Compostable antimicrobial film and method for applying the film to packaging

Abstract

The present disclosure relates to antimicrobial films, more particularly, to antimicrobial films for packaging perishable goods. According to one aspect, the present disclosure relates to a packaging film comprising a polymer film having a surface and an antimicrobial agent chemically bonded to the surface. According to one aspect, the present disclosure relates to a method for manufacturing a packaging film, comprising: (a) providing a polymer film having a surface; (b) modifying the surface by ultraviolet, plasma, or corona treatment; and (c) chemically bonding an antimicrobial agent to the modified surface. In one embodiment, the packaging film can be used in packaging perishable goods.

Description

[Technical Field]

[0001] Field FIELD OF THE DISCLOSURE The present disclosure relates to antimicrobial films, and more particularly to antimicrobial films for packaging of fresh produce. [Background technology]

[0002] background Packaging films are important tools for extending the shelf life of perishable goods such as food and pharmaceuticals by inhibiting microbial growth. Packaging films can benefit from the synergistic effect of a thin hydrogel layer containing an antimicrobial agent and a polymer matrix.

[0003] However, such known approaches do not offer the ability to target specific bacteria within a given packaging film and customize the antimicrobial properties to suit the contents that may be packaged therein. For example, given the increasing incidence of drug resistance among microorganisms, the suitability of single-target packaging films is limited and can quickly become obsolete.

[0004] Furthermore, such packaging films can affect the quality of their contents, for example by diffusing antimicrobial or antibiotic agents into the perishable goods. Summary of the Invention [Means for solving the problem]

[0005] BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0006] [Figure 1] 1 illustrates a diagram of a packaging film according to an embodiment of the present disclosure. [Figure 2] 1 illustrates a cross-sectional view of a packaging film according to an embodiment of the present disclosure. [Figure 3] Molecular structure of polybutylene adipate terephthalate (PBAT). [Figure 4] 1 is a flowchart illustrating a method for manufacturing a packaging film according to an embodiment of the present disclosure. [Figure 5] FIG. 1 is a schematic illustration of oxygen plasma treatment of a polymer film to form functional groups on the surface of the film. [Figure 6] 1 shows the transmittance percentage in terms of wave number (cm −1 ) in PBAT attenuated total reflectance (ATR) FTIR analysis of samples S1 to S7 in Example 1. [Figure 7] 1 shows the transmittance percentage with respect to wavenumber (cm −1 ) in PBAT ATR-FTIR of Sample S7 and Sample S7b in Example 1. [Figure 8] Figure 1 shows the antibacterial activity of functionalized PBAT films against E. coli treated on salmon after 24 hours at room temperature. [Figure 9] 1 shows photographic images of agar plates of various samples after microbiological analysis showing the visual difference between the control and plasma treated film systems. DETAILED DESCRIPTION OF THE INVENTION

[0007] Detailed Description For simplicity and clarity of description, reference numerals may be repeated among the figures to indicate corresponding or similar elements. Many details have been described to provide an understanding of the embodiments described herein. The embodiments may be practiced without these details. In other instances, well-known methods, procedures, and components have not been described to avoid obscuring the described embodiments. This specification is not to be considered as limiting the scope of the embodiments described herein.

[0008] Embodiments of the present disclosure provide compostable antimicrobial films and methods for applying the films to packaging. The present disclosure relates to antimicrobial films, and more particularly to antimicrobial films for packaging perishable goods. According to one embodiment, the present disclosure provides a packaging film comprising a polymer film having a surface and an antimicrobial agent chemically bonded to the surface. According to another embodiment, the present disclosure provides a method of manufacturing a packaging film comprising: (a) providing a polymer film having a surface; (b) modifying the surface by ultraviolet, plasma, or corona treatment; and (c) chemically bonding an antimicrobial agent to the modified surface. In one embodiment, the packaging film can be used for packaging perishable goods.

[0009] Some examples of known packaging films are as follows: KR101417767B1 teaches an antimicrobial food packaging film comprising chitosan and an inorganic antimicrobial agent, and a method for producing the same; CH713367B1 teaches a method for extending the refrigerated shelf life of de-shelled shrimp by maintaining its freshness with an antimicrobial active in combination with maintaining freshness under a modified atmosphere; and US Patent No. 10494493B1 teaches a biodegradable composite film with antimicrobial properties consisting of nanocellulose fibrils, chitosan, and S-nitroso-N-acetylpenicillamine (SNAP) for food packaging applications. Other examples are described in WO 2018106191A1, CN110105612A, CN110591300A, KR20190119501A, CN110127769, U.S. Patent No. 20060154894A1, WO 2019113520, U.S. Patent Application Publication No. 2012232191, and U.S. Patent Application Publication No. 20180340049, but this is not an exhaustive list.

[0010] Given the shortcomings of existing antimicrobial packaging technologies, embodiments of the present disclosure seek to create customizable packaging films to address the emergence of drug resistance, allowing various antimicrobial agents to be used alone or in combination. This may, for example, increase the suitability of a given packaging film, or film type, for an increasing number of microbial targets. Furthermore, customization may enable targeting of the most commonly found microorganisms depending on the package contents.

[0011] In one embodiment, an antimicrobial film according to the present disclosure is produced by chemically bonding a thin layer of hydrogel, such as PBAT, onto the surface of a substrate to impart antimicrobial properties. The mechanism of action of the film is to have an antimicrobial surface that is effective upon contact with fresh produce, rather than via antimicrobial agents diffusing from the surface into the food.

[0012] The thin hydrogel layer may be composed of an IgY antibody and chitosan.

[0013] IgY against E. coli can be produced by immunizing chickens with inactivated E. coli, resulting in the production of IgY in egg yolk. Chitosan, which also has antibacterial properties, can be used to immobilize IgY on the PBAT surface and also provide a matrix component for a hydrogel that swells upon contact with the surface of, for example, a fish fillet.

[0014] The use of IgY antibodies may allow for customization of antimicrobial properties to target specific microorganisms, such as bacteria. This ability to specifically target bacteria and customize formulations according to the most harmful microorganisms for a given fresh product may enhance the shelf life of that food.

[0015] Unlike broad-spectrum antibacterial agents, IgY can be produced to target resistant bacteria that may be resistant to commonly used antibacterial agents. The experiments herein were performed using IgY produced against E. coli. However, IgY against other microorganisms, such as the three major spoilage bacteria in fresh salmon, is also possible.

