RU2807836C1 - Antibacterial, anti viral, anti fungal paint materials - Google Patents

Abstract

FIELD: antimicrobial component.

SUBSTANCE: group of inventions can be used for painting surfaces operating under conditions of possible microbial contamination. Variants of antibacterial, antiviral, antifungal paint and varnish material containing a binder, pigment, functional additives and/or filler, solvent and antimicrobial component are proposed. The antimicrobial component is a bicomponent nanoparticle with a Janus nanoparticle structure, in which one part is a metal oxide with an average size of 72±18 nm, the other part is a transition metal with an average size of 25±10 nm.

EFFECT: group of inventions makes it possible to increase the antibacterial, antiviral and antifungal properties of the paint and varnish material.

2 cl, 4 tbl, 8 ex

Description

The invention relates to antimicrobial paint and varnish materials with virucidal activity, including against the SARS-CoV-2 coronavirus, as well as antibacterial and antifungal properties. The claimed invention is intended for painting surfaces operating under conditions of possible microbial contamination with possible use in the form of paint and varnish. Antimicrobial paints and varnishes are a suspension of pigments and fillers in an aqueous polymer dispersion with the addition of various modifying, antimicrobial, antiviral and antifungal additives.

The claimed material in the form of paint is intended for repair and construction work as an independent finishing coating on plasterboard, brick, concrete, plastered, putty surfaces in residential and public buildings. The coating is resistant to washing with mild detergents.

An independent paint and varnish material in the form of varnish is intended for the preventive protection of already finished (painted) surfaces from the spread of pathogenic organisms in crowded places: medical, public and preschool institutions, gyms, clubs, offices, train stations, airports, metro station halls, military barracks, interior surfaces of vehicles. Designed for application on plastered, putty and painted surfaces, brick, cement, concrete, foam concrete, plasterboard, wallpaper, old non-chalking water-dispersion paint, leatherette, metal and plastic surfaces.

A composition is known for producing coatings with bactericidal properties, mainly for paints and varnishes, film formers, impregnations, dry mixtures, which can be used in construction, medicine and various other fields of technology (patent RU 2186810, C09D 5/14, published on 08/10/2002 ). The composition includes a paint and varnish material intended for application to the protected material, and a metal-containing bactericidal component introduced into the paintwork material. Nanostructured metal particles with a lifetime of at least three months in the composition and with a content of nanostructured metal particles from 2×10 ^-6 to 0.3 mol per 1 kg of paintwork materials were used as a metal-containing bactericidal component. The combination of components in a certain ratio allows you to obtain an environmentally friendly coating, used both in children's and medical institutions, and in everyday life, because on its surface it has bactericidal properties that suppress pathogenic bacteria of a wide range of infections.

The disadvantage of the analogue is the relatively short lifetime of nanostructured particles in the composition, as well as the increased possibility of their coagulation during application (for example, by spraying) and the formation of a paint coating, which reduces the biocidal properties of the material. Also, the analogue does not provide evidence of the full effectiveness of potential carriers of bacterial infections - viruses, bacteria, fungi, or the evidence is very weak.

Analogues of the claimed invention are paint and varnish compositions containing nano-sized particles of shungite and silver, with a content of nanoparticles from 0.005 to 1.0% wt. (applications RU 2008126129, C09D 5/00, published 01/10/2010; RU 2008126130, C09D 5/14, published 01/10/2010; RU 2008126123, C09D 5/14, published 10.01. 2010).

The disadvantage of analogues is the possible coagulation of silver nanoparticles during the formation of the paint coating, which reduces the antimicrobial properties of the coating and also shortens the shelf life of the product.

There is a known composition (patent RU 2497856, C09D5/14, published on November 10, 2013), which refers to paint and varnish compositions intended for painting surfaces operating under conditions of possible microbial contamination, selected as a prototype. The paint and varnish composition contains a binder, pigment, functional additives and/or filler, nanostructured silver particles obtained by carrying out a redox reaction using the natural polysaccharide arabinogalactan, and a solvent. The invention ensures the prolongation of the biocidal effect of the paint and varnish coating for a period of up to 5 years and the stability of silver nanoparticles during storage of the paint and varnish composition and the formation of a coating from it.

The disadvantage of the known composition is its low biocidal activity against viruses, in particular the SARS-CoV-2 coronavirus.

