ANTIMICROBIAL POLYMERIC COMPOSITION

Abstract

Polymeric composition having antimicrobial activity, said composition being a polymeric salt of a anionic polystyrene sulfonate and a cationic component, wherein said cationic component is selected from the group consisting of benzalkonium cations and positively charged micellar derivatives comprising benzalkonium cations and a silver complex. The composition may be included in alcoholic solution, that may be used for producing antimicrobial and antiviral coatings for objects and hand sanitizer gels.

Claims

1. A polymeric composition having antimicrobial activity, said composition being a polymeric salt of anionic polystyrene sulfonate and a cationic component, wherein said cationic component is selected from the group consisting of benzalkonium cations and positively charged micellar derivative, said positively charged micellar derivative containing benzalkonium cations and a silver complex.

2. The polymeric composition according to claim 1, wherein said cationic component is a positively charged micellar derivative, said positively charged micellar derivative containing benzalkonium cations and a silver complex.

3. The polymeric composition according to claim 1, wherein said benzalkonium cations and said positively charged micellar derivatives are electrostatically bonded to sulfonate anions comprised in said anionic polystyrene sulfonate.

4. The polymeric composition according to claim 1, wherein said silver complex is a complex of bi-coordinated silver having the formula:
Ag.sup.+[(MPA.sup.2?).sub.2].sup.3? wherein Ag.sup.+ is a silver cation and MPA.sup.2? is the anionic bivalent form of 2-mercapto-4-methyl-5-thiazolacetic acid.

5. The polymeric composition according to claim 1, wherein said antimicrobial activity comprises an antiviral activity.

6. The polymeric composition according to claim 5, wherein said antiviral activity comprises an antiviral activity towards a member of the family Coronaviridae.

7. The polymeric composition according to claim 6, wherein said member of the family Coronaviridae is human Coronavirus 229E or SARS-Cov-2.

8. (canceled)

9. (canceled)

10. (canceled)

11. An alcoholic solution containing the polymeric composition according to claim 1.

12. (canceled)

13. A method of preparing a coating, the method comprising: providing the polymeric composition of claim 1, optionally combining the polymeric composition with an alcoholic solution, and using the polymeric composition to produce either an antimicrobial and antiviral coating suitable for coating objects or a coating for filters for air decontamination devices and air conditioning devices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention will be better understood and implemented with reference to the attached drawings which illustrate an exemplary and non-limiting form of implementation, of which:

[0015] FIG. 1 is a graph showing the FT-IR spectrum of an embodiment of the polymeric composition according to the invention;

[0016] FIG. 2 is a photograph of a Petri dish, showing the antimicrobial activity of an acqueous solution of the sodium salt of a silver complex contained in the polymeric composition according to the invention;

[0017] FIG. 3 is a photograph of a Petri dish, showing the antimicrobial activity of micellar derivatives containing the silver complex of FIG. 2 and benzalkonium;

[0018] FIGS. 4A and 4B are two photographs of Petri dishes, showing the antimicrobial activity of two embodiments of the polymeric compositions according to the invention;

[0019] FIG. 5 is a graph showing the increase in threshold cycles (Ct) required to detect RNA of SARS-Cov-2 treated with the silver complex of FIG. 2 and then inoculated in cells sensitive to the virus;

[0020] FIG. 6 is a graph showing the number of times difference in the viral replication of SARS-Cov-2, treated with the sodium salt of the silver complex of FIG. 2, compared to untreated SARS-Cov-2.

[0021] FIG. 7 is a graph showing the increase in threshold cycles (Ct) required to detect RNA of Coronavirus 229E treated with an embodiment of the polymeric composition according to the invention, containing the sodium salt of the silver complex of FIG. 2 and benzalkonium, and then inoculated in cells sensitive to the virus;

[0022] FIG. 8 is a graph showing the number of times difference in viral replication of Coronavirus 229E, treated with the embodiment of the polymeric composition of FIG. 7, compared to untreated Coronavirus 229E;

[0023] FIG. 9 is a graph showing the increase in threshold cycles (Ct) required to detect RNA of SARS-Cov-2 treated with the embodiment of the polymeric composition of FIG. 7 and then inoculated in cells sensitive to the virus;

[0024] FIG. 10 is a graph showing the number of times difference in viral replication of SARS-Cov-2, treated with the embodiment of the polymeric composition of FIG. 7;

[0025] FIG. 11 is a graph showing the increase in threshold cycles (Ct) required to detect RNA of SARS-Cov-2 treated with another embodiment of the polymeric composition according to the invention and then inoculated in cells sensitive to the virus;

[0026] FIG. 12 is a graph showing the number of times difference in the viral replication of SARS-Cov-2, treated with the other embodiment of the polymeric composition according to the invention, compared to untreated SARS-Cov-2.

