Methods of protecting hair and skin

Abstract

Provided herein are methods for protecting and preventing hair damage or hair color loss from UV light. Provided herein are methods for protecting and preventing damage to scalp from UV light. In some embodiments, the methods comprise applying a composition of compounds or polymers thereof as described herein.

Description

WSGR Docket No. 63230-733.601METHODS OF PROTECTING HAIR AND SKINCROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 738,104, filed December 23, 2024, which is hereby incorporated by reference in its entirety herein.BACKGROUND

[0002] Hair is susceptible to damage from exposure to ultraviolet (UV) light, such as UVA and UVB light. When hair is exposed to UV light over varying periods of time, hair may lose its integrity (such as strength, elasticity, shine) as well as color. Hair proteins may undergo protein degradation, such as oxidative damage through oxidation of aromatic residues in hair proteins, which contributes to loss of hair integrity. Hair dyes may also undergo oxidation, resulting in changes in hair color. In some cases, oxidation of hair dyes may lead to a tarnished color, which may affect a subject’s confidence and self-image.

[0003] Additionally, skin, such as scalp on the head, may also undergo damage from exposure to UV light. For example, skin may become discolored and more susceptible to developing melanomas when skin has been exposed to UV light for extended periods of time. Further, UV light can cause DNA damage that negatively affects properties and processes of skin, such as collagen production.SUMMARY

[0004] Described herein are methods for protecting hair and preventing hair color loss due to UV exposure. Described herein are methods for protecting scalp due to UV exposure. In some embodiments, the methods described herein provide applying a composition that protects hair from UV. In some instances, the composition comprises compounds or polymers thereof. As such, the composition may be biocompatible. The instant disclosure also provides methods for protecting hair comprising applying a composition, wherein the compounds or polymers thereof are substantially colorless. Accordingly, the methods described herein provide an advantage of protecting hair from UV light, such as UVA and UVB, without altering the underlying color of hair (due to application of the composition).

[0005] Described herein are also methods for protecting skin, such as scalp, due to UV exposure. In some embodiments, the method for protecting skin, such as scalp, comprisesWSGR Docket No. 63230-733.601administering a composition comprising compounds or polymers thereof. The methods for protecting skin, such as scalp, as described herein provide the advantage of protecting skin, such as scalp, from UV light, such as UVA and UVB, without changing the underlying color of skin (due to application of the composition).

[0006] In some aspects, provided herein are methods of protecting hair of a subject from damage by ultraviolet (UV) light, the method comprising: applying a composition to the hair H the subject, the composition comprising a compound having the structure: HO'" \ / '"' / (Compound 1), (Compound 3),polymer thereof, or a combination of two or more thereof. In some embodiments, the damage is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, or a combination thereof.

[0007] In some aspects, provided herein are methods of preventing discoloration of hair of a subject, the method comprising: applying a composition to the hair of the subject, the HOcomposition comprising a compound having the structure:HOWSGR Docket No. 63230-733.601some embodiments, the damage is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay.

[0008] In some aspects, provided herein are methods of preventing loss of color from hair, the method comprising: applying a composition to the hair, the composition comprising aWSGR Docket No. 63230-733.601combination of two or more thereof. In some embodiments, the loss is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0009] In some aspects, provided herein are methods of preventing breakage of hair, the method comprising: applying a composition to the hair, the composition comprising acombination of two or more thereof. In some embodiments, preventing breakage of the hair comprises reducing protein degradation. In some embodiments, reducing protein degradation comprises reducing oxidation of tryptophan or tyrosine residues in a hair protein of the hair as compared to oxidation of tryptophan or tyrosine residues in the hair protein of hair not applied with the composition. In some embodiments, protein degradation comprises breaking amide bonds of the hair protein. In some embodiments, reducing protein degradation comprises reducing amide bond breakage in hair applied with the composition as compared to hair not applied with the composition.

[0010] In some aspects, provided herein are methods of maintaining strength of hair, the method comprising: applying a composition to the hair, the composition comprising aWSGR Docket No. 63230-733.601combination of two or more thereof.

[0011] In some aspects, provided herein are methods of reducing fragility of hair, the method comprising: applying a composition to the hair, the composition comprising acombination of two or more thereof, wherein the fragility of the hair is reduced as compared to a fragility of hair not applied with the composition. In some embodiments, reducing fragility of hair comprises reducing protein degradation. In some embodiments, protein degradation comprises oxidation of tryptophan or tyrosine residues in a hair protein of the hair as compared to oxidation of tryptophan or tyrosine residues in the hair protein of hair not applied with the composition. In some embodiments, protein degradation comprises breaking of amide bonds of the hair protein. In some instances, breaking of amide bonds of the hair protein is determined with FTIR spectroscopy, Raman spectroscopy, or both. In some embodiments, the fragility of the hair is determined by measuring mechanical property of the hair. In some embodiments, the mechanical property comprises fragility, elasticity, or strength, or a combination thereof. In some embodiments, the elasticity is determined by measuring a Young’s Modulus of hair. In some embodiments, the Young’s Modulus of hair applied with the composition is at least about 3,000 Pa, about 3,200 Pa, about 3,400 Pa, about 3,600 Pa, about 3,800 Pa, about 4,000, about 4,200, about 4,400, about 4,600, about 4,800,WSGR Docket No. 63230-733.601about 5,000, about 5,200, about 5,400, about 5,600, about 5,800, about 6,000, about 6,200, about 6,400, about 6,600, about 6,800, or about 7,000. In some embodiments, the Young’s Modulus of hair applied with the composition has a Young’s Modulus about 2-fold, about 3-fold, about 4-fold, or about 5 -fold higher than a Young’s Modulus of hair not applied with the composition.

[0012] In some embodiments, the strength is determined by measuring a break stress of hair. In some embodiments, the break stress of hair applied with the composition is about 200 Pa to about 500 Pa. In some embodiments, the break stress of hair applied with the composition has a break stress about 2-fold, about 3-fold, about 4-fold, or about 5 -fold higher than a break stress of hair not applied with the composition.

[0013] In some aspects, provided herein are methods of shielding a hair of a subject from ultraviolet (UV) light, the method comprising: applying a composition to the hair of the subject, the composition comprising a compound having the structure: HOwherein the compound absorbs UV light having a wavelength of about 280 nm to about 400 nm. In some embodiments, the shielding is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electronWSGR Docket No. 63230-733.601microscopy (SEM), reflectance spectroscopy, UV absorbance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0014] In some aspects, provided herein are methods of preventing or minimizing penetration of UV light into a hair cortex of a subject, the method comprising: applying a composition to the hair, the composition comprising a compound having the structure:some embodiments, the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0015] In some aspects, provided herein are methods of preventing or minimizing formation of free radicals in a hair of a subject, the method comprising: applying a composition to the hair of the subject, the composition comprising a compound having thestructure:WSGR Docket No. 63230-733.601combination of two or more thereof. In some embodiments, the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0016] In some aspects, provided herein are methods of retaining the color of hair, the method comprising: applying a composition to the hair, the composition comprising acombination of two or more thereof, wherein at least about 60% of the hair color is retained in hair. In some embodiments, the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay.WSGR Docket No. 63230-733.601

[0017] In some aspects, provided herein are methods of coating a hair on a scalp of a subject, the method comprising: applying a composition to the hair on the scalp of thesubject, the composition comprising a compound having the structure:HO nH3..0, or a polymer thereof, or a combination of two or more thereof, wherein the composition is coated over a surface of the hair of the subject. In some embodiments, the coating is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, transepidermal water loss (TEWL) measurements, corneometry, or a combination thereof. In some embodiments, the composition is coated over about 5% to about 100% of the total surface of the hair on the scalp of the subject. In some embodiments, the composition is coated over at least about 10% of the total surface of the hair on the scalp of the subject. In some embodiments, the composition is coated over the total surface of the hair on the scalp of the subject. In some embodiments, the composition is coated over about 10% to about 95% of the total surface of the hair on the scalp of the subject. In some embodiments, the composition is heterogeneously coated over the surface of the hair on the scalp of the subject. In some embodiments, the composition is uniformly coated over the surface of the hair on the scalp of the subject. In some embodiments, applying the composition to the hair comprises coveringWSGR Docket No. 63230-733.601at least about 10% to about 100% of the total surface area of the hair. In some embodiments, applying the composition to the hair comprises covering at least about 10% to about 100% of a target surface area of the hair, wherein the target surface area of the hair is the surface area of the hair on the crown of a head. In some embodiments, after applying the composition to the hair, about 1% to about 20% of UV light is permitted into the cortex of the hair.

[0018] In some aspects, provided herein are methods of protecting skin comprising scalp of a subject from damage by ultraviolet (UV) light, the method comprising: applying a composition to the scalp the subject, the composition comprising a compound having thecombination of two or more thereof. In some embodiments, the damage is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0019] In some aspects, provided herein are methods of shielding a skin comprising a scalp of a subject from ultraviolet (UV) light, the method comprising: applying a composition to the scalp of the subject, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601, or a polymer thereof, or a combination of two or more thereof, wherein the compound absorbs UV light having a wavelength of about 280 nm to about 400 nm. In some embodiments, the shielding is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL measurements, corneometry, or a combination thereof.

[0020] In some aspects, provided herein are methods of preventing or minimizing penetration of UV light into a skin comprising scalp of a subject, the method comprising: applying a composition to the scalp, the composition comprising a compound having the N ^-Nstructure: HO noKNHor a polymer thereof, or a combination of two or more thereof. In some embodiments, the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL measurements, corneometry, or a combination thereof.

[0021] In some aspects, provided herein are methods of preventing or minimizing formation of free radicals in a skin comprising a scalp of a subject, the method comprising:WSGR Docket No. 63230-733.601applying a composition to the scalp of the subject, the composition comprising a compoundcombination of two or more thereof. In some embodiments, the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL measurements, corneometry, or a combination thereof.

[0022] In some aspects, provided herein are methods of coating a scalp of a subject, the method comprising: applying a composition to the scalp of the subject, the compositioncomprising a compound having the structure: T, HO" xxx? OH,thereof, or a combination of two or more thereof, wherein the composition is coated over a surface of the scalp of the subject. In some embodiments, the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM),WSGR Docket No. 63230-733.601reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL measurements, corneometry, or a combination thereof. In some embodiments, the composition is coated over about 5% to about 100% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over at least about 10% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over the total surface of the scalp of the subject. In some embodiments, the composition is coated over about 10% to about 95% of the total surface of the scalp of the subject. In some embodiments, the composition is heterogeneously coated over the surface on the scalp of the subject. In some embodiments, the composition is uniformly coated over the surface on the scalp of the subject. In some embodiments, applying the composition to the scalp comprises covering at least about 10% to about 100% of the total surface area of the scalp. In some embodiments, applying the composition to the scalp comprises covering at least about 10% to about 100% of a target surface area of the scalp, wherein the target surface area of the scalp is the surface area of the scalp on the crown of a head. In some embodiments, after applying the composition to the scalp, about 1% to about 20% of UV light is permitted through the scalp.

[0023] In some aspects, the compound or polymer thereof absorbs light having a wavelength of about 320 nm to about 400 nm. In some embodiments, the compound or polymer thereof absorbs light having a wavelength of about 280 nm to about 320 nm. In some embodiments, the compound or polymer thereof absorbs light having a wavelength of about 280 nm to about 400 nm. In some embodiments, the compound or polymer thereof has a molar absorptivity of about 0 mM-1cm-1over a wavelength of about 400 to about 800 nm.

