Antimicrobial photoactive nanofiber polymer material

Abstract

To provide an antimicrobial photoactive nanofiber polymer material.SOLUTION: The present invention provides an antimicrobial photoactive nanofiber polymeric material comprising: - A polymeric nanofiber comprising a hydrophobic domain and a hydrophilic domain; at least one photoactive molecule encapsulated in the hydrophobic domain of the polymeric nanofiber, wherein the photoactive molecule is capable of releasing or generating an antimicrobial active upon irradiation with visible light. The materials of the invention can be used in antimicrobial wound dressings, antimicrobial cosmetic masks, self-disinfecting masks or self-disinfecting filters for respiratory, gas or liquid filtration, self-disinfecting fibers and products thereof, self-disinfecting packaging materials or protective agricultural foils.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to antimicrobial, photoactive nanofiber polymeric materials. [Background technology]

[0002] With the increasing incidence of viral and bacterial infections, often caused by resistant strains, and more generally with regard to the global health problem of so-called hospital-acquired infections, research into new methods of sterilizing microorganisms is becoming increasingly important. For this purpose, the photosensitization reaction of singlet oxygen (O2( 1 Δ g The use of special photoactive dyes, so-called photosensitizers, which generate O2( 1 Δ g ) have attracted considerable interest due to their high reactivity and the resulting cytotoxicity. This cytotoxicity is due to the so-called photodynamic inactivation of bacteria, viruses, yeasts, and protozoa. A significant advantage of PDI is that pathogens do not develop resistance to singlet oxygen.

[0003] Singlet oxygen O2( 1 Δ g The photosensitized generation of O2( ) usually occurs in the liquid phase where the photosensitizer is dissolved. However, this does not allow the photosensitizer to be easily separated from the treated material or product after the photoreaction. If the photosensitizer is immobilized on a solid support, it can be easily separated from the reaction product and reused. Furthermore, the larger the surface area of ​​the support, the smaller the amount or concentration of photosensitizer in the support can be to obtain the desired effect. By encapsulating a hydrophobic photosensitizer in polymer nanofibers, the photogenerated O2( 1 Δ g The specific properties of O2( (oxidizing, cytotoxic, "in situ" activity) are combined with the specific properties of nanofiber membranes containing suitable polymers (transparency to light, easy oxygen diffusion, large specific surface area). The highly nanoporous structure of nanofiber membranes allows for efficient capture of bacteria, viruses and other pathogens.1 Δ g ) diffusion paths are on the order of a few hundred nanometers at most.

[0004] Previous research has shown that nanofiber polymer membranes containing photosensitizers can be prepared using the electrospinning method. The membranes have a thickness of approximately 0.03 mm and an area weight of approximately 2 g / m. 2 These membranes, with average nanofiber diameters in the range of 100-400 nm and containing photosensitizers, were characterized by UV-VIS, fluorescence, and time-resolved spectroscopy (Mosinger, J., Jirsak, O., Kubat, P., Lang, K., Mosinger Jr., B. Bactericidal nanofabrics based on photoproduction of singlet oxygen Journal of Materials Chemistry, 2007, vol. 17 (2), pp. 164-166).

[0005] Many parameters can affect the properties, effects, and undesired quenching of a material. There remains a need to identify and provide suitable parameters that will enable the provision of cost-effective, useful materials with minimal or no undesired effects or properties for efficient use in a variety of practical applications.

[0006] For applications requiring disinfection of a larger membrane environment, photogeneration of singlet oxygen and other antimicrobial agents, such as NO or I3, may be considered. - The first experiments on these combinations are described in Dolansky, J., Henke, P., Kubat, P., Fraix, A., Sortino, S., Mosinger, J. Polystyrene Nanofiber Materials for Visible-Light-Driven Dual Antibacterial Action via Simultaneous Photogeneration of NO and O2( 1Δ g ) ACS Applied Materials and Interfaces, 2015, vol. 7 (41), pp. 22980-22989; Plistil, L. Henke, P., Kubat, P., Mosinger, J. Anion exchange nanofiber materials activated by daylight with a dual antibacterial effect Photochemical and Photobiological Sciences, 2014, vol. 13 (9), pp. 1321-1329.

[0007] However, such a combination only increases the number of problems facing the practical application of such technology.

[0008] Existing photoactive polymer materials (see CZ303243B6) are suboptimal, particularly because they require relatively long exposure times to excite sufficient antimicrobial activity, which can prevent or significantly limit the practical use of these materials. Summary of the Invention

[0009] The inventors have defined the requirements for practically applicable photoactive nanofiber polymer materials. The requirements are quite broad and often contradictory. Basic requirements imposed on the individual components from which the material is made include, but are not limited to: the polymer should have high oxygen permeability, and the nanofibers formed by the polymer should have small diameters. The polymer should be transparent to light and nonpolar, but its surface should be wettable. The polymer composition should not adversely affect the photophysical properties of the photosensitizer, particularly with respect to quenching the triplet state of the photosensitizer and / or singlet oxygen. The encapsulated photosensitizer should be hydrophobic, have a high quantum yield of singlet oxygen production, and be photostable in the polymer environment, while the solvent must dissolve the photosensitizer simultaneously with the polymer without agglomerating or undergoing chemical modification. Finally, the final material formed from these components by the spinning process should be capable of efficiently capturing pathogens, be homogeneous, and have good mechanical properties. Setting all these parameters so that the resulting material optimally meets all requirements is a very complex and demanding multidimensional problem.

[0010] The objective of the present invention is to provide a solution to this complex problem and thus achieve high antibacterial efficacy, i.e., to provide a photoactive polymer nanofiber material suitable for practical application, capable of being produced in a cost-effective manner, and meeting all safety and efficacy requirements. An important prerequisite for antibacterial efficacy is high singlet oxygen production (and / or nitric oxide radical production), which depends, inter alia, on the light irradiation / exposure dose. However, the same light irradiation resulting in the same singlet oxygen production (and / or nitric oxide radical production) does not necessarily result in the same antibacterial activity. A shorter light dose incident on the surface of the photoactive material will produce the same amount of singlet oxygen as a longer light dose incident on the surface of the photoactive material, but the shorter light dose will produce higher antibacterial activity. Therefore, in order to reach the critical threshold concentration of the antibacterial active agent for a bactericidal or virucidal effect, one of the requirements for enabling the practical application of photoactive antibacterial materials is a high efficiency or yield of the singlet oxygen photogeneration process. The present invention provides a material with these necessary properties.

[0011] The present invention provides an antimicrobial, photoactive nanofiber polymer material comprising: -polymer nanofibers containing hydrophobic and hydrophilic domains; - at least one photoactive molecule encapsulated in the hydrophobic domains of the polymer nanofiber, the photoactive molecule being capable of releasing or generating an antimicrobial active substance after irradiation with visible light.

[0012] The polymer nanofibers include: at least one hydrophilic polymer chosen from poly(ethylene oxide) (PEO), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), cellulose esters and / or ethers such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), cellulose acetate (CAc), chitosan, modified chitosans such as quaternized chitosan, N-alkylchitosan, carboxyalkylchitosan, acylchitosan, thiolated, sulfated and / or phosphorylated chitosan, polyacrylamide, polyacrylic acid, poly(N-isopropylacrylamide) (PNIPAA), and / or at least one hydrophobic polymer selected from polyvinyl butyral (PVB), polyvinylidene fluoride (PVDF), polystyrene (PS), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(vinylidene fluoride-co-trifluoroethylene), poly(chlorotrifluoroethylene-co-vinylidene fluoride), polydimethylsiloxane (PDMS), polycaprolactone (PCL), polypropylene (PP), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), polycarbonate, polyamide 6, and / or at least one copolymer having hydrophilic and hydrophobic domains chosen from poly(ε-caprolactone), copolymers of poly(ethylene oxide) / poly(ε-caprolactone) copolymers (PEO-PCL), polyurethanes comprising hexamethylene diisocyanate and poly(ethylene oxide) in combination with at least one hydrophilic polymer or with at least one hydrophobic polymer, in combination with 1,4-butanediol as chain extender, and polyurethanes comprising linear polycarbonate diol, isophorone diisocyanate and isophorone diamine, or - a polyurethane having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide), the polyurethane having a ratio (w / w) between the poly(ethylene oxide) domains and the rest of the polymer chain of between 3 and 8, or - Polyurethane containing linear polycarbonate diol, isophorone diisocyanate and isophorone diamine.