DETAILED DESCRIPTION OF THE INVENTION

[0027] In the present description, as well as in the attached claims: [0028] the term silver cation and the corresponding chemical symbol Ag.sup.+ can be used interchangeably; [0029] the term silver complex is defined as a complex of a silver cation, having the corresponding chemical symbol Ag.sup.+, and one or more anions, preferably an organic anion, such as one or more ligands, preferably one or more anionic organic ligands. [0030] the terms benzalkonium ion and benzalkonium cation and the symbol Bz.sup.+ can be used interchangeably; [0031] the terms polystyrene sulfonate and poly(sodium 4-styrene sulfonate) and the abbreviation PSS can be used interchangeably; [0032] the term antimicrobial defines the ability of a substance, or a mixture of substances, to kill microorganisms in general and/or prevent their growth; [0033] the term antiviral defines the ability of a substance, or a mixture of substances, to kill viruses (virucidal activity).

[0034] In one embodiment, the polymeric composition according to the invention is a polymeric salt of anionic polystyrene sulfonate (PSS) and benzalkonium cations (Bz.sup.+), wherein the benzalkonium cations are bonded to the PSS matrix.

[0035] Since in anionic PSS the acidic sulfonic groups (SO.sub.3H) are deprotonated to sulfonate anions (SO.sup.3?), the benzalkonium cations are electrostatically bonded to the sulfonate anions.

[0036] In another embodiment, the polymeric composition according to the invention is a polymeric salt of anionic polystyrene sulfonate (PSS) and positively charged micellar derivatives containing benzalkonium cations and a silver complex, wherein the positively charged micellar derivatives are electrostatically bonded to the sulfonate anions of the PSS matrix.

[0037] Therefore, the polymeric composition according to the invention is a polymeric salt of anionic polystyrene sulfonate (PSS) and a cationic component, wherein the cationic component is selected from the group consisting of benzalkonium cations and positively charged micellar derivatives containing benzalkonium cations and a silver complex.

[0038] The micellar derivatives can be prepared starting from a sodium salt of bi-coordinated silver complex having the formula Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3?, wherein MPA.sup.2? is the anionic bivalent form of 2-mercapto-4-methyl-5-thiazolacetic acid (MPA). MPA.sup.2? is obtained through deprotonation of carboxylic groups (COOH) and mercapto (SH) of MPA. The preparation of said sodium salt of the bi-coordinated silver complex is described in Example 1 below. The sodium salt of the bi-coordinated silver complex is then reacted with benzalkonium chloride, as described in Example 2 below.

[0039] With the purpose of facilitating the understanding of the invention, but without limiting its scope, the following Examples are described: preparation of a sodium salt of bi-coordinated silver complex having the formula Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? (Example 1); preparation of micellar derivatives of (Bz.sup.+).sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.?3 (Example 2); preparation of polymeric compositions (polymeric salts M-1 and M-2) according to the invention (Example 3); evaluation of the antimicrobial activity of the sodium salt of bi-coordinated silver complex having the formula Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? in aqueous solution (Example 4); evaluation of the antimicrobial activity of micellar derivatives of (Bz.sup.+).sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.?3 in aqueous solution (Example 5); evaluation of the antimicrobial activity of M-1 and M-2 (Example 6); evaluation of the antiviral effectiveness of Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? in aqueous solution towards SARS-Cov2 (Example 7); evaluation of the antiviral effectiveness of M-1 towards Coronavirus 229E (Example 8); evaluation of the antiviral effectiveness of M-1 towards SARS-Cov2 (Example 9); evaluation of the antiviral effectiveness of M-2 towards SARS-Cov2 (Example 10).