[0024] In some embodiments, the polymer of the compound is represented by the structure of Formula (I):or a salt thereof, wherein:is selected from:WSGR Docket No. 63230-733.601each R1is independently selected from hydrogen, Ci-6 alkyl, -C(O)R23, and - C(O)OR23;each R2is independently selected from hydrogen, halogen, Ci-6 alkyl, -Si(R20)3, and - B(R21)2;each R3is independently selected from hydrogen and Ci-6 alkyl;each R4is independently selected from hydrogen and Ci-6 alkyl;each R5and R6are independently selected from hydrogen, -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from halogen and Ci-io alkyl;R7is selected from hydrogen, halogen, Ci-6 alkyl, and -B(R21)2;each R20is independently selected from Ci-6 alkyl;each R21is independently selected from -OR22;each R22is independently selected from hydrogen and Ci-6 alkyl; ortwo R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl;each R23is independently selected from Ci-6 alkyl which is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, - NH2, -N(CI-6 alkyl)2, Ci-6 alkyl, -Ci-ehaloalkyl, and -O-Ci-6 alkyl; and m is selected from 1 to 20.WSGR Docket No. 63230-733.601In some embodiments,. In some embodiments, each R1is independently selected from hydrogen, -C(O)R23, and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen. In some embodiments, each R2is independently selected from hydrogen, Ci-6 alkyl, -Si(R20)3, and -B(R21)2. In some embodiments, each R2is independently selected from hydrogen, -Si(R20)3, and -B(R21)2. In some embodiments, each R2is independently selected from hydrogen, -Si(Me)3, and -Bpin. In some embodiments, each R3is independently selected from hydrogen and Ci-4 alkyl. In some embodiments, each R3is independently selected from hydrogen. In some embodiments, each R4is selected from hydrogen and Ci-4 alkyl. In some embodiments, each R4is selected from hydrogen. In some embodiments, R7is selected from hydrogen, halogen, and -B(R21)2. In some embodiments, R7is selected from hydrogen, bromo, iodo, and -B(R21)2. In some embodiments, R7is selected from hydrogen, iodo, -B(R21)2. In some embodiments, each R5and R6are independently selected from -Si(R20)3 and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl. In some embodiments, each R5and R6are independently selected from -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally and independently substituted with one or more Ci-4 alkyl. In some embodiments, each R20is independently selected from Ci-4 alkyl. In some embodiments, each R22is independently selected from hydrogen; or two R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl. In some embodiments, two R22on different O atoms are taken together with the O atom toWSGR Docket No. 63230-733.601which each R22is attached to form a heterocycle, which is optionally substituted with one or more substituents independently selected from Ci-6 alkyl. In some embodiments, Formula (I) is represented by the structure of Formula (I-A):XRNr R,3Formula (I-A);or a salt thereof. In some embodiments, Formula (I) is represented by the structure ofR6°V / R7R5O- / X\, R1>== / ^N OR6R4R3J JrR1'N / ^R4Formula (I-B): R2R3Formula (I-B); or a salt thereof. In some embodiments, Formula (I) is represented by the structure of Formula (I-C):R6O R7. OR5R- Formula (I-C); or a salt thereof, wherein: m is selected from 1 to 20. In some embodiments, the compound is selected from:WSGR Docket No. 63230-733.601WSGR Docket No. 63230-733.601or a salt of any one thereof. In some embodiments, each R1is independently selected from hydrogen, -C(O)R23, and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen. In some embodiments, each R2is independently selected from hydrogen, Ci-6 alkyl, -Si(R20)3, and -B(R21)2. In some embodiments, each R2is independently selected from hydrogen, -Si(R20)3, and -B(R21)2. In some embodiments, each R2is independently selected from hydrogen, -Si(Me)3, and -Bpin. In some embodiments, each R3is independently selected from hydrogen and C1-4 alkyl. In some embodiments, each R3is independently selected from hydrogen. In some embodiments, each R4is selected from hydrogen and C1-4 alkyl. In some embodiments, each R4is selected from hydrogen. In some embodiments, R7is selected from hydrogen, halogen, and -B(R21)2. In some embodiments, R7is selected from hydrogen, bromo, iodo, and -B(R21)2. In some embodiments, R7is selected from hydrogen, iodo, -B(R21)2. In some embodiments, each R5and R6are independently selected from -Si(R20)3 and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl. In some embodiments, each R5and R6are independently selected from -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally and independently substituted with one or more C1-4 alkyl. In some embodiments, each R20is independently selected from C1-4 alkyl. In some embodiments, each R22is independently selected from hydrogen; or two R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from C1-10 alkyl.WSGR Docket No. 63230-733.601In some embodiments, two R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle, which is optionally substituted with one or more substituents independently selected from Ci-6 alkyl.DETAILED DESCRIPTION

[0025] Hair is susceptible to damage from the sun. Scalp is similarly susceptible to sun damage, which may result in development of hyperpigmentation or possibly melanomas. Deposits of hyperpigmentation on the scalp may arise from the accumulation of melanin, synthesized in the body from tyrosine, which aggregate and form eumelanin. Eumelanin is the source of the dark color contributing to pigmentation and hyperpigmentation of the skin. Melanin is also naturally found in hair and gives rise to the dark color of hair.

[0026] Current UV protectants (or sunscreens) come in two forms: absorptive and physical. Most absorptive sunscreens are synthetic molecules that are able to absorb UVA and / or UVB rays. However, these absorptive sunscreens have been controversial as some studies have found a correlation between these absorptive sunscreens, bodily uptake, and potentially cancer. Physical sunscreens are made of mineral particles that generally leave a white color on a surface, which can detract from a subject’s confidence and self-image. As such, there is a need for a biocompatible and safe sunscreen for hair and / or skin, such as scalp. Further, there is a need for a sunscreen that does not detract from a subject’s confidence and self-image.

[0027] Provided herein are methods for protecting hair and protecting scalp by applying compounds and polymers thereof, such as melanin and tyrosine derivatives. Melanin and tyrosine derivatives are advantageous because they are biocompatible, as they are derived from the naturally occurring melanin and tyrosine. Further, the compounds and polymers thereof described herein for use in hair and / or skin are able to absorb UVA, UVB, or both, while being substantially colorless. In other words, the compounds described herein advantageously and selectively absorb UVA, UVB, or both and do not absorb significantly in the visible region (roughly wavelengths of about 450 nm to about 800 nm). As such, the compounds described herein may be applied to hair and / or skin, such as scalp, of a subject as a UV protectant without changing hair color, which may negatively impact the subject’s confidence and self-image.Certain DefinitionsWSGR Docket No. 63230-733.601

[0028] Unless otherwise stated, the following terms used in this application have the definitions given below. The use of the term “including” as well as other forms, such as “include,” “includes,” and “included,” is not limiting. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0029] As used herein, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a sample” includes a plurality of samples, including mixtures thereof.

[0030] As used herein, the terms “determining,” “measuring,” “evaluating,” “assessing,” “assaying,” and “analyzing” are often used interchangeably herein to refer to forms of measurement. The terms include determining if an element is present or not (for example, detection). These terms can include quantitative, qualitative or both quantitative and qualitative determinations. The term “assessing” can be relative or absolute. “Detecting the presence of’ can include determining the amount of something present in addition to determining whether it is present or absent depending on the context.

[0031] As used herein, Ci-Cx and Ci-x are equivalent. Ci-Cx includes C1-C2, C1-C3... Ci-Cx; and Ci-x includes C1-2, C1-3... Ci-x. By way of example only, a group designated as " Ci-C4" indicates that there are one to four carbon atoms in the moiety, i.e., groups containing 1 carbon atom, 2 carbon atoms, 3 carbon atoms or 4 carbon atoms. Thus, by way of example only, " C1-C4 alkyl" indicates that there are one to four carbon atoms in the alkyl group, i.e., the alkyl group is selected from among methyl, ethyl, propyl, / .so-propyl. w-butyl, iso-butyl, sec-butyl, and / -butyl.

[0032] An “alkyl” group refers to a saturated aliphatic hydrocarbon group. The alkyl group is branched or straight chain. In some embodiments, the “alkyl” group has 1 to 10 carbon atoms, i.e., a Ci-Cioalkyl. Whenever it appears herein, a numerical range such as “1 to 10” refers to each integer in the given range; e.g., “1 to 10 carbon atoms” means that the alkyl group consist of 1 carbon atom, 2 carbon atoms, 3 carbon atoms, 4 carbon atoms, 5 carbon atoms, 6 carbon atoms, etc., up to and including 10 carbon atoms, although the present definition also covers the occurrence of the term “alkyl” where no numerical range is designated. In some embodiments, an alkyl is a Ci-Cealkyl. In one aspect the alkyl is methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, or t-butyl. Typical alkyl groups include, but are in no way limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secbutyl, tertiary butyl, pentyl, neopentyl, or hexyl.WSGR Docket No. 63230-733.601

[0033] An “alkylene” group refers to a divalent alkyl radical. Any of the above-mentioned monovalent alkyl groups may be an alkylene by abstraction of a second hydrogen atom from the alkyl. In some embodiments, an alkylene is a C1-C6alkylene. In other embodiments, an alkylene is a C1-C4alkylene. In certain embodiments, an alkylene comprises one to four carbon atoms (e.g., C1-C4 alkylene). In other embodiments, an alkylene comprises one to three carbon atoms (e.g., C1-C3 alkylene). In other embodiments, an alkylene comprises one to two carbon atoms (e.g., C1-C2 alkylene). In other embodiments, an alkylene comprises one carbon atom (e.g., Ci alkylene). In other embodiments, an alkylene comprises two carbon atoms (e.g., C2 alkylene). In other embodiments, an alkylene comprises two to four carbon atoms (e.g., C2-C4 alkylene). Typical alkylene groups include, but are not limited to, -CH2-, -CH(CH3)-, -C(CH3)2-, -CH2CH2-, -CH2CH(CH3)-, -CH2C(CH3)2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, and the like.

[0034] The term “alkenyl” refers to a type of alkyl group in which at least one carboncarbon double bond is present. In one embodiment, an alkenyl group has the formula -C(R)=CR.2, wherein R refers to the remaining portions of the alkenyl group, which may be the same or different. In some embodiments, R is H or an alkyl. In some embodiments, an alkenyl is selected from ethenyl (i.e., vinyl), propenyl (i.e., allyl), butenyl, pentenyl, pentadienyl, and the like. Non-limiting examples of an alkenyl group include -CH=CH2, -C(CH3)=CH2, -CH=CHCH3, -C(CH3)=CHCH3, and -CH2CH=CH2.

[0035] The term “alkynyl” refers to a type of alkyl group in which at least one carboncarbon triple bond is present. In one embodiment, an alkenyl group has the formula -C=C-R, wherein R refers to the remaining portions of the alkynyl group. In some embodiments, R is H or an alkyl. In some embodiments, an alkynyl is selected from ethynyl, propynyl, butynyl, pentynyl, hexynyl, and the like. Non-limiting examples of an alkynyl group include -C≡CH, -C≡CCH3-C≡CCH2CH3, -CH2C≡CH.

[0036] An “alkoxy” group refers to a (alkyl)O- group, where alkyl is as defined herein.

[0037] The term “alkylamine” refers to the -N(alkyl)xHygroup, where x is 0 and y is 2, or where x is 1 and y is 1, or where x is 2 and y is 0.

[0038] The term “aromatic” refers to a planar ring having a delocalized -electron system containing 4n+2 π electrons, where n is an integer. The term “aromatic” includes both carbocyclic aryl (“aryl,” e.g., phenyl) and heterocyclic aryl (or “heteroaryl” or “heteroaromatic”) groups (e.g., pyridine). The term includes monocyclic or fused-ring polycyclic (i.e., rings which share adjacent pairs of carbon atoms) groups.WSGR Docket No. 63230-733.601

[0039] The term “carbocyclic” or “carbocycle” refers to a ring or ring system where the atoms forming the backbone of the ring are all carbon atoms. The term thus distinguishes carbocyclic from “heterocyclic” rings or “heterocycles” in which the ring backbone contains at least one atom that is different from carbon. In some embodiments, carbocycles are monocyclic, bicyclic, multicyclic, spirocyclic or bridged rings. In some embodiments, a carbocycle is a monocyclic carbocycle or a bicyclic carbocycle. In some embodiments, at least one of the two rings of a bicyclic carbocycle is aromatic. In some embodiments, one of the two rings of a bicyclic carbocycle is aromatic, and the point of attachment to the remaining of the compound is at a carbon atom of the aromatic ring. In some embodiments, one of the two rings of a bicyclic carbocycle is aromatic, and the point of attachment to the remaining of the compound is at a carbon atom of the non-aromatic ring. In some embodiments, bicyclic carbocycle is a fused bicyclic carbocycle. In some embodiments, both rings of a fused bicyclic carbocycle are aromatic (i.e., an aryl). Carbocycle includes cycloalkyl and aryl.

[0040] The term “bicyclic carbocyclic” refers to two carbocycles that are fused together and share two adjacent carbon atoms.

[0041] As used herein, the term “aryl” refers to an aromatic ring wherein each of the atoms forming the ring is a carbon atom. In one aspect, aryl is phenyl, naphthyl, or biphenyl. In some embodiments, an aryl is a phenyl. In some embodiments, aryl is biphenyl. In some embodiments, an aryl is a C6-C12aryl. In some embodiments, an aryl is a C6-C10aryl.Depending on the structure, an aryl group is a monoradical or a diradical (i.e., an arylene group).