[0013] The encapsulated photoactive molecule can be selected from at least one singlet oxygen-producing photosensitizer, at least one nitric oxide (NO) radical photodonor, and combinations thereof. In the case of a singlet oxygen-producing photosensitizer, the antimicrobial active substance generated and / or released is a singlet oxygen molecule. In the case of an NO radical photodonor, the antimicrobial active substance generated and / or released is a nitric oxide radical.

[0014] In some embodiments, the material comprising at least one singlet oxygen-producing photosensitizer further comprises iodide in the form of an inorganic iodide or an organic iodide. The presence of iodide enhances the I3 mediated photo-generated singlet oxygen by the photosensitizer. - Iodide is another potent antimicrobial agent with a long diffusion length, I3 - / I2 acts as an indirect photodonor.

[0015] As used herein, the term "nanofiber" or "nanofibers," unless otherwise indicated by the immediate context, refers to fibers having a diameter in the range of 10 to 950 nm, preferably 50 to 500 nm, and more preferably 100 to 350 nm. Generally, nanofibers can be produced by various methods, such as electrospinning, centrifugal spinning, drawing, thermally induced phase separation, and template synthesis. Electrospinning and / or centrifugal spinning are preferred methods for producing nanofibers in the present invention.

[0016] Generally, nanofibers may preferably be produced from polymers having a number average molecular weight (Mn) in the range of 20,000 to 100,000, preferably in the range of 30,000 to 900,000, and more preferably in the range of 40,000 to 700,000.

[0017] The terms "hydrophilic domain" and "hydrophobic domain" refer to portions of a polymer chain that have hydrophilic or hydrophobic properties, respectively. Each domain is at least 10 atoms long and is contained in a linear polymer chain. The hydrophilic and hydrophobic domains of a nanofiber are formed by the hydrophilic and hydrophobic domains of individual polymer chains, by blending hydrophilic and hydrophobic polymers, or by blending hydrophilic or hydrophobic polymers with polymers that have both hydrophobic and hydrophilic domains.

[0018] The term "polymer" includes homopolymers as well as copolymers, including, for example, block copolymers, alternating copolymers, and random copolymers.

[0019] Polymer nanofibers can be formed from one polymer or multiple polymers. When polymer nanofibers are formed from one polymer, the polymer contains both hydrophilic and hydrophobic domains in its chain (typically a copolymer). When polymer nanofibers are formed from multiple polymers, the polymers can be hydrophilic polymers (including hydrophilic homopolymers and hydrophilic copolymers), hydrophobic polymers (including hydrophobic homopolymers and hydrophobic copolymers), or polymers that contain both hydrophilic and hydrophobic domains in their chain.

[0020] The hydrophobic and hydrophilic domains of the nanofibers may be formed by domains of a single polymer. Such a polymer may be a copolymer having both hydrophilic and hydrophobic domains. Such copolymers preferably include polyurethanes combining hydrophobic and hydrophilic domains, or copolymers of caprolactone and hydrophilic monomers. More preferably, such polymers include poly(ethylene oxide) / poly(ε-caprolactone) copolymer (PEO-PCL), polyurethanes containing hexamethylene diisocyanate and poly(ethylene oxide) combined with 1,4-butanediol as a chain extender, and polyurethanes containing linear polycarbonate diol, isophorone diisocyanate, and isophorone diamine.

[0021] The hydrophobic and hydrophilic domains of the nanofibers can also be formed by at least one hydrophilic polymer and at least one hydrophobic polymer that are combined (e.g., mixed) and subjected to a process to form the nanofibers, such as electrospinning.

[0022] Suitable hydrophilic polymers include poly(ethylene oxide) (PEO), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), cellulose esters and / or ethers such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), cellulose acetate (CAc), chitosan, modified chitosans such as quaternized chitosan, N-alkylchitosan, carboxyalkylchitosan, acylchitosan, thiolated, sulfated, and / or phosphorylated chitosan, polyacrylamide, polyacrylic acid, poly(N-isopropylacrylamide) (PNIPAA). More preferably, the hydrophilic polymer may be selected from the group consisting of poly(ethylene oxide), cellulose acetate, hydroxypropylmethylcellulose, hydroxypropylcellulose, and polyacrylic acid.

[0023] Suitable hydrophobic polymers are polyvinyl butyral (PVB), polyvinylidene fluoride (PVDF), polystyrene (PS), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(vinylidene fluoride-co-trifluoroethylene), poly(chlorotrifluoroethylene-co-vinylidene fluoride), polydimethylsiloxane (PDMS), polycaprolactone (PCL), polypropylene (PP), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), polycarbonate, and polyamide 6. More preferred are polyvinylidene fluoride, poly(vinylidene fluoride-co-hexafluoropropylene), polydimethylsiloxane, polycaprolactone, and polystyrene.

[0024] Preferably, the combination of hydrophilic and hydrophobic polymers is a combination of poly(ethylene oxide) and / or cellulose acetate from the group of hydrophilic polymers with one or more hydrophobic polymers selected from polyvinylidene fluoride, polystyrene, poly(vinylidene fluoride-co-hexafluoropropylene) or polycaprolactone.

[0025] In some embodiments, the nanofibers may comprise at least one copolymer having hydrophilic and hydrophobic domains in combination with at least one hydrophilic polymer and / or at least one hydrophobic polymer. Polyvinylidene fluoride copolymers may be combined with polyurethanes and / or copolymers of poly(ε-caprolactone). More specifically, poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride-co-trifluoroethylene), and / or poly(chlorotrifluoroethylene-co-vinylidene fluoride) may be combined with PEO / PCL copolymers and / or polyurethanes, such as polyurethanes having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol, and poly(ethylene oxide), or polyurethanes having monomer units derived from linear polycarbonate diol, isophorone diisocyanate, and isophorone diamine.

[0026] Polyurethanes having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol, and poly(ethylene oxide) preferably have a ratio (w / w) of poly(ethylene oxide) domains to the rest of the polymer chain of from 3 to 8, more preferably from 3.3 to 7.8.

[0027] The provision of hydrophilic and hydrophobic domains enhances the interaction between the nanofibers (especially their hydrophobic domains) and the encapsulated photosensitizers and / or NO radical photodonors. This reduces unwanted washout of the encapsulated materials and prevents aggregation of the photoactive molecules, which can result in reduced photoactivity and, ultimately, reduced antibacterial activity. The presence of hydrophilic domains helps achieve dynamic surface wettability and, therefore, better contact between the nanofibers and the target microorganisms. Therefore, combining hydrophilic and hydrophobic properties improves the overall antibacterial activity of the material. Furthermore, mechanical properties may also be improved.

[0028] In a preferred embodiment, the nanofibrous material has at least 60% translucency to visible light (more specifically, at least one wavelength in the range of 400 nm to 900 nm). In particular, the material has at least 60% translucency in the visible region of the significant absorption band of the selected photosensitizer and / or NO photodonor encapsulated in the polymer nanofiber. Translucency is typically determined based on transmittance measurements in the visible region using a standard two-beam UV-vis spectrometer on a 0.03 mm thick polymer nanofilm sample in a cuvette filled with distilled water, with the same solution in a second cuvette used as a reference.

[0029] In this patent application, the term "visible light" refers to electromagnetic radiation within the visible and near-infrared radiation spectrum, i.e., having wavelengths from 400 nm to 900 nm.

