Periodic Reporting for period 1 - Triple-A-COAT (Sustainable Development of a Safe and Biobased Antimicrobial, Antifungal and Antiviral Nanocoating Platform)
Berichtszeitraum: 2022-09-01 bis 2024-02-29
Following COVID-19, the world needs to be better prepared for future pandemics, as well as ongoing threats from infectious diseases such as seasonal influenza, hospital superbugs and stomach infections. Many disease-causing microorganisms, including bacteria, viruses and microscopic fungi, are spread through frequently touched surfaces, such as door handles, seat covers and rails. There is an increasing interest in antimicrobial coatings for such surfaces especially in busy areas such as public buildings and on public transport. These can inhibit microbial contamination or growth on surfaces, especially in between cleaning.
Current antimicrobial coatings use biocide chemicals such as silver-based agents to kill microorganisms. However, these can damage the environment, and microorganisms can develop resistance so the chemicals become less effective over time. Also, some microorganisms form a biofilm which protects them and helps them survive longer. We need new antimicrobial strategies that avoid resistance development as well as being effective against multiple kinds of microorganisms, including those that form biofilms.
It is also important that new antimicrobial coatings are safe and sustainable through all stages of production, application and use. New nanomaterials are being investigated in particular as the basis for new antimicrobial coatings. Their safety must be thoroughly tested at every stage of development.
The EU-funded Triple-A-COAT project is developing a new antimicrobial, antifungal and antiviral coatings for frequently touched surfaces, designed for use in buses. The project is using nanocellulose as the basis of its coatings technology. This is a material obtained from forestry wastes, or can be made by special bacteria in the lab. It has many potential applications, typically as a replacement for plastic, such as in in food packaging. In Triple-A-COAT we are using nanocellulose in place of oil-based materials as a more sustainable option.
Triple-A-COAT is using antibiofilm compounds, antimicrobial peptides, and nanopatterning inspired by antimicrobial surfaces found in nature, such as on dragonfly wings. These new approaches should give us antimicrobial coatings which effectively inhibit micro-organisms while preventing the development of antimicrobial resistance.
The most promising coatings developed in the project will be tested in a lifelike simulation of a bus. We will also conduct a thorough life cycle assessment of the new coatings to measure their environmental performance in comparison with existing coatings. The results of the project will then be developed commercially, with new coatings available for use in public transport, hospitals and other busy places within a few years after the end of the project.
Current antimicrobial coatings use biocide chemicals such as silver-based agents to kill microorganisms. However, these can damage the environment, and microorganisms can develop resistance so the chemicals become less effective over time. Also, some microorganisms form a biofilm which protects them and helps them survive longer. We need new antimicrobial strategies that avoid resistance development as well as being effective against multiple kinds of microorganisms, including those that form biofilms.
It is also important that new antimicrobial coatings are safe and sustainable through all stages of production, application and use. New nanomaterials are being investigated in particular as the basis for new antimicrobial coatings. Their safety must be thoroughly tested at every stage of development.
The EU-funded Triple-A-COAT project is developing a new antimicrobial, antifungal and antiviral coatings for frequently touched surfaces, designed for use in buses. The project is using nanocellulose as the basis of its coatings technology. This is a material obtained from forestry wastes, or can be made by special bacteria in the lab. It has many potential applications, typically as a replacement for plastic, such as in in food packaging. In Triple-A-COAT we are using nanocellulose in place of oil-based materials as a more sustainable option.
Triple-A-COAT is using antibiofilm compounds, antimicrobial peptides, and nanopatterning inspired by antimicrobial surfaces found in nature, such as on dragonfly wings. These new approaches should give us antimicrobial coatings which effectively inhibit micro-organisms while preventing the development of antimicrobial resistance.
The most promising coatings developed in the project will be tested in a lifelike simulation of a bus. We will also conduct a thorough life cycle assessment of the new coatings to measure their environmental performance in comparison with existing coatings. The results of the project will then be developed commercially, with new coatings available for use in public transport, hospitals and other busy places within a few years after the end of the project.
Three different kinds of nanocellulose are used in Triple-A-COAT: carbon nanocrystals (CNC), cellulose nanofibres (CNF), and bacterial cellulose (BC). They have differing nanostructures and physical properties, and in Triple-A-COAT each nanocellulose material is provided by an industry partner. The unmodified materials were exchanged at the start of the project, and analysed to understand fully their physical and chemical characteristics. This unmodified material was also used to select and optimise the tests for antimicrobial and antibiofilm activity. We have found no significant antimicrobial, antiviral or antibiofilm activity in any of the three types of unmodified nanocellulose. So further modification is required to obtain an antimicrobial, antiviral or antifungal material. Also the unmodified nanocellulose has passed the first toxicity tests (in cells). More complex tests to be performed in the next period, including for inhalation toxicity.
