Virus removal from aqueous environments with polyelectrolyte coatings on a polypropylene fleece

The adsorption of viruses from aqueous solution is frequently performed to detect viruses. Charged filtration materials capture viruses via electrostatic interactions, but lack the specificity of biological virus‐binding substances like heparin. Herein, we present three methods to immobilize heparin‐mimicking, virus‐binding polymers to a filter material. Two mussel‐inspired approaches are used, based on dopamine or mussel‐inspired dendritic polyglycerol, and post‐functionalized with a block‐copolymer consisting of linear polyglycerol sulfate and amino groups as anchor (lPGS‐b‐NH2). As third method, a polymer coating based on lPGS with benzophenone anchor groups is tested (lPGS‐b‐BPh). All three methods yield dense and stable coatings. A positively charged dye serves as a tool to quantitatively analyze the sulfate content on coated fleece. Especially lPGS‐b‐BPh is shown to be a dense polymer brush coating with about 0.1 polymer chains per nm2. Proteins adsorb to the lPGS coated materials depending on their charge, as shown for lysozyme and human serum albumin. Finally, herpes simplex virus type 1 (HSV‐1) and severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2) can be removed from solution upon incubation with coated fleece materials by about 90% and 45%, respectively. In summary, the presented techniques may be a useful tool to collect viruses from aqueous environments.

Adaptive Flexible Sialylated Nanogels as Highly Potent Influenza A Virus Inhibitors.

Flexible multivalent 3D nanosystems that can deform and adapt onto the virus surface via specific ligand-receptor multivalent interactions can efficiently block virus adhesion onto the cell. We here report on the synthesis of a 250 nm sized flexible sialylated nanogel that adapts onto the influenza A virus (IAV) surface via multivalent binding of its sialic acid (SA) residues with hemagglutinin spike proteins on the virus surface. We could demonstrate that the high flexibility of sialylated nanogel improves IAV inhibition by 400 times as compared to a rigid sialylated nanogel in the hemagglutination inhibition assay. The flexible sialylated nanogel efficiently inhibits the influenza A/X31 (H3N2) infection with IC50 values in low picomolar concentrations and also blocks the virus entry into MDCK-II cells.