Process for determining hair fibre properties

Abstract

A method for determining one or more mechanical property of a hair fibre comprising: i. identifying the level of a keratin associated protein in a hair fibre by one or more of the following approaches: a) Direct measurement of protein concentrations in hair fibres; and / or b) Measurement of protein expression in the hair follicle / scalp; and / or c) Measurement of gene expression in the hair follicle / scalp; ii. determining one or more physical properties of the keratin associated protein, the physical properties of the protein selected from the group of the Young's modulus, the radius of gyration, the solvent accessible surface area, the hydration-dependent protein glass transition temperature and / or the water sorption capacity; iii. based on the physical properties of the keratin associated protein and the level of the keratin associated protein, predicting one or more mechanical properties of the hair fibre.

Description

[0001] PROCESS FOR DETERMINING HAIR FIBRE PROPERTIES

[0002] Field of the Invention

[0003] The present invention relates to a method for determining hair fibre properties.

[0004] Background of the Invention

[0005] The soiling of the hair necessitates it being shampooed with frequent regularity. Hair can also suffer from various detrimental properties I conditions. As it is important for consumers for their hair to have a beneficial feel and an attractive appearance it is necessary for a consumer to maintain desirable properties of human hair and to address treatment of detrimental properties thereof.

[0006] This is achieved using a number of scalp and hair treatment formulations; these are usually in the form of a shampoo, to be applied in a washing operation (in a bath or shower) and then removed by rinsing. Post (washing) treatments I formulations may also be applied.

[0007] Understanding the bio-physical and chemical aspects of the bio-substrates that personal care products interact with, as well as the nature of these interactions is critical for optimal design of hair treatment compositions including the selection of individual active(s).

[0008] As part of this an area of interest is the role of scalp health on the condition of the hair fibre. There remains a question as to whether and how scalp condition may influence hair fibre condition.

[0009] One method to study this area would be an in vivo study of hair fibre properties. However, this is recognised to require a large, complex and expensive clinical trial, combined with extensive mechanical measurement of fibre properties.

[0010] Giesen et a / (Giesen M, Gruedl S, Holtkoetter O, Fuhrmann G, Koerner A, Petersohn D reported the details of an exploratory clinical study aimed to characterise age related gene expression changes in hair follicles plucked from young (age 18-24) and older (age 59-66) female volunteers. Amongst other gene pathways, a significant reduction in expression of a number of Keratin Associated Protein (KAP) genes with age was found. Ageing processes have been shown to influence keratin and KAP expression in human hair follicles (Exp Dermatol.

[0011] 2011 Sep;20(9) PMID: 21569108).

[0012] Keratin Associated Proteins (KAPs) are the main component of the matrix, which surrounds the keratin intermediate filaments in the cortex of the hair fibre. KAPs are also present in hair cuticle cells.

[0013] The matrix is therefore a key structural feature to which we should target technology in order to modify the mechanical properties of hair fibres. It is therefore important to obtain a fundamental understanding of the properties of the matrix proteins (KAPs) and how these can be modified with actives.

[0014] However, there is a gap in understanding the impact of these KAP gene level changes on hair fibre mechanical properties.

[0015] Thus, there is a need for an improved method of analysing the role of scalp health on the condition of the hair fibre.

[0016] Summary of the Invention

[0017] According to a first aspect of the invention there is provided a method for determining a hair fibre mechanical property, the method comprising: i. identifying the level of a keratin associated protein in a hair fibre by one or more of the following approaches: - a) Direct measurement of protein concentrations in hair fibres; and I or b) Measurement of protein expression in the hair follicle I scalp; and I or c) Measurement of gene expression in the hair follicle I scalp; ii. determining one or more physical properties of the keratin associated protein, the physical properties of the protein selected from the group of the Young’s modulus, the radius of gyration, the solvent accessible surface area, the hydration-dependent protein glass transition temperature and / or the water sorption capacity; iii. based on the physical properties of the keratin associated protein and the level of the keratin associated protein, predicting one or more mechanical properties of the hair fibre.

[0018] According to a second aspect of the invention there is provided a method for selecting at least one hair fibre treatment active or product, the method comprising: i. identifying the level of a keratin associated protein in a hair fibre by one or more of the following approaches: - a) Direct measurement of protein concentrations in hair fibres; and I or b) Measurement of protein expression in the hair follicle I scalp; and I or c) Measurement of gene expression in the hair follicle I scalp; ii. determining one or more physical properties of the keratin associated protein the physical properties of the protein selected from the group of the Young’s modulus, the radius of gyration, the solvent accessible surface area, the hydration-dependent protein glass transition temperature and / or the water sorption capacity; iii. based on the physical properties of the keratin associated protein and the level of the keratin associated protein, predicting the effect of the keratin associated protein level on one or more mechanical properties of the hair fibre; iv. identifying an active or hair fibre treatment product that can adjust the one or more mechanical properties of the hair fibre.

[0019] According to a third aspect of the invention there is provided a method for determining the effect of a hair fibre treatment active or product on one or more mechanical properties of a hair fibre, the method comprising: i. identifying the level of a keratin associated protein in a hair fibre obtained from a subject to which a hair fibre treatment active or product has been applied in comparison to the level of the keratin associated protein in a control hair fibre obtained from a subject to which the hair fibre treatment active or product has not been applied by one or more of the following approaches: - a) Direct measurement of protein concentrations in hair fibres; and I or b) Measurement of protein expression in the hair follicle I scalp; and I or c) Measurement of gene expression in the hair follicle / scalp; ii. determining one or more physical properties of the keratin associated protein the physical properties of the protein selected from the group of the Young’s modulus, the radius of gyration, the solvent accessible surface area, the hydration-dependent protein glass transition temperature and / or the water sorption capacity; iii. based on the physical properties of the keratin associated protein and the level of the keratin associated protein in the hair fibre of the subject to which the hair fibre treatment active or product has been applied, predicting one or more mechanical properties of the hair fibre of the subject to which the hair fibre treatment active or product has been applied.

[0020] It will be appreciated that the first, second and third aspects of the invention are non-therapeutic and I or cosmetic in nature.

[0021] Preferred features of the first, second and third aspects of the invention are described below. It will be appreciated that features of an aspect of the present invention shall be taken to apply mutatis mutandis to one or more of the other aspects of the present invention.

[0022] The aspects of the invention have been found to be highly advantageous.

[0023] Preferably, step (i) of the first, or second aspects includes identifying the level of a protein in a hair fibre of a subject with a scalp condition in comparison to the level of the protein in a hair fibre of a subject with a healthy, control scalp e.g. without the scalp condition.

[0024] Preferably, one or more steps of the aspects of the invention are performed in-silico (experimentation performed by computer). For example, at least step (ii) and / or (iii) may be performed in silico. This is far easier to perform and more cost effective than a clinical study. This aspect of the invention allows the prediction of numerous hair fibre mechanical properties, including (as a non-limiting list), the following:

[0025] For hair from aged follicles, the cuticle cells would be stiffer and more lifted than those of the control system. The lifted cuticle cells would cause roughness and breakage.