[0030] The appropriate ratio between hydrophilic and hydrophobic domains depends on the properties of a particular polymer, particularly its degree of hydrophobicity. Generally, in this patent application, a polymer domain or polymer is considered hydrophilic if the contact angle measured on a nanofiber layer made from it is less than 5 degrees; a polymer domain or polymer is considered highly hydrophobic if the contact angle measured on a nanofiber layer made from it is greater than 100 degrees; and slightly hydrophobic if the contact angle is between 5 and 100 degrees. That is, a hydrophobic polymer is a polymer that has a contact angle of 5 degrees or greater measured on a nanofiber layer made from it. In the simple case of nanofibers comprising hydrophilic and hydrophobic polymers, the preferred ratio between the hydrophilic and hydrophobic polymers may range from 9:1 (w / w) to 1:20 (w / w). In the case of block copolymers, the preferred ratio between the hydrophilic and hydrophobic domains of the block copolymer is also in the range of 9:1 (w / w) to 1:20 (w / w). However, for other copolymers that combine hydrophilic and hydrophobic domains in a single polymer chain, the optimal ratio between hydrophilic and hydrophobic domains depends on the individual polymer. The contact angle of nanofibers composed of hydrophobic or hydrophilic domains alone cannot be determined experimentally and can only be roughly estimated. In this case, the resulting nanofiber surface is preferably hydrophilic (contact angle less than 5°), while the polymer chain preferably contains both hydrophilic and hydrophobic domains. Similarly, for more complex combinations of polymers and copolymers (e.g., copolymers with both types of domains combined with hydrophilic or hydrophobic polymers or copolymers), the optimal ratio between hydrophilic and / or polymer and hydrophobic domains and / or polymers depends on the individual polymers and copolymers used. In this case, the resulting nanofiber surface is preferably hydrophilic (contact angle less than 5°), while the polymer chain preferably contains both hydrophilic and hydrophobic domains.

[0031] Photosensitizers are generally molecules that can absorb energy from light and use that energy to induce changes in neighboring molecules. The photosensitizer then returns to its ground state and remains chemically intact until it absorbs more energy from light. Singlet oxygen-producing photosensitizers are molecules that convert molecular oxygen into singlet oxygen, O2 ( 1 Δ g The term "photosensitizer" in this patent application is intended to mean "singlet oxygen-producing photosensitizer."

[0032] Singlet oxygen-producing photosensitizers include photoactive compounds such as octahedral inorganic metal clusters, metal nanoparticles, silicon nanocrystals, metal-organic frameworks, semiconductor structures, fullerenes or graphene / carbon, and other types of quantum dots, but preferably organic chromophores and their metal complexes. Organic chromophore-type photosensitizers may be preferably selected from the group consisting of aminoacridine dyes, phenothiazine dyes, phthalocyanine dyes, porphyrinoid dyes (porphyrins and similar macrocyclic compounds), xanthene dyes, and endogenous organic molecules / photosensitizers derived from biological systems such as organisms, tissues, and cells (e.g., hematoporphyrin, chlorophyll, hypericin, and hypocrellin). More specifically, singlet oxygen-producing photosensitizers include free-base tetraphenylporphyrin (TPP), its zinc or magnesium derivatives, zinc or aluminum phthalocyanines (ZnPc or AlPc), acridine orange (AO), toluidine blue (TB, also known as toluidine blue O-TBO), crystal violet (CV), methylene blue (MB), malachite green (MG), rose bengal (RB), hypericin, hypocrellin A, and naphthalocyanines with absorption in the near-infrared region. Even more specifically, free-base tetraphenylporphyrin, its zinc or magnesium derivatives, zinc or aluminum phthalocyanines, acridine orange, toluidine blue, crystal violet, methylene blue, malachite green, hypericin, and naphthalocyanines with absorption in the near-infrared region. These photosensitizers are easily photoactivated by visible light that matches their absorption bands.

[0033] The single oxygen-producing photosensitizer is encapsulated in the polymer nanofibers, typically in the hydrophobic domains.

[0034] Nanofibers can be supplemented with compounds that release long-lived antimicrobial compounds with a longer diffusion length than singlet oxygen upon irradiation with visible light. NO radical photodonors or NO photodonors (both terms are used synonymously herein) that photorelease nitric oxide (NO) fit these requirements. This inorganic free radical has a lifetime of approximately 1–4 s and a diffusion distance of approximately 100 μm in aqueous media, whereas singlet oxygen has a lifetime of approximately 3.5 μs and a diffusion distance of approximately 200 nm in aqueous media. Like singlet oxygen, NO is characterized by its small size, lack of charge, and multi-target therapeutic potential with a broad spectrum of antimicrobial activity that also limits bacterial biofilm formation. Furthermore, NO has vasodilatory properties and is known as an endogenous inflammation regulator. Its use in promoting wound healing and in cosmetics is motivated by its role as an endogenous regulator. Preferably, photogeneration of NO triggered exclusively by visible light can be achieved by encapsulating nonpolar NO photodonors in polymer nanofibers. Alternatively, the NO photodonor can be incorporated into the polymer nanofibers by graft polymerization, or a charged NO photodonor can be attached to charged groups on the polymer chains by electrostatic interactions.

[0035] The NO radical photodonors encapsulated in polymer nanofibers (typically in their hydrophobic domains) typically include aromatic hydrocarbons bearing nitro or nitroso groups, more specifically nitrobenzene derivatives bearing trifluoromethyl groups at the ortho positions, derivatives of N-nitrosoaminophenol, derivatives of dimethylnitrobenzene, or nitro-substituted polycyclic aromatic hydrocarbons. More specifically, NO photodonors include derivatives of the following: 1-amino-3-(trifluoromethyl)-4-nitrobenzenamine, 4-(N-(aminopropyl)-3-(trifluoromethyl)-4-nitrobenzenamine)-7-nitrobenzofurazan, dimethylnitrobenzene, 4-nitro-3-(trifluoromethyl)aniline, 6-nitrobenzo[a]pyrene, 1-[(2'-nitrophenyl)methoxy]-2-oxo-3,3-diethyl-1-triazene, 2,6-dimethylnitrobenzene, 4-(4,4-difluoro-2,6-diiodo-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacen-8-yl)-N-(3-((4-nitro-3-(trifluoromethyl)phenyl)(nitroso)amino)propyl)butanamide.

[0036] In some embodiments, nanofibers can be electrospun using iodide ions, such as inorganic and organic iodides. In the presence of a photosensitizer that photogenerates singlet oxygen, the iodide ions readily react with singlet oxygen to produce I3, another potent antimicrobial agent with a long diffusion length. - / I2. Iodide contained in the polymer nanofiber matrix forms I3 - / I2 release is O2( 1 Δ g ) is achieved indirectly through photogeneration of I3 - Singlet oxygen acts as an indirect photodonor of I / I. - and the corresponding antibacterial active form, I3 - Easily oxidized to I2. I3 - The indirect photogeneration of / I2 is controlled only by visible light, exposure time, and exposure area.

[0037] Indirect I3 - The singlet oxygen producing photosensitizer that induces I2 photogeneration preferably includes free base tetraphenylporphyrin, its zinc or magnesium derivatives, zinc or aluminum phthalocyanine, acridine orange, toluidine blue, crystal violet, methylene blue, malachite green, hypericin, or a suitable combination thereof. - The / I2 indirect photodonors preferably include organic and inorganic iodide salts, more specifically, alkali metal and alkaline earth metal iodide salts, and quaternary ammonium iodides, more specifically, potassium iodide, sodium iodide, magnesium iodide, calcium iodide, and tetraethylammonium iodide.

[0038] It is particularly advantageous to use several singlet oxygen-producing photosensitizers in combination, in which case the absorption spectra of the individual singlet oxygen-producing photosensitizers only partially overlap, preferably overlap at less than 70% of the wavelengths, more preferably overlap at less than 50% of the wavelengths, even more preferably overlap at less than 30% of the wavelengths, and even more preferably do not overlap.

[0039] It is also particularly advantageous to use a combination of several NO radical photodonors, in which case the absorption spectra of the individual NO radical photodonors only partially overlap, preferably overlap over less than 70% of the wavelengths, more preferably overlap over less than 50% of the wavelengths, even more preferably overlap over less than 30% of the wavelengths, and even more preferably do not overlap.

[0040] The following combinations of two singlet oxygen-producing photosensitizers are considered preferable due to the small overlap of their absorption spectra: TPP&ZnPc, TPP&RB, TPP&MB, TPP&hypericin, TPP&MG, TPP&TBO, TPP&CV, AO&TBO, AO&MB, AO&CV, and AO&MG.

