Bioactive, ruthenium-containing coating and device

The present invention relates to a biologically active coating which comprises at least ruthenium or a silver-ruthenium bimetal particle and which is applied to a silver surface or containing silver or which is in contact with a silver coating and a method for coating the device and applying a biologically active coating.

[0002] As early as 1869, Ravelin and in 1893 Nagela described the antibacterial effect of silver at very low doses. At present, the effectiveness of silver is still of great importance (Landau,

U. (2006): Die keimreduzierende Wirkung des Silbers in Hygiene, Medizin und Wasseraufbereitung: Die Oligodynamie des Silbers; Isensee-Verlag, Oldenburg, 2006-10-03). [0003] Microbial contaminants also cause significant problems and losses in trade in all areas that are related to water quality, aqueous solutions and hygiene. Such areas concern, for example, hospitals, hygiene institutes, food technology, production, air conditioning as well as households.

[0004] Therefore, for a long time there have been various antimicrobial disinfectant solutions containing corrosive antimicrobial chemicals such as, for example, formaldehyde, alcohols, phenols, sodium azide, sodium hypochlorite or strong oxidizing agents, e.g. hypochlorite, bleaching agent or mineral acid.

[0005] The disadvantages of these solutions and methods are that the highly corrosive chemicals and oxidizing agents used for decontamination and disinfection have a high corrosion and toxic potential. As a result, treated water and aqueous solutions are usually unsuitable for human consumption and the equipment or surfaces used can be damaged by corrosion.

[0006] Therefore, usually such caustic chemical solutions for cleaning and rinsing devices, instruments and work surfaces are used in closed circuits.

[0007] The use of silver technology has caused a gradual reduction of this problem. The oligodynamic effect of silver makes it possible to sterilize water or aqueous solutions to obtain a quality that is safe for humans and protects materials and surfaces. Thus, silver technology is also used for drinking water for its production, treatment and quality assurance.

[0008] Thus, work is continuing to improve the efficiency of silver technology. From WO 2005/023206 A2 and DE 10054248 A1, for example, newer methods are known which use the properties of nanoparticles to obtain an accelerated release of silver ions on a very large surface.

[0009] From WO 01/143788 A2 a device is known which has been coated with a polymer comprising a colloid. The colloid is formed in this case by the reaction of the first salt, which may be a salt of silver and / or ruthenium, with a second salt, which may be ascorbate. WO 01/143788 A2 further discloses a method of producing a colloidal polymer coating that includes silver, ruthenium and ascorbate, wherein the ascorbate serves together with silver and / or ruthenium salts to form a colloid, which leads to increased antimicrobial intake capacity and changes kinetics of the release of oligodynamic ions.

[0010] The commercial importance of materials and methods for maintaining water quality or generally the quality of aqueous solutions for humans due to the silver technology is already emphasized by the high availability in trade of relevant products under various trade names.

[0011] Disadvantages of the known methods associated with silver technology are the much delayed occurrence of action after contacting silver with water and only selective antibacterial activity. Thus, it usually takes many hours, often even substantially longer, until sufficient silver ions are released from the surface, after contact of silver with contaminated water, to obtain a sufficient level of microbial destruction and water sterilization.

[0012] The problems exhibited by silver technology relate to two areas: 1. The temporarily delayed occurrence of the action of destroying germs and 2. A limited spectrum of action with respect to effective disinfection and disinfection of water or aqueous solutions to destroy or remove microbes and problematic biomolecules. Thus, improved methods and methods are still being sought to increase the efficiency of silver technology.

[0013] New discoveries of modern molecular biology and genetic engineering also indicate that genetic information, single genes or even parts and specific proteins are sufficient to cause disease or cause undesirable genetic changes in addition to microbes (Elhafi et al., 2004 ). Therefore, effective disinfection of the surface to destroy or remove active biomolecules would provide additional safety enhancement in all areas related to water quality and hygiene.

[0014] Thus, in practice, there is a need for improved materials, methods and methods for effective and above all also non-toxic and non-corrosive complete decontamination and disinfection of water or aqueous solutions to destroy or remove microbes and active biomolecules, such as DNA, RNA and others. protein.

