Groundbreaking research led by a Swansea University academic has revealed a synthetic glycosystem – a sugar-coated polymer nanoparticle – that can block Covid-19 from infecting human cells, reducing infection rates by nearly 99%.
The glycosystem is a specially designed particle that mimics natural sugars found on human cells. These sugars, known as polysialosides, are made of repeating units of sialic acid – structures that viruses often target to begin infection. By copying this structure, the synthetic molecule acts as a decoy, binding to the virus’s spike protein and preventing it from attaching to real cells.
Unlike vaccines, which trigger immune responses, this molecule acts as a physical shield, offering a novel approach to infection prevention.
Using advanced lab techniques to measure molecular interactions and simulate virus binding, researchers found that the glycosystem binds to the virus 500 times more strongly than a similar compound containing sulphates but no sugars. It was also effective at very low doses and worked against both the original SARS-CoV-2 strain and the more infectious D614G variant.
Tests on human lung cells showed a 98.6% reduction in infection when the molecule was present. Crucially, the research highlighted that its effectiveness stems not just from its charge, but from its precise sugar structure – giving this glycosystem its powerful infection-blocking capability.
The discovery is the result of collaboration between Swansea University, Freie Universität Berlin, and Charité – Universitätsmedizin Berlin.
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As the main corresponding author and research supervisor, Dr Sumati Bhatia, Senior Lecturer in Chemistry at Swansea University, said: “Leading this research, alongside our international partners, has been incredibly rewarding. It opens a new direction for using glycosystems as a therapeutic strategy against SARS-CoV-2 and could lay the foundation for a new class of antiviral therapies to protect those most at risk.”
The team is now preparing for further biological testing in high-containment laboratories to assess the molecule’s effectiveness against multiple virus strains.
T
his breakthrough could pave the way for antiviral nasal sprays, surface disinfectants, and treatments to protect vulnerable groups, offering a new line of defense against Covid-19 and future pandemics.
Source:
Journal reference:
Khatri, V., et al. (2025). Polysialosides Outperform Sulfated Analogs for Binding with SARS-CoV-2. Small. doi.org/10.1002/smll.202500719.