[0041] Singlet oxygen-producing photosensitizer and NO radical photodonor, and optionally I3 - When using a / I2 indirect photodonor combination, it is advantageous if the absorption spectra of the singlet oxygen producing photosensitizer and the NO radical photodonor only partially overlap, preferably overlapping at less than 70% of the wavelengths, more preferably overlapping at less than 50% of the wavelengths, even more preferably overlapping at less than 30% of the wavelengths, and even more preferably not overlapping at all. Based on the small or no overlap in the absorption spectra of the photoactive compounds, the following singlet oxygen-producing photosensitizers, and optionally I3 - Iodide for I / I photogeneration, and NO radical photodonors are preferred: ZnPc, TBO, CV, MB, MG, chlorin, hypericin, and naphthalocyanine; and optionally, I as previously described herein. - / I2 indirect photodonors; and derivatives of 1-amino-3-(trifluoromethyl)-4-nitrobenzenamine, 4-(N-(aminopropyl)-3-(trifluoromethyl)-4-nitrobenzenamine)-7-nitrobenzofurazan, dimethylnitrobenzene, 4-nitro-3-(trifluoromethyl)aniline, or 6-nitrobenzo[a]pyrene.

[0042] In a preferred embodiment, the polymer nanofibers should contain 0.01 to 5 wt% photosensitizer and optionally 0.1 to 10 wt% associated iodide and / or 0.1 to 10 wt% NO photodonor, more preferably 0.05 to 1 wt% photosensitizer and optionally 0.5 to 5 wt% iodide and / or 0.5 to 5 wt% NO photodonor (wt% = -% w / w of polymer weight).

[0043] The term "encapsulated" refers to the state in which molecules of the photoactive agent are incorporated into the hydrophobic domains of the polymer nanofibers through supramolecular interactions, including, for example, weak hydrophobic interactions, van der Waals interactions, π-π interactions, or other supramolecular interactions, but not covalent interactions.

[0044] In some embodiments, the nanofiber material further comprises magnetic or magnetizable particles encapsulated within or adsorbed onto the nanofibers, which may be polyethyleneimine-stabilized maghemite- or magnetite-based microparticles (1-100 micrometers in size) or nanoparticles (5-1000 nanometers in size).

[0045] In some embodiments, the nanofiber material is disposed on a base material or substrate, such as a layer of a base material or substrate. The base material can be a polymeric material. Examples of base materials include a polymeric spunbond microfiber layer, such as polypropylene spunbond, a polymeric foam layer, such as polyurethane foam, adhesive tape, baking paper, silicone paper, plastic wrap, aluminum foil, and other readily available flat materials and / or substrates.

[0046] In a second aspect of the present invention, there is provided a method for producing the material of the present invention, the method comprising the steps of: - providing a solution or dispersion of a mixture of hydrophilic and hydrophobic polymers and / or copolymers having hydrophilic and hydrophobic domains in a suitable solvent or a mixture of suitable solvents; - in a solution or dispersion containing at least one single oxygen-producing photosensitizer and, optionally, at least one I3 - / I2 indirect photodonor and / or at least one NO radical photodonor; - producing nanofibers from a solution or dispersion, preferably on a base material or substrate, preferably by electrospinning or centrifugal spinning; - optionally subjecting the produced nanofibers to a chemical or physical treatment.

[0047] Suitable solvents for dissolving or dispersing mixtures of hydrophilic and hydrophobic polymers and / or copolymers having hydrophilic and hydrophobic domains are preferably selected from dimethylformamide (DMF), tetrahydrofuran (THF), acetic acid, formic acid, ethanol, methanol, chloroform, dimethylacetamide, dimethylsulfonamide (DMSO), acetone, distilled water, dichloromethane, toluene, isopropanol, hydrochloric acid, camphorsulfonic acid, trifluoroacetic acid, carbon disulfide, and cyclohexanone. It is also advantageous to use mixtures of these solvents, such as THF / DMF, chloroform / ethanol, chloroform / methanol, chloroform / ethanol / methanol, dimethylacetamide / acetone, ethanol / DMSO, acetone / DMSO, acetone / DMF, and acetic acid / formic acid.

[0048] The presence of polymer nanofibers containing hydrophobic and hydrophilic domains is crucial for the good antibacterial function of photoactive materials. As previously described, this can be achieved by combining polymers with hydrophobic and hydrophilic domains. However, in principle, the same result can be achieved by electrospinning a hydrophobic polymer with photoactive molecules and then chemically or physically treating the electrospun nanofiber layer. This could include treatment with plasma, polydopamine, surfactants, or sulfonation. While these treatments represent an additional production step aimed at hydrophilizing the nanofibers, especially their surfaces, they have significant drawbacks that prevent the practical use of the photoactive materials obtained in this way. In general, along with the change in hydrophilicity, these procedures alter or even worsen other properties important for good antibacterial function, such as the photoactivity of the encapsulated photoactive molecules, the translucency of the polymer nanofiber, and / or its mechanical properties.

[0049] A third aspect of the present invention is the nanofiber material of the present invention for use as an antibacterial wound dressing, an antibacterial cosmetic facial mask, a self-sterilizing facial mask or respirator, or a self-sterilizing filter for filtering air (more generally, gases) or water (more generally, liquids). The nanofiber material can also be used as a self-sterilizing textile, packaging material, or agricultural protective foil. In all of these applications, the photoactivated antibacterial nanofiber polymer material can be used either as a self-supporting layer or as a separate layer added to materials commonly used for related purposes as described herein above, thereby allowing for easy adaptation to the intended use. [Brief explanation of the drawings]