[0042] The term “cycloalkyl” refers to a stable, partially or fully saturated, monocyclic or polycyclic carbocyclic ring, which may include fused (when fused with an aryl or a heteroaryl ring, the cycloalkyl is bonded through a non-aromatic ring atom) or bridged ring systems. Representative cycloalkyls include, but are not limited to, cycloalkyls having from three to fifteen carbon atoms (C3-C15 cycloalkyl), from three to ten carbon atoms (C3-C10 cycloalkyl), from three to eight carbon atoms (C3-C8 cycloalkyl), from three to six carbon atoms (C3-C6 cycloalkyl), from three to five carbon atoms (C3-C5 cycloalkyl), or three to four carbon atoms (C3-C4 cycloalkyl). In some embodiments, the cycloalkyl is a 3- to 6-membered cycloalkyl. In some embodiments, the cycloalkyl is a 5- to 6-membered cycloalkyl.

[0043] The term “monocyclic cycloalkyl” refers to cyclic saturated aliphatic hydrocarbon that has one ring. Monocyclic cycloalkyls include from 3 to 10 carbon atoms in the ring (i.e., a monocyclic Ci-Ciocycloalkyl). Monocyclic cycloalkyls that include 3 to 10 carbon atoms inWSGR Docket No. 63230-733.601the ring include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononane, and cyclodecane. In some embodiments, a monocyclic cycloalkyl is a monocyclic C3-C6cycloalkyl. Monocyclic C3-C6cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0044] The term “cycloalkenyl” refers to a type of non-aromatic cycloalkyl group in which at least one carbon-carbon double bond is present. In some embodiments, cycloalkenyl is a monocyclic cycloalkenyl.

[0045] In some embodiments, monocyclic cycloalkenyl has 5 to 12 carbon atoms (i.e., a C5-C12cycloalkenyl). In some embodiments, monocyclic cycloalkenyl has 5 to 8 carbon atoms (i.e., a C5-C12cycloalkenyl). Non-limiting examples of cycloalkenyls include:o o O O O O O O O. Q

[0046] The term “halo” or, alternatively, “halogen” or “halide” means fluoro, chloro, bromo, or iodo. In some embodiments, halo is F, Cl, Br, or I. In some embodiments, halo is fluoro, chloro, or bromo. In some embodiments, halo is F, Cl, or Br.

[0047] The term “haloalkyl” refers to an alkyl in which one or more hydrogen atoms are replaced by a halogen atom. In one aspect, a haloalkyl is a Ci-Cefluoroalkyl, Ci-Cechloroalkyl, or Ci-Cebromoalkyl. In some cases, a haloalkyl is a Ci-Cefluoroalkyl.

[0048] The term “fluoroalkyl” refers to an alkyl in which one or more hydrogen atoms are replaced by a fluorine atom. In one aspect, a fluoroalkyl is a Ci-Cefluoroalkyl. In some embodiments, a fluoroalkyl is selected from trifluoromethyl, difluoromethyl, fluoromethyl, 2,2,2-trifluoroethyl, 1 -fluoromethyl -2 -fluoroethyl, and the like. In some cases, a fluoroalkyl is selected from trifluoromethyl, difluoromethyl, and fluoromethyl.

[0049] The term “heteroalkyl” refers to an alkyl group in which one or more skeletal atoms of the alkyl are selected from an atom other than carbon, e.g., oxygen, nitrogen (e.g. -NH-, -N(alkyl)-, sulfur, or combinations thereof. A heteroalkyl is attached to the rest of the molecule at a carbon atom of the heteroalkyl. In one aspect, a heteroalkyl is a Ci- OHCeheteroalkyl. In some cases, a Ci-Ceheteroalkyl is

[0050] The term “heterocycle” or “heterocyclic” refers to heteroaromatic rings (also known as heteroaryls) and heterocycloalkyl rings containing one to four heteroatoms in theWSGR Docket No. 63230-733.601ring(s), where each heteroatom in the ring(s) is selected from O, S and N, wherein each heterocyclic group has from 3 to 10 atoms in its ring system, and with the proviso that any ring does not contain two adjacent O or S atoms. Non-aromatic heterocyclic groups (also known as heterocycloalkyls) include rings having 3 to 10 atoms in its ring system and aromatic heterocyclic groups include rings having 5 to 10 atoms in its ring system. The heterocyclic groups include benzo-fused ring systems. Examples of non-aromatic heterocyclic groups are pyrrolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothienyl, oxazolidinonyl, tetrahydropyranyl, dihydropyranyl, tetrahydrothiopyranyl, piperidinyl, morpholinyl, thiomorpholinyl, thioxanyl, piperazinyl, aziridinyl, azetidinyl, oxetanyl, thietanyl, homopiperidinyl, oxepanyl, thiepanyl, oxazepinyl, diazepinyl, thiazepinyl, 1, 2,3,6-tetrahydropyridinyl, pyrrolin-2-yl, pyrrolin-3-yl, indolinyl, 2H-pyranyl, 4H-pyranyl, dioxanyl, 1,3-dioxolanyl, pyrazolinyl, dithianyl, dithiolanyl, dihydropyranyl, dihydrothienyl, dihydrofuranyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, 3-azabicyclo[3.1.0]hexanyl, 3-azabicyclo[4.1.0]heptanyl, 3H-indolyl, indolin-2-onyl, isoindolin-l-onyl, isoindoline- 1,3-dionyl, 3,4-dihydroisoquinolin-l(2H)-onyl, 3,4-dihydroquinolin-2(lH)-onyl, isoindoline- 1,3-dithionyl, benzo [d]oxazol-2(3H)-onyl, lH-benzo[d]imidazol-2(3H)-onyl, benzo [d]thiazol-2(3H)-onyl, and quinolizinyl. Examples of aromatic heterocyclic groups are pyridinyl, imidazolyl, pyrimidinyl, pyrazolyl, triazolyl, pyrazinyl, tetrazolyl, furyl, thienyl, isoxazolyl, thiazolyl, oxazolyl, isothiazolyl, pyrrolyl, quinolinyl, isoquinolinyl, indolyl, benzimidazolyl, benzofuranyl, cinnolinyl, indazolyl, indolizinyl, phthalazinyl, pyridazinyl, triazinyl, isoindolyl, pteridinyl, purinyl, oxadiazolyl, thiadiazolyl, furazanyl, benzofurazanyl, benzothiophenyl, benzothiazolyl, benzoxazolyl, quinazolinyl, quinoxalinyl, naphthyridinyl, and furopyridinyl. The foregoing groups are either C-attached (or C-linked) or -attached where such is possible. For instance, a group derived from pyrrole includes both pyrrol-1-yl (-attached) or pyrrol-3-yl (C-attached). Further, a group derived from imidazole includes imidazol-1-yl or imidazol-3-yl (both -attached) or imidazol-2-yl, imidazol-4-yl or imidazol-5-yl (all C-attached). The heterocyclic groups include benzo-fused ring systems. Non-aromatic heterocycles are optionally substituted with one or two oxo (=0) moieties, such as pyrrolidin-2-one. In some embodiments, at least one of the two rings of a bicyclic heterocycle is aromatic. In some embodiments, both rings of a bicyclic heterocycle are aromatic.

[0051] The terms “heteroaryl” or, alternatively, “heteroaromatic” refers to an aryl group that includes one or more ring heteroatoms selected from nitrogen, oxygen, and sulfur.Illustrative examples of heteroaryl groups include monocyclic heteroaryls and bicyclic heteroaryls. Monocyclic heteroaryls include pyridinyl, imidazolyl, pyrimidinyl, pyrazolyl,WSGR Docket No. 63230-733.601triazolyl, pyrazinyl, tetrazolyl, furyl, thienyl, isoxazolyl, thiazolyl, oxazolyl, isothiazolyl, pyrrolyl, pyridazinyl, triazinyl, oxadiazolyl, thiadiazolyl, and furazanyl. Monocyclic heteroaryls include indolizine, indole, benzofuran, benzothiophene, indazole, benzimidazole, purine, quinolizine, quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline, 1,8-naphthyridine, and pteridine. In some embodiments, a heteroaryl contains 0-4 N atoms in the ring. In some embodiments, a heteroaryl contains 1-4 N atoms in the ring. In some embodiments, a heteroaryl contains 0-4 N atoms, 0-1 0 atoms, and 0-1 S atoms in the ring. In some embodiments, a heteroaryl contains 1-4 N atoms, 0-1 0 atoms, and 0-1 S atoms in the ring. In some embodiments, heteroaryl is a C1-C9heteroaryl. In some embodiments, monocyclic heteroaryl is a C1-C5heteroaryl. In some embodiments, monocyclic heteroaryl is a 5 -membered or 6-membered heteroaryl. In some embodiments, bicyclic heteroaryl is a C6-C9heteroaryl.

[0052] A “heterocycloalkyl” group refers to a cycloalkyl group that includes at least one heteroatom selected from nitrogen, oxygen and sulfur. In some embodiments, a heterocycloalkyl is fused with an aryl or heteroaryl. In some embodiments, the heterocycloalkyl is oxazolidinonyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydrothienyl, tetrahydropyranyl, tetrahydrothiopyranyl, piperidinyl, morpholinyl, thiomorpholinyl, piperazinyl, piperidin-2-onyl, pyrrolidine-2, 5-dithionyl, pyrrolidine-2,5 -dionyl, pyrrolidinonyl, imidazolidinyl, imidazolidin-2-onyl, or thiazolidin-2-onyl. In one aspect, a heterocycloalkyl is a C2-Cioheterocycloalkyl. In another aspect, a heterocycloalkyl is a Cr-Cioheterocycloalkyl. In some embodiments, a heterocycloalkyl is monocyclic or bicyclic. In some embodiments, a heterocycloalkyl is monocyclic and is a 3, 4, 5, 6, 7, or 8-membered ring. In some embodiments, a heterocycloalkyl is monocyclic and is a 3, 4, 5, or 6-membered ring. In some embodiments, a heterocycloalkyl is monocyclic and is a 3 or 4-membered ring. In some embodiments, a heterocycloalkyl contains 0-2 N atoms in the ring. In some embodiments, a heterocycloalkyl contains 0-2 N atoms, 0-2 O atoms and 0-1 S atoms in the ring.

[0053] The term “bond” or “single bond” refers to a chemical bond between two atoms, or two moieties when the atoms joined by the bond are considered to be part of larger substructure. In one aspect, when a group described herein is a bond, the referenced group is absent thereby allowing a bond to be formed between the remaining identified groups.

[0054] The term “moiety” refers to a specific segment or functional group of a molecule. Chemical moieties are often recognized chemical entities embedded in or appended to a molecule.WSGR Docket No. 63230-733.601

[0055] The term “oligomer” refers to a compound consisting of repeating subunits. In some embodiments, the repeating subunits are of the same molecular structure. In some cases, the repeating subunits have different molecular structure. By way of example only, anoligomer is a compound represented by the structure selected from: H-S-S— S-y H-S-E— E-y H- -E— E-y H-E— E— E^lH-a-E— s— E— E— EfH, andHL-E E E —Jn |, w,herei. FAn — B Cand LPJ represent different subunits; each n is independently selected from 1 to 20; and the wiggle line ’ denotes a point of attachment to another subunit L D, or. Depending on the structure of the subunit, the subunit is a monoradical), a diradical (), or a tetraradical ( — L~ ). In some cases, oligomer comprise a linear structure. In some cases, an oligomer comprises a branched structure.