[0026] For hair from a scalp with dandruff, the fibres would not be expected to be stiffer than for a control system. However, stiffness may be lower following octopirox (piroctone olamine) treatment. The endocuticle will be more swellable than for the control system. This may result in more cuticle lift, roughness and breakage. This effect may be reversed following (as an example) octopirox treatment.

[0027] This work permits a transition, completing the knowledge gap, between transcriptomics to properties of protein and fibres and finally to consumer perceivable effects. Beneficially, the methods of the invention allow prediction of the mechanical properties of a hair fibre and how actives may influence the mechanical properties of hair fibres without having to conduct expensive and time-consuming measurement of the hair fibre itself or expensive clinical studies. The methods of the invention beneficially provide an efficient and effective approach to screening hair products / actives influence on mechanical properties of the hair.

[0028] Preferably the method (including step (ii) where present) includes molecular modelling and I or clinical studies. Most preferably, the method includes molecular modelling. This may be used as a pre-screening tool to gain insights into a change in a mechanical property of hair fibres that may be expected to occur in different phenotypes vs a control phenotype.

[0029] Preferably the method (including step (ii) where present) includes molecular modelling. It will be appreciated that this step could (in an alternative) be carried out using a clinical study.

[0030] However, an approach using in silico molecular modelling has the advantage of being quicker, cheaper and easier (than the use of a clinical study).

[0031] As such (with the use of molecular modelling) the method (including step (ii) where present) preferably includes a step of comparing a hair mechanical property and / or consumer perception of a hair mechanical property, between subjects with a chosen scalp condition and subjects with healthy, control scalps. Preferably, the method (including step (i) or (ii) where present) may include a step of comparing the level of a protein of a hair fibre of a subject with a scalp condition and a hair fibre of a subject with a healthy, control scalp.

[0032] Step (i) is achieved by one or more of the following approaches:- a) Direct measurement of protein concentrations in hair fibres; b) Measurement of protein expression in the hair follicle I scalp; c) Measurement of gene expression in the hair follicle / scalp For steps a, b, and I or c, the measurement may be made on a sample taken from a subject with a chosen scalp condition.

[0033] Preferably, the method further comprises a step of comparing the measurement made on a sample taken from a subject with a chosen scalp condition with a measurement made on samples taken from a healthy control scalp.

[0034] For steps a, b, and / or c the protein is a keratin associated protein. Approach c has the (additional) advantage of not requiring a priori knowledge of the proteins to study. The protein is identified from the relevant gene(s). The physical properties of the protein(s) identified from the relevant gene(s) can then be determined by the method of the invention e.g. by performing molecular modeling of the protein(s) coded for by the relevant gene(s).

[0035] The aspects of the invention have been found to be useful in selecting at least one active for use in a hair fibre I scalp treatment product. Thus, the present invention provides a method for selecting at least one active for use in a hair fibre I scalp treatment product comprising the analysis of the result of the methods of any of aspects and preferred features of the invention described above.

[0036] The physical properties of the protein determined in the method of the invention include one or more of: the Young’s modulus (as a function of water content), the radius of gyration (Rg) (as a function of water content) and / or the solvent accessible surface area (as a function of water content).

[0037] Preferably, the Young’s modulus is determined over a consumer relevant strain range. Preferably, the Young’s modulus is determined by assessing changes in stress (bar) for strains of below 0.1.

[0038] Preferably, the physical properties of the protein determined in the method of the invention may also include one or more of hydration-dependent protein glass transition temperature and / or the water sorption capacity of a protein.

[0039] Preferably, the physical properties of the protein may be determined by molecular modelling of the protein. Preferably, the method (including step (ii) where present) includes a step of comparing the physical properties of a protein of a hair fibre to the physical properties of a control protein. In some embodiments, the protein of the hair fibre may be a KAP and the control protein may be a different KAP. For example, the control protein may be a KAP that does not change its gene and / or protein expression with a scalp condition e.g. dandruff or age-related scalp changes. In some preferred embodiments, the control protein can be selected from KAP12.1, KAP13.1 , KAP 5.1 and KAP10.1. Preferably, when assessing the mechanical properties of the endocuticle KAP12.1 or KAP13.1 may be chosen as a control protein. Preferably, when assessing the mechanical properties of the exocuticle KAP 5.1 or KAP10.1 may be chosen as a control protein.

[0040] The method of the invention has been found to have utility in identifying I characterising protein I proteins in a hair fibre.

[0041] The term “hair fibre structural proteins” in the context of this invention denotes hair keratins and keratin-associated proteins.

[0042] Type I hair keratins are acidic and have molecular masses ranging from 40 to 48 kD, and type II hair keratins are basic to neutral and have molecular masses ranging from 58 to 65 kD. As with all intermediate filament subunit proteins, the hair keratins have a common secondary structure that consists of an N-terminal domain; 4 central alpha-helical coiled-coil domains, denoted 1A, 1B, 2A, and 2B; and a C-terminal domain. The non-alpha-helical domains of hair keratins have a high content of cysteine and proline residues, the former reflecting the use of disulfide bonding to produce a tougher, more durable structure. Keratins are obligate heteropolymers, with distinct pairs of type I and type II proteins associating to form heterodimers; these further polymerize to produce the final 10-nm keratin intermediate filament (KIF). Hair keratin genes are differentially expressed in the cuticle and cortex of the hair follicle.

[0043] Keratin-associated proteins (KAPs) are relatively small, hydrophobic proteins possessing either high cysteine or high glycine-tyrosine content, and often have characteristic repeat structures. KAPs form the matrix between the hair KIF bundles through extensive disulfide bond crosslinking with cysteine residues in the head and tail domains of hair keratins. More than 80 individual KAP members are expressed differentially in the hair cortex and cuticle during hair fibre formation. The protein identified may be present in the cortex. Additionally, and I or alternatively the protein identified may be in the endocuticle and / or the exocuticle.

[0044] The protein generally comprises and I or consists of Keratin Associated Protein (KAP).

[0045] Keratin-associated proteins (KAPs) are believed to be important for hair fibre integrity and strength. For example, disorders involving KAP genes have been shown to lead to a reduction in the number of molecules available for KIFs cross-linking, resulting in brittle hair fibres that break easily.

[0046] Examples of preferred Keratin Associated Proteins include the following Keratin Associated Proteins; KAP 1.1, KAP 10.7, KAP 13.2, KAP 26.1 , KAP 4.4, KAP 4.11

[0047] Usually, the gene expression change is related to one or more of the following gene expressions; KRTAP1.1 , KRTAP26.1, KRTAP4.4, KRTAP4.11 , KRTAP10.7, KRTAP13.2.

[0048] Preferred examples of identified I recognised scalp conditions include one or more of dandruff, age related scalp changes, hormone related scalp changes, e.g., scalp changes associated with puberty, pregnancy, pre / post-menopause.

[0049] Preferred examples of identified I recognised hair fibre mechanical property I properties include one or more of stiffness, swellability, frizzing, cuticle lift, breakage, surface roughness, alignment, shine, moisturised feel, styling hold.

