Functionalized carbon nanoparticles with surfactant and Anti-pathogenic properties

Abstract

The invention relates to carbon nanoparticle derivatized with at least one substituent covalently bonded to a carbon atom of said carbon nanoparticle, the use of said nanoparticle, said carbon nanoparticle for use in the treatment or prevention of an infectious disease, an antimicrobial, cosmetic or coating composition comprising said carbon nanoparticle and an antimicrobial device comprising a polymer or resin that contains said nanoparticle.

Description

[0001] FUNCTIONALIZED CARBON NANOPARTICLES WITH SURFACTANT AND ANTI-PATHOGENIC PROPERTIES

[0002] Field of the invention

[0003] The invention relates to a carbon nanoparticle derivatized with at least one substituent covalently bonded to a carbon atom of said carbon nanoparticle, the use of said nanoparticle, said carbon nanoparticle for use in the treatment or prevention of an infectious disease or as an oral care composition, a pharmaceutical, antimicrobial, cosmetic or coating composition comprising said carbon nanoparticle and an antimicrobial device comprising a polymer or resin that contains said nanoparticle.

[0004] Background of the invention

[0005] A carbon nanoparticle (CNP) is a nanoscale structure composed primarily of carbon atoms, typically with dimensions ranging from 1 to 100 nanometers. Prominent representatives of this class are fullerenes, carbon nanotubes and graphene.

[0006] Since their discovery in 1985 fullerenes, and carbon nanoparticles in general, have been the subject of much research across multiple scientific disciplines, including physics, chemistry, materials science, biology and life sciences. More recently, particularly in the last decade, fullerenes and their derivatives have been of interest to the fields of wellness, cosmetics and medicine, due to their varied and promising physiological activities, antioxidant capabilities and, particularly, antibacterial activity.

[0007] In recent years, the problem of contamination by pathogenic organisms, particularly bacteria and fungi, combined with the proliferation of antibiotic-resistant bacteria, means that there is an increasing demand for new products that can safely and effectively kill or inhibit the proliferation of such pathogens. Methicillin-resistant Staphylococcus aureus (MRSA) is among the best-known multi -resistant bacteria, wherein public consciousness towards said bacteria peaked in recent years. Whilst treatment outcomes for MRSA have improved in the last two decades, it, and other antibiotic-resistant bacteria, continue to be a significant problem.

[0008] Outside of the obvious medical needs and applications of such products, there is a growing need for safe and effective preservative agents in cosmetics, particularly since the restriction andbanning of multiple classes of parabens in EU and ASEAN regulatory-compliant territories, which cover a significant portion of the global cosmetic market both in terms of manufacturing and consumption. Cosmetics are particularly vulnerable because they are subject to frequent contamination by pathogens found on the skin when applied by the user, and because they often have a high water content and are stored in warm conditions which combine to make an excellent environment for pathogenic proliferation.

[0009] An additional and significant need in the field of antimicrobial substances is the need for compounds that can be safely and stably integrated into surfaces subject to frequent pathogenic contamination, such as door handles, taps and mobile phone cases. In places particularly vulnerable to pathogenic contamination, such as hospitals, restaurants or laboratories that handle biological samples, the list of items that would benefit from having an inherently antimicrobial surface extends even further, for example work counters, tools and floors. These compounds need not only to be effective, but must be reasonably mechanically and chemically stable and not be exhausted via either repeated touching or abrasion or via their method of antimicrobial action.

[0010] Quaternary ammonium compounds (QACs) are one of the most simple, effective and longstanding families of antimicrobial compounds, with a wide selection of variants of differing compositions and applications. Their general mechanism of operation is simple, which is to disrupt the cell membrane of the pathogen, leading to cell lysis and death. This well-defined mechanism has the added benefit of not exhausting the QAC in the process, meaning that a single molecule can kill multiple pathogenic microorganisms over a prolonged period.

[0011] WO 2024 / 197165 Al relates to a class of antifungal compounds, namely keto-alkyl-pyridinium compounds, that have broad- spectrum activity.

[0012] WO 2018 / 144823 Al relates to a fullerene-metal nanocomposite that comprises a metal nanoparticle bonded to a functionalized fullerene compound, wherein the fullerene-metal nanocomposite can be applied to a surface to provide it with antimicrobial activity.

[0013] However, pristine carbon nanoparticles, such as fullerenes, graphenes and carbon nanotubes, exhibit varying levels of cytotoxicity when in direct contact with human or animal cells, which have severely limited the scope of their use in products that are expected to come in direct contact with the end user. Medicines, cosmetics and the surfaces of handheld objects fall within this remit.Moreover, the small molecular size of many QACs make them unsuitable for direct application to or contact with the human body, as they can exhibit lytic or otherwise disruptive or damaging activity towards human or animal cells.

[0014] Hence, there is still a need for efficient and safe antimicrobial compounds, wherein said compounds show no or minor unwanted side effects. The objective of the present invention thus is to provide an improvement or an alternative to the prior art.

[0015] This problem is solved by the provision of a carbon nanoparticle derivatized with at least one substituent covalently bonded to a carbon atom of said carbon nanoparticle, wherein the substituent comprises at least one ammonium and / or cationic quaternary ammonium group with an appropriate anion according to claim 1. Specific embodiments are subject matter of further dependent claims.

[0016] Summary of the invention

[0017] In a first aspect the invention provides a carbon nanoparticle derivatized with at least one substituent covalently bonded to a carbon atom of said carbon nanoparticle, wherein the substituent comprises at least one ammonium and / or cationic quaternary ammonium group with an appropriate anion.

[0018] The inventors surprisingly found, that by derivatizing a carbon nanoparticle with a quaternary ammonium compound the beneficial properties of either compound can be combined, thereby resulting in a molecule providing antimicrobial action, physiochemical stability and surfactant activity whilst simultaneously mitigating negative qualities in terms of their irritative and toxic behavior towards human and animal cells.

[0019] QACs, due to their ionic nature, are highly polar, whereas carbon nanoparticles are non-polar. Therefore, combining both types of structures within a single molecule result in a family of molecules that possess amphiphilic properties that make them effective simultaneously as both surfactants and antimicrobial agents.

[0020] This family of molecules can be heavily modified to adjust their antimicrobial and physiochemical properties - the overall hydrophobicity, hydrophilicity, solubility and / or dispersibility in a variety of different media, as well as their ability to bond into part of a larger polymeric structure can all be controlled and determined by one skilled in the art by themolecular composition, molecular weight and molecular conformation of any given embodiment of the present invention.

[0021] The degree of quaternary ammonium group functionalization on the carbon nanoparticle can be adjusted. The quaternary ammonium groups themselves can take a variety of different forms with vastly different counterions which affect both the invention’s antimicrobial and physiochemical properties.

[0022] The quaternary ammonium groups themselves may be bound directly to the carbon nanoparticle, or they can be connected via various organic linking groups. These may themselves have further interstitial organic linking groups further distancing the quaternary ammonium groups from the carbon nanoparticle core. These organic linking groups may be polymerized, whether with each other or with multiple quaternary ammonium groups, resulting in pendant polymer chains, which can be of varying lengths and conformations, with varying degrees of quaternary ammonium group functionalization depending on how they are synthesized.

[0023] In addition, the invention is not restricted to only one carbon nanoparticle comprising at least one substituent covalently bonded to a carbon atom of said carbon nanoparticle. Instead, the carbon nanoparticle may be bonded to a plurality of substituents and, moreover, several carbon nanoparticles may be bonded indirectly via the substituents or directly to one another via a hydrocarbon group.

[0024] The variety of aspects and embodiments shown here and in the following means that the present invention can exist as a dry powder, a gel, a solid, a solution, a colloid or as part of a composite, with varying degrees of surfactant efficacy, if any. What qualities are to be exhibited by the invention are dependent upon the conditions in which the invention is expected to function. For example, when used for dispersion and preservation in cosmetic products (FIG. 1, EXAMPLE 4, FIG. 3, EXAMPLE 6) the inventive carbon nanoparticle has vastly different chemical structures compared to the use for incorporation in polymers (FIG. 2, EXAMPLE 5, FIG. 4, EXAMPLE 7).

[0025] Detailed description of the invention

[0026] It may be provided that the substituent is a linear, branched or cyclic organic group containing one or more ammonium groups, cationic quaternary ammonium groups or a quaternaryammonium salt polymer, each with their appropriate anions, or a mixture of said cationic species.

[0027] The above-mentioned substituents may provide a broad-spectrum antimicrobial activity, stability and long-lasting effects, low toxicity, versatility, water solubility, surfactant properties, compatibility with other materials and multiple functionalities, such as chemical intermediates, cosmetic additives, oilfield chemicals, and water treatment agents. The carbon nanoparticle may be tailored specifically to the intended use by using a substituent chosen from the list above, thereby providing a high flexibility and variety of both molecular structures and applications.

[0028] Notably, this does not exclude the nanoparticle from containing additional functional groups that are non-QAC functional groups. Non-QAC groups may provide increased stability in water for example by hydroxylating the nanoparticle, i.e., functionalizing the nanoparticle with hydroxide groups. Moreover, non-QAC groups may provide suitable means to bond the nanoparticle to specific materials.

[0029] Examples for non-QAC functional groups that are directly bound to the carbon nanoparticle are hydroxyls, carbonyls, carbonates, esters, ethers, epoxides, thiols, sulphoxides, thiocarbonates, thioesters, dithioesters, thioethers, episulphides, thioketones, urethanes, thiourethanes, amines, amides, imides, enamines, nitriles, halides, isocyanates, isothiocyanates, azides and sulphones. Where the carbon nanoparticle comprises a plurality of said non-QAC functional groups, it is feasible that the functional groups may all be of the same molecular structure or composition, or may be of different molecular structures or compositions.

[0030] It is further conceivable within the scope of the invention that the carbon nanoparticle is derivatized with substituents in a ratio of from 0.01 to 1.7 substituents per carbon atom of the carbon nanoparticle, preferably of from 0.02 to 0.8 substituents per carbon atom of the carbon nanoparticle, more preferably of from 0.05 to 0.5 substituents per carbon atom of the carbon nanoparticle, and even more preferably of from 0.1 to 0.25 substituents per carbon atom of the carbon nanoparticle.

[0031] Depending on the intended use, the number of substituents on the carbon nanoparticle may differ. Moreover, it is preferred for the substituents to be present on one side of the carbon nanoparticle, rather than being evenly distributed over the area of the nanoparticle. In other words, a clustered arrangement of the substituents is preferred.For example, in fullerenes it is preferred to have a “crown” conformation because that effectively leaves the hydrophobic fullerene much less sterically hindered to interact with nonpolar media. In line, in nanotubes it is preferred to have a similar conformation that would effectively leave the opposite site of the tube largely unsubstituted so that this site may interact with non-polar media.

[0032] Further, a higher degree of substitution on carbon nanoparticle directly reduces the cytotoxicity and hydrophobicity of the present invention, the former by reducing the direct contact of the carbon nanoparticle with cellular matter via steric hindrance and the latter by adding hydrophilic ammonium salts or quaternary ammonium groups to the hydrophobic carbon nanoparticle. Such increased substitution simultaneously decreases the radical-scavenging qualities of fullerenes, which are noted as one of their primary healthful effects. On the other hand, an excessive percentage of the molecule comprising hydrophilic ammonium salts or quaternary ammonium groups results in a molecule with low amphiphilicity and therefore weak surfactant properties, and may also result in reduced activity. Therefore, it is preferred to strike a balance between these properties to execute sufficient substitution that lends the inventive carbon nanoparticle sufficient antimicrobial and surfactant properties, but without unduly inhibiting its healthful radical-scavenging qualities or rendering it hydrophilic through excess substitution.

[0033] When the carbon nanoparticle is a fullerene, especially a Ceo fullerene, it is preferred that the fullerene is derivatized with n substituents, with n = 1 to 100 (refers to 0,0166 to 1,6666 substituents per carbon atom of the carbon nanoparticle of the fullerene). More preferably n = 2 to 50, even more preferably n = 10 to 40, and most preferably n = 6 to 12 or n = 24 - 32. For example, n may be any of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100.

[0034] In an embodiment of the invention the substituent is covalently bonded to the carbon nanoparticle.

[0035] Covalent bonds are the strongest chemical bonds and as such provide the greatest stability. Having the substituent bonded via a covalent bond allows the use of the nanoparticle also in harsh environments that would otherwise cause a weaker bond to break, thereby affecting the possible application.It may be provided that the one or more ammonium salts or quaternary ammonium groups may be bonded directly to the carbon nanoparticle. However, it may also be provided that the one or more ammonium salts or quaternary ammonium groups may be bonded to the carbon nanoparticle by way of a linking organic group.

[0036] The linking organic group may for example be attached to the carbon nanoparticle after the nanoparticle has been functionalized, i.e., after it received functional groups such as hydroxy groups which facilitate the coupling of a linking organic group.

[0037] It may be provided that the carbon nanoparticle is selected from the group consisting of a carbon nanotube (CNT), a fullerene, graphene, graphene oxide or a nanodiamond. In a further preferred embodiment, the carbon nanoparticle is a fullerene.

[0038] Different fullerenes of different molecular sizes and structure, and endohedral fullerenes containing a variety of different compounds within their carbon cages may be used. Different sizes of graphene sheet in single-layer, multi-layered, wrinkled or stacked conformations can be used, as can carbon nanotubes of single and multi-layered conformations. These may also be functionalized with additional, non-quaternary ammonium groups to adjust their physiochemical properties yet further or to allow their incorporation into a polymeric material.

[0039] A fullerene is an allotrope of carbon whose molecules consist of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five or six atoms. The molecules may have hollow sphere- and ellipsoid-like forms, or other shapes.

[0040] Graphene is another carbon allotrope consisting of a single layer of atoms arranged in a honeycomb planar nanostructure.

[0041] A carbon nanotube (CNT) is a cylindrical nanostructure composed of carbon atoms arranged in a hexagonal lattice. These tube-shaped carbon molecules have diameters on the nanometer scale, typically ranging from 0.4 to 3 nanometers for single-walled carbon nanotubes (SWCNTs).

[0042] Notably, one or more graphene sheets or one or more carbon nanotubes or one or more fullerenes may be bonded to one or more quaternary ammonium groups. Graphene sheets and carbon nanotubes comprise carbon atoms arranged in a hexagonal structure, and may include or be fragments of a single layer or comprise an otherwise multi-layered or wrinkled or entangled arrangement, or a combination of all the aforementioned. These graphene sheets andcarbon nanotubes may all be of the same size and molecular mass, or may comprise a variety of sizes and molecular masses. Graphene sheets and carbon nanotubes follow a general formula 0fCn.

[0043] Graphene oxide is a two-dimensional carbon nanomaterial. It consists of a single atomic layer of carbon atoms with oxygen-containing functional groups attached to its surface and edges. These oxygen groups, which include epoxy, hydroxy, and carboxylic acid groups, make graphene oxide highly distinctive from pure graphene.

[0044] Nanodiamonds, also known as diamond nanoparticles, are diamond structures with sizes below 100 nanometers. These nanoscale diamond particles possess unique properties that make them valuable for various applications in nanotechnology, materials science, and biomedical research.

[0045] In an embodiment the fullerene is represented by the formula Cnwith n = 60 to 100, wherein the fullerene is preferably, a Ceo, C70, C72, C74, Cso, Cs2 or Cs4 fullerene.