[0056] The term “optionally substituted” or “substituted” means that the referenced group is optionally substituted with one or more additional group(s) individually and independently selected from D, halogen, -CN, -NH2, -NH(alkyl), -N(alkyl)2, -OH, -CO2H, -CO2alkyl, -C(=O)NH2, -C(=O)NH(alkyl), -C(=O)N(alkyl)2, -S(=O)2NH2, -S(=O)2NH(alkyl), -S(=O)2N(alkyl)2, alkyl, cycloalkyl, fluoroalkyl, heteroalkyl, alkoxy, fluoroalkoxy, heterocycloalkyl, aryl, heteroaryl, aryloxy, alkylthio, arylthio, alkylsulfoxide, arylsulfoxide, alkylsulfone, and arylsulfone. In some other embodiments, optional substituents are independently selected from D, halogen, -CN, -NH2, -NH(CH3), -N(CH3)2, -OH, -CO2H, -CO2(Ci-C4alkyl), -C(=O)NH2, -C(=O)NH(Ci-C4alkyl), -C(=O)N(Ci-C4alkyl)2, -S(=O)2NH2, -S(=O)2NH(Ci-C4alkyl), -S(=O)2N(C1-C4alkyl)2, Ci-C4alkyl, C3-C6cycloalkyl, Ci-C4fluoroalkyl, Ci-C4heteroalkyl, Ci-C4alkoxy, Ci-C4fluoroalkoxy, -SCi-C4alkyl, -S(=O)Ci-C4alkyl, and -S(=O)2Ci-C4alkyl. In some embodiments, optional substituents are independently selected from D, halogen, -CN, -NH2, -OH, -NH(CH3), -N(CH3)2, -CH3, -CH2CH3, -CF3, -OCH3, and -OCF3. In some embodiments, substituted groups are substituted with one or two of the preceding groups. In some embodiments, an optional substituent on an aliphatic carbon atom (acyclic or cyclic) includes oxo (=0).WSGR Docket No. 63230-733.601

[0057] The term “substantially” as used herein in reference to a given parameter, property, or condition means and includes to a degree that one of ordinary skill in the art would understand that the given parameter, property, or condition is met with a degree of variance, such as within acceptable manufacturing tolerances. By way of example, depending on the particular parameter, property, or condition that is substantially met, the parameter, property, or condition may be at least 90.0% met, at least 95.0% met, at least 99.0% met, or even at least 99.9% met.

[0058] As used herein, the term “about” or “approximately” when referring to a measurable value such as an amount or concentration and the like, is meant to encompass variations of 20%, 10%, 5%, 1%, 0.5%, or 0.1% of the specified amount. In some instances, the term “about” includes the value itself. For example, “about” can mean plus or minus 10%, per the practice in the art. Alternatively, “about” can mean a range of plus or minus (±) 20%, plus or minus 10%, plus or minus 5%, or plus or minus 1% of a given value. Alternatively, particularly with respect processes, the term can mean within an order of magnitude, up to 5-fold, or up to 2-fold, of a value. Where particular values can be described in the application and claims, unless otherwise stated the term “about” may be assumed to encompass the acceptable error range for the particular value and the particular value itself. Also, where ranges, subranges, or both, of values can be provided, the ranges or subranges can include the endpoints of the ranges or subranges. Where values are described as ranges, it may be understood that such disclosure includes the disclosure of all possible sub-ranges within such ranges, as well as specific numerical values that fall within such ranges irrespective of whether a specific numerical value or specific sub-range is expressly stated.

[0059] The terms “covering” and “coating” are used interchangeably.

[0060] The term “skin” includes scalp and skin on other areas of a subject’s body.

[0061] The term “scalp” may be used interchangeably with “skin”, and the methods and compositions applied to scalp may be applied to skin generally (e.g., skin on arms, legs, trunk, stomach, and the like of a subject).

[0062] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.Methods for Hair

[0063] In some respects, provided herein are methods for protecting hair of a subject from damage by ultraviolet (UV) light. In some embodiments, the method comprises applying a composition to the hair the subject, the composition comprising a compound having theWSGR Docket No. 63230-733.601of two or more thereof. In some embodiments, the compound of the composition has thestructure(Compound 1). In some embodiments, the compound of theH HO^^X^N,0composition has the structure HO x H OH (Compound 2). In some embodiments,the compound of the composition has the structure(Compound 3). In someembodiments, the compound of the composition has the structure(Compound 4). In some embodiments, the compound of the composition has the structure(Compound 5).WSGR Docket No. 63230-733.601

[0064] In some embodiments, the damage to hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof. In some embodiments, the damage to hair treated with the compound is reduced by about 1%, about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 97%, or about 100% as compared to hair that is not treated with the compound.

[0065] In some embodiments, hair treated with the compound of the instant disclosure exhibits has an improved denaturation temperature (Taor Td) of about 1%, about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 97%, or about 100% as compared to hair that is not treated with the compound of the instant disclosure. In some embodiments, the improvement in the denaturation temperature is determined by DSC. In some embodiments, the denaturation temperature of hair treated with the composition and exposed to UV light is about the same as a denaturation temperature of a control sample comprising hair that is not treated with the composition and not exposed to UV light.

[0066] In some aspects, provided herein are methods for preventing discoloration of hair of a subject. In some embodiments, the method comprises applying a composition to the hair the HOsubject, the composition comprising a compound having the structure:HOWSGR Docket No. 63230-733.601, or a polymer thereof, or a combination of two or more thereof. InHOpolymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof. In some embodiments, the compound of the HNcomposition has the structureor a polymer thereof. In some embodiments,O^OO Othe compound of the composition has the structureor a polymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof.

[0067] In some embodiments, the damage to hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanningWSGR Docket No. 63230-733.601electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0068] In some aspects, provided herein are methods for preventing discoloration of hair of a subject. In some embodiments, the method comprises applying a composition to the hair theHsome embodiments, the compound of the composition has the structureHOOr a polymer thereof. In some embodiments, the compound of the composition has the structureHHO OH or a polymer thereof. In some embodiments, the compound of the H0-^^X^Ncomposition has the structure x0 I X / D""7or apolymer thereof. In some embodiments,WSGR Docket No. 63230-733.601the compound of the composition has the structure' ' or; polymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof.

[0069] In some embodiments, the damage to hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay, and wherein the hair has been applied with the composition. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 50. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 45. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 40. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 35. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 30. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 25. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 20. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 15. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 10. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 9. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 8. In someWSGR Docket No. 63230-733.601embodiments, the hair exhibits a hair color loss (ΔE) of less than about 7. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 6. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 5. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 4. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 3. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 2. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 1. In some embodiments, the hair exhibits a hair color loss (ΔE) of about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay. In some embodiments, the hair exhibits a ΔE of about 1 to about 50, about 1 to about 45, about 1 to about 40, about 1 to about 35, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 9, about 1 to about 8, about 1 to about 7, about 1 to about 6, about 1 to about 5, about 1 to about 4, about 1 to about 3, about 1 to about 2, about 2 to about 50, about 2 to about 45, about 2 to about 40, about 2 to about 35, about 2 to about 30, about 2 to about 25, about 2 to about 20, about 2 to about 15, about 2 to about 10, about 2 to about 9, about 2 to about 8, about 2 to about 7, about 2 to about 6, about 2 to about 5, about 2 to about 4, about 2 to about 3, about 3 to about 50, about 3 to about 45, about 3 to about 40, about 3 to about 35, about 3 to about 30, about 3 to about 25, about 3 to about 20, about 3 to about 15, about 3 to about 10, about 3 to about 9, about 3 to about 8, about 3 to about 7, about 3 to about 6, about 3 to about 5, about 3 to about 4, about 4 to about 50, about 4 to about 45, about 4 to about 40, about 4 to about 35, about 4 to about 30, about 4 to about 25, about 4 to about 20, about 4 to about 15, about 4 to about 10, about 4 to about 9, about 4 to about 8, about 4 to about 7, about 4 to about 6, about 4 to about 5, about 5 to about 50, about 5 to about 45, about 5 to about 40, about 5 to about 35, about 5 to about 30, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 5 to about 9, about 5 to about 8, about 5 to about 7, about 5 to about 6, about 6 to about 50, about 6 to about 45, about 6 to about 40, about 6 to about 35, about 6 to about 30, about 6 to about 25, about 6 to about 20, about 6 to about 15, about 6 to about 10, about 6 to about 9, about 6 to about 8, about 6 to about 7, about 7 to about 50, about 7 to about 45, about 7 to about 40, about 7 to about 35, about 7 to about 30, about 7 to about 25, about 7 to about 20, about 7 to about 15, about 7 to about 10, about 7 to about 9, about 7 to about 8, about 8 to about 50, about 8 to about 45, about 8 to about 40, about 8 to about 35, about 8 to about 30, about 8 to about 25, about 8 to about 20, about 8 to about 15, about 8 to about 10,WSGR Docket No. 63230-733.601about 8 to about 9, about 9 to about 50, about 9 to about 45, about 9 to about 40, about 9 to about 35, about 9 to about 30, about 9 to about 25, about 9 to about 20, about 9 to about 15, about 9 to about 10, about 10 to about 50, about 10 to about 45, about 10 to about 40, or about 10 to about 35.

[0070] In some aspects, provided herein are methods for preventing loss of color from hair of a subject. In some embodiments, the method comprises applying a composition to the hair H HO-^X-N the subject, the composition comprising a compound having the structure:HO X'sX)Hsome embodiments, the compound of the composition has the structureHHnOXX?Or a polymer thereof. In some embodiments, the compound of the composition has the structure HO-^X^N OHO XXM OH or a polymer thereof. In some embodiments, the compound of thecomposition has the structureor a polymer thereof. In some embodiments,WSGR Docket No. 63230-733.601the compound of the composition has the structure' ' or; polymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof.

[0071] In some embodiments, the loss of color in hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay, and wherein the hair has been applied with the composition. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 10. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 9. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 8. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 7. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 6. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 5. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 4. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 3. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 2. In some embodiments, the hair exhibits a hair color loss (AE) of less than about 1. In some embodiments, the hair exhibits a hair color loss (AE) of about 1 to about 10, about 1 to about 9, about 1 to about 8, about 1 to about 7, about 1 to about 6, about 1 to about 5, about 1 toWSGR Docket No. 63230-733.601about 4, about 1 to about 3, about 1 to about 2, about 2 to about 10, about 2 to about 9, about 2 to about 8, about 2 to about 7, about 2 to about 6, about 2 to about 5, about 2 to about 4, about 2 to about 3, about 3 to about 10, about 3 to about 9, about 3 to about 8, about 3 to about 7, about 3 to about 6, about 3 to about 5, about 3 to about 4, about 4 to about 10, about 4 to about 9, about 4 to about 8, about 4 to about 7, about 4 to about 6, or about 4 to about 5.

[0072] In some aspects, provided herein are methods for preventing breakage of hair of a subject. In some embodiments, preventing breakage of the hair comprises reducing protein degradation of hair. In some embodiments, protein degradation comprises oxidation of tryptophan, tyrosine, or both, in hair. In some embodiments, oxidation of tryptophan or tyrosine residues in a hair protein as compared to oxidation of tryptophan or tyrosine residues in the hair protein not applied with the composition. In some embodiments, protein degradation comprises breaking amide bonds in a protein in hair. In some embodiments, reducing protein degradation comprises reducing breakage of amide bonds in the protein of hair. In some embodiments, the method comprises applying a composition to the hair the H HCkXxN subject, the composition comprising a compound having the structure:,Hsome embodiments, the compound of the composition has the structureYJO or aWSGR Docket No. 63230-733.601polymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof. In some embodiments, the compound of the HNcomposition has the structureor a polymer thereof. In some embodiments,O^Othe compound of the composition has the structureor a polymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof. In some embodiments, the protein in hair comprises type I keratin, type II keratin, or both.

[0073] In some embodiments, the loss of color in hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0074] In some aspects, provided herein are methods of maintaining strength of hair. In some embodiments, the method comprises applying a composition to the hair, theNcomposition comprising a compound having the structure:HOWSGR Docket No. 63230-733.601Hsome embodiments, the compound of the composition has the structureu.xx> or a polymer thereof. In some embodiments, the compound of the composition has the structure HOHO XJLH OH or a polymer thereof. In some embodiments, the compound of thecomposition has the structurethe compound of the composition has the structure or a polymerWSGR Docket No. 63230-733.601thereof. In some embodiments, the compound of the composition has the structure

[0075] In some aspects, provided herein are methods of reducing fragility of hair. In some embodiments, the method comprises applying a composition to the hair, the compositionthereof, or a combination of two or more thereof. In some embodiments, the fragility of the hair is reduced as compared to a fragility of hair not applied with the composition.

