Antibacterial articles containing polyurethane

Abstract

The present invention provides an antimicrobial article comprising a polyurethane impregnated with a compound of formula (I). AA-AA-AA-XY (I) The present invention also provides a polyurethane impregnated with a compound of formula (I). The present invention also provides compositions comprising at least one organic solvent, a thermoplastic polyurethane and a compound of formula (I), and coatings prepared using such compositions. The present invention also provides a method for producing a polyurethane impregnated with a compound of formula (I), a medical device comprising a polyurethane impregnated with a compound of formula (I), and a medical use of a polyurethane impregnated with a compound of formula (I).

Description

[Technical field]

[0001] The present invention relates generally to the field of antimicrobial articles, such as wound dressings and other articles that may be susceptible to microbial contamination. More specifically, the present invention relates to antimicrobial articles that contain certain antimicrobial compounds. Such articles have medical applications, such as in the fields of wound care and infection control. The present invention also relates to antimicrobial coatings and coating compositions that contain certain antimicrobial compounds. [Background technology]

[0002] The skin plays an important role as a protective barrier against the external environment, for example protecting against bacterial infections, etc. It is important that the integrity of the skin is maintained and, when this is compromised, for example by the presence of a wound, it is important that the skin heals effectively in order to restore its integrity.

[0003] Wound dressings and the like are commonly applied to wounds to protect the wound during the wound healing process and promote wound healing. In the wound healing process, wound dressings that can absorb wound exudate and maintain an appropriate moisture level in the wound are important. An appropriate level of moisture is important for re-epithelialization and tissue remodeling in the wound healing process.

[0004] There are many types of wound dressings, but in many cases (e.g., in the care of exuding wounds), it is important that the wound dressing maintains a moist wound environment conducive to wound healing. Polyurethane dressings are one example of a wound dressing that is often used in this regard. Polyurethane-based dressings (e.g., polyurethane foam dressings) are typically able to absorb wound exudate and maintain an appropriate level of moisture in the wound.

[0005] However, a major problem in the field of wound care is that, despite the application of wound dressings, wounds often become infected by bacteria such as Staphylococcus aureus. Wound healing is typically impaired as a result of infection, often resulting in symptoms such as increased pain, swelling, redness, and in more severe cases, nausea, chills, and fever. In addition to the wound (or wound bed) itself becoming infected, the wound dressing itself is often colonized with microorganisms (typically bacteria). This is of course undesirable, as it results in a "bacteria-rich" environment in and around the wound, impairing the healing process. Other articles, such as other medical devices, are also susceptible to contamination with microorganisms.

[0006] To combat bacterial wound infections, various commercial wound dressings containing antimicrobial agents are available. For example, polyurethane foam dressings impregnated with silver (Ag), a heavy metal, have been developed and are commercially available. + ) can react with many biomolecules, including DNA, amino acids, and compounds with sulfhydryl groups, resulting in cytotoxic effects. An example of a commercially available silver-impregnated polyurethane foam wound dressing is Optifoam® Gentle AG+ (Medline Industries Inc., USA). Summary of the Invention [Problem to be solved by the invention]

[0007] However, although silver-impregnated dressings are useful for some wound infections, the use of heavy metals such as silver as antimicrobial agents has certain drawbacks. For example, being elemental, silver is not biodegradable, and it is well known that accumulation of silver (a heavy metal) is undesirable from an environmental point of view. The use of silver-impregnated dressings may lead to undesirable environmental accumulation of silver (Ag), for example at sites where such dressings are discarded. Furthermore, bacterial infections resistant to treatment with silver have been reported, and therefore silver-impregnated dressings are not antimicrobially effective against such infections.

[0008] Thus, what is needed in the art is an alternative, preferably advantageous, wound dressing (or other article susceptible to microbial contamination) that has the desirable characteristics of other wound dressings (or other articles susceptible to microbial contamination) and further comprises a compound having good antimicrobial activity. Such a dressing (or other article) is useful, for example, in controlling (or preventing) infection (e.g., bacterial infection) in a wound, and preferably keeps itself (i.e., the dressing or article itself) sterile (or "self-sterile") due to the presence of the antimicrobial compound. [Means for solving the problem]

[0009] The inventors have advantageously provided such alternative wound dressings and other antimicrobial articles. For example, the inventors have developed polyurethane wound dressings containing certain short cationic antimicrobial peptides, which leach from the polyurethane dressing and have a superior ability to inhibit bacterial growth. Without wishing to be bound by theory, it is believed that such dressings have many advantages over silver-impregnated polyurethane foam dressings. For example, (i) cationic antimicrobial peptides are biodegradable, so there are no environmental concerns associated with silver-impregnated dressings, and (ii) bacterial resistance to cationic antimicrobial peptides is very rare (as radical changes in lipid membranes, which are the target of such peptides, are unlikely to occur and prevent the cytotoxic effect). The inventors have also advantageously provided polyurethane coatings comprising such short cationic antimicrobial peptides. Such coatings are useful for coating articles (or surfaces) that are exposed (or prone to exposure) to bacterial contamination (e.g., medical devices such as catheters).

[0010] Thus, in one aspect, the present invention provides an antimicrobial article comprising a polyurethane, comprising: The polyurethane provides an antimicrobial article impregnated with a compound of formula (I). AA-AA-AA-XY (I) During the ceremony, In any order, two of the AA (amino acid) moieties are cationic amino acids, preferably lysine or arginine, but may also be histidine or any non-genetically encoded or modified amino acid that has a positive charge at pH 7.0; one of the AA (amino acid) moieties is an amino acid having a large lipophilic R group having 14-27 non-hydrogen atoms and preferably containing two or more, e.g. two or three, optionally fused or linked cyclic groups, which typically contain five or six, preferably six, non-hydrogen atoms (in the case of fused rings, these non-hydrogen atoms may of course be shared); X is a N atom and is a branched or unbranched C1-C alkyl group which may incorporate up to two heteroatoms selected from N, O, and S. 10 may be substituted with alkyl or aryl groups, e.g., methyl, ethyl, or phenyl, but is preferably unsubstituted; Y is selected from the group consisting of R1-R2-R3, R1-R2-R2-R3, R2-R2-R1-R3, R1-R3 and R4; During the ceremony, R1 is C, O, S or N, preferably C; R2 is C; Each of R1 and R2 may be substituted or unsubstituted with a C1-C4 alkyl group, preferably Y is -R1-R2-R3 (with R1 preferably being C), which is preferably unsubstituted, and when Y is -R1-R2-R2-R3 or R2-R2-R1-R3, it is preferred that one or more of R1 and R2 are substituted; R3 is a group containing 1 to 3 cyclic groups each containing 5 or 6 non-hydrogen atoms (preferably all C atoms, but may also include N, O or S), two or more of which may be fused, and one or more of which may be substituted, which substitutions may include, but usually do not include, polar groups, suitable substituents include halogen, preferably bromine or fluorine, and C1 to C4 alkyl groups, R3 incorporates up to 15, preferably 5 to 12 non-hydrogen atoms, most preferably R3 is a phenyl group; R4 is an aliphatic moiety having 2-20 non-hydrogen atoms, preferably these non-hydrogen atoms are carbon atoms, but may incorporate oxygen, nitrogen or sulfur atoms, preferably R4 contains 3-10, most preferably 3-6 non-hydrogen atoms, said aliphatic moiety may be linear, branched or cyclic. When the R4 group contains a cyclic group, it is preferably attached directly to the nitrogen atom of X. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a graph showing the effect of one day topical treatment with Compound 2 against Staphylococcus aureus FDA486 in a mouse skin infection model. The Y-axis shows the number of colony forming units (CFU) and the X-axis shows the type of topical treatment applied to the mice. Compound 2 is also referred to herein as AMC-109. [Diagram 2] 2 is a graph showing the effect of one day topical treatment with Compound 2 against Streptococcus pyogenes in a mouse skin infection model. The Y-axis shows the number of colony forming units (CFU) and the X-axis shows the type of topical treatment applied to the mice. Compound 2 is also referred to herein as AMC-109. [Diagram 3] Figure 3 is a graph showing the effect of one-day topical treatment against S. aureus FDA486 in a mouse skin infection model. Mice were treated at 9 am, 12 noon, and 3 pm. Skin biopsies were taken at 6 pm. Median values ​​are shown. [Figure 4] Figure 4 is a graph showing the effect of one-day topical treatment against Streptococcus pyogenes CS301 in a mouse skin infection model. Mice were treated at 7 am, 10 am, and 1 pm. Skin biopsies were taken at 4 pm. Median values ​​are shown. [Diagram 5] Figure 5 is a graph showing the effect of one-day topical treatment against S. aureus FDA486 in a mouse skin infection model. Mice were treated at 9 am, 12 noon, and 3 pm. Skin biopsies were taken at 6 pm. Median values ​​are shown. [Figure 6A] FIG. 6 shows the zones of inhibition around a dry PU foam dressing impregnated with AMC-109 (A), a wet dressing impregnated with AMC-109 (B), and a control dressing not impregnated with AMC-109 (C). [Figure 6B]FIG. 6 shows the zones of inhibition around a dry PU foam dressing impregnated with AMC-109 (A), a wet dressing impregnated with AMC-109 (B), and a control dressing not impregnated with AMC-109 (C). [Figure 6C] FIG. 6 shows the zones of inhibition around a dry PU foam dressing impregnated with AMC-109 (A), a wet dressing impregnated with AMC-109 (B), and a control dressing not impregnated with AMC-109 (C). [Figure 7] FIG. 7 shows the Tecoflex film (or coating) impregnated with AMC-109 after drying and peeling from the backside. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Preferred compounds incorporate linear or branched R groups, particularly linear or branched alkyl groups including ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl and their isomers, hexyl and their isomers, and the like, with propyl, isopropyl, butyl, and isobutyl being particularly preferred.

[0013] In some embodiments, R4 is an aliphatic moiety (preferably an alkyl group) having 6-16 non-hydrogen atoms, which are preferably carbon atoms, but may incorporate oxygen, nitrogen, or sulfur atoms, and the aliphatic moiety may be linear, branched, or cyclic.

[0014] In some embodiments, R4 is an isopropyl group.

[0015] Among R4 groups that contain cyclic groups, preferred are molecules in which R4 is cyclohexyl or cyclopentyl.

[0016] Suitable non-genetically encoded amino acids and modified amino acids which can provide cationic amino acids include analogs of lysine, arginine, and histidine, such as homolysine, ornithine, diaminobutyric acid, diaminopimelic acid, diaminopropionic acid, and homoarginine, as well as trimethyllysine and trimethylornithine, 4-aminopiperidine-4-carboxylic acid, 4-amino-1-carbamimidoylpiperidine-4-carboxylic acid, and 4-guanidinophenylalanine.

[0017] The large lipophilic R group of AA may contain heteroatoms such as O, N, or S, but typically has no more than one heteroatom, preferably nitrogen. The R group preferably has no more than two polar groups, more preferably has zero or one polar group, and most preferably has no polar groups.

[0018] The compound, which is preferably a peptide, is preferably a compound of formula (II) below: AA1-AA2-AA1-XY (II) During the ceremony, AA1 is a cationic amino acid, preferably lysine or arginine, but may also be histidine or any non-genetically encoded or modified amino acid that is positively charged at pH 7.0; AA2 is an amino acid having a large lipophilic R group having from 14 to 27 non-hydrogen atoms and preferably containing two or more, e.g. two or three, optionally fused or linked cyclic groups which typically contain five or six, preferably six, non-hydrogen atoms; X and Y are as defined above.

[0019] Further preferred compounds include compounds of the following formulae (III) and (IV): AA2-AA1-AA1-XY (III) AA1-AA1-AA2-XY (IV) wherein AA1, AA2, X, and Y are as defined above. Molecules of formula (II) are more preferred.

[0020] Among the above compounds, certain compounds are particularly preferred. In particular, compounds in which the amino acid having a large lipophilic R group, referred to herein for convenience as AA2, is tributyltryptophan (Tbt) or a biphenylalanine derivative such as Phe(4-(2-naphthyl)) [also referred to herein as Bip(4-(2-naphthyl)], Phe(4-(1-naphthyl)) [also referred to herein as Bip(4-(1-naphthyl)], Bip(4-n-Bu), Bip(4-Ph) or Bip(4-T-Bu) are preferred, with Phe(4-(2-naphthyl) and Tbt being most preferred. In some preferred embodiments, the amino acid having a large lipophilic R group is tributyltryptophan (Tbt).

[0021] Another preferred group of compounds are those in which Y is -R1-R2-R3 as defined above, preferably where R1 and R2 are unsubstituted, most preferably where R1 and R2 are both carbon atoms.

[0022] A further preferred group of compounds are those in which -XY together are a -NHCH2CH2Ph ​​group.

[0023] The compounds include all enantiomeric forms, i.e., both D- and L-amino acids, as well as enantiomers resulting from chiral centers in the amino acid R groups and the C-terminal capping group "-XY". The term "amino acid" includes alpha amino acids as well as beta and gamma amino acids, as well as N-substituted glycines, all of which are considered AA units. The molecules of the invention include beta peptides and depsipeptides.

[0024] The most preferred compounds are:

[0025] [ka]

[0026] [ka]

[0027] t-Bu represents a tertiary butyl group. This second compound incorporating the amino acid 2,5,7-tris-tert-butyl-L-tryptophan is the most preferred compound for use in the present invention (also referred to herein as AMC-109). Analogs of this compound incorporating other cationic residues, particularly Lys, in place of Arg are also highly preferred. Analogs incorporating alternative C-terminal capping groups as defined above are also highly preferred.

[0028] A further preferred group of compounds are those in which XY taken together are selected from the group consisting of -NHCH(CH3)2, -NH(CH2)5CH3, -NH(CH2)3CH3, -NH(CH2)2CH3, -NHCH2CH(CH3)2, NHcyclohexyl and NHcyclopentyl, and particularly preferred are those in which -XY is the group NHCH(CH3)2 or NH(CH2)5CH3. An especially preferred group of compounds are those in which -XY taken together are NHCH(CH3)2.

[0029] A preferred compound is one in which AA1 is arginine, AA2 is tributyltryptophan, and -XY together are NHCH(CH3)2.

[0030] Preferably, the compounds used in the present invention are peptides.

[0031] The compounds of formulae (I)-(IV) above may be peptidomimetics, and peptidomimetics of the peptides described and defined herein also represent compounds used according to the present invention. Peptidomimetics are typically characterized by retaining the polarity, three-dimensional size, and functionality (biological activity) of their peptide equivalents, but replacing the peptide bond with a bond that is often more stable. By "stable" we mean more resistant to enzymatic degradation by hydrolases. In general, bonds that replace amide bonds (amide bond surrogates) maintain many of the properties of the amide bond, such as conformation, steric bulk, electrostatic properties, hydrogen bonding potential, etc. A general discussion of techniques for the design and synthesis of peptidomimetics is presented in Chapter 14 of "Drug Design and Development", Krogsgaard, Larsen, Liljefors, and Madsen (eds.), 1996, Horwood Acad. Pub. In the present case, since the molecule is reacting with a membrane and not with a specific active site of an enzyme, some of the problems described with respect to exactly mimicking affinity and potency or substrate function are not relevant, and peptidomimetics can be easily prepared based on a given peptide structure or motif of the required functional groups.Suitable amide bond surrogates include the following groups: N-alkylated (Schmidt, R. et al., Int. J. Peptide Protein Res. 1995, 46, 47), retroinverse amide (Chorev, M and Goodman, M., Acc. Chem. Res. 1993, 26, 266), thioamide (Sherman DB and Spatola, AF, J. Am. Chem. Soc. 1990, 112, 433), thioester, phosphonate, ketomethylene (Hoffman, RV and Kim, HO, J. Org. Chem. 1995, 60, 5107), hydroxymethylene, fluorovinyl (Allmendinger, T. et al., Tetrahydron Lett., 1990, vol. 31, p. 7297), vinyl, methyleneamino (Sasaki, Y. and Abe, J., Chem. Pharm. Bull., 1990, vol. 31, p. 7297). 1997 45, 13), methylenethio (Spatola, AF, Methods Neurosci. 1993, 13, 19), alkanes (Lavielle, S. et al., Int. J. Peptide Protein Res. 1993, 42, 270), and sulfonamides (Luisi, G. et al., Tetrahedron Lett. 1993, 34, 2391).

[0032] The peptidomimetic compounds of the present invention typically have three identifiable subunits that are approximately equivalent in size and function to amino acids (AA units).Therefore, the term "amino acid" may be used herein for convenience to refer to the equivalent subunits of a peptidomimetic compound.Peptidomimetics may also have groups equivalent to the R groups of amino acids, and the descriptions herein of suitable R groups and N-terminal and C-terminal modification groups apply mutatis mutandis to peptidomimetic compounds.

[0033] As described in the above referenced textbooks, peptidomimetics may involve not only the replacement of amide bonds, but also the replacement of larger structural moieties with dipeptidomimetic or tripeptidomimetic structures, in which case mimetic moieties containing peptide bonds, such as azole-derived mimetics, may be used as replacements for dipeptides. However, peptidomimetics with amide bond replacements as described above, and thus peptidomimetic backbones, are preferred.

[0034] Suitable peptidomimetics include reduced peptides in which the amide bonds have been reduced to methylene amines by treatment with a reducing agent, e.g., a hydride reagent such as borane or lithium aluminum hydride. Such reduction has the added advantage of increasing the overall cationic character of the molecule.

[0035] Other peptidomimetics include, for example, peptoids formed by stepwise synthesis of amide-functionalized polyglycines. Some peptidomimetic scaffolds can be easily obtained from their peptide precursors, such as permethylated peptides, and a suitable method is described by Ostresh, JM et al., Proc. Natl. Acad. Sci. USA (1994), vol. 91, pp. 11138-11142. Strongly basic conditions favor N-methylation over O-methylation, resulting in methylation of some or all of the nitrogen atoms in the peptide bonds and the N-terminal nitrogen.

[0036] Preferred peptidomimetic backbones include polyesters, polyamines, and derivatives thereof, as well as substituted alkanes and alkenes.Peptidomimetics preferably have N- and C-termini which may be modified as described herein.

[0037] The compounds (e.g., peptides) used according to the present invention exhibit antimicrobial activity (typically antibacterial activity) and in particular exert their cytotoxic effect by a mechanism that directly affects the membrane, and can be called membrane-active antimicrobial agents. These compounds have bacteriolytic properties, destabilizing or even perforating the cell membrane. This provides a clear therapeutic advantage over drugs that act or interact with protein components of the target cell, such as cell surface receptors. Although mutations can lead to new forms of the target protein and thus to antibiotic resistance, they are much less likely to cause drastic changes in the lipid membrane to prevent the cytotoxic effect. The bacteriolytic effect has the advantage of causing very rapid cell death, thus killing bacteria before they have a chance to grow. Moreover, the molecules may have other useful properties that kill or damage the target microorganism, such as the ability to inhibit protein synthesis, and thus may have multi-target activity. Antimicrobial activity can be easily determined by suitable methods, and those skilled in the art are familiar with such methods, such as those described in the Examples section of this specification.

[0038] The compound used in the present invention can be synthesized by any convenient method.Generally, reactive groups present (e.g., amino group, thiol group, and / or carboxyl group) are protected throughout the synthesis period.Therefore, the final step of synthesis is the deprotection of the protected derivative of the present invention.

[0039] When constructing a peptide it is in principle possible to start either from the C-terminus or from the N-terminus, although the procedure starting from the C-terminus is preferred.

[0040] Methods of peptide synthesis are well known in the art, however, in the present invention it may be particularly convenient to carry out the synthesis on a solid phase support, such supports being well known in the art.

[0041] A wide selection of protecting groups for amino acids is known, and suitable amine protecting groups include carbobenzoxy (also designated Z), t-butoxycarbonyl (also designated Boc), 4-methoxy-2,3,6-trimethylbenzenesulfonyl (Mtr), and 9-fluorenylmethoxycarbonyl (also designated Fmoc). It will be appreciated that when constructing a peptide from the C-terminus, there will be an amine protecting group on the α-amino group of each new residue added, which will need to be selectively removed prior to the next coupling step.

[0042] For example, carboxyl protecting groups that may be employed include readily cleaved ester groups such as benzyl (Bzl), p-nitrobenzyl (ONb), pentachlorophenyl (OPClP), pentafluorophenyl (OPfp), or t-butyl (OtBu) groups, and methyl groups attached to coupling groups on solid supports, e.g., polystyrene.