Nanocellulose can be chemically modified quite easily, to graft active compounds to the structure and make an antimicrobial material. A two-step chemical synthesis for grafting the antibiofilm compound (amino-2-aminoimidazole) has been developed. The resulting modified nanocellulose is currently being analysed and tested.
Our compounds may also be attached to nanocellulose through their natural, physical adhesion. We already know that the antimicrobial peptides have a strong affinity for cellulose. It is actually difficult to remove them once they are bound. This may be an effective way to create an antimicrobial nanocellulose material, but we are still in the process of verifying the long term stability of the formulation, and that antimicrobial activity is retained after adsorption of the compound. This approach may also work for the antibiofilm compound, and we are currently investigating this possibility alongside chemical modification.
Work on nanopatterning of nanocellulose has commenced. The innovative method which has already been published, uses physical wave patterns to cause a spontaneous buckling or wrinkling of the surface. The creation of patterns on nanocellulose has been demonstrated , and many different patterns are now being tested to see which have the best antimicrobial or antibiofilm activity.
Also, Triple-A-COAT partners have been developing ways to make effective coatings, firstly using the unmodified nanocellulose. Nanocellulose can be sprayed onto surfaces using standard equipment, as used for paint spraying. The three types of nanocellulose used in Triple-A-COAT have different physical properties and partners have worked on formulations that give optimal performance for spray coating. Another key requirement is that the coatings adhere well to various surface materials, including glass, metal, plastic and textiles. Nanocellulose itself can stick very well to certain types of material, but for others, extra ingredients may be useful as a linker to obtain a durable coating. Also, cross linking compounds are being used to adjust the coating properties. We are evaluating many different formulations using standard industry methods for coating durability relevant for frequently touched surfaces.
Over the next few months we shall select the best performing formulations for further development and optimisation. This stage of the work will include scaling up of production so that sufficient material is available for the final demonstration in the bus simulation.
Nanocellulose can be chemically modified quite easily, to graft active compounds to the structure and make an antimicrobial material. A two-step chemical synthesis for grafting the antibiofilm compound (amino-2-aminoimidazole) has been developed. The resulting modified nanocellulose is currently being analysed and tested.
Our compounds may also be attached to nanocellulose through their natural, physical adhesion. We already know that the antimicrobial peptides have a strong affinity for cellulose. It is actually difficult to remove them once they are bound. This may be an effective way to create an antimicrobial nanocellulose material, but we are still in the process of verifying the long term stability of the formulation, and that antimicrobial activity is retained after adsorption of the compound. This approach may also work for the antibiofilm compound, and we are currently investigating this possibility alongside chemical modification.
Work on nanopatterning of nanocellulose has commenced. The innovative method which has already been published, uses physical wave patterns to cause a spontaneous buckling or wrinkling of the surface. The creation of patterns on nanocellulose has been demonstrated , and many different patterns are now being tested to see which have the best antimicrobial or antibiofilm activity.
Also, Triple-A-COAT partners have been developing ways to make effective coatings, firstly using the unmodified nanocellulose. Nanocellulose can be sprayed onto surfaces using standard equipment, as used for paint spraying. The three types of nanocellulose used in Triple-A-COAT have different physical properties and partners have worked on formulations that give optimal performance for spray coating. Another key requirement is that the coatings adhere well to various surface materials, including glass, metal, plastic and textiles. Nanocellulose itself can stick very well to certain types of material, but for others, extra ingredients may be useful as a linker to obtain a durable coating. Also, cross linking compounds are being used to adjust the coating properties. We are evaluating many different formulations using standard industry methods for coating durability relevant for frequently touched surfaces.
Over the next few months we shall select the best performing formulations for further development and optimisation. This stage of the work will include scaling up of production so that sufficient material is available for the final demonstration in the bus simulation.
At month 18, Triple-A-COAT is still in the process of evaluating its first set of results, and dissemination of results will start shortly. We aim that the project will develop a new platform for antimicrobial coatings for frequently touched surfaces based on nanocellulose, with several different options for materials, antimicrobial functions and coating type. This will enable coatings to be designed for different needs, for example long or short term use, broad spectrum or targeting specific kinds of microorganism.
The coatings technology will be taken forward with industry investment, scale up of production and regulatory approval of the active compounds used. We anticipate the new coatings becoming available from around 5 years after the end of the project.
The coatings technology will be taken forward with industry investment, scale up of production and regulatory approval of the active compounds used. We anticipate the new coatings becoming available from around 5 years after the end of the project.