[0046] Fullerenes are spherical cages made of carbon atoms with a general formula of Cn, wherein n is an even number that can vary from 20-540. The fullerenes may include or may be configured as Ceo fullerenes (Buckminster fullerenes) or as higher molecular weight fullerenes such as C70, Cs4, etc. Ceo is composed of 60 carbon atoms ordered in 12 pentagons and 20 hexagons and defining a carbon complex structure (carbon cage). Fullerenes having the above-described configuration are particularly stable, wherein Ceo, C70 and Cs4 show the greatest stability. An especially preferred fullerene within the context of the invention is the Buckminster fullerene (C6o).

[0047] In embodiments of the invention comprising a plurality of fullerenes within a single molecule, the constituent fullerenes may comprise fullerenes of the same molecular mass or may comprise a mixture of different fullerenes of different molecular masses.

[0048] Moreover, the fullerenes may include or may be configured as endohedral fullerenes. Endohedral fullerenes are fullerenes that have one or more additional particles (e.g., atoms, ions, molecules) enclosed within the carbon cage. The particles enclosed within the carbon cage are referred to as dopants. The dopants may comprise one or more of metal dopants, semimetal dopants, or their respective oxides, chlorides, fluorides, iodides, or nitrates. Exemplary dopants include one or more of: aluminium, antimony, barium, cerium, copper, didymium, gold, iron, lead, magnesium, molybdenum, neodymium, nickel, niobium, palladium, platinum, potassium,praseodymium, silicon, silver, tin, titanium, tungsten, vanadium, zinc and zirconium, as well as their respective oxides, chlorides, fluorides, iodides and nitrates. In embodiments of the invention comprising a plurality of fullerenes within a single molecule, the constituent fullerenes may be all comprise endohedral fullerenes, which in turn may be all comprise endohedral fullerenes containing the same dopant. Alternately, the constituent endohedral fullerenes may comprise combinations of different dopants. In embodiments of the present disclosure comprising a plurality of fullerenes within which there are endohedral fullerenes, some of the fullerenes may not contain any dopants.

[0049] It is further conceivable within the scope of the invention that the fullerene is an endohedral fullerene preferably selected from the group consisting of endohedral metallofullerene (EMF) such as mono-EMFs, di -EMF s, and cluster-EMFs; non-metal doped fullerene such as He@Ceo, Ne@Ceo, N@Ceo, N@C?o and P@Ceo; and molecular endofullerenes containing small molecules such as H2@Ceo, H20@Ceo, and CH4@Ceo.

[0050] In an alternative embodiment the carbon nanotube is a single-walled carbon nanotube (SWCNTs) or a multi-walled carbon nanotube (MWCNTs).

[0051] SWCNTs consist of a single layer of graphene rolled into a cylinder, with diameters typically ranging from 0.5 to 2.0 nm, whereas MWCNTs are composed of multiple concentric layers of graphene tubes, with diameters ranging from 2 to 100 nm.

[0052] SWCNTs have a higher surface area-to-volume ratio compared to MWCNTs, making them more suitable for applications in which a higher surface is beneficial. In general, both types are extremely strong, wherein MWCNTs are generally stronger and have a higher aspect ratio than SWCNTs. On the other hand, SWCNTs are highly flexible and elastic, with exceptional tensile strength.

[0053] In a further alternative embodiment, the carbon nanotube is an encapsulated CNT; a doped CNT such as nitrogen-, boron-, or phosphorus-doped CNT; an armchair CNT; a zigzag CNT or a chiral CNT.

[0054] Having CNTs of the above-described configuration may increase the overall stability, such as thermal or mechanical stability, and may further expand the use in biomedical applications.

[0055] It may be provided that the carbon nanotube has a length from 5 nm to 500 nm, preferably a length of 10 to 250 nm and more preferably a length from 50 to 150 nm.In a further alternative embodiment, the graphene is a monolayer graphene or a multilayer graphene. The monolayer graphene or a multilayer graphene has preferably a size of between 400 nm to 1000 m.

[0056] While monolayer graphene provides a higher surface area accompanied by better flexibility, multilayer graphene may provide increased mechanical strength. Moreover, by adjusting the number of the layers the properties of multilayer graphene may be fine-tuned according to the intended use.

[0057] It may be provided that the graphene is selected from the list consisting of exfoliated graphene, chemical vapor deposition graphene, graphene synthesized by chemical reduction of graphene oxide, liquid-phase exfoliated graphene and epitaxially grown graphene.

[0058] It is further conceivable within the scope of the invention that the cationic quaternary ammonium group has the formula RIR2R3R4N+X',

[0059] wherein Ri, R2, R3 and R4 represent, independently a substituted or unsubstituted and / or straight chain or branched and / or interrupted or uninterrupted alkyl, aryl, alkylaryl, arylalkyl, cycloalkyl, heterocyclyl or alkenyl group or two or more Ri, R2, R3 and R4 together with the nitrogen atom form a substituted or unsubstituted heterocyclic ring, and wherein the total number of carbon atoms in the groups Ri, R2, R3 and R4 is at least 4;

[0060] wherein the substituents for the groups Ri, R2, R3 and R4 are selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, heterocyclyl, substituted heterocyclyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl, F, Cl, Br, I, -OR', -NR’R” -CF3, -CN, -NO2 ,-C2R’, -SR’, -N3, -C(=O)NR’R”, -NR”C(=O)R", -C(=O)R’, -C(=O)OR’, -OC(=O)R’, -O(CR’R”)rC(=O)R’, -O(CR’R”)rNR”C(=O)R’, -O(CR’R”)rNR”SO2R’, -OC(=O)NR’R”, -NR’C(O)OR”, -SO2R’, -SO2NR’R”, and -NR’SO2R”;

[0061] wherein R’ and R” are individually hydrogen, C1-C12 alkyl, cycloalkyl, heterocyclyl, aryl, or arylalkyl, and r is an integer from 1 to 6, or R’ and R’ ’ together form a cyclic functionality; wherein the term "substituted" as applied to alkyl, alkenyl, heterocyclyl, cycloalkyl, aryl, alkylaryl and arylalkyl refers to the substituents described above, starting with F and ending with -NR’SO2R”;

[0062] wherein X' is a halide anion, a hydrogen sulphate anion, a sulphate anion, hydroxide anion, bicarbonate anion, carbonate anion, a carboxylate anion containing up to 18 carbon atoms, lactate anion, tartrate anion, gluconate anion, saccharinate anion, an alkanesulfonate anion, anarenesulphonate anion, phosphate ion, hydrogen phosphate ion, or dihydrogen phosphate ion, or a mixture of two or more of these ions;

[0063] and wherein for attachment to the carbon nanoparticle one of the following is given:

[0064] (a) one of Ri, R2, R3 and R4 is the carbon nanoparticle, and preferably a fullerene, or

[0065] (b) one or two of Ri, R2, R3 and R4 further contain a - preferably terminally located - functional group for covalent bonding of the respective R1-4 to the carbon nanoparticle by (i) establishing a direct covalent bonding of the respective R1-4 to the carbon atom of the carbon nanoparticle, or by (ii) establishing a covalent bonding to a linker for indirect coupling to the carbon atom of the carbon nanoparticle.

[0066] The above-mentioned highlights the great versatility of molecules which may solve the underlying problem of the state of the art.

[0067] Notably, two different configurations of the carbon nanotube may be achieved by the above. In a first configuration (see (a) above) the carbon nanoparticle is directly bonded to the nitrogen of the quaternary ammonium, whereas in the second configuration the nitrogen of the quaternary ammonium is indirectly bonded to the carbon nanoparticle via a residue as defined above of wherein the respective residue is further covalently bonded to a linker providing for an indirect coupling.

[0068] The second configuration (see (b) above) provides for a possibility to alter the physiochemical properties of various aspects and embodiments of the present invention and to circumvent issues of steric hindrance which may limit how many ammonium salts or quaternary ammonium groups can be bonded to a single carbon nanoparticle.

[0069] Of note, the second configuration (see (b) above) may further be divided in a first form where one or two of Ri, R2, R3 and R4 further contain a - preferably terminally located - functional group for covalent bonding of the respective R1-4 to the carbon nanoparticle by establishing a direct covalent bonding of the respective R1-4 to the carbon atom of the carbon nanoparticle. In the second form one or two of Ri, R2, R3 and R4 further contain a - preferably terminally located - functional group for covalent bonding of the respective R1-4 to the carbon nanoparticle by establishing a covalent bonding to a linker for indirect coupling to the carbon atom of the carbon nanoparticle.In another embodiment, the functional group of the one or two of Ri, R2, R3 and R4 can be used to establish a direct covalent bonding of the respective R1-4 to a polymer matrix or resin matrix in order to incorporate the functionalized carbon nanoparticle into the polymer or resin matrix. Whilst there is no particular limitation to the nature or constitution of the residue binding to the carbon nanoparticle according to the second configuration (see (b) above) besides steric or toxicological constraints, particularly preferable is the use of organic groups that include, but are not limited to, carbonyls, carbonates, esters, ethers, epoxides, sulphoxides, thiocarbonates, thioesters, dithioesters, thioethers, episulphides, thioketones, urethanes, thiourethanes, amines, amides, imides, enamines and sulphones. Where the invention relates to a plurality of ammonium salts or quaternary ammonium groups bonded to the carbon nanoparticle by way of a plurality of linkers, the constituent linkers may comprise linker of the same molecular structure or composition, or may comprise a mixture of different linkers of different molecular structures or compositions.

[0070] It should further be noted, that depending on configuration the overall chemical composition or molecular weight of the carbon nanoparticle may be altered, thereby allowing for the possibility to fine-tune the physiochemical properties according to the intended use.

[0071] Moreover, it is possible to have a plurality of residues or a plurality of ammonium salts or quaternary ammonium groups which may be arranged in such a manner as to comprise a plurality of residues or ammonium salts or quaternary ammonium groups anchored by a single bond to one or a plurality of carbon nanoparticles.

[0072] Long, high molecular-weight substituents may exhibit poorer solubility or dispersibility in aqueous or polar media if a small percentage of their molecular mass comprises ammonium salts or quaternary ammonium groups or if a large percentage of their molecular mass comprises hydrophobic linker, but may exhibit excellent solubility or dispersibility in oily or hydrophobic media.

[0073] For example, FIG. 1 shows an embodiment of the present invention that has a polymerized linker comprising polyethylene glycol, which is an amphiphilic material, and that is capped by a polarized end comprising the quaternary ammonium group linked to the linker via an ester. This embodiment may, dependent upon the length of the polyethylene glycol chains, have a high molecular weight, but due to its amphiphilic chain and highly polarized ends combined with its hydrophobic core, will exhibit excellent surfactant and antimicrobial properties.On the other hand, substituents comprising a high percentage of their mass as ammonium salts or quaternary ammonium groups may exhibit excellent dispersibility or solubility in aqueous or polar media, and may be additionally beneficial as the quaternary ammonium group allows the invention to be incorporated stably into a polyester or polyurethane.

[0074] For example, FIG. 2 shows an example of such an embodiment of the present disclosure, which can contain a number of ammonium salts or quaternary ammonium salts that is excessive for incorporation into cosmetics or for medical uses, but is excellent for incorporation into polymers.

[0075] A combination of the aforementioned factors means that various embodiments of the present invention can have vastly different degrees of hydrophobicity, hydrophilicity and great variabilities in molecular weight. This means that depending on the parameters used, the carbon nanoparticle of the invention will exhibit differing degrees of solubility, dispersibility, stability and surfactant and antimicrobial efficacy under different conditions.

[0076] For example, a high solubility and effectiveness in oil-in-water (OIW) emulsions may be achieved when the value m of FIG. 3 is from 4 - 12, whereas a high solubility and effectiveness in water-in-oil (WIO) emulsions maybe achieved when the value m of FIG. 3 is from 24 - 50. Additionally, it may be even more effective when incorporated into a polymer (see Example 5).

[0077] The counterions which accompany the ammonium salts or quaternary ammonium groups are anionic in nature. Whilst there is no particular limitation to the nature or constitution of the counterion besides steric or toxicological constraints, particularly preferable counterions for use in the present invention include, but are not limited to, halides (F‘, CF, Br, T), sulphates (SCU2' and HSOF), nitrate (NO3 ), hydroxide (OH"), carbonates (CCh2-and HCO3 ) and acetate (CH3COO ). Larger and more complex organic counterions, including but not limited to citrate and benzoate are also suitable. In embodiments of the invention comprising a plurality of ammonium salts or quaternary ammonium groups, the counterions accompanying the ammonium salts or quaternary ammonium groups may comprise counterions of the same composition, or may comprise a mixture of different counterions of different compositions.

[0078] It may further be provided that the cationic quaternary ammonium group has the formula (CH3)n(A)mN+X‘, wherein each A is independently as defined for Ri, R2, R3 and R4, n is from 1 to 3 and m is from 1 to 3 provided that the sum of n and m is 4.Of note, the above-mentioned formula shows a cationic quaternary ammonium group without providing a functional group. In other words, the formula relates to the "unfunctionalized" version. However, the person skilled in the art is aware that, to be in conformity with variant (b) of the embodiment above, the group A needs to have a, preferably terminally located, functional group for covalent bonding to the carbon nanoparticle. As such, and with respect to variant (b) that requires a functional group in at least one of the residues, it is self-evident for the skilled person that the formula above merely illustrates the basic framework of the quaternary ammonium group. In other words, in the above formula, group A may contain a functional group. This applies also for all further embodiments referring to the formula hereinabove.

[0079] In an embodiment each A is independently a Ce-20 substituted or unsubstituted and / or straight chain or branched and / or interrupted or uninterrupted alkyl, aryl, alkylaryl, arylalkyl or cycloalkyl group.

[0080] This embodiment corresponds to the above-mentioned first form of the second configuration (b), i.e., where the residue is bound to the carbon nanoparticle as well as the nitrogen of the quaternary ammonium.

[0081] In another embodiment the cationic quaternary ammonium group is selected from propyltrimethylammonium bromide, Cetrimide, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide.

[0082] This embodiment relates to the above-mentioned formula, where n is 3 and m is 1. As such the cationic quaternary ammonium group is a trimethylammonium group having varying groups of A.

[0083] In a further embodiment the carbon nanoparticle is a fullerene, preferably a Ceo fullerene, the cationic quaternary ammonium group is propyltrimethylammonium bromide, and the number of cationic quaternary ammonium groups per fullerene is from n = 6 - 12 or from n = 12 - 24.

[0084] A simplified illustration may be seen in FIG. 5, wherein only one substituent is shown. Moreover, reference is made to Examples 2 and 3. These two carbon nanoparticles corresponding to this embodiment show signs of toxicity only at high concentrations.It is further conceivable within the scope of the invention that n = 2 and m = 2 and each A is the same or different and is a straight chain, unsubstituted and uninterrupted Cs-12 alkyl group or a benzyl group.

[0085] In an alternative embodiment the cationic quaternary ammonium group is a benzalkonium halide or an aryl ring substituted derivative thereof.

[0086] It may further be provided that the benzalkonium halide has the formula:

[0087]

[0088] wherein R is as defined for Ri, R2, R3 and R4.

