The adhesive sheet could inactivate SARS-CoV-2 in minutes on contact. Illustrative image (Free Press Photo: CDC on Unsplash).

Handles, elevator buttons and even touch screens can stop being transmitters of the new coronavirus thanks to an adhesive plastic sheet developed in Brazil, which can inactivate SARS-CoV-2 in minutes by contact, according to a study released Tuesday.

The material, made from polyethylene and with silver and silica (silicon oxide) microparticles in its structure, proved to be capable of eliminating 99.84% of the new virus particles after two minutes of contact.

Launched by the Promaflex company, specialized in the production of this type of film, the material was developed by the Nanox company with the support of the innovative research program for small companies of the São Paulo State Research Support Foundation (FAPESP ).

Technical standards that measure antiviral activity in plastics and other non-porous surfaces establish that the material must confirm virucidal action in at least four hours.

Tests that followed the ISO 21702: 2019 standard, carried out in the biosafety level three (NB3) laboratory of the Institute of Biomedical Sciences of the University of Sao Paulo, showed that the material developed can eliminate the virus much faster.

« The plastic film with the additive proved to be capable of achieving this objective in a much shorter time and the virucidal action increased over time, » said Lucio Freitas Junior, a researcher at the Institute, cited in a note released by FAPESP.

For the study, material samples with and without silver and silica microparticles incorporated in the structure were used, which were kept in direct contact with SARS-CoV-2 at different time intervals.

After the stipulated periods had elapsed, the coronaviruses present in the material samples were collected and put in contact with Vero cells – a type of cell line used in microbiological cultures – to evaluate the capacity for infection and multiplication after exposure on the plastic film. .

The results indicated a reduction of almost 100% in the copies of SARS-CoV-2 that came into contact with samples of the adhesive sheet after two minutes of exposure to the material.

« As microparticles of silver and silica are added to the plastic mass during production, the antimicrobial action remains throughout the useful life of the material, » said Luiz Gustavo Pagotto Simões, director of Nanox.

However, the manufacturer of the plastic film with the additive recommends using it for up to three months to avoid material wear due to excessive contact.

The adhesive film is the second plastic material with silver and silica microparticles marketed by Nanox, which developed a reusable mask made with a flexible plastic and with the additive applied to its surface.
Silver and silica microparticles have also been applied by Nanox on fabrics for the development of anti-COVID-19 clothing.

In fabrics, the silver and silica microparticles are impregnated on the surface through an immersion process, followed by drying and fixing, called ‘pad-dry-cure’.