[0040] With reference to the described Examples, all chemical products were bought from Sigma-Aldrich. Elemental analysis (C, H, N) was carried out with a LECO-CHN analyser. Silver was determined by plasma atomic absorption spectroscopy with an instrument Perkin Elmer Optima 3100 XL. FT-IR spectra were recorded with a spectrometer FT-IR Bruker Vertex 70 in diffuse reflectance mode and dispersing the powder of chemical products in KBr. Dimensional analysis and Zeta potential were obtained with a Z-sizer Malvern analyser.

EXAMPLE 1

Preparation of Sodium Salt of Bi-Coordinated Silver Complex Na.SUP.+3.[Ag.SUP.+.(MPA.SUP.2?.).SUB.2.].SUP.3?

[0041] 12.36 g of a 1M NaOH solution in water were added to an amount of 1.135 g of MPA. 186.5 g of distilled water were then added and the solution was maintained under stirring for 5 min. Finally, 100 g of aqueous solution containing 0.51 g of AgNO.sub.3 were added, yielding a yellow solution which was maintained under stirring for another 30 min. The salt of bi-coordinated silver complex Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? was precipitated by addition of an acetone excess, filtered and air dried. Ag.sup.+%=0.108%. Elemental analysis: calculated for Na.sub.3AgC.sub.12N.sub.2S.sub.4O.sub.4H.sub.10; C 26.14; N, 5.08; H, 1.83; Ag, 19.57. Found: C, 25.87; N 5.0; H 1.88; Ag 19.46.

[0042] Elemental analysis and spectroscopic data for the silver complex are coherent with the presence of two anionic ligands MPA.sup.2? coordinated to ions Ag.sup.+. The -IR spectrum of MPA shows a strong CO stretching band of the carboxylic group at 1704?2 cm.sup.?1 and a stretching band SH at 2555?2 cm.sup.?1. The SH stretching band disappears in the anionic silver complex, which is coherent with sulphur coordination to Ag.sup.+. Intense bands due to asymmetric and symmetric stretching modes of carboxylate appear at 1580?2 cm.sup.?1 e 1386?2 cm.sup.?1, respectively.

EXAMPLE 2

Preparation of Micellar Derivatives (M-0) of (Bz.SUP.+.).SUB.3.[Ag.SUP.+.(MPA.SUP.2?.).SUB.2.].SUP.?3

[0043] Benzalkonium (Bz) is a mixture of quaternary ammonium salts (cationic surfactants) and, more specifically, is a mixture of alkyl-benzyl-dimethyl-ammonium chlorides, in which the alkyl group varies from octyl (C.sub.8H.sub.17) to octadecil (C.sub.18H.sub.37). The average molecular weight of benzalkonium chloride salt is 370 g. Adding a small excess of benzalkonium chloride to an aqueous solution of Na.sup.+.sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? (salt of bi-coordinated silver complex) of Example 1, the uncharged salt Bz.sup.+).sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.?3 can be suitably precipitated. The addition of benzalkonium chloride to the anionic silver complex [Ag.sup.+(MPA.sup.2?).sub.2].sup.3? in water gives rise to the neutralization of the negative charge with formation of a precipitate which is coherent with the stoichiometry (Bz.sup.+).sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.?3 (salt of the anionic silver complex).

[0044] Through further addition of an excess of benzalkonium chloride to the precipitated salt in water, (Bz.sup.+).sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.?3 is dissolved by formation of positively charged micellar derivatives (hereinafter referred to as M-0), caused by the excess of surrounding Bz.sup.+ cations, with a dimensional distribution in the range 10-500 nm.

[0045] On the laboratory scale, the above-described micellar derivatives can be prepared by addition of 100 g of a 50% benzalkonium chloride solution in water to 100 g of the Na.sup.+.sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? solution with silver at 0.108% (prepared as described in Example 1).

EXAMPLE 3

Preparation of Polymeric Compositions (Polymeric Salts M-1 and M-2) According to the Invention

[0046] Polymeric salts (neutral polymers) of positively charged micellar derivatives of (Bz.sup.+).sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.?3 (hereinafter referred to as M-1) of Example 2 and polymeric salts (neutral polymers) of benzalkonium ions (hereinafter referred to as M-2) were obtained as precipitates in distilled water by addition of poly(sodium 4-styrene sulfonate) (PSS) with an average molecular weight of 70,000 g. Practically, the polymeric salt M-1 can be obtained by adding PSS to the micellar derivatives of Example 2, said addition being performed with a quantity by weight of PSS equal to about 60% of the weight of benzalkonium chloride, while the polymeric salt M-2 can be obtained by adding an excess of benzalkonium chloride to an aqueous solution of PSS. Similarly to what described above with reference to M-1, that corresponds to an addition of a quantity by weight of PSS equal to about 60% of the weight of benzalkonium chloride.

