up to 18 hours. It is precise enough to capture even a single bacterium in 1 milliliter (ml).
The team conducted validation experiments using real patient samples, including high-cost stem cell therapies and CAR-T cell therapies. As a result, they confirmed that the technology works reliably not only in the laboratory but also in actual therapeutic samples.
Lee said, "Until now, treatment often had to proceed before sterility verification was completed, but going forward we will be able to confirm sterility on the day of testing and then administer the therapy safely to patients," adding, "Patient safety will improve significantly, and this could also bring changes to the regulatory framework."
The research team predicted that this technology could expand beyond pharmaceutical testing into a range of fields, including sepsis diagnosis, food safety, cosmetics verification, and early responses to infectious diseases.
Kwon said, "We will continue clinical validation so that NEST can become a new standard that ensures patient safety," and "We plan to contribute to improvements in global medical regulations beyond Korea."
References
Nature Biomedical Engineering (2025), DOI: https://doi.org/10.1038/s41551-025-01524-3