[0043] Thiol protecting groups include p-methoxybenzyl (Mob), trityl (Trt), and acetamidomethyl (Acm).

[0044] A variety of procedures exist for the removal of amine and carboxyl protecting groups; however, these must be consistent with the synthetic strategy employed. The side-chain protecting groups must be stable to the conditions used to remove the temporary α-amino protecting group prior to the next coupling step.

[0045] Amine protecting groups such as Boc and carboxyl protecting groups such as tBu can be simultaneously removed by acid treatment, for example with trifluoroacetic acid. Thiol protecting groups such as Trt can be selectively removed with an oxidizing agent such as iodine.

[0046] In certain embodiments, a compound (e.g., a peptide) for use in accordance with the present invention is encapsulated (e.g., nanoencapsulated or microencapsulated). Encapsulation of a compound can be thought of as wrapping the compound within a second material (which may be referred to as a matrix or shell) to form a capsule (e.g., a nanocapsule). Those of skill in the art are familiar with methods and materials for encapsulating compounds (e.g., encapsulating peptides) (e.g., nanoencapsulation).

[0047] As noted above, in one embodiment, an antimicrobial article according to the present invention comprises a polyurethane impregnated with a compound of formula (I). Thus, in this respect, the polyurethane can be considered as the substrate (or material) into which the compound of formula (I) is impregnated.

[0048] For the avoidance of doubt, impregnation does not include a covalent bond between the polyurethane and the compound of formula (I). Rather, impregnation is a non-covalent, releasable bond between the polyurethane and the compound of formula (I). Thus, the compound may be considered to be releasably bonded to the polyurethane.

[0049] Thus, the compound of formula (I) is capable of being released (or leached or diffused) from the polyurethane (or polyurethane matrix) in which it is impregnated (e.g. upon contact with moisture, e.g. at a wound site). This is important in the context of the present invention as the compound of formula (I) has antibacterial activity and it is desirable that, in use (e.g. upon contact with a wound), the compound is releasable from the polyurethane of the article to the site where antibacterial activity is required, for example to prevent or treat wound infection.

[0050] Preferably, during use, the polyurethane (or polyurethane matrix) provides a controlled release (i.e., sustained release) of the compound of formula (I). For example, a therapeutically effective amount of the compound may be released for at least 2, 3, 4, or 5 days. In some embodiments, the compound (preferably a therapeutically effective amount of the compound) may be sustained released for at least 6 hours, 12 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 10 days, 12 days, 15 days, 18 days, 20 days, 25 days, or 30 days. In some embodiments, the compound (preferably a therapeutically effective amount of the compound) may be sustained released for 1-5 days, 1-10 days, 1-15 days, 1-18 days, 1-20 days, 1-25 days, or 1-30 days. In some embodiments, the compound (preferably a therapeutically effective amount of the compound) may be sustained-released for 2 to 5 days, 2 to 10 days, 2 to 15 days, 2 to 18 days, 2 to 20 days, 2 to 25 days, or 2 to 30 days. In some embodiments, the compound (preferably a therapeutically effective amount of the compound) may be sustained-released for 5 to 10 days, 5 to 15 days, 5 to 18 days, 5 to 20 days, 5 to 25 days, or 5 to 30 days.

[0051] A therapeutically effective amount will result in the delivery to the local environment of a concentration of compound that exceeds the minimum inhibitory concentration (MIC) of said compound for the target bacteria.

[0052] As mentioned above, during use, preferably there is a sustained release of the compound of formula (I) from the polyurethane (or polyurethane matrix). Thus, preferably, for an antimicrobial article (e.g., medical device) according to the present invention or a coating according to the present invention, during use (e.g., when contacted with water or water vapor or aqueous solution or body fluid), there is a sustained release of the compound of formula (I) from the polyurethane (or polyurethane matrix). For example, for a medical device according to the present invention, during use (e.g., when used in vivo in a subject, or when contacted with a subject (e.g., a wound in a subject), or when implanted in a subject), preferably there is a sustained release of the compound of formula (I) from the polyurethane (or polyurethane matrix).

[0053] The ability of the impregnated compound to be released from the polyurethane can be easily determined by any suitable method, which is familiar to those skilled in the art. For example, an antimicrobial article (or antimicrobial coating) impregnated with a compound according to the present invention can be contacted with an agar plate inoculated with bacteria (e.g., bacteria of the genus Staphylococcus), and after a suitable incubation time (e.g., 16 hours at 37°C), the plate can be examined for a "zone of inhibition" (i.e., a zone of no or inhibited bacterial growth) around the antimicrobial article. The presence of a "zone of inhibition" (e.g., compared to a test with a control article or coating not impregnated with the antimicrobial compound) indicates that the compound can be released from the polyurethane. Exemplary methods are described in the Examples section of this specification. For example, the "extraction" test described in the Examples section of this specification can also be used to evaluate the ability of the impregnated compound to be released from the polyurethane.

[0054] Any polyurethane having suitable physical properties may be used in accordance with the present invention. Typically, of course, the polyurethane should be such that it is capable of releasing the compound of formula (I) in which it is impregnated, as discussed elsewhere herein.

[0055] Alternatively viewed, the compound of formula (I) may be considered to be dispersed (or at least partially dispersed through) (releasably dispersed) throughout said polyurethane (polyurethane matrix).

[0056] In some embodiments, the compound of formula (I) may be homogeneously dispersed (homogeneously and releasably dispersed) throughout said polyurethane (polyurethane matrix).

[0057] Polyurethanes (sometimes conveniently referred to as PUs) are polymers formed by the reaction of an alcohol (e.g., a diol, triol or other polyol) having two or more reactive hydroxyl groups (-OH) per molecule with an isocyanate (e.g., a di- or tri-isocyanate or other polyisocyanate) having two or more reactive isocyanate groups (-NCO) per molecule. The reaction of such an alcohol with an isocyanate results in a urethane linkage in the backbone. Typically, polyurethane polymers are formed by the reaction of a di- or tri-isocyanate with a polyol (e.g., a diol such as polyethylene glycol (PEG) or polytetrahydrofuran). The preferred polyols are diols. The preferred isocyanates are diisocyanates. In some cases, the polyurethanes may further include one or more chain extenders (i.e., one or more chain extenders may be used in the preparation of the PU).

[0058] Many types of polyurethanes are known in the art, and those of skill in the art are familiar with these and methods of making polyurethanes. In particular, antimicrobial articles (e.g., wound dressings) comprising polyurethanes are well known in the art, and those of skill in the art are familiar with such articles and methods of making them.

[0059] In some embodiments, the polyurethane is a polyether polyurethane, such as a polyethylene glycol (PEG)-based polyurethane. Thus, in some embodiments, the polyurethane is a polyurethane formed by the reaction of a polyether alcohol (polyether polyol, preferably a polyether diol) with an isocyanate, such as the reaction of PEG with an isocyanate (preferably a diisocyanate), or the reaction of polytetrahydrofuran with an isocyanate (preferably a diisocyanate).

[0060] In some embodiments, the polyurethane is a PEG-analog based polyurethane. As an example, in some embodiments, the polyurethane is a polytetrahydrofuran (PTHF) based polyurethane. Polytetrahydrofuran may also be called poly(tetramethylene oxide) or poly(tetramethylene ether) glycol or polytetramethylene ether glycol (PTMEG).

[0061] Typically and preferably, in accordance with the present invention, the PU (e.g., thermoplastic polyurethane; TPU) is one that is capable of absorbing water (or other aqueous solutions or body fluids, etc.), or in some embodiments, the PU is capable of taking up water (or other aqueous solutions or body fluids, etc.) or of swelling upon contact with water (or other aqueous solutions or body fluids, etc.).

[0062] Typically, and preferably in accordance with the present invention, the polyol- (preferably diol-) derived moieties (or monomers) or sites) of (or within) the PU (e.g., TPU) are those that enable the PU to absorb water (or other aqueous solutions or body fluids, etc.) Alternatively, in some embodiments, the polyol- (preferably diol-) derived moieties (or monomers or sites) of the PU are capable of taking up water (or other aqueous solutions or body fluids, etc.) or of swelling upon contact with water (or other aqueous solutions or body fluids, etc.).

[0063] Thus, in some embodiments, the PU (e.g., TPU) comprises a polyol- (preferably diol-) derived portion (or monomer or moiety) that allows the PU to absorb (or take up) water (or other aqueous or body fluids, etc.). Such polyol- (preferably diol-) derived portion (or monomer or moiety) is considered to be hydrophilic. The polyol- (preferably diol-) derived portion that allows the PU to absorb (or take up) water (or other aqueous or body fluids, etc.) is sometimes considered to be a "soft domain". The term "soft domain" is used to contrast with a "hard domain" that the PU may also have. The term "hard domain" is typically used in reference to an isocyanate derived portion (or domain or moiety) of a PU. Soft and hard domains are sometimes referred to as soft and hard segments, respectively.

[0064] Without wishing to be bound by theory, when water penetrates the PU (PU matrix), the compound of formula (I) according to the invention impregnated (or dispersed or incorporated therein) in the parts of the PU that are accessible by the water may dissolve and be released.

[0065] Typically and preferably, the polyol according to the present invention is a polymeric polyol (e.g., a polymeric diol). Thus, in some preferred embodiments, the PU (e.g., a TPU) comprises a polymeric polyol- (preferably a polymeric diol-) derived moiety (or monomer or moiety). Alternatively, in some preferred embodiments, the PU (e.g., a TPU) is formed (or synthesized, or produced, or obtained) by reaction of a polymeric polyol (preferably a polymeric diol) with an isocyanate (preferably a diisocyanate). Optionally, a chain extender may also be included. That is, the reaction may further include a chain extender.

[0066] In some embodiments, polyether polyols (preferably polyether diols) are preferred. Thus, in some preferred embodiments, the PU (e.g., TPU) comprises a polyether polyol- (preferably diol-) derived moiety (or monomer or moiety). Alternatively, in some preferred embodiments, the PU (e.g., TPU) is formed (or synthesized, or produced, or obtained) by reaction of a polyether polyol (preferably a polyether diol) with an isocyanate (preferably a diisocyanate). Optionally, a chain extender may also be included; i.e., the reaction may further include a chain extender.

[0067] Without wishing to be bound by theory, it is believed that PUs formed with polyether polyols (preferably polyether diols) are particularly useful in the context of the present invention because they are hydrophilic, allowing the PUs to absorb water, which is believed to be due to the presence of oxygen atoms.

[0068] In some embodiments, PUs containing soft domains derived from (or based on) polyether polyols, preferably polyether diols, are preferred.

[0069] In some preferred embodiments, the polyether polyol according to the invention is a polyether polyol (more specifically a polyether diol) of formula (V):

[0070] [ka]

[0071] wherein "n" is 2, 3, or 4 (preferably 2 or 4); Each of R1 and R2 is independently selected from the group consisting of H or C1-C6 alkyl (preferably each of R1 and R2 is H); "m" is at least 2.

[0072] In some embodiments, "m" is 2 to 500, e.g., 2 to 250, 2 to 100, 2 to 50, 2 to 10, 5 to 500, 5 to 250, 5 to 100, 5 to 50, 5 to 10, 10 to 500, 10 to 250, 10 to 100, or 10 to 50. In some embodiments, "m" is about 5 to 75, 5 to 50, 5 to 40, 5 to 30, or 5 to 20. In some embodiments, "m" is about 10 to 75, 10 to 50, 10 to 40, 10 to 30, or 10 to 20. In some embodiments, "m" is about 15 to 75, 15 to 50, 15 to 40, 15 to 30, or 15 to 20. In some embodiments, "m" is about 20 to 75, 20 to 50, 20 to 40, or 20 to 30. In some embodiments, "m" is about 5 to 150, or about 5 to 140, or about 6 to 150, or about 6 to 140. In some embodiments, "m" is about 15 to 40.

[0073] In some preferred embodiments, "n" is two.

[0074] In some preferred embodiments, "n" is four.

[0075] In some preferred embodiments, "n" is 2 or 4, and each of R1 and R2 is H.

[0076] In some preferred embodiments where "n" is 2 or 4, "m" is one of the ranges of numbers given above.

[0077] In some preferred embodiments, "n" is 2 or 4, each of R1 and R2 is H, and "m" is one of the ranges of numbers listed above.

[0078] In some embodiments, the PU (e.g., TPU) is formed (or synthesized or manufactured) (or formed or synthesized or manufactured) by reaction of a polyether polyol of formula (V) and an isocyanate (preferably a diisocyanate).

[0079] Alternatively, in some embodiments, the PU (e.g., TPU) comprises a polyether polyol- (preferably diol-) derived moiety (or monomer or moiety or domain) of formula (VI):

[0080] [ka]

[0081] wherein each of R1, R2, "n" and "m" are as defined above in relation to formula (V).

[0082] Alternatively, in some embodiments, the PU (e.g., a TPU) comprises a monomer (or moiety) of formula (VI).

[0083] In some embodiments, a polyol according to the present invention (eg, poly(tetramethylene ether) glycol or other polyol according to formula (V)) may have a molecular weight of from about 500 to about 10,000.

[0084] In some embodiments, the PU is formed (is formed) by the reaction of a polyalkylene glycol (e.g., a polyalkylene glycol having the general formula (V) above) with an isocyanate (preferably a diisocyanate) having two or more reactive isocyanate groups, and may optionally also include a chain extender.

[0085] In some embodiments, the isocyanate (preferably diisocyanate) is an aliphatic isocyanate (preferably aliphatic diisocyanate). For example, the aliphatic diisocyanate may be aliphatic hydrogenated 4,4'-methylene diphenyl diisocyanate. Aliphatic hydrogenated 4,4'-methylene diphenyl diisocyanate may also be referred to as dicyclohexylmethane diisocyanate or HMDI.

[0086] In some other embodiments, the isocyanate (preferably a diisocyanate) is an aromatic isocyanate (preferably an aromatic diisocyanate). For example, the aromatic diisocyanate may be aromatic 4,4'-methylene diphenyl diisocyanate.

[0087] In a preferred embodiment, the isocyanate is an aliphatic isocyanate (preferably an aliphatic diisocyanate).

[0088] Thus, in some preferred embodiments, the PU (e.g., TPU) is formed (or synthesized) by the reaction of a polyol (preferably a polyether polyol, e.g., a polyether diol, e.g., according to formula (V) above) with an aliphatic isocyanate (preferably an aliphatic diisocyanate), which may optionally also include a chain extender (e.g., 1,4-butanediol).

[0089] In certain other embodiments, the PU (e.g., TPU) is formed (or synthesized) by the reaction of a polyol (preferably a polyether polyol, e.g., a polyether diol, e.g., according to formula (V) above) with an aromatic isocyanate (preferably an aromatic diisocyanate). Optionally, a chain extender may also be included (e.g., 1,4-butanediol).

[0090] In some embodiments, the PU (e.g., TPU) is formed (or synthesized) (or formed or synthesized) by the reaction of poly(tetramethylene ether) glycol and an aliphatic isocyanate (preferably an aliphatic diisocyanate). In some embodiments, the PU (e.g., TPU) is formed (or synthesized) (or formed or synthesized) by the reaction of poly(tetramethylene ether) glycol (e.g., according to formula (V) above) and dicyclohexylmethane diisocyanate. Optionally, a chain extender may be included (e.g., 1,4-butanediol), i.e., the reaction may further include a chain extender.

[0091] In some embodiments, the PU (e.g., TPU) is formed (or synthesized) (or formed or synthesized) by the reaction of poly(tetramethylene ether) glycol and an aromatic isocyanate (preferably an aromatic diisocyanate). In some embodiments, the PU (e.g., TPU) is formed (or synthesized) (or formed or synthesized) by the reaction of poly(tetramethylene ether) glycol (e.g., according to formula (V) above) and aromatic 4,4'-methylene diphenyl diisocyanate. Optionally, a chain extender may be included (e.g., 1,4 butanediol), i.e., the reaction may further include a chain extender.

[0092] As is evident from the above discussion, in some embodiments, polyether polyols (i.e., PUs based on polyether polyols) are preferred according to the present invention. However, in some other embodiments, polyester polyols (i.e., PUs based on polyester polyols) may be used. Thus, in some embodiments, the PU (e.g., TPU) comprises a polyester polyol- (preferably diol-) derived moiety (or monomer or moiety). Alternatively, in some preferred embodiments, the PU (e.g., TPU) is formed (or synthesized, or produced, or obtained) (or formed, or synthesized, or produced, or obtained) by the reaction of a polyester polyol (preferably a polyester diol) with an isocyanate (preferably a diisocyanate). Preferred isocyanates are described elsewhere herein. Optionally, a chain extender may be included, i.e., the reaction may further include a chain extender.

[0093] As is evident from the above discussion, the polyurethane may further comprise a chain extender (i.e., in addition to the isocyanate and polyol-derived moieties). Those skilled in the art are familiar with chain extenders. Chain extenders are typically low molecular weight (or short chain) diols or diamines that react with isocyanates (e.g., diisocyanates) to increase the polyurethane molecular weight and increase the block length of the hard segments (or hard domains). Chain extenders may be aliphatic or aromatic. Those skilled in the art are familiar with suitable chain extenders, including, for example, 1,4 butanediol (BDO).

[0094] In some embodiments, the polyurethane is a thermoplastic polyurethane. Thermoplastic polyurethane is sometimes referred to by the acronym TPU. In some preferred embodiments, the TPU is a medical grade TPU. In some embodiments, the TPU is an aliphatic TPU. In some embodiments, the TPU is an aliphatic polyether-based TPU. In some embodiments, the TPU is Tecoflex (e.g., Tecoflex EG80A) (Lubrizol Advanced Materials, Inc.) or a TPU similar to Tecoflex (e.g., Tecoflex EG80A) (e.g., having one or more of the characteristics of Tecoflex). In some embodiments, the TPU is an aromatic TPU. In some embodiments, the TPU is an aromatic copolyester-based TPU. In some embodiments, the TPU is an aromatic polycaprolactone copolyester-based TPU. In some embodiments, the TPU is Pearlcoat DIPP119 (Lubrizol Advanced Materials, Inc.) or a TPU similar to Pearlcoat DIPP119 (e.g., having one or more of the characteristics of Pearlcoat DIPP119). In some embodiments, the TPU is an aromatic polyether-based TPU. In some embodiments, the TPU is Estane 58300 (Lubrizol Advanced Materials, Inc.) or a TPU similar to Estane 58300 (e.g., having one or more of the characteristics of Estane 58300).

[0095] In some embodiments, the polyurethane is a polyurethane of the type used in the Biatain® family of products (Coloplast), or Pellethane™ (e.g., Pellethane 80A, Lubrizol Advanced Materials, Inc.), or a polyurethane similar to such polyurethanes (e.g., having one or more characteristics of such polyurethanes).

[0096] Polyurethanes according to the invention may be absorbent, for example water vapour absorbent, for example hygroscopic, capable of absorbing exudates such as wound exudates.

[0097] Absorbent polyurethanes are typically preferred for wound dressings (e.g., wound dressings where absorption of exudate is desired). Absorbent polyurethanes may swell on contact with moisture, such as wound exudate. Thus, the polyurethanes according to the present invention may be hygroscopic. The polyurethanes according to the present invention may be hydrophilic.

[0098] Preferably, the polyurethane according to the present invention is a medical grade polyurethane, and therefore preferably, the polyurethane according to the present invention is biocompatible.

[0099] The polyurethane according to the present invention may be in the form of a polyurethane foam.Thus, in some embodiments, the present invention provides an antimicrobial article comprising a polyurethane foam impregnated with a compound of formula (I) as defined herein.

[0100] The polyurethane foam according to the present invention has an open-cell structure. Thus, said polyurethane foam may be considered as a permeable (or semi-permeable) or porous polyurethane. According to the present invention, such polyurethane foam is impregnated with a compound of formula (I). Such polyurethane foam can release (e.g., by sustained release) the compound of formula (I), for example, when contacted with water vapor (e.g., in a wound, such as an exuding wound). Typically and preferably, the polyurethane foam can also absorb moisture, for example wound exudate.

[0101] Those of skill in the art are familiar with polyurethane foams, including polyurethane foams suitable for antimicrobial articles (e.g., polyurethane foam dressings).