Summary of the invention [0015] It is therefore an object of the present invention to overcome the disadvantages of the prior art and to develop new materials and methods that provide improved and enhanced performance of silver technology.

[0016] According to the invention, this object is achieved in that the coating further comprises at least one vitamin or at least one vitamin derivative and at least one surfactant, wherein the vitamin is ascorbic acid.

[0017] Ruthenium particles on the silver surface or in direct contact with silver particles serve in this case to accelerate the release of silver ions, while being also "anchoring sites" for binding and complexing ascorbic acid molecules or its derivatives.

[0018] Furthermore, the object is achieved by the method of coating the device, namely by applying a ruthenium coating to the silver surface or a silver-containing device, or applying a silver coating to the device and then applying the ruthenium coating to the silver coating, or contacting the silver coating and the ruthenium coating, or applying ruthenium-silver particles to the device; and applying to the surface comprising silver and ruthenium devices at least one vitamin or at least one derivative of the vitamin and at least one surfactant, wherein the vitamin is ascorbic acid.

[0019] In the present invention, the commonly known oligodynamic effect of silver leading to a reduction in the amount of germs is significantly increased and strengthened by the combination of silver with ruthenium and ascorbic acid or its derivatives and a surface active substance. These new biologically active metal surfaces lead to faster and more effective destruction of microorganisms. At the same time, these new metal surfaces prevent colonization by microorganisms and the sticking or permanent deposition of biomolecules, such as DNA, RNA or proteins. In this way, self-cleaning surfaces are obtained, which when contacted with water or aqueous solutions very quickly and effectively obtain a germ-free state for a long time.

[0020] According to the invention, the silver or silver surface used may be the surface of a suitable dense or solid material.

This surface may, however, also substantially comprise any other material (such as e.g. plastic, ceramic, glass, etc.) with a thin silver coating applied which, together with the applied ruthenium coating, forms an effective ruthenium-silver layering with the backsheet or substrate. of silver or silver alloy and with moisture and humidity permeable outer layer, top layer or top layer of ruthenium.

[0021] Coatings or coating systems, i.e. a ruthenium coating and optionally a required silver bottom layer (typically a thickness of 2-10 gm), are preferably applied or deposited in an electroplated manner. Suitable coating methods in this case are also other coating methods, such as PVD, CVD, sputtering, sol, gel and reduction methods.

[0022] The application of the ruthenium coatings is regulated in this case in such a way that the silver-containing surface is in contact with the environment to transmit moisture or it may come in contact with the environment to transmit moisture through through, preferably finely formed, free surfaces, openings, pores. , slits, voids, and the like in the ruthenium coating, thereby providing contact allowing the transmission of moisture between the silver and the ruthenium. In case the ruthenium clusters are on the silver surface, the oligodynamic action of the silver can be enhanced in a beneficial manner. Preferably, the ruthenium layers forming clusters, porous or with microcracks, in combination with silver allow a very efficient release of silver ions into the environment.

[0023] However, it is also possible to use Ag-Ru particles in which silver and ruthenium are in contact enabling electrical conduction and moisture or water wet both metals. The particle size of the silver-ruthenium bimetal may be in the range of microlubes of nanometers, preferably in the range of nanometers and be about <50 nm. Silver and ruthenium particles can also act as single particles when there is close contact between metals in both types of particles.

[0024] Metal particles in the nano- and micrometer range can, for example, be produced by milling, electrochemical, by chemical means by reduction, capillary electrophoresis, hydrothermal synthesis, PVD, CVD or sol-gel. Nanoparticles from ruthenium-silver (Wu et al., 1990 II), platinum-ruthenium (Schmidt et al., 1998), copper-ruthenium (Wu et al., 1990 I) and gold-ruthenium ( Wu et al., 1990 II) according to the prior art is preferably prepared for catalytic purposes.

[0025] Galvanic deposition, in particular the deposition of the ruthenium layers according to the invention, preferably clustered, porous or micro-grooved, can be suitably adjusted by selecting appropriate electrolytes, metal content in the electrolytes, electrolyte temperature, pH of the electrolyte, duration of deposition or duration processing and / or density of current or amount of current. Thus, in particular, the selected galvanic deposition conditions also define the structure and dimensions of the ruthenium (micro) pore and micro-clusters of the invention in the ruthenium layer such that the thickness and structure of the ruthenium layer can be adjusted or shaped as required and in each case optimally adapted. for the purpose of use.