[0047] The neutral precipitated polymers M-1, containing PSS, [Ag.sup.+(MPA.sup.2?).sub.2].sup.?3 and Bz.sup.+ ions electrostatically bonded to sulfonate groups, and M-2, containing PSS and Bz+ ions electrostatically bonded to sulfonate groups, were separated from the aqueous solutions by filtration and were dried at 50? C. both M-1 and M-2 are insoluble in water, but are suitably soluble in alcoholic solvents. Thus, the polymeric solids were dissolved in isopropanol or ethanol to obtain a solution of M-1, containing 1% Bz, 0.62% PSS and 0.002% Ag, and a solution of M-2, containing 1% Bz and 0.62% PSS.

[0048] The solutions of M-1 in alcohol are composed by micellar aggregates (micellar derivatives) with diameters in the order of 10 nm and zeta potential of ?3.9 mV. A minority of aggregates with diameter in the order of 50 and 500 nm was also observed. Infrared spectra of the polymeric solids M-1 and M-2 are similar, with vibrational bands concordant with the overlap of the intense bands of benzalkonium and PSS. As example, the FT-IR spectrum of M-1 is shown in FIG. 1.

EXAMPLE 4

Evaluation of the Antimicrobial Activity of the Sodium Salt of Bi-Coordinated Silver Complex Na.SUP.+3.[Ag.SUP.+.(MPA.SUP.2?.).SUB.2.].SUP.3? in aqueous solution.

[0049] The antimicrobial activity of an aqueous solution at pH 8.3 of Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? with an ionic concentration of [Ag+]=0.1% was tested against the following blend of microorganism strains (bought from Diagnostic International Distribution S.p.A): Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 10536, Enterococcus hirae ATCC 10541 e Candida albicans ATCC 10231. For each microbial strain, the concentration of the blend was in the range 1.5?10.sup.12?5?10.sup.12 unity forming colonies (UFC). A volume of 100 ?l of the blend was seeded in Petri dishes containing a non-selective culture medium TSA (Tryptone Soya Agar) and a sample of 100 ?l of said aqueous solution of Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? was put in the centre of each Petri dish in contact with the microbial blend. The Petri dishes were then incubated at 37? C. for 24 h. FIG. 2 shows the presence of a zone of inhibition (of the microbial growth) of circa 3 cm in one of the incubated Petri dishes, a zone which confirms the antimicrobial activity of the aqueous solution.

EXAMPLE 5

Evaluation of the Antimicrobial Activity of Micellar Derivatives of (Bz.SUP.+.).SUB.3.[Ag.SUP.+.(MPA.SUP.2?.).SUB.2.].SUP.?3 .(M-0) in Aqueous Solution

[0050] The antimicrobial activity of a diluted aqueous solution of micellar derivativescontaining benzalkonium at 1% and silver at 0.0025%was tested against the following blend of microorganism strains (bought from Diagnostic International Distribution S.p.A): Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 10536, Enterococcus hirae ATCC 10541 e Candida albicans ATCC 10231.

[0051] Blends of the different strains of microorganisms were prepared, having concentrations between 1.5?10.sup.12 and 5.5?10.sup.12 UFC for each strain. A sample of 100 ?l of the aqueous solution of micellar derivatives was deposited at the centre of Petri dishes. 50 ?l of the microbial blend were then deposited on the aqueous solution of micellar derivatives and left in contact with the latter for 5 minutes. Non-selective culture medium TSA (Tryptone Soya Agar) was then added and the dishes were then incubated at 37? C. for 24 h. After incubation, the dishes were examined in order to evaluate microbial proliferation (formation of colonies). As shown in FIG. 3, while in the control Petri dish (Petri dish on the left, containing only the microorganisms strains) there was an homogenous microbial proliferation, in the Petri dish containing also the sample of aqueous solution of micellar derivatives no microbial proliferation was observed, which indicated a complete inactivation of microbial species.