[0102] Any polyurethane foam having suitable physical properties can be used according to the present invention. For example, polyurethane foam having any pore size, density, thickness, moisture vapor transmission rate (MVTR) or absorption capacity can be used. Typically, of course, the physical properties of the polyurethane foam should be such that it is capable of releasing the compound of formula (I) (impregnated therein) and absorbing moisture (e.g. wound exudate) as described herein.

[0103] In some embodiments, the average (e.g., arithmetic mean) pore size diameter in the polyurethane foam is from 10 μm to 1000 μm, for example, from 10 μm to 900 μm, from 10 μm to 800 μm, from 10 μm to 700 μm, from 10 μm to 600 μm, from 10 μm to 500 μm, from 10 μm to 400 μm, from 10 μm to 300 μm, from 10 μm to 200 μm, or from 10 μm to 100 μm. In some embodiments, the average (e.g., arithmetic mean) pore size diameter in the polyurethane foam is from 20 μm to 1000 μm, for example, from 20 μm to 900 μm, from 20 μm to 800 μm, from 20 μm to 700 μm, from 20 μm to 600 μm, from 20 μm to 500 μm, from 20 μm to 400 μm, from 20 μm to 300 μm, from 20 μm to 200 μm, or from 20 μm to 100 μm. In some embodiments, the polyurethane foam has an average (e.g., arithmetic mean) pore size diameter of 100 μm to 1000 μm, such as 100 μm to 900 μm, 100 μm to 800 μm, 100 μm to 700 μm, 100 μm to 600 μm, 100 μm to 500 μm, 100 μm to 400 μm, 100 μm to 300 μm, or 100 μm to 200 μm. In some embodiments, the average pore size diameter of the pores at the polyurethane foam surface is smaller than the average pore size diameter in the polyurethane foam interior. The average (e.g., arithmetic mean) pore size diameter can be obtained by any suitable means, and those skilled in the art are familiar with such methods, such as field emission scanning electron microscopy.

[0104] In some embodiments, the polyurethane foam has uniform (or relatively uniform) pore size. In other embodiments, the polyurethane foam has pores that are non-uniform in size. The pores may be homogeneous (or substantially homogeneous) or non-uniform in morphology.

[0105] In some embodiments, the polyurethane foam has a viscosity of 0.05 g / cm 3 ~0.5g / cm 3 , 0.05g / cm 3 ~0.4g / cm 3 , 0.05g / cm 3 ~0.3g / cm 3, 0.05g / cm 3 ~0.2g / cm 3 or 0.05g / cm 3 ~0.1g / cm 3 In some embodiments, the polyurethane foam has a density of 0.1 g / cm 3 ~0.5g / cm 3 , 0.1g / cm 3 ~0.4g / cm 3 , 0.1g / cm 3 ~0.3g / cm 3 or 0.1g / cm 3 ~0.2g / cm 3 has a density of

[0106] In some embodiments, the polyurethane foam has a thickness of 1 mm to 20 mm, 1 mm to 10 mm, 1 mm to 5 mm, 1 mm to 4 mm, 1 mm to 3 mm, or 1 mm to 2 mm. In some embodiments, the polyurethane foam has a thickness of 2 mm to 20 mm, 2 mm to 10 mm, 2 mm to 5 mm, 2 mm to 4 mm, or 2 mm to 3 mm. In some embodiments, the polyurethane foam has a thickness of 3 mm to 20 mm, 3 mm to 10 mm, 3 mm to 5 mm, or 3 mm to 4 mm. In some embodiments, the polyurethane foam has a thickness of 4 mm to 20 mm, 4 mm to 10 mm, or 4 mm to 5 mm. In some embodiments, the polyurethane foam has a thickness of 5 mm to 20 mm, or 5 mm to 10 mm. The thickness of the foam can be obtained by any suitable means. Those skilled in the art are familiar with such methods, for example, by using a micrometer.

[0107] In some embodiments, the polyurethane foam has a density of 100 to 3000 g / m 2 / day, 100~2000g / m 2 / day, 100~1000g / m 2 / day, or 100-500g / m 2 In some embodiments, the polyurethane foam has a moisture vapor transmission rate (MVTR) of 500 to 3000 g / m 2 / day, or 500-2000g / m 2 / day, or 500-1000g / m 2 The material has a moisture vapor transmission rate (MVTR) of 100 / day. MVTR is a well-known measure of water vapor passing through a substance or material. MVTR can be evaluated by any suitable means, and those skilled in the art are familiar with suitable methods, such as using a thermo-hygrostat.

[0108] In some embodiments, the polyurethane foam has a viscosity of 0.05 g / cm 2 ~5g / cm 2 , 0.05g / cm 2 ~2g / cm 2 , 0.05g / cm 2 ~1g / cm 2 In some embodiments, the polyurethane foam has an absorption capacity (liquid or water vapor absorption capacity, e.g., water absorption capacity) of 0.5 g / cm 2 ~5g / cm 2 , 0.5g / cm 2 ~2g / cm 2 , 0.5g / cm 2 ~1g / cm 2 In some embodiments, the polyurethane foam has an absorbent capacity of 1 g / cm 2 ~5g / cm 2 or 1g / cm 2 ~2g / cm 2 The absorbent capacity (g / cm) is determined by any suitable means, and those skilled in the art will be familiar with suitable methods, such as by weighing a sample of the polyurethane foam and recording its weight (W1), then immersing the sample of the polyurethane foam in an excess of deionized water (e.g., at 37°C for 30 minutes), after which the polyurethane foam sample is reweighed and its weight (W2) is recorded. 2 ) = (W2 - W1) g / initial area of ​​the polyurethane foam (cm 2 )

[0109] As discussed above, those of skill in the art are familiar with polyurethane foams, including polyurethane foams suitable for antimicrobial articles for medical applications (e.g., polyurethane foam dressings), and therefore are familiar with methods of making polyurethane foams for use in accordance with the present invention.

[0110] A blowing agent is typically used to produce polyurethane foam. A blowing agent is a substance that can produce (or introduce) cellular structure into materials, such as polymers and plastics, that undergo some degree of hardening or phase change during production, via a foaming process. The blowing agent (which may also be referred to as a "foaming agent") creates pores (or holes), and can therefore facilitate the production of polyurethanes (polyurethane foams) with cellular structure. As an example, polyurethane foams can be produced by adding water (and optionally an excess of isocyanate) during the polyurethane production process, where the water reacts with the isocyanate groups and releases carbon dioxide, which acts as a blowing agent, to produce a foamed structure. Such a foaming reaction can be catalyzed by an amine, such as a tertiary amine. Surfactants (e.g., silicone surfactants) can be used to stabilize the foam cells in the polyurethane foaming process. Other methods for producing polyurethane foams are known and will be familiar to those skilled in the art, and foams produced by any suitable means can be used in accordance with the present invention.

[0111] In some embodiments, polyurethane (PU) foam represents a preferred form of PU, while in other embodiments, the polyurethane is not a polyurethane foam (i.e., a non-foamed polyurethane). PU foam may be preferred when the antimicrobial article is a wound dressing.

[0112] Thus, in some embodiments, the polyurethane is a polyurethane foam.

[0113] In other embodiments, the polyurethane is not foamed (i.e., not in the form of a foam). Non-foamed PU is considered to be hard or relatively hard, for example, compared to PU foam. Non-foamed PU is considered to be hard (or relatively hard), but may still be flexible. Thus, in some embodiments, the PU is hard but flexible.

[0114] In some embodiments, the polyurethane is in the form of a polyurethane sheet, layer, patch, or pad (etc.). Thus, in some embodiments, the antimicrobial article comprises a polyurethane-containing sheet, layer, patch, or pad. The sheet, layer, patch, or pad is impregnated with a compound of formula (I).

[0115] Impregnation of the polyurethane (eg, PU foam or non-foam PU) with the compound of formula (I) can be accomplished by any suitable means.

[0116] For example, impregnation of a polyurethane can be performed by applying a solution of a compound of formula (I) to the polyurethane (or incubating or immersing the polyurethane in a solution of a compound of formula (I)) and then drying the polyurethane. After applying the solution of a compound of formula (I), the polyurethane can swell (to absorb the solution) (or at least the outer / surface layer of the polyurethane can swell). After application (or after swelling, if swelling occurs), the polyurethane is dried. Any suitable solvent for the solution of a compound of formula (I) can be used. In some embodiments, the solution is an aqueous solution of a compound of formula (I). For example, the solvent for the solution of a compound of formula (I) can be water (e.g., distilled water). In other embodiments, the solvent can be or include an organic solvent, for example, ethanol and / or chloroform, or can include a polar aprotic solvent (e.g., as described elsewhere herein). In some embodiments, the solvent is an ethanol / chloroform mixture (e.g., a 2:1 ethanol:chloroform mixture). In some embodiments, the solvent is a polar aprotic solvent (or a polar aprotic organic solvent). Organic solvents (e.g., chloroform:ethanol solvents or polar aprotic solvents as described elsewhere herein) can be particularly useful in connection with non-foamed PU materials.

[0117] Typically, of course, a solution of a compound of formula (I) may be applied to (or incubated with) the polyurethane such that a therapeutically effective (antimicrobially effective) amount of the compound is impregnated into the polyurethane. In some cases, the solution of a compound of formula (I) may be applied to (or incubated with) the polyurethane such that a therapeutically effective (antimicrobially effective) amount of the compound is impregnated into the polyurethane. In some cases, the solution of a compound of formula (I) may be applied to (or incubated with) the polyurethane such that at least 0.1 mg, at least 0.5 mg, at least 1 mg, at least 2 mg, at least 5 mg, at least 10 mg or at least 20 mg of the compound is impregnated into 1 cm of the polyurethane. 2In some cases, the solution of a compound of formula (I) may be applied to the polyurethane such that 0.1 mg to 20 mg, 0.5 mg to 20 mg, 1 mg to 20 mg, 2 mg to 20 mg, 5 mg to 20 mg, 10 mg to 20 mg, 0.1 mg to 10 mg, 0.5 mg to 10 mg, 1 mg to 10 mg, 2 mg to 10 mg, 5 mg to 10 mg, 0.1 mg to 5 mg, 0.5 mg to 5 mg, 1 mg to 5 mg, 2 mg to 5 mg, 0.1 mg to 5 mg, 0.5 mg to 5 mg, 1 mg to 5 mg, 2 mg to 5 mg, 0.1 mg to 2 mg, 0.5 mg to 2 mg, 1 mg to 2 mg, 0.1 mg to 1 mg, or 0.5 mg to 1 mg of the compound is impregnated (or applied) per cm of the polyurethane. 2 Optionally, the solution of the compound of formula (I) may be applied to the polyurethane such that 0.5 mg of the compound is impregnated (or applied) per cm of the polyurethane. 2 The polyurethane may be applied so as to be impregnated (or applied) thereto.

[0118] In some cases, the solution of the compound of formula (I) contains at least 0.05 mg, at least 0.1 mg, at least 0.5 mg, at least 1 mg, at least 2 mg, at least 5 mg, at least 10 mg, at least 20 mg, at least 40 mg, at least 50 mg, at least 100 mg, or at least 200 mg of said compound per cm of said polyurethane. 2The polyurethane may be applied so as to be impregnated (or applied) thereto. In some cases, the solution of the compound of formula (I) is 0.05-200 mg, 0.1 mg-200 mg, 0.5 mg-200 mg, 1 mg-200 mg, 2 mg-200 mg, 5 mg-200 mg, 10 mg-200 mg, 20 mg-200 mg, 40 mg-200 mg, 50 mg-200 mg, 100 mg-200 mg, 0.05-50 mg, 0.1 mg-50 mg, 0.5 mg-50 mg, 1 mg-50 mg, 2 mg-50 mg, 5 mg-50 mg, 10 mg-50 mg, 20 mg-50 mg, 0.05-10 mg, 0.1 mg-10 mg, 0.5 mg-10 mg, 1 mg-10 mg, 2 mg-10 mg or 5 mg-10 mg of said compound per cm of said polyurethane. 2 Optionally, the solution of a compound of formula (I) may be applied to the polyurethane such that 0.5-10 mg, 0.5-5 mg, 0.5-2 mg, 0.5-1 mg, 1-10 mg, 1-5 mg or 1 mg-2 mg of the compound is impregnated (or applied) per cm of the polyurethane. 2 The polyurethane may be applied so as to be impregnated (or applied) thereto.

[0119] In some embodiments, a polyurethane according to the invention is impregnated (or carried or applied) with a compound in one of the amounts (or concentrations) described above.

[0120] In some embodiments, the solution of compound of formula (I) applied to the polyurethane (which may conveniently be referred to as a swelling agent since the PU may swell as described elsewhere herein) may have a concentration of compound of formula (I) of 0.01% to 10%, 0.05% to 10%, 0.1% to 10%, 0.2% to 10%, 0.25% to 10%, 0.5% to 10%, 10 ... % to 10%, 2% to 10% or 5% to 10%, 0.01% to 5%, 0.05% to 5%, 0.1% to 5%, 0.2% to 5%, 0.25% to 5%, 0.5% to 5%, 1% to 5%, 2% to 5%, 0.01% to 3%, 0.05% to 3%, 0.1% to 3%, 0.2% to 3%, 0.25% to 3%, 0.5% to 3%, 1% to 3%, 2% to 3% (e.g., weight / volume %). In some embodiments, the solution of the compound of formula (I) (the swelling agent) has a concentration of the compound of formula (I) of up to 0.5%, up to 1%, up to 2%, up to 3%, up to 5%, or up to 10% (e.g., weight / volume %). In some embodiments, the solution of the compound of formula (I) (swelling agent) has a concentration of the compound of formula (I) of at least 0.01%, at least 0.05%, at least 0.1%, at least 0.2%, at least 0.25%, at least 0.5%, at least 1%, at least 2%, at least 3%, or at least 5% (e.g., weight / volume %). In some embodiments, the solution of the compound of formula (I) (swelling agent) has a concentration of the compound of formula (I) of about 1%, about 2%, about 3%, about 4%, about 5%, or about 10% (e.g., weight / volume %). As an example, the solution of the compound of formula (I) (swelling agent) may have a concentration of the compound of formula (I) of 2.8% (w / v).

[0121] In some embodiments, impregnation of the compound of formula (I) into the PU foam can be carried out by applying a solution of the compound of formula (I) (e.g., an aqueous solution, e.g., the solvent can be water) to the PU foam (or incubating or immersing the PU foam in such a solution) and then drying the polyurethane. The preferred features of the impregnation method discussed elsewhere herein can be applied to the PU foam.

[0122] In some embodiments, impregnation of a PU that is not in the form of a foam (i.e., a PU that is not a PU foam) with a compound of formula (I) can be performed by applying to the PU (or incubating or immersing the PU in) a solution of a compound of formula (I) (typically a solution in an organic solvent (or two or more organic solvents), e.g., as described elsewhere herein) and then drying the polyurethane. In such embodiments, the PU typically swells upon application of the solution (or incubation with the solution). As described elsewhere herein, the length of application (or incubation) time or swelling time can be selected based on the nature (e.g., thickness) of the PU to be impregnated and / or the desired depth of impregnation of the PU. The preferred features of the impregnation methods discussed elsewhere herein can be applied to PUs that are not in the form of a foam.

[0123] Another method for impregnating polyurethane with the compound of formula (I) is electrospinning. Electrospinning is a well-known voltage-driven process governed by electrohydrodynamic phenomena that can produce fibers (e.g. nanofibers) from a polymer solution. To obtain impregnated polyurethane according to the present invention by electrospinning, a solution (or "spinning solution") containing said polyurethane and the compound of formula (I) is electrospun onto polyurethane fibers impregnated with said compound. As the polyurethane fibers are extruded by electrospinning, the compound of formula (I) associates with said polyurethane fibers and is thus impregnated into the electrospun polyurethane fibers (or textile products, or meshes of PU fibers, or networks of PU fibers, or mats of PU fibers) produced. Electrospinning is well known in the art, and the skilled artisan will be familiar with suitable electrospinning materials and methods.

[0124] In some embodiments, the polyurethane according to the invention is a mesh of polyurethane fibers (or a PU textile product, or a sheet of PU fibers, or a network of PU fibers, or a mat of PU fibers, etc.). In some such embodiments, the polyurethane fibers (or a mesh or mat of PU fibers, etc.) are produced by electrospinning. In some embodiments, the polyurethane impregnated with a compound of formula (I) is produced by an electrospinning process (e.g., as discussed elsewhere herein).

[0125] Another way to impregnate polyurethane with the compound of formula (I) is to include the compound in the reaction mixture during the preparation of the polyurethane polymer, i.e., to include the compound in the reaction mixture together with the alcohol and isocyanate that react with each other to form polyurethane.For the avoidance of doubt, this does not mean that the compound of formula (I) is covalently bonded to the polyurethane polymer produced.Rather, the compound of formula (I) is associated with the polyurethane produced, and thus impregnated into the polyurethane produced.In some cases, when the compound of formula (I) is included in the reaction mixture during the preparation of the polyurethane polymer, the compound may be included in encapsulated form (e.g., nanoencapsulated form or microencapsulated form).

[0126] Another method of obtaining a polyurethane impregnated with a compound of formula (I) is to prepare a composition (liquid composition or solution or formulation) comprising at least one organic solvent (e.g. at least one polar aprotic solvent), a thermoplastic polyurethane (TPU) and a compound of formula (I), said TPU and compound of formula (I) being dissolved in said at least one organic solvent. Such a composition is conveniently also called a coating composition or paint composition. Such a composition can be used to coat (or paint) an article (or part of an article), and then when the solvent evaporates from the composition (after the article or part thereof has been painted / coated with the solution), said article has a coating (or layer or surface layer or paint) comprising a polyurethane impregnated with a compound of formula (I) (i.e. a coating (or layer or surface layer or paint) is left). Preferred features of the impregnation method discussed elsewhere herein may be applied, where appropriate, to aspects or embodiments of the invention relating to paint (or coating) compositions, paint (or coating) methods, or articles painted (or coated) with paint (or coating) compositions. Preferred features relating to the paint (or coating) composition, the paint (or coating) method, and articles painted (or coated) with the paint (or coating) composition are discussed elsewhere herein in connection with other aspects of the invention. Paint / coating methods according to the present invention can be particularly advantageous as they can easily provide an antimicrobial coating (or layer) to a wide range of articles (or portions thereof) by simply "painting" them with the paint / coating composition of the present invention.

[0127] The antimicrobial article can be any article that is susceptible to microbial (typically bacterial) contamination.

[0128] Typically, the antimicrobial article is a medical device, and thus, in some embodiments, the antimicrobial article is an article suitable for use in preventing or treating an infection (preferably a bacterial infection) in a medical environment.

[0129] In a preferred embodiment, the antimicrobial article is a dressing.

[0130] In preferred embodiments, the antimicrobial article is a wound dressing, a surgical pad, an anti-wound dressing, or the like.

[0131] In a particularly preferred embodiment, the antimicrobial article is a wound dressing.

[0132] In some embodiments, the wound dressing comprises a sheet (or layer or patch or pad) of polyurethane impregnated with a compound of formula (I).

[0133] In some embodiments, the wound dressing may include one or more additional components.

[0134] In some embodiments, the sheet (or layer or patch or pad, etc.) of polyurethane impregnated with a compound of formula (I) may be used in combination with other wound dressing components, such as gauze, bandages, secondary dressings, etc. For example, in some embodiments, a wound dressing may include a sheet (or layer or patch or pad, etc.) of polyurethane impregnated with a compound of formula (I) and one or more additional wound dressing components, such as an additional absorbent layer and / or a secondary layer (or outer layer or cover layer or backing layer), which may act, for example, to secure the wound dressing to the skin. For example, a polyurethane patch impregnated with a compound of formula (I) may be provided with an adhesive backing layer to secure the polyurethane patch to the skin.

[0135] Thus, in some embodiments, the wound dressing may be a multi-component wound dressing (or a multi-layer wound dressing), in which the sheet (or layer or patch or pad etc.) of polyurethane impregnated with a compound of formula (I) may be one component (or layer).

[0136] In some embodiments, the wound dressing comprises a sheet (or layer or patch or pad, etc.) of polyurethane (eg PU foam) impregnated with a compound of formula (I).

[0137] In some embodiments, the wound dressing comprises a sheet (such as a layer or patch or pad) comprising polyurethane (eg, PU foam) impregnated with a compound of formula (I).

[0138] The wound may be a partial thickness wound or a full thickness wound. The wound may be a skin laceration, abrasion, laceration (cut) or burn (e.g., first or second degree burn). The wound may be an incision wound. The wound may be an excision wound. The wound may be a surgical wound.