[0076] In some embodiments, reducing fragility of hair comprises reducing protein degradation of a protein in hair. In some embodiments, protein degradation comprises oxidation of tryptophan, tyrosine, or both. In some embodiments, protein degradation comprises breaking amide bonds in a hair protein. In some embodiments, reducing protein degradation comprises reducing oxidation of tryptophan or tyrosine residues in a hair protein of the hair as compared to oxidation of tryptophan or tyrosine residues in the hair protein of the hair not applied with the composition. In some embodiments, the hair protein comprises keratin, keratin-associated protein, or both. In some embodiments, the keratin comprises type I keratin, type II keratin, or both. In some embodiments, applying the composition to hair comprises reducing oxidation of about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 96%,WSGR Docket No. 63230-733.601about 96%, about 98%, about 99%, or about 100% the total concentration of tyrosine and tryptophan residues in hair. In some embodiments, applying the composition to hair comprises reducing oxidation of about 5% to about 100%, about 5% to about 90%, about 5% to about 80%, about 5% to about 70%, about 5% to about 60%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 5% to about 20%, about 5% to about 10%, about 10% to about 100%, about 10% to about 90%, about 10% to about 80%, about 10% to about 70%, about 10% to about 60%, about 10% to about 50%, about 10% to about 40%, about 10% to about 30%, about 10% to about 20%, about 15% to about 100%, about 15% to about 90%, about 15% to about 80%, about 15% to about 70%, about 15% to about 60%, about 15% to about 50%, about 15% to about 40%, about 15% to about 30%, about 15% to about 20%, about 20% to about 100%, about 20% to about 90%, about 20% to about 80%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, about 20% to about 40%, about 20% to about 30%, about 30% to about 100%, about 30% to about 90%, about 30% to about 80%, about 30% to about 70%, about 30% to about 60%, about 30% to about 50%, about 30% to about 40%, about 40% to about 100%, about 40% to about 90%, about 40% to about 80%, about 40% to about 70%, about 40% to about 60%, about 40% to about 50%, about 50% to about 100%, about 50% to about 90%, about 50% to about 80%, about 50% to about 70%, about 50% to about 60%, about 60% to about 100%, about 60% to about 90%, about 60% to about 80%, about 60% to about 70%, about 70% to about 100%, about 70% to about 90%, about 70% to about 80%, about 80% to about 100%, or about 80% to about 90%. In some embodiments, applying the composition to hair comprises reducing oxidation of at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, or about 95% of a total concentration of tyrosine and tryptophan residues in keratin in hair.

[0077] In some embodiments, the reduction of oxidation of the total concentration of tyrosine and tryptophan residues is determined by UV absorbance spectroscopy. In some embodiments, the absorbance of a total concentration of tyrosine and tryptophan residues is measured by UV absorbance spectroscopy at a wavelength of about 230 nm to about 300 nm. In some instances, the area under the curve (AUC) is determined over a range of wavelengths of about 230 nm to about 300 nm. In some instances, the AUC of hair to which the composition is not applied is determined as a reference (AUC0). In some instances, the AUC of hair applied with the composition is determined over a range of wavelengths of about 230 nm to about 300 nm. In some instances, the hair applied with the composition is washed toWSGR Docket No. 63230-733.601remove the composition prior to determining the AUC of the hair over about 230 nm to about 300 nm (AUCi). In some instances, the reduction of oxidation is determined by taking the difference of AUCo and AUCi.

[0078] In some embodiments, the strength of hair, integrity of hair, hair health, or a combination thereof, is determined by measuring a denaturation temperature (Ta or Td, expressed in degrees Celsius (°C)). In some embodiments, the Td of hair is about 145 °C to about 150 °C. In some embodiments, the Td of hair treated with the composition and UV radiation is about the same as the Td of hair untreated and not exposed to UV radiation. In some embodiments, the Td of hair treated with the composition is at least about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or about 100% the Td of hair untreated with the composition and not exposed to UV radiation. In some embodiments, the Td of hair treated with the composition is improved by about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or about 20% compared to hair that is untreated.

[0079] In some embodiments, the fragility of the hair is determined by measuring a Young’s Modulus of hair. In some embodiments, the Young’s Modulus of hair applied with the composition is at least about 3,000 Pa, about 3,200 Pa, about 3,400 Pa, about 3,600 Pa, about 3,800 Pa, about 4,000 Pa, about 4,200 Pa, about 4,400 Pa, about 4,600 Pa, about 4,800 Pa, about 5,000 Pa, about 5,200 Pa, about 5,400 Pa, about 5,600 Pa, about 5,800 Pa, about 6,000 Pa, about 6,200 Pa, about 6,400 Pa, about 6,600 Pa, about 6,800 Pa, about 7,000 Pa, or about 7,200 Pa. In some embodiments, the Young’s Modulus of hair applied with the composition is about 3,000 Pa to about 7,000 Pa, about 3,000 Pa to about 6,800 Pa, about 3,000 Pa to about 6,600 Pa, about 3,000 Pa to about 6,400 Pa, about 3,000 Pa to about 6,200 Pa, about 3,000 Pa to about 6,000 Pa, about 3,000 Pa to about 5,800 Pa, about 3,000 Pa to about 5,600 Pa, about 3,000 Pa to about 5,400 Pa, about 3,000 Pa to about 5,200 Pa, about 3,000 Pa to about 5,000 Pa, about 3,000 Pa to about 4,800 Pa, about 3,000 Pa to about 4,600 Pa, about 3,000 Pa to about 4,400 Pa, about 3,000 Pa to about 4,200 Pa, about 3,200 Pa to about 7,000 Pa, about 3,200 Pa to about 6,800 Pa, about 3,200 Pa to about 6,600 Pa, about 3,200 Pa to about 6,400 Pa, about 3,200 Pa to about 6,200 Pa, about 3,200 Pa to about 6,000 Pa, about 3,200 Pa to about 5,800 Pa, about 3,200 Pa to about 5,600 Pa, about 3,200 Pa to about 5,400 Pa, about 3,200 Pa to about 5,200 Pa, about 3,200 Pa to about 5,000 Pa, about 3,200 Pa to about 4,800 Pa, about 3,200 Pa to about 4,600 Pa, about 3,200 Pa to about 4,400 Pa, about 3,200 Pa to about 4,200 Pa, about 3,400 Pa to about 7,000 Pa, about 3,400 Pa to about 6,800 Pa, about 3,400 Pa to about 6,600 Pa, about 3,400 Pa to about 6,400 Pa, aboutWSGR Docket No. 63230-733.6013,400 Pa to about 6,200 Pa, about 3,400 Pa to about 6,000 Pa, about 3,400 Pa to about 5,800 Pa, about 3,400 Pa to about 5,600 Pa, about 3,400 Pa to about 5,400 Pa, about 3,400 Pa to about 5,200 Pa, about 3,400 Pa to about 5,000 Pa, about 3,400 Pa to about 4,800 Pa, about 3,400 Pa to about 4,600 Pa, about 3,400 Pa to about 4,400 Pa, about 3,400 Pa to about 4,200 Pa, about 3,600 Pa to about 7,000 Pa, about 3,600 Pa to about 6,800 Pa, about 3,600 Pa to about 6,600 Pa, about 3,600 Pa to about 6,400 Pa, about 3,600 Pa to about 6,200 Pa, about 3,600 Pa to about 6,000 Pa, about 3,600 Pa to about 5,800 Pa, about 3,600 Pa to about 5,600 Pa, about 3,600 Pa to about 5,400 Pa, about 3,600 Pa to about 5,200 Pa, about 3,600 Pa to about 5,000 Pa, about 3,600 Pa to about 4,800 Pa, about 3,600 Pa to about 4,600 Pa, about 3,600 Pa to about 4,400 Pa, about 3,600 Pa to about 4,200 Pa, about 3,800 Pa to about 7,000 Pa, about 3,800 Pa to about 6,800 Pa, about 3,800 Pa to about 6,600 Pa, about 3,800 Pa to about 6,400 Pa, about 3,800 Pa to about 6,200 Pa, about 3,800 Pa to about 6,000 Pa, about 3,800 Pa to about 5,800 Pa, about 3,800 Pa to about 5,600 Pa, about 3,800 Pa to about 5,400 Pa, about 3,800 Pa to about 5,200 Pa, about 3,800 Pa to about 5,000 Pa, about 3,800 Pa to about 4,800 Pa, about 3,800 Pa to about 4,600 Pa, about 3,800 Pa to about 4,400 Pa, about 3,800 Pa to about 4,200 Pa, about 4,000 Pa to about 7,000 Pa, about 4,000 Pa to about 6,800 Pa, about 4,000 Pa to about 6,600 Pa, about 4,000 Pa to about 6,400 Pa, about 4,000 Pa to about 6,200 Pa, about 4,000 Pa to about 6,000 Pa, about 4,000 Pa to about 5,800 Pa, about 4,000 Pa to about 5,600 Pa, about 4,000 Pa to about 5,400 Pa, about 4,000 Pa to about 5,200 Pa, about 4,000 Pa to about 5,000 Pa, about 4,000 Pa to about 4,800 Pa, about 4,000 Pa to about 4,600 Pa, about 4,000 Pa to about 4,400 Pa, about 4,000 Pa to about 4,200 Pa, about 4,200 Pa to about 7,000 Pa, about 4,200 Pa to about 6,800 Pa, about 4,200 Pa to about 6,600 Pa, about 4,200 Pa to about 6,400 Pa, about 4,200 Pa to about 6,200 Pa, about 4,200 Pa to about 6,000 Pa, about 4,200 Pa to about 5,800 Pa, about 4,200 Pa to about 5,600 Pa, about 4,200 Pa to about 5,400 Pa, about 4,200 Pa to about 5,200 Pa, about 4,200 Pa to about 5,000 Pa, about 4,200 Pa to about 4,800 Pa, about 4,200 Pa to about 4,600 Pa, about 4,200 Pa to about 4,400 Pa, about 4,400 Pa to about 7,000 Pa, about 4,400 Pa to about 6,800 Pa, about 4,400 Pa to about 6,600 Pa, about 4,400 Pa to about 6,400 Pa, about 4,400 Pa to about 6,200 Pa, about 4,400 Pa to about 6,000 Pa, about 4,400 Pa to about 5,800 Pa, about 4,400 Pa to about 5,600 Pa, about 4,400 Pa to about 5,400 Pa, about 4,400 Pa to about 5,200 Pa, about 4,400 Pa to about 5,000 Pa, about 4,400 Pa to about 4,800 Pa, about 4,400 Pa to about 4,600 Pa, about 4,600 Pa to about 7,000 Pa, about 4,600 Pa to about 6,800 Pa, about 4,600 Pa to about 6,600 Pa, about 4,600 Pa to about 6,400 Pa, about 4,600 Pa to about 6,200 Pa, about 4,600 Pa to about 6,000 Pa, about 4,600 Pa to about 5,800 Pa, about 4,600 Pa to about 5,600WSGR Docket No. 63230-733.601Pa, about 4,600 Pa to about 5,400 Pa, about 4,600 Pa to about 5,200 Pa, about 4,600 Pa to about 5,000 Pa, about 4,600 Pa to about 4,800 Pa, about 4,800 Pa to about 7,000 Pa, about 4,800 Pa to about 6,800 Pa, about 4,800 Pa to about 6,600 Pa, about 4,800 Pa to about 6,400 Pa, about 4,800 Pa to about 6,200 Pa, about 4,800 Pa to about 6,000 Pa, about 4,800 Pa to about 5,800 Pa, about 4,800 Pa to about 5,600 Pa, about 4,800 Pa to about 5,400 Pa, about 4,800 Pa to about 5,200 Pa, about 4,800 Pa to about 5,000 Pa, about 5,000 Pa to about 7,000 Pa, about 5,000 Pa to about 6,800 Pa, about 5,000 Pa to about 6,600 Pa, about 5,000 Pa to about 6,400 Pa, about 5,000 Pa to about 6,200 Pa, about 5,000 Pa to about 6,000 Pa, about 5,000 Pa to about 5,800 Pa, about 5,000 Pa to about 5,600 Pa, about 5,000 Pa to about 5,400 Pa, about 5,000 Pa to about 5,200 Pa, about 5,200 Pa to about 7,000 Pa, about 5,200 Pa to about 6,800 Pa, about 5,200 Pa to about 6,600 Pa, about 5,200 Pa to about 6,400 Pa, about 5,200 Pa to about 6,200 Pa, about 5,200 Pa to about 6,000 Pa, about 5,200 Pa to about 5,800 Pa, about 5,200 Pa to about 5,600 Pa, about 5,200 Pa to about 5,400 Pa, about 5,400 Pa to about 7,000 Pa, about 5,400 Pa to about 6,800 Pa, about 5,400 Pa to about 6,600 Pa, about 5,400 Pa to about 6,400 Pa, about 5,400 Pa to about 6,200 Pa, about 5,400 Pa to about 6,000 Pa, about 5,400 Pa to about 5,800 Pa, about 5,400 Pa to about 5,600 Pa, about 5,600 Pa to about 7,000 Pa, about 5,600 Pa to about 6,800 Pa, about 5,600 Pa to about 6,600 Pa, about 5,600 Pa to about 6,400 Pa, about 5,600 Pa to about 6,200 Pa, about 5,600 Pa to about 6,000 Pa, about 5,600 Pa to about 5,800 Pa, about 5,800 Pa to about 7,000 Pa, about 5,800 Pa to about 6,800 Pa, about 5,800 Pa to about 6,600 Pa, about 5,800 Pa to about 6,400 Pa, about 5,800 Pa to about 6,200 Pa, about 5,800 Pa to about 6,000 Pa, about 6,000 Pa to about 7,000 Pa, about 6,000 Pa to about 6,800 Pa, about 6,000 Pa to about 6,600 Pa, about 6,000 Pa to about 6,400 Pa, about 6,000 Pa to about 6,200 Pa, about 6,200 Pa to about 7,000 Pa, about 6,200 Pa to about 6,800 Pa, about 6,200 Pa to about 6,600 Pa, about 6,200 Pa to about 6,400 Pa, about 6,400 Pa to about 7,000 Pa, about 6,400 Pa to about 6,800 Pa, about 6,400 Pa to about 6,600 Pa, about 6,600 Pa to about 7,000 Pa, about 6,600 Pa to about 6,800 Pa, or about 6.800 Pa to about 7,000 Pa. In some embodiments, the Young’s Modulus of hair applied with the composition has a Young’s Modulus higher than a Young’s Modulus of hair not applied with the composition. In some embodiments, the Young’s Modulus of hair applied with the composition is about 2-fold, about 3-fold, about 4-fold, or about 5 -fold higher than a Young’s Modulus of hair not applied with the composition. In some embodiments, the Young’s Modulus is determined by tensiometer measurements.