[0050] [Figure 1] The effect of the hydrophilicity of the polymer matrix on the photoactivity of the materials, measured through the formation of I3- induced by photogenerated singlet oxygen. The change in UV / VIS absorbance at 351 nm (due to the formation of I3- in the iodide detection solution) of different nanofiber materials containing polycaprolactone and polyethylene oxide and 0.1% TPP photosensitizer was recorded at regular time intervals and compared with a blank solution of the same composition stored in the dark. A gradual increase in the ratio of the hydrophilic component (PEO) in the PEO-PCL blend material from pure PCL nanofibers (squares / solid line) through a 9:1 PCL:PEO blend (circles / dashed line), an 8:2 PCL:PEO blend (triangles / dotted line), and a 7:3 PCL:PEO blend (diamonds / dotted and dashed lines) resulted in a significant increase in photoactivity. This indicates that the appropriate ratio of hydrophobic and hydrophilic domains is crucial for the photogeneration of singlet oxygen by photoactive nanomaterials and their subsequent antibacterial function. [Figure 2]The optimal ratio of hydrophilic to hydrophobic domains in polyurethanes results in optimal photoactivity of nanofiber materials, as measured through the change in absorbance at 351 nm due to the formation of I3- induced by photogenerated singlet oxygen in the iodide detection solution. Nanofibers electrospun from polyurethanes with a PEO segment to the remainder of the polymer chain ratio (w / w) of 3.3 (HH3 - squares / solid line) or 7.8 (HH8 - circles / solid line) exhibit high photoactivity (and consequently, high photodynamic inactivation of microorganisms), whereas excessively hydrophilic polyurethanes (PEO segment to the remainder of the polymer chain ratio of 11.8 (HH12 - triangles / dotted line)) result in low photoactivity of nanofibers. When the polyurethane does not contain hydrophilic domains, the photoactivity of nanofibers prepared by a similar method is also significantly reduced (PU - diamonds / dotted and dashed lines). [Figure 3A] The presence of hydrophilic domains is crucial for optimal photoactivity (A) and antibacterial activity (B) of nanofiber materials. Nanofiber membranes electrospun from purely hydrophobic PVDF-HFP (dashed line / striped columns) encapsulating TPP exhibit several-fold lower photoactivity (A) and correspondingly significantly lower photoinduced antibacterial activity (B) than a hydrophobic-hydrophilic mixture of PVDF-HFP and polyurethane with a PEO segment to polymer chain ratio of 7.8 (HH8 - solid line / white columns). Panel A shows the change in absorbance at 351 nm due to the formation of I3- induced by photogenerated singlet oxygen in the iodide detection solution at defined times after irradiating a sample of the material with visible light. Panel B shows the antibacterial activity of the photoactivated material, plotted as colony-forming units (CFUs) relative to the CFU count of a control sample—an equivalent nanofiber material without irradiation. Photoactivity measured spectroscopically and antibacterial activity measured as a reduction in CFU counts are naturally highly correlated. [Figure 3B]The presence of hydrophilic domains is crucial for optimal photoactivity (A) and antibacterial activity (B) of nanofiber materials. Nanofiber membranes electrospun from purely hydrophobic PVDF-HFP (dashed line / striped columns) encapsulating TPP exhibit several-fold lower photoactivity (A) and correspondingly significantly lower photoinduced antibacterial activity (B) than a hydrophobic-hydrophilic mixture of PVDF-HFP and polyurethane with a PEO segment to polymer chain ratio of 7.8 (HH8 - solid line / white columns). Panel A shows the change in absorbance at 351 nm due to the formation of I3- induced by photogenerated singlet oxygen in the iodide detection solution at defined times after irradiating the material sample with visible light. Panel B shows the antibacterial activity of the photoactivated material, plotted as colony-forming unit (CFU) counts relative to the CFU counts of a control sample—an equivalent nanofiber material without irradiation. Photoactivity measured spectroscopically and antibacterial activity measured as a reduction in CFU counts are naturally highly correlated. [Figure 4] Comparing 1% Rose Bengal-loaded PVB / HPC nanofibers (dashed line) with pure hydrophobic nanofibers made of PVB (solid line) under the same experimental conditions reveals that the presence of hydrophilic domains is necessary to significantly enhance the photoactivity of the nanofibers. Individual dots represent the change in absorbance at 351 nm due to the formation of I3 - induced by photogenerated singlet oxygen in the iodide detection solution at defined times after irradiating the material sample with visible light. [Figure 5]When excited with white light, a synergistic effect is observed between the two encapsulated photosensitizers, which have little or no overlap in their excitation spectra. A comparison of three nanofiber materials fabricated by electrospinning a 10% solution of polyvinyl butyral in ethanol with 0.5% RB (circles / dashed lines), 0.1% TPP (triangles / dotted lines), or 0.5% RB and 0.1% TPP (squares / solid lines) demonstrated that TPP and RB cover a wider range of the white light spectrum than the individual photosensitizers, resulting in higher yields of singlet oxygen production under the same light irradiation. Individual dots represent the change in absorbance at 351 nm due to the formation of I3 - induced by photogenerated singlet oxygen in the iodide detection solution at defined times after irradiating the material samples with visible light. [Figure 6] Photorelease of iodine triggered by photogenerated singlet oxygen can further enhance the antibacterial activity of the nanofiber materials. Nanofiber materials electrospun from the same 16% solution of polystyrene and polyurethane with a ratio (w / w) of PEO segments to the rest of the polymer chain of 7.8 (HH8) in the absence of TPP (striped column) and in the presence of 10% potassium iodide (white column) showed significant differences in antibacterial activity, expressed as colony-forming units (CFUs) relative to the number of CFUs of the control sample—an equivalent nanofiber material without irradiation. [Figure 7] Fluorescence emission spectra of the nanofiber material extract demonstrate that the photosensitizer molecules do not leach from the nanofiber material produced by electrospinning. A piece (4 cm²) of nanofiber membrane was shaken at 90 RPM for 12 hours at laboratory temperature in 4 mL of THF (dotted line) or 4 mL of distilled water (solid line). The fluorescence emission spectra of these two samples excited at 420 nm showed high TPP fluorescence in the THF sample (dotted line), due to the complete dissolution of the polymer nanofibers and the encapsulated photosensitizer in this solvent. However, no TPP fluorescence was detected in the water extract of this material (solid line). DETAILED DESCRIPTION OF THE INVENTION

[0051] (Example) Example 1 A 16% solution of polyethylene oxide (PEO) and polycaprolactone (PCL) in a chloroform-ethanol mixture (8:2 w / w) at a ratio of 3:7 (w / w) with TPP (or ZnPc) dissolved at a concentration of 0.001 g of photosensitizer per gram of polymer is electrospun to produce a nanofiber layer deposited on the surface of a base material, e.g., a polypropylene spunbond microfiber layer. The number-average molecular weights of PEO and PCL are 100,000 g / mol and 80,000 g / mol, respectively.

[0052] The same procedure was repeated with PEO:PCL ratios of 2:8 and 1:9 w / w.

[0053] The hydrophilic polymer component (PEO) in PCL / PEO polymer blend nanofibers or PEO-PCL copolymer nanofibers is responsible for introducing partial hydrophilicity into the nanofibers, which allows for more effective photogeneration of singlet oxygen than nanofibers electrospun from hydrophobic pure PCL under the same conditions, resulting in significantly higher antibacterial activity of the mixed / amphiphilic nanofiber membranes.

[0054] Similarly, PEO-PCL copolymer (1:1, Mn = 40,000 g / mol) was dissolved with the same photosensitizer under the same conditions to obtain similar nanofiber layers. This copolymer approach also resulted in improved singlet oxygen photogeneration and antibacterial activity compared to PCL alone.

[0055] Example 2 A 10% solution of polyurethane (Mn = 120,000-180,000 g / mol) in a tetrahydrofuran / dimethylformamide (THF / DMF) mixture (7:3 w / w) with 0.15% TEAB (-% w / w relative to the weight of the polymer) containing TPP dissolved at a concentration of 0.01 g of photosensitizer per gram of polymer was electrospun to produce nanofiber layers deposited on the surface of a base material, such as a polypropylene spunbond microfiber layer. Nanofibers prepared in this manner from polyurethanes with hydrophilic segments consisting of PEO and additional hydrophobic segments consisting of hexamethylene diisocyanate combined with 1,4-butanediol as a chain extender can have different hydrophobic to hydrophilic domain ratios depending on the amount of each segment in the alternating copolymer chain. This example demonstrates that only nanofibers produced from polyurethanes with optimal hydrophobic to hydrophilic domain ratios exhibit sufficiently high photoactivity.

[0056] Nanofibers electrospun from polyurethanes with a PEO domain to the rest of the polymer chain ratio (w / w) of 3.3 (HH3) or 7.8 (HH8) exhibit high photoactivity (and consequently, high photodynamic inactivation of microorganisms), whereas excessively hydrophilic polyurethanes (PEO segment to the rest of the polymer chain ratio of 11.8 (HH12)) result in low photoactivity of nanofibers. When the polyurethane (PU) does not contain hydrophilic domains, the photoactivity of nanofibers prepared by a similar method is also significantly reduced.

[0057] Therefore, by taking into account the hydrophobicity of the photosensitizer and carefully selecting the polymer composition with respect to the balance of hydrophilic and hydrophobic domains, the photogeneration of singlet oxygen can be doubled.

[0058] Example 3 Hydrophilic or hydrophobic properties do not necessarily have to be limited to a single polymer or polymer segment; they can be combined in blends of amphiphilic copolymers with favorable ratios between hydrophilic and hydrophobic moieties, such as polyurethanes in the previous example, with pure hydrophobic polymers, such as polystyrene or PVDF, or with hydrophobic copolymers, such as poly(vinylidene fluoride-co-hexafluoropropylene). These complex combinations allow for improvements in other properties of the polymer nanofiber layer, such as mechanical properties and oxygen permeability. A 16% solution (1:1 w / w) of polystyrene (Mw = 192,000 g / mol) and polyurethane (HH8) (Mn = 120,000-180,000 g / mol), described in Example 2, with a PEO segment to the rest of the polymer chain ratio (w / w) of 7.8, along with 0.5% ZnPc in a THF / DMF mixture (7:3 w / w), was used to electrospin polymer nanofibers that were deposited on the surface of a polypropylene spunbond microfiber layer. Similarly, solutions (1:1 w / w) of PVDF-HFP (Mn = 130,000 g / mol) and this polyurethane, described in Example 2, with a ratio (w / w) between the PEO segments and the rest of the polymer chain of 7.8, as well as 1% TPP or hypericin in a dimethylacetamide / acetone mixture (7:3 w / w), are used for electrospinning polymer nanofibers. The photoproduction of singlet oxygen (and photodynamic inactivation of microorganisms) is higher in composite polymer systems combining hydrophilic and hydrophobic polymers or polymer chain portions than in purely hydrophobic nanofibers fabricated separately and under identical conditions from only hydrophobic polymers, such as polystyrene (Mw = 192,000 g / mol), PVDF (Mw = 156,000 g / mol), or PVDF-HFP (Mn = 130,000 g / mol).