[0026] Before coating, the surfaces are first preferably cleaned and subjected to a pickling and / or rinsing. In the case of a device that does not conduct electricity, the surface of the device must be pre-treated according to methods known in galvanic to provide a peel-resistant coating with silver and ruthenium before applying the silver and ruthenium film.

The first indication regarding the particularly synergistic interaction of ruthenium and ascorbic acid provides the finding that ruthenium can be used very effectively in new decontamination solutions with vitamin derivatives, metal ions and detergents.

[0028] New solutions and methods with divalent or trivalent metal ions, vitamin derivatives and detergents have been developed that overcome the disadvantages of the universal disinfectant and disinfectant solutions of the prior art and do not act by means of corrosive corrosive chemicals or strong oxidizing agents, and completely disinfect treated media at room temperature or at slightly elevated temperatures.

[0029] It is known that physiological amounts of micromolar concentrations of antioxidants in combination with divalent metal ions may sporadically lead to damage and partial thread interruptions in nucleic acid molecules (Padayatty et al., 2003; Blokhina et al., 2003; Veal et al. 1991). However, these are only occasional, isolated events that apply only in certain individual cases.

[0030] Systematic testing of new combinations of metal ions, derivatives of vitamins and detergents led to the development of very effective, universal, new disinfection and disinfection solutions. Further new studies confirm that ruthenium also shows a very effective synergistic effect in this system (see Figure 1).

[0031] Surprisingly, however, it was further found later that incubation of the newly treated metal surfaces coated with silver and ruthenium in solutions of ascorbic acid leads to spontaneous binding and complexation of ascorbic acid molecules with ruthenium molecules. In this way, a durable deposit of ascorbic acid molecules forms on the metal surface. An adherent silver and ruthenium coating is also possible as long as there is contact between the metals. A porous silver layer with microcracks on the porous ruthenium layer may also be contemplated if there is contact between the two metals via the aqueous solution. These newly developed coating systems of silver, ruthenium, ascorbic acid and neutral surfactants have completely new unexpected properties.

[0032] The new properties of these metal surfaces lead to the destruction of microorganisms in a much faster and more efficient way than is possible compared to the prior art with the use of existing materials and methods.

[0033] The efficiency of destroying germs is evident from the comparison of various silver samples with silver / ruthenium coatings after treatment with ascorbic acid.

[0034] On round silver plates with a diameter of 1.3 cm, suitable microporous coatings were applied electroplated and then incubated 24 hours in 0.5 M aqueous ascorbic acid solution. After incubation, the plaque was washed twice with sterile water. Thus treated with ascorbic acid silver / ruthenium plaque (Ag / Ru) shows much faster destruction of germs than comparative samples. In the culture under study, the number of germs was significantly reduced after 2 to 20 minutes or the germs were even completely destroyed (see Figure 2A to 2D). After treatment with ascorbic acid, different comparative samples with a pure silver plate (Ag), silver plate with gold coating (Ag / Au) or silver plate with a coating of palladium and nickel (Ag / Pd / Ni) after the contact time and the action of approx. .

[0035] Multiple washing with sterile water of the silver-ruthenium surface treated with ascorbic acid does not cause any significant reduction of the increased antibacterial effect (see Figures 3A to 3D). This shows that the molecules of ascorbic acid on the surface of silver and ruthenium are permanently bound and create a deposit. In addition, a particularly synergistic effect of all three components was found.

[0036] If desired, the ascorbic acid deposit can be refilled by simple application or even by simply rubbing with an aqueous solution of ascorbic acid. Alternatively, the deposit can also be replenished by re-incubating in an ascorbic acid solution.

[0037] Supplementing the ascorbic acid deposit by applying a thin layer of ascorbic acid and detergents provides a particular additional effect that, from now on, the nucleic acid molecules in contact with this surface undergo rapid and complete degradation. A decisive new feature of permanent deposit formation is the preferred, ruthenium-based layers of porous or micro-porous aggregates that support efficient deposit formation.