[0089] It may further be provided that R is a Cs-is alkyl group or a mixture of Cs-18 alkyl groups, preferably when the benzalkonium halide has the formula provided hereinabove.

[0090] In the embodiment hereinabove it may further be preferred that R is a mixture of straight chain, unsubstituted and uninterrupted Cs-18 alkyl groups.

[0091] It is further within the scope of the invention that one or more of Ri, R2, R3 and R4 is an alkyl, aryl, alkylaryl, arylalkyl or cycloalkyl group interrupted by a heteroatom selected from oxygen, nitrogen, sulphur, and a phosphorus-containing moiety.

[0092] Interruption by a heteroatom means that any carbon atom of an alkyl, aryl, alkylaryl, arylalkyl or cycloalkyl group mentioned above may be substituted by an oxygen, nitrogen, sulphur, or a phosphorus-containing moiety. It is also conceivable that the group is interrupted more than once.

[0093] In a further embodiment the cationic quaternary ammonium group is selected from the group consisting of domiphen bromide, benzethonium chloride, benzyldimethyl-n-tetradecyl-ammonium chloride, benzyldimethyl-n-dodecyl-ammonium chloride, n-dodecyl-n-tetradecyldimethyl-ammonium chloride and benzyl-Ci2-Ci6-alkyl-dimethyl-ammonium chloride, benzyl-cocoalkyl-dimethyl-ammonium chloride, di-n-decyldimethyl-ammonium chloride, bridged cyclic amino compounds such as the hexaminium compounds, cetalkonium chloride, cetylpyridinium chloride, glycidyl trimethyl ammonium chloride stearalkonium chloride, zephiran chloride, diisobutylphenoxyethoxyethyl-dimethylbenzylammoniumchloride, N-Benzyl-N,N-dimethyl-N-[4-(l .1.3.3 -tetramethylbutyl)-phenoxy ethoxy ethyl] ammonium chloride, cetalkonium chloride, cetyldimethylbenzylammonium chloride, cetyltrimethylammonium bromide, 1-hexadecylpyridinium chloride, glycidyltrimethyl-ammonium chloride, benzethonium chloride CAS 121-54-0, cetalkonium Chloride CAS 122-18-9, cetrimide CAS 8044-71-1, stearalkonium chloride CAS 122-19-0, cetrimonium bromide CAS 57-09-0, benzalkonium chloride, phenyltrimethylammonium chloride, phenyltrimethylammoniuim iodide, benzyldimethyl-hexadecylammonium chloride, phenylbenzylammonium chloride, 4, 4‘-bipyridinium-l,r -dimethyl di chloride (paraquat), dibromide, diiodide, 2,2‘-bipyridinium-l,r-dimethyl dichloride, dibromide and diiodide, 4,4‘-bipyridinium-l,r -dibenzyl dichloride, dibromide and diiodide, and mixtures thereof.

[0094] It may also be provided that the carbon nanoparticle is derivatized with a combination of at least two different cationic quaternary ammonium groups.

[0095] An increased number of cationic quaternary ammonium groups may provide the carbon nanoparticle with an overall increased polarity, thereby increasing the solubility in polar solvents such as water. Additionally, an increased number of quaternary ammonium groups results in an enhanced antimicrobial activity, although excessive amounts of quaternary ammonium groups may be detrimental with respect to both surfactant activity and toxicity.

[0096] By derivatizing the carbon nanoparticle with different quaternary ammonium groups, the effects of the respective ammonium groups may be added or even work in a synergistic matter.

[0097] In another embodiment the linker comprises straight-chain saturated or unsaturated hydrocarbons from 1-30 atoms, branched-chain saturated or unsaturated hydrocarbons from 1-30 atoms, cyclic or polycyclic aliphatic hydrocarbons from 5-30 atoms, homocyclic or heterocyclic aromatic hydrocarbons comprising from 5-10 atoms in their ring(s).

[0098] This embodiment refers to the second configuration and the second form thereof, i.e., in which a linker is provided to indirectly couple the ammonium or quaternary ammonium group to the carbon atom of the carbon nanoparticle.

[0099] In using a linker according to the above embodiment, the physiochemical properties of the carbon nanoparticle may be altered. For example, to circumvent issues of steric hindrance which may limit how many ammonium salts or quaternary ammonium groups can be bonded to a single carbon nanoparticle.In a further embodiment one or a plurality of the hydrocarbons of the linker contains one or more substituents comprising non-carbon atoms, including nitrogen, oxygen, sulphur, silicon, fluorine, chlorine, bromine and iodine.

[0100] In another further embodiment the linker is a polymeric linker.

[0101] A polymeric linker is a linker that comprises repeated monomer subunits. In other words, the polymeric linker is a polymeric chain. However, it may also be feasible that the polymeric linker contains other subunits that do not form polymers next to the polymeric chain.

[0102] In using a polymeric linker, the molecular weight of the carbon nanoparticle may be increased in a convenient way. The molecular weight influences the physicochemical properties of the carbon nanoparticle.

[0103] Where the carbon nanoparticle of the present invention comprises a plurality of linkers or a plurality of ammonium salts or quaternary ammonium groups bound to one or a plurality of carbon nanoparticles, these may be arranged as copolymers, such as random copolymers, alternating copolymers, block copolymers or graft copolymers.

[0104] Where a plurality of polymeric linkers is used, it is feasible that the polymer chains may be of the same molecular structure or composition, or may be of different molecular structures or compositions.

[0105] In an embodiment where the polymer is arranged as a graft copolymer, the ammonium salts or quaternary ammonium groups are most preferably located primarily in the side chains or branches. This maximizes the surfactant and antimicrobial properties of the carbon nanoparticle.

[0106] Additionally, one or a plurality of the polymer chains may comprise different ratios of ammonium salts or quaternary ammonium groups to the linker in order to achieve different physiochemical properties and different levels of antimicrobial or surfactant activity.

[0107] It may also be provided that that the polymeric linker is a linear polymeric linker which is preferably selected from the group consisting of a polyether, methoxy polyethylene glycol (mPEG), a polyacrylate, a polyanhydride, a polyvinyl alcohol, a polysaccharide, a poly(N-vinylpyrrolidone), a polyglycerol (PG), a poly(N-(2-hydroxypropyl)methacrylamide, a polyoxazoline, a poly(amino acid)-based hybrid, a polyamide, preferably a recombinantpolypeptide, a polyester, a polythioester, a polyurethane, a polythiourethane, derivatives, and combinations thereof.

[0108] A linear polymeric linker provides for high flexibility of the linker, thereby allowing for an overall less rigid structure of the inventive carbon nanoparticle.

[0109] In a further embodiment, the linear polymeric linker is a polyethylene glycol of the formula:

[0110]

[0111] wherein q is an integer of 1 to 1000, preferably q = 2 to 800, more preferably q = 50 to 600, and even more preferably q = 80 to 400.

[0112] By using a polyethylene glycol as described above it is possible to adjust the water-solubility of the inventive nanoparticle. Moreover, polyethylene glycol generally shows non to very low toxicity and is non-irritating to skin. Furthermore, it is not readily biodegradable and as such may be used in applications where the bio-stability of the inventive carbon nanoparticle has to be ensured. For example, in cosmetic or pharmaceutical compositions.

[0113] It may further be provided that the linear polymeric linker is a linear bifunctional polymeric linker having two functional / reactive groups on the two ends of said linear polymer, wherein exemplary functional groups include, but are not limited to, the following: a hydroxyl, a carboxyl, a thiol, an amine, a phosphate, a phosphonate, a sulfate, a sulfite, a sulfonate, a sulfoxide, a sulfone, an amide, an ester, a ketone, an aldehyde, a cyano, a thiocyano, an alkyne, an azide, and an alkene, or a combination thereof.

[0114] By having a bifunctional polymeric linker, the manufacturing process of the carbon nanoparticle is simplified.

[0115] In another embodiment the quaternary ammonium salt polymer is prepared by introduction of a quaternary nitrogen in a given polymer by one of the following ways of quatemization: (a) Quatemization of a halogen containing polymer with a tertiary amine,

[0116] (b) Quatemization of a polymeric tertiary amine with an alkyl or aryl halide,(c) Base-catalysed Mannich reaction of a polymeric amide with formaldehyde and dimethylamine followed by quaternization,

[0117] (d) Quaternization of polymers containing OH-groups by appropriate agents such as 2,3- epoxypropyl trim ethyl ammonium chi ori de .

[0118] Quaternary ammonium salt polymers are water-soluble, have a good chemical stability and an adjustable cationicity. Quaternary ammonium salt polymers are valued for their versatility, efficiency, and relatively low toxicity in various industrial and consumer applications.

[0119] Several reactions may be used to arrive at quaternary ammonium salt polymers, each with its specific advantages. One of the most common methods is the Menshutkin reaction, which involves the alkylation of a tertiary amine with an alkyl halide.

[0120] The advantage for quaternary ammonium salt polymer is that, due to their ability to contain multiple QACs in a single substituent chain, a much lower degree of substitution on the fullerene can result in significantly stronger surfactant and antimicrobial effects, and better preservation of the fullerene’s antioxidant capability.

[0121] In an alternative embodiment the quaternary ammonium salt polymer is a homopolymer or copolymer made by use of a monomer containing a cationic quaternary ammonium group, whereby said monomer is preferably selected from the group consisting of diallyl dimethyl ammonium chloride (DADMAC), 3 -chi oro-2 -hydroxypropyl methyl diallyl dimethyl ammonium chloride (CMDA), acryloyl oxygen ethyl trimethyl ammonium chloride (DAC), methyl acryloyl oxygen ethyl trimethyl ammonium chloride (DMC), acrylamide propyl trimethyl ammonium chloride (APTAC), methyl acrylamide propyl trimethyl ammonium chloride (MAPTAC), N,N-dialkyl-N-2(alkoxycarbonyl)allyl-N-allylammonium chloride, N,N-diallylpyrrolidinium bromide, N,N-diallylisoquinolinium chloride and N,N-diallylmorpholinium bromide.

[0122] In a further embodiment the quaternary ammonium salt polymer is a homopolymer selected from the group consisting of poly-DADMAC, poly-DAC, poly-DMC, poly-APTAC, poly-MAPTAC or a copolymer with acrylamide (AM) as further monomer such as poly(DMD AAC-AM), poly(DAC-AM), poly(DMC-AM), poly(APTAC-AM) and poly(MAPTAC-AM).

[0123] In another embodiment the quaternary ammonium salt polymer is a linear polymer, a crosslinked polymer, a branched polymer or a network-forming polymer.In a second aspect the invention relates to the carbon nanoparticle for use as an antimicrobial agent, surfactant, stabilizing agent, or preservative.

[0124] The present invention shows excellent antimicrobial effects and as such may be used for varying applications, such as the treatment or prevention of infectious diseases, other non-infectious medical applications, disinfection and sterilization as well as agricultural use.

[0125] The present invention also exhibits surfactant properties due to the presence of hydrophobic components of the molecule in the form of the carbon nanoparticle without any substituents, and hydrophilic components of the molecule in the form of ammonium salts or quaternary ammonium groups attached to the carbon nanoparticle. Additional hydrophobic or hydrophilic groups can be added in the form of the functional groups bonded directly to the carbon nanoparticle, or in the form of the linker. The hydrophile / hydrophobe balance and molecular weight within any given embodiment of the invention can be controlled via adjustment of one or a plurality of synthetic parameters, as is described in this disclosure through both general description and examples.

[0126] When used as a surfactant, the inventive carbon nanoparticle may be formulated as solutions, suspensions and emulsions having between 0.01%-40% by weight of the inventive carbon nanoparticle in the total formulation, but most preferably between 0. l%-5% by weight of the inventive carbon nanoparticle in the total formulation.

[0127] To form the aforementioned solutions, suspensions or emulsions suitable mechanical agitation or homogenization may be required, with specific dosages of the inventive carbon nanoparticle as well as other materials, including but not limited to co-surfactants and active ingredients. One or a plurality of embodiments of the present invention may be used concurrently in any given formulation. For example, a primarily aqueous suspension of the present invention as an OIW emulsion for oral application can be prepared by dispersing a suitable embodiment of the present invention in an edible oily medium, such as olive oil or glyceryl laurate, then mixing or homogenizing it in water with other various ingredients such as flavoring agents, colorants and thickening agents.

[0128] In addition, the inventive carbon nanoparticle may be more generally used as a preservative or antimicrobial additive due to its properties laid out above. In these cases, the inventive carbon nanoparticle ranges between 0.01%-40% by weight of the inventive carbon nanoparticle in thetotal formulation, but most preferably between 0.1%-5% by weight of the inventive carbon nanoparticle in the total formulation.

[0129] To form the aforementioned formulations or preparations suitable mechanical agitation or homogenization may be required, with specific dosages of various embodiments of the present invention as well as other materials, including but not limited to emulsifiers, colorants, perfumes, conditioners, thickening agents, foaming agents and active ingredients.

[0130] For example, a cosmetic cream containing the inventive carbon nanoparticle as a preservative can be prepared by dispersing or homogenizing it within the phase of the formulation within which it is most easily dispersed (this depends on the embodiment of the invention, for example a primarily hydrophilic embodiment will be most easily dispersed in the aqueous phase of the formulation prior to the addition of hydrophobic ingredients), then mixing or homogenizing the aforementioned phase of the formulation with the other various ingredients such as oils, waxes and emulsifiers.

[0131] Various embodiments of the present invention can be dissolved or dispersed in a solvent in order to more readily mix them as solutions or suspensions for integration into another material, whether as an eventual bonded component of the material or as a component that is part of a larger composite. Any given application of the invention may use a single embodiment of the present invention or a combination of multiple embodiments. Therefore, because of the nanoscale size of various embodiments of the present invention, as well as their variable solubilities in various polar and non-polar solvents, terms such as “dissolve”, “disperse” and “suspend” may be used herein interchangeably, as can be “solution”, “dispersion” and “suspension”, as in some cases it is not readily apparent that for the liquid phase employed whether a suspension or a true solution has been formed. In some embodiments and applications of the present invention, as is known to one skilled in the art, a dispersion and solution are distinct states.

[0132] In a third aspect the invention relates to the inventive carbon nanoparticle for use as an antimicrobial agent in the treatment or prevention of an infectious disease in a mammal.

[0133] Due to its antimicrobial effect the inventive carbon nanoparticle is suited to treat infectious diseases or prevent them, when administered beforehand. A mammal in the sense of the application may be any mammal, preferably a horse, cat, dog, mouse, rat, rabbit or a human, whereas the mammal is most preferably a human.Examples of infectious diseases suitable to be treated or prevented with the inventive carbon nanoparticle are summarized in class 1 of the ICD-11 classification as well as "certain skin disorders attributable to infection or infestation (EA00-EA6Y)" of class 14.

[0134] The inventive carbon nanoparticle may be administered locally, such as an ointment or a cream, or it may be administered systemically by way of oral intake, intraperitoneal, intravenous, subcutaneous or other injection, wherein local administration is preferred.

[0135] It is self-evident that the inventive carbon nanoparticle may be used in a combination therapy with other treatment paradigms to achieve added or even synergistic effects.

[0136] For the use as antimicrobial agent, it is preferred that the functionalized carbon nanoparticle contains sterically unhindered QAC groups (these are usually terminal if polymers are being used).

