A “Virus Angel” should Enable Quick Diagnoses
Our immune system can fight many diseases of the respiratory system itself, and medical treatment is often not necessary. However, if the symptoms worsen, shortness of breath and an increase in temperature, then immediate medical assistance is required. To ensure optimal treatment, one question is essential: “What pathogen are we dealing with?” Because many respiratory viruses lead to similar symptoms but sometimes require very different treatments.
Cambridge researchers are showcasing their newly developed methodology in the journal Nature Nanotechnology – as a way to test patient samples for multiple viruses and virus variants simultaneously over a short period of time.
In the future, clinicians should be able to quickly and cost-effectively distinguish between different viral pathogens, rule out bacterial infections, and thereby reduce unnecessary antibiotic intake.
DNA traps are designed to Capture Viruses
Until now, the standard methodology for detecting pathogens has been the polymerase chain reaction (PCR) technique, which became well known through corona tests. However, the pathogen’s genetic material must first be replicated and only one virus can be detected at a time.
Although PCR tests can provide accurate results, they are expensive and time-consuming. This can be a convenient drawback: early diagnosis often improves a patient’s prognosis.
A multidisciplinary team of physicists, engineers, chemists and clinicians led by Philip Boskovitch of the University of Cambridge tackled this problem: they developed a method called nanobait that uses DNA bait, so to speak, to fish for viral genomes in patient samples.
With it, you should be able to get results in just a few minutes instead of hours or days. A nanograft is a strand of DNA that has a shorter single-stranded DNA sticking out of its sides, which is the graft. These contain sequences complementary to the corresponding viral RNA, so that parts of the viral genome can specifically “take” their bait.
Naonobait contains up to five different decoys, making it possible to distinguish between different respiratory viruses such as influenza virus, RSV virus, rhinovirus, SARS-Cov2 virus and its variants at once.
The Micropore Provides information about the Structure
However, based on association alone, it is not possible to tell which pathogen you are dealing with. You should read the “Fishing” culture first. Bošković’s team uses what’s called nanopores for this. This method is already in use for large-scale next-generation sequencing – it’s very fast and accurate.
The evaluation principle using nanopores is based on the conversion of molecular structures into electrical or digital information. The test particle, a nanobait, is sent through a small opening through which an electrical potential is applied.
When a molecule moves, it affects the electric flow according to its structure. These changes can finally be measured.
In this way, the individual bases of the DNA strand are marked in the next generation sequence. But it is not necessary to go so far in the case of a nanograft, here it is enough to differentiate whether the viral RNA is linked to different baits or not.
No more is needed, so when nanobaits are used there are only a few minutes between taking a patient sample and potential pathogen detection. To achieve this in everyday life, Bošković would like to integrate technology into mobile devices and thus make them more accessible.
“I am sure that, with the right partners, we can expand the method of use in the health area in a few years”, says the doctoral student, who received a Cambridge Applied Research Society award for his development in 2022.
