We demonstrate that cholesterol-modified polyethylene glycol has antiviral activity, exerted by anchoring to plasma membranes and sterically inhibiting viruses from entering cells. These polymers distribute sparsely on cell membranes even at binding saturation. However, the polymers have sufficient elastic repulsion energy to repel various kinds of viruses with sizes larger than the mean distances between anchored polymers, including SARS-CoV-2 pseudoparticles. Our strategy can be applied to protect the epithelium from viruses. When these polymers are applied to the epithelium, they localize on the apical surface due to the tight junction barriers, resulting in surface-only coating. Therefore, these polymers can prevent the entry of viruses into cells of the epithelium with minimal disturbance to lateral cell−cell interactions and organizations.
■ EXPERIMENTAL SECTIONSPlasmids, Viruses, and Cells. Plasmids pCAG-HIVgp and pCMV-VSV-G-RSV-Rev (obtained from Hiroyuki Miyoshi, Riken BRC, Japan) were used for packaging of lentiviruses. For SARS-CoV-2 pseudoparticles, the VSV-G gene in the pCMV-VSV-G-RSV-Rev was replaced with the spike gene (SARS-CoV-2, Wuhan-Hu-1, obtained from SinoBio, China). These plasmids were cotrasnfected to HEK293T cells with another plasmid, pLV-eGFP (obtained from Pantelis Tsoulfas) or pLenti CMV Puro LUC (obtained from Eric Campeau). Lentiviruses and SARS-CoV-2-PP are self-inactivating and not able to replicate. Both lentivirus and SARS-CoV-2 PP viruses were collected from a supernatant medium and concentrated using a Lenti-X concentrator kit (Takara bio, Japan). Lenti-X p24 Rapid Titer Kit (Takara Bio) was used to measure the titer of collected viruses by ELISA (enzyme-linked immunosorbent assay). Plasmids of AAV GFP, pAdDeltaF6, and pAAV2/2 (obtained from Fred Gage, James M. Wilson, and Melina Fan, respectively) were cotrasnfected to HEK293T cells to produce adeno-associated viruses, which were collected from both the medium and supernatant of cell lysis. The adeno-associated virus was not replicated in HEK293T cells in our infection assays due to the absence of genes from the adenovirus that