[0139] Wounds may be acute and chronic. Acute wounds are wounds that progress through the three stages of the healing process (i.e., inflammatory, proliferative, and remodeling) in an orderly manner without prolonged periods. However, chronic wounds are wounds that do not complete the regular sequence of biochemical events because the wound is stuck in one of the healing stages. In other words, chronic wounds are wounds that have not healed for at least 40 days, preferably at least 50 days, more preferably at least 60 days, and most preferably at least 70 days. In some embodiments, chronic wounds are preferred.

[0140] In some embodiments, the wound is an exuding wound (ie, a wound that produces wound exudate or wound fluid).

[0141] The wound to be treated may be, for example, a surgical incision or trauma, e.g., mechanical, thermal, electrical, chemical or radiation trauma; a naturally formed lesion such as a skin ulcer (e.g., a venous ulcer, a diabetic ulcer or a bedsore); a blister (e.g., a friction blister or a fever blister or a blister caused by a pathogen infection such as chickenpox); a tear or slough of tissue caused by anal fissure or stomatitis.

[0142] In other embodiments, the antimicrobial article is not a dressing. The antimicrobial article may be another type of medical device. For example, medical devices include implants and prostheses, including surgical fasteners, catheters (e.g., urinary catheters or central venous catheters), lines, and the like, as well as orthopedic (or joint) implants, such as hip and knee implants, as well as dental implants, pins, stents, cardiac rhythm devices, deep brain stimulators, and intrauterine devices. In some embodiments, "in-dwelling" medical devices are preferred. One particularly preferred type of medical device is a catheter (e.g., a urinary catheter).

[0143] In another aspect, the present invention provides a polyurethane (e.g. a polyurethane foam, or a polyurethane not in the form of a foam (which is considered a solid PU), or a polyurethane (e.g. a TPU) coating) impregnated with a compound of formula (I). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0144] In another aspect, the present invention provides a method for producing a polyurethane impregnated with a compound of formula (I). The method comprises the steps of (i) applying a solution of a compound of formula (I) to the polyurethane (or incubating the polyurethane with a solution of a compound of formula (I)) and (ii) drying the polyurethane to which the solution has been applied, thereby producing a polyurethane impregnated with a compound of formula (I). The application of step (i) may lead to swelling of the polyurethane. Thus, the drying of step (ii) may be drying of the swollen polyurethane obtained after application (or incubation) of the solution in step (i). Drying may be performed at ambient temperature (i.e. passive drying) or alternatively an active drying step may be performed. In some embodiments, drying may be performed at about 20° C. (e.g. for about 12 hours). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention. For example, preferred compounds of formula (I) and preferred amounts or concentrations of compounds of formula (I) in solution are described elsewhere herein. Suitable solvents for the solution of compounds of formula (I) (eg, water or ethanol:chloroform or other organic solvents) are also described elsewhere herein.

[0145] In some embodiments of a method of making a polyurethane impregnated with a compound of Formula (I), comprising applying a solution of a compound of Formula (I) to the polyurethane (or incubating the polyurethane with a solution of Formula (I) (which may swell the polyurethane), the solution may be applied to the polyurethane for 1 minute to 24 hours, 1 minute to 12 hours, 1 minute to 10 hours, 1 minute to 5 hours, 1 minute to 2 hours, 1 minute to 1 hour, 1 minute to 30 minutes, 1 minute to 10 minutes, or 1 minute to 5 minutes. In some embodiments, the solution may be applied to the polyurethane for 3 minutes to 24 hours, 3 minutes to 12 hours, 3 minutes to 10 hours, 3 minutes to 5 hours, 3 minutes to 2 hours, 3 minutes to 1 hour, 3 minutes to 30 minutes, 3 minutes to 10 minutes, or 3 minutes to 5 minutes.

[0146] In some embodiments, the solution may be applied to the polyurethane (or incubated with a solution of Formula (I)) for up to 3 minutes, up to 5 minutes, up to 10 minutes, up to 30 minutes, up to 1 hour, up to 5 hours, up to 10 hours, up to 12 hours, or up to 24 hours. In some embodiments, the solution may be applied to the polyurethane for at least 3 minutes, at least 5 minutes, at least 10 minutes, at least 30 minutes, at least 1 hour, at least 5 hours, at least 10 hours, or at least 12 hours. In some embodiments, the solution may be applied to the polyurethane for about 3 minutes or about 10 hours.

[0147] In some embodiments of the method of making a polyurethane impregnated with a compound of Formula (I), comprising applying a solution of a compound of Formula (I) to the polyurethane (or incubating with a solution of a compound of Formula (I)) and swelling the polyurethane, the solution can be applied to the polyurethane for a time (or swelling time) to achieve at least 5%, at least 10%, at least 15%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% absorption (i.e., swelling of the polyurethane). In some embodiments, the solution can be applied to the polyurethane for a time to achieve up to 5%, up to 10%, up to 15%, up to 20%, up to 30%, up to 40%, up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95%, or up to 100% absorption (i.e., swelling of the polyurethane). In some embodiments, the solution can be applied to the polyurethane for a time to achieve absorption (i.e., swelling of the polyurethane) of 5% to 100%, 10% to 100%, 20% to 100%, 30% to 100%, 40% to 100%, 50% to 100%, 60% to 100%, 70% to 100%, 80% to 100%, 90% to 100%, 5% to 50%, 10% to 50%, 20% to 50%, 30% to 50%, 40% to 50%, 5% to 20%, 10% to 20%, or 15% to 20%. "% Absorption" is the percentage weight gain of the polyurethane after application of the solution of the compound of formula (I) (i.e., after swelling) compared to the weight of the polyurethane before application of the solution of the compound of formula (I) (i.e., before swelling). It is the percentage weight gain of the polyurethane after application of the solution of the compound of formula (I) (i.e., after swelling). Optionally, any solution remaining on the surface of the polyurethane can be superficially dried (e.g., with a cellulose wipe) prior to weighing after application (after swelling).

[0148] The length of application time (swell time) can be selected based on the nature (eg thickness) of the polyurethane being impregnated and / or the depth to which impregnation of the polyurethane is desired.

[0149] In some embodiments, the present invention provides a method for producing a polyurethane foam impregnated with a compound of formula (I). The method includes the steps of (i) applying a solution of a compound of formula (I) to the polyurethane foam (or incubating the polyurethane foam with a solution of formula (I)), and (ii) drying the polyurethane foam to which the solution has been applied, thereby producing a polyurethane foam impregnated with a compound of formula (I). In some such embodiments, the solution may be an aqueous solution (e.g., the solvent may be water), while in other embodiments, the solvent may be an organic solvent. Preferred features of the impregnation method discussed elsewhere herein may be applicable to the method for producing an impregnated PU foam.

[0150] The process of impregnating the PU foam typically results in an impregnated PU foam in which the compound of formula (I) is homogeneously or uniformly (or substantially homogeneously or substantially uniformly) impregnated (or dispersed) throughout the PU foam (i.e., throughout the PU foam matrix).

[0151] In one embodiment, the present invention provides a PU foam impregnated with a compound of formula (I), wherein the compound of formula (I) is homogeneously or uniformly (or substantially homogeneously or substantially uniformly) impregnated (or dispersed) throughout the PU foam (i.e., throughout the PU foam matrix).

[0152] In one embodiment, the present invention provides a PU foam impregnated with a compound of formula (I) produced by the process for producing an impregnated polyurethane foam according to the present invention.

[0153] In some embodiments, the present invention provides an antimicrobial article (e.g., a wound dressing) comprising a PU foam impregnated with a compound of formula (I) produced by the process for making an impregnated polyurethane foam according to the present invention.

[0154] In some embodiments, the present invention provides a method for producing a polyurethane not in the form of a foam (i.e., a PU that is not a PU foam) impregnated with a compound of formula (I). The method comprises the steps of (i) applying to the PU (or incubating the PU with or soaking the PU with) a solution of a compound of formula (I) (typically a solution in which the solvent is an organic solvent (or two or more organic solvents), e.g. as described elsewhere herein), and (ii) drying the PU to which the solution has been applied, thereby producing a polyurethane impregnated with a compound of formula (I). In such embodiments, the PU (or at least the outer / surface layer of the PU) typically swells upon application (or incubation) of the solution. As described elsewhere herein, the length of application (or incubation) time or swelling time may be selected based on the nature (e.g. thickness) of the PU to be impregnated and / or the desired depth of impregnation of the PU. The preferred features of the impregnation method discussed elsewhere herein may be applied to the method for producing an impregnated PU not in the form of a foam. For example, drying may occur at ambient temperature (ie, passive drying) or alternatively, an active drying step may be performed.

[0155] To achieve swelling of the PU (or at least the outer / surface layer of the PU) that is not in the form of a foam and impregnation of said PU with the compound, a suitable solvent (or combination of solvents) can be used as a solvent in the solution of the compound of formula (I). A person skilled in the art can select a suitable solvent. Typically, said solvent is an organic solvent, for example, alcohol (e.g., ethanol) and / or chloroform can be used (for example, a mixture of alcohol and chloroform, for example, a mixture of ethanol and chloroform can be used). Alternatively, a polar aprotic solvent can be used, for example, as described elsewhere herein.

[0156] Methods of impregnating a PU that is not in the form of a foam typically result in an impregnated PU in which the compound of formula (I) is not homogeneously impregnated or dispersed throughout the PU (i.e., is not homogeneously impregnated or dispersed throughout the PU matrix).

[0157] Without wishing to be bound by theory, when impregnating a PU that is not in the form of a foam (e.g., solid or non-foamed polyurethane), during the swelling process, the outer layer of the polyurethane (i.e., the polyurethane on the surface of the PU substrate, the polyurethane closest to the PU substrate, or the polyurethane towards the surface of the PU substrate) is saturated, while the inner layer (furthest from the surface) is only partially saturated (or not saturated), and a concentration gradient may exist. By stopping the swelling process before reaching full saturation (or impregnation) of the entire polyurethane sample / article, a polyurethane sample / article can be obtained in which the surface / outer layer contains the desired concentration of compound. The inner layer of the polyurethane (i.e., the polyurethane further / furthest from the surface) contains less compound (or no peptide) than the surface / outer layer. In other words, without being bound by theory, by controlling the swelling time, the extent (or depth) of penetration of the swelling agent (and the compound) into the polyurethane can be controlled. Thus, by controlling the swelling time, the impregnation of the polyurethane can be controlled, and if desired, impregnation of only the surface / outer surface of the polyurethane can be achieved. The thickness of the impregnated portion (or layer) can determine the rate at which the compound leaches out and the time it takes for the compound to leach out.

[0158] Thus, in some embodiments, the method of impregnating a PU not in the form of a foam results in a PU in which only the outer layer of the PU (or the surface layer of the PU or PU substrate) is impregnated with a compound of formula (I) and the inner phase of the PU is not impregnated (or is less impregnated). Thus, in some embodiments, the method of impregnating a PU not in the form of a foam can produce a PU impregnated with a compound of formula (I) in which there is a concentration gradient of the compound in the PU, with a higher concentration of the compound in the outer layer of the PU compared to the inner layer of the PU.

[0159] Thus, in some embodiments, the method of impregnating a PU that is not in the form of a foam results in a PU in which the compound according to formula (I) is impregnated into only a portion (or more than a portion) of the total depth (total depth) of the PU being impregnated (PU substrate). Alternatively, in some embodiments, the method of impregnating a PU that is not in the form of a foam results in a PU in which the compound according to formula (I) is impregnated into only a portion (or more than a portion) of the total depth from the surface of the PU being impregnated (PU substrate).

[0160] In some embodiments, the portion of the total depth of the substrate (or the total depth from the surface of the PU) that is impregnated with a compound of formula (I) is < 90%, < 80%, < 70%, < 60%, < 50%, < 40%, < 30%, < 20%, < 10%, < 5% or < 2% of the total depth of the PU. Preferably, at least 1%, at least 2%, at least 5%, at least 10%, at least 20%, at least 30%, at least 40% or at least 50% of the total depth of the PU (or the total depth from the surface of the PU substrate) is impregnated with a compound of formula (I). In some embodiments, 1% to 90%, preferably 1% to 90%, 2% to 90%, 5% to 90%, 10% to 90%, 20% to 90%, 30% to 90%, 40% to 90%, 50% to 90%, 1% to 50%, 2% to 50%, 5% to 50%, 10% to 50%, 20% to 50%, 30% to 50%, 40% to 50%, 1% to 20%, 2% to 20%, 5% to 20%, 10% to 20%, 1% to 10%, 2% to 10%, 5% to 10%, 1% to 5%, or 2% to 5% of the total depth of the PU (or the total depth from the surface of the PU substrate) is impregnated with a compound of Formula (I).

[0161] In some embodiments, the swelling time is selected depending on the nature (e.g., thickness) of the PU to be impregnated and / or the depth to which the PU is desired to be impregnated. In some such embodiments, (i) a short (or shorter) swelling time can be used when the PU to be impregnated is thin (or relatively thin) and / or impregnation of the inner (or deeper) layer(s) of the PU is not desired. Or (ii) a long (or longer) swelling time can be used when the PU is thick (or relatively thick) and / or impregnation of the inner (or deeper) layer(s) of the PU is desired. The appropriate swelling time can be determined by one skilled in the art depending on the desired properties of the impregnated PU.

[0162] In one aspect and in some embodiments, the present invention provides a PU not in the form of a foam impregnated with a compound of formula (I) produced by the process for producing an impregnated polyurethane not in the form of a foam according to the present invention.

[0163] In one aspect and in some embodiments, the invention provides a PU that is not in the form of a foam impregnated with a compound of formula (I), where the PU is non-uniformly or non-homogeneously impregnated with the compound of formula (I). Alternatively, in some aspects and embodiments, the invention provides a PU that is not in the form of a foam impregnated with a compound of formula (I), where the compound is not homogeneously distributed throughout the PU (or the PU matrix). In one aspect, the invention provides a PU that is not in the form of a foam impregnated with a compound of formula (I), where there is a concentration gradient of the compound within the PU (or PU matrix), with a higher concentration in the outer layer(s) of the PU compared to the inner (or deeper) layer(s) of the PU.

[0164] In one aspect and in some embodiments, the present invention provides a PU, not in the form of a foam, impregnated with a compound of formula (I), wherein the compound is impregnated into the PU (PU matrix) at (or beyond) only a portion of the total depth (or only a portion of the total depth from the surface), with preferred depths being described elsewhere herein.

[0165] In some embodiments, the present invention provides an antimicrobial article (e.g., a medical device) comprising (or consisting of) a PU not in the form of a foam impregnated with a compound of formula (I) produced by the process for producing an impregnated polyurethane not in the form of a foam according to the present invention.

[0166] In some embodiments, the present invention provides an antimicrobial article (e.g., a medical device) comprising (or consisting of) a PU that is not in the form of a foam impregnated with a compound of formula (I), the PU being non-uniformly or non-homogeneously impregnated with a compound of formula (I). In some embodiments, the present invention provides an antimicrobial article (e.g., a medical device) comprising (or consisting of) a PU that is not in the form of a foam impregnated with a compound of formula (I), the compound not being homogeneously dispersed throughout the PU (or PU matrix). In some embodiments, the present invention provides an antimicrobial article (e.g., a medical device) comprising (or consisting of) a PU that is not in the form of a foam impregnated with a compound of formula (I), where a higher concentration is found in the outer layer(s) of the PU compared to the inner layer(s) of the PU, and where a concentration gradient of the compound exists in the PU. In some embodiments, the present invention provides an antimicrobial article (e.g., a medical device) comprising (or consisting of) a PU that is not in the form of a foam impregnated with a compound of formula (I), wherein the compound is impregnated into (or beyond) only a portion of the total depth of the PU (or only a portion of the total depth from the surface).

[0167] As described elsewhere herein, the inventors have also provided coating compositions (or coating compositions) that are liquid compositions and comprise at least one (e.g., one or two) organic solvents (e.g., at least one polar aprotic solvent), a thermoplastic polyurethane (TPU) and a compound of formula (I), the TPU and the compound of formula (I) being dissolved in the at least one organic solvent. These compositions can be used to "coat" or "apply" a desired article (e.g., a medical device) or a portion thereof, where the article may or may not itself be formed from polyurethane (i.e., the material of the article to which the coating composition is applied may, but need not, be polyurethane). Once the solvent has evaporated, the surface of the article is left with a coating (or layer or surface layer or applied layer) that comprises (or consists of) a thermoplastic polyurethane impregnated with a compound of formula (I).

[0168] Thus, in one embodiment, the present invention provides a composition (which may be conveniently referred to as a paint or coating composition, or agent, or solution) comprising at least one organic solvent, a thermoplastic polyurethane (TPU), and a compound of formula (I), said TPU and compound of formula (I) (each) being dissolved in the at least one organic solvent (or in said composition).

[0169] Viewed another way, the present invention provides a liquid composition comprising at least one organic solvent, a thermoplastic polyurethane (TPU) and a compound of formula (I).

[0170] In some embodiments, the organic solvent is a polar aprotic solvent. For example, the polar aprotic solvent may be tetrahydrofuran (THF), dichloromethane (DCM), acetone, ethyl acetate, dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP), dimethylformamide, or dimethylacetamide. In some embodiments, tetrahydrofuran (THF), dichloromethane (DCM), acetone, or ethyl acetate is preferred. THF and DCM are preferred. THF is particularly preferred. In some embodiments, the organic solvent is an alcohol (e.g., ethanol) and / or chloroform (e.g., a mixture of an alcohol and chloroform can be used, e.g., a mixture of ethanol and chloroform). In some embodiments, the organic solvent is not dimethylformamide.

[0171] In some embodiments, only one solvent is present in the composition. In some embodiments where only one solvent is present in the composition, the solvent is THF. In other embodiments, two or more different solvents are present (e.g., two different solvents may be present).

[0172] In embodiments in which two or more different solvents (e.g., two different solvents) are present in the composition, the different solvents must be miscible (compatible). Miscible solvent combinations can be readily selected.

[0173] In embodiments in which two or more different solvents (eg, two different solvents) are present in the composition, the combination of solvents is preferably a combination (or miscible combination) of the solvents (or solvent types) described above.

[0174] In some embodiments, the coating composition (or formulation) has only one organic solvent. In other embodiments, two or more different solvents may be present in the coating composition (e.g., two different solvents, e.g., two different organic solvents). In embodiments in which two or more (e.g., two) different solvents (e.g., two or more (e.g., two) different organic solvents) are present in the formulation (or composition), the different solvents (e.g., different organic solvents) must be miscible (i.e., miscible with each other). Thus, in some embodiments in which two or more (e.g., two) different solvents (e.g., two or more (e.g., two) different organic solvents) are present in the composition, the TPU and the compound of formula (I) are soluble in a mixture of the two or more solvents. Miscible solvents may also be said to be "compatible" with each other. As is clear from the discussion elsewhere herein, two or more different solvents may be present in some cases, since the TPU and the compound of formula (I) are each dissolved in a different solvent before being mixed together to produce the coating composition of the present invention. In other cases, the TPU and the compound of formula (I) may each be dissolved in the same solvent before being mixed together to produce the coating composition of the present invention.

[0175] The TPU used in the coating composition must be soluble in at least one organic solvent. Preferred TPUs are described elsewhere herein, and such preferred TPUs can be applied mutatis mutandis to the aspects and embodiments of the present invention relating to the coating composition. For example, the TPU may be an aliphatic TPU, an aromatic TPU, an aliphatic polyether-based TPU, an aromatic polyether-based TPU, or an aromatic polycaprolactone copolyester-based TPU. Preferably, the TPU is a polymeric polyol-based TPU (e.g., as described elsewhere herein). Preferably, the TPU is a medical grade TPU.

[0176] The amount of the compound of formula (I) present in the coating composition of the present invention should be sufficient to provide an antimicrobially effective amount (typically an antimicrobially effective amount) of said compound in the impregnated PU coating once said coating composition is applied to an article (or surface) and the solvent has evaporated.