The presence of various microorganisms in nature can have a detrimental effect on human health. Recently, there has been increased concern from the scientific community and public health due to the increase in the number of new highly virulent viruses that can cause a pandemic around the world [Phua, J., Weng, L., Ling, L., Egi, M., Lim, C. M., Divatia, J. V., et al. (2020). Intensive care management of coronavirus disease 2019 (COVID-19): challenges and recommendations. The lancet respiratory medicine, 8(5), 506-517. DOI: 10.1016/S2213-2600(20)30161-2]. The coronavirus that causes COVID-19 (Corona Virus Disease 2019 is a severe acute respiratory infection caused by the pandemic coronavirus SARS-CoV-2) is transmitted not only through airborne droplets, but also through various surfaces that can transmit the virus from one person to another . Therefore, there is a need for antimicrobial coatings that will prevent viral transmission. The use of paints and varnishes with antiviral, antibacterial and antifungal properties to protect surfaces in medical institutions, schools, preschools, train stations, airports and other crowded places can help in the fight against the new coronavirus infection.

The objective of the present invention is to develop antimicrobial paint and varnish materials in the form of paint and varnish that have virucidal activity, including against the SARS-CoV-2 coronavirus (severe acute respiratory syndrome-relatedcoronavirus 2 - human pandemic coronavirus), as well as antibacterial and antifungal properties.

The problem is solved by the fact that the claimed invention is presented in the form of variants and contains a binder, pigment, functional additives and/or filler, but unlike the prototype it contains an antimicrobial component consisting of bicomponent nanoparticles having the structure of Janus nanoparticles, in which one part is represented metal oxide with an average size of 72±18 nm, the other part is represented by a transition metal with an average size of 25±10 nm.

By paint and varnish material in the form of paint we mean the declared coating with the following ratio of components, wt%:

binder 10-55

pigment 1.0-20.0

functional additives and/or filler 0.5-55

bicomponent nanoparticles 0.8-1.2

solvent - the rest.

By paint and varnish material in the form of varnish we mean the declared coating with the following ratio of components, wt%:

binder 0.5 - 15

pigment 0.0 - 1.0

functional additives and/or filler 0.5-20

bicomponent nanoparticles 0.8-1.2

solvent - the rest.

Below are examples of specific implementations of the invention using examples of the production of paint and varnish.

Example 1

A sample of paint and varnish material (paint) was obtained in a high-speed dissolver with the sequential introduction of the following components, wt.%:

- water 28.58;

- pigment - 9;

functional additives and filler:

- softener - 0.15;

- dispersant - 0.3;

- rheology and sediment modifier - 0.1;

- cellulose thickener - 0.23;

- associative thickener - 0.76;

- container preservative - 0.01;

- antifreeze - 3;

- coalescent - 0.75;

- neutralizer - 0.15;

- binder - 15;

- defoamer - 0.2;

- filler - 40.79;

- bicomponent nanoparticles - 0.8.

Bicomponent nanoparticles were introduced into a water-dispersed paint and varnish material in the form of an aqueous suspension. The average size of the metal oxide in bicomponent nanoparticles was 76 ± 11 nm, and that of the transition metal was 24 ± 9 nm.

Example 2

A sample of paint and varnish material (paint) was obtained in a high-speed dissolver with the sequential introduction of the following components, wt.%:

- water - 20.39;

- binder - 50;

- pigment - 15;

- functional additives and filler:

- softener - 0.15;

- dispersant - 0.8;

- associative thickener - 3;

- container preservative - 0.01;

- antifreeze - 3;

- coalescent - 1.2;

- defoamer - 0.25;

- filler - 5;

- bicomponent nanoparticles - 1.2.

Bicomponent nanoparticles were introduced into a water-dispersed paint and varnish material in the form of an aqueous suspension. The average size of the metal oxide in bicomponent nanoparticles was 76 ± 11 nm, and that of the transition metal was 24 ± 9 nm.

Example 3

A sample of paint and varnish material (varnish) was obtained in a high-speed dissolver with the sequential introduction of the following components, wt.%:

- water - 92.51.

- binder - 2;

- functional additives and filler:

- softener - 0.15;

- dispersant - 0.4;

- rheology and sediment modifier - 0.05;

- cellulose thickener - 0.18;

- associative thickener - 0.6;

- container preservative - 0.01;

- antifreeze - 3;

- coalescent - 0.1;

- neutralizer - 0.1;

- defoamer - 0.2;

- bicomponent nanoparticles - 0.8.