[0016] FIG. 1 illustrates a diagram of a packaging film according to an embodiment of the present disclosure. The packaging film according to an embodiment of the present disclosure includes a polymer film having a surface and an antimicrobial agent chemically bonded to the surface. FIG. 1 shows an embodiment of a packaging film (10) having a surface (12) and an antimicrobial agent (14) bonded to the surface via a chemical bond (16). The packaging film further includes a hydrogel layer disposed on the surface, which may include the antimicrobial agent. In one embodiment, the hydrogel layer is the antimicrobial agent. In another embodiment, the hydrogel layer is bonded to the antimicrobial agent.

[0017] Figure 2 illustrates a cross-sectional view of a packaging film according to an embodiment of the present disclosure. The embodiment of Figure 2 shows a packaging film (20) having a hydrogel layer (22) disposed thereon, the hydrogel layer (22) including an antimicrobial agent.

[0018] The antimicrobial agent can be any suitable agent for inhibiting microbial growth. The antimicrobial agent can be an antimicrobial compound, peptide, protein, enzyme, polymer, or essential oil. The antimicrobial agent can be a bacteriocin. The antimicrobial agent can be an antibody. The antimicrobial agent can be an immunoglobulin. The antimicrobial agent can be immunoglobulin Y (IgY). The antimicrobial agent can be a polysaccharide. The antimicrobial agent can be chitosan. The antimicrobial agent can be IgY and chitosan. IgY and chitosan can each be bound to a surface, independently of one another. IgY can be bound to chitosan, and chitosan can be bound to a surface. Chitosan can be bound to IgY, and IgY can be bound to a surface. Chitosan can form a hydrogel layer, but can also be considered an antimicrobial agent. The antimicrobial agent can include two or more components. The antimicrobial agent can include two or more components that are bound to a surface, independently of one another. The antimicrobial agent can include two or more components, one component bound to a surface, and a second component bound to the first component. The components may be directly linked or may be linked via an additional linker. Two or more components may be linked sequentially.

[0019] The antimicrobial agent can be immunoglobulin Y (IgY). The IgY can be against bacteria, viruses, or fungi. The IgY can be against viruses such as Sars-Cov-2. The IgY can be against bacteria, such as spoilage or contaminating bacteria. The IgY can be against bacteria selected from the group consisting of Escherichia coli, Shewanella putrefaciens, Pseudomonas fluorescens, Photobacterium phosphoreum, Listeria monocytogenes, Lactobacillus acidophilus, and Clostridium botulinum. The IgY can be against Escherichia coli (E. coli). The IgY can be IgY against viruses such as SARS-related coronaviruses, e.g., SARS-CoV and SARS-CoV-2, influenza A and B, e.g., A H1N1, H3N2, or B Victoria and Yamagata strains. IgY can be isolated from chicken egg yolk. IgY against E. coli can be isolated from chicken egg yolk produced in chickens immunized with whole inactivated E. coli. IgY can also be produced by other suitable techniques, such as methods well known in the art (see, e.g., References [1-4]).

[0020] The terms chemically bonded, covalently bonded, and cross-linked may be used interchangeably. Chemically bonded includes any means of attaching an antimicrobial agent to a surface, such as by covalent bond formation. For example, an antimicrobial agent may be covalently bonded to a hydrogel by an amide bond. The hydrogel may be chemically bonded to a film surface. The hydrogel itself may be an antimicrobial agent. The hydrogel may be a weak antimicrobial agent. The hydrogel may not be an antimicrobial agent, but may be attached to an antimicrobial agent.

[0021] The hydrogel layer may comprise one or more polymers. The hydrogel layer may be natural, naturally derived, or synthetic. The hydrogel layer may be selected from dextran, cellulose and its derivatives (e.g., carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxypropylmethylcellulose, cellulose acetate phthalate), hyaluronic acid, chitosan, gelatin, starch, pectin, alginate, polyacrylamide, polyacrylic acid, polymethylmethacrylate, polylactic acid, polyvinylpyrrolidone, poly(2-hydroxyethylmethacrylate), and combinations thereof.

[0022] Figure 3 shows the chemical structure of PBAT. In one embodiment, the polymer film can be polybutylene adipate terephthalate (PBAT). The polymer film can be compostable or biodegradable.

[0023] The polymer film may comprise one or more polymers. The polymer film may be a compostable or biodegradable polymer. The polymer film may be polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, a cellulosic material, polyglycolic acid, polycaprolactone, polyvinyl alcohol, a carbohydrate-based material, a protein-based material, or a combination thereof. The polymer film may be a non-biodegradable polymer. The polymer film may be polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, or a combination thereof. The polymer film may comprise polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, a cellulosic material, polyglycolic acid, polycaprolactone, polyvinyl alcohol, a carbohydrate-based material, a protein-based material, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, or a combination thereof.

[0024] Packaging films according to embodiments of the present disclosure may contain other ingredients. Packaging films may specifically exclude other ingredients. Packaging films may be substantially free of or completely free of inorganic ingredients. Packaging films are antibiotic-free. As used herein, "antibiotics" may be used interchangeably with antibiotic small molecules and encompass small molecule antibiotics with various mechanisms of action, such as targeting cell walls / membranes or interfering with bacterial enzymes. As used herein, the term "antimicrobial agent" or "antimicrobial drug" includes, for example, IgY, a protein that primarily targets the bacterial surface and may induce its antibacterial action through structural changes to the bacterial surface. [5] As used herein, the term "substantially free" means about 30% by weight or less. As used herein, the term "completely free" means about 1% by weight or less.

[0025] Packaging films according to embodiments of the present disclosure may be used in any suitable packaging product, such as a film, a tray, or a solid substrate.

[0026] 4 is a flow chart illustrating a method of manufacturing a packaging film according to an embodiment of the present disclosure. In one embodiment, the method includes the steps of: (a) providing a polymer film having a surface; (b) modifying the surface by ultraviolet, plasma, or corona treatment; and (c) chemically bonding an antimicrobial agent to the modified surface. The method may include forming a polymer into a polymer film prior to step (a).

[0027] The method may include extruding a polymer resin into a polymer film by film blowing or film casting. It will be understood that other suitable means of forming a polymer film may be used without departing from the scope of the present disclosure. The polymer film may be formed from polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, or combinations thereof. The polymer film may be formed from PBAT.