[0177] In some embodiments, the concentration or amount (e.g., w / w) of the compound of formula (I) in the coating composition (or solution) of the invention is at least 0.01%, at least 0.05%, at least 0.1%, at least 1%, at least 5%, at least 10%, or at least 20% relative to the concentration or amount of the TPU. In some embodiments, the concentration or amount (e.g., w / w) of the compound of formula (I) in the coating composition of the invention is up to 1%, up to 5%, up to 10%, up to 20%, or up to 50% relative to the concentration or amount of the TPU. In some embodiments, the concentration or amount (e.g., w / w) of the compound of formula (I) in the coating composition of the present invention is 0.01% to 50%, 0.05% to 50%, 0.1% to 50%, 1% to 50%, 2% to 50%, 5% to 50%, 10% to 50%, 20% to 50%, 0.01% to 20%, 0.05% to 20%, 0.1% to 20%, 1% to 20%, 2% to 20%, 5% to 20%, 0.01% to 10%, 0.05% to 10%, 0.1% to 10%, 1% to 10%, 2% to 10%, 0.01% to 5%, 0.05% to 5%, 0.1% to 5%, 1% to 5%, or 2% to 5% relative to the concentration or amount of the TPU. In one exemplary embodiment, the concentration or amount (e.g., w / w) of the compound of formula (I) in the coating composition of the invention is 5% (or about 5%) relative to the concentration or amount of the TPU.

[0178] In some embodiments, the ratio (w / w) of the entity of formula (I) to the TPU in a coating composition (or solution) of the invention is at least 1:10,000, at least 1:2000, at least 1:1000, at least 1:100, at least 1:20, at least 1:10, or at least 1:5. In some embodiments, the ratio (w / w) of the entity of formula (I) to the TPU in a coating composition (or solution) of the invention is at most 1:100, at most 1:20, at most 1:10, at most 1:5, or at most 1:2. In some embodiments, the ratio (w / w) of the product of formula (I) to TPU in the coating composition (or solution) of the present invention is from 1:10,000 to 1:2, from 1:2,000 to 1:2, from 1:1,000 to 1:2, from 1:100 to 1:2, from 1:50 to 1:2, from 1:20 to 1:2, from 1:10 to 1:2, from 1:5 to 1:2, from 1:10,000 to 1:5, from 1:2,000 to 1:5, from 1: between 1,000-1:5, 1:100-1:5, 1:50-1:5, 1:20-1:5, 1:10,000-1:10, 1:2,000-1:10, 1:1,000-1:10, 1:100-1:10, 1:50-1:10, 1:10,000-1:20, 1:2,000-1:20, 1:1,000-1:20, 1:100-1:20, or 1:50-1:20.

[0179] In some embodiments, the concentration (e.g., w / v) of the compound of formula (I) in the coating composition (or solution) of the invention is at least 0.25 mg / ml, at least 0.5 mg / ml, at least 1 mg / ml, at least 1.5 mg / ml, at least 2 mg / ml, at least 3 mg / ml, at least 4 mg / ml, at least 5 mg / ml, at least 10 mg / ml, or at least 20 mg / ml. In some embodiments, the concentration (e.g., w / v) of the compound of formula (I) in the coating composition (or solution) of the invention is at least 1 mg / ml, at least 1.5 mg / ml, or at least 2 mg / ml (e.g., about 1 mg / ml, about 1.5 mg / ml, or about 2 mg / ml). In some embodiments, the concentration (e.g., w / v) of the compound of formula (I) in the coating composition (or solution) of the invention is 0.25 mg / ml to 5 mg / ml, 0.25 mg / ml to 10 mg / ml, or 0.25 mg / ml to 20 mg / ml. In some embodiments, the concentration (e.g., w / v) of the compound of formula (I) in the coating composition (or solution) of the invention is 1 mg / ml to 5 mg / ml, 1 mg / ml to 10 mg / ml, or 1 mg / ml to 20 mg / ml. In some embodiments, the concentration (e.g., w / v) of the compound of formula (I) in the coating composition (or solution) of the invention is 1.5 mg / ml to 5 mg / ml, 1.5 mg / ml to 2 mg / ml, or 1.5 mg / ml to 20 mg / ml. In some embodiments, the concentration (e.g., w / v) of the compound of formula (I) in the coating composition (or solution) of the invention is 2 mg / ml to 5 mg / ml, 2 mg / ml to 10 mg / ml, or 2 mg / ml to 20 mg / ml. In some embodiments, the concentration (e.g., w / v) of the compound of formula (I) in the coating composition (or solution) of the invention is up to 5 mg / ml, up to 10 mg / ml, or up to 20 mg / ml.

[0180] In some embodiments, the composition (painting composition or coating composition) according to the present invention may further comprise one or more release promoters. A release promoter is an agent that enhances (or improves or promotes) the release of the compound of formula (I) from the (resulting) polyurethane coating (or polyurethane coating layer) produced by painting a surface (or device) with a composition according to the present invention. Release promoters include, but are not limited to, polyethylene glycols (e.g., PEG400 or PEG1000).

[0181] In another aspect, the present invention provides a method for producing the composition (coating composition) of the present invention.

[0182] In one embodiment, the present invention provides a method for making a composition (coating composition or painting composition or solution), the method comprising: (i) dissolving a thermoplastic polyurethane (TPU) in an organic solvent; (ii) dissolving a compound of formula (I) in a solvent; (iii) mixing the TPU dissolved in the organic solvent obtained in (i) with the compound of formula (I) dissolved in the solvent obtained in (ii), This produces a composition of the invention. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0183] In step (i), any organic solvent capable of dissolving the TPU can be used, and in step (ii), any solvent capable of dissolving the compound of formula (I) can be used. The solvents used in steps (i) and (ii) must be miscible (or compatible) with each other.

[0184] In some embodiments, the organic solvent in step (i) is a polar aprotic solvent, as described, for example, elsewhere herein in connection with other aspects of the invention. THF and DCM are preferred organic solvents. THF is particularly preferred. In some embodiments, the organic solvent in step (i) is an alcohol (e.g., ethanol) and / or chloroform (e.g., a mixture of alcohol and chloroform may be used, e.g., a mixture of ethanol and chloroform).

[0185] In preferred embodiments, the solvent in step (ii) is an organic solvent, preferably a polar aprotic solvent (e.g., THF), e.g., as described elsewhere herein in connection with other aspects of the invention. In some embodiments, the solvent in step (ii) is an alcohol (e.g., ethanol) and / or chloroform (e.g., a mixture of an alcohol and chloroform may be used, e.g., a mixture of ethanol and chloroform). In some embodiments, the solvent in step (ii) is chloroform.

[0186] In some embodiments, the solvent in step (i) (i.e., the solvent used to dissolve the TPU) is different from the solvent in step (ii) (i.e., the solvent used to dissolve the compound of Formula (I)).

[0187] In some embodiments, the organic solvent in step (i) (i.e., the solvent used to dissolve the TPU) is the same as the solvent in step (ii) (i.e., the solvent used to dissolve the compound of formula (I). In some such embodiments, the solvent used in steps (i) and (ii) is a polar aprotic solvent, preferably THF.

[0188] The dissolving step (i) may be carried out for any suitable length of time to dissolve the TPU. For example, the dissolving step (i) may be carried out for at least 1 hour, at least 2 hours, at least 5 hours, at least 12 hours, at least 24 hours, at least 48 hours, at least 72 hours, or at least 92 hours. If a given TPU has not dissolved over a given time, it may dissolve over further time. The dissolution of the TPU may be (or is) assessed by any suitable means, including, for example, by visual inspection. The dissolved TPU obtained in step (i) may be viscous or flowable (or non-viscous).

[0189] Dissolving step (ii) can be carried out for any suitable time to dissolve the compound. For example, dissolving step (ii) can be carried out for at least 1 hour, at least 2 hours, at least 5 hours, at least 12 hours or at least 24 hours. If the compound of formula (I) has not dissolved after a certain time, it may dissolve after further time. Dissolution of the compound can be (or is) evaluated by any suitable means, including, for example, by visual inspection.

[0190] The mixing step (iii) may be carried out by any suitable means, for example by mechanical stirring or shaking.

[0191] The dissolving steps (i) and (ii) and the mixing step (iii) may be carried out at any suitable temperature, for example ambient temperature.

[0192] In another aspect, the invention provides a method of making a coating composition (or solution) of the invention, the method comprising the steps of: (i) providing a first solution comprising a thermoplastic polyurethane (TPU) in an organic solvent; (ii) providing a second solution comprising a compound of formula (I), the second solution being miscible with the first solution; and (iii) mixing the first and second solutions. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0193] In another aspect, the present invention provides a method for preparing a composition (coating or painting composition or solution), said method comprising dissolving a thermoplastic polyurethane (TPU) and a compound of formula (I) in an organic solvent and optionally mixing the resulting solutions. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0194] In another aspect, the invention provides a composition produced by the process for producing a composition of the invention.

[0195] In another aspect, the present invention provides use of a coating composition of the present invention to coat an article (or at least a portion of an article) or surface, such as an article (such as a medical device) or surface that is susceptible to microbial (e.g. bacterial) contamination or colonization.

[0196] In another aspect, the present invention also provides a coating (or dry coating or coating material or paint layer) for an article (e.g., a medical device) or surface susceptible to microbial contamination, wherein said coating comprises a TPU impregnated with a compound of formula (I). Preferably, such a coating is produced or formed by applying a coating composition of the present invention to an article or surface and evaporating (drying) said solvent from the applied composition, thereby resulting in a coating (dry coating). Evaporation (or drying) may be carried out at ambient temperature (i.e., passive drying) or alternatively, an active evaporation (or drying) step may be carried out. Evaporation may be carried out for any suitable period of time (e.g., about 2 hours, 5 hours, 12 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days or 7 days) (or longer). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0197] In some embodiments, at least 0.01%, at least 0.05%, at least 0.1%, at least 1%, at least 5%, at least 10%, or at least 20% of the total mass of the coating (or paint layer) is provided by the compound of formula (I). In some embodiments, up to 5%, up to 10%, up to 20%, or up to 50% of the total mass of the coating (or paint layer) is provided by the compound of formula (I). In some embodiments, 0.01% to 50%, 0.05% to 50%, 0.1% to 50%, 1% to 50%, 2% to 50%, 5% to 50%, 10% to 50%, 20% to 50%, 0.01% to 20%, 0.05% to 20%, 0.1% to 20%, 1% to 20%, 2% to 20%, 5% to 20%, 0.01% to 10%, 0.05% to 10%, 0.1% to 10%, 1% to 10%, 2% to 10%, 5% to 10%, 0.01% to 5%, 0.05% to 5%, 0.1% to 5%, 1% to 5%, 2% to 5% of the total mass of the coating (or paint layer) is provided by a compound of Formula (I).

[0198] In some embodiments, the coating (or dry coating or paint layer) has a thickness of at least 1 μm, at least 5 μm, at least 10 μm, at least 20 μm, at least 50 μm, at least 100 μm, or at least 500 μm. In some embodiments, the coating (or dry coating or paint layer) has a thickness of at most 5 μm, at most 10 μm, at most 20 μm, at most 50 μm, at most 100 μm, at most 500 μm, or at most 1000 μm. In some embodiments, the coating (or dry coating or paint layer) has a thickness of about 1 μm to about 5 μm, about 1 μm to about 10 μm, about 1 μm to about 20 μm, about 1 μm to about 50 μm, about 1 μm to about 100 μm, about 1 μm to about 500 μm, or about 1 μm to about 1000 μm. In some embodiments, the coating (or dry coating or paint layer) has a thickness of about 5 μm to about 10 μm, about 5 μm to about 20 μm, about 5 μm to about 50 μm, about 5 μm to about 100 μm, about 5 μm to about 500 μm, or about 5 μm to about 1000 μm. In some embodiments, the coating (or dry coating or paint layer) has a thickness of about 10 μm to about 20 μm, about 10 μm to about 50 μm, about 10 μm to about 100 μm, about 10 μm to about 500 μm, or about 10 μm to about 1000 μm. In some embodiments, the coating (or dry coating or paint layer) has a thickness of about 20 μm to about 50 μm, about 20 μm to about 100 μm, about 20 μm to about 500 μm, or about 20 μm to about 1000 μm. The thickness may be an average (e.g., arithmetic mean) thickness. In some embodiments, the coating may have a uniform or substantially uniform (or homogeneous or substantially homogeneous) thickness. In other embodiments, the coating may have a non-uniform (or non-homogeneous) thickness.

[0199] In one aspect, the invention provides a method of producing a coating for an article or surface susceptible to microbial contamination, said method comprising the steps of (i) applying a composition (or coating or coating composition) of the invention to said article or surface, and (ii) evaporating (or drying) said solvent from the applied composition. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0200] In another aspect, the invention provides a method for producing an article (e.g., a medical device) or surface having an antimicrobial coating comprising a thermoplastic polyurethane impregnated with a compound of formula (I). The method comprises the steps of: (i) preparing a coating composition of the invention; and (ii) applying the composition to the article or surface, or at least a portion of the article or surface (e.g., by immersing the article in the composition or by painting (e.g., spraying) the composition onto the article). Typically, of course, the solvent(s) in the coating composition are then removed by evaporation (or drying). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0201] Particularly preferred are medical devices (eg, catheters or other medical devices described herein) having an antimicrobial coating of a thermoplastic polyurethane impregnated with a compound of formula (I).

[0202] A further aspect of the invention is an article (typically an article susceptible to microbial contamination), preferably a medical device, coated (including partially coated) with a coating composition of the invention as defined herein or a coating of the invention as defined herein (e.g. a dry coating). A further aspect of the invention is an article, preferably a medical device, coated (including partially coated) with a coating composition of the invention as defined herein. Typically, of course, the solvent(s) in the coating composition have been evaporated (or dried) off or have been evaporated (or dried) off. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0203] In a further aspect of the invention, the invention provides a coating composition of the invention as defined herein applied to an article, preferably a medical device.

[0204] In a further aspect, and in some embodiments, the invention provides an antimicrobial article (e.g., a medical device) comprising a polyurethane, wherein the polyurethane is impregnated with a compound of formula (I), and wherein the polyurethane impregnated with a compound of formula (I) is in the form of a coating (or surface layer) on the article. Preferably, the coating is formed (or has been formed) by applying a coating composition (or coating composition) of the invention to the article (typically, of course, the solvent in the composition has been evaporated off). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0205] In another aspect, and in some embodiments, the present invention provides an antimicrobial article (e.g., a medical device) coated, or at least partially coated, with a layer (or coating) of a thermoplastic polyurethane impregnated with a compound of formula (I). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0206] In embodiments of the invention relating to coated (or applied) articles (e.g., medical devices) or surfaces, the article or surface (i.e., the underlying article or surface) to which the coating composition is applied (or to which it is applied) may be formed from any material (or any material that can be coated). The material of the article or surface to which the coating composition is applied (or to which it is applied) need not be polyurethane, but in some cases may be polyurethane. For example, in some embodiments, the article or surface may be formed from silicone, e.g., the article may be a silicone medical device, such as a silicone catheter (e.g., a urinary catheter).

[0207] In another aspect, the present invention provides a PU coating impregnated with a compound of formula (I), wherein said PU coating impregnated with said compound is produced by a method of producing a PU coating according to the present invention.

[0208] In some embodiments, the present invention provides an antimicrobial article or surface comprising a PU coating impregnated with a compound of formula (I), wherein the PU coating impregnated with the compound is made by a method of making a PU coating according to the present invention.

[0209] In another aspect, the invention provides a method of producing a polyurethane impregnated with a compound of formula (I). The method comprises the steps of (i) providing a solution (or "spinning solution") comprising a polyurethane and a compound of formula (I), and (ii) subjecting the solution to electrospinning, thereby producing (or extruding) polyurethane fibers impregnated with a compound of formula (I). Optionally, the fibers may be formed into a sheet or mesh or mat (or the like). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0210] In another aspect, the present invention provides a method for producing a polyurethane impregnated with a compound of formula (I), the method comprising the steps of: (i) providing a reaction mixture comprising: (a) an alcohol having two or more reactive hydroxyl groups (-OH) per alcohol molecule (e.g., a diol, triol or other polyol, e.g., a polymeric polyol, as described elsewhere herein; a diol, preferably a polymeric diol), (b) an isocyanate having two or more reactive isocyanate groups (-NCO) per isocyanate molecule (e.g., a di- or tri-isocyanate or polyisocyanate; a diisocyanate is preferred), and (c) a compound of formula (I); and (ii) subjecting the reaction mixture to conditions under which the alcohol of (a) and the isocyanate of (b) react with each other to produce (or form) a polyurethane, thereby producing a polyurethane impregnated with a compound of formula (I). In such a method, the compound of formula (I) may be in an encapsulated form, e.g., as described elsewhere herein.

[0211] In some embodiments, an antimicrobial article according to the present invention comprises a sheet (or layer or patch or pad, etc.) comprising a polyurethane (e.g., a PU foam) impregnated with a compound of formula (I). In such cases, the method of making the polyurethane impregnated with a compound of formula (I) can alternatively be considered as a method of making the antimicrobial article according to the present invention.

[0212] In some other embodiments, the polyurethane (e.g., PU foam) impregnated with a compound of formula (I) is present in a multi-component (e.g., multi-layer or more complex) antimicrobial article. For example, it may represent one layer (or part) of a more complex antimicrobial article. Thus, in another aspect, the invention provides a method of making an antimicrobial article of the invention, the method comprising the steps of (i) providing a polyurethane (e.g., PU foam) impregnated with a compound of formula (I) (e.g., prepared as described herein), and (ii) incorporating (or combining) the impregnated polyurethane into a multi-component (e.g., multi-layer) antimicrobial article (e.g., combining with an additional absorbent layer and / or outer layer (or cover layer or secondary layer or backing layer or backing layer such as an adhesive backing layer)). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0213] A further aspect provides a polyurethane (e.g. a PU foam, or a PU not in the form of a foam (solid PU or non-foamed PU), or a PU coating, such as a TPU coating) impregnated with a compound of formula (I) produced by the process of the invention, or an antimicrobial article comprising such an impregnated polyurethane. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0214] In another aspect (or alternatively), the present invention provides a polyurethane substrate comprising a compound of formula (I) as defined elsewhere herein. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention. For example, the substrate may be comprised in (or provided as a coating or layer on) an antimicrobial article such as a dressing or other medical device, as described elsewhere herein.

[0215] A further aspect of the present specification provides an antimicrobial article of the invention for use in therapy.

[0216] "Therapy" includes both treatment and prophylaxis, i.e., both treatment and prevention.

[0217] In some embodiments, the invention provides an antimicrobial article of the invention for use in treating or preventing an infection in a subject.

[0218] The infection may be at any "physiological" site or surface susceptible to infection, typically a bacterial infection.

[0219] In some preferred embodiments, the infection is a wound infection (e.g., an infection of a wound as described elsewhere herein). Typically, when the infection is a wound infection, the antimicrobial article is a dressing (e.g., a wound dressing).

[0220] In some embodiments, the infection may be a medical device-associated infection (e.g., an "intrinsic" medical device-associated infection). Typically, when an infection is medical device-associated, the antimicrobial article is a medical device. Thus, in some embodiments, the infection is an infection at the site where a medical device is (or has been) implanted (an "intrinsic" device). Such devices include, for example, intrauterine devices, prostheses (e.g., joint prostheses), and catheters (e.g., central venous or urinary catheters). In some embodiments, the infection is an infection at the catheterization site.

[0221] Preferably, the infection is a bacterial infection, for example, a bacterial infection caused by a gram-positive bacterium (e.g., a bacterium of the genus Staphylococcus or a Streptococcus). In some embodiments, the infection is a Staphylococcus aureus infection. In some embodiments, the infection is a Staphylococcus epidermidis infection. In some embodiments, the infection is an infection caused by a gram-negative bacterium (e.g., a bacterium of the genus Escherichia). In some embodiments, the infection is an infection caused by Escherichia coli.