[0137] In another embodiment, it is preferred to use a functionalized carbon nanoparticle having a high surfactant activity, which is generally obtained by a middle / lower degree of substitution on the carbon nanoparticle (being preferably a fullerene) for the hydrophobic component and QAC groups with a high charge / density ratio for the hydrophilic component.

[0138] In a further embodiment the infectious disease is caused by one or more of the following pathogens: bacteria, viruses, fungi, parasites or prions.

[0139] It may also be provided that the infectious disease is a skin infection or a soft tissue infection.

[0140] Examples for such diseases are summarized in as "certain skin disorders attributable to infection or infestation (EA00-EA6Y)" of class 14 of the ICD-11 classification. More specifically, the diseases may be any of simple abscesses, impetigo, folliculitis, furuncles and carbuncles, cellulitis, infected ulcers or bums, major abscesses, necrotizing fasciitis or diabetic foot infections.

[0141] In a further embodiment the infectious disease is a fungal skin infection.

[0142] In a fourth aspect the invention relates to the inventive carbon nanoparticle for use as an antimicrobial oral care composition for the treatment or prevention of a dental illness selected from the group consisting of plaque, caries, periodontal disease, gingivitis and breath malodor, or combinations thereof.The illnesses listed herein result from pathogen infections and, as such, may be treated or prevented by the inventive carbon nanoparticle.

[0143] In a fifth aspect the invention relates to a pharmaceutical composition comprising the inventive carbon nanoparticle and a pharmaceutically acceptable excipient.

[0144] The inventive carbon nanoparticle may be combined with a pharmaceutically-acceptable excipient into acceptable dosage forms for internal or external application to treat or prevent microbial infection. The pharmaceutical compositions of this embodiment display exceptionally low levels of toxicity or sensitization to human or animal cells relative to their toxicity towards pathogenic cells.

[0145] The inventive carbon nanoparticle may be incorporated into liquid pharmaceutical formulations as per the methods previously described for other applications, but can also be used as solid or semi-solid pharmaceutical formulations. Pharmaceutical formulations include but are not limited to sprays, ointments, creams, pastes, foams, drops, suspensions, solutions, injections, powder injections, suppositories, patches, capsules, granules, pills and powders.

[0146] To form the aforementioned pharmaceutical formulations, specific dosages of the inventive carbon nanoparticle are combined with other materials, including but not limited to encapsulating agents, release agents, solubilizes, binding agents, bulking agents and other active ingredients. For example, a powder pharmaceutical formulation can be prepared by dry powder milling the lyophilized inventive carbon nanoparticle with a suitable solid carrier such as magnesium carbonate, magnesium stearate or talc. If desired, this powder mixture can be pressed into a tablet or encapsulated within a capsule.

[0147] In a further embodiment the pharmaceutically acceptable excipient is selected from the list consisting of diluents / fillers, binders, lubricants, glidants, disintegrants, coating agents, suspending agents, preservatives, antioxidants, buffers, emulsifiers, solubilizers, stabilizers, flavoring agents and coloring agents.

[0148] It may further be provided that the pharmaceutical composition contains the carbon nanoparticle in a concentration of 0.1 to 100 wt.%, preferably 1 to 50 wt.% and more preferably 10-30 wt.% with respect to the total weight of the pharmaceutical composition.

[0149] In a sixth aspect the invention relates to an antimicrobial composition comprising the inventive carbon nanoparticle and a liquid carrier, wherein the carbon nanoparticle is solubilized ordispersed within the liquid carrier. In a preferred embodiment, the liquid carrier is selected from the list consisting of DMSO, pentylene glycol, propylene glycol, polyethylene glycol and ethoxy di glycol. These liquid carriers are excellent carriers for enabling skin penetration of larger active substances, and their amphiphilic nature makes them suitable for dispersing / dissolving various embodiments of the invention in the antimicrobial composition.

[0150] In a further embodiment the antimicrobial composition contains the carbon nanoparticle in a concentration of 1 to 50 wt.%, preferably 5 to 40 wt.% and more preferably 10 to 30 wt.%.

[0151] In a seventh aspect the invention relates to a cosmetic composition comprising 0.01 to 40 % by weight, preferably between 0.1 to 5.0 % by weight of the inventive carbon nanoparticle with respect to the weight of the cosmetic composition and a dermatologically acceptable carrier.

[0152] The inventive carbon nanoparticle is also useful in cosmetic formulations due to its combination of surfactant and antimicrobial properties, as cosmetic formulations are particularly vulnerable because they are subject to frequent contamination by pathogens found on the skin when applied by the user, and because they often have a high water content and are stored in warm conditions which combine to make them an excellent environment for pathogenic proliferation.

[0153] In an eight aspect the invention relates to a coating composition for providing an antimicrobial surface comprising the inventive carbon nanoparticle and a film-forming carrier, wherein the film-forming carrier is preferably a polymer or a resin.

[0154] The present invention exhibits antimicrobial activity and can be included in a coating to provide an antimicrobial surface. For example, the coating may comprise polymers and / or resins. There exist multiple methods of incorporation of the inventive carbon nanoparticle into the aforementioned polymers and resins to lend them persistent antimicrobial properties. When incorporated into a polymer or resin to lend it antimicrobial properties, an antimicrobially effective amount of the inventive carbon nanoparticle may be between 0.01%-25% by weight of the material, but most preferably between 0. l%-5%. One or a plurality of embodiments of the present invention may be used concurrently in any given polymer or resin.

[0155] By using the inventive carbon nanoparticle, it is not only antimicrobially effective, but is also reasonably mechanically and chemically stable. Moreover, exhaustion by either repeated touching or abrasion or via their method of antimicrobial action is reduced or even entirely prevented.For the creation of thermoplastic composites, various general techniques are known to the skilled person, including but not limited to dry powder milling wherein the inventive carbon nanoparticle is mixed with thermoplastic powder or pellets which is then melted and extruded into a mold, wet mixing or homogenizing into melted thermoplastic above its melting point or dissolution or dispersion of the inventive carbon nanoparticle into a solvent containing dissolved thermoplastic from which the solvent is evaporated.

[0156] For the synthesis of a thermoplastic in which the inventive carbon nanoparticle is a copolymer, the inventive carbon nanoparticle must have at least one or more functional groups either bonded directly to the carbon nanoparticle or as the terminal functional groups on one or more quaternary ammonium groups or polymeric linker, which can react with another monomer. For example, for incorporation as part of polyamide the aforementioned functional group must be a carboxylic acid, acyl halide or primary amine.

[0157] For the incorporation into a resin, whether as a composite or copolymer, the same techniques of wet mixing or homogenization is most preferable, with the key differences between the two processes being the nature of the inventive carbon nanoparticle and the reaction conditions, the former in the form of suitable compatible functional groups for polymerization, the latter in the form of special reaction requirements for some polymerization reactions. For example, for polymerization into a polyurethane the homogenization is preferred to take place in an inert atmosphere or vacuum and in the absence of moisture.

[0158] Once the inventive carbon nanoparticle has been incorporated into a polymer or resin by the aforementioned or other techniques, this polymer or resin can be cast or molded directly into the shape desired by the end user. More preferably, for reasons of economy and practicality, the polymer or resin can be applied as a coating or film over a variety of substrates, such as metals, glasses, plastics, ceramics or paints or other pre-treatment coatings. Various methods of applying this coating or film include but are not limited to wiping, brushing, casting, dipcoating, spin-coating or spraying.

[0159] Whilst there is no particular limitation to the areas or devices as substrates upon which the coatings containing the inventive carbon nanoparticle are applied, in some embodiments, this substrate may be worn on the human body (e.g. surgical masks, gloves, gowns etc.) or may be applied to all or part of an object, with special preference to substrates that will be subject to frequent touching or other source of contamination (e.g. handles, valves, knobs, dials, buttons, supporting or working surfaces etc.). In some embodiments where the inventive carbonnanoparticle is incorporated into the surfaces of medical devices, the substrate may be the surface of an implant such as a pacemaker, artificial joint, stent, coil or other implantable device. In a particularly preferable embodiments, it is incorporated into the surface of porous media, thereby preventing the proliferation of undesirable microorganisms within or on the porous media, especially when it is used as a filter.

[0160] In a ninth aspect the invention relates to an antimicrobial device comprising a polymer or resin that contains the inventive carbon nanoparticle.

[0161] In one embodiment, the QAC or QAC polymer group of the functionalized carbon nanoparticle contains a terminal functional group for binding said carbon nanoparticle to the polymer or resin or even provides a monomer for generating said polymer or resin. In the latter embodiment, it exists effectively as a copolymer or crosslinking agent rather than as part of a composite. The terminal functional groups are preferably selected from the group consisting of hydroxyl groups, alkoxy groups, aryloxy groups, carbonyl groups, carboxyl groups, epoxide groups, thiol groups, alkyl and aryl sulphide groups, sulphoxide groups, sulphone groups, sulphonyl groups, sulphonamide, thioureas, amines, hydroxylamines, nitriles, nitro groups, cyano groups, N-oxides, hydrazides, azides, enamines and urea groups.

[0162] In an embodiment of the invention the polymer or resin contains the inventive carbon nanoparticle in an amount of 0.01 to 25 % by weight, preferably between 0.1 to 5.0 % by weight with respect to the total weight of the polymer or resin combined with the inventive carbon nanoparticle.

[0163] In a further embodiment the antimicrobial device is a medical device and preferably selected from the group consisting of syringes, catheters, stents, abdominal plugs, cotton gauzes, wound dressings, hemostatic materials, adhesive films, contact lenses, lens cases, bandages, sutures, hernia meshes, ostomy and other wound products and breast implants.

[0164] Generally, in subject-matter in which more than one molecule of the invention may be present, it is understood that said plurality of molecules are not necessarily identical molecules, but the molecules may differ from each other. In particular, different carbon backbones may be present side by side. For example, fullerene, graphene and nanotube. In particular, the substituents can also differ from one another. For example, fullerenes with two or more different substituent compositions can be present in one and the same subject-matter.

[0165] In a further aspect the invention relates to the Embodiments 1 to 5, as stated below:T1

[0166] Embodiment 1: A method for the prevention or treatment of an infectious disease, comprising the step of administering to a mammal in need of preventing or treating an infectious disease, a therapeutically effective amount of the inventive carbon nanoparticle.

[0167] Embodiment 2: The method according to embodiment 1, wherein the infectious disease is caused by one or more of the following pathogens: bacteria, viruses, fungi, parasites or prions.

[0168] Embodiment 3: The method according to embodiment 1 or 2, wherein the infectious disease is a skin infection or a soft tissue infection.

[0169] Embodiment 4: The method according to embodiment 3, wherein the infectious disease is a fungal skin infection.

[0170] Embodiment 5: A method for the prevention or treatment of a dental illness selected from the group consisting of plaque, caries, periodontal disease, gingivitis and breath malodor, or combinations thereof, comprising the step of administering to a mammal in need of preventing or treating a dental illness selected from the group consisting of plaque, caries, periodontal disease, gingivitis and breath malodor, or combinations thereof, a therapeutically effective amount of the inventive carbon nanoparticle as an oral care composition.

[0171] Further advantages, features and details of the invention will be apparent from the following description, in which embodiments of the invention are described in detail with reference to the figures.

[0172] The foregoing explanation of the embodiments describes the present invention exclusively in the context of examples. Of course, individual features of the embodiments can be freely combined with each other, provided that this is technically reasonable, without leaving the scope of the present invention.

[0173] Definitions

[0174] A / an: As used herein the specification, “a” or “an” may mean one or more. As used herein in the claim(s), when used in conjunction with the word “comprising,” the words “a” or “an” may mean one or more than one. It is self-evident that where the description relates formulations or something similar comprising the inventive carbon nanoparticle that it does not necessarily comprise only one specific molecule of the inventive carbon nanoparticle, but it may contain several molecules that differ from one another. For example, a pharmaceuticalcomposition may contain a fullerene having defined substituents, a graphene sheet having the same substituents and a fullerene having substituents that differ from the previous.

[0175] Or / and / or: The use of the term “or” in the claims is used to mean “and / or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.”

[0176] Quaternary ammonium compound / QAC: Quaternary ammonium compounds (QACs), also known as quats, are a class of chemical compounds characterized by a central nitrogen atom bonded to four organic groups, forming a positively charged cation. The general structure of QACs can be represented as [NEG] , where each R is selected individually from a hydrocarbon.

[0177] The term ammonium compounds as used in the context of the present invention is defined as a positively charged (protonated) substituted primary, secondary or tertiary amine as represented by the formulas [NR.H3] , [NR2H2]+,or [NR.3H] , respectively.

[0178] Quaternary ammonium salt polymer: The term "quaternary ammonium salt polymer" as used herein refers to cationic polymers having a quaternary ammonium moiety.

[0179] Functionalization / functionalized: The term "functionalization" as used herein refers to the process of introducing new functional groups or modifying existing ones on a molecule. A group, such as a carbon-hydrogen (C-H) bond, may be functionalized into other functional groups like C-C, C-N, or C-0 bonds. A functionalized molecule contains at least one functional group.

[0180] Aliphatic group: The term “aliphatic group” as used herein refers to a saturated or unsaturated linear or branched hydrocarbon group. This term is used to encompass alkyl, alkenyl and alkynyl groups, for example.

[0181] Alkyl / alkenyl / alk-: The terms “alkyl”, “alkenyl” and the prefix “alk-“ as used herein refer to be inclusive of substituted or unsubstituted, straight chain, branched chain and cyclic groups. Unless otherwise specified, these groups contain 1-30 carbon atoms. Where the aliphatic group is named, the naming follows standard chemical nomenclature, i.e., methyl, ethyl, propyl. Examples of alkyl groups include haloalkyl and hydroxyalkyl groups. The term “alkoxy” refers to an alkyl linked to a divalent oxygen. The term “alkylthio” refers to an alkyl linked to a divalent sulphur.Aryl / aromatic group: The terms “aryl” and “aromatic group” as used herein refer to aromatic hydrocarbon groups and heterocyclic aromatic groups. These groups can have from 5 to 10 atoms in their ring or rings, and includes fused ring compounds wherein at least one ring, but not necessarily all rings, are aromatic. Examples include benzyl, phenyl and naphthyl groups. An aryl can optionally be substituted, with the term “heteroaryl” or “heteroaryl group” used herein to refer to an aromatic heterocyclic group where at least one carbon atom is replaced with one or more of nitrogen, oxygen, sulphur or silicon. Where the aryl group contains one or more pendant groups, the naming follows standard chemical nomenclature, i.e., arylmethyl, arylethyl, arylpropyl etc. The term “aryloxy” refers to an aryl linked to a divalent oxygen. The term “arylthiol” refers to an aryl linked to a divalent sulphur.

[0182] Substituted / substituent: The terms “substituted” and “substituent” when used with reference to organic groups, describe one or more bonds of a hydrogen or carbon atom contained therein having been replaced by one or more bonds to a non-hydrogen or non-carbon atom. These include, but are not limited to, halogens, silicon-based groups, hydroxyl groups, alkoxy groups, aryloxy groups, carbonyl groups, carboxyl groups (including but not limited to carboxylic acids, carboxylates and carboxylate esters), sulphurated groups (including but not limited to thiol groups, alkyl and aryl sulphide groups, sulphoxide groups, sulphone groups, sulphonyl groups, sulphonamide, thioester, dithioester, thioether, thiourea and thiourethane groups) and nitrogen-containing groups (including but not limited to amines, hydroxyl amines, nitriles, nitro groups, cyano groups, N-oxides, hydrazides, azides, enamines, urea groups and urethanes). The term "substituent" with reference to the carbon nanoparticle is evident from the claims and description.