[0080] In some embodiments, the elasticity of the hair is determined by measuring a Young’s Modulus of hair. In some embodiments, the Young’s Modulus of hair applied withWSGR Docket No. 63230-733.601the composition is at least about 3,000 Pa, about 3,200 Pa, about 3,400 Pa, about 3,600 Pa, about 3,800 Pa, about 4,000 Pa, about 4,200 Pa, about 4,400 Pa, about 4,600 Pa, about 4,800 Pa, about 5,000 Pa, about 5,200 Pa, about 5,400 Pa, about 5,600 Pa, about 5,800 Pa, about 6,000 Pa, about 6,200 Pa, about 6,400 Pa, about 6,600 Pa, about 6,800 Pa, about 7,000 Pa, or about 7,200 Pa. In some embodiments, the Young’s Modulus of hair applied with the composition is about 3,000 Pa to about 7,000 Pa, about 3,000 Pa to about 6,800 Pa, about 3,000 Pa to about 6,600 Pa, about 3,000 Pa to about 6,400 Pa, about 3,000 Pa to about 6,200 Pa, about 3,000 Pa to about 6,000 Pa, about 3,000 Pa to about 5,800 Pa, about 3,000 Pa to about 5,600 Pa, about 3,000 Pa to about 5,400 Pa, about 3,000 Pa to about 5,200 Pa, about 3,000 Pa to about 5,000 Pa, about 3,000 Pa to about 4,800 Pa, about 3,000 Pa to about 4,600 Pa, about 3,000 Pa to about 4,400 Pa, about 3,000 Pa to about 4,200 Pa, about 3,200 Pa to about 7,000 Pa, about 3,200 Pa to about 6,800 Pa, about 3,200 Pa to about 6,600 Pa, about 3,200 Pa to about 6,400 Pa, about 3,200 Pa to about 6,200 Pa, about 3,200 Pa to about 6,000 Pa, about 3,200 Pa to about 5,800 Pa, about 3,200 Pa to about 5,600 Pa, about 3,200 Pa to about 5,400 Pa, about 3,200 Pa to about 5,200 Pa, about 3,200 Pa to about 5,000 Pa, about 3,200 Pa to about 4,800 Pa, about 3,200 Pa to about 4,600 Pa, about 3,200 Pa to about 4,400 Pa, about 3,200 Pa to about 4,200 Pa, about 3,400 Pa to about 7,000 Pa, about 3,400 Pa to about 6,800 Pa, about 3,400 Pa to about 6,600 Pa, about 3,400 Pa to about 6,400 Pa, about 3,400 Pa to about 6,200 Pa, about 3,400 Pa to about 6,000 Pa, about 3,400 Pa to about 5,800 Pa, about 3,400 Pa to about 5,600 Pa, about 3,400 Pa to about 5,400 Pa, about 3,400 Pa to about 5,200 Pa, about 3,400 Pa to about 5,000 Pa, about 3,400 Pa to about 4,800 Pa, about 3,400 Pa to about 4,600 Pa, about 3,400 Pa to about 4,400 Pa, about 3,400 Pa to about 4,200 Pa, about 3,600 Pa to about 7,000 Pa, about 3,600 Pa to about 6,800 Pa, about 3,600 Pa to about 6,600 Pa, about 3,600 Pa to about 6,400 Pa, about 3,600 Pa to about 6,200 Pa, about 3,600 Pa to about 6,000 Pa, about 3,600 Pa to about 5,800 Pa, about 3,600 Pa to about 5,600 Pa, about 3,600 Pa to about 5,400 Pa, about 3,600 Pa to about 5,200 Pa, about 3,600 Pa to about 5,000 Pa, about 3,600 Pa to about 4,800 Pa, about 3,600 Pa to about 4,600 Pa, about 3,600 Pa to about 4,400 Pa, about 3,600 Pa to about 4,200 Pa, about 3,800 Pa to about 7,000 Pa, about 3,800 Pa to about 6,800 Pa, about 3,800 Pa to about 6,600 Pa, about 3,800 Pa to about 6,400 Pa, about 3,800 Pa to about 6,200 Pa, about 3,800 Pa to about 6,000 Pa, about 3,800 Pa to about 5,800 Pa, about 3,800 Pa to about 5,600 Pa, about 3,800 Pa to about 5,400 Pa, about 3,800 Pa to about 5,200 Pa, about 3,800 Pa to about 5,000 Pa, about 3,800 Pa to about 4,800 Pa, about 3,800 Pa to about 4,600 Pa, about 3,800 Pa to about 4,400 Pa, about 3,800 Pa to about 4,200 Pa, about 4,000 Pa to about 7,000 Pa, about 4,000 Pa to about 6,800WSGR Docket No. 63230-733.601Pa, about 4,000 Pa to about 6,600 Pa, about 4,000 Pa to about 6,400 Pa, about 4,000 Pa to about 6,200 Pa, about 4,000 Pa to about 6,000 Pa, about 4,000 Pa to about 5,800 Pa, about 4,000 Pa to about 5,600 Pa, about 4,000 Pa to about 5,400 Pa, about 4,000 Pa to about 5,200 Pa, about 4,000 Pa to about 5,000 Pa, about 4,000 Pa to about 4,800 Pa, about 4,000 Pa to about 4,600 Pa, about 4,000 Pa to about 4,400 Pa, about 4,000 Pa to about 4,200 Pa, about 4,200 Pa to about 7,000 Pa, about 4,200 Pa to about 6,800 Pa, about 4,200 Pa to about 6,600 Pa, about 4,200 Pa to about 6,400 Pa, about 4,200 Pa to about 6,200 Pa, about 4,200 Pa to about 6,000 Pa, about 4,200 Pa to about 5,800 Pa, about 4,200 Pa to about 5,600 Pa, about 4,200 Pa to about 5,400 Pa, about 4,200 Pa to about 5,200 Pa, about 4,200 Pa to about 5,000 Pa, about 4,200 Pa to about 4,800 Pa, about 4,200 Pa to about 4,600 Pa, about 4,200 Pa to about 4,400 Pa, about 4,400 Pa to about 7,000 Pa, about 4,400 Pa to about 6,800 Pa, about 4,400 Pa to about 6,600 Pa, about 4,400 Pa to about 6,400 Pa, about 4,400 Pa to about 6,200 Pa, about 4,400 Pa to about 6,000 Pa, about 4,400 Pa to about 5,800 Pa, about 4,400 Pa to about 5,600 Pa, about 4,400 Pa to about 5,400 Pa, about 4,400 Pa to about 5,200 Pa, about 4,400 Pa to about 5,000 Pa, about 4,400 Pa to about 4,800 Pa, about 4,400 Pa to about 4,600 Pa, about 4,600 Pa to about 7,000 Pa, about 4,600 Pa to about 6,800 Pa, about 4,600 Pa to about 6,600 Pa, about 4,600 Pa to about 6,400 Pa, about 4,600 Pa to about 6,200 Pa, about 4,600 Pa to about 6,000 Pa, about 4,600 Pa to about 5,800 Pa, about 4,600 Pa to about 5,600 Pa, about 4,600 Pa to about 5,400 Pa, about 4,600 Pa to about 5,200 Pa, about 4,600 Pa to about 5,000 Pa, about 4,600 Pa to about 4,800 Pa, about 4,800 Pa to about 7,000 Pa, about 4,800 Pa to about 6,800 Pa, about 4,800 Pa to about 6,600 Pa, about 4,800 Pa to about 6,400 Pa, about 4,800 Pa to about 6,200 Pa, about 4,800 Pa to about 6,000 Pa, about 4,800 Pa to about 5,800 Pa, about 4,800 Pa to about 5,600 Pa, about 4,800 Pa to about 5,400 Pa, about 4,800 Pa to about 5,200 Pa, about 4,800 Pa to about 5,000 Pa, about 5,000 Pa to about 7,000 Pa, about 5,000 Pa to about 6,800 Pa, about 5,000 Pa to about 6,600 Pa, about 5,000 Pa to about 6,400 Pa, about 5,000 Pa to about 6,200 Pa, about 5,000 Pa to about 6,000 Pa, about 5,000 Pa to about 5,800 Pa, about 5,000 Pa to about 5,600 Pa, about 5,000 Pa to about 5,400 Pa, about 5,000 Pa to about 5,200 Pa, about 5,200 Pa to about 7,000 Pa, about 5,200 Pa to about 6,800 Pa, about 5,200 Pa to about 6,600 Pa, about 5,200 Pa to about 6,400 Pa, about 5,200 Pa to about 6,200 Pa, about 5,200 Pa to about 6,000 Pa, about 5,200 Pa to about 5,800 Pa, about 5,200 Pa to about 5,600 Pa, about 5,200 Pa to about 5,400 Pa, about 5,400 Pa to about 7,000 Pa, about 5,400 Pa to about 6,800 Pa, about 5,400 Pa to about 6,600 Pa, about 5,400 Pa to about 6,400 Pa, about 5,400 Pa to about 6,200 Pa, about 5,400 Pa to about 6,000 Pa, about 5,400 Pa to about 5,800 Pa, about 5,400 Pa to about 5,600 Pa, about 5,600 Pa toWSGR Docket No. 63230-733.601about 7,000 Pa, about 5,600 Pa to about 6,800 Pa, about 5,600 Pa to about 6,600 Pa, about 5,600 Pa to about 6,400 Pa, about 5,600 Pa to about 6,200 Pa, about 5,600 Pa to about 6,000 Pa, about 5,600 Pa to about 5,800 Pa, about 5,800 Pa to about 7,000 Pa, about 5,800 Pa to about 6,800 Pa, about 5,800 Pa to about 6,600 Pa, about 5,800 Pa to about 6,400 Pa, about 5.800 Pa to about 6,200 Pa, about 5,800 Pa to about 6,000 Pa, about 6,000 Pa to about 7,000 Pa, about 6,000 Pa to about 6,800 Pa, about 6,000 Pa to about 6,600 Pa, about 6,000 Pa to about 6,400 Pa, about 6,000 Pa to about 6,200 Pa, about 6,200 Pa to about 7,000 Pa, about 6,200 Pa to about 6,800 Pa, about 6,200 Pa to about 6,600 Pa, about 6,200 Pa to about 6,400 Pa, about 6,400 Pa to about 7,000 Pa, about 6,400 Pa to about 6,800 Pa, about 6,400 Pa to about 6,600 Pa, about 6,600 Pa to about 7,000 Pa, about 6,600 Pa to about 6,800 Pa, or about 6.800 Pa to about 7,000 Pa. In some embodiments, the Young’s Modulus of hair applied with the composition has a Young’s Modulus higher than a Young’s Modulus of hair not applied with the composition. In some embodiments, the Young’s Modulus of hair applied with the composition is about 2-fold, about 3-fold, about 4-fold, or about 5 -fold higher than a Young’s Modulus of hair not applied with the composition. In some embodiments, the Young’s Modulus is determined by tensiometer measurements.