Bicomponent nanoparticles were introduced into the paint and varnish composition in the form of an aqueous suspension. The average size of the oxide component in bicomponent nanoparticles is 71±7 nm, the transition metal - 21±5 nm.

Example 4

A sample of paint and varnish material (varnish) was obtained in a high-speed dissolver with the sequential introduction of the following components, wt.%:

- water 91.91

- binder - 2.1;

- functional additives and filler:

- softener - 0.15;

- dispersant - 0.4;

- rheology and sediment modifier - 0.05;

- cellulose thickener - 0.18;

- associative thickener - 0.6;

- container preservative - 0.01;

- antifreeze - 3;

- coalescent - 0.1;

- aqueous technical ammonia - 0.1;

- defoamer - 0.2;

- bicomponent nanoparticles - 1.2.

Bicomponent nanoparticles were introduced into the paint and varnish composition in the form of an aqueous suspension. The average size of the oxide component in bicomponent nanoparticles is 71±7 nm, the transition metal - 21±5 nm.

Example 5

The study of the virucidal activity of the coating (paint) obtained according to example 2 against the human pandemic coronavirus SARS-CoV-2 on an in vitro cell model was carried out at the Testing Center of the Federal State Budgetary Institution "National Center for Epidemiology and Mathematics named after. N.F. Gamaleya" of the Russian Ministry of Health.

The declared antimicrobial material (paint) and a control sample (CS) were applied with a bone/spray bottle to the bottom of the wells of a 12-well plate so that the paint and CS completely covered the bottom of the wells and dried at a temperature of (20±2)°C until the paint layer was completely dry . A paint and varnish material of the same composition, but without nanoparticles, was used as a CO. Virus control (CV) wells were not coated with paint.

The continuous African green monkey ( Chlorocebus aethiops ) kidney cell line Vero-E6, provided in the experiments, was used. All-Russian Collection of Cell Cultures at the Federal State Budgetary Institution “NICEM named after. N.F. Gamaleya" of the Russian Ministry of Health. Culture media were prepared according to package instructions. Vero-E6 cells were placed into 96-well flat-bottomed culture plates, 12,000 cells/well in a volume of 100 μl of freshly prepared PS medium. They were cultured at a temperature of 37°C in an atmosphere of 5% CO ₂ . The studies used the human coronavirus strain SARS-CoV-2 with an infectious activity of 10 ⁶ TCID ₅₀ /ml (a dose of the virus that causes a cytopathic effect in 50% of wells with an infected cell culture) for Vero-E6 cells, deposited in the State Collection of Viruses of the Russian Federation, Federal State Budgetary Institution " NICEM named after. N.F. Gamaleya" of the Ministry of Health of Russia under number No. 1301/2 GKV.

Before the start of the study, the wells of a 12-well culture plate with applied paint and KO were irrigated with 79% ethyl alcohol and dried. Then, 400 μl/well of a virus-containing suspension of SARS-CoV-2 with an infectious activity of 10 ⁶ TCID ₅₀ / ml was pipetted into the wells of the plate and distributed evenly over the surface of the well with the tip of the pipette. The plate with the virus was incubated at a temperature of (20±2)°C and a relative humidity of 50-60% for 2 hours. After incubation, the contents of the wells of a 96-well test plate with cells were prepared and a series of serial 10-fold dilutions were prepared. The test plates were incubated in an atmosphere of 5% CO ₂ at 37°C for 96 hours.

The virucidal activity of the material was assessed by the maximum reduction in the value of the infectious viral dose in the experiment compared to the control, expressed in decimal logarithms (Δlg _max ).

The assessment of the virucidal activity of the material was taken into account by the decrease in the infectious titer of the virus in the Vero-E6 cell culture according to the CPE (cytopathic effect). The results are presented in Table 1.

Table 1 - Virucidal properties of materials against the SARS-CoV-2 virus in Vero-E6 cell culture Material TCID ₅₀ , lg Virus control, lg Maximum reduction in the value of the infectious viral dose in the experiment compared to the control, Δlg _max Dye 0 7.0 7.0 KO 5.25 7.0 1.75

The results of studies carried out during incubation of a virus-containing suspension with a coating based on paint and CO for 2 hours at a temperature of (20±2)°C, relative air humidity of 50-60% showed that the coating (paint), including nanoparticles with antimicrobial properties in concentration 1.2% wt. completely inactivates the SARS-CoV-2 virus by 7.0 lg, while the coating (CO) without nanoparticles reduces the amount of virus by 1.75 lg.