[0050] Most preferably, the hair fibre mechanical property I properties include one or more of stiffness, swellability and / or cuticle lift.

[0051] Stiffness may be measured by tensile stress / strain experiments, for example using a Miniature Tensile Tester from Dia-Stron (www.diastron.com). The measurement is usually represented by the Young’s modulus, expressed in GPa. Swellability can be measured by the ratio of the cross- sectional area of wet / dry fibre as a function of time. Frizz may be measured using a Frizz Volume Rig. Image analysis of an area of an image of a hair switch as a function of time may be conducted. Cuticle lift may be measured by visual assessment based on SEM or confocal microscopy (e.g., from Sensofar, www.sensofar.com). Cuticle step height (pm) extracted from SEM or confocal microscopy may be analyzed. Breakage may be measured using a tensile stress / strain experiment, for example using a Miniature Tensile Tester from Dia-Stron (www.diastron.com). Breakage can be represented by Break Stress [gmf / sq micron]. Breakage may also be measured using a fatigue tester (cyclic tensile experiment). Fatigue life is characterized by a statistical analysis of the number of ‘cycles to break’ using a life cycle rig and cyclic combing of a hair switch with counting of the number of broken fibres for a given number of (thousands) of cycles. Surface Roughness may be measured using a texture analyser. A texture analyser measures the resistance to moving a probe over the switch. Alignment may be measured using Rumba (RUMBA - Hair Orientation & Alignment Vizualisation (bossanovavision.com)). This is a polarization imaging system which is sensitive to hair fibre orientation. Output values include, mean, max, min and standard deviation of orientation angle (degrees), and Alignment coefficient (1 / deg.) Shine may be measured using a goniophotometer measuring light scattering by hair fibers. Intensity of scattering and angle (degrees) of scattering may be measured. Moisturised feel may be measured by use of a trained sensory panel who give a score on a linescale. Styling hold may be measured by a style dropout test which measures the time for a switch to lose style.

[0052] The methods of the aspects of the invention may be associated with the use of a composition; such as a hair fibre treatment product or active. Non-limiting features of such a composition are outlined below.

[0053] The composition may not be required and I or certain common actives (such as an anti-dandruff active) may not be present (or at least not present in their conventional amount I concentration). This is because with the use one or more of the methods I aspects of the invention recognised detrimental affect(s) on scalp I hair may be mitigated without the use of conventional actives or with a smaller amount of said conventional actives.

[0054] Compositions

[0055] Suitable personal care compositions for use in the invention include rinse-off or leave-on hair and scalp care compositions such as shampoos, conditioners, creams, lotions, gels, serums, mousses or oils. Rinse-off hair and scalp care compositions such as shampoos and conditioners are preferred.

[0056] Compositions for use in the invention will generally include a cosmetically acceptable vehicle. The term “cosmetically acceptable” means that the vehicle is suitable for topical application to the skin, has good aesthetic properties, and will not cause any safety or toxicity concerns.

[0057] The vehicle may comprise an aqueous phase, an oil phase, an alcohol, a silicone phase or a mixture thereof, and may be in the form of an emulsion. Emulsions can have a range of consistencies including thin lotions (which may also be suitable for spray or aerosol delivery), creamy lotions, light creams and heavy creams.

[0058] Compositions for use in the invention may also be formulated in a single-phase carrier such as a hydrophobic or hydrophilic liquid. Suitable hydrophobic liquid carriers include liquid polyorganosiloxanes, mineral oils, hydrogenated polyisobutene, polydecene, paraffins and isoparaffins of at least 10 carbon atoms, aliphatic or aromatic ester oils (such as isopropyl myristate, lauryl myristate, isopropyl palmitate, diisopropyl sebacate, diisopropyl adipate and C12 to C15 alkyl benzoates), polyglycol ethers (such as polyglycol butanol ethers) and mixtures thereof. Suitable hydrophilic liquid carriers include water, monohydric or polyhydric aliphatic alcohols having 2 to 8, preferably 2 or 3 carbon atoms (such as ethanol and isopropanol, oligoglycol ethers having 2 to 5 repeat units (such as dipropylene glycol) and mixtures thereof.

[0059] Liquid form compositions for use in the invention may be thickened, for example using one or more water soluble or colloidally water soluble polymeric thickening agents. Suitable water soluble or colloidally water soluble polymeric thickening agents include hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polyquaternium-10, carrageenan, guar gum, hydroxypropyl guar gum, xanthan gum, polyvinylalcohol, acrylic acid / ethyl acrylate copolymers, carboxyvinyl polymers, cross-linked polyacrylate polymers and polyacrylamide polymers.

[0060] Preferred types of composition for use in the invention include shampoos, oils and lotions, which are intended for topical application to the hair and scalp.

[0061] Shampoo compositions for use in the invention are generally aqueous (i.e. they have water or an aqueous solution as their major component), and will suitably comprise from 50 to 98%, preferably from 60 to 90% water (by weight based on the total weight of the composition).

[0062] Shampoo compositions for use in the invention will typically comprise one or more anionic surfactants such as sodium oleyl succinate, ammonium lauryl sulfosuccinate, ammonium lauryl sulphate, sodium dodecylbenzene sulfonate, triethanolamine dodecylbenzene sulfonate, sodium cocoyl isethionate, sodium lauryl isethionate, sodium N-lauryl sarcosinate, sodium lauryl sulfate, sodium lauryl ether sulfate (n) EO, (where n ranges from 1 to 3), ammonium lauryl sulfate and ammonium lauryl ether sulfate (n) EO, (where n ranges from 1 to 3) .

[0063] Mixtures of any of the above described materials may also be used.

[0064] The total amount of anionic surfactant in shampoo compositions for use in the invention generally ranges from 5 to 30%, preferably from 8 to 20% (by weight based on the total weight of the composition).

[0065] Shampoo compositions for use in the invention may also include co-surfactants such as nonionic surfactants, which can be included in an amount ranging from 0.5 to 8%, preferably from 2 to 5% (by weight based on the total weight of the composition) and / or amphoteric or zwitterionic surfactants, which can be included in an amount ranging from 0.5 to 8%, preferably from 1 to 4% (by weight based on the total weight of the composition).

[0066] Representative nonionic surfactants include alkanolamides such as cocamide monoethanolamide and cocamide monoisopropanolamide; alkyl polyglucosides such as cocoglucoside and lauryl glucoside; and acyl glucamides such as cocoyl methyl glucamide.

[0067] Mixtures of any of the above described materials may also be used.

[0068] Shampoo compositions for use in the invention may also include one or more cationic polymers, which can be included in an amount ranging from 0.01 to 5%, preferably from 0.05 to 2% (by weight based on the total weight of the composition). Representative cationic polymers include cationic polysaccharide polymers such as cationic cellulose derivatives and cationic guar gum derivatives such as guar hydroxypropyltrimethylammonium chloride.