[0222] A further aspect of the invention provides a polyurethane impregnated with a compound of formula (I) for use in inhibiting bacterial growth, such as bacterial growth in a wound of a subject. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0223] A further aspect of the invention provides a polyurethane impregnated with a compound of formula (I) for use in therapy, preferably for use in the treatment or prevention of an infection in a subject. In some embodiments, the polyurethane impregnated with a compound of formula (I) is administered (or applied) to a subject in the form of an antimicrobial article (e.g., a wound dressing or other medical device). The embodiments of other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0224] A further aspect of the invention provides a compound of formula (I) for use in therapy, preferably a compound of formula (I) for use in the treatment or prevention of an infection in a subject, wherein the compound is administered (or applied) to the subject in the form of a polyurethane impregnated with the compound, or in the form of an antimicrobial article (e.g. a wound dressing or other medical device) comprising a polyurethane so impregnated. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0225] A further aspect of the invention provides the use of a compound of formula (I) for use in therapy, preferably for use in the treatment or prophylaxis of an infection in a subject, wherein said compound is administered (or applied) to the subject in the form of a polyurethane coating impregnated with said compound, or in the form of an antimicrobial article (e.g. a medical device) comprising a polyurethane so impregnated. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0226] Alternatively, the invention provides a method of treating or preventing an infection, the method comprising applying (or administering) to a subject in need thereof (e.g., to a wound in a subject in need thereof) an antimicrobial article according to the invention. The embodiments of other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0227] Viewed alternatively, the present invention provides a method of treating or preventing an infection, the method comprising administering to a subject in need thereof a therapeutically effective amount of a polyurethane impregnated with a compound of formula (I). In some embodiments, the polyurethane impregnated with a compound of formula (I) is administered to the subject in the form of an antimicrobial article (e.g., a wound dressing or other medical device). The embodiments of other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0228] Alternatively, the present invention provides a method of treating or preventing an infection, the method comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula (I), wherein the compound is administered to the subject in the form of a polyurethane impregnated with the compound, or in the form of an antimicrobial article (e.g. a wound dressing or other medical device) comprising such an impregnated polyurethane. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0229] Alternatively, the present invention provides a method of treating or preventing an infection, said method comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula (I), wherein said compound is administered to the subject in the form of a polyurethane coating impregnated with said compound, or in the form of an antimicrobial article (e.g. a medical device) comprising such an impregnated polyurethane coating. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0230] Therapeutically effective amounts can be determined based on clinical evaluations and can be readily monitored.

[0231] Viewed in yet another aspect, the present invention provides the use of a polyurethane impregnated with a compound of formula (I) as defined herein in the manufacture of an antimicrobial article (or medicament) for use in therapy. A preferred therapy is the treatment or prevention of an infection, as described elsewhere in the specification. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0232] The invention also provides the use of a polyurethane impregnated with a compound of formula (I) to inhibit (or prevent) bacterial colonization of an article (e.g. a medical device) or surface, wherein said article or surface comprises said impregnated polyurethane. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0233] The present invention also provides a polyurethane impregnated with a compound of formula (I) for use in inhibiting (or preventing) bacterial colonization of a medical device applied (or implanted) in a subject, wherein said medical device comprises said impregnated polyurethane. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0234] The present invention also provides a compound of formula (I) for use in inhibiting (or preventing) bacterial colonization of a medical device applied (or implanted) in a subject, said medical device comprising a polyurethane impregnated with said compound. The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0235] The invention also provides a method of inhibiting (or preventing) bacterial colonization of an article (e.g. a medical device) or surface, said method comprising providing said article or surface with a polyurethane impregnated with a compound of formula (I). The embodiments of the other aspects of the invention described herein apply mutatis mutandis to this aspect of the invention.

[0236] The term "subject" or "patient" as used herein includes any mammal, such as humans, and any farm animal, livestock animal, or laboratory animal. Specific examples include mice, rats, pigs, cats, dogs, sheep, rabbits, cows, monkeys, etc. However, preferably, the subject or patient is a human. Thus, the subject or patient to be treated according to the present invention is preferably a human.

[0237] In some embodiments, the subject or patient is one who has an infection (e.g., one who has a wound infection or a medical device associated infection), or one who is suspected of having an infection (e.g., one who is suspected of having a wound infection or a medical device associated infection), or one who is at risk of having (or acquiring) an infection (e.g., one who is at risk of having a wound infection or a medical device associated infection).

[0238] In the therapeutic uses and methods of the invention, the antimicrobial article (e.g., a wound dressing or other medical device) is typically applied (or affixed or secured or attached) to a part of the body of a subject in need of infection prevention or treatment (e.g., a wound). Any suitable means can be used to apply (or secure) the antimicrobial article to the body.

[0239] The invention also provides kits comprising one or more of the antimicrobial articles of the invention. Preferably, the kits are for use in the therapeutic methods and uses described herein. Preferably, the kits include instructions for use of the kit components. Preferably, the kits are for treating or preventing an infection, e.g., as described elsewhere herein, and optionally include instructions for use of the kit components for treating such an infection.

[0240] The terms "a" and "an" are used throughout this application to mean "at least one," "at least a first," "one or more," or "a plurality" of the referenced component or step, unless an upper limit is specifically recited thereafter.

[0241] Additionally, where the terms "comprise," "comprises," "has," or "having," or other equivalent terms are used herein, in some more specific embodiments these terms include the terms "consists of" or "consists essentially of," or other equivalent terms.

[0242] The invention will now be further described with reference to the following non-limiting examples and figures.

[0243] FIG. 1 is a graph showing the effect of one day topical treatment with Compound 2 against Staphylococcus aureus FDA486 in a mouse skin infection model. The Y-axis shows the number of colony forming units (CFU) and the X-axis shows the type of topical treatment applied to the mice. Compound 2 is also referred to herein as AMC-109.

[0244] 2 is a graph showing the effect of one day topical treatment with Compound 2 against Streptococcus pyogenes in a mouse skin infection model. The Y-axis shows the number of colony forming units (CFU) and the X-axis shows the type of topical treatment applied to the mice. Compound 2 is also referred to herein as AMC-109.

[0245] Figure 3 is a graph showing the effect of one-day topical treatment against S. aureus FDA486 in a mouse skin infection model. Mice were treated at 9 am, 12 noon, and 3 pm. Skin biopsies were taken at 6 pm. Median values ​​are shown.

[0246] Figure 4 is a graph showing the effect of one-day topical treatment against Streptococcus pyogenes CS301 in a mouse skin infection model. Mice were treated at 7 am, 10 am, and 1 pm. Skin biopsies were taken at 4 pm. Median values ​​are shown.

[0247] Figure 5 is a graph showing the effect of one-day topical treatment against S. aureus FDA486 in a mouse skin infection model. Mice were treated at 9 am, 12 noon, and 3 pm. Skin biopsies were taken at 6 pm. Median values ​​are shown.

[0248] FIG. 6 shows the zones of inhibition around a dry PU foam dressing impregnated with AMC-109 (A), a wet dressing impregnated with AMC-109 (B), and a control dressing not impregnated with AMC-109 (C).

[0249] FIG. 7 shows the Tecoflex film (or coating) impregnated with AMC-109 after drying and peeling from the backside.

[0250] Working Example [Example 1] [Peptide synthesis] [Chemicals] The protected amino acids Boc-Trp-OH, Boc-Arg-OH, Boc-4-phenyl-Phe and Ac-Arg-OH were purchased from Bachem AG, Boc-4-iodophenylalanine, Boc-3,3-diphenylalanine and Boc-(9-anthryl)alanine were purchased from Aldrich. Benzylamine, 2-phenylethylamine, 3-phenylpropylamine, (R)-2-phenylpropylamine, (S)-2-phenylpropylamine, N,N-methylbenzylamine, N,N-ethylbenzylamine and N,N-dibenzylamine, which form the C-terminus of the peptides, were purchased from Fluka, except for N-ethylbenzylamine, which was purchased from Acros. Diisopropylethylamine (DIPEA), 1-hydroxybenzotriazole (1-HOBt), chlorotripyrrolidinophosphonium hexafluorophosphate (PyCloP), and O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU) were purchased from Fluka. 4-n-Butylphenylboronic acid, 4-t-butylphenylboronic acid, 4-biphenylboronic acid, 2-naphthylboronic acid, triortho-tolylphosphine, benzyl bromide, and palladium acetate were purchased from Aldrich. Solvents were purchased from Merck, Riedel-de Haen, or Aldrich.

[0251] [Preparation of amino acids] Preparation of Boc-2,5,7-tri-tert-butyltryptophan-OH: A mixture of H2N-Trp-OH (1.8 g, 8.8 mmol) and t-BuOH (4,7 g, 63.4 mmol) in trifluoroacetic acid (19 mL) is stirred at 70 °C for 3 h. The volume of the resulting medium brown translucent solution is reduced on a rotary evaporator at room temperature for 30 min, and then triturated by dropwise addition of 60 mL of 7% (by weight) NaHCO3. The resulting grey / white granular solid is then collected by vacuum filtration and vacuum dried at room temperature for 24 h. The product is isolated by crystallization from a near-boiling mixture of 40% ethanol in water. The volume is typically about 20 mL per gram of crude product.

[0252] Initial crystallization from the crude product produces isolated product of 80-83% purity (HPLC) relative to all other materials in the sample and approximately 94-95% purity relative to known TBT analogues. Yields at this stage are in the range of 60-65%.

[0253] Benzylation of Boc-4-iodophenylalanine: Boc-4-iodophenylalanine (1 equiv.) was dissolved in 90% aqueous methanol and neutralized to a slightly alkaline pH (measured by litmus paper) by adding cesium carbonate. The solvent was removed by rotary evaporation and the water remaining in the cesium salt of Boc-4-iodophenylalanine was further reduced by repeated azeotropic distillation with toluene. The resulting dry salt was dissolved in dimethylformamide (DMF), benzyl bromide (1.2 equiv.) was added, and the resulting mixture was stirred for 6-8 h. At the end of the reaction, the DMF was removed under reduced pressure to yield an oil containing the title compound. This oil was dissolved in ethyl acetate, and the resulting solution was washed with equal volumes of citric acid solution (3 times), sodium bicarbonate solution, and brine. The title compound was isolated in 85% yield as a pale yellow oil by flash chromatography eluting with dichloromethane:ethyl acetate (95:5). Crystalline benzyl Boc-4-iodophenylalanine could be obtained by recrystallization from n-heptane.

[0254] General procedure for Suzuki coupling: Benzyl Boc-4-iodophenylalanine (1 equiv.), aryl boronic acid (1.5 equiv.), sodium carbonate (2 equiv.), palladium acetate (0.05 equiv.), and triortho-tolylphosphine (0.1 equiv.) were added to a degassed mixture of dimethoxyethane (6 ml per mmol of benzyl Boc-4-iodophenylalanine) and water (1 ml per mmol of benzyl Boc-4-iodophenylalanine). The reaction mixture was kept under argon and heated to 80 °C for 4-6 h. After cooling to room temperature, the mixture was filtered through a short pad of silica gel and sodium carbonate. The filter cake was further washed with ethyl acetate. The filtrates were combined and the solvent was removed under reduced pressure. The product was isolated by flash chromatography using a mixture of ethyl acetate and n-hexane as eluent.

[0255] Preparation of Boc-Bip(n-Bu)-OBn: The title compound was prepared in 53% yield from 4-n-butylphenylboronic acid using the general Suzuki coupling procedure. Boc-Bip(n-Bu)-OBn was isolated using an 80:20 ethyl acetate:n-hexane eluent.

[0256] Preparation of Boc-Bip(t-Bu)-OBn: The title compound was prepared in 79% yield from 4-t-butylphenylboronic acid using the general Suzuki coupling procedure. Boc-Bip(t-Bu)-OBn was isolated using an 80:20 ethyl acetate:n-hexane eluent.

[0257] Preparation of Boc-Bip(4-Ph)-OBn: The title compound was prepared in 61% yield from 4-biphenylboronic acid using the general procedure for Suzuki coupling. Boc-Bip(4-Ph)-OBn was isolated by recrystallization of the crude product from n-heptane.

[0258] Preparation of Boc-Bip(4-(2-naphthyl))-OBn: The title compound was prepared from 2-naphthylboronic acid in 68% yield using the general procedure for Suzuki coupling. Boc-Bip(4-(2-naphthyl))-OBn was isolated by recrystallization of the crude product from n-heptane.

[0259] Preparation of Boc-Bip(4-(1-naphthyl))-OBn: The title compound was prepared from 2-naphthylboronic acid using the general procedure for Suzuki coupling. Boc-Bip(4-(1-naphthyl))-OBn was isolated by recrystallization of the crude product from n-heptane.

[0260] General procedure for deesterification of benzyl esters: The benzyl ester is dissolved in DMF and hydrogenated for 2 days at ambient pressure using 10% Pd on carbon as catalyst. After completion of the reaction, the catalyst is filtered off and the solvent is removed under reduced pressure. The free acid is isolated by recrystallization from diethyl ether.

[0261] Preparation of Boc-Bip(4-n-Bu)-OH: The title compound was prepared in 61% yield from Boc-Bip(n-Bu)-OBn using the general procedure for deesterification.

[0262] Preparation of Boc-Bip(4-t-Bu)-OH: The title compound was prepared in 65% yield from Boc-Bip(t-Bu)-OBn using the general procedure for deesterification.

[0263] Preparation of Boc-Bip(4-Ph)-OH: The title compound was prepared in 61% yield from Boc-Bip(4-ph)-OBn using the general procedure for deesterification.

[0264] Preparation of Boc-Bip(4-(2-naphthyl))-OH: The title compound was prepared in 68% yield from Boc-Bip(4-(2-naphthyl))-OBn using the general procedure for deesterification.

[0265] Preparation of Boc-Bip(4-(2-naphthyl))-OH: The title compound was prepared in 68% yield from Boc-Bip(4-(2-naphthyl))-OBn using the general procedure for deesterification.

[0266] General procedure for solution-phase peptide synthesis using HBTU: Peptides were prepared in solution by stepwise amino acid coupling using the Boc protection strategy according to the following general procedure. The C-terminal peptide moiety with a free amino group (1 equiv.), Boc-protected amino acid (1.05 equiv.) and 1-hydroxybenzotriazole (1-HOBt) (1.8 equiv.) were dissolved in DMF (2–4 ml per mmol of amino component), followed by the addition of diisopropylethylamine (DIPEA) (4.8 equiv.). The mixture was cooled on ice and O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU) (1.2 equiv.) was added. The reaction mixture was shaken at ambient temperature for 1–2 h. The reaction mixture was diluted with ethyl acetate and washed with citric acid, sodium bicarbonate, and brine. The solvent was removed under vacuum, and the Boc-protected groups of the resulting peptides were deprotected in the dark using 95% TFA or anhydrous methanol solution of acetyl chloride.

[0267] Solution phase amide formation with PyCloP. Synthesis of Boc-Arg-N(CH2Ph)2. A solution of Boc-Arg-OH (1 eq.), NH(CH2Ph)2 (1.1 eq.), and PyCloP (1 eq.) in dry DCM (after filtration through alumina) (2 ml) and DMF (1 ml). The solution was cooled on ice and DIPEA (2 eq.) was added with stirring. The solution was stirred at room temperature for 1 h. The reaction mixture was evaporated, redissolved in ethyl acetate, and washed with citric acid, sodium bicarbonate, and brine. The solvent was removed under vacuum and the Boc protecting group of the resulting peptide was deprotected with 95% TFA in the dark.

[0268] Peptide purification and analysis. Delta-Pak (Waters) C column was used with a mixture of water and acetonitrile (both containing 0.1% TFA) as eluent. 18The peptides were purified using reversed-phase HPLC on an analytical Delta-Pak (Waters) C column (100 Å, 15 μm, 25 × 100 mm). 18 Peptides were analyzed by RP-HPLC using a column (100 Å, 5 μm, 3.9 × 150 mm) and positive ion electrospray mass spectrometry on a VG Quattro quadrupole mass spectrometer (VG Instruments Inc., Altringham, UK).

[0269] [Example 2] In vitro activity of the peptides defined herein Materials and Methods (Antibacterial agent) Pre-weighed vials of Compound 1 and Compound 2 were supplied by Lytix Biopharma AS.

[0270] [Table 1]

[0271] [Cell isolate] The bacterial isolates used in this study were from various sources worldwide and maintained at GR Micro Ltd. as high-density suspensions in a high-protein matrix of undiluted horse serum, frozen at -70°C with minimal subcultures. The bacterial species used and their characteristics are shown in Table 1. They consist of 54 Gram-positive, 33 Gram-negative, and 10 fungal species.

[0272] [Minimum inhibitory concentration (MIC) measurement] MICs were determined using the following microbroth dilution methods for antimicrobial susceptibility testing published by the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS):

[0273] M7-A6, Vol.23, No.2, January 2003, "Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically; Approved Standard-Sixth Edition." M100-S15, Vol.25, No1, January 2005, "Performance Standards for Antimicrobial Susceptibility Testing; Fifteenth Informational Supplement." M11-A6, Vol.24, No.2, "Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria; Approved Standard-Sixth Edition." M27-A2, Vol.22, No.15, "Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts; Approved Standard-Second Edition." M38-A, Vol.22, No.16, "Reference Method for Broth Dilution Antifungal Susceptibility Testing of Filamentous Fungi; Approved Standard."

[0274] MIC evaluation was performed using wet plates containing antibacterial or antifungal drugs prepared by GR Micro.

[0275] Cation-adjusted Mueller-Hinton broth (Oxoid Ltd., Basingstoke, UK and Trek Diagnostic Systems Ltd., East Grinstead, UK) (supplemented with 5% horse hemolysate for Streptococcus spp., Corynebacterium jeikeium, and Listeria monocytogenes) was used for aerobic bacteria, with approximately 10 5 The initial inoculum was expressed as colony forming units (CFU) / mL.

[0276] Haemophilus test medium (Mueller-Hinton broth with 0.5% yeast extract and Haemophilus test medium supplement containing 15 mg / L each of hematin and NAD, all from Oxoid, Basingstoke, UK) was used for Haemophilus influenzae, with approximately 10 5 Inoculated at CFU / mL.

[0277] For anaerobic strains, supplemented Brucella broth (SBB) was used, with an inoculum size of approximately 10 6 The CFU / mL was determined by the SBB, a broth consisting of 1% peptone, 0.5% "Lab-lemco", 1% glucose, and 0.5% sodium chloride supplemented with 5 μg / L hemin and 1 μg / L vitamin K (both from Sigma Aldrich Ltd.).

[0278] MICs for yeast and filamentous fungi were performed in MOPS-buffered RPMI 1640 medium (MOPS buffer was obtained from Sigma-Aldrich and RPMI 1640 was obtained from Invitrogen Ltd., Paisley, Scotland). Yeast inoculation was 7.5 × 10 2 ~4×10 3CFU / mL range, fungal inoculum size was approximately 8 × 10 3 ~1×10 5 It was expressed as CFU / mL.

[0279] All plates containing Mueller-Hinton broth were routinely prepared in advance, frozen at -70°C on the day of preparation, and thawed on the day of use. MICs for fungi, Haemophilus spp., and anaerobes were all determined on plates prepared on the same day.

[0280] To assess whether freezing affected peptide activity, some MIC determinations were repeated using plates containing freshly prepared Mueller-Hinton broth.

[0281] [Control strain] The following control (reference) strains were included in the panel of test strains: Escherichia coli: ATCC25922 Staphylococcus aureus: ATCC29213 Enterococcus faecalis: ATCC29212 Streptococcus pneumoniae: ATCC49619 Pseudomonas aeruginosa:ATCC27853 Candida krusei: ATCC6258

[0282] The following control strains were used in addition to the panel of test strains and, where appropriate, were included to ensure that controls were within range. Haemophilus influenzae: ATCC49247 Candida parapsilosis: ATCC22019 Bacteroides fragilis: ATCC25285 Eggerthella lenta: ATCC43055

[0283] [result] The results are shown in single line listing format in Table 1, and the results for the replicate control strains are shown in Table 2. The results for the control strains are highly reproducible, including data from plates containing frozen or freshly prepared Mueller-Hinton broth. Freezing the plates did not affect the MICs of the other bacterial strains.

[0284] The MIC data obtained are very encouraging and indicate that the peptide has a very broad spectrum of activity.

[0285] [Table 2] TIFF2024523026000007.tif229159TIFF2024523026000008.tif228167TIFF2024523026000009.tif229159

[0286] [Table 3]

[0287] MHB, Mueller-Hinton Broth; HTM, Haemophilus Test Medium; SBB, Supplemented Brucella Broth

[0288] [Example 3] [Stability against trypsin degradation and antibacterial activity] The trypsin resistance and antibacterial activity of the compound of formula AA1-AA2-AA1NHCH2CH2Ph ​​were investigated.