[0052] Therefore, the analytical result obtained confirms that the diluted aqueous solution of micellar derivatives (containing benzalkonium at 1% and silver at 0.0025%) is able to inhibit the growth of about 10.sup.11 UFC Gram-positive bacteria, Gram-negative bacteria and of the fungal species Candida albicans.

EXAMPLE 6

Evaluation of the Antimicrobial Activity of M-1 and M-2

[0053] The antimicrobial activity of M-1 (alcoholic solution containing Bz 1%, Ag 0.002%, PSS 0.62% and the rest to 100 being ethanol or isopropanol) and M-2 (alcoholic solution containing Bz 1%, PSS 0.62% and the rest to 100 being ethanol or isopropanol) was tested against the following microorganisms strains (bought from Diagnostic International Distribution S.p.A.): Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 10536, Enterococcus hirae ATCC 10541 and Candida albicans ATCC 10231.

[0054] Blends of the different strains of microorganisms were prepared, having concentrations expressed as UFC between 1.5?10.sup.12 e 5.5?10.sup.12 for each species. Samples of 100 ?l of the alcoholic solutions of M-1 and M-2 were deposited at the centre of Petri dishes and dried for 2 h in an oven at 37?? C. 100 ?l of the microbial blend were then added and left in contact with M-1 and M-2 for 5 minutes. Non-selective culture medium TSA (Tryptone Soya Agar) was added and the Petri dishes were then incubated at 37? C. for 24 h. After incubation, the dishes were examined in order to evaluate microbial proliferation (colonies formation). As shown in FIGS. 4A and 4B, while in the control Petri dish (containing only the microorganisms strains) there was an homogenous microbial proliferation, in the Petri dish containing M-1 (FIG. 4A, right) and M-2 (FIG. 4B, left) no proliferation was observed, which indicated a complete inactivation of 1.5-5?10.sup.11 UFC Gram-positive and Gram-negative bacteria, as well as of the fungal species Candida albicans.

EXAMPLE 7

Evaluation of the Antiviral Effectiveness of Na.SUP.+3.[Ag.SUP.+.(MPA.SUP.2?.).SUB.2.].SUP.3? in Aqueous Solution Towards SARS-Cov2

[0055] The experiments were performed in a BSL-3 facility at the University of Ferrara (Italy). An aqueous solution containing Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? with a concentration of Ag+ of 0.108% was sprayed onto disposable plastic Petri dishes and left to dry in a biosafety cabinet. Then, 1 ml of SARS-Cov-2 inoculum was incubated on each Petri dish for 5 minutes. After treatment, the virus for used to inoculate sensitive cells (VeroE6; ATCC? CRL-1586?). Cellular supernatants were collected at 24, 48, and 72 hours post-infection to evaluate viral replication. As a positive control a untreated viral inoculum was used. The replication of SARS-Cov-2 was estimated by qRT-PCR after extraction of RNA. The cytopathic effect in the infected cells was assessed by optical microscopy (Nikon inverted microscope).

[0056] Analytical results were expressed as threshold cycle (Ct), namely the number of cycles of qRT-PCR required for the fluorescent signal to exceed the threshold value, a number which is inversely proportional to the amount of viral RNA. In other words, Ct is the cycle in which the target becomes detectable. The average Ct is shown in the graph of FIG. 5, in which NT stands for non-treated (i.e. control) and Ag stands for treated with the aqueous solution containing Na.sup.+.sub.3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3?.

[0057] Table 1 below shows the replication of SARS-Cov2 in VeroE6 cells after treatment with aqueous solution containing Ag, a replication which is expressed as logarithmic difference between the untreated control. The pre-treatment of SARS-Cov2 with the aqueous solution containing Ag caused a significant decrease of 0.91 logarithms of the viral charge at 24 h post-infection (hpi), a decrease of 0.57 logarithms at 48 pci, while the reductions observed at a time more distant from the infection are not significant:

TABLE-US-00001 TABLE 1 Logarithmic Samples ?Ct difference Aqueous solution containing Ag 24 hpi 3.04 ?0.91 Aqueous solution containing Ag 48 hpi 1.91 ?0.57 Aqueous solution containing Ag 72 hpi 0.61 ?0.18

[0058] The graph of FIG. 6 represents the difference in viral replication after treatment with the solution containing Ag compared to the untreated virus. Concomitantly, a morphologic analysis of the infected cells was performed. The cells infected with the virus treated with the solution containing Ag exhibited a lower cytopathic effect compared to the cells infected with the untreated virus. This evidence occurred 48 hours post-infection. In conclusion, incubation of SARS-ov2 for 5 minutes on surfaces that were treated with an aqueous solution containing Ag led to a logarithmic reduction of 0.91 logarithms at 24 hours post-infection. This reduction is responsible for a decrease in the cytopathic effect, as highlighted by morphologic observation at 48 hours post-infection.