[0183] Surfactant / amphiphilic: The terms “surfactant” and “amphiphilic” are used herein for the purposes of this invention to refer to molecules that contain, within a single molecule, both hydrophobic and hydrophilic components which interact well with non-polar and polar substances respectively. The hydrophilic component of the molecule can be non-ionic, cationic, anionic or zwitterionic. The aforementioned terms “surfactant” and “amphiphilic” are also used herein for the purposes of this invention to refer to the properties of the aforementioned molecules.

[0184] Antimicrobial: The term “antimicrobial” is used herein for the purposes of this invention to refer to the general term or mechanism of the killing or inhibition of the growth or proliferation of microbial organisms, especially pathogenic microbial organisms. The microbialorganism may be any of bacteria, viruses, fungi, parasites or prions. With respect to bacteria, "antimicrobial" may refer to bacteriostatic or bactericidal actions.

[0185] Antimicrobially effective amount: The term “antimicrobially effective amount” as used herein refers to at least the minimum amount of a compound (e.g., the inventive carbon nanoparticle or a solution, dispersion or other formulation containing the inventive carbon nanoparticle) that elicits a desired antimicrobial response as defined hereinabove. This quantity or concentration depend on multiple variables, which include but are not limited to the chemical formula of the antimicrobial substance, the matrix in which it is embedded (if any) and the conditions in which it is expected to function.

[0186] Local administration / local delivery: As used herein, the term “local administration” or “local delivery”, in reference to delivery of compounds (such as therapeutic agents) described herein, refers to delivery that does not rely upon transport of said compounds to its intended target tissue or site via the vascular system. Said compounds described herein may be delivered directly to its intended target tissue or site, or in the vicinity thereof, e.g., in close proximity to the intended target tissue or site. For example, said compounds may be delivered by injection or by injection or implantation of a device containing the compounds. Following local administration in the vicinity of a target tissue or site, said compounds described herein, or one or more components thereof, may diffuse to the intended target tissue or site. It will be understood that once having been locally delivered a fraction of said compounds described herein (typically only a minor fraction of the administered dose) may enter the vascular system and be transported to another location, including back to its intended target tissue or site.

[0187] Systemic administration: As used herein, the term “systemic administration” and like terms are used herein consistently with their usage in the art to refer to administration of a compound (e.g., a therapeutic agent) such that the compound becomes widely distributed in the body in significant amounts and has a biological effect, e.g., its desired effect, in the blood and / or reaches its desired site of action via the vascular system. Typical systemic routes of administration include administration by (i) introducing the compound directly into the vascular system or (ii) subcutaneous, oral, pulmonary, intraperitoneal or intramuscular administration wherein the compound is absorbed, enters the vascular system, and is carried to one or more desired site(s) of action via the blood.

[0188] Subject: As used herein, the terms “subject”, “test subject” or “patient” refer to any organism to which a provided compound or composition is administered in accordance with thepresent invention e.g., for experimental, diagnostic, prophylactic, and / or therapeutic purposes. Typical subjects include animals (e.g., mammals such as mice, rats, rabbits, non-human primates, and humans; insects; worms; etc.) and plants. In some embodiments, a subject may be suffering from, and / or susceptible to a disease, disorder, and / or condition.

[0189] Effective / therapeutically effective amount: As used herein, the term “effective” or “therapeutically effective amount” means at least the minimum amount of a compound (e.g., a therapeutic agent, and / or formulation) that elicits a desired biological response when administered as part of a therapeutic regimen. In some embodiments, a therapeutically effective amount of a compound is an amount that is sufficient, when administered to a subject suffering from or susceptible to a disease, disorder, and / or condition, to treat, diagnose, prevent, and / or delay the onset of the disease, disorder, and / or condition. As will be appreciated by those of ordinary skill in this art, the effective amount of a compound may vary depending on such factors as the desired biological endpoint, the compound to be delivered, the target cell or tissue, etc. For example, the effective amount of compound in a formulation to treat a disease, disorder, and / or condition is the amount that alleviates, ameliorates, relieves, inhibits, prevents, delays onset of, reduces severity of and / or reduces incidence of one or more symptoms or signs of the disease, disorder, and / or condition. In some embodiments, a therapeutically effective amount is administered in a single dose; in some embodiments, multiple unit doses are required to deliver a therapeutically effective amount. A therapeutically effective amount may also be one in which any toxic or detrimental effects of the treatment are outweighed by the therapeutically beneficial effects.

[0190] Treatment / treating: “Treatment” or “ treating” includes (1) inhibiting a disease, disorder or condition in a subject or patient experiencing or displaying the pathology or symptomatology of the disease (e.g., arresting further development of the pathology and / or symptomatology), (2) ameliorating a disease, disorder or condition in a subject or patient that is experiencing or displaying the pathology or symptomatology of the disease (e.g., reversing the pathology and / or symptomatology), and / or (3) effecting any measurable decrease in a disease, disorder or condition in a subject or patient that is experiencing or displaying the pathology or symptomatology of the disease.

[0191] Combination therapy / in combination with: The term “combination therapy”, as used herein, refers to those situations in which two or more different compounds (e.g., a therapeutic agent and / or formulation) are administered in overlapping regimens so that the subject issimultaneously exposed to both compounds. When used in combination therapy, two or more different compounds may be administered simultaneously or separately. This administration in combination can include simultaneous administration of the two or more compounds in the same dosage form, simultaneous administration in separate dosage forms, and separate administration. That is, two or more compounds can be formulated together in the same dosage form and administered simultaneously. Alternatively, two or more compounds can be simultaneously administered, wherein the compounds are present in separate formulations. In another alternative, a first compound can be administered followed by one or more additional compounds. In the separate administration protocol, two or more compounds may be administered a few minutes apart, or a few hours apart, a few days apart, or a few weeks apart. In some embodiments, two or more compounds may be administered 1-2 weeks apart.

[0192] Synergism / synergistic effect: The terms “synergism” or “synergistic effect” refer to the combined effect of two or more compounds that is greater than the sum of the separate effects of the cancer compounds / therapies alone.

[0193] Brief description of the drawings

[0194] A better understanding of the present invention and its variants can be obtained upon review of the detailed description together with the accompanying drawings and examples. It should be noted that the scope of the present invention is not limited to the drawings and examples described below and various modifications may be made that still conform to the invention as described in this disclosure:

[0195] Figure 1 shows a higher molecular weight, primarily amphiphilic embodiment of the present invention with adjustable hydrophobicity and hydrophilicity. The value of m, which is the degree of substitution on the fullerene C70, can be between 2-70, but is most preferably between 8-40. The value of n, which is the length of the polyethylene glycol pendant polymer chain, can be between 1-800, but is most preferably between 86-96. The solubility and dispersibility of the invention in different media can be directly adjusted by changing the values of m and n, with higher m values giving greater hydrophilicity and therefore superior solubility and dispersibility in polar or aqueous media, and lower m values giving greater hydrophobicity and therefore superior solubility and dispersibility in non-polar or oily media. Higher n values give generally lower solubility and cause the invention to act more like a colloid or gel, whilst lower n values improve the solubility and can cause the invention to act more like a low -viscosity solute. When made with optimal m and n values, this embodiment of the present inventionexhibits excellent amphiphilicity and is particularly suitable for 50:50 oil-water emulsions, with strong emulsifying and moderate antimicrobial properties, but without the high charge-density ratio on the QAC group that can result in skin irritation or cytotoxicity to human cells. It is understood that the parameter m in the figure illustrates the number of substituents to the carbon nanoparticle in a general manner. It is self-evident that this should not indicate that m substituents are bound to one and the same carbon atom of the carbon nanoparticle.

[0196] Figure 2 shows a high molecular weight, primarily hydrophilic embodiment of the present invention. The value of m, which is the degree of substitution on the graphene, can be between 0.05-70%, but is most preferably between 20-50%. The value of n, which is the length of the quatemized amine polyurethane pendant polymer chain, can be between 1-800, but is most preferably between 30-120. The solubility and dispersibility of the invention in different media can be directly adjusted by changing the values of m and n, with higher m values giving greater hydrophilicity and therefore superior solubility and dispersibility in polar or aqueous media, and lower m values giving greater hydrophobicity and therefore superior solubility and dispersibility in non-polar or oily media. Higher n values give generally lower solubility due to increased molecular mass and cause the invention to act more like a colloid or gel, but give superior dispersibility in polar or aqueous media and enhanced antimicrobial efficacy due to the greater number of quaternary ammonium groups. When made with optimal m and n values, this embodiment of the present invention is particularly suitable for integration into thin polymer films due to its mechanical and chemical stability and high antimicrobial activity. It is understood that the parameter m in the figure illustrates the number of substituents to the carbon nanoparticle in a general manner. It is self-evident that this should not indicate that m substituents are bound to one and the same carbon atom of the carbon nanoparticle.

[0197] Figure 3 shows a lower molecular weight, adjustably amphiphilic embodiment of the present invention. The value of m, which is the degree of substitution on the fullerene Ceo, can be between 2-60, but is most preferably between 8-32. The solubility and dispersibility of the invention in different media can be directly adjusted by changing the value of m, with higher m values giving greater hydrophilicity and therefore superior solubility and dispersibility in polar or aqueous media, and lower m values giving greater hydrophobicity and therefore superior solubility and dispersibility in non-polar or oily media. When made with optimal m values, this embodiment of the present invention is particularly suitable for 50:50 oil: water emulsions, with strong emulsifying and antimicrobial properties, but without the high chargedensity ratio on the QAC group that can result in skin irritation. It is also relatively simple tosynthesise. It is understood that the parameter m in the figure illustrates the number of substituents to the carbon nanoparticle in a general manner. It is self-evident that this should not indicate that m substituents are bound to one and the same carbon atom of the carbon nanoparticle.

[0198] Figure 4 shows a higher molecular weight, carbon nanotube-based embodiment of the present invention. The value of m, which is the degree of functionalized carbon atoms in the carbon nanotube, can be between 1 out of 5 and 1 out of 10000 carbon atoms being functionalized, but is most preferably between 1:200-1:1000. The antimicrobial effectiveness of the invention can be directly adjusted by changing the value of m, with higher m values giving superior antimicrobial performance. When made with optimal m values, this embodiment of the present invention is particularly suitable for incorporation into both polymeric and inorganic materials due to its high mechanical strength and chemical resistance. It is understood that the parameter m in the figure illustrates the number of substituents to the carbon nanoparticle in a general manner. It is self-evident that this should not indicate that m substituents are bound to one and the same carbon atom of the carbon nanoparticle.

[0199] Figure 5 shows a Ceo fullerene with a propyltrimethylammonium as a substituent connected via an ether bond to the fullerene. It is understood that this illustrates only one substituent for the sake of clarity, wherein the number of said substituent on the inventive fullerene may be higher, such as for example 6 - 12 or 24 - 32.

[0200] Figure 6 shows the results dose-dependent toxicity of a Ceo fullerene with 6 - 12 propyltrimethylammonium as a substituent connected via an ether bond to the fullerene. Graphical representation of % viability according to data presented in "Table 4: Indirect assay - measurement of dose-dependent cytotoxicity". Data is shown as mean ± SD of 6-plicates. *p<0.05, ***p<0.005 compared to 0 mg / ml (non-treated L929 cells) (Kruskal -Wallis test). The dotted line represents a 30% reduction in cell viability, as a recommended limit for the interpretation of cytotoxicity in indirect assay according to ISO- 10993 -5.

[0201] Figure 7 shows representative measurements of cell viability by Muse Cell Analyser of Example 3. Nucleated cells are identified by acridine orange staining (live), whereas dead cells are additionally stained with propidium iodide (dead).

[0202] Figure 8 shows the dose-dependent toxicity of a Ceo fullerene with 24 - 32 propyltrimethylammonium as a substituent connected via an ether bond to the fullerene.Graphical representation of % metabolic activity according to data presented in Table 8. Data is shown as mean ± SD of 6-plicates with each replicate shown as a black dot. **p<0.01, compared to 0 mg / ml (non-treated L929 cells) (Kruskal-Wallis test). The dotted line represents a 30% reduction in cell viability, which was interpolated from dose-response curve at 7.3 mg / ml, as a recommended limit for the interpretation of cytotoxicity in indirect assay.

[0203] Examples

[0204] Example 1: General principles for the synthesis of the inventive carbon nanoparticle

[0205] As there are a plurality of embodiments of the present invention, there exists a plurality of synthetic methods and procedures to synthesize them. However, without applying a limitation or restriction on the various methods that can be used to prepare various embodiments of the present invention, the following general principles can be applied to the various syntheses of the various aspects and embodiments of the present disclosure:

[0206] It is generally preferred to quatemize the ammonium salt or quaternary ammonium group as a final step in the synthetic procedure. This is because ammonium salts or quaternary ammonium groups can be more sensitive to thermal decomposition or vulnerable to degradation or other interactions with other reaction media in other synthetic steps, especially catalysts when and where they are used.

[0207] It is generally preferred to use alkyl or aryl halides as quatemizing agents because of the high charge-density the halides generate as counterions, which generates a more stable and more effective product, and because of their ability to quatemize with minimal or zero generation of reaction by-products. This may especially be feasible for embodiments which otherwise may be difficult to purify by washing due to their amphiphilic nature.

[0208] It is generally preferred to functionalize the carbon nanoparticle with a linking organic group or the precursor to a linking organic group prior to attaching the ammonium salts or quaternary ammonium groups or the linker. The underlying reasoning is that the relative inertness and high stability of carbon nanoparticles, such as fullerenes, graphene and carbon nanotubes, mean that aggressive reaction conditions may be required to cause them to covalently bond, and these same aggressive reaction conditions may cause the degradation of the ammonium salts or quaternary ammonium groups or the linker. However, it is not always desirable to bond to all of the organic linking groups or their precursors, as these groups may themselves have desirable physiochemical properties - for example, unreacted carboxyl or thiol groups on the carbonnanoparticle may significantly enhance the solubility or dispersibility of the product in aqueous or polar media. However, it should be noted that enhanced solubility or dispersibility may also be achieved by means laid out above.

[0209] It is generally preferred, when determining the percentage of the embodiment comprising ammonium salts or quaternary ammonium groups, to strike a balance between the degree of substitution on the carbon nanoparticle (m in Figs. 1 and 2) and the degree of any polymeric chain that comprises ammonium salts or quaternary ammonium groups (n in Figs. 1 and 2). By balancing said parameters, cytotoxicity for human or animal cells may be minimalized by simultaneously increasing the surfactant capability.

[0210] The amphiphilic nature of some of the embodiments of the present invention may render them difficult to be purified by washing and separation in polar / non-polar media or chromatography. In these instances, it may be advantageous to design any synthetic process to ensure that the final step of the synthesis generates minimal, or ideally, no by-products. In the event that the generation of by-products is unavoidable, it is preferred that these by-products be removable by distillation or rotary evaporation.

