In a world first, Sharp Corporation developed a device equipped with Plasmacluster technology, which exposed an airborne novel coronavirus (SARS-CoV-2) to Plasmacluster ions for approximately 30 seconds*3, and demonstrated that the virus infectious titer*4 was reduced more than 90%. This achievement was accomplished in collaboration with Professor Jiro Yasuda of the National Research Center for the Control and Prevention of Infectious Diseases/Institute of Tropical Medicine, Nagasaki University, Professor Asuka Nanbo (a Board member of the Japanese Society for Virology) of the same institution, and Professor Hironori Yoshiyama of the Department of Microbiology, Shimane University Faculty of Medicine (also a Board member of the Japanese Society for Virology), and in cooperation with Nagasaki University, an internationally respected authority on infectious disease research.
1. In December 2019, an outbreak of “Coronavirus disease 2019 (COVID-19)” caused by a novel coronavirus (SARS-CoV-2) was reported, and by August 2020, more than 25 million people have been infected with SARS-CoV-2 and more than 840,000 individuals died of this infectious disease in a world*5. This outbreak represents an urgent problem facing society, and demands that immediate countermeasures be taken across a wide range of fields. 2. In 2004, Sharp demonstrated the effectiveness of Plasmacluster technology against feline (cat) coronavirus, a member of the Coronaviridae family*6. In the following year, 2005, Sharp also demonstrated its effectiveness against the original SARS coronavirus*7 (SARS-CoV), which caused the outbreak (2002-2003) and genetically similar to the novel coronavirus (SARS-CoV-2). Now, Sharp has demonstrated its effectiveness against SARS-CoV-2 in airbornedroplets.
3. Since 2000, Sharp has promoted academic marketing*8 to demonstrate the effectiveness of Plasmacluster technology, working in collaboratio with independent third-party research organizations around the world. Thus far, numerous independent research organizations have proven its clinical efficacy in suppressing the activity of harmful substances including new pandemic influenza viruses, drug-resistant bacteria, and mite allergens, as well as in reducing bronchial inflammation levels*9 in children with asthma. At the same time, the safety of Plasmacluster ions has also been confirmed*10. Sharp will continue to contribute to society by conducting a wide range of studies demonstrating the effectiveness of Plasmacluster technology.
Comments from Dr. Jiro Yasuda, Professor, National Research Center for the Control and Prevention of Infectious Diseases, Nagasaki University Disinfectants such as alcohol and detergents (surfactants) are well-known to be effective to reduce the risk of the virus on materials, however, for infection via aerosols (microdroplets), there are few effective countermeasures such as a mask.
Here, effective inactivation of SARS-CoV-2 in airborne droplets by Plasmacluster technology was demonstrated.- It would be expected that it is useful to reduce the risk of infection in real spaces including office, home, medical facilities and vehicles.
Overview of Verification Test
Testing organization: National Research Center for the Control and Prevention of Infectious Diseases (CCPID)/Institute of Tropical Medicine, Nagasaki University
Verification test apparatus: Virus testing device equipped with Plasmacluster technology
Plasmacluster ion concentration: Approx. 10 million/cm3 (in the vicinity of the Plasmacluster ion generator)Test space volume: Approx. 3 liters Control study: Comparison using the device described above without Plasmacluster ion generation Validation virus: Novel Coronavirus (SARS-CoV-2)Test method 1) Pass the aerosolized virus through the test devise from the generator. 2) Recover the aerosolized virus after exposure to Plasmacluster ions. 3) Calculate the infectious virus titer of the recovered virus solution by a plaque assay*. * A standard assay to evaluate the number of infectious virus in the sample.
Verification Test Results
Table 1.
Effect of Plasmacluster ions on infectious titer of novel coronavirus (SARS-CoV-2) suspended in air,
Figure 2. Effect of exposure to Plasmacluster Ions on infectious titer of Novel Coronavirus (SARS-CoV-2) Figure 3. Representative result of plaques assay
About Plasmacluster Technology
Positively charged ions (H+ (H2O)m) and negatively charged ions (O2– (H2O)n) are released into the air simultaneously, and the positive and negative ions instantaneously bond on the surface of airborne bacteria, fungi, viruses, allergens, and the like,
becoming OH (hydroxyl) radicals which have very high oxidizing power. This is a unique air purification technology that works to suppress the activity of bacteria, etc., by breaking down proteins on their surface by a chemical reaction.
How Plasmacluster Ions are generated
Positive and negative voltages are applied to discharge electrodes to electrically split airborne water and oxygen molecules into hydrogen and oxygen. This creates positively charged hydrogen ions (H+) and negatively charged oxygen ions (O).
The airborne water molecules around ions like bunches of grapes, making each ion stable cluster ion.
Mechanism for Inhibiting the Activity of Airborne Bacteria
Plasmacluster Ions inhibit activity by cleaving proteins on the cell surface, thereby damaging the cell membrane
Comparison of Oxidizing Power
The OH– (hydroxyl) radical has the strongest oxidizing power among active oxygen species
*1 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): The strain of coronavirus that causes coronavirus disease 2019 (COVID-19).
*2 In ion-emission air purification technologies (as of September 7, 2020; based on Sharp research).
*3 Calculated by dividing the test space volume by the flow recovery rate, assuming that the aerosol containing the virus is passing through the space at a constant speed.
*4 Number of infectious virus
*5 Based on data from Johns Hopkins University (as of August 31, 2020).
*6 Announced on July 27, 2004.
*7 Severe acute respiratory syndrome-related coronavirus: The species and its viruses – a statement of the Coronavirus Study Group. bioRxiv doi 10.1101/2020.02.07.937862 (February 11, 2020).
*8 A marketing method to promote commercialization of products based on verification of scientific data on the effectiveness of a technology in collaboration with leading-edge academic research institutions.
*9 Announced on September 18, 2014.
*10 Tests conducted by LSI Medience Corporation (inhalation toxicity, eye/skin irritation/corrosion, and teratogenicity tests, plus a two-generation reproduction toxicity study)