[0081] In some embodiments, the strength of hair is determined by measuring a break stress of hair. In some embodiments, the break stress of hair applied with the composition is about 200 Pa to about 500 Pa, about 200 Pa to about 475 Pa, about 200 Pa to about 450 Pa, about 200 Pa to about 425 Pa, about 200 Pa to about 400 Pa, about 200 Pa to about 375 Pa, about 200 Pa to about 350 Pa, about 200 Pa to about 325 Pa, about 200 Pa to about 300 Pa, about 200 Pa to about 275 Pa, about 200 Pa to about 250 Pa, about 200 Pa to about 225 Pa, about 225 Pa to about 500 Pa, about 225 Pa to about 475 Pa, about 225 Pa to about 450 Pa, about 225 Pa to about 425 Pa, about 225 Pa to about 400 Pa, about 225 Pa to about 375 Pa, about 225 Pa to about 350 Pa, about 225 Pa to about 325 Pa, about 225 Pa to about 300 Pa, about 225 Pa to about 275 Pa, about 225 Pa to about 250 Pa, about 250 Pa to about 500 Pa, about 250 Pa to about 475 Pa, about 250 Pa to about 450 Pa, about 250 Pa to about 425 Pa, about 250 Pa to about 400 Pa, about 250 Pa to about 375 Pa, about 250 Pa to about 350 Pa, about 250 Pa to about 325 Pa, about 250 Pa to about 300 Pa, about 250 Pa to about 275 Pa, about 275 Pa to about 500 Pa, about 275 Pa to about 475 Pa, about 275 Pa to about 450 Pa, about 275 Pa to about 425 Pa, about 275 Pa to about 400 Pa, about 275 Pa to about 375 Pa, about 275 Pa to about 350 Pa, about 275 Pa to about 325 Pa, about 275 Pa to about 300 Pa, about 300 Pa to about 500 Pa, about 300 Pa to about 475 Pa, about 300 Pa to about 450 Pa, about 300 Pa to about 425 Pa, about 300 Pa to about 400 Pa, about 300 Pa to about 375 Pa,WSGR Docket No. 63230-733.601about 300 Pa to about 350 Pa, about 300 Pa to about 325 Pa, about 325 Pa to about 500 Pa, about 325 Pa to about 475 Pa, about 325 Pa to about 450 Pa, about 325 Pa to about 425 Pa, about 325 Pa to about 400 Pa, about 325 Pa to about 375 Pa, about 325 Pa to about 350 Pa, about 350 Pa to about 500 Pa, about 350 Pa to about 475 Pa, about 350 Pa to about 450 Pa, about 350 Pa to about 425 Pa, about 350 Pa to about 400 Pa, about 350 Pa to about 375 Pa, about 375 Pa to about 500 Pa, about 375 Pa to about 475 Pa, about 375 Pa to about 450 Pa, about 375 Pa to about 425 Pa, about 375 Pa to about 400 Pa, about 400 Pa to about 500 Pa, about 400 Pa to about 475 Pa, about 400 Pa to about 450 Pa, about 400 Pa to about 425 Pa, about 425 Pa to about 500 Pa, about 425 Pa to about 475 Pa, about 425 Pa to about 450 Pa, about 450 Pa to about 500 Pa, about 450 Pa to about 475 Pa, or about 475 Pa to about 500 Pa. In some embodiments, the break stress of hair applied with the composition is at least about 200 Pa, about 225 Pa, about 250 Pa, about 275 Pa, about 300 Pa, about 325 Pa, about 350 Pa, about 375 Pa, about 400 Pa, about 425 Pa, about 450 Pa, about 475 Pa, or at least about 500 Pa. In some embodiments, the break stress of hair applied with the composition has a break stress about 2-fold, about 3-fold, about 4-fold, or about 5-fold higher than a break stress of hair not applied with the composition.

[0082] In some aspects, described herein is a method of shielding a hair of a subject from ultraviolet (UV) light. In some embodiments, the method comprises applying a composition to the hair of the subject, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601, or a polymer thereof, or a combination of two or more thereof. InHOpolymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof. In some embodiments, the compound of the HNcomposition has the structureor a polymer thereof. In some embodiments,O^OO Othe compound of the composition has the structureor a polymer thereof. In some embodiments, the compound of the composition has the structureor a polymer thereof. In some embodiments, the compound or polymer thereof absorbs UV light having a wavelength of about 230 nm to about 400 nm. In some embodiments, the compound or polymer thereof absorbs light having a wavelength of about 250 nm to about 400 nm. In some embodiments, the compound or polymer thereofWSGR Docket No. 63230-733.601absorbs light having a wavelength of about 280 nm to about 400 nm. In some embodiments, the compound or polymer thereof absorbs minimal light having a wavelength of at least about 400 nm.

[0083] In some embodiments, the shielding is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0084] In some aspects, provided herein are methods of preventing or minimizing penetration of UV light into a hair cortex of a subject. In some embodiments, the method comprises applying a composition to the hair, the composition comprising a compound HOhaving the structure: HOof two or more thereof. In some embodiments, the compound of the composition has thestructureor a polymer thereof. In some embodiments, the compound of the H HO^^X^N Ocomposition has the structureHO x / OHOr a polymer thereof. In someembodiments, the compound of the composition has the structurepolymer thereof. In some embodiments, the compound of the composition has the structureWSGR Docket No. 63230-733.601or a polymer thereof. In some embodiments, the compound ofthe composition has the structure

[0085] In some embodiments, the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0086] In some embodiments, an SEM image of hair applied with the composition and SEM image of hair not applied with the composition are taken. In some instances, a comparison of the SEM image of hair applied with the composition and the SEM image of hair not applied with the composition is made. In some instances, the SEM image of hair applied with the composition shows a smoother surface compared to the SEM image of hair not applied with the composition.

[0087] In some aspects, provided herein are methods of preventing or minimizing formation of free radicals in a hair of a subject. In some embodiments, the method comprises applying a composition to the hair or the scalp of the subject, the composition comprising a H HOcompound having the structure:HOWSGR Docket No. 63230-733.601of two or more thereof.

[0088] In some embodiments, the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0089] In some aspects, provided herein are methods of retaining the color of hair. In some embodiments, the method comprises applying a composition to the hair. In someHembodiments, the composition comprises a compound having the structure: HO X, or a polymer thereof, or a combination of two or more thereof. InWSGR Docket No. 63230-733.601Hsome embodiments, the compound of the composition has the structure JJ or a polymer thereof. In some embodiments, the compound of the composition has the structureHHO OHor apolymer thereof. In some embodiments, the compound of thethereof. In some embodiments, the compound of the composition has the structurethe hair color is retained in hair. In some embodiments, at least about 65% of the hair color is retained in hair. In some embodiments, at least about 70% of the hair color is retained in hair. In some embodiments, at least about 75% of the hair color is retained in hair. In some embodiments, at least about 80% of the hair color is retained in hair. In some embodiments, at least about 85% of the hair color is retained in hair. In some embodiments, at least about 90% of the hair color is retained in hair. In some embodiments, at least about 91% of the hair color is retained in hair. In some embodiments, at least about 92% of the hair color is retained in hair. In some embodiments, at least about 93% of the hair color is retained in hair. In some embodiments, at least about 94% of the hair color is retained in hair. In some embodiments, at least about 95% of the hair color is retained in hair. In some embodiments, at least aboutWSGR Docket No. 63230-733.60196% of the hair color is retained in hair. In some embodiments, at least about 97% of the hair color is retained in hair. In some embodiments, at least about 98% of the hair color is retained in hair. In some embodiments, at least about 99% of the hair color is retained in hair. In some embodiments, about 100% of the hair color is retained in hair. In some embodiments, about 60% to about 100%, about 60% to about 99%, about 60% to about 98%, about 60% to about 97%, about 60% to about 96%, about 60% to about 95%, about 60% to about 94%, about 60% to about 93%, about 60% to about 92%, about 60% to about 91%, about 60% to about 90%, about 60% to about 85%, about 60% to about 80%, about 60% to about 75%, about 60% to about 70%, about 60% to about 65%, about 65% to about 100%, about 65% to about 99%, about 65% to about 98%, about 65% to about 97%, about 65% to about 96%, about 65% to about 95%, about 65% to about 94%, about 65% to about 93%, about 65% to about 92%, about 65% to about 91%, about 65% to about 90%, about 65% to about 85%, about 65% to about 80%, about 65% to about 75%, about 65% to about 70%, about 70% to about 100%, about 70% to about 99%, about 70% to about 98%, about 70% to about 97%, about 70% to about 96%, about 70% to about 95%, about 70% to about 94%, about 70% to about 93%, about 70% to about 92%, about 70% to about 91%, about 70% to about 90%, about 70% to about 85%, about 70% to about 80%, about 70% to about 75%, about 75% to about 100%, about 75% to about 99%, about 75% to about 98%, about 75% to about 97%, about 75% to about 96%, about 75% to about 95%, about 75% to about 94%, about 75% to about 93%, about 75% to about 92%, about 75% to about 91%, about 75% to about 90%, about 75% to about 85%, about 75% to about 80%, about 80% to about 100%, about 80% to about 99%, about 80% to about 98%, about 80% to about 97%, about 80% to about 96%, about 80% to about 95%, about 80% to about 94%, about 80% to about 93%, about 80% to about 92%, about 80% to about 91%, about 80% to about 90%, about 80% to about 85%, about 85% to about 100%, about 85% to about 99%, about 85% to about 98%, about 85% to about 97%, about 85% to about 96%, about 85% to about 95%, about 85% to about 94%, about 85% to about 93%, about 85% to about 92%, about 85% to about 91%, about 85% to about 90%, about 90% to about 100%, about 90% to about 99%, about 90% to about 98%, about 90% to about 97%, about 90% to about 96%, about 90% to about 95%, about 90% to about 94%, about 90% to about 93%, about 90% to about 92%, about 90% to about 91%, about 91% to about 100%, about 91% to about 99%, about 91% to about 98%, about 91% to about 97%, about 91% to about 96%, about 91% to about 95%, about 91% to about 94%, about 91% to about 93%, about 91% to about 92%, about 92% to about 100%, about 92% to about 99%, about 92% to about 98%, about 92% to about 97%, about 92% to about 96%, aboutWSGR Docket No. 63230-733.60192% to about 95%, about 92% to about 94%, about 92% to about 93%, about 93% to about 100%, about 93% to about 99%, about 93% to about 98%, about 93% to about 97%, about 93% to about 96%, about 93% to about 95%, about 93% to about 94%, about 94% to about 100%, about 94% to about 99%, about 94% to about 98%, about 94% to about 97%, about 94% to about 96%, about 94% to about 95%, about 95% to about 100%, about 95% to about 99%, about 95% to about 98%, about 95% to about 97%, or about 95% to about 96% of the hair color is retained in hair. In some embodiments the retention of hair color in hair is determined by time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, UV absorbance spectroscopy, or a combination thereof.

[0090] In some embodiments, the retention of hair color is determined by measuring a hair color loss (ΔE) of less than about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 15, about 20, or about 25. In some embodiments, the ΔE is at most about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1. In some embodiments, ΔE is about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 9, about 1 to about 8, about 1 to about 7, about 1 to about 6, about 1 to about 5, about 1 to about 4, about 1 to about 3, about 1 to about 2, about 2 to about 25, about 2 to about 20, about 2 to about 15, about 2 to about 10, about 2 to about 9, about 2 to about 8, about 2 to about 7, about 2 to about 6, about 2 to about 5, about 2 to about 4, about 2 to about 3, about 3 to about 25, about 3 to about 20, about 3 to about 15, about 3 to about 10, about 3 to about 9, about 3 to about 8, about 3 to about 7, about 3 to about 6, about 3 to about 5, about 3 to about 4, about 4 to about 25, about 4 to about 20, about 4 to about 15, about 4 to about 10, about 4 to about 9, about 4 to about 8, about 4 to about 7, about 4 to about 6, about 4 to about 5, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 5 to about 9, about 5 to about 8, about 5 to about 7, about 5 to about 6, about 6 to about 25, about 6 to about 20, about 6 to about 15, about 6 to about 10, about 6 to about 9, about 6 to about 8, about 6 to about 7, about 7 to about 25, about 7 to about 20, about 7 to about 15, about 7 to about 10, about 7 to about 9, about 7 to about 8, about 8 to about 25, about 8 to about 20, about 8 to about 15, about 8 to about 10, about 8 to about 9, about 9 to about 25, about 9 to about 20, about 9 to about 15, about 9 to about 10, about 10 to about 25, about 10 to about 20, about 10 to about 15, about 15 to about 25, about 15 to about 20, or about 20 to about 25. In some instances, the hair color loss is determined by a color fade assay.

