Treating a viral disease is no simple feat. Drug resistance, latent reservoirs in the body, emerging novel viruses, and a frequent lack of specific treatments all complicate antiviral therapy. For decades, antiviral polymers have been studied for a range of infectious diseases. The field has emerged, expanded, and adapted over the past 70 years, producing unique classes of materials that hold promise for overcoming these obstacles. Antiviral polymers can directly inhibit viral replication and infection, usually by binding to the virus and preventing it from invading a host cell. They can also serve as microbicides or antiviral drug-delivery vehicles. This Perspective outlines the significant advances and challenges in the field. We discuss polymers with activity against viruses with limited treatment options (hepatitis C), ubiquitous presence (influenza, norovirus), or long-term complications (HIV). We also explore insights into different mechanisms of action, and we offer ideas on how the field of antiviral polymers might advance in the future.

Photochemical Nitric oxide releasing composite materials (Photo-NORMs) were prepared using biocompatible polymers and the photochemical nitric oxide donor complex (CrONO). We have demonstrated nitric oxide (NO) release from the solid composites for extended (>30 hours) and controlled (20-100 pmoles s(-1)) durations after visible light irradiation. Quantitation of the efficiency of NO release from the composites shows that polymer gas permeability most dramatically affects the overall efficiency (QY) of photochemical NO release, where polymers with higher gas permeability have a higher QY of nitric oxide release. Composites were also prepared with β-phase lanthanide-doped NaYF4 upconverting nanoparticles (UCNPs). Controlled Nitric oxide release was achieved via near infrared (NIR) irradiation. A prototype LED device shows proof-of-concept that such photoresponsive NO-releasing composites could be applied to implantable systems, where the amount of NO released is modulated by changing irradiation time and light intensity. This research provides the guidelines necessary to move towards device fabrication and testing in actual tissue to evaluate the photo-NORMS as a reliable option for nitric oxide release in vivo.