[0028] The polymer film may have a thickness of about 10 to about 500 μm. The polymer film may have a thickness of about 80 μm. The polymer film may have a thickness of about 10 μm, about 20 μm, about 30 μm, about 40 μm, about 50 μm, about 60 μm, about 70 μm, about 75 μm, about 80 μm, about 85 μm, about 90 μm, about 100 μm, about 200 μm, about 300 μm, about 400 μm, or about 500 μm. The polymer film may have a thickness of about 20 to about 100 μm, about 30 to about 100 μm, about 40 to about 100 μm, about 50 to about 100 μm, about 60 to about 100 μm, about 70 to about 100 μm, about 80 to about 100 μm, about 90 to about 100 μm, about 100 to about 200 μm, about 200 to about 300 μm, about 300 to about 400 μm, about 400 to about 500 μm, about 250 to about 500 μm, about 100 to about 500 μm, about 70 to about 90 μm, about 80 to about 90 μm, about 70 to about 80 μm, about 75 to about 85 μm, or about 79 to about 81 μm.

[0029] The step of modifying the surface of the polymer film by ultraviolet, plasma, or corona treatment ("step (b)" or "modification step") can be carried out by any suitable procedure or method. The surface can be modified using treatment with ultraviolet light of an appropriate wavelength. For example, the modification step can be carried out in the presence of ultraviolet light of about 100 to about 400 nm, or about 254 nm, at a power of 1 to 500,000 milliwatts, and for an exposure time of about 1 to 216,000 seconds, or about 60 seconds. For example, arc discharge, corona discharge, or dielectric barrier discharge can be used. Additionally, atmospheric pressure plasma can be used. The modification step can be carried out in a plasma chamber in the presence of oxygen. The modification step can be carried out in a plasma chamber at about 5 to about 1000 watts. The modification step can be carried out at about 200 watts. The modification step can be carried out at about 5, about 10, about 20, about 50, about 100, about 150, about 200, about 250, about 300, about 350, about 400, about 450, about 500, about 600, about 700, about 800, about 900, or about 1000 watts. The modification step can be carried out at about 150 to about 250 watts, about 150 to about 200 watts, about 200 to about 250 watts, about 100 to about 300 watts, about 100 to about 400 watts, about 100 to about 500 watts, about 100 to about 1000 watts, about 500 to about 1000 watts, about 750 to about 1000 watts, or about 50 to about 500 watts. The modification step can be carried out at an appropriate pressure, for example, about 250 to about 760 mTorr. The modification step may be carried out at atmospheric pressure. The modification step may be carried out in an amount appropriate to achieve surface modification of the polymer film. The modification step may be carried out for milliseconds to several minutes. The modification step may be carried out for about 100 milliseconds to about 10 minutes. The modification step may be carried out for about 3 minutes. The modification step may be carried out for about 1 minute, about 2 minutes, about 4 minutes, or about 5 minutes. The modification step may be carried out for less than 1 minute. The modification step may be carried out for more than 5 minutes.

[0030] The modification step may include treating the surface with a solution after UV, plasma, or corona treatment. The solution may be any solution suitable for promoting surface modification of a polymer film. The solution may include a carboxylic acid. As used herein, the term "carboxylic acid" refers to a carboxylic acid or any molecule containing a reactive carboxyl chemical group. For example, the carboxylic acid may be formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, fumaric acid, malic acid, acrylic acid, citric acid, gluconic acid, itaconic acid, adipic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, keto acids, aspartic acid, glutamic acid, sodium acetate, potassium acetate, ammonium acetate, or vinyl acetate, or a combination thereof. The carboxylic acid may be acetic acid, citric acid, or acrylic acid. The solution may be about 25% to about 99% acetic acid in water. The solution can be about 25%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, or about 99% acetic acid in water, or about 25%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, or about 99% acetic acid in any suitable solvent. The solution can be glacial acetic acid or about 100% acetic acid. The modification step can include rinsing the surface with water after treating the surface with the solution. The modification step can include rinsing the surface with any suitable solvent after treating the surface with the solution.

[0031] The step of chemically binding the antimicrobial agent to the modified surface ("step (c)," or "binding step") can be carried out by any suitable procedure or method. Chemical binding can include covalent bonding, cross-linking, or any means of binding the antimicrobial agent to the surface. The antimicrobial agent can be covalently bound to the surface by an amide bond. The binding step can include cross-linking the antimicrobial agent to the modified surface in the presence of a cross-linking agent. The cross-linking agent can be 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The binding step can include treating the modified surface with the antimicrobial agent, EDC, and NHS in aqueous solution. The binding step can include treating the modified surface with chitosan, IgY, EDC, and NHS in solution. The bonding step can include treating the modified surface with chitosan, IgY, EDC, and NHS to form a film having a chitosan hydrogel layer disposed on the surface, and forming amide bonds between (i) the chitosan and the film, (ii) the chitosan and IgY, and / or (iii) the IgY and the film. The bonding step can be carried out under any conditions suitable for crosslinking the antimicrobial agent and the modified surface. The bonding step can be carried out at about 20 to about 60°C, e.g., about 40°C. The bonding step can be carried out at about room temperature to about 65°C. The bonding step can be carried out for about 100 milliseconds to about 1 hour. The bonding step can be carried out for about 15 minutes, about 30 minutes, about 45 minutes, or about 1 hour. The bonding step can be carried out for more than about 1 hour. The bonding step can be carried out for less than about 15 minutes. The bonding step can be carried out for less than 1 minute, e.g., less than 1 second.

[0032] The method of manufacturing a packaging film may include washing the film to remove unreacted crosslinking agent and / or unbound antimicrobial agent. Washing may be done with water or any other suitable solvent.

[0033] The packaging films described herein may be used for any suitable purpose. The packaging film may be used to package perishable goods or related devices. The perishable goods may be food, chemicals, pharmaceuticals, plants, or animal products. The perishable goods may be foodstuffs. The foodstuffs may be meat, poultry, pork, fruits, vegetables, or seafood. The foodstuffs may be fish, such as salmon, European bass, tilapia, halibut, cod, flounder, sea bass, walleye, catfish, tuna, yellowtail, amberjack, snapper, saury, grouper, trout, blue perch, mackerel, sardines, or herring. The foodstuffs may be whole fish or portions of fish, such as fish fillets. The entire package may be comprised of the packaging film, or the packaging film may be only one component of the package. The surface of the film may be configured to contact the surface of the perishable goods. The hydrogel layer of the film may be configured to contact the surface of the perishable goods. The antimicrobial agent can remain substantially bound to the film and cannot diffuse into the fresh produce. The packaging can inhibit microbial growth on fresh produce. The packaging can inhibit bacterial growth on fresh produce. The packaging can inhibit bacterial growth on fresh produce by up to 1 in 10,000 (i.e., 4-log) versus a control of PBAT film without the antimicrobial surface. The packaging, or portions of the packaging, can be compostable or biodegradable. The packaging can be used in medical applications, such as wound care. The packaging can be used for cannabis-related packaging, such as packaging for cannabis plants or products. The packaging can be used for other applications, such as meal kits, filtration membranes, water treatment, and textile materials.