[0059] Example 4 A 20% solution of polyvinyl butyral and hydroxypropyl cellulose (7:3 w / w) in ethanol was electrospun with rose bengal (methylene blue, chlorophyll A, chlorine, or hypericin) at a concentration of 0.01 g of photosensitizer per gram of polymer to produce a nanofiber layer deposited on the surface of a polypropylene spunbond microfiber layer. The number-average molecular weights of PVB and HPC were 200,000 g / mol and 240,000 g / mol, respectively. A comparison of PVB / HPC nanofibers with purely hydrophobic PVB nanofibers under the same experimental conditions revealed that the presence of hydrophilic domains was necessary to significantly improve photoactivity.

[0060] Example 5 (Comparative Example) Photoactivation of the nanofiber's antibacterial function can be further enhanced by encapsulating another photosensitizer with a complementary excitation spectrum to the photosensitizer already encapsulated within the polymer nanofiber under the same light irradiation conditions. Three different 10% solutions of polyvinyl butyral in ethanol, containing 0.5% RB or 0.1% TPP, or 0.5% RB and 0.1% TPP (% w / w relative to the polymer weight), were electrospun to produce nanofiber layers deposited on the surface of a polypropylene spunbond microfiber layer. The number-average molecular weight of the PVB was 200,000 g / mol. Upon excitation with white light, a synergistic effect of the two encapsulated photosensitizers was observed. Under the same conditions, nanofiber materials encapsulating two photosensitizers exhibited higher photoactivity than those encapsulating only one photosensitizer. The absorption spectra of TPP and RB do not overlap much and cover a wider region of the white light spectrum, resulting in a higher yield of singlet oxygen production under the same light irradiation. Even higher efficiency can be achieved with polymer nanofibers that combine hydrophobic and hydrophilic domains, as shown in the following example.

[0061] Example 6 Similar to Examples 1 and 5, a 16% solution of cellulose acetate and polycaprolactone (3:7 w / w) and a 0.1% solution of TPP in a chloroform-ethanol-methanol mixture (8:1:1 w / w / w) were electrospun to produce a nanofiber layer, e.g., a polypropylene spunbond microfiber layer, deposited on the surface of the base material (% w / w of the polymer). The number-average molecular weights of cellulose acetate and PCL are 50,000 g / mol and 45,000 g / mol, respectively. When excited with white light, this nanofiber material exhibits a higher singlet oxygen generation yield and higher antibacterial activity than similar materials using only one photosensitizer, because both the encapsulated photosensitizers, TPP, which absorbs in the blue region of the visible spectrum, and hypericin, which absorbs predominantly in the red region, produce singlet oxygen and contribute to the overall activity of the nanofiber material.

[0062] Example 7 A 16% solution of polystyrene (Mw = 192,000 g / mol) and polyurethane (HH8) (Mn = 120,000–180,000 g / mol) (PS:PU = 2:3 w / w) with a PEO segment to polymer chain ratio (w / w) of 7.8, as described in Example 2, in a THF / DMF mixture (7:3 w / w) was used for electrospinning polymer nanofibers with or without 10% potassium iodide (-% w / w relative to the polymer weight). As in the previous case, the encapsulated photosensitizer generates singlet oxygen upon irradiation. In addition, the photogenerated singlet oxygen mediates the photorelease of iodine and triiodide, which increases the antibacterial activity of the nanofiber material. The amount of iodine and triiodide released can be controlled by the light irradiation time.

[0063] Example 8 As in Example 5, the photoactivity of nanofibers (and their antibacterial activity) can be increased by encapsulating both a photosensitizer and an NO photodonor with a complementary excitation spectrum. For example, a 16% solution of polystyrene (Mw = 192,000 g / mol) and the polyurethane (Mn = 120,000–180,000 g / mol) (7:3) described in Example 7 in a dimethylacetamide / acetone mixture (7:3 w / w), 1% photosensitizer (ZnPC), and 1–5% NO photodonor (N-(aminopropyl)-3-(trifluoromethyl)-4-nitrobenzeneamine) were used for electrospinning of polymer nanofibers onto the base material surface (-% w / w based on the weight of the polymer). The photorelease of NO radicals, similar to the photorelease of iodine and triiodide in the previous example, enhances the antibacterial efficacy of the material.

[0064] Example 9 A 16% solution of PVDF-HFP (Mn = 130,000 g / mol) and polyurethane (Mn = 120,000–180,000 g / mol) with a preferred ratio between hydrophilic and hydrophobic moieties (described in Example 7) in a dimethylacetamide / acetone mixture (7:3 w / w) (7:3 w / w), along with 1–5% NO photodonor (N-(aminopropyl)-3-(trifluoromethyl)-4-nitrobenzeneamine), was used to electrospin polymer nanofibers onto the surface of the base material. The antibacterial effect of photoreleased NO from the nanofiber material reaches a longer distance from the material than photogenerated singlet oxygen, which has a shorter diffusion distance. The amount of NO released can be controlled by the light exposure time. Because NO is known for its broader biological effects, photorelease of NO from the material can be utilized beyond antibacterial treatment.

[0065] Example 10 The antibacterial activity of nanofiber materials can be further enhanced by combining the photorelease of three different antibacterial species in a single polymer matrix. This involves simultaneous photorelease of NO, photogeneration of singlet oxygen, and photorelease of iodine and / or triiodide mediated by the generated singlet oxygen, but the excitation spectra of the NO photodonor and photosensitizer must not overlap. A 16% solution of cellulose acetate and polycaprolactone (3:7 w / w), 0.1% acridine orange, 0.1% potassium iodide, and 1% N-(aminopropyl)-3-(trifluoromethyl)-4-nitrobenzeneamine in a chloroform-ethanol-methanol mixture (8:1:1 w / w / w) was electrospun to produce a nanofiber layer deposited on the surface of a base material, e.g., a polypropylene spunbond microfiber layer (-% w / w based on the weight of the polymer).

[0066] Example 11 During the electrospinning process, any of the antibacterial photoactive polymer nanofiber materials described in the previous examples can be simultaneously deposited onto a base layer, which is a common wound dressing, such as a wound dressing containing polyurethane foam. The presence of this photoactive layer provides additional functionality to the composite / layered wound dressing, primarily improving the healing of chronic or poorly healing wounds by preventing secondary wound infection. Alternatively, layered (or sandwich) wound dressings do not need to be assembled during the electrospinning process and can be assembled from the individual layers afterward.

[0067] Example 12 The nanofibrous polymer materials described in the previous Examples (1-10) are electrospun onto a support layer, often polypropylene spunbond, but may be produced on or combined with virtually any sheet material. Thus, the manufacturing process offers considerable versatility in the use of nanomaterials. Photoactive nanofibrous materials with antimicrobial functionality can be used in combination with other layers or as self-supporting layers, allowing for easy adaptation to the intended use. Materials can be adapted and used not only as wound dressings, but also as self-disinfecting masks and respirators, self-disinfecting filters for filtering gases and aqueous solutions, and self-disinfecting textiles and packaging materials.