[0211] Example 2: Cytotoxicity of a (To fullerene comprising 6 to 12 propyltrimethylammonium substituents bound via an ether bond

[0212]

[0213] The test was carried out according to the procedure for laboratory testing according to Standards ISO / DIS 10993-5: 2009. The method used for the study was direct and indirect contact between the fullerene and fibroblast cell culture. A Ceo fullerene comprising 6 to 12 propyltrimethylammonium substituents bound via an ether bond was used as the test sample.

[0214] For direct contact assay, the fullerene was dissolved in cell culture media and two different doses were placed carefully on a 30mm2filter paper (Whatman, qualitative filter paper, Merk) (20pl of 60 mg / ml solution) and then the filter paper was placed on the adherent monolayer of L929 cells. Two doses were used for the direct assay measurements:

[0215] 1. 600 pg / 30mm2 / 2ml

[0216] 2. 150 pg / 30mm2 / 2ml

[0217] In the indirect assay format, 10 different doses were prepared in complete RPMI medium, including 3 mg / ml, 2 mg / ml, 1 mg / ml, 0.5 mg / ml, 0.25 mg / ml, 0.125 mg / ml, 0.0625 mg / ml,0.03125 mg / ml, 0.015625 mg / ml and 0.007813 mg / ml. The solutions were placed on semiadherent layers (70% confluency) of L929 cells in 6-plicates.

[0218] As a negative control for direct assay, 30mm2 filter paper (Whatman) alone was used. In the indirect assay, only complete cell culture medium was used.

[0219] As a positive control in a direct assay, a preparation confirmed to induce cytotoxic changes was used, and it consisted of 10 pl of 10% Triton X (final concentration 0.05%) on 30mm2filter paper (Whatman). For the indirect assay, a total concentration of 0.05% Triton-X was used in the cell cultures.

[0220] As a blank control fibroblast cell culture without the test material was used in the direct assay.

[0221] The medium used was complete medium for cultures: RPMI 1640 (Sigma) supplemented with 10% fetal calf serum (ICN), 2mM glutamine (Sigma), 100 lU / ml penicillin (Galenika) and 0,5% streptomycin (Galenika).

[0222] The cells used were CTC, clone L929, of mice adipose tissue origin, having a fibroblast morphology and obtained from Hammersmith Hospital, London, UK, Department of Immunology.

[0223] Incubation was performed at 37°C under 5% CO2 in a Heraeus incubator. The procedure was carried out under a sterile vertical laminar.

[0224] In direct assay format, the test sample, and positive and negative controls were done in triplicates. For indirect contact assay, all doses of the test substance, positive and negative controls were carried out in 6-plicates.

[0225] For the direct assay format, L929 cells were cultivated in 6-well plates until they reached 80-90% of confluence. Before the treatments, the medium was changed and the test sample, positive and negative controls were placed on the cells so that they were in direct contact with the cell layer. It is expected that the test substance diffuses from the filter paper into the local solution, mostly affecting the cells in direct contact.

[0226] In the indirect assay format, L929 cells were cultivated in 96-well plates until they reached 70% of confluence. After changing the medium, the cells were treated with different doses of test substance followed by the assessment of cell viability and cell number. In this assay format all present cells are equally exposed to the test substance.The entire procedure of performing cytotoxicity tests was based on the principles of Good Laboratory Practice (Coecke et al., Guidance on Good Cell Culture Practice, A Report of the Second ECVAM Task Force on Good Cell Culture Practice, ATLA 33, pp 261- 287, 2005). These principles include regular testing of the cultures for the presence of contamination with mycoplasma (Mycoalert colorimetric test), as well as for the absence of changes in cell morphology and chromosomal aberrations or deviations in the normal cell division cycle. L929 cells were stored in liquid nitrogen. Two weeks before the experiment the cells were defrosted and rinsed from dimethyl-sulfoxide (DMSO), and they were then cultivated in T25 or T75 flasks at a temperature of 37°C and 5% CO2 for at least 2 passages. Usually, L929 cells grow in the form of an adherent layer. At first, they have an elongated, spindle-shaped appearance, and when they become confluent, the typical cobblestone appearance is observed. The confluent cells are then re-passaged by trypsinization or plated in a series of cell culture plates at least one day before the test.

[0227] Samples for testing, i.e., different doses of the fullerene sample on the Whatman filter paper, and corresponding positive and negative controls were placed on the center of the wells of 6-well plates on a layer of adherent L929 cells using sterile tweezers. The plates were numbered and then incubated for 24h at 37°C with 5% CO2. Each well of the plate was examined under an inverted light microscope after 24h. After a qualitative assessment (a) and photographing of the samples, a quantitative assay (b) was performed for the cytotoxicity assessment. The samples were carefully removed and then the medium, containing non-adherent cells, was collected from the plates using Pasteur pipettes.

[0228] The cells were rinsed in phosphate buffer (PBS). The non-adherent cells collected in PBS were merged with the cells previously collected in the medium. L929 cells were then treated with 2 ml 0.1% trypsin solution (Serva, catalogue no. 37260.02) for 5 minutes at 37°C in an incubator. During this time, all adherent cells became non-adherent under the action of trypsin. The trypsinization was stopped by adding 0.5 ml FCS to the trypsin solution. Non-adherent cells were collected using a Pasteur pipette and the plates were then rinsed once more with PBS. All cells collected from the plates during the process were pooled and centrifuged at 1600 rpm for 10 minutes. Supernatants were discarded, and cell pellets were assessed for cell viability.

[0229] The procedure for indirect assay format was performed likewise, in 96-well plates. The samples were treated upon reaching 70% confluence to allow the test substance to potentially alter the cell growth besides the direct cytotoxic effect. Considering that the fullerene sample wascolored, and absorbed light at 540 nm, it was not possible to measure cell viability by MTT assay, as recommended by ISO 10933-5 (data not shown). Instead, the dose-dependent effect of the fullerene sample on viability and total number of viable cells was measured within the indirect assay format using the alternative method according to the ISO 10933-5 guidelines. The principle of measuring cell viability and the number was as follows: cellular pellet after trypsinization was resuspended in 500 pl of complete RPMI medium and then 20 pl of the cell suspension was mixed with the 180 pl of Cell Count and Viability kit (Muse Cell Analyser, Cytek) which contain a mixture of Acridine orange, for labelling nucleated cells, and propidium iodide for labelling dead cells. The cells were then counted on Muse Cell Analyser (Cytec, IVD device), and at least 1000 cells were counted per sample / replicate. The percentage of dead / viable cells and the total number of cells were then directly calculated by using a Muse Cell Analyser.

[0230] The cytotoxic effect was estimated by taking notes about the malformations, degenerations, detachments from the surface, fragmentations and lysis of cells around the sample prepared on Whatman filter paper.

[0231] Table 1: Qualitative morphological gradation of cytotoxicity

[0232]

[0233] In a quantitative assay the cytotoxic effect is estimated based on the percentage of lysed cells (estimation of cytotoxicity); Standard ISO 10993-5:2009(E).Index: 0 - Undetectable cytotoxicity or basal cytotoxicity which is detected in the control; 1 -Less than 30% of lysed (non-viable) cells; 2 - 30-45% of lysed (non-viable) cells. 3 - 45-60% of lysed (non-viable) cells; 4 - 60-85% of lysed (non-viable) cells; 5 - More than 85% of lysed (non-viable) cells.

[0234] Interpretation: Index 0 - no cytotoxic effect; Index 1 - discrete cytotoxicity; Index 2 - mild cytotoxicity; Index 3 - moderate cytotoxicity; Indexes 4 and 5 - serious cytotoxicity.

[0235] Results:

[0236] Table 2: Direct assay - quantitative assessment

[0237]

[0238] Table 3 : Direct assay - qualitative assessment

[0239]

[0240] Table 4: Indirect assay - measurement of % viability

[0241]

[0242] Conclusion:

[0243] The qualitative and quantitative cytotoxicity tests on L929 cells showed that: the investigated fullerene does not cause cytotoxic effects in concentrations up to 1 mg / ml, whereas in higher concentrations it induces cell toxicity. IC50 value for the fullerene, according to these investigations was 2.37 mg / ml. Although not cytotoxic, doses close to 1 mg / ml may slightly reduce the cell growth, probably as the particles are internalized by the cells in vitro.

[0244] Example 3: Antimicrobial capacity of a Ceo fullerene comprising 24 to 32 propyltrimethylammonium substituents bound via an ether bond

[0245] The test was carried out according to the procedure for laboratory testing according to Standards ISO / DIS 10993-5: 2009. The method used for the study was direct and indirect contact between the fullerene and fibroblast cell culture. A Ceo fullerene comprising 24 to 32 propyltrimethylammonium substituents bound via an ether bond was used as the test sample.

[0246] For direct contact assay, the fullerene was dissolved in cell culture media and two different doses were placed carefully on a 30mm2filter paper (Whatman, qualitative filter paper, Merk) (40pl and 20pl of 60 mg / ml solution) and then the filter paper was placed on the adherent monolayer of L929 cells. Two doses were used for the direct assay measurements:

[0247] 1. 1500 pg / 30mm2 / 2ml

[0248] 2. 750 pg / 30mm2 / 2ml

[0249] In the indirect assay format, 7 different doses were prepared in complete RPMI medium, including 8000 pg / ml, 4000 pg / ml, 2000 pg / ml, 1000 pg / ml, 500 pg / ml, 250 pg / ml, 125 pg / ml.The solutions were placed on semi-adherent layers (70% confluency) of L929 cells in 6-plicates.

[0250] As a negative control for direct assay, 30mm2filter paper (Whatman) alone was used. In the indirect assay, only complete cell culture medium was used.

[0251] As a positive control in a direct assay, a preparation confirmed to induce cytotoxic changes was used, and it consisted of 10 pl of 10% Triton X (final concentration 0.05%) on 30mm2filter paper (Whatman). For the indirect assay, a total concentration of 0.05% Triton-X was used in the cell cultures.

[0252] As a blank control fibroblast cell culture without the test material was used in the direct assay.

[0253] The medium used was complete medium for cultures: RPMI 1640 (Sigma) supplemented with 10% fetal calf serum (ICN), 2mM glutamine (Sigma), 100 lU / ml penicillin (Galenika) and 0,5% streptomycin (Galenika).

[0254] The cells used were CTC, clone L929, of mice adipose tissue origin, having a fibroblast morphology and obtained from Hammersmith Hospital, London, UK, Department of Immunology.

[0255] Incubation was performed at 37°C under 5% CO2 in a Heraeus incubator. The procedure was carried out under a sterile vertical laminar.

[0256] In direct assay format, the test sample, and positive and negative controls were done in triplicates. For indirect contact assay, all doses of the test substance, positive and negative controls were carried out in 6-plicates.

[0257] For the direct assay format, L929 cells were cultivated in 6-well plates until they reached 70% of confluence. Before the treatments, the medium was changed and the test sample, positive and negative controls were placed on the cells so that they were in direct contact with the cell layer. It is expected that the test substance diffuses from the filter paper into the local solution, mostly affecting the cells in direct contact.

[0258] In the indirect assay format, L929 cells were cultivated in 96-well plates until they reached 70% of confluence. After changing the medium, the cells were treated with different doses of the test substance followed by the assessment of their total metabolic activity, as a measure of viability,proliferation and cell growth. In this assay format all present cells are equally exposed to the test substance

[0259] The entire procedure of performing cytotoxicity tests was based on the principles of Good Laboratory Practice (Coecke et al., Guidance on Good Cell Culture Practice, A Report of the Second ECVAM Task Force on Good Cell Culture Practice, ATLA 33, pp 261- 287, 2005). These principles include regular testing of the cultures for the presence of contamination with mycoplasma (Mycoalert colourimetric test), as well as for the absence of changes in cell morphology and chromosomal aberrations or deviations in the normal cell division cycle. L929 cells were stored in liquid nitrogen. Two weeks before the experiment the cells were defrosted and rinsed from dimethyl-sulfoxide (DMSO), and they were then cultivated in T25 flasks at a temperature of 37°C and 5% CO2 for at least 2 passages. Usually, L929 cells grow in the form of an adherent layer. At first, they have an elongated, spindle-shaped appearance, and when they become confluent, the typical cobblestone appearance is observed, and the proliferating cells appear as rounded, slightly attached cells with visible chromatin. The confluent cells are then re-passaged by trypsinization or plated in a series of cell culture plates at least one day before the test.

[0260] Direct cytotoxicity assay: Samples for testing, i.e., different doses of the fullerene samples on the Whatman filter paper, and corresponding positive and negative controls were placed on the center of the wells of 6-well plates on a layer of adherent L929 cells using sterile tweezers. The plates were numbered and then incubated for 24h at 37°C with 5% CO2.

[0261] Each well of the plate was examined under an inverted light microscope after 24h. After a qualitative assessment (a) and photographing of the samples, a quantitative assay (b) was performed for the cytotoxicity assessment. The samples were carefully removed and then the medium, containing non-adherent cells, was collected from the plates using Pasteur pipettes. The cells were rinsed in phosphate buffer (PBS). The non- adherent cells collected in PBS were merged with the cells previously collected in the medium. L929 cells were then treated with 2 ml 0.1% trypsin solution (Serva, catalogue no. 37260.02) for 5 minutes at 37°C in an incubator. During this time, all adherent cells became non-adherent under the action of trypsin. The trypsinization was stopped by adding 0.5 ml FCS to the trypsin solution. Non-adherent cells were collected using a Pasteur pipette and the plates were then rinsed once more with PBS. All cells collected from the plates during the process were pooled and centrifuged at 1600 rpm for10 minutes. Supernatants were discarded, and cell pellets were assessed for cell viability by using Cell Muse, count and viability assay kit (Cytek).

[0262] Indirect cytotoxicity assay: The procedure for indirect assay format was performed likewise, in 96-well plates. The samples were treated upon reaching 70% confluence to allow the test substance to potentially alter the cell growth besides the direct cytotoxic effect. The viability and proliferation of the cells were measured via MTT assay, which indicates total metabolic activity in the culture. Since the fullerene samples in the used doses (0.125 mg / ml - 8 mg / ml) did not interfere with the MTT absorption at 540 nm, the test was performed as recommended by ISO 10933-5.

[0263] MTT test was carried out according to Anex C ISO 10933-5:2009. In principle, yellow hydrophilic MTT (3- 4,5-dimethylthiazol-2-yl -2,5-difenltetrazoliumbromid) is being reduced by cellular succinate dehydrogenase into insoluble formazan. The number of live, metabolically active, cells directly correlate with this conversion which can be measured by spectrophotometry upon dissolving formazan with HC1 in SDS. Therefore, L929 cells were cultivated in the presence of 7 doses of the fullerene samples (8000 pg / ml, 4000 pg / ml, 2000 pg / ml, 1000 pg / ml, 500 pg / ml, 250 pg / ml, 125 pg / ml), negative control (0 pg / ml) and positive control (0.05% Triton-X) for 24h. Cell-free controls were carried out for the same doses of the test substance. After that, MTT solution (0.5 mg / ml) in complete RPMI, was added to each well. After 5h of incubation of cells with MTT at 37 °C and 5% CO2, the cultures were treated with 100 pl of 0.0 IN HC1 in 10% SDS in ddkhO to dissolve formazan. This solution also enables degradation of the cell membrane, allowing direct measurement of absorbance in the 96-wells plate.