[0034] The packaging films described herein can be customized to target specific bacteria. The packaging films have the ability to target bacteria that have developed resistance to other antimicrobial agents. The ease of customization of the films can allow them to be used in packaging a variety of products. [Example]

[0035] Example 1 Polybutylene adipate terephthalate (PBAT) is a polymer with the chemical structure shown in Figure 3. Plasma O2 treatment of a polymer film can be performed as shown in Figure 5. Figure 5 is a schematic diagram of oxygen plasma treatment of a polymer film, which forms functional groups on the surface of the film. The functional groups formed on the surface of a PBAT film after oxygen plasma treatment can include carboxyl groups, alcohols, and epoxides. The carboxyl groups are then crosslinked to amines using an EDC / NHS crosslinker. For example, ethanolamine can be used as a model amine to test the crosslinking reaction. FTIR can then be used to detect the formed amide bonds.

[0036] A series of PBAT samples (Samples 1-7) were prepared using PBAT films that had been previously fabricated by extruding PBAT resin into 80 μm thick sheets. This can be done, for example, by film blowing or film casting. Samples (S1-S7) were prepared as follows:

[0037] Sample 1 (S1): PBAT film S1 was prepared as follows: the PBAT film was washed with water, and no other treatments for modification were applied.

[0038] Sample 2 (S2): PBAT + acetic acid (AA) S2 was prepared as follows: PBAT films were placed in glacial acetic acid for 5 min and washed three times with water.

[0039] Sample 3 (S3): PBAT + EDC + NHS + ETH amine S3 was prepared as follows: a PBAT film was immersed in a solution of EDC, NHS, and ethanolamine for 1 hour, and then washed with water three times.

[0040] Sample 4 (S4). High-power PBAT+EDC+NHS+ETH amine (PH-EDC) plasma in O2 (180 seconds). S4 was prepared as follows: the PBAT film was placed in a plasma chamber at 400 watts and 250 millitorr for 3 minutes. The film was then immersed in a solution of EDC, NHS, and ethanolamine for 1 hour. The film was then washed three times with water.

[0041] Sample 5 (S5). Medium-power plasma O2 (180 seconds) with PBAT+EDC+NHS+ETH amine (PM-EDC). S5 was prepared according to the method of S4, using medium power (200 W) instead of high power (400 W).

[0042] Sample 6 (S6). AA, followed by a high-power soak in PBAT+EDC+NHS+ETH amine (PH-AA-EDC) in plasma O (180 seconds). S6 was prepared as follows: The PBAT film was placed in a plasma chamber at 400 watts and 250 millitorr for 3 minutes. The film was then immersed in a glacial acetic acid solution for 5 minutes. The film was then washed three times with water and then placed in a solution of EDC, NHS, and ethanolamine for 1 hour. The film was then washed three times with water.

[0043] Sample 7 (S7). AA, followed by a medium-power soak in PBAT+EDC+NHS+ETH amine (PM-AA-EDC) in plasma O (180 seconds). S7 was prepared according to the method of S6, using medium power (200 W) instead of high power (400 W).

[0044] Samples S1 to S7 were placed in a vacuum oven 4 hours before analysis. The samples were measured using a Bruker Alpha II instrument with a diamond crystal. -1 The spectrum was acquired at a resolution of 4 cm. -1 32 scans were performed per sample. The background was automatically removed by the software. The expected peak of secondary amide was a strong peak (1700-1650 cm). -1 ), intermediate peak (1580-1500 cm -1), and intermediate peak (3400-3100 cm -1 )

[0045] Figure 6 shows the ATR-FTIR analysis of samples S1 to S7. For example, Figure 6 shows the wavenumber (cm) in the PBAT attenuated total reflectance (ATR) FTIR analysis of samples S1 to S7. -1 ) is the transmittance percentage. According to FIG. 6, S7 is, for example, the transmittance percentage at 1560 cm -1 , 1645cm -1 , and 3295 cm -1 The presence of a peak indicates the formation of most amide bonds on the surface.

[0046] Figure 7 shows the ATR-FTIR analysis of the treated (front) surface of sample S7 (S7) and the back surface of the film of sample 7 (S7b). According to Figure 7, amide bonds were only formed on the surface exposed to plasma.

[0047] Example 2 PBAT film is produced by extruding the PBAT resin into a sheet having a thickness of 80 μm, which can be done, for example, by film blowing or film casting.

[0048] The sheet is then cut into film samples of the desired size for experimental or commercial purposes, for example, the sheet can be cut into 1 cm x 1 cm squares.

[0049] A notch or other identification means may be applied to indicate the active surface of the film.

[0050] An activation solution is then prepared as follows.

[0051] First, 100 mL of a 2.5 mg / mL chitosan solution is prepared in 0.06 M HCl (stock solution). For experimental purposes, the pH of a desired volume of chitosan solution can be adjusted by adding 1 M sodium hydroxide dropwise.

[0052] Second, a 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) solution is prepared from a stock solution of 20 mg / mL EDC in distilled water.

[0053] Third, an N-hydroxysuccinimide (NHS) solution is prepared from a stock solution of 20 mg / ml NHS in distilled water.

[0054] Fourth, an IgY antibody solution is prepared from a 21.5 mg / mL IgY stock solution in phosphate buffer solution. The IgY antibody used in this protocol was manufactured by Exalpha Biologics specifically for Escherichia coli (E. coli).

[0055] An antimicrobial PBAT film is then fabricated as follows.

[0056] The PBAT sample film was placed in a plasma chamber and treated with oxygen at 250 mTorr and 200 W for 3 minutes. The top surface exposed to the plasma is considered the treated surface (i.e., the active or antimicrobial surface), while the bottom surface is not.

[0057] Immediately after plasma treatment, the film samples are immersed in 99% acetic acid for 5 minutes.

[0058] The film sample is then washed 3 to 4 times with distilled water.