[0068] Example 13 (Comparative Example) By comparing electrospun polystyrene nanofibers before and after surface modification treatments, such as sulfonation, cold plasma treatment, and polydopamine coating, we found that these treatments improved the wettability of the nanofiber membrane surface, which was originally completely hydrophobic, significantly increasing the contact between photogenerated singlet oxygen and chemical and biological targets on the nanofiber membrane surface, thereby improving the membrane's antibacterial activity. However, such modifications are time-consuming and typically impair the photophysical and / or mechanical properties of the nanofiber membrane. For example, sulfonation reduces mechanical properties and oxygen diffusivity, plasma treatment destroys photosensitizer molecules on the nanofiber surface, negatively affecting oxygen diffusivity, and the gray polydopamine coating reduces the material's transparency and limits the useful singlet oxygen pathways from the nanofiber surface.

[0069] TPP was dissolved in a 17% solution of polystyrene (MW = 192,000 g / mol) in cyclohexanone (% w / w relative to the weight of the polymer) containing 0.07% TEAB, at a concentration of 0.01 g of photosensitizer per 1 g of polymer, and processed by electrospinning to produce a nanofiber layer deposited on the surface of the base material. The material was then modified by sulfonation, oxygen plasma treatment, or polydopamine coating. For sulfonation, the nanofiber membrane was immersed in 96% sulfuric acid at room temperature for 2 hours, then washed with deionized water and neutralized with 25% aqueous ammonium hydroxide for 24 hours. For oxygen plasma treatment, the material was oxidized in high-frequency oxygen plasma using a low-pressure FEMTO plasma system (Diener Electronic GmbH & Co. KG) with a scroll vacuum pump reducing the base pressure to 8 Pa. For polydopamine coating, nanofiber membranes are immersed in ethanol for 2 minutes, followed by incubation in an aqueous solution of dopamine (2 mg / ml in 10 mM Tris, pH 8.5) for 30 minutes. This surface modification converts the hydrophobic surface of the material to a highly hydrophilic one, but this change adversely affects other important properties of the material.

[0070] Example 14 (Comparative Example) When photosensitizers (generally hydrophobic molecules) are encapsulated in nanofibers of gelatin, an example of a hydrophilic polymer, the photosensitization process requires the photosensitizer to be in a nearly monometric state, which leads to aggregation of the hydrophobic photosensitizer molecules within the nanofiber membrane and the resulting loss of their luminescence and photosensitization properties.

[0071] A 17% solution of gelatin in a formic acid:acetic acid mixture (1:3), containing dissolved TPP at a concentration of 0.01 g of photosensitizer per gram of polymer, was used to electrospin polymer nanofibers onto the surface of the base material. The fluorescence emission spectrum of the material measured immediately after electrospinning showed high fluorescence of TPP excited at 420 nm. Incubating this material in a humid environment over a beaker of water for 12 hours caused the photosensitizer to aggregate, resulting in almost complete loss of its luminescence and photooxidation properties.

[0072] Example 15 A 16% solution of polycaprolactone (Mw = 45,000 g / mol) and cellulose acetate (Mw = 50,000 g / mol) in a 7:3 (w / w) chloroform:ethanol mixture (8:2) was used to electrospin polymer nanofibers, with TPP dissolved at a concentration of 0.001 g of photosensitizer per 1 g of polymer. 2 A portion of the nanofiber membrane from ) was shaken at 90 RPM in either 4 mL of THF or 4 mL of distilled water for 12 hours at laboratory temperature. Fluorescence emission spectra of these two samples excited at 420 nm showed high TPP fluorescence in the THF sample, due to the complete dissolution of the polymer nanofibers and encapsulated photosensitizer in this solvent, whereas no TPP fluorescence was detected in the aqueous extract of this material. Thus, the photosensitizer molecules are tightly encapsulated in the polymer nanofibers and do not leach out.

[0073] Materials and Methods Antibacterial activity test Escherichia harboring the plasmid pGEM11Z (Promega, WI) A culture of E. coli DH5α (Invitrogen, CA) was incubated with agitation at 37°C in LB medium (Carl Roth, Germany) containing 1% ampicillin (Carl Roth, Germany). 8The incubation was terminated when the bacterial count reached 100 CFU / ml. The culture medium was diluted 350-fold with PBS (Carl Roth, Germany). A 1.5 x 1.5 cm TPP-encapsulated nanofiber material was placed on a sterile cotton pad in a Petri dish pre-wetted with 1500 μL of PBS. 5 μL of the diluted bacterial suspension was inoculated onto the surface of the material. After 5 minutes of incubation, the material was either irradiated with an 18W blue (420 nm) LED light (Rubylux, US) with a 400 nm long-pass filter (for UV elimination, ThorLabs) for 5 or 10 minutes or stored in the dark. The sample was then placed in an Eppendorf tube with 500 μL of PBS and vigorously shaken (IKA vortex 3) for 1 minute. After shaking, the membrane was removed, and 150 μL of the bacterial suspension was placed in duplicate on a sterile agar plate. The plate was incubated at 37°C in the dark for 15 hours to allow colonies to grow. Colony-forming unit (CFU) numbers were then calculated using OpenCFU software (Quentin Geissmann 2012-2013).

[0074] Photodynamic inactivation was calculated as the percentage of CFU of E. coli observed on agar plates after inoculation with bacteria taken from the surface of illuminated samples and dark controls.

[0075] Quantification of photooxidation processes (see J. Mosinger, B. Mosinger, Photodynamic Sensitizers Assay: Rapid and Sensitive Iodometric Measurement, Experientia, 51 (1995) 106-109. http: / / dx.doi.org / 10.1007 / BF01929349). Fiber membrane piece (2cm 2 ) was placed in a thermostated 10 mm quartz cell (22 °C) containing 3 ml of iodide detection solution. 1 Δ gThe iodide detection solution for I3 was composed of 0.02 M KI, 10 μM (NH4)2MoO4 in 0.02 M sodium-potassium phosphate buffer, pH 6.2. The cell was illuminated with visible light using a stabilized xenon lamp (500 W, Newport) with a long-pass filter (λ ≥ 400 nm, Newport). - The change in UV / VIS absorbance at 351 nm due to the formation of α-glucan was recorded at regular time intervals and compared with a blank solution of the same composition stored in the dark. The estimated total light dose (based on the lamp manufacturer's data, after 10 minutes of irradiation in the relevant spectral interval 400-700 nm) and the absorbed light dose calculated from the absorption spectrum were 83 J / cm, respectively. 2 and 8 J / cm 2 It was.

[0076] Contact angle measurement (Volpe, CD; Brugnara, M.; Maniglio, D.; Siboni, S.; Wangdu, T. (2006). "About the possibility of experimentally measuring an equilibrium contact contact angle and its theoretical and practical consequences". Contact Angle, Wettability and Adhesion. 4: 79-100)

Claims

1. 1. An antimicrobial, photoactive nanofiber polymer material comprising polymer nanofibers comprising hydrophobic and hydrophilic domains, wherein the polymer nanofibers comprise the following material: at least one hydrophobic polymer selected from polycaprolactone (PCL), polyvinyl butyral (PVB), polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(vinylidene fluoride-co-trifluoroethylene), poly(chlorotrifluoroethylene-co-vinylidene fluoride), polystyrene (PS), polydimethylsiloxane (PDMS), polypropylene (PP), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), polycarbonate, polyamide 6, and / or at least one hydrophilic polymer chosen from poly(ethylene oxide) (PEO), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), cellulose esters and / or ethers such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), cellulose acetate (CAc), chitosan, modified chitosans such as quaternized chitosan, N-alkylchitosan, carboxyalkylchitosan, acylchitosan, thiolated, sulfated and / or phosphorylated chitosan, polyacrylamide, polyacrylic acid, poly(N-isopropylacrylamide) (PNIPAA), and / or at least one copolymer having hydrophilic and hydrophobic domains chosen from poly(ε-caprolactone), copolymers of poly(ethylene oxide) / poly(ε-caprolactone) copolymer (PEO-PCL); and a polyurethane comprising hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide) and / or a polyurethane comprising linear polycarbonate diol, isophorone diisocyanate and isophorone diamine, combined with said at least one hydrophilic polymer or with said at least one hydrophobic polymer, or - polyurethanes having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide), the polyurethanes having a ratio (w / w) between the poly(ethylene oxide) domains and the rest of the polymer chain of 3 to 8, or - polyurethanes comprising linear polycarbonate diol, isophorone diisocyanate and isophorone diamine monomer units; and - at least one photoactive molecule encapsulated in the hydrophobic domains of the polymer nanofiber, said photoactive molecule being capable of releasing or generating an antimicrobial active substance after irradiation with visible light.

