Pathogens invade their hosts by several mechanisms including binding to glycans (sugars) on our cell surface. This binding is a crucial stage in their infection cycle and understanding these processes and developing new diagnostics and treatments. In this work we used glycoyslated nanoparticles to investigate how carbohydrate-binding proteins on the surface of influenza (hemagglutinins) bind sialic acids. We used our gold nanoparticle platform to enable easy incorporation of the sialic acids at the ends of polymers immobilised onto the gold particles, ensuring they were colloidally stable but still capable of present the sialic acids. Using a range of assays we optimized their structure to maximise outputs. We then interrogated a panel of hemaglutinins from different influenza strains, including zoonotic (species-crossing) strains. Crucially, when influenza 'jumps species' (e.g. avian to human), the nature of the glycan it binds also changes, which we were able to rapidly map. These results showed that our nanoparticle platform is a suitable tool for interrogating viral surface proteins and for helping to understand zoonosis.

Read the paper here; Polymer-Stabilized Sialylated Nanoparticles: Synthesis, Optimization, and Differential Binding to Influenza Hemagglutinins