The spread of disease is a huge global problem in modern society. Micro-organisms such as bacteria, fungi and viruses represent significant threats to our modern, hygienic lifestyle, which has been highlighted recently with the COVID-19 pandemic. Infection is a major medical complication associated with healthcare environments, resulting in an increased demand for antimicrobial and anti-viral coatings and surfaces.
The global situation with COVID-19 has caused an increased demand for antimicrobial and antiviral treatments that can keep surfaces clean, particularly in health care settings. Although surfaces have been developed that can combat bacteria, there is a need for surfaces that can also kill viruses via the use of durable antiviral and antibacterial coatings.
Advanced Bactericidal & Viricidal Coatings have numerous applications, for virtually all surfaces including:
- fabric (mask, gloves, doctor coats, curtains, bed sheet)
- metal (lifts, doors handle, nobs, railings, public transport)
- wood (furniture, floors and partition panels)
- concrete (hospitals, clinics and isolation wards)
- plastics (switches, kitchen and home appliances).
Hospital-acquired infections (HAIs)
As evidenced with the COVID-19 outbreak, healthcare-associated infections (HCAI), also termed nosocomial infections, are complications of healthcare that result in elevated patient morbidity and mortality. HCAI increase healthcare costs for patients, hospitals and insurers due to extended hospitalization and associated care.
Incidence of HCAI, however, are generally considered preventable. Complementing routine hand hygiene practices, cleaning and disinfection, the use of novel Bactericidal & Viricidal coatings hold promise based on the application of materials and chemicals with persistent bactericidal or-static properties onto surfaces or in textiles used in healthcare environments.
Microbes accumulating on various surfaces spread through contact from one place and person to another, transmitting infectious diseases. Colds, influenzas, Norovirus, and the majority of causes of hospital infections, such as MRSA, ESBL, and VRE, are transmitted via contact. The use of Advanced Bactericidal & Viricidal Coatings and Surfaces is important to curb the spread of infection in facilities with high hygiene standards, such as hospitals, labs, clinics and homes for the elderly. Their deployment allows for the successful delay and/or prevention of recontamination following conventional cleaning and disinfection by problematic microbes such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), among others.
Reusable Personal Protective Equipment (PPE)
It is critical to ensure medical, paramedical and other personnel are safe from contracting coronavirus. N95 respirators filter out 95% of incoming particles, including viruses and bacteria to protect from potential infection. Medical medical workers are reporting dire shortages of these and other personal protective equipment (PPE) as they are not reusable.
The use of Antiviral Nanocoatings can used to allow for reusable anti-COVID-19 Triple Layer Medical masks and N-95 respirators. Self-cleaning hydrophobic nanocoatings are also candidates for use in face masks. It is widely believed that spread is transmitted through moisture. The use of water-repellent coatings greatly decreases the adhesion of the virus to surfaces.
Facemask coatings
Novel Bactericidal & Viricidal coatings have been developed for facemasks to reducing the risk of COVID-19 transmission. Antimicrobial nanoparticle (nanosilver, graphene, nanoparticle titanium dioxide) based coatings and hydrophobic coatings have been commercialized by several companies.
Wipe on coatings
Third generation wipe-on glass nanocoatings can allow for hard surfaces with a self-disinfecting performance for a period of several months, to several years. Application can be made at the consumer level. The technology has been developed by Nano-Care AG. The virus can survives for two to three days on surfaces like plastic and stainless steel which is a concern for health care workers in facilities that largely feature these materials. Surfaces that can be hand coated with antiviral nanoparticles can significantly address this problem for extended periods.
Long-term mitigation of surface contamination with nanocoatings
While disinfecting high-contact surfaces is an important practice to prevent the spread of pathogens, these surfaces can be easily re-contaminated after the use of conventional surface disinfectants. The use of Advanced Bactericidal & Viricidal coatings allows for permanent mitigation of microorganisms and viruses. These can be applied at manufacturing or retrofitted.
Metallic-based coatings
Many successful metallic-based coatings have been developed using silver, titanium, zinc, and copper nanoparticles. Most of these applications involve leaching metallic ions in order to disrupt the membrane of bacteria and prevent the proliferation of bacteria on the surface of the device. Metal-, metal alloy or metal nanoparticle-based surfaces have been used extensively as antimicrobial surfaces in water treatment (filters, water pipes), in ventilation and air-conditioning systems, general high touch surfaces such as door handles and knobs, and more importantly in healthcare settings. Antibacterial nanoparticles comprise metals (e.g. silver) and metal oxides (e.g. zinc oxide and copper oxide), naturally-occurring antibacterial substances (e.g. enzymes), carbon-based materials, and surfactant-based nanoemulsions.
It is believed that high surface area to volume ratios and novel chemico-physical features of different nanomaterials are associated with efficient antimicrobial activities. Known antimicrobial mechanisms of nanomaterials include: (i) photocatalytic generation of reactive oxygen species (ROS) that lead to damage of bacterial and viral components, (ii) compromising of the bacterial cell wall or membrane, and (iii) interruption of energy transduction within bacterial membranes. Zinc oxide (ZnO), iron oxide (Fe3O4), copper oxide (CuO), magnesium oxide (MgO), and titanium dioxide (TiO2) nanoparticles have been shown to possess potent antimicrobial activity over a range of Gram-positive and Gram-negative bacteria, including resistant bacterial strains. Their antibacterial activity is usually related to the generation of ROS, attributed to their intrinsic photocatalytic activity or to the release of the metallic ions.