[0069] Shampoo compositions for use in the invention may also include one or more suspending agents, which can be included in an amount ranging from 0.05 to 5%, preferably from 0.1 to 3% (by weight based on the total weight of the composition). Representative suspending agents include polyacrylic acids, cross-linked polymers of acrylic acid, copolymers of acrylic acid with a hydrophobic monomer, copolymers of carboxylic acid-containing monomers and acrylic esters, cross-linked copolymers of acrylic acid and acrylate esters, heteropolysaccharide gums and crystalline long chain acyl derivatives such as ethylene glycol distearate. Hair oils and lotions for use in the invention typically have an oil phase containing at one or more cosmetically acceptable fatty materials which may be liquid or solid at room temperature (25°C). Lotions are typically aqueous emulsions having an aqueous phase in addition to the oil phase.

[0070] Suitable cosmetically acceptable fatty materials include naturally derived oils (such as sunflower oil, borage oil, soybean oil, castor oil, olive oil and almond oil); esters of monoalcohols or of polyols with monocarboxylic or polycarboxylic acids, at least one of the alcohols and / or acids comprising at least one hydrocarbon-based chain containing at least 6 carbon atoms (such as octyl palmitate, isopropyl myristate, isopropyl palmitate, isopropyl isostearate, hexyl laurate, isohexyl laurate, isohexyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, dihexyldecyl adipate, lauryl lactate, myristyl lactate, cetyl lactate, oleyl stearate, oleyl oleate, oleyl myristate, lauryl acetate, cetyl propionate, isononyl isononanoate, propylene glycol dicaprate, diisopropyl adipate, dibutyl adipate, and oleyl adipate); ethers (such as dicapryl ether); fatty alcohols (such as cetyl alcohol, stearyl alcohol and behenyl alcohol); isoparaffins (such as isooctane, isododecane and isohexadecane); silicone oils (such as cyclomethicone, dimethicone and dimethiconol); hydrocarbon oils (such as mineral oil, petrolatum and polyisobutene); fatty acids containing from 8 to 30 carbon atoms, (such as stearic acid, lauric acid, palmitic acid and oleic acid); vegetable fats (such as cocoa butter, coconut oil, palm oil and shea butter); petroleum-based, natural and synthetic waxes (such as lanolin wax, beeswax, carnauba wax, candelilla wax, paraffin wax, lignite wax, microcrystalline waxes, ceresin, ozokerite, and polyethylene waxes); hydrogenated oils which are solid at 25° C (such as hydrogenated castor oil, hydrogenated jojoba oil, hydrogenated palm oil, hydrogenated tallow and hydrogenated coconut oil) ;and fatty esters that are solid at 25°C (such as C20-40 alkyl stearate).

[0071] The aqueous phase of lotions for use in the invention may also include one or more organic liquids that are miscible with water at room temperature (25°C). Exemplary water-miscible organic liquids include monohydric and polyhydric alcohols and derivatives thereof such as C2- Ce alkanols (such as ethanol and isopropanol); C2-C10 glycols and polyols (such as glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, caprylyl glycol, dipropylene glycol, and diethylene glycol); C3-C16 glycol ethers (such as mono-, di-, or tripropylene glycol (C1-C4) alkyl ethers and mono-, di-, or triethylene glycol (C1-C4) alkyl ethers) and polyethylene glycol having 2 to 12 oxyethylene units. Lotions for use in the invention may also include surface active ingredients, such as emulsifiers and solubilizers, to enable two or more immiscible components to be combined homogeneously and to help stabilize the composition. Emulsifiers that may be used to form O / W or W / O emulsions include sorbitan oleate, sorbitan sesquioleate, sorbitan isostearate, sorbitan trioleate, PEG-20 sorbitan isostearate, polyglyceryl-3-diisostearate, polyglycerol esters of oleic / isostearic acid, polyglyceryl-6 hexaricinolate, polyglyceryl-4-oleate, polyglyceryl-4 oleate / PEG-8 propylene glycol cocoate, polyglyceryl-2 dipolyhydroxystearate, PEG-30 dipolyhydroxystearate, oleamide DEA, TEA myristate, TEA stearate, magnesium stearate, sodium stearate, potassium laurate, potassium ricinoleate, sodium cocoate, sodium tallowate, potassium castorate, sodium oleate, cetyl phosphate, diethanolamine cetyl phosphate, potassium cetyl phosphate, sodium glyceryl oleate phosphate, dimethicone copolyol, cetyl dimethicone copolyol, octyldimethicone ethoxyglucoside copolyol, dimethicone copolyol crosspolymer and laurylmethicone copolyol.

[0072] Combinations of any of the above described materials or product forms may also be used.

[0073] Compositions for use in the invention (as described above) may include additional actives for improving the physical and / or aesthetic characteristics of the scalp and / or the hair. Examples include amino acids, vitamins, minerals and / or antioxidants, emollients, humectants, sunscreens, anti-irritants, exfoliating agents, botanical extracts (such as pomegranate, white birch, green tea, chamomile and licorice extracts) and mixtures thereof.

[0074] Compositions for use in the invention (as described above) may include additional functional ingredients for improving the physical and / or aesthetic characteristics of the composition perse. Examples include inorganic pigments (such as titanium oxide, zirconium oxide, cerium oxide, zinc oxide, iron oxide, chromium oxide, manganese violet, ultramarine blue, chromium hydrate and ferric blue); organic pigments (such as carbon black and the organic lakes of barium, strontium, calcium or aluminium); pearlescent agents (such as mica coated with titanium oxide and / or iron oxide); dyes, preservatives (such as disodium EDTA, benzyl alcohol, methylparaben, phenoxyethanol, propylparaben, ethylparaben, butylparaben and isobutylparaben); pH adjusters and fragrances (such as essential oils, flower oils, natural extracts from resins, gums, balsams, beans, mosses and other plants, as well as synthetic aromatic materials).

[0075] It is preferred that the haircare compositions comprise 0.5 to 5 wt percent of an antidandruff agent. Preferably the photolabile antidandruff agent is a particulate is zinc-based antidandruff agent.

[0076] More preferably the zinc based antidandruff agent is zinc pyrithione.

[0077] An additional antidandruff agent may be present.

[0078] The additional antidandruff agent is preferably selected from azoles, Octopirox(R)(piroctone olamine), selenium sulfide, salicylic acid and combinations thereof. Azoles include ketoconazole and climbazole, preferably climbazole.

[0079] The haircare compositions of the invention may further comprise a zinc salt. The additional zinc salt may suitably be selected from zinc salts of organic acids, zinc salts of inorganic acids, zinc oxides, zinc hydroxides or a mixture thereof.

[0080] Examples of preferred zinc salts include zinc oxide, zinc pyrrolidone carboxylic acid, zinc citrate, zinc carbonate, zinc chloride, zinc sulphate, zinc glycinate, zinc acetate, zinc lactate, and mixtures thereof. When present, it is preferred that the haircare compositions of the invention comprise 0.1 to 5 wt percent, preferably 0.2 to 3 wt percent, more preferably from 0.25 to 2.5 wt percent of the salt based on the total weight of the composition.

[0081] Mixtures of any of the above described materials may also be used.