Thus, the declared antimicrobial material (paint), which contains nanoparticles with antimicrobial properties, meets the criteria for virucidal activity against the SARS-CoV-2 coronavirus in accordance with MU 3.5.2431-08 “Study and evaluation of the virucidal activity of disinfectants.”

Example 6

Preparation of painted test surfaces.

Smooth wooden surfaces measuring 5x5 cm, made from unpainted hardwood lumber (GOST 2695), meeting the requirements of Guideline R.4.2.3676-20 were used as test surfaces to study the antibacterial, antifungal and antiviral activity of antimicrobial coatings. Antimicrobial coatings in the form of paint, obtained according to examples 1 and 2, or varnish, obtained according to examples 3 and 4, were applied to the test surfaces with a bone/spray gun, and dried until the paint layer was completely dry. Painted test surfaces (research objects) were sterilized at 121±3°C in a 2540MK steam sterilizer, TuttnauerCo, complies with GOST 17726.

Virucidal activity of materials against the vaccinia virus.

To evaluate the virucidal activity of materials, paint (according to example 2) and varnish (according to example 4) were used. A phosphate-citrate solution of 0.004 M, pH 7.2-7.4, was used as a solvent for the recovery of the vaccinia virus SOP lyophilisate and the solution used for washing samples to extract the virus.

To study the virucidal activity of materials based on paint and varnish, a virus-containing material was used, SOP of the vaccinia virus p.04, specific activity of SOP p.04 according to the passport (4.5±0.9)×10 ⁸ OFU/ml.

To assess virucidal activity, 0.2 ml of virus-containing liquid was applied to each painted test surface. The samples were incubated at 37°C and 100% relative humidity for 21 hours in a CO ₂ incubator (MSO-20A/C). After the time had elapsed, the virus was removed from the surface of the samples by washing in 20 ml of a 0.004 M phosphate-citrate solution, pH 7.2-7.4, and shaking for 15 minutes. To test for virus content, 5 ml of washing liquid was taken. The results of assessing the virucidal activity of coatings against the vaccinia virus are given in Table 2.

Table 2 - Virucidal activity of materials, expressed in a decrease in the content of vaccinia virus after 24 hours of exposure Coating Total amount of virus Viral clearance, lg Applied to test surface After contact with the test surface OOE/0.2 ml lg OOE/0.2 ml lg Paint (according to example 2) 1.74×10 ⁸ 8.2 less than 10 ² less than 2 more than 6.2 Varnish (according to example 4) 1.74×10 ⁸ 8.2 5.6×10 ³ 3.7 4.5

Thus, the declared antimicrobial materials in the presented versions, containing nanoparticles with antimicrobial properties, meet the criteria for virucidal activity against the vaccinia virus in accordance with MU 3.5.2431-08 “Study and evaluation of the virucidal activity of disinfectants.”

Example 7

Antibacterial activity of materials .

To evaluate the antibacterial activity of the material in the form of paint (according to example 1) and varnish (according to example 3), painted test surfaces were prepared as shown in example 6.

Nutrient medium for the cultivation of bacteria Mueller-Hinton agar (Himedia M173-500G) was prepared immediately before the study according to the instructions on the package.

To study the antibacterial activity of the materials, the bacteria Staphylococcus aureus (ATCC item no. 6538-P) and MRSA Methicillin-resistant Staphylococcus aureus (item 806) were used.

Ampules with microorganisms were opened in a laminar flow hood and inoculated into test tubes with a nutrient medium. After 18-20 hours of incubation at a temperature of 37±1°C, cultures were sown on Petri dishes with agar to isolate typical colonies. After 24 h of incubation, the cultures were subcultured into tubes with agar slants and grown for 18 ± 3 h at 37 ± 1°C. To prepare the inoculum, the prepared culture was washed off from the agar slant with 5-10 ml of sterile sodium chloride solution 0.9% by weight. The cell concentration was 2×10 ⁸ CFU/ml.

0.25 ml of a suspension of a test culture of Staphylococcus aureus or MRSA bacteria was applied to each painted test surface and carefully distributed over the surface using a sterile spatula. After 6 hours of exposure, the samples were placed in sterile containers containing 10 ml of sterile sodium chloride solution 0.9% wt., and shaken for 10 minutes (Biosan PSU-20i shaker). Then the washing liquid was inoculated onto solid nutrient media and kept in an incubator (Binder BD53) at a temperature of 37±1°C for 24 hours. The antibacterial activity of the coatings was assessed by calculating the percentage reduction in microbial contamination of the test sample compared to the control. The results of assessing the antibacterial activity of the material are shown in Table 3.