[0038] A disadvantage of the prior art silver technology, but also generally with respect to most biologically active surfaces is the lack of action in the form of breaking down problematic biomolecules, such as DNA, RNA or proteins. Separate studies show that different surfaces of plastics or metals show no action in the form of breaking down DNA molecules or only very limited (see figure 4). [0039] Particularly synergistic action of the new Ag / Ru coatings in combination with ascorbic acid and detergents is found in studies on the durability of DNA molecules on such coated surfaces. Where DNA samples defined as impurity are applied to these surfaces, analysis using agarose gel by electrophoresis shows fast, complete distribution within 30 minutes to 24 hours. Further analysis using the highly sensitive PCR technology shows that the deposited DNA molecules are not detectable after 30 minutes (see Fig. 6). The comparative sample on the plastic surface does not show any DNA degradation during this time. Thus, new biologically active surfaces have a new additional property related to the self-cleaning of surfaces from problematic biomolecules.

[0040] A further object of the present invention is the use of a coating according to the invention for the production and preservation of germ-free water or aqueous solutions to ensure hygiene and water quality.

[0041] Further advantageous embodiments of the present invention arise from the objects of the dependent claims.

[0042] The effective operation of the new metal surfaces is all the more surprising since it has been proven that each individual component does not show comparable effective performance.

[0043] Only the application of at least one vitamin or its derivatives and detergents to metal surfaces or to silver and ruthenium coatings leads to a synergistic effect and to accelerated more effective sterilization of aqueous solutions and to the degradation of problematic biomolecules on these metal surfaces or coatings.

The metal surfaces or coatings produced according to the invention thus contain silver, ruthenium and ascorbic acid or its derivatives and at least one surface-active substance.

Preferably, the vitamin used according to the invention or its salts or acid derivatives are one or more compounds and / or their salts selected from the group of water-soluble vitamins with antioxidant properties, namely vitamin C. It is used in amounts ranging from about 1 mM to 1000 mM relative to the total solution, preferably in amounts of about 10 mM to 100 mM.

[0046] An additional increase in effect is achieved by applying thin layers of ascorbic acid or its derivatives and additional surface-active substances. Surfactants for use according to the invention are anionic, nonionic, amphoteric or cationic neutral surfactants or their respective mixtures or combinations with each other. In particular, alkyl ether sulphates, alkyl and / or arylsulfonates, alkyl sulfates, amphoteric surfactants, betaine, alkylamidoalkylamine, alkyl substituted amino acids, alkyl substituted imino acids, acylated amino acids and combinations of amphoteric surfactants can be used. In principle, all neutral surfactants are suitable. Indifferent means that there is no impact on either the synergistic solution or the result of the experiment. According to the invention, anionic and nonionic surfactants are preferred.

[0047] They are used in amounts ranging from about 0.1 to 10 wt.%, Based on the total solution, preferably in amounts of about 0.2 to 0.5 wt.%.

[0048] Two further and / or trivalent metal ions can additionally be applied to the biologically active surfaces according to the invention. These are the ions of metals from the 4th period and / or from the secondary groups I, II and VIII of the periodic table of elements. They are used in the form of their salts with organic and / or inorganic acids or bases. Preferred according to the invention are one or more compounds selected from the side group VIII, in particular iron, cobalt, nickel, copper or zinc.

[0049] They are used in amounts ranging from about 1 mM to 100 mM, relative to the total solution, preferably in amounts of about 5 mM to 10 mM.

[0050] Further suitable inert adjuvants and additives may be applied to the biologically active surfaces according to the invention, such as, for example, suitable buffer substances for adjusting certain pH values, such as Tris (tris (hydroxymethyl) aminomethane), MES (acid 2- ( morpholino) ethanesulfonic), HEPES (2- [4- (2-hydroxyethyl) -1-piperazinyl] ethanesulfonic acid), MOPS (3- (N-morpholino) propanesulfonic acid), carbonates and succinic acid derivatives. These buffer substances are used in amounts ranging from about 1 mM to 500 mM relative to the total solution.

[0051] Contact time and operation between the biologically active metal surfaces of the invention and water or aqueous solutions of about 5 to 20 minutes at room temperature or slightly elevated temperature is generally sufficient for complete decontamination and disinfection. However, the method used can vary and can be adapted to different requirements.