[0082] Packaging and Use

[0083] Beneficially, the methods of the invention allow the identification of the effect of a hair fibre treatment active and / or product on the mechanical properties of a hair fibre. Additionally, the methods of the invention allow the identification of hair fibre treatment actives and / or products for mitigating or reversing the effect of proteins (e.g. KAPs and / or Keratins) on mechanical properties of a hair fibre. For example, the methods of the invention identify the effect of actives such as piroctone olamine on the mechanical properties of the hair fibre.

[0084] The invention further relates to the use of piroctone olamine for increasing the gene expression of KRTAP 1.1 , KRTAP 13.2 and / or KRTAP 4.4, preferably for increasing the gene expression of KRTAP 1.1 and / or KRTAP 4.4. The invention further provides use of piroctone olamine for increasing the expression of KAP1 .1 , KAP13.2 and / or KAP 4.4 in a hair fibre, preferably for increasing the expression of KAP1.1 and / or KAP 4.4 in a hair fibre. Preferably, the invention provides use of piroctone olamine for reducing the stiffness, swellability and / or cuticle lift of a hair fibre, more preferably for reducing the stiffness and / or swellability of a hair fibre. In some embodiments, the invention relates to use of piroctone olamine for reducing stiffness of a hair fibre, such as reducing stiffness of the exocuticle of a hair fibre. In some embodiments, the invention relates to use of piroctone olamine for reducing swellability of a hair fibre, more preferably reducing the swellability of the endocuticle of a hair fibre. Most preferably, the invention provides use of piroctone olamine for reducing the stiffness of the exocuticle of a hair fibre and / or for reducing the swellability of the endocuticle of a hair fibre. In some embodiments, the invention relates to use of piroctone olamine for reducing stiffness of the hair fibre by increasing the expression of KAP1.1 in a hair fibre, preferably in the exocuticle of a hair fibre. In some embodiments, the invention relates to use of piroctone olamine for reducing swellability of the hair fibre by increasing the expression of KAP4.4 in a hair fibre, preferably in the endocuticle of a hair fibre.

[0085] In some embodiments the invention relates to use of piroctone olamine for one or more of reducing split ends, reducing the dullness of hair, reducing the dryness of hair, improving the softness of hair, improving the clean feel of hair. In some embodiments, the invention relates to use of piroctone olamine for one or more of reducing split ends and / or improving the softness of hair.

[0086] Preferably, the use is non-therapeutic and / or cosmetic.

[0087] In some embodiments the invention relates to piroctone olamine for use in a method of increasing the gene expression of KRTAP 1.1 , KRTAP 13.2 and / or KRTAP 4.4, preferably for increasing the gene expression of KRTAP 1.1 and / or KRTAP 4.4. The invention further provides piroctone olamine for use in a method of increasing the expression of KAP1.1 , KAP13.2 and / or KAP 4.4 in a hair fibre, preferably increasing the expression of KAP1.1 and / or KAP 4.4 in a hair fibre. Preferably, the invention provides piroctone olamine for use in a method of reducing the stiffness, swellability and / or cuticle lift of a hair fibre, more preferably a method of reducing the stiffness and / or swellability of a hair fibre. In some embodiments, the invention relates to piroctone olamine for use in a method of reducing stiffness of a hair fibre, such as reducing stiffness of the exocuticle of a hair fibre. In some embodiments, the invention relates to piroctone olamine for use in a method of reducing swellability of a hair fibre, more preferably reducing the swellability of the endocuticle of a hair fibre. Most preferably, the invention provides piroctone olamine for use in a method of reducing the stiffness of the exocuticle of a hair fibre and / or for reducing the swellability of the endocuticle of a hair fibre. In some embodiments, the invention relates to piroctone olamine for use in a method of reducing stiffness of the hair fibre by increasing the expression of KAP1.1 in a hair fibre, preferably in the exocuticle of a hair fibre. In some embodiments, the invention relates to piroctone olamine for use in a method of reducing swellability of the hair fibre by increasing the expression of KAP4.4 in a hair fibre, preferably in the endocuticle of a hair fibre.

[0088] In some embodiments the invention relates to piroctone olamine for use in a method of one or more of reducing split ends, reducing the dullness of hair, reducing the dryness of hair, improving the softness of hair, improving the clean feel of hair. In some embodiments, the invention relates to piroctone olamine for use in a method of one or more of reducing split ends and / or improving the softness of hair.

[0089] A composition for use in the invention (as described above) may be packaged in a suitable container to suit its viscosity and intended use by the consumer. For example, a liquid composition can be packaged in a bottle or tube, or in a container fitted with a pump suitable for finger operation, or in a propellant-driven aerosol device. Gel or cream compositions can be packaged in a non-deformable bottle or squeeze container, such as a tube or a lidded jar, or in an applicator having a dispensing head provided with at least one aperture through which the composition can be extruded under mild pressure.

[0090] The composition is suitably applied to the hair and scalp and massaged into the surface of the scalp. Generally, an amount corresponding to about 1 to 15 ml of the composition per application is applied uniformly over the area of treatment daily or at least once a week over a time interval of at least 7 (seven) days, more preferably at least 30 (thirty) days.

[0091] The invention shall be described further with reference to the following non-limiting examples.

[0092] Examples

[0093] Choice of KAPs

[0094] Transcriptomics studies demonstrated that ageing process and scalp condition of dandruff reduce gene expression of certain KAPs in hair follicles. These molecular alterations in KAPs were more pronounced with aging. In humans, about 100 KAP genes have been identified. From 69 KAP genes detected in plucked hair follicles by RNAseq analysis, 30 were significantly down-regulated in aged compared to young group (see Figure 1), accounting for over 40% of detected KAP genes. In the dandruff study, 66 KAP genes were detected in scalp biopsies, of which 4 were significantly reduced in dandruff compared to healthy samples, and further 51 showed weak down-regulation trend.

[0095] The KAPs studied (test systems) in this work were chosen from KAPs that correspond to genes which demonstrated the most significant level of change in the phenotypes studied. Additionally, localisation of chosen KAPs within the cuticle layers was considered, to include KAPs representing both endocuticle and exocuticle localisation to enable modelling of their respective fibre property. Reference (control) systems were chosen from KAPs which are in the same parts of the hair structure as the test KAPs, but for which the corresponding genes do not change their expression between the phenotypes studied.

[0096] The KAPs showing the most significant differences in expression in different scalp conditions are summarised below.

[0097] Phenotype 1 is aged hair

[0098] Phenotype 2 is dandruff affected scalp

[0099] The following gene expression changes were observed:

[0100] KRTAP1.1 - down-regulated in aged plucked hair follicles (phenotype 1); no significant change in dandruff (phenotype 2), up-regulated following octopirox shampoo treatment

[0101] KRTAP26.1 - no significant change with age (phenotype 1); down-regulated in dandruff affected scalp, but not significantly reversed by octopirox

[0102] KRTAP4.4 - down-regulated in aged plucked hair follicles (phenotype 1); no significant change in dandruff (phenotype 2), up-regulated following octopirox shampoo treatment

[0103] KRTAP4.11 - no significant change in aged hair or dandruff, but up-regulated following octopirox shampoo treatment

[0104] KRTAP10.7 - no significant change in aged hair; down-regulated in dandruff and up-regulated following octopirox treatment

[0105] KRTAP13.2 - no significant change in aged hair; down-regulated in dandruff and up-regulated following octopirox treatment Choice of Physical Parameters to Model

[0106] The KAPs that correspond to genes that change their expression between the scalp conditions are as follows,

[0107] KAPs 1.1, 10.7, 13.2, 26.1, 4.4, 4.11.