Table 3 - Antibacterial activity of materials Material Microorganisms CFU/ml R ,% Dye
(according to example 1) S. aureus 0.10×10 ³ ±0.00×10 ³ 99.9998±0.0000 MRSA 0.33×10 ³ ±0.05×10 ³ 99.9993±0.0001 Varnish
(according to example 3) S. aureus 5.17×10 ³ ±0.12×10 ³ 99.9897±0.0002 MRSA 2.56×10 ³ ±0.35×10 ³ 99.9948±0.0029

Thus, the antimicrobial material, which contains nanoparticles with antimicrobial properties, showed high antibacterial activity against S. Aureus and MRSA after 6 hours of exposure.

Example 8

Antifungal activity of materials.

To evaluate the antifungal activity of a material based on paint (according to example 2) and varnish (according to example 4), painted test surfaces were prepared as shown in example 6. Nutrient medium Sabouraud Agar (FBUN State Scientific Center for Applied Microbiology and Biotechnology) was prepared immediately before the research according to the instructions on the package.

To evaluate the antifungal activity of the material, Candida albicans (245 pcs.) was used as test microorganisms.

Ampoules with microorganisms were opened in a laminar flow hood and inoculated into tubes with Sabouraud agar. After 18-20 hours of incubation at a temperature of 37±1°C, cultures were sown on Petri dishes with Sabouraud agar to isolate typical colonies. After 48 hours of incubation, the Candida albicans culture was subcultured into tubes with Sabouraud agar slants and grown for 45±3 hours at 27±1°C. To prepare the inoculum, the prepared culture was washed off the agar slant with 5-10 ml of sterile sodium chloride solution 0.9% by weight. The cell concentration was 2×10 ⁸ CFU/ml.

0.25 ml of Candida albicans test culture suspension was applied to each painted test surface and carefully distributed over the surface using a sterile spatula. After 6 hours of exposure, the samples were placed in sterile containers containing 10 ml of sterile sodium chloride solution 0.9% wt., and shaken for 10 minutes (Biosan PSU-20i shaker). Then the washing fluid was inoculated onto solid nutrient media and kept in an incubator (Binder BD53) at a temperature of 27±1°C for 45±3 hours. Activity was assessed by calculating the percentage reduction in microbial contamination of the test sample compared to the control. The results of assessing the antifungal activity of coatings are shown in Table 4.

Table 4 - Antifungal activity of materials Material Microorganisms CFU/ml R ,% Paint (according to example 2) C.albicans 0.43×10 ³ ±0.06×10 ³ 99.9991±0.0001 Varnish (according to example 4) C. albicans 1.03×10 ³ ±0.12×10 ³ 99.9979±0.0002

Thus, antimicrobial materials containing nanoparticles with antimicrobial properties showed high antifungal activity against C. albicans after 6 hours of exposure.

The claimed materials, sold in the form of paint and varnish, are intended to protect surfaces in crowded areas for preventive protection against the spread of pathogenic microorganisms. The materials are resistant to cleaning and disinfecting solutions.

Claims (12)

1. Antibacterial, antiviral, antifungal paint and varnish material containing a binder, pigment, functional additives and/or filler, characterized in that it contains an antimicrobial component consisting of bicomponent nanoparticles having the structure of Janus nanoparticles, in which one part is represented by a metal oxide with an average size 72±18 nm, the other part is represented by a transition metal with an average size of 25±10 nm, with the following ratio of components, wt.%: binder 0.5 - 15 pigment 0.0 – 1.0 functional additives and/or filler 0.5 - 20 bicomponent nanoparticles 0.8-1.2 solvent the rest. 2. Antibacterial, antiviral, antifungal paint and varnish material containing a binder, pigment, functional additives and/or filler, characterized in that it contains an antimicrobial component consisting of bicomponent nanoparticles having the structure of Janus nanoparticles, in which one part is represented by a metal oxide with an average size 72±18 nm, the other part is represented by a transition metal with an average size of 25±10 nm, with the following ratio of components, wt.%: binder 10-55 pigment 1.0 – 20.0 functional additives and/or filler 0.5 - 55 bicomponent nanoparticles 0.8-1.2 solvent the rest.