Polymer-based coatings
Many polymer-based coatings have been developed using different quaternary ammonium salts and cationic polymers. These coatings primarily function through either a disruption of the bacterial membrane using cationic charges or hydrophobic interactions repelling the adherence of bacteria. The benefit of these coatings is that they are primarily non-leaching coatings and therefore demonstrate long-term intrinsic antibacterial activity, are biocompatible, and do not cause any significant cytotoxicity.
A variety of polymer-based intrinsic antibacterial coatings have been developed that either function to repel the attachment (via hydrophobicity or nanotopographies) or directly kill bacteria that come in contact with the surface of the biomaterial (via cationic interactions)
Polymer-based coatings are particularly advantageous because they do not leach any compounds into the body (i.e. metal ions or drugs) and are therefore typically very biocompatible and demonstrate long-lasting antibacterial activity while minimizing the risk of the development of drug-resistant strains of bacteria. Additionally, the coatings can be tailored for broad-spectrum antibacterial activity and are typically very robust. While these coatings offer many advantages over alternative coatings, some varieties do not kill the bacteria surrounding the implant but simply repel it. In some applications, this is sufficient; however, often it is necessary to completely eradicate the bacteria to prevent its proliferation instead of repelling it.
Companies
Allied BioScience, Inc
www.alliedbioscience.com
SurfaceWise™EPA-registered microbiostatic surface coating (EPA Reg. Number: 92082-1) that provides an barrier to inhibit the growth of bacteria, fungi (mold and mildew) and algae which cause odor, staining and discoloration.
Covalon Technologies Ltd.
www.covalon.com
CovaGuard™ is an antimicrobial technology formulated to kill the COVID-19 virus (or “SARS-CoV-2”) and other viruses, bacteria, and pathogens. CovaGuard™, has been specifically formulated to be effective at killing pathogens like the COVID-19 virus on contact with the added benefit of providing persistent protection by trapping and deactivating microbes over an extended period of time. Based on testing to date, the CovaGuard technology has demonstrated sustained activity of up to four days. The CovaGuard technology is designed to be safely applied on skin as well as protective medical equipment like masks and gloves, whether used for the first time or reused.
Envision SQ
https://envisionsq.com/
EnvisionSQ is a joint effort with University of Guelph to develop an innovative self-sterilization clear coating product (EnvisionSQ Clear Coating – NanoCleanSQ) that can be easily applied to hard surfaces to help prevent spread of the Coronavirus. NanoCleanSQ kills bacteria and viruses on contact, particularly coronaviruses, and is safe and durable, providing long-lasting antibacterial and antiviral protection. Since March 2020, the company has scaled up production to more than 1,000 litres per week.
GrapheneCA
https://grapheneca.com/
The company is developing a graphene-based coating with anti-bacterial and anti-viral properties. GrapheneCA’s coating is being formulated to be applied in the form of paints and varnishes to walls and surfaces of public settings that are high risk areas for micro-organisms such as bacteria and viruses, including shopping malls, metro stations, airports and event halls. The Company’s formula has been shown in laboratory tests to blocks the metabolism of micro-organisms by restricting cellular respiration and cell division. Furthermore, assessments shown that micro-organisms die when coming into contact with surfaces covered with the coating’s components.
Inhibit Coatings Limited
www.inhibitcoatings.com
Inhibit Coatings uses a unique silver particle functionalisation method that produces a low leaching, long lifetime, antimicrobial coating. Tests to date show extremely low leaching rates of < 1 ppb/cm2/day. The technology produces silver particles evenly dispersed throughout the polymer coating. Only very small amounts of silver are required – typically less than 0.1%.
The technology has been applied to a number of resin systems including acrylics, epoxies and polyurethanes. These coatings have been effective at reducing E. coli, S. aureus, L. monocytogenes by over 99.997% and have been shown to retain antimicrobial activity after numerous cleanings with common cleaning agents, making them ideal for food safety, medical and HVAC, amongst other applications.
Integricote
http://integricote.com
Self Cleaning Hydrophobic Nanocoatings (SCHN) range of nanocoatings are completely transparent and very robust, having covalently linked, bonded structures. PFOS free (Perfluorooctanesulfonic acid) and PFOA free (C8 or Perfluorooctanoic acid) that can be used to keep surfaces clean, stain resistant and dry. The company claims that its coatings can be used to mitigate the spread of coronavirus and can manufacture approximately 400 gallons of coating, which can cover about 12,000 masks per day. The company is also developing a non-toxic, environmentally-friendly solution that can be applied to the surface of everyday objects that will kill the virus on contact.
Further information
The Global Market for Advanced Bactericidal & Viricidal Coatings and Surfaces
Published September 2020, available at https://www.futuremarketsinc.com/the-global-market-for-advanced-bactericidal-viricidal-coatings-and-surfaces/