[0108] These are all expressed in the cuticle of the hair fibre. This is the outer layer of the hair fibre, as shown in Figure 2. The SEM image in Figure 2 shows that the cuticle consists of an overlapping tiled structure.

[0109] Each tile is a cuticle cell, consisting of an upper layer of exocuticle and a lower layer of endocuticle, as shown in Figure 3.

[0110] The exocuticle is the hardest part of the hair fibre, it is tough and inflexible. The endocuticle is more flexible and shows a high level of swelling in water. Swelling in the endocuticle can lead to cuticle lift which can lead to fibre damage during grooming. We therefore need to consider the location of the KAPs in the cuticle structure and the physical properties that are relevant in this location. The following locations for the KAPs of interest have been identified,

[0111] KAP1.1 Exocuticle

[0112] KAP26.2 Endocuticle

[0113] KAP4.4, KAP4.11 Endocuticle or Exocuticle

[0114] The remainder are mainly Endocuticle.

[0115] For the exocuticle, the property of interest is the stiffness of the protein. In the modelling work this is tested by calculating the Young’s modulus of the KAP system.

[0116] For the endocuticle, the property of interest is the swelling of the KAP system. In the modelling work this can be assessed by equilibrating the KAPs with different levels of water. There are a number of ways in which the size of the KAPs can then be assessed. The first is the radius of gyration, Rg, which is given by the following equation

[0117] Rd = ( imirf / M') Where M=^jmj, and n is the distance of mass element mi from the axis of rotation

[0118] The second is the Solvent Accessible Surface Area (SASA). This is a measure of the area of the molecule that is accessible to a solvent molecule (see Figure 4). The SASA, can either be calculated for each KAP separately, giving a mean value for the system, or for the KAP aggregate as a whole. For this reason, the SASA of the aggregate will be the property that is discussed in the rest of this document. This property was also preferred over Rg on the basis that Rg is relatively insensitive.

[0119] The chosen properties to model are therefore the Young’s modulus for the exocuticle related KAPs and the swelling property (ratio of the SASA of the aggregate under 2 different hydration conditions) for the endocuticle related KAPs. For KAPs present in both structures, both properties were modelled as a function of water content in the relevant structure.

[0120] Choice of Test and Reference Systems

[0121] The test systems were,

[0122] KAP1.1 for exocuticle. This was chosen because, according to reference (Koehn, H., Clerens, S., Deb-Choudhury, S., Morton, J. D., Dyer, J. M., Plowman, J. E., Journal of Proteomics 73, 2009, 323-330, doi: 10.1016 / j.jprot.2009.09.017) this was only in the exocuticle.

[0123] KAP26.1 for the endocuticle. This was chosen because, according to the reference above this was the KAP that was most clearly in the endocuticle, with little evidence for its presence in the exocuticle.

[0124] The reference (control) systems were chosen from the KAPs that don’t change their gene expression between the scalp conditions. For endocuticle these are KAP12.1 or KAP13.1 , for exocuticle KAP 5.1 or KAP10.1. KAP12.1 and KAP5.1 were chosen.

[0125] Other KAPs

[0126] These are KAPs that do change their gene expression between the scalp states, but where the endocuticle I exocuticle distinction is less clear. Both hardness and swelling were considered. These are KAPs 10.7, 13.2, 4.4 and 4.11. Choice of pH Conditions

[0127] For the endo (and exo) cuticle, pH7 was chosen because the endocuticle can exchange water with the environment. So, after washing and rinsing it should be at pH7. pH 7 was therefore used.

[0128] Choice of Hydration Conditions

[0129] Endocuticle

[0130] It is postulated that endocuticle KAPs may hold more water per unit mass than cortex KAPs, and when the hair is washed the figure could be even higher. For this reason, an upper limit of ‘100%’ water (i.e. , water in massive excess of protein) was chosen.

[0131] At 50% RH, the water content of hair is -13% w / w for water on hair fibre. This is equivalent to -26% w / w water / KAP.

[0132] The water contents used for endocuticle were therefore 0%, 26% and 100%.

[0133] Exocuticle

[0134] The exocuticle contains - 15% cysteine and was expected to have a very low swellability. For this reason, the water concentrations chosen were 0% and 10%. In addition, the ‘100% water’ condition was also run.

[0135] 1. Stages of The Study

[0136] The primary structure of the KAP is the amino acid sequence available from public domain websites. This is shown in Figure 5. As indicated above, the work is carried out at pH7. Disulphide bonds are not included in the structure. This is partly because the locations of the bonds are not known (in the physical system they could be inter- or intra- molecular) and partly because the extra rigidity imposed by these bonds may prevent effects from being seen on timescales that can be modelled. KAP1.1 - No. amino acids = 177

[0137] MACCQTSFCGFPSCSTSGTCGSSCCQPSCCETSSCQPRCCETSCCQPS CCQ.TSFCGFPSFSTGGTCDSSCCQPSCCETSCCQPSCYQ.TSSCGTGCGI GGGIGYGQEGSSGAVSTRIRWCRPDCRVEGTCLPPCCVVSCTPPSCC QLHHAEASCCRPSYCGQSCCRPVCCCYCSEPTC

[0138] The next stage was to equilibrate the KAP structures both in vacuum (dry) and in water. This is shown in Figure 6. The equilibration is carried out using the CHARMM force field with the SPC / E water model.

[0139] The next stage was to carry out the molecular dynamics modelling, allowing the KAPs to equilibrate their structures in both vacuum (dry) and water. Equilibration can be monitored by studying the radius of gyration (Rg) or the Solvent Accessible Surface Area (SASA) as a function of simulation time (Figure 7).

[0140] The KAP structure at ‘100%#’ water can then be used as the starting point for re-equilibrating at the appropriate water content (Figure 8). Again, the re-equilibration can be monitored by studying Rg or SASA.

[0141] * Note that 100% water or 99.9% water are both used equivalently to mean in a large excess of water.

[0142] For KAPs that occur in the exocuticle, the next stage was to determine the Young’s modulus. This was carried out using a uniaxial pulling experiment. The simulations are run at 298K and 1 atmosphere. The uniaxial pulling rate in z the direction was set at 0.0005 nm / ps = 0.5 m / s. Note that this strain rate is set by limitations on the modelling conditions and is much higher than those expected in consumer relevant experience or physical experiment. The pressures in the x and y directions are maintained constant throughout the experiment. The strain results in a reduction in pressure in the z direction. This is the opposite of the applied stress that would be needed to obtain this level of strain. This is illustrated in Figures 9 and 10. The initial simulations were carried out over a wide strain range (Figure 9). To obtain the Young’s modulus over consumer relevant strain range, the change in stress was studied for strains below 0.1 (Figure 10).