[0052] The present invention enables the development of new biologically active surfaces for hygienic applications and for the production of high quality water due to coatings of silver, ruthenium and ascorbic acid or its derivatives and surfactants. Thus, thanks to the silver technology, a new qualitative leap in disinfection and disinfection is obtained, because in this way it is possible to obtain a faster antimicrobial effect combined with long-lasting protection for a long time. At the same time, permanent attachment to the surface of active biomolecules such as DNA, RNA or proteins is prevented.

[0053] The invention is illustrated by means of the following exemplary figures and embodiments.

Brief description of the drawings [0054]

Fig. 1 shows in particular the synergistic effect of ruthenium and ascorbic acid on the example of DNA particle breakdown.

Figs. 2A-D show the increased antimicrobial activity of silver, ruthenium and anirorbic acid coatings of the invention compared to other prior art silver samples.

Figs. 3A-D show the same test as in Figure 2, after which the identical metal sheets of Figure 2 are again washed with sterile water and dried.

Fig. 4 shows the stability analysis of DNA molecules on various surfaces.

Fig. 5 shows the analysis of effective DNA degradation on new metal surfaces with special coatings.

Fig. 6 shows a PCR analysis of DNA samples after different contact times with new coated metal surfaces according to the invention.

Examples and description of various and preferred embodiments of the invention [0055] Fig. 1 shows the particularly synergistic effect of ruthenium and ascorbic acid on the example of DNA particle breakdown. Identical aliquots of DNA plasmids (YEp351) were treated for 2 minutes below with the given solutions to obtain samples 1-7. The DNA samples were then denatured and the single-stranded DNA molecules were separated by gel electrophoresis on an agarose gel (1%). After staining with ethidium bromide, the images shown are obtained. After treatment with sterile water, the control shows intact plasmid DNA. In the case of thread interrupts, the molecular weight of a given DNA molecule decreases. This can be determined on the gel by comparison with the control and the molecular weight marker. In each case 5 μg of DNA in 5 μΐ of sterile Tris buffer (1 mM, pH 8, 0) were treated with 5 μΐ of the solutions given below for samples 1-7 for 2 minutes at room temperature. The samples were then mixed with 5 μΐ of 100 mM Tris (pH 12), the bromophenol blue marker was added and denatured at 95 ° C for 5 minutes. The renatured samples were immediately cooled at 4 ° C and in each case a 1 μg portion of DNA was applied to the gel strip. DNA after gel electrophoresis in a 1% agarose gel was stained with ethidium bromide and photographed.

Data on samples:

[0056] M: DNA ladder marker, 1 kb; K: control: DNA + 5 μl sterile H₂ABOUT; 1: 100 mM ascorbic acid + 10 mM FeCl3; 2: 10 mM ascorbic acid + 1 mM FeCl3; 3: 100 mM ascorbic acid + 10 mM RuCl3; 4: 10 mM ascorbic acid + 1 mM RuCl3; 5: 100 mM ascorbic acid + 10 mM AgNO3; 6: 10 mM benzoic acid; 7: 100mM ascorbic acid Fig. 2A-D shows the increased antimicrobial activity of new coatings of silver, ruthenium and ascorbic acid compared to other silver samples. Metal plaques (1.3 cm in diameter) were incubated in 0.5 M ascorbic acid, then washed with sterile water and dried. After drying the sample was added to 1 ml of sterile water containing 10⁵ bacteria of the standard strain Escherichia coli RRI. The number of living bacteria was determined after 1, 5, 20 and 60 minutes of incubation and was 10⁵ up to 10⁰.

[0058] Samples: 0: only sterile H2O; 1: pure silver plate (Ag); 2: Silver badge with ruthenium (Ag / Ru), 3: Silver and gold foil (Ag / Au), 4: Silver badge with palladium and nickel (Ag / Pd / Ni); 5: 100 mM ascorbic acid, 10 mM FeCl3; 6: 100 mM ascorbic acid, 10 mM RuCl3, (5 + 6 each with 0.3% SDS and 0.2% Tween 20).