[0289] [Measurement and calculation of peptide half-life] Each peptide was dissolved in 0.1 M NH4HCO3 buffer (pH 6.5) to a final peptide concentration of 1 mg / ml. Trypsin solution was prepared by dissolving 1 mg trypsin in 50 ml 0.1 M NH4HCO3 buffer (pH 8.2). To measure stability, 250 μl of freshly prepared trypsin solution and 250 μl of peptide solution were incubated in 2 ml 0.1 M NH4HCO3 buffer (pH 8.6) at 37 °C on a rocking table. Aliquots of 0.5 ml were sampled at various time intervals, diluted with 0.5 ml water:acetonitrile (60:40 v / v) containing 1% TFA, and analyzed by RP-HPLC as described above. Samples without trypsin taken after 0 and 20 h at 37 °C served as negative controls. The integral of the peak area at 254 nm of samples taken during the first 5 h of the assay was used to determine τ 1 / 2 Peptides that showed no degradation during the first 24 hours were classified as stable.

[0290] [Antibacterial Assay] MIC determinations for Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, and Methicillin-resistant Staphylococcus epidermidis (MRSE) ATCC 27626 were performed by Toslab AS using standard methods. Amsterdam, D. (1996) "Susceptibility testing of antimicrobials in liquid media", in Antibiotics in Laboratory Medicine, 4th ed. (Lorian, V. ed.), pp. 75-78, Williams and Wilkins Co., Baltimore.

[0291] [Table 4]

[0292] a Half-lives were calculated using the Cornell University Medical Calculator. b Minimum inhibitory concentration c Staphylococcus aureus ATCC25923 strain d Methicillin-resistant Staphylococcus aureus ATCC33591 e Methicillin-resistant Staphylococcus epidermidis ATCC27626 f Outside the scope of the definition of compounds of this invention

[0293] [Example 4] [In vivo activity of compound 2] Mice were skin infected with S. aureus or S. pyogenes and then administered a total of three doses at 3-hour intervals. Three hours after the last dose, skin biopsies were taken and the number of colony forming units (CFU) present in the skin samples was determined. The results, expressed as the number of colony forming units per mouse, are shown in Figures 1 and 2.

[0294] In experiment 1 (Figure 1), compound 2 was applied to the skin of mice as part of a cream or gel containing 2% (w / w) compound 2. The same cream or gel without compound 2 was used as a negative control (placebo). It was clearly evident that application of the cream or gel containing compound 2 to the skin of mice reduced the CFU count compared to the negative control, indicating that compound 2 exerted an antibacterial effect against S. aureus. The nature of the carrier, i.e. cream or gel, had no significant effect.

[0295] In experiment 2 (Figure 2), compound 2 was applied as gel at two different concentrations, namely 1% or 2%. A placebo gel and a known antibacterial drug, bactroban, were used as controls. It can be seen that the gel containing compound 2 was more effective at reducing CFU counts than the placebo gel and bactroban. Also, the gel containing 2% compound 2 was more effective than the gel containing only 1% compound 2.

[0296] [Example 5] [Preparation of the compounds used in the present invention and their physical properties, antibacterial properties, and hemolytic properties] Peptide synthesis - related information is also provided in Example 1. [Chemicals] The protected amino acids Boc-Arg-OH and Boc-4-phenyl-Phe were purchased from Bachem, and Boc-4-iodophenylalanine was purchased from Aldrich. Isopropylamine, propylamine, hexylamine, butylamine, hexadecylamine, isobutylamine, cyclohexylamine, and cyclopentylamine, which form the C-terminus of the peptides, were purchased from Fluka. Diisopropylethylamine (DIPEA), 1-hydroxybenzotriazole (1-HOBt), chlorotripyrrolidinophosphonium hexafluorophosphate (PyCloP), and O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBT U) were purchased from Fluka. 4-n-Butylphenylboronic acid, 4-t-butylphenylboronic acid, 4-biphenylboronic acid, 2-naphthylboronic acid, triortho-tolylphosphine, benzyl bromide, and palladium acetate were purchased from Aldrich. Solvents were purchased from Merck, Riedel-de Haan, or Aldrich.

[0297] Preparation of Boc-Phe(4-4'-biphenyl)-OBn: The title compound was prepared in 61% yield from 4-biphenylboronic acid using the general procedure for Suzuki coupling. Boc-Phe(4-4'-biphenyl)-OBn was isolated by recrystallization of the crude product from n-heptane.

[0298] Preparation of Boc-Phe(4-(2'-naphthyl))-OBn: The title compound was prepared in 68% yield from 2-naphthylboronic acid using the general procedure for Suzuki coupling. Boc-Phe(4-(2'-naphthyl))-OBn was isolated by recrystallization of the crude product from n-heptane.

[0299] Preparation of Boc-Phe(4-4'-biphenyl)-OH: The title compound was prepared in 61% yield from Boc-Phe(4-4'-biphenyl)-OBn using the general procedure for deesterification.

[0300] Preparation of Boc-Phe(4-(2'-naphthyl))-OH: The title compound was prepared in 68% yield from Boc-Phe(4-(2-naphthyl))-OBn using the general procedure for deesterification.

[0301] The general procedure for solution phase peptide synthesis using HBTU is as described in Example 1.

[0302] Solution phase amide formation using PyCloP was as described in Example 1.

[0303] Peptide purification and analysis was as described in Example 1.

[0304] [Table 5]

[0305] [Antibacterial Assay] MIC determinations for Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591 and Methicillin-resistant Staphylococcus epidermidis (MRSE) ATCC 27626 were performed by Toslab AS using standard methods. Amsterdam, D. (1996) "Susceptibility testing of antimicrobials in liquid media" in Antibiotics in Laboratory Medicine, 4th ed. (Lorian, V. ed.), pp. 75-78, Williams & Wilkins, Baltimore.

[0306] [Table 6]

[0307] [Example 6] [In vitro broad panel screening of selected compounds] Materials and Methods [Antibacterial agents] Pre-weighed vials of compound 7 and compound 8 were supplied by Lyticu Biopharma.

[0308] [Table 7]

[0309] [Bacterial isolate] The bacterial isolates used in this study were as described in Example 2. [Minimum inhibitory concentration (MIC) measurement] MICs were determined as described in Example 2.

[0310] [result] The results are shown in Table 6 in single line listing format.

[0311] The MIC data obtained are very encouraging and indicate that the peptide has a very broad spectrum of activity.

[0312] [Table 8] TIFF2024523026000016.tif227159TIFF2024523026000017.tif227159TIFF2024523026000018.tif227159

[0313] [Example 7] [In vivo activity of Compound 7 and Compound 8] Mice were skin infected with S. aureus or S. pyogenes and then administered a total of three doses at 3-hour intervals. Three hours after the last dose, skin biopsies were taken and the number of colony forming units (CFU) present in the skin samples was determined. The results are shown in Figures 3, 4, and 5 as the number of colony forming units per mouse.

[0314] In experiment 1 (Figure 3), compound 7 was applied to the skin of mice as part of a cream or gel containing 2% (w / w) compound 7. The same cream or gel without compound 7 was used as a negative control (placebo). Bactroban 2% cream was used as a positive control. It was clearly evident that application of the cream or gel containing compound 7 to the skin of mice reduced the CFU count compared to the negative control, indicating that compound 7 exerted an antibacterial effect against S. aureus. The efficacy of the standard clinical treatment, Bactroban 2% cream, was not significantly affected under this dosing regimen. The nature of the carrier, i.e. cream or gel, had no significant effect.

[0315] In experiment 2 (Figure 4), compound 7 was applied as gel at two different concentrations, namely 1% or 2%. A placebo gel and the known antibacterial agent "Bactroban (mupericin)" were used as controls. It can be seen that the gel containing compound 7 was more effective at reducing the number of CFUs from S. pyogenes CS301 infection than the placebo gel and Bactroban. Also, the gel containing 2% compound 7 was more effective than the gel containing only 1% compound 7.

[0316] In experiment 3 (Figure 5), compound 8 was applied in a 2% cream formulation against S. aureus FDA486 infection in a mouse skin infection model. A placebo cream and two known antibacterial agents, Fucidin (fusidic acid) ointment 2% and Bactroban (mupericin) cream 2%, were used as controls. It can be seen that the cream containing compound 8 was more effective at reducing CFU counts than placebo, Fucidin, or Bactroban.

[0317] [Example 8] [Impregnated polyurethane foam] Materials and Methods Bacterial strain: Staphylococcus aureus ATCC29213 Naive or AMC-109-impregnated PU-foam wound dressing (Viaten, Coloplast)

[0318] [Preparation of PU-foam patches] A commercially available absorbent PU-foam wound dressing material (Viaten, Coloplast) was cut into 1 cm square patches (1 cm 2 ) were cut into pieces. 0.5 ml of 2 mg / ml AMC-109 in distilled water was carefully added to each patch to allow it to be saturated with AMC-109. The patches were then dried and returned to their original shape prior to microbial testing.

[0319] [Microbiology] S. aureus was diluted to 0.5 McFarland and spread onto Mueller-Hinton agar plates.

[0320] To determine whether the bactericidal effect of AMC-109 impregnation could be improved by moistening the dressing, 100 μl of NaCl was added to the dressing before application to the inoculated plates.

[0321] Wet and dry dressings impregnated with AMC-109 and naive controls (i.e., control dressings not impregnated with AMC-109) were placed on the inoculated plates. All experiments were performed in triplicate. The plates were incubated at 37°C for 16 hours. Thereafter, the MH-agar plates were examined for inhibition of bacterial growth and photographed for record purposes.

[0322] [result] *1mg / cm 2 A clear zone of inhibition (4 mm) was observed around the dry PU-foam dressing impregnated with AMC-109 (Figure 6A). * 1mg / cm 2 A clear zone of inhibition (2 mm) was observed around the moistened PU-foam dressing impregnated with AMC-109 (Figure 6B). * No zone of inhibition was observed around the control dressing (Figure 6C).

[0323] [Conclusion] AMC-109 (1 mg / cm 2 A PU-foam dressing impregnated with AMC-109 clearly inhibited bacterial growth beneath the dressing and also formed a surrounding inhibition zone. This result indicates that AMC-109 is released from the foam into the underlying agar, eliminating the bacteria. This effect was not improved by pre-wetting the dressing, suggesting that the water vapor present in the incubator alone is sufficient to release AMC-109 from the dry dressing.

[0324] These findings support the use of AMC-109 impregnated PU-foam dressings as a method to control dressing colonization and for the prevention or treatment of infection in the underlying wound to which such AMC-109 dressings are applied.

[0325] [Example 9] [Example of impregnated polyurethane (non-foam)] [introduction] As shown in Example 8, the antimicrobial peptide AMC-109 can be impregnated into polyurethane foam and the peptide can be released from the polyurethane foam to exert its antimicrobial activity.

[0326] Further polyurethane impregnation studies were carried out as described below. To make the use of peptides more economical (peptides are relatively expensive), it may be desirable to only impregnate the surface layer of the material (polyurethane), especially in thick walled products.

[0327] In this study, it was shown that the absorption of AMC-109-containing swelling agent (AMC-109-containing solution) by polyurethane can be controlled by controlling the swelling time, and that even with a short swelling time, the antibacterial activity of polyurethane impregnated with AMC-109 is good.

[0328] Materials and Methods [Production of impregnated polyurethane] The polyurethane used was 1 mm thick Pellethane 80A sheet (Lubrizol Advanced Materials, Inc., USA). Pellethane is a biocompatible aromatic polyurethane. The sheet was cut into 2 × 1 cm samples. The Pellethane used in this study was not a foam.

[0329] 0.18 g of AMC-109 was mixed in 4 ml of ethanol and 2 ml of chloroform resulting in a 2.8% solution.

[0330] The polyurethane samples were immersed in the swelling agent (i.e., AMC-109 in ethanol / chloroform) for two different times, resulting in different absorption rates (i.e., different swelling degrees of the polyurethane) with the aim of achieving 10% and 100% absorption rates.

[0331] After immersion, the samples were surface dried with a cellulose wipe, weighed, dried at 20°C for 12 hours, bagged and labeled.

[0332] "% Absorption" is the % weight gain of the polyurethane after application of a solution of a compound of formula (I) (i.e., after swelling), i.e., the % weight gain of the polyurethane compared to the weight of the polyurethane before application of the swelling agent (i.e., before swelling).

[0333] [Microbiological testing of impregnated polyurethane] Overnight colonies of Staphylococcus epidermidis RP62A were cultured at 0.5 McFarland (1 × 10 8 The bacterial solution was diluted to 1 × 10 CFU in tryptic soy broth medium (1 × 10 5 ) and 100 μl of the diluted solution was dropped onto the surface of a polyurethane sample. The polyurethane sample was placed on a slide glass, and the slide glass was placed in a humidified incubation chamber and incubated at 37° C. for 24 hours.

[0334] To measure CFU (colony forming units), the polyurethane samples (after incubation with the bacterial solution as described above) were vortexed in 2 ml of 0.85% NaCl and serial dilutions (10 -1 ~10 -6 ) were prepared. 100 μl aliquots of the serial dilutions were streaked onto blood agar plates and further incubated overnight before CFU counting. All experiments were performed in duplicate.

[0335] [Results and Discussion] [Table 9]

[0336] These results indicate that swelling agents, including AMC-109, are capable of swelling polyurethanes, and that different exposure times (swelling times) result in different degrees of absorption (swelling).

[0337] Both sample 37 / 20 (i.e. 3 min exposure / swelling time) and sample 42 / 20 (i.e. 10 h exposure / swelling time) showed efficient antibacterial activity in microbiological assays. The control sample showed high levels of bacterial surface colonization.

[0338] Without wishing to be bound by theory, it is believed that during the swelling process, a concentration gradient exists, where the outer layer of the polyurethane (i.e., the polyurethane closest to or on the surface) is saturated, while the inner layer (furthest from the surface) is only partially saturated. It is believed that stopping the swelling process before the entire polyurethane sample / article reaches full saturation will result in an entire polyurethane sample / article in which the surface / outer layer contains the desired concentration of peptide, which can be determined by the peptide concentration of the swelling agent and the total absorption at saturation. It is believed that the inner layer of the polyurethane (i.e., the polyurethane further / furthest from the surface) contains less peptide than the surface / outer layer. In other words, and also without wishing to be bound by theory, it is believed that by controlling the swelling time, it is possible to control the extent (or depth) to which the swelling agent (and thus the peptide) penetrates the polyurethane. It is therefore believed that by controlling the swelling time, it is possible to control the impregnation of the polyurethane, and, if desired, to achieve impregnation of only the surface / outer layer of the polyurethane. Considering the cost of materials (e.g., the cost of peptides), impregnating only the surface and outer layer of the polyurethane (i.e., impregnating only a portion of the total thickness of the polyurethane) has a cost advantage compared to impregnating the entire polyurethane product (i.e., the entire thickness of the polyurethane sample). And the thickness of the impregnated portion (or layer) can determine the elution rate of the peptide and the time until the peptide is eluted. Impregnating the polyurethane article with antimicrobial peptides throughout the entire thickness of the article may not be necessary in all intended applications.

[0339] [Example 10] The aim of this study is to investigate whether TPU (thermoplastic polyurethane) polymers can be dissolved in solvents compatible with AMC-109 dissolution. The results show that THF (tetrahydrofuran) and dichloromethane (DCM) are very common solvents for this dissolution, and that a coating solution (i.e., AMC-109 and TPU dissolved in a solvent) can be applied to a surface to provide a painted surface (coating). The study also shows that AMC-109 can be extracted from the coating (i.e., eluted from the coating), and that the AMC109 / TPU coating has good anti-colony activity.

[0340] Materials and Methods [Sample material] Tecoflex is a commercially available medical grade TPU (Lubrizol). The type of Tecoflex used was Tecoflex EG-80A. Pearlcoat DIPP119 is a commercially available TPU (Lubrizol). Estane 58300 is a commercially available TPU (Lubrizol). Properties of the sample materials are shown in Table C.

[0341] [Table 10]

[0342] [Solution separation experiment] Samples (0.01–0.2 g) of each TPU material were placed in vials containing either tetrahydrofuran (THF), dichloromethane (DCM), acetone, ethyl acetate (EtOAc), or ethanol (EtOH). Solubility was assessed visually after 48 h at ambient temperature.

[0343] [Preparation of coating solution] Selected TPU sample materials were dissolved in THF. For this, Tecoflex (1.0 g) was dissolved in THF (tetrahydrofuran) (40 ml) or Pearlcoat DIPP119 (1.0 g) was dissolved in THF (25 ml) (Table D). AMC-109 (53 mg) was also dissolved in THF (4 ml) (Table D). AMC-109 dissolved in THF was then mixed with TPU (i.e., Tecoflex or Pearlcoat DIPP119) dissolved in THF. This mixture is referred to as the "coating solution" (or "coating solution" or "final coating solution"). The concentration of AMC-109 in the final coating solution was 5% relative to TPU. Dissolution of AMC-109 in THF takes several hours.

[0344] [Table 11]

[0345] [Painting procedure] Paint samples were prepared by placing 8 ml of the coating solution on a shallowly indented aluminum foil or by pouring the coating solution onto a watch glass. After drying (a few days), fairly thick coatings could be mechanically peeled off the front side. Figure 7 shows a Tecoflex coating impregnated with AMC-109 that was mechanically peeled off the back side after drying.

[0346] [extraction] Samples were cut from the coating, accurately weighed (100-150 mg), and the amount of AMC-109 in the sample was calculated. The samples were placed in vials, water (2 ml) was added, and the vials were shaken. Six consecutive extractions were performed. For each extraction, the old extract was replaced with deionized water (2 ml). Extractions were performed with shaking for 10 s, 5 min, 30 min, 3 h, 22 h, and 48 h. The amount of AMC-109 in each extract was measured by UV spectrophotometer at 280 nm using a previously prepared standard curve.

[0347] [Microbiology] Bacterial strains: * Staphylococcus aureus 8325 [Amended AATCC-100 Law] An overnight colony of S. aureus was diluted to 0.5 McFarland with 0.9% NaCl to give a bacterial concentration of 1.5 × 10 8 The suspension was further diluted with TSB (tryptic soy broth) to 1 × 10 5 It was expressed as CFU / ml.

[0348] The TPU material (i.e., the coating containing AMC-109) was cut into approximately 0.4 × 0.4 cm pieces. The material was then immersed in dH2O for 2 minutes and air-dried before use. Different samples (materials) were soaked in 100 μl of bacterial solution (i.e., 100 μl of 1 × 10 5 The samples were placed on glass slides and incubated in a water vapor chamber at 37°C for 24 hours. Two biological replicates were prepared for each test substance.

[0349] After incubation, the TPU material was placed in 1000 μl of NaCl (0.9%) and vortexed for 45 s before being serially diluted (0–10 -6 ) and 100 μl was plated and CFU counts were performed.

[0350] [result] The solutions of the TPU material in each solvent after standing at room temperature for 48 hours are summarized in Table E.

[0351] [Table 12]

[0352] Tetrahydrofuran (THF) appears to be the most effective solvent for the TPU samples. AMC-109 dissolves in THF, albeit very slowly. Dichloromethane (DCM) also dissolved the TPU samples very effectively. Experiments showed that AMC-109 also readily dissolves in chloroform (data not shown).

[0353] [coating]

[0354] [Table 13]

[0355] [Extraction and leakage kinetics] The amount of AMC-109 in each extract was calculated using a UV-spectrophotometric standard curve. Data was normalized to the total amount of AMC-109 present in the original sample. The normalized data is summarized in Table G.

[0356] [Table 14]

[0357] [Microbiological efficacy] [Colony forming unit] The materials (i.e., the coatings containing AMC-109) were washed thoroughly for 2 minutes to remove any AMC-109 that was readily extractable or present directly on the surface. CFU counts were below the detection limit for the AMC-109-containing materials. Compared to the control material (i.e., the related TPU coating without AMC-109), the CFU counts were reduced by 7 logs (Table H).

[0358] [Table 15]

[0359] [Conclusion] *TPU can be dissolved in several solvents. Among the solvents tested, THF and dichloromethane are the most versatile. *AMC-109 dissolved in a solvent (e.g. THF) can be mixed with a polymer (TPU) dissolved in a solvent (e.g. THF). *The resulting coating solution can be applied to multiple surfaces. *The properties of the paint surface vary depending on the polymer (TPU), and different polymers are suitable for different applications. *Painted surfaces (coatings) leach AMC-109 (i.e., AMC-109 leaches out), typically quickly at first and then persists in low concentrations for at least 2 days. *Coated surfaces exhibit strong anti-colonization properties (even after a 2-minute wash with water to remove any AMC-109 that was readily extractable or present directly on the surface).

[0360] This work indicates that compositions comprising AMC-109, TPU, and a suitable solvent (e.g., THF), also referred to as AMC-109-containing paints (or AMC-109 / TPU-containing paints), are useful as paints (or in providing coatings) for surfaces susceptible to microbial contamination, as such paints (coatings) resist the growth of microorganisms thereon.