[0059] To functionalize the films and impart an antibacterial surface, two film samples were placed in 2 mL low-bind Eppendorf tubes. 1.6 mL of a 2.5 mg / mL chitosan solution and 18 μL of a 0.2 mg / mL IgY solution were added to the Eppendorf tubes. Then, 0.2 mL each of freshly prepared EDC and NHS solutions were added to the Eppendorf tubes to achieve a final concentration of 2 mg / mL. The film samples were then left for 1 hour to allow the cross-linking reaction to occur.

[0060] The film samples were then washed thoroughly with water 3 to 4 times for 10 minutes each to completely remove unreacted EDC, NHS, and chitosan and IgY unbound to the film samples.

[0061] The film samples are then allowed to dry at room temperature for 15 minutes and stored in a Petri dish until needed.

[0062] Before use, wash the film sample with water 3-4 times for 10 minutes.

[0063] Example 3 Effect of compostable active films on E. coli-treated salmon after 24 hours at room temperature (RT) the purpose: 1. Grafting of chitosan / IgY onto PBAT film 2. In situ testing of the developed films on salmon fish inoculated with E. coli

[0064] method: Three types of samples were prepared: 1. PBAT film (control): A PBAT film was prepared according to the method of Example 1, Sample 1. 2. Plasma-treated PBAT film (PBAT+plasma): PBAT film was prepared by placing the PBAT film in a plasma chamber and treating it with oxygen at 200 W and 250 mTorr for 3 minutes. 3. PBAT film grafted with chitosan and IgY (PBAT+System): According to the method of Example 2, PBAT film was crosslinked with chitosan and IgY.

[0065] To test the specific antibacterial effect of the film against E. coli, other bacteria on the fish were first removed by sterilization with a 2.5% chlorine solution (calcium hypochlorite 70% Ca(ClO)2). The fish samples were then washed three times with water before being inoculated with E. coli.

[0066] Precultured Escherichia coli (E.coli)10 5 ~10 6 CFU / ml was inoculated into 0.3 g of salmon sample in a volume of 10 μL. The fish sample was placed in a Petri dish covered with one of three types of PBAT film samples (two sheets - one above and one below the fish sample, 1.5 cm). 2 ).

[0067] result FIG. 8 shows the antibacterial activity of functionalized PBAT films against treated E. coli on salmon fish after 24 hours at room temperature.

[0068] FIG. 9 shows photographic images of the agar plates of the different samples after microbiological analysis, demonstrating the visual difference between the control and the plasma-treated film system.

[0069] E. coli growth in the control sample reached 6.95 log (CFU / mL) after a 24 hour incubation period at room temperature (RT).

[0070] For samples incubated with plasma-treated PBAT films, bacterial growth was 6.65 log CFU / mL.

[0071] For samples treated with functionalized (i.e., active) film, growth was 3.28 log CFU / mL, representing a reduction of approximately 3.3 log CFU / mL after 24 hours of incubation compared to the control sample.

[0072] The experimental results demonstrate significant antimicrobial activity of the activated PBAT film against Escherichia coli (E. coli). Similarly, this platform technology can include IgY produced against specific spoilage organisms (SSOs) involved in the spoilage of various fresh produce to extend shelf life. The ability to customize the activated film also allows for targeting of resistant bacteria, allowing for broad-spectrum protection (i.e., using an antigen general to all Gram-negative bacteria to immunize chickens) or highly specific targeting (i.e., an antigen specific to one bacterial species).

[0073] In the foregoing description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that these specific details are not required.

[0074] The structures, features, accessories, and alternatives of the specific embodiments described herein and shown in the drawings are intended to apply generally to all of the teachings of the present disclosure, including all of the embodiments described and illustrated herein, to the extent they are compatible. That is, the structures, features, accessories, and alternatives of the specific embodiments are not intended to be limited to only the specific embodiments, unless specified.

[0075] Additionally, the steps and order of steps of the methods described herein are not meant to be limiting: methods comprising different steps, a different number of steps, and / or a different order of steps are also contemplated.

[0076] The above-described embodiments are intended to be merely illustrative. Alterations, modifications, and variations may be made to the particular embodiments by those skilled in the art without departing from the scope, which is defined solely by the claims appended hereto. Further numbered embodiments are set forth below.

