Lignin: A Sustainable Antiviral Coating Material

Abstract

Transmission of viruses through contact with contaminated surfaces is an important pathway for the spread of infections. Antiviral surface coatings are useful to minimize such risks. Current state-of-the-art approaches toward antiviral surface coatings either involve metal-based materials or complex synthetic polymers. These approaches, however, even if successful, will have to face great challenges when it comes to large-scale applications and their environmental sustainability. Here, an antiviral surface coating was prepared by spin-coating lignin, a natural biomass residue of the paper production industry. We show effective inactivation of herpes simplex virus type 2 (>99% after 30 min) on a surface coating that is low-cost and environmentally sustainable. The antiviral mechanism of the lignin surface was investigated and is attributed to reactive oxygen species generated upon oxidation of lignin phenols. This mechanism does not consume the surface coating (as opposed to the release of a specific antiviral agent) and does not require regeneration. The coating is stable in ambient conditions, as demonstrated in a 6 month aging study that did not reveal any decrease in antiviral activity. This research suggests that natural compounds may be used for the development of affordable and sustainable antiviral coatings.

Opportunities and Challenges for Lignin Valorization in Food Packaging, Antimicrobial, and Agricultural Applications

“…In a recent study, antiviral lignin surface coatings made of water insoluble lignins were prepared, which showed very efficient inactivation of HSV-2 (>99% after 30 min). Particular attention has been focused on the mechanism behind the antiviral activity of these coatings, which turned out to be strongly related to the lignin phenol content . The COVID-19 outbreak has highlighted the importance of antiviral surfaces.…”

“…Particular attention has been focused on the mechanism behind the antiviral activity of these coatings, which turned out to be strongly related to the lignin phenol content. 105 The COVID-19 outbreak has highlighted the importance of antiviral surfaces. Lignin is a promising material to develop affordable and sustainable antiviral coatings on a large scale, which deserves additional investigation.…”

Antiviral Peptides in Antimicrobial Surface Coatings—From Current Techniques to Potential Applications

“…Boarino et al showed that lignin is effective against Herpes Simplex Virus type 2 (HSV-2). Lignin can be used as a cost-effective and environmentally sustainable polymer-based antiviral and antimicrobial coating [ 68 ].…”

Antimicrobial and Flame-Retardant Coatings Prepared from Nano- and Microparticles of Unmodified and Nitrogen-Modified Polyphenols

“…Moreover, the coatings of such particles applied through other water-based methods typically show poor adhesion to the substrate and low cohesion, arising from the insufficient contact of the particles with the substrate and with each other. Moreover, the use of toxic organic solvents such as dioxane to facilitate the application of lignin coatings [ 13 , 23 ] is inconsistent with the current emphasis on green and safe industrial practices and products. By contrast, commercial tannins are water-soluble at room temperature, making them suitable only for coatings for which water resistance is not required, such as single-use hygienic garments or curtains.…”