[0264] Absorbance was read on microplate reader (DC 990 BV4, NT, Rome) at 570nm (OD570) and referenced wavelength at 670nm (OD670), for optical correction. The test criteria included that the reading at OD570 in the control non-treated cultures is higher than 0.2 units, and that control cells placed on two different sides of a microtiter plate do not differ by more than 15%.

[0265] The cytotoxic effect was estimated by taking notes about the malformations, degenerations, detachments from the surface, fragmentations and lysis of cells around the sample prepared on Whatman filter paper.

[0266] Table 5: Qualitative morphological gradation of cytotoxicity

[0267]

[0268] In a quantitative assay the cytotoxic effect is estimated based on the percentage of lysed cells (estimation of cytotoxicity); Standard ISO 10993-5:2009(E).

[0269] Index: 0- Undetectable cytotoxicity or basal cytotoxicity which is detected in the control; 1-Less than 30% of lysed (non-viable) cells; 2- 30-45% of lysed (non-viable) cells. 3- 45-60% of lysed (non-viable) cells; 4- 60-85% of lysed (non-viable) cells; 5- More than 85% of lysed (non-viable) cells.

[0270] Interpretation: Index 0- no cytotoxic effect; Index 1- discrete cytotoxicity; Index 2 - mild cytotoxicity; Index 3 - moderate cytotoxicity; Indexes 4 and 5 - serious cytotoxicity.

[0271] In the indirect cytotoxicity assay (MTT) the reduction of cell viability can be observed as the reduction of metabolic activity of the cells treated with the sample. This reduction correlates with the amount of formazan formed in the culture and the % metabolic activity (i.e. viability) is calculated as:

[0272]

[0273] Results:

[0274] Table 6: Direct assay - qualitative assessment

[0275]

[0276] Table 7: Direct assay - quantitative assessment

[0277]

[0278] The quantitative assessment of the fullerene at the two indicated doses did not show any signs of cytotoxicity at the applied doses. The viability in this assay was measured by a Cell Muse Analyser, which measures simultaneously the morphology of the cells and viability based on PI staining (s. Fig. 7). Although the viability of the cells was not affected significantly, the morphology was slightly altered, i.e., an increased signal in the side-scatter parameter (indicated as nucleated cells on the Y-axis) was noticed. This could be interpreted as increased internal complexity of the cells, possibly due to internalized material.

[0279] Table 8: Indirect assay - measurement of % viability

[0280]

[0281] Conclusion:

[0282] The qualitative and quantitative cytotoxicity tests on L929 cells showed that: the investigated fullerene sample does not cause cytotoxic effects in concentrations up to 7.3 mg / ml, whichcalculated based on dose-response curve from viability assessment and considering that 70% viability (i.e. 30% reduction of viable cells) is a borderline for proclamation of cytotoxicity according to ISO 10993-5. IC50 value (a dose expected to reduce viability to 50%) was calculated from the dose-response curve to be 11.47 mg / ml.

[0283] The particles could not be observed directly by light microscopy. The cells treated with 1.5 mg / ml and 0.75. mg / ml showed slightly increased side / scatter properties, suggesting that they might have internalized the particles from the sample.

[0284] Example 4: Preparation of a higher molecular weight, amphiphilic embodiment of the invention with adjustable hydrophobicity / hydrophilicity particularly suitable for 50:50 oil: water emulsions

[0285] Pristine fullerene C70 as a raw material was purchased from MST Nano corporation.

[0286] Polycyclosulphonated fullerene precursor was prepared by reacting the fullerene C70 with 70% sulphuric acid with high agitation using a homogenizer under an inert atmosphere at 60°C. The reaction time of this stage varies from 2-72 hours, with the reaction time directly correlating with the degree of sulphonation of the fullerene C70, in turn directly correlating with the degree of substitution on the finished product (with reference to FIG. 1, the value of m increases with increased reaction time). A longer reaction time and higher degree of substitution results in a more hydrophilic product, whilst a lower reaction time and lower degree of substitution results in a more hydrophobic product.

[0287] The product of the reaction is added dropwise to diethyl ether, whereupon the precipitate is collected, washed further with diethyl ether and dried under vacuum at 50°C. This is the polycyclosulphonated fullerene precursor.

[0288] The polycyclosulphonated fullerene precursor is mixed into an excess of polyethylene glycol (with reference to FIG. 1, the value of n is determined by the choice of polyethylene glycol -polyethylene glycol 4000 is particularly preferable, with n = 91±5). This is mixed at high agitation at 80°C under an inert atmosphere for 6-48 hours, with required mixing time dependent upon the degree of sulphonation in the previous reaction step. A significant excess of polyethylene glycol is required to prevent cross-linking of the different fullerenes to one another, with the ratio of polycyclosulphonated fullerene: polyethylene glycol determined by the degree of sulphonation and the molecular mass of the polyethylene glycol.The product, C70 functionalized with polyethylene glycol pendant polymer chains, is washed with pure water to remove the polyethylene glycol and sulphuric acid byproduct and isolated by passing through a silica gel column.

[0289] The product is mixed with N,N-dimethylglycine (amount dependent upon the degree of sulphonation in the first step of the reaction) and a small amount of sulphuric acid (reaction solvent dependent upon the degree of sulphonation as this affects product solubility) and mixed at high agitation at 80°C for 24-48 hours under a strong vacuum, fitted with condenser to collect the water by-product and drive the reaction to completion. The product is washed with water to remove the excess N,N-dimethylglycine.

[0290] The final step, quaternization of the aminated product, is performed by mixing the product with an excess of 1 -bromobutane in methanol solvent at high agitation under reflux at 100°C for 48 hours. The finished product (illustrated in FIG. 1 with only one substituent) which will be either a precipitate or solution dependent upon the degree of substitution (determined by the degree of sulphonation in the first step of the reaction), can be purified either by centrifugation and washing with diethyl ether or via distillation under high vacuum and washing with diethyl ether.

[0291] Example 5: Preparation of a higher molecular weight, hydrophilic embodiment of the invention particularly suitable for integration into polymer films

[0292] Single-layer graphene powder in aqueous suspension, of flake diameter 400-5000nm and thickness 0.6-1.2nm, was purchased from ACS Materials.

[0293] Hydroxylated graphene precursor was prepared by dispersing the graphene powder in 30-50% aqueous hydrogen peroxide and treating with a Bandelin Sonopuls fitted with a TT-213 horn at 100W. The reaction time of this stage varies from 30-180 minutes, with the reaction time and hydrogen peroxide concentration directly correlating with the degree of hydroxylation of the graphene sheets, which in turn directly correlates with the degree of substitution on the finished product (with reference to FIG. 2, the value of m increases with increased reaction time and hydrogen peroxide concentration). The excess hydrogen peroxide is washed off with water and the product dried at 90°C.

[0294] An isocyanate-terminated tertiary amine polymer is prepared by mixing methyldiethanolamine with a slight excess of methyl diphenyl diisocyanate in dichloromethane solvent, with a small quantity of l,8-diazabicyclo(5,4,0)undec-7-ene catalyst at high agitation under an inert atmosphere at 20°C for 6-48 hours. With reference to FIG. 2, the value of n is determined by the reaction time and the concentration of catalyst, with a preferable value of n = 30-120). Thepolymer will precipitate as a gel and can be removed by mechanical means, then washed with octane to remove the excess methyl diphenyl diisocyanate and catalyst.

[0295] The hydroxylated graphene is mixed with the isocyanate-terminated tertiary amine polymer in tetrahydrofuran solvent, with a small quantity of l,8-diazabicyclo(5,4,0)undec-7-ene catalyst at high agitation under an inert atmosphere at 20°C for 24-48 hours (reaction time determined by degree of hydroxylation carried out during the first step of the reaction). The product will again precipitate as a gel of much higher density and of a darker color than the isocyanate-terminated tertiary amine polymer, which can be removed by mechanical means and washed with tetrahydrofuran to remove the excess polymer and catalyst.

[0296] To cap the isocyanate-terminated ends of the pendant polymer chains, the product is mixed with an excess of 2-dimethylaminoethanol in tetrahydrofuran solvent, with a small quantity of 1,8-diazabicyclo(5,4,0)undec-7-ene catalyst at high agitation under an inert atmosphere at 20°C for 12 hours. The product, a gel, can be removed by mechanical means and washed with tetrahydrofuran to remove the excess 2-dimethylaminoethanol and catalyst. Note that this step of the synthesis is optional, as leaving the pendant polymer chains with isocyanate terminal groups allows the material to act as a cross-linker in a polyurethane and that way become part of the polymer rather than a composite.

[0297] The final step, quaternization of the aminated product, is performed by mixing the product with an excess of iodomethane in methanol solvent at high agitation under reflux at 50°C for 72 hours. The finished product (illustrated in FIG. 2 with only one substituent) is purified by rotary evaporation or distillation to remove the methanol and excess iodomethane.

[0298] Example 6: Preparation of a lower molecular weight, amphiphilic embodiment of the present invention particularly suitable for cosmetic formulations

[0299] Pristine fullerene Ceo as a raw material was purchased from MST Nano corporation.

[0300] Hydroxylated fullerene precursor was prepared by dissolving the fullerene Ceo in toluene, which was mixed with 2-50% sodium hydroxide aqueous solution with high agitation using a homogenizer. The reaction time of this stage varies from 0.5-48 hours, with the reaction time and sodium hydroxide concentration directly correlating with the degree of hydroxylation of the fullerene, in turn directly correlating with the degree of substitution on the finished product (with reference to FIG. 3, the value of m increases with increased reaction time and sodium hydroxide concentration). The excess sodium hydroxide is washed off with water and theproduct washed 2-6 times with toluene to remove unreacted fullerene. The product is dried in an oven.

[0301] The aminated fullerene is prepared by mixing the product with 3-chloro-N,N-dimethylpropan-1 -amine in water solvent, with a small amount of sodium hydroxide, and stirred under reflux at 150°C for 12-72 hours. The product is dried rapidly under rotary evaporation to remove hydrogen chloride byproduct, and then washed with acetone to remove the product, leaving the sodium hydroxide behind. The acetone is removed via rotary evaporation or drying in an oven. The final step, quaternization of the aminated product, is performed by mixing the product with an excess of benzyl bromide in methanol solvent at high agitation under reflux at 100°C for 72 hours. The finished product, shown in FIG. 3, is purified by rotary evaporation at high vacuum or distillation to remove the methanol and excess benzyl bromide.

[0302] Example 7: Preparation of a high molecular weight, high mechanical strength embodiment of the present invention suitable for integration into both polymers and inorganic media

[0303] Single-walled carbon nanotubes functionalized with primary amines were purchased from Nano-Lab. With reference to FIG. 4, the value of m is determined by the degree of amination on the carbon nanotube, which can be adjusted either by acquiring the carbon nanotubes from a different supplier or by synthesizing them under different conditions in accordance with (Ruelle B, Peeterbroeck S, Godfroid T, Bittencourt C, Hecq M, Snyders R, Dubois P. Selective Grafting of Primary Amines onto Carbon Nanotubes via Free-Radical Treatment in Microwave Plasma Post-Discharge. Polymers. 2012; 4(1 ):296-315. https: / / doi.org / 10.3390 / polym4010296 or Koji Yokoyama, Yoshinori Sato, Masashi Yamamoto, TetsuoNishida, Takashi Itoh, Kenichi Motomiya, Yoshinori Sato, Functionalization of primary amine groups to single-walled carbon nanotubes by reacting fluorinated SWCNTs with ammonia gas at a low temperature, Carbon, Volume 172, 2021, Pages 360-371, ISSN 0008-6223, https: / / doi.Org / 10.1016 / j.carbon.2020.10.038.).

[0304] The amine-functionalized carbon nanotubes are mixed with 4-pyridinecarboxylic acid in dimethylformamide solvent at high agitation at 140°C for 48 hours under a light vacuum, fitted with condenser to collect the water by-product and drive the reaction to completion. The tertiary amine-functionalized carbon nanotubes are separated from suspension via centrifugation and washed with acetone to remove unreacted 4-pyridinecarboxylic acid and dimethylformamide.For quaternization, after drying, the tertiary amine-functionalized carbon nanotubes are crushed into a fine powder and sealed in a pressure reactor fitted with powder agitator. All air is removed from the system, and the material is then agitated under a bromomethane atmosphere at 200-400 kPa pressure for 48-96 hours.

Claims

Claims1. A carbon nanoparticle derivatized with at least one substituent covalently bonded to a carbon atom of said carbon nanoparticle, wherein the substituent comprises at least one ammonium and / or cationic quaternary ammonium group with an appropriate anion.

2. The carbon nanoparticle of claim 1, characterized in that the substituent is a linear, branched or cyclic organic group containing one or more ammonium groups, cationic quaternary ammonium groups or a quaternary ammonium salt polymer, each with their appropriate anions, or a mixture of said cationic species.

3. The carbon nanoparticle of claim 1 or 2, characterized in that the carbon nanoparticle is derivatized with substituents in a ratio of from 0.01 to 1.7 substituents per carbon atom of the carbon nanoparticle, preferably of from 0.02 to 0.8 substituents per carbon atom of the carbon nanoparticle, more preferably of from 0.05 to 0.5 substituents per carbon atom of the carbon nanoparticle, and even more preferably of from 0.1 to 0.25 substituents per carbon atom of the carbon nanoparticle.

4. The carbon nanoparticle of claims 1 to 3, characterized in that the carbon nanoparticle is selected from the group consisting of a carbon nanotube (CNT), a fullerene, graphene, graphene oxide, a nanodiamond, and preferably is a fullerene.

5. The carbon nanoparticle of claim 4, characterized in that the fullerene is represented by the formula Cn with n = 60 to 100, wherein the fullerene is preferably, a Ceo, C70, C72, C74, Cso, Cs2, or Cs4 fullerene.

6. The carbon nanoparticle of claim 4 or 5, characterized in that the fullerene is an endohedral fullerene preferably selected from the group consisting of endohedral metallofullerene (EMF) such as mono-EMFs, di-EMFs, and cluster-EMFs; non-metal doped fullerene such as He@Ceo, Ne@Ceo, N@Ceo, N@C?o and P@Ceo; and molecular endofullerenes containing small molecules such as H2@Ceo, H20@Ceo, and CH4@Ceo.

7. The carbon nanoparticle of claim 4, characterized in that the carbon nanotube is a single-walled carbon nanotube (SWCNTs) or a multi-walled carbon nanotube(MWCNTs).

8. The carbon nanoparticle of claim 7, characterized in that the carbon nanotube is an encapsulated CNT; a doped CNT such as nitrogen-, boron-, or phosphorus-doped CNT; an armchair CNT; a zigzag CNT or a chiral CNT.

9. The carbon nanoparticle of claim 7 or 8, characterized in that the carbon nanotube has a length from 5 nm to 500 nm, preferably a length of 10 to 250 nm and more preferably a length from 50 to 150 nm.

10. The carbon nanoparticle of claim 4, characterized in that the graphene is a monolayer graphene or a multilayer graphene.

11. The carbon nanoparticle of claim 10, characterized in that the graphene is selected from the list consisting of exfoliated graphene, chemical vapor deposition graphene, graphene synthesized by chemical reduction of graphene oxide, liquid-phase exfoliated graphene and epitaxially grown graphene.