[0059] Similar experiments were carried out on diluted aqueous solutions containing Na.sup.+3[Ag.sup.+(MPA.sup.2?).sub.2].sup.3? with a concentration of Ag.sup.+ of 0.002% and showed that the incubation of SARS-Cov2 for 5 minutes on surfaces treated with an aqueous solution containing Ag produced a reduction of 0.82 logarithms of the viral charge at 24 hours post-infection. The reduction was responsible for a small decrease of the cytopathic effect, as highlighted by morphologic observation at 72 hours post-infection.

EXAMPLE 8

Evaluation of the Antiviral Effectiveness of M-1 Towards Coronavirus 229E

[0060] The experiments were performed in a BSL-3 facility at the University of Ferrara (Italy). A solution in isopropanol of M-1 having the same composition reported in Example 6 (Bz 1%, Ag 0.002%, PSS 0.62%) was sprayed onto disposable plastic Petri dishes and left to dry in a biosafety cabinet. Then, 1 ml of human Coronavirus 229E (ATCC: VR-740) was incubated in each Petri dish for 5 minutes. After treatment, the virus was used to inoculate human sensitive cells (MRC-5, ATCC: CCL-171). Cellular supernatants were collected at 24 and 48 hours post-infection to evaluate viral replication. As a positive control a untreated viral inoculum was used. Viral replication was estimated by qRT-PCR after extraction of RNA.

[0061] Analytical results are expressed as threshold cycles (Ct), namely the cycle in which the target becomes detectable. Average Ct is shown in the graph of FIG. 7, in which nt stands for non-treated (i.e. control) and M-1 stands for treated with M-1.

[0062] Table 2 below shows the replication of Coronavirus 229E in MRC-5 cells after treatment with M-1, replication which is expressed logarithmic difference compared to the untreated control. The pre-treatment of Coronavirus 229E with M-1 caused a reduction of 6.1 logarithms of the viral charge at 24 hours post-infection and a reduction of 6.5 logarithms at 48 hours post-infection:

TABLE-US-00002 TABLE 2 Logarithmic N. times Samples difference difference Untreated 24 h 0 0 Untreated 48 h 0.4 1 M-1 24 h 6.1 ?1.31 * 10.sup.6 M-1 48 h 6.5 ?3.38 * 10.sup.6

[0063] The graph of FIG. 8 represents the difference in viral replication after treatment with M-1 compared to the untreated virus. In conclusion, treatment of Coronavirus 229E with M-1 is able to cause a reduction of 6 logarithms of the viral infectivity.

EXAMPLE 9

Evaluation of the Antiviral Effectiveness of M-1 Towards SARS-Cov-2

[0064] All experiments were performed in a BSL-3 facility. A solution of M-1 in isopropanol, with the same composition reported in Example 6 (Bz 1%, Ag 0.002%, PSS 0.62%), was sprayed onto disposable plastic Petri dishes and left to dry in a biosafety cabinet. Then, 1 ml of SARS-Cov-2 (ATCC: VR-740) was incubated in each Petri dish for 5 minutes. After treatment, the virus was used to inoculate human sensitive cells (VeroE6; ATCC? CRL-1586?). Cellular supernatants were collected at 24, 48 and 72 hours post-infection to evaluate viral replication. As a positive control a untreated viral inoculum was used. The replication of SARS-Cov-2 was estimated by qRT-PCR after extraction of RNA. The cytopathic effect in the infected cells was assessed by optical microscopy (Nikon inverted microscope).

[0065] Analytical results are expressed as threshold cycles (Ct), namely the cycle in which the target becomes detectable. Average Ct is shown in the graph of FIG. 9, in which nt stands for non-treated (i.e. control) and M-1 stands for treated with M-1.