[0059] Figs. 3A-D show the same test as in figure 2, after which the identical metal sheets of figure 2 are again washed with sterile water and dried. After drying the sample was again added to 1 ml of sterile water containing 10⁵ bacteria of the standard strain Escherichia coli RRI. The number of living bacteria was determined after 1, 5, 20 and 60 minutes of incubation and was 10⁵ up to 10⁰.

[0060] Samples: 0: only sterile H2O; 1: pure silver plate (Ag); 2: Silver badge with ruthenium (Ag / Ru), 3: Silver and gold foil (Ag / Au), 4: Silver badge with palladium and nickel (Ag / Pd / Ni); 5: 100 mM ascorbic acid, 10 mM FeCl3; 6: 100 mM ascorbic acid, 10 mM RuCl3, (5 + 6 each with 0.3% SDS and 0.2% Tween 20).

[0061] Fig. 4 shows the stability analysis of DNA molecules on various surfaces.

In each case 50 μΐ of the DNA solution (25 μg / μΐ) was instilled onto the surface. In each case 2 μl aliquots were taken after 24 hours and examined in an agarose gel for analysis. DNA after gel electrophoresis in a 1% agarose gel was stained with ethidium bromide and photographed. A sterile plastic material was used as the control surface.

Applying on the gel:

[0062]

K: Control sample from plastic surface M: Marker / ladder 1 kb: DNA sample from Ag after treatment with ascorbic acid: DNA sample from Ag / Au after treatment with ascorbic acid: DNA sample from Ag / Ru after treatment with ascorbic acid: DNA sample from Pd / Ni after treatment with ascorbic acid. Fig. 5 shows the analysis of effective DNA degradation on new metal surfaces with special coatings. A thin layer of ascorbic acid, metal ions and detergents was additionally applied to the Ag / Ru coating. A solution of 100 mM ascorbic acid, 10 mM FeCl3, 0.3% SDS and 0.2% Tween 20 was applied to the surface by brief immersion, filtration and drying. Subsequently, 50 μΐ of the DNA solution (25 μg / μΐ) was instilled onto the surface. In each case 2 μΐ aliquots were taken after predetermined times and the DNA after gel electrophoresis in a 1% agarose gel was stained with ethidium bromide and photographed. A sterile plastic material was used as the control surface.

Applying on the gel:

[0064]

M: Marker / ladder 1 kb

K1: Control sample from plastic surface after 30 minutes K2: Control sample from plastic surface after 1 hour K3: Control sample from plastic surface after 4 hours K4: Control sample from plastic surface after 24 hours Ab1: DNA sample from the coated surface after 30 minutes

Ab2: DNA sample from the coated surface after 1 hour Ab3: DNA sample from the coated surface after 4 hours Ab4: DNA sample from the coated surface after 24 hours [0065] Fig. 6 shows the PCR analysis of DNA samples after different contact times with new coated metal surfaces . A thin layer of ascorbic acid, metal ions and detergents was additionally applied to Ag / Ru coatings. A solution of 100 mM ascorbic acid, 10 mM FeCl3, 0.3% SDS and 0.2% Tween 20 was applied to the surface by brief immersion, filtration and drying. Then, 50 μΐ of the DNA solution (0.1 μg / μΐ) was instilled onto the surface. In each case 2 μΐ aliquots were taken after predetermined times and in each case transferred by pipette to 50 μΐ of the PCR reaction mixture. The PCR reaction mix contains a pair of primers for amplification of the test DNA (yeast scPCP1 gene). The controls (+/-) show whether the PCR reaction was successful. Based on the bands of 780 base pairs (pz) of the test DNA, it appears that there is still an intact DNA molecule for this gene. In the case of complete removal or destruction of the test DNA, no strands of amplified DNA are detected on the gel.

DNA after gel electrophoresis in a 1% agarose gel was stained with ethidium bromide and photographed. A sterile plastic material was used as the control surface.

Applying on the gel:

[0066] +: positive control of PCR reaction with the test DNA -: negative control of PCR without DNA M: Marker / ladder 1 kb

K1: Control sample from plastic surface after 30 minutes K2: Control sample from plastic surface after 1 hour K3: Control sample from plastic surface after 4 hours Ab1: DNA sample from the coated surface after 30 minutes

Ab2: DNA sample from the coated surface after 1 hour Ab3: DNA sample from the coated surface after 4 hours

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