[0077] Embodiments: Embodiment 1. a polymer film having a surface; antimicrobial agents chemically bound to its surface; Packaging films, including Embodiment 2. 10. The film of embodiment 1, further comprising a hydrogel layer disposed on the surface thereof, the hydrogel layer comprising an antimicrobial agent. Embodiment 3. 3. The film of embodiment 2, wherein the hydrogel layer comprises a natural, naturally derived, or synthetic polymer. Embodiment 4. 4. The film of embodiment 3, wherein the hydrogel layer comprises a polymer selected from the group consisting of dextran, cellulose, cellulose derivatives (e.g., carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose hydroxypropyl methyl cellulose, cellulose acetate phthalate), hyaluronic acid, chitosan, gelatin, starch, pectin, alginate, polyacrylamide, polyacrylic acid, polymethyl methacrylate, polylactic acid, polyvinylpyrrolidone, poly 2-hydroxyethyl methacrylate, and combinations thereof. Embodiment 5. 5. The film of any one of claims 1-4, wherein the antimicrobial agent is selected from the group consisting of antimicrobial compounds, antimicrobial peptides, antimicrobial proteins, antimicrobial enzymes, antimicrobial polymers, and antimicrobial essential oils. Embodiment 6. 6. The film of any one of embodiments 1 to 5, wherein the antimicrobial agent is selected from the group consisting of immunoglobulin Y (IgY), chitosan, and combinations thereof. Embodiment 7. 7. The film of any one of embodiments 1-6, wherein the antimicrobial agent comprises immunoglobulin Y (IgY). Embodiment 8. 8. The film of any one of embodiments 1-7, wherein the antimicrobial agent comprises immunoglobulin Y (IgY) and chitosan. Embodiment 9. 9. The film of embodiment 8, wherein the IgY and chitosan are each, independently of one another, bound to the surface. Embodiment 10. 9. The film of embodiment 8, wherein the IgY is bound to chitosan and the chitosan is bound to the surface. Embodiment 11. 9. The film of embodiment 8, wherein the chitosan is bound to the IgY and the IgY is bound to the surface. Embodiment 12. 12. The film of any one of embodiments 7 to 11, wherein the IgY is an IgY against bacteria, viruses, or fungi. Embodiment 13. 13. The film of embodiment 12, wherein the virus is selected from the group consisting of SARS-associated coronavirus, SARS-CoV, SARS-CoV-2, influenza A, influenza A H1N1, influenza A H3N2, influenza B Victoria lineage, and influenza B Yamagata lineage. Embodiment 14. 13. The film of embodiment 12, wherein the bacteria is spoilage or contaminating bacteria. Embodiment 15. 15. The film of embodiment 14, wherein the spoilage bacteria are selected from the group consisting of Escherichia coli, Shewanella putrefaciens, Pseudomonas fluorescens, Photobacterium phosphoreum, Listeria monocytogenes, lactic acid bacteria, and Clostridium botulinum. Embodiment 16. 16. The film of embodiment 15, wherein the spoilage bacteria is E. coli. Embodiment 17. 17. The film of embodiment 16, wherein the IgY to E. coli is isolated from chicken egg yolk produced in chickens immunized with whole inactivated E. coli bacteria. Embodiment 18. 18. The film of any one of embodiments 1-17, wherein the antimicrobial agent is chemically bonded to the surface by a covalent bond. Embodiment 19. 19. The film of embodiment 18, wherein the antimicrobial agent is chemically bonded to the surface by an amide bond. Embodiment 20. 20. The film of any one of the preceding claims, wherein the polymer film comprises a polymer selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof. Embodiment 21. 21. The film of embodiment 20, wherein the polymer is PBAT. Embodiment 22. 22. The film of any one of embodiments 1 to 21, which is substantially free of inorganic components. Embodiment 23. 22. The film of any one of embodiments 1 to 21, which is completely free of inorganic components. Embodiment 24. 24. The film of any one of embodiments 1 to 23, which is completely free of antibiotics. Embodiment 25. 25. The film of any one of embodiments 1 to 24, which is compostable. Embodiment 26. 26. The film of any one of embodiments 1 to 25, used in a packaging product selected from the group consisting of films, trays, and solid substrates. Embodiment 27. (a) providing a polymeric film having a surface; (b) modifying the surface by ultraviolet, plasma or corona treatment; and (c) chemically bonding antimicrobial agents to the modified surface; A method for producing a packaging film, comprising: Embodiment 28. 28. The method of embodiment 27, wherein step (c) further comprises chemically bonding a hydrogel layer to the modified surface. Embodiment 29. 28. The method of embodiment 27, further comprising, before step (a), forming the polymer into a polymer film. Embodiment 30. 30. The method of embodiment 29, wherein forming the polymer into a polymer film comprises extruding the polymer resin into a polymer film by film blowing or film casting. Embodiment 31. 31. The method of any one of embodiments 27-30, wherein the polymer is selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof. Embodiment 32. 32. The method of embodiment 31, wherein the polymer is PBAT. Embodiment 33. 33. The method of any one of embodiments 27 to 32, wherein the polymer film has a thickness of about 10 to about 500 μm. Embodiment 34. 33. The method of any one of embodiments 27-32, wherein the polymer film has a thickness of about 80 μm. Embodiment 35. 35. The method of any one of embodiments 27-34, wherein step (b) comprises treating the surface in a plasma chamber in the presence of oxygen. Embodiment 36. 36. The method of embodiment 35, wherein in step (b), the plasma chamber is between about 5 Watts and about 1000 Watts. Embodiment 37. 37. The method of embodiment 35 or 36, wherein in step (b), the plasma chamber is at about 250 to about 760 mTorr. Embodiment 38. 38. The method according to any one of embodiments 35 to 37, wherein step (b) is carried out for about 100 milliseconds to about 10 minutes. Embodiment 39. 39. The method of any one of embodiments 35 to 38, wherein step (b) further comprises treating the surface with a solution after the UV, plasma, or corona treatment. Embodiment 40. 40. The method of embodiment 39, wherein the solution comprises a carboxylic acid. Embodiment 41. 41. The method of embodiment 40, wherein the carboxylic acid is selected from the group consisting of formic acid, acetic acid, chloroacetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, fumaric acid, malic acid, acrylic acid, citric acid, gluconic acid, itaconic acid, adipic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, keto acids, aspartic acid, glutamic acid, sodium acetate, potassium acetate, ammonium acetate, vinyl acetate, and combinations thereof. Embodiment 42. 42. The method of any one of embodiments 39-41, wherein the solution is about 5 to about 99% acetic acid in water. Embodiment 43. 42. The method of any one of embodiments 39-41, wherein the solution is 100% (glacial) acetic acid. Embodiment 44. 44. The method of any one of embodiments 39-43, wherein step (b) further comprises rinsing the surface with water after treating the surface with the solution. Embodiment 45. 45. The method of any one of embodiments 27-44, wherein step (c) comprises crosslinking the antimicrobial agent to the modified surface in the presence of a crosslinking agent. Embodiment 46. 46. ​​The method of embodiment 45, wherein the cross-linking agent comprises 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Embodiment 47. 47. The method of embodiment 46, wherein step (c) comprises treating the modified surface with an antimicrobial agent, EDC, and NHS in aqueous solution. Embodiment 48. 48. The method of any one of embodiments 45 to 47, wherein step (c) is carried out at about 20 to about 60°C. Embodiment 49. 49. The method of any one of embodiments 45-48, wherein step (c) is carried out for about 100 milliseconds to about 1 hour. Embodiment 50. 50. The method of any one of embodiments 45-49, further comprising (d) washing the film to remove unreacted crosslinking agent and unbound antimicrobial agent. Embodiment 51. 51. The method of any one of embodiments 27-50, wherein the hydrogel layer comprises a natural, naturally derived, or synthetic polymer. Embodiment 52. 52. The method of embodiment 51, wherein the hydrogel layer comprises a polymer selected from the group consisting of dextran, cellulose, cellulose derivatives (e.g., carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose hydroxypropylmethylcellulose, cellulose acetate phthalate), hyaluronic acid, chitosan, gelatin, starch, pectin, alginate, polyacrylamide, polyacrylic acid, polymethylmethacrylate, polylactic acid, polyvinylpyrrolidone, poly 2-hydroxyethylmethacrylate, and combinations thereof. Embodiment 53. 51. The method of any one of embodiments 27-50, wherein the antimicrobial agent is selected from the group consisting of antimicrobial compounds, antimicrobial peptides, antimicrobial proteins, antimicrobial enzymes, antimicrobial polymers, and antimicrobial essential oils. Embodiment 54. 54. The method of any one of embodiments 27-53, wherein the antimicrobial agent is selected from the group consisting of immunoglobulin Y (IgY), chitosan, and combinations thereof. Embodiment 55. 55. The method of any one of embodiments 27-54, wherein the antibacterial agent comprises immunoglobulin Y (IgY). Embodiment 56. 56. The method of any one of embodiments 27-55, wherein the antimicrobial agent comprises immunoglobulin Y (IgY) and chitosan. Embodiment 57. 57. A packaging film produced according to the method of any one of embodiments 27 to 56. Embodiment 58. 58. The packaging film of embodiment 57, which is compostable. Embodiment 59. 60. Use of the film of any one of embodiments 1 to 25, 57 or 58 in packaging for perishable goods. Embodiment 60. The use of embodiment 59, wherein the perishable product is selected from the group consisting of food, chemicals, pharmaceuticals, devices, plants, and animal products. Embodiment 61. The use according to embodiment 59 or 60, wherein the perishable product is a food product. Embodiment 62. The use of embodiment 61, wherein the food product is selected from the group consisting of meat, poultry, pork, fruit, vegetables, or seafood. Embodiment 63. The use according to embodiment 62, wherein the food product is meat. Embodiment 64. The use according to embodiment 62, wherein the food is fish. Embodiment 65. 65. The use according to any one of embodiments 59 to 64, wherein the surface of the film is configured to contact the surface of the perishable item. Embodiment 66. 66. The use of any one of embodiments 59 to 65, wherein the antimicrobial agent remains substantially bound to the film and does not diffuse into the fresh produce. Embodiment 67. 67. The use according to any one of embodiments 59 to 66, wherein the packaging inhibits microbial growth on perishable goods. Embodiment 68. The use according to any one of embodiments 59 to 67, wherein the packaging inhibits microbial growth on perishable goods. Embodiment 69. 69. The use of any one of embodiments 59 to 68, wherein the film is compostable.