[0361] [Research Expansion] As an extension of the above mentioned studies, experiments were carried out to measure the ability of samples of Tecoflex-AMC-109 and Pearlcoat Dipp119-AMC-109 coatings / films to resist colonization by bacteria (S. aureus) even after the samples were subjected to an extract of AMC-109 (by shaking in water for different periods of time) (both were carried out using coating solutions made by mixing TPU dissolved in THF with AMC-109 dissolved in THF). Such extracted samples of Tecoflex-AMC-109 coatings were observed to be decolonized by S. aureus for at least 20 hours (data not shown). Also, such extracted samples of Pearlcoat Dipp119-AMC-109 coatings were observed to be decolonized by S. aureus for at least 3 hours (data not shown).

[0362] [Example 11] The aim of this study was to investigate whether a TPU (thermoplastic polyurethane) coating containing AMC109 could be applied to a urinary catheter (in this example, the urinary catheter is made of silicone) and whether this AMC109 / TPU coating would impart antibacterial properties.

[0363] [Materials and Methods (Preparation of Coating Solution and Coating Procedure)] [Sample material] Tecoflex TPU is a commercially available medical grade TPU (Lubrizol). Tecoflex is an aliphatic polyether-based thermoplastic polyurethane (TPU). The type of Tecoflex used in this study was Tecoflex EG-80A.

[0364] Pearlcoat DIPP119 is a commercial TPU (Lubrizol). Pearlcoat DIPP119 is an aromatic polycaprolactone copolyester-based thermoplastic polyurethane (TPU).

[0365] [Preparation of coating solution] Tecoflex (1.0 g) was dissolved in THF (40 ml) or Pearlcoat DIPP119 (1.0 g) was dissolved in THF (25 ml). AMC-109 (53 mg) was also dissolved in THF (4 ml). The AMC-109 dissolved in THF was then mixed with the TPU (i.e., Tecoflex or Pearlcoat DIPP199) dissolved in THF. This mixture is referred to as the "final coating solution." The concentration of AMC-109 in the final coating solution was 5% relative to TPU. Dissolution of AMC-109 in THF takes several hours.

[0366] [Painting procedure] A piece of Covidien Foley catheter (a silicone urinary catheter) was split lengthwise and immersed in either 44 ml of a final coating solution of Tecoflex and AMC-109 in THF as described above, or 29 ml of a final coating solution of Pearlcoat DIPP119 and AMC-109 in THF as described above. The sample (i.e., the immersed piece of catheter) was then allowed to dry. As a control, an equivalent coating made with a solution without AMC-109 was made.

[0367] [Materials and Methods (Microbiology)] Bacterial strains: * Staphylococcus aureus 8325

[0368] [Modified AATCC-100 method] An overnight colony of S. aureus was diluted to 0.5 McFarland with 0.9% NaCl to give a bacterial concentration of 1.5 × 10 8 The suspension was further diluted with TSB (tryptic soy broth) to 1 × 10 5 It was expressed as CFU / ml.

[0369] The test material (i.e., the painted and dried catheter) was cut into pieces of approximately 1 cm. The different samples were placed on the hollow side (i.e., the lumen side) of the tube with 50 μl of bacterial solution (i.e., 1 × 10 5 The samples were inoculated with 50 μl of CFU / ml suspension. The samples were placed on glass slides and incubated in a water vapor chamber at 37°C for 24 hours. Three biological replicates were prepared for each test substance.

[0370] After incubation, the test substance was added to 900 μl of NaCl (0.9%), vortexed for 45 s, and then serially diluted (0–10 -6 ) and 100 μl was plated and CFU counts were performed.

[0371] [result] [Microbiological efficacy] [Colony forming units] CFU counts were below the limit of detection for materials containing AMC-109. Compared to the control material, CFU counts were reduced by 7 logs (Table B).

[0372] [Table 16]

[0373] [Conclusion] Coatings consisting of AMC-109 and TPU dissolved in THF were successfully applied as coatings on silicone urinary catheters, as demonstrated with two different TPUs (Tecoflex and Pearlcoat Dipp119).

[0374] Painted (i.e., coated) urinary catheters demonstrated superior antibacterial and anticolonial activity.

[0375] This work shows that compositions comprising AMC-109, TPU and a suitable solvent (e.g., THF), also referred to as AMC-109-containing coatings (or AMC-109 / TPU-containing coatings), are useful for coating articles susceptible to microbial contamination (e.g., medical devices) because articles so coated resist microbial growth.

[0376] [Example 12] The objective of this study was to investigate the release characteristics of AMC-109 from AMC-109-containing thermoplastic polyurethane (Tecoflex) coatings (i.e., from surfaces coated with such coatings). The antibacterial properties of AMC-109-containing thermoplastic polyurethane (TPU) coatings were also investigated.

[0377] Materials and Methods [Sample material] A stock coating solution of Tecoflex EG80A (Lubrizol Advanced Materials, Inc.) and AMC-109 was prepared by mixing 920 mg of Tecoflex in 30 ml of THF (tetrahydrofuran) with 50 mg of AMC-109 in 1 ml of THF. This stock coating solution was divided into three portions. *10ml stock Tecoflex and AMC-109 paint (approximately 5% AMC-109 to Tecoflex) *10ml stock Tecoflex and AMC-109 paint + PEG400 (112mg). *10ml stock of Tecoflex and AMC-109 paint + PEG 1000 (108mg)

[0378] In two of the three cases above, the PEG added to the paint as a potential release enhancer was either an average molecular weight of 400 (PEG400) or 1000 (PEG1000). Thin films of AMC-109-containing Tecoflex paint were made by immersing Tecoflex samples (square sheets with edges cut to approximately 1.5 cm) in the paint solution and hanging them on clips to dry. For the avoidance of doubt, in these experiments Tecoflex was the TPU used in the paint and Tecoflex was also the sample material to which the paint was applied (i.e., Tecoflex was also the material that was painted with AMC-109-containing Tecoflex paint).

[0379] [AMC-109 release experiment (extraction experiment)] Each painted sample was divided into three equal parts and placed into vials containing 1.5 ml of water. The vials were placed on an orbital shaker. At a series of time intervals (10 min, 3 h, 20 h, 2 days, 5 days, 8 days, 14 days, and 18 days), the aqueous extract was aspirated and replaced with 1.5 ml of fresh water, and the vials were placed back on the shaker. The aqueous extracts taken at each time interval were analyzed for AMC-109 content by UV-Vis method (i.e., the amount of AMC-109 in each extract was measured by UV spectrophotometer at 280 nm using a previously prepared standard curve).

[0380] [Microbiology] Bacterial strains: *Staphylococcus aureus 8325 *Escherichia coli

[0381] [Modified AATCC-100] An overnight colony of S. aureus was diluted to 0.5 McFarland with 0.9% NaCl to a bacterial concentration of 1.5 × 10 8 The solution was further diluted with TSB (tryptic soy broth) to obtain 1 × 10 5 The results were calculated as CFU / ml. The same procedure was carried out for E. coli.

[0382] The test materials (i.e., the painted samples) were cut into pieces of approximately 1 × 1 cm. Different samples (test materials) were added with 50 μl of bacterial suspension (1 × 10 5 The samples were incubated in a steam bath at 37°C for 24 hours. Three biological replicates were prepared for each test substance.

[0383] After incubation, the test substance was placed in 900 μl of NaCl, vortexed for 45 seconds, and then serially diluted (0–10 -6 ) and 100 μl was plated and CFU counts were performed.

[0384] [result] [Create a painted coupon] A set of three paint samples was prepared for each paint type (i.e., for each of the three paint solutions listed in the bullet points above). Thus, three sets (three samples per set) of paint samples were prepared that were painted with the paint containing AMC-109 (active paint). In addition, one set (three samples per set) of paint samples was prepared that was painted with Tecoflex paint only (i.e., no AMC-109); this served as a control for the microbiology experiments. The paint sample masses ranged from 682 mg to 772 mg, and the paint layer masses ranged from 6.09 mg to 8.87 mg. The paint layer masses for each active paint sample are summarized in Table I below. The paint layer thicknesses were calculated to be 10-20 μm, but there is likely to be significant non-uniformity in the layer thickness.

[0385] [Water extraction (release)] The painted samples were extracted into vials containing 1.5 ml of water (extraction in water means that the sample is exposed to water and AMC-109 is released or extracted from the paint layer). The amount of water (1.5 ml) was chosen to represent "sinking" conditions while providing a volume of water that would allow the amount of AMC-109 released (or extracted) into the water to be measured by the UV method (a large volume of water can make it difficult to measure the released / extracted AMC-109). Each extract (except the first) contained less than 10 μg of AMC-109 in 1.5 ml of water, indicating that there is at most minimal backflow of AMC-109 into the paint. The water extracts were replaced with fresh water at each time point, as above. The extraction data are shown in Table I.

[0386] [Table 17]

[0387] The amount of AMC-109 extracted was converted to mg / hour to correct for variations in sampling rate. The raw data is shown in Table J below.

[0388] [Table 18]

[0389] Eighteen days after aqueous extraction, the experiment was stopped and the paint samples were microbiologically tested using a modified AATCC-100 method, at which time the paint samples had lost 30% of the AMC-109 in the paint layer.

[0390] [Anti-colony effect] The anticolonial effect after 18 days of continuous aqueous extraction was evaluated against Staphylococcus aureus and Escherichia coli using a modified AATCC-100 method, in which the surface of the painted samples was inoculated directly with bacteria and incubated at 37°C for 24 hours. The antimicrobial effect against the inoculum was determined by measuring the number of colony forming units (CFU) at the end of incubation. The results of the anti-colonization effect against Staphylococcus aureus are shown in Table K below.

[0391] [Table 19]

[0392] The results in Table K show that surfaces coated with AMC-109-containing TPU coatings were not contaminated with Staphylococcus aureus even after exposure to water for at least 18 days.

[0393] The results of the anti-colony effect against E. coli are shown in Table L.

[0394] [Table 20]

[0395] The results in Table L show that surfaces coated with AMC-109-containing TPU coatings were not contaminated with E. coli even after exposure to water for at least 18 days.

[0396] For the avoidance of doubt, the "AMC-109" sample types in Tables K and L are samples that were painted with the AMC-109 containing TPU paint described in the first bullet point of the "Sample Materials" section above. The "AMC-109+PEG400" sample type in Tables K and L are samples painted with the AMC-109 containing TPU paint listed in the second bullet point in the "Sample Materials" section above. The "AMC-109+PEG1000" sample type in Tables K and L are samples that were painted with the AMC-109 containing TPU paint listed in the third bullet point in the "Sample Materials" section above. The "Tecoflex" sample type in Table K is a sample painted with Tecoflex paint only (i.e., there is no AMC-109 in the paint). The "Substance Only" sample type in Table K is an unpainted sample (i.e., unpainted Tecoflex material). The "Control" sample type in Table L is a sample painted with Tecoflex paint only (i.e., no AMC-109 was present in the paint).

[0397] [Conclusion] Water extraction experiments were set up to mimic the conditions in which the equipment was subjected to continuous water flow for 18 days. On average, it was found that just under 30% of the AMC-109 content was extracted during this time. Of the total amount extracted, 12-15% was released after 10 minutes, while the remaining portion (85-88%) was released slowly at a fairly constant rate for the remainder of the extraction time. This data indicates that the AMC-109-containing TPU coating was sufficient to inhibit bacterial colonization on the coating surface, even after nearly three weeks of continuous water washing.

[0398] The main findings of this study are as follows: * Thin films of Tecoflex containing AMC-109 can be applied to a surface using dipping techniques, thus painting the surface of a material with a TPU paint containing AMC-109 to provide the material with a painted surface. * AMC-109 release (or extraction) is overwhelmingly large during the first 10 minutes, then levels out at a low but steady level that lasts for at least 18 days. * The surface of a thin TPU film (or paint) containing AMC-109 will not be contaminated by Staphylococcus aureus or Escherichia coli for at least 18 days. *Mass balances suggest that, on average, just under 30% of the AMC-109 present in a Tecoflex paint layer leaches (i.e., is released or extracted from) the material within 18 days, 12-15% of this amount is released within 10 minutes, and the remainder slowly flows out at a fairly constant rate. Thus, this data indicates that there is a sustained release of AMC-109 over time.

Claims

1. 1. An antimicrobial article comprising polyurethane, The polyurethane is an antimicrobial article impregnated with a compound of formula (I). AA-AA-AA-X-Y (I) [In the formula, in any order, two of the AA moieties are cationic amino acids and one of the AA moieties is an amino acid having a lipophilic R group having 14 to 27 non-hydrogen atoms; X is a N atom and may incorporate up to two heteroatoms selected from N, O, and S; 1 ~C 10 may be substituted with an alkyl or aryl group; Y is R 1 -R 2 -R 3 , R 1 -R 2 -R 2 -R 3 , R 2 -R 2 -R 1 -R 3 , R 1 -R 3 and R 4 is selected from the group consisting of During the ceremony, R 1 is C, O, S or N, R 2 is C, R 1 and R 2 Each of the 1 ~C 4 may be substituted or unsubstituted with an alkyl group; R 3 is a group containing 1 to 3 cyclic groups each containing 5 or 6 non-hydrogen atoms, two or more of which are optionally fused, and one or more of which are optionally substituted; R 3 incorporates up to 15 non-hydrogen atoms, R 4 is a linear, branched, or cyclic aliphatic moiety having 2 to 20 non-hydrogen atoms.

2. The antimicrobial article of claim 1 , wherein the compound is a peptide.

3. 2. The antimicrobial article of claim 1, wherein the cationic amino acid is arginine and / or lysine.

4. 2. The antimicrobial article of claim 1, wherein the amino acid having a lipophilic R group is selected from tributyltryptophan (Tbt) or a biphenylalanine derivative selected from Phe(4-(2-naphthyl)), Phe(4-(1-naphthyl)), Bip(4-n-Bu), Bip(4-Ph) or Bip(4-T-Bu); Bip(4-(2-naphthyl)).

5. 2. The antimicrobial article of claim 1, wherein the compound is a compound of formula (II). AA 1 -AA 2 -AA 1 -X-Y (II) [In the formula, A.A. 1 is a cationic amino acid, A.A. 2 is an amino acid having a lipophilic R group having 14 to 27 non-hydrogen atoms, X and Y are as defined in claim 1.

6. 2. The antimicrobial article of claim 1 , wherein the compound has the following structural formula: 【Chemistry 5】

7. 10. The antimicrobial article of claim 1, wherein the polyurethane is a thermoplastic polyurethane (TPU).

8. The antimicrobial article of claim 1 , wherein the polyurethane is not in the form of a foam.

9. The antimicrobial article of claim 1 , wherein the polyurethane impregnated with the compound is in the form of a coating on the article.

10. The antimicrobial article of claim 1 , wherein the antimicrobial article is a medical device.

11. The antimicrobial article of claim 1 , wherein the antimicrobial article is a wound dressing.

12. The antimicrobial article of claim 1 , wherein the antimicrobial article is an indwelling medical device.

13. The antimicrobial article of claim 1 , wherein the antimicrobial article is a catheter.

14. A polyurethane impregnated with the compound according to claim 1.

15. 15. The impregnated polyurethane of claim 14, wherein the impregnated polyurethane or the compound is defined in claim 1.

16. 2. A method for the preparation of a polyurethane, not in the form of a foam, impregnated with a compound as defined in claim 1, comprising the steps of: The method comprises: (i) applying a solution of a compound as defined in claim 1 to said polyurethane, wherein the solvent is an organic solvent; (ii) drying the polyurethane to which the solution has been applied, thereby producing a polyurethane impregnated with the compound defined in claim 1. The method includes:

17. 17. A polyurethane impregnated with a compound as defined in claim 1, said polyurethane being produced by the method of claim 16.

18. the polyurethane is not in the form of a foam, The compound is impregnated into the polyurethane over only a portion of the total depth from the surface of the polyurethane. A polyurethane impregnated with a compound as defined in claim 1.

19. A composition comprising at least one organic solvent, a thermoplastic polyurethane (TPU) and a compound as defined in claim 1, A composition wherein said TPU and said compound are each dissolved in said at least one organic solvent.

20. 20. The composition of claim 19, wherein the organic solvent is a polar aprotic solvent.

21. 20. The composition of claim 19, wherein the organic solvent is tetrahydrofuran (THF), dichloromethane (DCM), acetone or ethyl acetate.

22. 20. The composition of claim 19, wherein the organic solvent is THF.

23. 20. A method for producing the composition of claim 19, comprising the steps of: The method further comprising: (i) dissolving a thermoplastic polyurethane (TPU) in an organic solvent; (ii) dissolving a compound as defined in claim 1 in a solvent; (iii) mixing the TPU dissolved in the organic solvent obtained in (i) with the compound dissolved in the solvent obtained in (ii), thereby producing the composition. Includes Manufacturing method.

24. 24. The method of claim 23, wherein the solvent in (ii) is an organic solvent.

25. 24. The method of claim 23, wherein the solvent in (i) and / or (ii) is as defined in claim 21.

26. 24. The method of claim 23, wherein the solvent in (i) is the same as the solvent in (ii).

27. 24. The method of claim 23, wherein the solvent in (i) is different from the solvent in step (ii).

28. (i) providing a first solution comprising a thermoplastic polyurethane (TPU) in an organic solvent; (ii) providing a second solution comprising a compound of formula (I), said second solution being miscible with said first solution; and (iii) mixing the first solution with the second solution Including, 20. The method of claim 19.

29. 29. The method of claim 28, wherein the organic solvent is defined in claim 20.

30. 29. The method of claim 28, wherein the second solution comprises a compound of formula (I) and an organic solvent.

31. 29. The method of claim 28, wherein the organic solvent is defined in claim 20.

32. 1. A method for producing a coating for an article or surface susceptible to microbial contamination, the method comprising: (i) applying to said article or surface the composition of claim 19; (ii) removing the solvent from the applied composition by evaporation. The method includes:

33. A coating for an article or surface susceptible to microbial contamination comprising a thermoplastic polyurethane impregnated with a compound of formula (I) as defined in claim 1.

34. 34. The coating of claim 33, wherein the coating is produced by applying the composition of claim 19 to the article or surface and evaporating the solvent from the applied composition.

35. A method for producing an article or surface having an antimicrobial coating comprising a thermoplastic polyurethane impregnated with a compound as defined in claim 1, comprising the steps of: The method comprises: (i) providing the composition of claim 19; and (ii) applying said composition to said article or surface, or to at least a portion of said article or surface. method.

36. said applying comprising immersing said article or said surface in said composition; or 36. The method of claim 35, comprising applying the composition onto the article or surface.

37. An article susceptible to microbial contamination coated or at least partially coated with the coating composition of claim 19 or the coating of claim 33.

38. 20. Use of the composition of claim 19 for coating or at least partially coating an article or surface susceptible to microbial contamination or colonization.

39. The coating of claim 33, wherein the article is a medical device.

40. 2. The antimicrobial article of claim 1, wherein the impregnated polyurethane has the characteristics of claim 1.

41. The polyurethane includes a polyol-derived moiety that enables the polyurethane to absorb water. The antimicrobial article of claim 1.

42. The polyol is a polyether polyol.

42. The antimicrobial article of claim 41.

43. The polyurethane is produced by reacting a polyether polyol with an aliphatic diisocyanate. The antimicrobial article of claim 1.

44. In use, there is a sustained release of the compound of formula (I) from the polyurethane. The antimicrobial article of claim 1.

45. 2. The impregnated polyurethane of claim 1 for use in therapy.

46. A compound according to claim 1 for use in therapy, The compound is administered to a subject in the form of an antimicrobial article comprising polyurethane impregnated with the compound. A compound for use in therapy.

47. 46. ​​The impregnated polyurethane for use in claim 45, wherein said therapy is the treatment or prevention of an infection in a subject.

48. A composition for treating or preventing an infection comprising a therapeutically effective amount of a compound according to claim 1, A composition, wherein the compound is in the form of an antimicrobial article comprising a polyurethane impregnated with the compound.

49. 13. Use of a polyurethane impregnated with a compound according to claim 1 in the manufacture of an antimicrobial article or medicament for use in therapy, preferably for use in the treatment or prevention of infection.

50. 48. The impregnated polyurethane for use in claim 47, wherein the infection is a bacterial infection.

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