[0143] The lines fitted to the plots give the moduli as follows, Table 1

[0144] For KAPs relevant to the endocuticle, the swelling was studied by calculating the Rg and SASA as a function of water content. Results are shown in Figure 11.

[0145] Results

[0146] Tensile Properties

[0147] Tensile Properties of KAPs Found in Exocuticle

[0148] The Young’s Modulus (derived from tensile properties) is used as a measure of the hardness / stiffness of the hair fibre cuticle. The values for the test system (KAP1.1 , a KAP that shows different gene expression in the scalp conditions) and the control system (KAP5.1 , a KAP that does not show different gene expression in the different scalp conditions) are presented in Figure 12.

[0149] The control system (KAP5.1) showed no effect of water on modulus. The test system (KAP1.1) has the same modulus as the control KAP when dry but shows a large reduction in modulus at 10% water. KAP1.1 is therefore water sensitive.

[0150] KAP4.11 occurs in both endo and exo cuticle. KAP10.7 is mainly in the endocuticle, but to some extent in exocuticle. The values of their Young’s moduli as a function of water content are shown in Figure 13.

[0151] The modulus of KAP10.7 is not sensitive to the presence of water between dry and 26% water (the levels relevant to the endocuticle) and was therefore not studied at 10% water (relevant to the exocuticle).

[0152] The modulus of KAP4.11 at 26% water is ~ half that of dry KAP4.11. Because of this sensitivity, this KAP was also assessed at 10% water. This value is not significantly different from that of the Dry KAP. Also, note that the moduli for Dry KAP4.11 , KAP4.11 in 10% water, Dry KAP10.7 and KAP10.7 in 26% water are all similar.

[0153] Swelling Properties

[0154] Swelling Properties: Solvent Accessible Surface Area (SASA)

[0155] Figure 14 and Table 2 below present an overview of the SASA data for all of the KAPs. The SASA values used here are those of the aggregates. In order to assess the amount by which each KAP has swollen, the SASA of each KAP has been normalised to the corresponding SASA for the KAP aggregate at 0% water. As discussed above, disulphide bonds have not been included in this work. Because the exocuticle and endocuticle may have very different levels of disulphide bonding, the values for the two sets of KAPs cannot be compared with each other. Analysis should therefore be restricted to comparisons within the two sets of KAPs.

[0156] These comparisons are shown in Figures 15 to 17.

[0157] Figure 15 shows the data for the test and reference systems for the exocuticle. In this case both KAPs show a very similar amount of swelling at 100% water, but very different amounts at 10% water (for which the test system, KAP1.1 swells more). However, in the cuticle the KAPs are probably extensively cross-linked by disulphide bonds, so this comparison of swelling properties is probably not very meaningful.

[0158] Figure 16 shows the data for the test and reference systems for the endocuticle. In this case the test system (KAP26.1) swells much less than the control system (KAP12.1).

[0159] Figure 17 shows the data for the KAPs that may be present in both the endocuticle and the exocuticle. As stated above, the different levels of disulphide bonding present in the cuticle and exocuticle make comparison between the two regions difficult. However, as swelling is primarily of interest in the endocuticle, data for test and reference systems for the endocuticle are also included. The swelling behaviours of KAPs 4.4, 4.11 and 13.2 are between those of endocuticle test system (which is the lower bound) and endocuticle reference system (upper bound).

[0160] KAP10.7 has similar behaviour as the endo reference KAP at 100% water but has a much lower level of swelling at 26% water. KAP4.11 shows the largest swelling of any of the KAPs at 26% water. Table 2

[0161] Summary of Findings for Phenotype 1 (Aged. Plucked Hair Follicles)

[0162] The following analysis assumes that changes in gene expression in the follicle are reflected in protein expression in the hair fibre.

[0163] Stiffness

[0164] KRTAP1.1 had a lower gene expression level in phenotype 1 than in control

[0165] KAP1.1 occurs in the exocuticle

[0166] KAP1.1 has a lower Young’s modulus at 10% water content than the exocuticle reference KAP In phenotype 1 there would be less KAP1.1, therefore the exocuticle would remain stiffer than the control at 10% water content

[0167] Swelling

[0168] KAP1.1 swells more at 10% water content than the cuticle reference KAP

[0169] In phenotype 1 there would be less KAP1.1, therefore the exocuticle may be less swellable. However, this may not be relevant in the case of exocuticle because of the high level of disulphide bonding.

[0170] KRTAP4.4 had a lower gene expression level in phenotype 1 than in control

[0171] KAP4.4 occurs in both exocuticle and endocuticle

[0172] KAP4.4 is less swellable than the reference KAP for the endocuticle

[0173] In phenotype 1 there would be less KAP4.4, therefore the endocuticle would be more swellable than the control at 10% water content. Summary of Findings for Phenotype 2 (Dandruff. Scalp Skin)

[0174] As above, this analysis assumes that changes in gene expression in the follicle are reflected in protein expression in the hair fibre.

[0175] Stiffness

[0176] KRTAP1.1 showed no significant change in expression in phenotype 2. However, it is up- regulated following octopirox shampoo treatment

[0177] KAP1.1 occurs in the exocuticle

[0178] KAP1.1 has a lower Young’s modulus at 10% water content than the exocuticle reference KAP In phenotype 2 followed by octopirox treatment, there would be more KAP1.1, therefore the exocuticle would be less stiff than the control at 10% water content.

[0179] Hair fibers with stiff endocuticles may be associated with split ends and / or low softness of the hair. Reducing the stiffness of the hair may be desirable for improving these and associated hair properties.

[0180] Swelling

[0181] KRTAP26.1 had a lower gene expression level in phenotype 2 than in control (this was not significantly reversed by octopirox)

[0182] KAP26.1 occurs in the endocuticle

[0183] KAP26.1 is less swellable than the reference KAP for the endocuticle

[0184] In phenotype 2 there would be less KAP26.1 , therefore the endocuticle would be more swellable. Octopirox treatment would not be expected to reverse this swelling.

[0185] KRTAPP13.2 had a lower gene expression level in phenotype 2 than in control. It is up- regulated following octopirox shampoo treatment

[0186] KAP13.2 occurs (mainly) in the endocuticle

[0187] KAP13.2 is less swellable than the reference KAP for the endocuticle

[0188] In phenotype 2 there would be less KAP13.2, therefore the endocuticle would be more swellable than the control. This would be reversed following octopirox treatment.

[0189] KRTAP4.4 shows no significant difference in expression in phenotype 2 compared with control.

[0190] However, it is up-regulated following octopirox shampoo treatment

[0191] KAP4.4 occurs in both exocuticle and endocuticle

[0192] KAP4.4 is less swellable than the reference KAP for the endocuticle In phenotype 2 followed by octopirox treatment there would be more KAP4.4, therefore the endocuticle would be less swellable than the control at 10% water content.

[0193] Hair fibers with a swellable endocuticles may be associated with split ends, dullness of the hair, dryness of the hair, low softness of the hair and / or lack of clean feel of the hair. Therefore, reducing the swellability of the hair may be desirable for improving these properties of the hair.