[0078] References 1. Abbas, AT, et al., IgY antibodies for the immunoprophylaxis and therapy of respiratory infections. Hum Vaccin Immunother, 2019. 15(1): p. 264-275. 2. Hu, B., et al., The preparation and antibacterial effect of egg yolk immunoglobulin (IgY) against the membrane outer proteins of Vibrio parahaemolyticus. J Sci Food Agric, 2019. 99(5): p. 2565-2571. 3. Kollberg, H., Avian antibodies (IgY) to fight antibiotic resistance. Clinical Microbiology: Open Access, 2015. 4(2). 4. Sui, J., L. Cao, and H. Lin, Antibacterial activity of egg yolk antibody (IgY) against Listeria monocytogenes and preliminary evaluation of its potential for food preservation. J Sci Food Agric, 2011. 91(11): p. 1946-50. 5. Lee, E.N., et al., In vitro studies of chicken egg yolk antibody (IgY) against Salmonella enteritidis and Salmonella typhimurium. Poult Sci, 2002. 81(5): p. 632-41. 6. Boziaris, I.S. and F.F. Parlapani, Specific spoilage organisms (SSOs) in fish, in The microbiological quality of food. 2017, Elsevier. p. 61-98. 7. Nychas, G.J., et al., Meat spoilage during distribution. Meat Sci, 2008. 78(1-2): p. 77-89. 8. Wang, G.Y., et al., Evaluation of the spoilage potential of bacteria isolated from chilled chicken in vitro and in situ. Food Microbiol, 2017. 63: p. 139-146.

Claims

1. a polymer film having a surface; and an antimicrobial agent chemically bonded to said surface; Including, the antibacterial agent comprises immunoglobulin Y (IgY); Packaging film.

2. The film of claim 1 , further comprising a hydrogel layer disposed on said surface, said hydrogel layer comprising said antimicrobial agent.

3. The film of claim 2 , wherein the hydrogel layer comprises a natural, naturally derived, or synthetic polymer.

4. 4. The film of claim 3, wherein the hydrogel layer comprises a polymer selected from the group consisting of dextran, cellulose, cellulose derivatives (e.g., carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate phthalate), hyaluronic acid, chitosan, gelatin, starch, pectin, alginate, polyacrylamide, polyacrylic acid, polymethyl methacrylate, polylactic acid, polyvinylpyrrolidone, poly (2-hydroxyethyl methacrylate), and combinations thereof.

5. 5. The film of claim 1, wherein the antimicrobial agent is selected from the group consisting of antimicrobial compounds, antimicrobial peptides, antimicrobial proteins, antimicrobial enzymes, antimicrobial polymers, and antimicrobial essential oils.

6. The film of any one of claims 1 to 5, wherein the antimicrobial agent is selected from the group consisting of immunoglobulin Y (IgY), chitosan, and combinations thereof.

7. The film of any one of claims 1 to 6, wherein the antimicrobial agent comprises immunoglobulin Y (IgY) and chitosan.

8. 8. The film of claim 7, wherein IgY and chitosan are each bound to the surface independently of one another.

9. 8. The film of claim 7, wherein IgY is bound to chitosan and chitosan is bound to the surface.

10. 8. The film of claim 7, wherein chitosan is bound to IgY and IgY is bound to the surface.

11. The film according to any one of claims 1 to 10, wherein the IgY is IgY against bacteria, viruses, or fungi.

12. 12. The film of claim 11, wherein the virus is selected from the group consisting of SARS-associated coronavirus, SARS-CoV, SARS-CoV-2, influenza A, influenza A H1N1, influenza A H3N2, influenza B Victoria lineage, and influenza B Yamagata lineage.

13. 12. The film of claim 11, wherein the bacteria is spoilage or contamination bacteria.

14. 14. The film of claim 13, wherein the spoilage bacteria are selected from the group consisting of Escherichia coli, Shewanella putrefaciens, Pseudomonas fluorescens, Photobacterium phosphoreum, Listeria monocytogenes, lactic acid bacteria, and Clostridium botulinum.

15. 15. The film of claim 14, wherein the spoilage bacteria is E. coli.

16. 16. The film of claim 15, wherein the IgY to E. coli is isolated from chicken egg yolk produced in chickens immunized with whole inactivated E. coli.

17. The film of any one of claims 1 to 16, wherein the antimicrobial agent is chemically bound to the surface by a covalent bond.

18. 20. The film of claim 17, wherein the antimicrobial agent is chemically bonded to the surface by an amide bond.

