A research group led by Professor Toru Wakihara of Graduate School of Engineering at the University of Tokyo and Nippon Paint Holdings Co., Ltd. has found that proton-form zeolites have an excellent inactivation effect against the influenza virus and the COVID-19 virus.
The finding shows that proton-form zeolites have good prospects as a novel anti-viral material that is inexpensive, resistant to discoloration and suitable for many applications. This research conducted as part of the joint research program based on the Industry-Academia Co-creation Agreement between The University of Tokyo and NPHD concluded on May 18, 2020.
Zeolites Resisting to Viruses & Discoloration
Alcoholic disinfection of surfaces and fingers is recommended to prevent viral transmission via contact with surfaces. However, alcohol disinfection is not effective for a long time, and consequently is not able to control the spread of infections sufficiently.
To solve this problem, the research group is conducting experiments with the goal of developing materials and coatings that have anti-viral efficacy on many types of surfaces. Zeolites, which are crystalline porous materials, especially silver ion (Ag⁺)-exchanged zeolites, are known to have anti-bacterial properties. In fact, there are many practical applications for Ag⁺-exchanged zeolites.
While there are many studies on the anti-bacterial properties of zeolites, there are still only a few studies on the anti-viral properties of these materials. Ag⁺-exchanged anti-bacterial zeolite materials have disadvantages involving high cost caused using Ag⁺ and the discoloration of materials. Therefore, we conducted research on zeolites that are both resistant to viruses and discoloration.
The research group evaluated the anti-viral properties of proton-form zeolites through an anti-viral activation test using an influenza virus. We also observed the virus after contact with the material by using transmission electron microscopy and examined the mechanism of virus destruction.
The results showed that the virus infection titer was reduced to below the detection limit when influenza viruses were in contact with proton-form zeolites compared to when the virus inactivation test was conducted using zeolites without metal cation ion-exchange.
Total Destruction by Partially Damaging Viral Envelope
In addition, it was observed that viruses which contacted zeolites without metal cation ion-exchange retained their spherical shape, whereas viruses which contacted the proton-form zeolites were destroyed.
The results of the study indicated that the anti-viral effect of proton-form zeolites comes from the partial damage of the viral envelope when zeolites contact the virus, which leads to the of the virus.
The study has found that proton-form zeolites are a promising novel material with powerful anti-viral properties even without metal cation ion-exchange, such as with Ag⁺. Thus, proton-form zeolites can be used in many applications as an anti-viral material featuring low cost and discoloration resistance through research on anti-viral materials and coatings.
Source: Nippon Paint Holdings