[0194] Figure 1 shows a summary of HAI-BIO-1396 and HAI-BIO-3252 study designs and reported changes in KAPs gene expression.

[0195] Figure 2 shows the hair fibre and cuticle.

[0196] Figure 3 shows a cross section through the cuticle.

[0197] Figure 4 shows the solvent accessible surface area (SASA).

[0198] Figure 5 shows the primary structure of KAP1.1 : sequence and initial structure.

[0199] Figure 6 shows obtaining the initial configuration of the KAP in vacuum and in water.

[0200] Figure 7 shows equilibration of the structure of KAP1.1 in ‘100%’ Water

[0201] On the left is a plot of Rg for KAP 1 .1 vs simulation time (also shown is the equivalent for KAP26.1). On the right is the structure of KAP1.1 after 50ns.

[0202] Figure 8 shows re-Equilibration of the KAP Structure at the chosen water levels

[0203] The system on the left consists of 16 KAP1.1 molecules assembled from the structure obtained in ‘100% water’. The system on the right is the result of re-equilibrating at 10% water.

[0204] Figure 9 shows uniaxial pulling simulation for KAP1.1. Here the strain has been extended to very high (unrealistic levels). The area of interest for determining the Young’s modulus is the low strain region (strain<0.1), as in Figure 10. Figure 10 shows determination of Young’s Modulus for KAP1.1 from uniaxial pulling simulation over low strain region.

[0205] Figures 11a to 11c show KAP swelling as a function of water Content (0%, 26% and ‘100%’).

[0206] 11.a. Measured by Radius of Gyration (Rg)

[0207] 11.b. Measured by Solvent Accessible Surface Area (SASA) from Total KAPs / No. KAPs

[0208] 11.c. Measured by Average SASA of each KAP Considered Individually

[0209] Figure 12 shows the values of Young’s modulus for the Test System (KAP1.1) and the Control System (KAP5.1) for KAPs in the exocuticle.

[0210] Figure 13 shows Young’s modulus for KAP 4.11 and KAP10.7 as a function of water content.

[0211] Figure 14 shows an overview of the SASA for each KAP, normalised to the corresponding value at 0% water.

[0212] Figure 15 shows SASAs for the Test (KAP1.1) and Reference (KAP5.1) Systems relevant to the exocuticle. Values are normalised to the corresponding values at 0% water.

[0213] Figure 16 shows SASAs for the Test (KAP26.1) and Reference (KAP12.1) Systems relevant to the endocuticle. Values are normalised to the corresponding values at 0% water.

[0214] Figure 17 shows SASAs for the KAPs that may be present in both endocuticle and exocuticle. Values are normalised to the corresponding values at 0% water. For comparison, the Test and Reference Systems for the Endocuticle are also included.

Claims

Claims1. A method for determining one or more mechanical properties of a hair fibre, the method comprising: i. identifying the level of a keratin associated protein in a hair fibre by one or more of the following approaches: - a) Direct measurement of protein concentrations in hair fibres; and I or b) Measurement of protein expression in the hair follicle I scalp; and I or c) Measurement of gene expression in the hair follicle I scalp; ii. determining one or more physical properties of the keratin associated protein, the physical properties of the protein selected from the group of the Young’s modulus, the radius of gyration, the solvent accessible surface area, the hydrationdependent protein glass transition temperature and / or the water sorption capacity; iii. based on the physical properties of the keratin associated protein and the level of the keratin associated protein, predicting one or more mechanical properties of the hair fibre.

2. A method for selecting at least one hair fibre treatment active or product, the method comprising: i. identifying the level of a keratin associated protein in a hair fibre by one or more of the following approaches: - a) Direct measurement of protein concentrations in hair fibres; and I or b) Measurement of protein expression in the hair follicle I scalp; and I or c) Measurement of gene expression in the hair follicle I scalp; ii. determining one or more physical properties of the keratin associated protein the physical properties of the protein selected from the group of the Young’s modulus, the radius of gyration, the solvent accessible surface area, the hydration-dependent protein glass transition temperature and / or the water sorption capacity; iii. based on the physical properties of the keratin associated protein and the level of the keratin associated protein, predicting the effect of the keratin associated protein level on one or more mechanical properties of the hair fibre; iv. identifying an active or hair fibre treatment product that can adjust the one or more mechanical properties of the hair fibre.

3. A method for determining the effect of a hair fibre treatment active or product on one or more mechanical properties of a hair fibre, the method comprising: i. identifying the level of a keratin associated protein in a hair fibre obtained from a subject to which a hair fibre treatment active or product has been applied in comparison to the level of the keratin associated protein in a control hair fibre obtained from a subject to which the hair fibre treatment active or product has not been applied by one or more of the following approaches: - a) Direct measurement of protein concentrations in hair fibres; and I or b) Measurement of protein expression in the hair follicle I scalp; and I or c) Measurement of gene expression in the hair follicle I scalp; ii. determining one or more physical properties of the keratin associated protein the physical properties of the protein selected from the group of the Young’s modulus, the radius of gyration, the solvent accessible surface area, the hydration-dependent protein glass transition temperature and / or the water sorption capacity; iii. based on the physical properties of the keratin associated protein and the level of the keratin associated protein in the hair fibre of the subject to which the hair fibre treatment active or product has been applied, predicting one or more mechanical properties of the hair fibre of the subject to which the hair fibre treatment active or product has been applied.

4. A method according to claim 1, 2 or 3, wherein the method includes molecular modelling of the protein.

5. A method according to any of the preceding claims wherein the physical property of the protein is selected from one or more of: the Young’s modulus as a function of water content, the radius of gyration as a function of water content, the solvent accessible surface area as a function of water content, the hydration-dependent protein glass transition temperature, the water sorption capacity.

6. A method according to any of the preceding claims wherein the mechanical property of the hair fibre is selected from the stiffness, swellability, cuticle lift, rigidity, styling hold, frizzing, breakage, surface roughness, shine and / or moisturised feel of a hair fibre.

7. A method according to any of the preceding claims, wherein for steps a, b, and I or c, the measurement is taken from a sample taken from a subject with a scalp condition; preferably, the method further comprises a step of comparing the sample taken from a subject with a scalp condition with a measurement made on a sample taken from a healthy, control scalp.

8. A method according to any of the preceding claims, wherein the protein is a protein identified is in the cortex, endocuticle or exocuticle.

9. A method according to any of the preceding claims wherein the protein is a Keratin Associated Protein comprising one or more of the following Keratin Associated Proteins; KAP 1.1, KAP 10.7, KAP 13.2, KAP 26.1, KAP 4.4, KAP 4.11.

10. A method according to any of the preceding claims, wherein the gene expression is of one or more of the following genes; KRTAP1.1 , KRTAP26.1, KRTAP4.4, KRTAP4.11 , KRTAP10.7, KRTAP13.2.

11. A method according to any one of claims 7 to 10, wherein the scalp condition includes one or more of dandruff, age related scalp changes, hormone related scalp changes, e.g., scalp changes associated with puberty, pregnancy, pre / post-menopause.

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