19. 19. The film of any one of claims 1 to 18, wherein the polymer film comprises a polymer selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof.

20. 20. The film of claim 19, wherein the polymer is PBAT.

21. The film of any one of claims 1 to 20, wherein the film is substantially free of inorganic components.

22. The film of any one of claims 1 to 20, wherein the film is completely free of inorganic components.

23. The film of any one of claims 1 to 22, wherein the film is completely free of antibiotics.

24. The film of any one of claims 1 to 23, wherein the film is compostable.

25. The film of any one of claims 1 to 24, used in a packaging product selected from the group consisting of films, trays, and solid substrates.

26. (e) providing a polymeric film having a surface; (f) modifying the surface by ultraviolet, plasma or corona treatment; and (g) chemically bonding an antimicrobial agent to the modified surface; Including, A method of making a packaging film, wherein the antimicrobial agent comprises immunoglobulin Y (IgY).

27. 27. The method of claim 26, wherein (c) further comprises chemically bonding a hydrogel layer to the modified surface.

28. 27. The method of claim 26, further comprising forming a polymer into the polymer film before step (a).

29. 30. The method of claim 28, wherein forming the polymer into the polymer film comprises extruding a polymer resin into the polymer film by film blowing or film casting.

30. 30. The method of any one of claims 26-29, wherein the polymer is selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulosic materials, polyglycolic acid, polycaprolactone, polyvinyl alcohol, carbohydrate-based materials, protein-based materials, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and combinations thereof.

31. 31. The method of claim 30, wherein the polymer is PBAT.

32. The method of any one of claims 26 to 31, wherein the polymer film has a thickness of about 10 to about 500 μm.

33. The method of any one of claims 26 to 31, wherein the polymer film has a thickness of about 80 μm.

34. A method according to any one of claims 26 to 33, wherein step (b) comprises treating the surface in a plasma chamber in the presence of oxygen.

35. 35. The method of claim 34, wherein in step (b), the plasma chamber is from about 5 to about 1000 watts.

36. 36. The method of claim 34 or 35, wherein in step (b), the plasma chamber is at about 250 to about 760 mTorr.

37. 37. The method of any one of claims 34 to 36, wherein step (b) is carried out for about 100 milliseconds to about 10 minutes.

38. 38. The method of any one of claims 34 to 37, wherein step (b) further comprises treating the surface with a solution after the UV, plasma or corona treatment.

39. 39. The method of claim 38, wherein the solution comprises a carboxylic acid.

40. 40. The method of claim 39, wherein the carboxylic acid is selected from the group consisting of formic acid, acetic acid, chloroacetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, fumaric acid, malic acid, acrylic acid, citric acid, gluconic acid, itaconic acid, adipic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, keto acids, aspartic acid, glutamic acid, sodium acetate, potassium acetate, ammonium acetate, vinyl acetate, and combinations thereof.

41. 41. The method of any one of claims 38 to 40, wherein the solution is about 5% to about 99% acetic acid in water.

42. 41. The method of any one of claims 38 to 40, wherein the solution is 100% (glacial) acetic acid.

43. 43. The method of any one of claims 38 to 42, wherein step (b) further comprises rinsing the surface with water after treating the surface with the solution.

44. 44. The method of any one of claims 26 to 43, wherein step (c) comprises cross-linking the antimicrobial agent to the modified surface in the presence of a cross-linking agent.

45. 45. The method of claim 44, wherein the cross-linking agent comprises 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS).

46. 46. ​​The method of claim 45, wherein step (c) comprises treating the modified surface with the antimicrobial agent, EDC, and NHS in an aqueous solution.

47. 47. The method of any one of claims 44 to 46, wherein step (c) is carried out at about 20 to about 60°C.

48. 48. The method of any one of claims 44 to 47, wherein step (c) is carried out for about 100 milliseconds to about 1 hour.

49. 49. The method of any one of claims 44-48, further comprising: (h) washing the film with water to remove unreacted crosslinking agent and unbound antimicrobial agent.

50. 50. The method of any one of claims 26 to 49, wherein the hydrogel layer comprises a natural, naturally derived, or synthetic polymer.

51. 51. The method of claim 50, wherein the hydrogel layer comprises a polymer selected from the group consisting of dextran, cellulose, cellulose derivatives (e.g., carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose hydroxypropyl methyl cellulose, cellulose acetate phthalate), hyaluronic acid, chitosan, gelatin, starch, pectin, alginate, polyacrylamide, polyacrylic acid, polymethyl methacrylate, polylactic acid, polyvinylpyrrolidone, poly 2-hydroxyethyl methacrylate, and combinations thereof.

52. 50. The method of any one of claims 26 to 49, wherein the antimicrobial agent is selected from the group consisting of antimicrobial compounds, antimicrobial peptides, antimicrobial proteins, antimicrobial enzymes, antimicrobial polymers, and antimicrobial essential oils.

53. 53. The method of any one of claims 26 to 52, wherein the antimicrobial agent is selected from the group consisting of immunoglobulin Y (IgY), chitosan, and combinations thereof.

54. 54. The method of any one of claims 26 to 53, wherein the antimicrobial agent comprises immunoglobulin Y (IgY) and chitosan.

55. A packaging film produced according to the method of any one of claims 26 to 54.

56. 56. The packaging film of claim 55, which is compostable.

57. 57. Use of a film according to any one of claims 1 to 24, 55 or 56 in packaging for perishable goods.

58. 58. The use of claim 57, wherein the perishable product is selected from the group consisting of food, chemicals, pharmaceuticals, devices, plants, and animal products.

59. 59. The use according to claim 57 or 58, wherein the perishable product is a food product.

60. 60. The use of claim 59, wherein the food product is selected from the group consisting of meat, poultry, pork, fruit, vegetables, or seafood.

61. 61. The use of claim 60, wherein the food product is meat.

62. 61. The use of claim 60, wherein the food product is fish.

63. 63. The use of any one of claims 57 to 62, wherein the surface of the film is configured to contact the surface of the fresh produce.

64. 64. The use of any one of claims 57 to 63, wherein the antimicrobial agent remains substantially bound to the film and does not diffuse into the fresh produce.

65. 65. The use of any one of claims 57 to 64, wherein the packaging inhibits microbial growth on the perishable goods.

66. 66. The use of any one of claims 57 to 65, wherein the packaging inhibits bacterial growth on the perishable goods.

67. The use according to any one of claims 57 to 66, wherein the film is compostable.

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