2. 10. The material of claim 1, wherein the polymer nanofibers comprise: - combinations of polyvinylidene fluoride copolymers with polyurethanes and / or poly(ε-caprolactone) copolymers; or - poly(ethylene oxide) and / or cellulose acetate from the group of hydrophilic polymers in combination with one or more hydrophobic polymers chosen from polyvinylidene fluoride, polystyrene, poly(vinylidene fluoride-co-hexafluoropropylene) or polycaprolactone; or poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride-co-trifluoroethylene) and / or poly(chlorotrifluoroethylene-co-vinylidene fluoride) in combination with PEO / PCL copolymers and / or polyurethanes selected from polyurethanes having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide) and polyurethanes having monomer units derived from linear polycarbonate diol, isophorone diisocyanate and isophorone diamine; or - a polyurethane having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide), the polyurethane having a ratio (w / w) between the poly(ethylene oxide) domains and the rest of the polymer chain of 3 to 8; or - Copolymer of polyethylene oxide and polycaprolactone (PEO / PCL).

3. 10. The material of claim 1, wherein the photoactive molecule is selected from at least one singlet oxygen-producing photosensitizer, at least one nitric oxide (NO) radical photodonor, and combinations thereof.

4. 10. The material of claim 1, wherein the photoactive molecule comprises a singlet oxygen-producing photosensitizer, and the material further comprises iodide ions in the form of inorganic or organic iodides.

5. 10. The material of claim 1, wherein the polymer nanofibers comprise: cellulose acetate and polycaprolactone, or PEO / PCL copolymers or a combination of polyethylene oxide and polycaprolactone; or a combination of a polyvinylidene fluoride copolymer with a polyurethane having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide), the polyurethane having a ratio (w / w) between the poly(ethylene oxide) domains and the rest of the polymer chain of 3 to 8; or - poly(vinylidene fluoride-co-hexafluoropropylene) in combination with a polyurethane having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide), the polyurethane having a ratio (w / w) between the poly(ethylene oxide) domains and the rest of the polymer chain of 3 to 8; or - a combination of polystyrene with a polyurethane having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol and poly(ethylene oxide), the polyurethane having a ratio (w / w) between the poly(ethylene oxide) domains and the rest of the polymer chain of between 3 and 8; or - A combination of polyvinyl butyral and hydroxypropyl cellulose.

6. 10. The material of claim 1, wherein the polymer nanofibers comprise a polyurethane having monomer units derived from hexamethylene diisocyanate, 1,4-butanediol, and poly(ethylene oxide), the polyurethane having a ratio (w / w) between poly(ethylene oxide) domains and the remainder of the polymer chain of 3 to 8.

7. - in the case of a combination of hydrophilic and hydrophobic polymers, the ratio of hydrophilic polymer to hydrophobic polymer ranges from 9:1 (w / w) to 1:20 (w / w); - in the case of a block copolymer comprising hydrophilic and hydrophobic domains, the ratio of hydrophilic to hydrophobic domains of the block copolymer ranges from 9:1 (w / w) to 1:20 (w / w); - In the case of a non-block copolymer in which hydrophilic and hydrophobic domains are bonded to one polymer chain, the ratio of hydrophilic to hydrophobic domains is such that the surface of the resulting nanofiber has a contact angle of less than 5 degrees, and both hydrophilic and hydrophobic domains are present in the polymer chain, according to claim 1.

8. 10. The material of claim 1, wherein the polymer nanofibers are formed by: - at least one polymer containing both hydrophilic and hydrophobic domains in the chain; - at least one polymer containing both hydrophilic and hydrophobic domains in the chain in combination with at least one hydrophilic polymer; - at least one polymer containing both hydrophilic and hydrophobic domains in the chain in combination with at least one hydrophobic polymer; a combination of at least one hydrophobic polymer and at least one hydrophilic polymer; or - a combination of at least one polymer containing both hydrophilic and hydrophobic domains in the chain, at least one hydrophilic polymer and at least one hydrophobic polymer.

9. 10. The material of claim 1, wherein the polymer nanofiber material has an optical transparency of at least 60% for at least one wavelength in the range of 400 nm to 900 nm, the optical transparency being determined based on transmittance measurements in the visible light region using a standard two-beam UV-vis spectrometer on a 0.03 mm thick sample of the polymer nanofilm in a cuvette filled with distilled water, the same solution in a second cuvette being used as a reference.

10. the singlet oxygen-producing photosensitizer is selected from free base tetraphenylporphyrin (TPP), its zinc or magnesium derivatives, zinc or aluminum phthalocyanines (ZnPc or AlPc), acridine orange (AO), toluidine blue (TB), crystal violet (CV), methylene blue (MB), malachite green (MG), rose bengal (RB), hypericin, hypocrellin A, naphthalocyanines absorbing in the near infrared region, and / or 4. The material of claim 3, wherein the NO radical photodonor is selected from 1-amino-3-(trifluoromethyl)-4-nitrobenzenamine, 4-(N-(aminopropyl)-3-(trifluoromethyl)-4-nitrobenzenamine)-7-nitrobenzofurazan, dimethylnitrobenzene, 4-nitro-3-(trifluoromethyl)aniline, 6-nitrobenzo[a]pyrene, 1-[(2'-nitrophenyl)methoxy]-2-oxo-3,3-diethyl-1-triazene, 2,6-dimethylnitrobenzene, 4-(4,4-difluoro-2,6-diiodo-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacen-8-yl)-N-(3-((4-nitro-3-(trifluoromethyl)phenyl)(nitroso)amino)propyl)butanamide.

11. 10. The material of claim 1, further comprising an inorganic or organic iodide, preferably the iodide comprises a single oxygen producing photosensitizer selected from potassium iodide, sodium iodide, magnesium iodide and calcium iodide and tetraethylammonium iodide.

12. a combination of singlet oxygen-producing photosensitizers, wherein the absorption spectra of the individual singlet oxygen-producing photosensitizers overlap at less than 70% of the wavelengths, more preferably at less than 50% of the wavelengths, even more preferably at less than 30% of the wavelengths, and even more preferably do not overlap; or a combination of NO radical photodonors, wherein the absorption spectra of the individual NO radical photodonors overlap at less than 70% of the wavelengths, more preferably at less than 50% of the wavelengths, even more preferably at less than 30% of the wavelengths, and even more preferably do not overlap; or 2. The material of claim 1, comprising a combination of a singlet oxygen generating photosensitizer and an NO radical photodonor, wherein the absorption spectra of the singlet oxygen generating photosensitizer and the NO radical photodonor overlap at less than 70% of the wavelengths, more preferably at less than 50% of the wavelengths, even more preferably at less than 30% of the wavelengths, and even more preferably do not overlap.

13. 10. The material of claim 1, further comprising magnetic or magnetizable particles encapsulated in or adsorbed onto the nanofibers, preferably the magnetic or magnetizable particles being maghemite or magnetite based particles stabilized by polyethyleneimine.

14. A method for producing a material according to any one of claims 1 to 13, comprising the steps of: - providing a solution or dispersion of a mixture of hydrophilic and hydrophobic polymers and / or copolymers having hydrophilic and hydrophobic domains; - adding to said solution or dispersion at least one single oxygen-producing photosensitizer and, optionally, at least one further I ３ － / I ２ adding an indirect photodonor and / or at least one NO radical photodonor; - producing nanofibers from said solution or dispersion, preferably on a base material or substrate, preferably by electrospinning or centrifugal spinning; - Optionally, subjecting the produced nanofibers to a chemical or physical treatment.

15. Use of a material according to any one of claims 1 to 13 as an antibacterial wound dressing, an antibacterial cosmetic facial mask, a self-sterilising facial mask or respirator, a self-sterilising filter for filtration of gases or liquids, a self-sterilising textile and article thereof, a self-sterilising packaging material or an agricultural protective foil.

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