Microgels are promising scaffolds for the presentation of biomolecules such as glycans. Coupling of the cell-surface glycan N-Acetyllactosamine (Galβ1,4GlcNAc, LacNAc) to cross-linked polyethylene glycol (PEG) provides a suitable procedure to study multivalent carbohydrate-protein interaction within microgels. By using drop-based microfluidics and radical polymerization, we produced biocompatible monodisperse microgels, which combine star-shaped PEG and allyl-activated LacNAc. The 20 µm microgels exhibit a wide mesh size and a highly accessible volume as shown by diffusion studies of fluorescent labelled thyroglobulin, a 660 kDa protein. Further, the accessibility of the glycans was investigated with glycan-binding proteins, named lectins. ECL, a galactose binding lectin, shows specific binding to LacNAc-functionalized microgels with a Kd in the micromolar range whereas with GS-II, a GlcNAc specific lectin, no interaction was observed. Concluding, we are able to produce glycan-functionalized microgels which are useful tools to scavenge lectins in biomedical applications.
Alexander Jans, Ruben R. Rosencrantz, Ana D. Mandić, Naveed Anwar, Sarah Boesveld, Christian Trautwein, Martin Moeller, Gernot Sellge, Lothar Elling, and Alexander J. C. Kuehne
Biomacromolecules 2017, 18 (5), 1460-1465, doi: 10.1021/acs.biomac.6b01754