[0066] Table 3 below shows the replication of SARS-Cov-2 in VeroE6 cells after treatment with M-1, replication which is expressed as logarithmic difference compared to the untreated control. The pre-treatment of SARS-Cov-2 with M-1 cause a reduction of 2,665 logarithms of the viral charge at 24 hours post-infection (hpi), a reducation of 3,696 logarithms at 48 hours hpi and a reduction of 6,832 logarithms at 72 hpi compared to the untreated incolumum:

TABLE-US-00003 TABLE 3 Samples ?Ct Logarithmic difference M-1 24 hpi 8.855 ?2.665 M-1 48 hpi 12.278 ?3.696 M-1 72 hpi 22.7095 ?6.832

[0067] The graph of FIG. 10 represent the difference in viral replication after treatment with M-1. The morphological analysis indicated that the cells infected with the virus treated with M-1 showed a lower cytopathic effect compared to the ones infected with untreated virus. This evidence occurred at all times points of post-infection observation (24, 48 and 72 hours post-infection). In conclusion, the incubation of SARS-Cov-2 for 5 minutes on surfaces treated with M-1 is able to reduce the viral charge. The reduction varies from 460 to 6 million times difference. The molecular data is supported by the morphological analysis of infected cells, showing that the cytopathic effect lowered during invention with the virus treated with M-1 compared to the untreated virus.

EXAMPLE 10

Evaluation of the Antiviral Effectiveness of M-2 Towards SARS-Cov2

[0068] All experiments were performed in a BSL-3 facility. A solution of M-2 in isopropanol, with the same composition reported in Example 6 (Bz 1%, PSS 0.62%), was sprayed onto disposable plastic Petri dishes and left to dry in a biosafety cabinet. Then, 1 ml of SARS-Cov-2 inoculum was incubated in each Petri dish for 5 minutes. After treatment, the virus was used to inoculate human sensitive cells (VeroE6; ATCC? CRL-1586?). Cellular supernatants were collected at 24, 48 and 72 hours post-infection to evaluate viral replication. As a positive control a untreated viral inoculum was used. The replication of SARS-Cov-2 was estimated by qRT-PCR after extraction of RNA. The cytopathic effect in the infected cells was assessed by optical microscopy (Nikon inverted microscope).

[0069] Analytical results are expressed as threshold cycles (Ct), namely the cycle in which the target becomes detectable. The threshold cycles are shown in the graph of FIG. 11, in which NT stands for non-treated (i.e. control) and M-2 stands for treated with M-2.

[0070] Table 4 below shows the replication of SARS-Cov-2 in VeroE6 cells after treatment with M-2, replication which is expressed as logarithmic difference compared to the untreated control. The pre-treatment of SARS-Cov-2 with M-2 caused a significant reduction of the viral charge at all time points post-infection (hours post-infection: hpi) compared to the untreated virus, with an average reduction of more than 5 logarithms, corresponding to a decrease of over 10.sup.5:

TABLE-US-00004 TABLE 4 Samples ?Ct Logarithmic difference M-2 24 hpi 17.37 ?5.23 M-2 48 hpi 18.56 ?5.59 M-2 72 hpi 16.64 ?5.01

[0071] The graph of FIG. 12 represent the difference in viral replication after treatment with M-2. The morphological analysis indicated that the cells infected with the virus treated with M-2 showed a lower cytopathic effect compared to the ones infected with untreated virus. This evidence occurred at 72 hours post-infection. In conclusion, incubation of SARS-Cov-2 for 5 minutes on surfaces treated with M-2 led to a reduction of the viral charge at 24, 48 and 72 hours post-infection. The reduction is more than 5 logarithms. This decrease of the viral charge is responsible for a reduction of the cytopathic effect, as evidenced by morphological observation at 72 hours post-infection compared to cells infected with untreated virus.

[0072] Variation and/or additions of what has been described above are possible.

[0073] Even if the polymeric composition according to the invention were prepared mainly on a laboratory scale, the skilled person will be able to appropriately adapt said polymeric compositions to produce them on industrial scale.

[0074] In particular, the skilled person will be able to suitably incorporated the polymeric compositions according to the invention into coatings intended for frequently touched objects, as well as medical equipment, face protective masks and air decontamination/air conditioning devices. Similarly, the skilled person will be able to suitably include the polymeric compositions according to the invention in formulations of personal care products, such as hand sanitizer gels.