12. The carbon nanoparticle according to any of the preceding claims, characterized in that the cationic quaternary ammonium group has the formula RIR2R3R4N+X', wherein Ri, R2, R3 and R4 represent, independently a substituted or unsubstituted and / or straight chain or branched and / or interrupted or uninterrupted alkyl, aryl, alkylaryl, arylalkyl, cycloalkyl, heterocyclyl or alkenyl group or two or more Ri, R2, R3 and R4 together with the nitrogen atom form a substituted or unsubstituted heterocyclic ring, and wherein the total number of carbon atoms in the groups Ri, R2, R3 and R4 is at least 4;wherein the substituents for the groups Ri, R2, R3 and R4 are selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, heterocyclyl, substituted heterocyclyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl, F, Cl, Br, I, -OR', - NR’R” -CF3, -CN, -NO2 ,-C2R’, -SR’, -N3, -C(=O)NR’R”, -NR”C(=O)R", -C(=O)R’, -C(=O)OR’, -OC(=O)R’, -O(CR’R”)rC(=O)R’, -O(CR’R”)rNR”C(=O)R’, - O(CR’R”)rNR”SO2R’, -OC(=O)NR’R”, -NR’C(O)OR”, -SO2R’, -SO2NR’R”, and - NR’SO2R”;wherein R’ and R” are individually hydrogen, C1-C12 alkyl, cycloalkyl, heterocyclyl, aryl, or arylalkyl, and r is an integer from 1 to 6, or R’ and R” together form a cyclic functionality;wherein the term "substituted" as applied to alkyl, alkenyl, heterocyclyl, cycloalkyl, aryl, alkylaryl and arylalkyl refers to the substituents described above, starting with F and ending with -NR’SChR”;wherein X- is a halide anion, a hydrogen sulphate anion, a sulphate anion, hydroxide anion, bicarbonate anion, carbonate anion, a carboxylate anion containing up to 18 carbon atoms, lactate anion, tartrate anion, gluconate anion, saccharinate anion, an alkanesulfonate anion, an arenesulphonate anion, phosphate ion, hydrogen phosphate ion, or dihydrogen phosphate ion, or a mixture of two or more of these ions;and wherein for attachment to the carbon nanoparticle one of the following is given:(a) one of Ri, R2, R3 and R4 is the carbon nanoparticle, and preferably a fullerene, or (b) one or two of Ri, R2, R3 and R4 further contain a - preferably terminally located - functional group for covalent bonding of the respective R1-4 to the carbon nanoparticle by (i) establishing a direct covalent bonding of the respective R1-4 to the carbon atom of the carbon nanoparticle, or by (ii) establishing a covalent bonding to a linker for indirect coupling to the carbon atom of the carbon nanoparticle.

13. The carbon nanoparticle according to claim 12, characterized in that the cationic quaternary ammonium group has the formula (CH3)n(A)mN+X‘, wherein each A is independently as defined for Ri, R2, R3 and R4, n is from 1 to 3 and m is from 1 to 3 provided that the sum of n and m is 4.

14. The carbon nanoparticle according to claim 13, characterized in that each A is independently a C3-20 substituted or unsubstituted and / or straight chain or branched and / or interrupted or uninterrupted alkyl, aryl, alkylaryl, arylalkyl or cycloalkyl group.

15. The carbon nanoparticle according to claim 14, characterized in that the cationic quaternary ammonium group is selected from propyltrimethylammonium bromide, Cetrimide, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide.

16. The carbon nanoparticle according to claim 15, characterized in that the carbon nanoparticle is a fullerene, preferably a Ceo fullerene, the cationic quaternary ammonium group is propyltrimethylammonium bromide, and the number of cationic quaternary ammonium groups per fullerene is from n = 6 - 12 or from n = 12 - 24.

17. The carbon nanoparticle according to claim 13, characterized in that n = 2 and m = 2 and each A is the same or different and is a straight chain, unsubstituted and uninterrupted Cs-12 alkyl group or a benzyl group.

18. The carbon nanoparticle according to claim 12 or 13, characterized in that the cationic quaternary ammonium group is a benzalkonium halide or an aryl ring substituted derivative thereof.

19. The carbon nanoparticle according to claim 18, characterized in that the benzalkonium halide has the formula:wherein R is as defined for Ri, R2, R3 and R4.

20. The carbon nanoparticle according to claim 19, characterized in that R is a Cs-18 alkyl group or a mixture of Cs-i8 alkyl groups.

21. The carbon nanoparticle according to claim 20, characterized in that R is a mixture of straight chain, unsubstituted and uninterrupted Cs-18 alkyl groups.

22. The carbon nanoparticle according to any of claims 12 to 21, characterized in that one or more of Ri, R2, R3 and R4 is an alkyl, aryl, alkylaryl, arylalkyl or cycloalkyl group interrupted by a heteroatom selected from oxygen, nitrogen, sulphur, and a phosphorus- containing moiety.

23. The carbon nanoparticle according to claim 12, characterized in that the cationic quaternary ammonium group is selected from the group consisting of domiphen bromide, benzethonium chloride, benzyldimethyl-n-tetradecyl-ammonium chloride, benzyldimethyl-n-dodecyl-ammonium chloride, n-dodecyl-n-tetradecyldimethyl- ammonium chloride and benzyl-Ci2-Ci6-alkyl-dimethyl-ammonium chloride, benzyl- cocoalkyl-dimethyl-ammonium chloride, di-n-decyldimethyl-ammonium chloride, bridged cyclic amino compounds such as the hexaminium compounds, cetalkonium chloride, cetylpyridinium chloride, glycidyl trimethyl ammonium chloride, stearalkonium chloride, zephiran chloride, diisobutylphenoxy ethoxy ethyl-dimethylbenzylammonium chloride, N-Benzyl-N,N-dimethyl-N-[4-(l.1.3.3- tetramethylbutyl)-phenoxyethoxyethyl]ammonium chloride, cetalkonium chloride, cetyl dimethylbenzylammonium chloride, cetyltrimethylammonium bromide, 1- hexadecylpyridinium chloride, glycidyltrimethylammonium chloride, benzethonium chloride CAS 121-54-0, cetalkonium Chloride CAS 122-18-9, cetrimide CAS 8044-71- 1, stearalkonium chloride CAS 122-19-0, cetrimonium bromide CAS 57-09-0, benzalkonium chloride, phenyltrimethylammonium chloride, phenyltrimethylammoniuim iodide, benzyldimethyl-hexadecylammonium chloride, phenylbenzylammonium chloride, 4, 4‘-bipyridinium-l,r -dimethyl di chloride (paraquat), dibromide, diiodide, 2,2‘-bipyridinium-l,r-dimethyl dichloride, dibromide and diiodide, 4,4‘-bipyridinium-l,r-dibenzyl dichloride, dibromide and diiodide, and mixtures thereof.

24. The carbon nanoparticle according to any of claims 12 to 23, characterized in that the carbon nanoparticle is derivatized with a combination of at least two different cationic quaternary ammonium groups.

25. The carbon nanoparticle according to any of claims 12 to 24, characterized in that the linker comprises straight-chain saturated or unsaturated hydrocarbons from 1-30 atoms, branched-chain saturated or unsaturated hydrocarbons from 1-30 atoms, cyclic or polycyclic aliphatic hydrocarbons from 5-30 atoms, homocyclic or heterocyclic aromatic hydrocarbons comprising from 5-10 atoms in their ring(s).

26. The carbon nanoparticle according to claim 25, characterized in that one or a plurality of the hydrocarbons of the linker contains one or more substituents comprising noncarbon atoms, including nitrogen, oxygen, sulphur, silicon, fluorine, chlorine, bromine and iodine.

27. The carbon nanoparticle according to any of claims 12 to 24, characterized in that the linker is a polymeric linker.

28. The carbon nanoparticle according to claim 27, characterized in that the polymeric linker is a linear polymeric linker which is preferably selected from the group consisting of a polyether, methoxy polyethylene glycol (mPEG), a polyacrylate, a polyanhydride, a polyvinyl alcohol, a polysaccharide, a poly(N-vinylpyrrolidone), a polyglycerol (PG), a poly(N-(2-hydroxypropyl)methacrylamide), a polyoxazoline, a poly(amino acid)-basedhybrid, a polyamide, preferably a recombinant polypeptide, a polyester, a polythioester, a polyurethane, a polythiourethane, derivatives, and combinations thereof.

29. The carbon nanoparticle according to claim 27, characterized in that the linear polymeric linker is a polyethylenglycol of the formular:wherein q is an integer of 1 to 1000, preferably n q = 2 to 800, more preferably q = 50 to 600, and even more preferably q = 80 to 400.

30. The carbon nanoparticle according to any of claims 27 to 29, characterized in that the linear polymeric linker is a linear bifunctional polymeric linker having two functional / reactive groups on the two ends of said linear polymer, wherein exemplary functional groups include, but are not limited to, the following: a hydroxyl, a carboxyl, an epoxide, a thiol, an amine, a phosphate, a phosphonate, a sulfate, a sulfite, a sulfonate, a sulfoxide, a sulfone, an amide, an ester, a ketone, an aldehyde, a cyano, a thiocyano, an alkyne, an azide, and an alkene, or a combination thereof.

31. The carbon nanoparticle of claims 2 to 11, characterized in that the quaternary ammonium salt polymer is prepared by introduction of a quaternary nitrogen in a given polymer by one of the following ways of quatemization:(a) Quatemization of a halogen containing polymer with a tertiary amine,(b) Quatemization of a polymeric tertiary amine with an alkyl or aryl halide,(c) Base-catalysed Mannich reaction of a polymeric amide with formaldehyde and dimethylamine followed by quatemization,(d) Quatemization of polymers containing OH-groups by appropriate agents such as 2,3 -epoxypropyltrimethylammonium chloride.

32. The carbon nanoparticle of claims 2 to 11, characterized in that the quaternary ammonium salt polymer is a homopolymer or copolymer made by use of a monomer containing a cationic quaternary ammonium group, whereby said monomer is preferably selected from the group consisting of diallyl dimethyl ammonium chloride (DADMAC), 3-chloro-2-hydroxypropyl methyl diallyl dimethyl ammonium chloride (CMDA), acryloyl oxygen ethyl trimethyl ammonium chloride (DAC), methyl acryloyl oxygenethyl trimethyl ammonium chloride (DMC), acrylamide propyl trimethyl ammonium chloride (APTAC), methyl acrylamide propyl trimethyl ammonium chloride (MAPTAC), N,N-dialkyl-N-2(alkoxycarbonyl)allyl-N-allylammonium chloride, N,N- diallylpyrrolidinium bromide, N,N-diallylisoquinolinium chloride and N,N- diallylmorpholinium bromide.

33. The carbon nanoparticle of claim 32, characterized in that the quaternary ammonium salt polymer is a homopolymer selected from the group consisting of poly-DADMAC, poly-DAC, poly-DMC, poly-APTAC, poly-MAPTAC or a copolymer with acrylamide (AM) as further monomer such as poly(DMDAAC-AM), poly(DAC-AM), poly(DMC- AM), poly(APTAC-AM) and poly(MAPTAC-AM).

34. The carbon nanoparticle of claims 31 to 33, characterized in that the quaternary ammonium salt polymer is a linear polymer, a crosslinked polymer, a branched polymer or a network-forming polymer.

35. Use of the carbon nanoparticle of any of the above claims as an antimicrobial agent, surfactant, stabilizing agent, or preservative.

36. The carbon nanoparticle of any of claims 1 to 34 for use as an antimicrobial agent in the treatment or prevention of an infectious disease in a mammal.

37. The carbon nanoparticle for use according to claim 36, characterized in that the infectious disease is caused by one or more of the following pathogens: bacteria, viruses, fungi, parasites or prions.

38. The carbon nanoparticle for use according to claim 36 or 37, characterized in that the infectious disease is a skin infection or a soft tissue infection.

39. The carbon nanoparticle for use according to claim 38, characterized in that the infectious disease is a fungal skin infection.

40. The carbon nanoparticle of any of claims 1 to 34 for use as an antimicrobial oral care composition for the treatment or prevention of a dental illness selected from the group consisting of plaque, caries, periodontal disease, gingivitis and breath malodor, or combinations thereof.

41. A pharmaceutical composition comprising the carbon nanoparticle of any of claims 1 to 34 and a pharmaceutically acceptable excipient.

42. The pharmaceutical composition of claim 41, characterized in that the pharmaceutically acceptable excipient is selected from the list consisting of diluents / fillers, binders, lubricants, glidants, disintegrants, coating agents, suspending agents, preservatives, antioxidants, buffers, emulsifiers, solubilizers, stabilizers, flavoring agents and coloring agents.

43. The pharmaceutical composition of claim 41 or 42, characterized in that the pharmaceutical composition contains the carbon nanoparticle in a concentration of 0.1 to 100 wt.%, preferably 1 to 50 wt.% and more preferably 10 to 30 wt.%.

44. An antimicrobial composition comprising the carbon nanoparticle of any of claims 1 to 34 and a liquid carrier, wherein the carbon nanoparticle is solubilized or dispersed within the liquid carrier.

45. The antimicrobial composition of claim 44, characterized in that the antimicrobial composition contains the carbon nanoparticle in a concentration of 1 to 50 wt.%, preferably 5 to 40 wt.% and more preferably 10 to 30 wt.%.

46. A cosmetic composition comprising 0.01 to 40 % by weight, preferably between 0.1 to 5.0 % by weight of at least carbon nanoparticle of any of claims 1 to 34 and a dermatologically acceptable carrier.

47. A coating composition for providing an antimicrobial surface comprising the carbon nanoparticle of any of claims 1 to 34 and a film-forming carrier, wherein the filmforming carrier is preferably a polymer or a resin.

48. Antimicrobial device comprising a polymer or resin that contains the nanoparticle of any of claims 1 to 34.

49. Coating composition of claim 47 or antimicrobial device of claim 48, wherein the cationic quaternary ammonium group or quaternary ammonium salt polymer group of the functionalized carbon nanoparticle contains a terminal functional group for binding said carbon nanoparticle to the polymer or resin or even provides a monomer for generating said polymer or resin.

50. Coating composition or antimicrobial device of claim 49, wherein the terminal functional group of the group cationic quaternary ammonium group or quaternary ammonium salt polymer group of the functionalized carbon nanoparticle is preferably selected from the group consisting of hydroxyl groups, alkoxy groups, aryl oxy groups, carbonyl groups, carboxyl groups, epoxide groups, thiol groups, alkyl and aryl sulphide groups, sulphoxide groups, sulphone groups, sulphonyl groups, sulphonamide, thioureas, amines, hydroxylamines, nitriles, nitro groups, cyano groups, N-oxides, hydrazides, azides, enamines and urea groups.

51. Antimicrobial device of claim 48 to 50, characterized in that the polymer or resin contains the nanoparticle of any of claims 1 to 35 in an amount of 0.01 to 25 % by weight, preferably between 0.1 to 5.0 % by weight.

52. The antimicrobial device of claim 48 to 51, characterized in that the antimicrobial device is a medical device and preferably selected from the group consisting of syringes, catheters, stents, abdominal plugs, cotton gauzes, wound dressings, hemostatic materials, adhesive films, contact lenses, lens cases, bandages, sutures, hernia meshes, ostomy and other wound products and breast implants.

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