[0091] In some embodiments, the hair applied with the composition exhibits a hair color loss (ΔE). In some embodiments, the hair applied with the composition exhibits a ΔE of lessWSGR Docket No. 63230-733.601than about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1. In some embodiments, the hair color loss (ΔE) is determined by a color fade assay. In some embodiments, the hair has been applied with the composition, and ΔE is determined of hair applied with the composition and compared against hair not applied with the composition.. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 50. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 45. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 40. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 35. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 30. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 25. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 20. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 15. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 10. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 9. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 8. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 7. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 6. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 5. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 4. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 3. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 2. In some embodiments, the hair exhibits a hair color loss (ΔE) of less than about 1. In some embodiments, the hair exhibits a hair color loss (ΔE) of about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay. In some embodiments, the hair exhibits a ΔE of about 1 to about 50, about 1 to about 45, about 1 to about 40, about 1 to about 35, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 15, about 1 to about 10, about 1 to about 9, about 1 to about 8, about 1 to about 7, about 1 to about 6, about 1 to about 5, about 1 to about 4, about 1 to about 3, about 1 to about 2, about 2 to about 50, about 2 to about 45, about 2 to about 40, about 2 to about 35, about 2 to about 30, about 2 to about 25, about 2 to about 20, about 2 to about 15, about 2 to about 10, about 2 to about 9, about 2 to about 8, about 2 to about 7, about 2 to about 6, about 2 to about 5, about 2 to about 4, about 2 to about 3, about 3 to about 50,WSGR Docket No. 63230-733.601about 3 to about 45, about 3 to about 40, about 3 to about 35, about 3 to about 30, about 3 to about 25, about 3 to about 20, about 3 to about 15, about 3 to about 10, about 3 to about 9, about 3 to about 8, about 3 to about 7, about 3 to about 6, about 3 to about 5, about 3 to about 4, about 4 to about 50, about 4 to about 45, about 4 to about 40, about 4 to about 35, about 4 to about 30, about 4 to about 25, about 4 to about 20, about 4 to about 15, about 4 to about 10, about 4 to about 9, about 4 to about 8, about 4 to about 7, about 4 to about 6, about 4 to about 5, about 5 to about 50, about 5 to about 45, about 5 to about 40, about 5 to about 35, about 5 to about 30, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 5 to about 9, about 5 to about 8, about 5 to about 7, about 5 to about 6, about 6 to about 50, about 6 to about 45, about 6 to about 40, about 6 to about 35, about 6 to about 30, about 6 to about 25, about 6 to about 20, about 6 to about 15, about 6 to about 10, about 6 to about 9, about 6 to about 8, about 6 to about 7, about 7 to about 50, about 7 to about 45, about 7 to about 40, about 7 to about 35, about 7 to about 30, about 7 to about 25, about 7 to about 20, about 7 to about 15, about 7 to about 10, about 7 to about 9, about 7 to about 8, about 8 to about 50, about 8 to about 45, about 8 to about 40, about 8 to about 35, about 8 to about 30, about 8 to about 25, about 8 to about 20, about 8 to about 15, about 8 to about 10, about 8 to about 9, about 9 to about 50, about 9 to about 45, about 9 to about 40, about 9 to about 35, about 9 to about 30, about 9 to about 25, about 9 to about 20, about 9 to about 15, about 9 to about 10, about 10 to about 50, about 10 to about 45, about 10 to about 40, or about 10 to about 35.

[0092] In some embodiments, the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

[0093] In some embodiments, the hair applied with the composition exhibits improved color retention, health, elasticity, strength, or a combination thereof.

[0094] In some embodiments, the composition is applied to the hair at a frequency. In some embodiments, the frequency comprises about once a day, about twice a day, about three times a day, about once every two days, about once every three days, about once every four days, about once every five days, about once every six days, about once every seven days, about twice every three days, twice every five days, about twice every seven days, about once per week, about twice per week, about three times per week, about four times per week, about five times per week, about six times per week, or a combination thereof.WSGR Docket No. 63230-733.601

[0095] In some embodiments, the composition is applied to the hair at a frequency for a period of time. In some embodiments, the period of time comprises at least about 1 day, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 7 days, about 8 days, about 9 days, about 10 days, about 11 days, about 12 days, about 13 days, about 14 days, about 15 days, about 16 days, about 17 days, about 18 days, about 19 days, about 20 days, about 21 days, about 22 days, about 23 days, about 24 days, about 25 days, about 26 days, about 27 days, about 28 days, about 29 days, about 30 days, about 31 days, about 1 month, about 2 months, about 3 months, about 4 months, about 5 months, about 6 months, about 7 months, about 8 months, about 9 months, about 10 months, about 11 months, or at least about 12 months. In some embodiments, the period of time comprises about 1 day to about 6 months, about 2 days to about 5 months, about 3 days to about 4 months, about 4 days to about 3 months, about 5 days to about 2 months, about 6 days to about 1 months, about 7 days to about 31 days, about 8 days to about 30 days, about 9 days to about 29 days, about 10 days to about 28 days, about 11 days to about 27 days, about 12 days to about 26 days, about 13 days to about 25 days, about 14 days to about 24 days, about 15 days to about 23 days, about 16 days to about 22 days, about 17 days to about 21 days, or about 18 days to about 20 days.

[0096] In some embodiments, the composition is coated over a total surface of the hair on the scalp of the subject. In some embodiments, the composition is coated over about 5% to about 100% of the total surface of the hair on the scalp of the subject. In some embodiments, the composition is coated over about 5% to about 100%, about 5% to about 95%, about 5% to about 90%, about 5% to about 85%, about 5% to about 80%, about 5% to about 75%, about 5% to about 70%, about 5% to about 65%, about 5% to about 60%, about 5% to about 55%, about 5% to about 50%, about 5% to about 45%, about 5% to about 40%, about 5% to about 35%, about 5% to about 30%, about 5% to about 25%, about 5% to about 20%, about 10% to about 100%, about 10% to about 95%, about 10% to about 90%, about 10% to about 85%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 10% to about 20%, about 15% to about 100%, about 15% to about 95%, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%,WSGR Docket No. 63230-733.601about 15% to about 25%, about 15% to about 20%, about 20% to about 100%, about 20% to about 95%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 20% to about 35%, about 20% to about 30%, about 20% to about 25%, about 25% to about 100%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 25% to about 35%, about 25% to about 30%, about 30% to about 100%, about 30% to about 95%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 30% to about 45%, about 30% to about 40%, or about 30% to about 35% of the total surface of the hair on the scalp of the subject.

[0097] In some embodiments, the composition is coated over at least about 10% of the total surface of the hair on the scalp of the subject. In some embodiments, the composition is coated over at least at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 100% of the total surface of the hair on the scalp of the subject.

[0098] In some embodiments, the composition is substantially heterogeneously coated over the surface of the hair on the scalp of the subject. In some embodiments, the composition is substantially uniformly coated over the surface of the hair on the scalp of the subject.

[0099] In some embodiments, applying the composition to the hair comprises covering at least about 10% to about 100% of the total surface area of the hair. In some embodiments, the composition covers about 10% to about 100%, about 10% to about 95%, about 10% to about 90%, about 10% to about 85%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 10% to about 20%, about 15% to about 100%, about 15% to about 95%, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to aboutWSGR Docket No. 63230-733.60170%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 15% to about 25%, about 15% to about 20%, about 20% to about 100%, about 20% to about 95%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 20% to about 35%, about 20% to about 30%, about 20% to about 25%, about 25% to about 100%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 25% to about 35%, about 25% to about 30%, about 30% to about 100%, about 30% to about 95%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 30% to about 45%, about 30% to about 40%, about 30% to about 35%, about 35% to about 100%, about 35% to about 95%, about 35% to about 90%, about 35% to about 85%, about 35% to about 80%, about 35% to about 75%, about 35% to about 70%, about 35% to about 65%, about 35% to about 60%, about 35% to about 55%, about 35% to about 50%, about 35% to about 45%, or about 35% to about 40% of the total surface area of the hair. In some embodiments, the composition covers at least at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, or about 95%. In some embodiments the composition covers about 100% of the total surface area of the hair.

[0100] In some embodiments, applying the composition to the hair comprises covering at least about 10% to about 100% of a target surface area of the hair. In some embodiments, the composition covers about 10% to about 100%, about 10% to about 95%, about 10% to about 90%, about 10% to about 85%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 10% to about 20%, about 15% to about 100%, about 15% to about 95%, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to aboutWSGR Docket No. 63230-733.60170%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 15% to about 25%, about 15% to about 20%, about 20% to about 100%, about 20% to about 95%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 20% to about 35%, about 20% to about 30%, about 20% to about 25%, about 25% to about 100%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 25% to about 35%, about 25% to about 30%, about 30% to about 100%, about 30% to about 95%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 30% to about 45%, about 30% to about 40%, about 30% to about 35%, about 35% to about 100%, about 35% to about 95%, about 35% to about 90%, about 35% to about 85%, about 35% to about 80%, about 35% to about 75%, about 35% to about 70%, about 35% to about 65%, about 35% to about 60%, about 35% to about 55%, about 35% to about 50%, about 35% to about 45%, or about 35% to about 40% of the target surface area of the hair. In some embodiments, the composition covers at least at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, or about 95% % of the target surface area of the hair. In some embodiments the composition covers about 100% of the target surface area of the hair. In some embodiments, the target surface area of the hair is the surface area of the hair on the crown of a head.

[0101] In some embodiments, after applying the composition to the hair, about 1% to about 20% of UV light is permitted into the cortex of the hair. In some embodiments, applying the composition of hair comprises permitting about 1% to about 50%, about 1% to about 45%, about 1% to about 40%, about 1% to about 35%, about 1% to about 30%, about 1% to about 25%, about 1% to about 20%, about 1% to about 15%, about 1% to about 10%, about 1% to about 5%, about 2% to about 50%, about 2% to about 45%, about 2% to about 40%, about 2% to about 35%, about 2% to about 30%, about 2% to about 25%, about 2% to about 20%, about 2% to about 15%, about 2% to about 10%, about 2% to about 5%, aboutWSGR Docket No. 63230-733.6015% to about 50%, about 5% to about 45%, about 5% to about 40%, about 5% to about 35%, about 5% to about 30%, about 5% to about 25%, about 5% to about 20%, about 5% to about 15%, about 5% to about 10% of UV light to penetrate into the hair cortex. In some embodiments, the amount of UV light penetrating into the hair cortex is determined with UV-vis spectroscopy, reflectance spectroscopy, TEM, SEM, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.Methods for Scalp

[0102] In some aspects, provided herein are methods for protecting scalp of a subject from damage by ultraviolet (UV) light. In some embodiments, the method comprises applying a composition to the scalp the subject, the composition comprising a compound having theof two or more thereof. In some embodiments, the compound of the composition has thestructureIn some embodiments, the compound of the composition has the HpstructureHO XJCM OH. In some embodiments, the compound of the compositionhas the structureIn some embodiments, the compound of the compositionWSGR Docket No. 63230-733.601

[0103] In some embodiments, the damage is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0104] In some aspects, provided herein are methods of shielding a scalp of a subject from ultraviolet (UV) light. In some embodiments, the method comprises applying a composition to the scalp of the subject, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601Hsome embodiments, the compound of the composition has the structureu.x >. In some embodiments, the compound of the composition has the structureHHO OH in some embodiments, the compound of the composition has theIn some embodiments, the compound of the composition has thestructure. In some embodiments, the compound of theor the polymer thereof absorbs UV light having a wavelength of about 280 nm to about 400 nm.

[0105] In some embodiments, the shielding is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a colorWSGR Docket No. 63230-733.601fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, UV absorbance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0106] In some aspects, provided herein are methods of preventing or minimizing penetration of UV light into a scalp of a subject. In some embodiments, the method comprises applying a composition to the scalp, the composition comprising a compoundof two or more thereof. In some embodiments, the compound of the composition has thestructureIn some embodiments, the compound of the composition has the H HO-^^s^-N,0structureHO OH . In some embodiments, the compound of the compositionhas the structureIn some embodiments, the compound of the compositionWSGR Docket No. 63230-733.601has the structure. In some embodiments, the compound of the

[0107] In some embodiments, the preventing or minimizing penetration of UV light into scalp is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0108] In some aspects, provided herein are methods of preventing or minimizing formation of free radicals in a scalp of a subject. In some embodiments, the method comprises applying a composition to the scalp of the subject, the composition comprising aof two or more thereof. In some embodiments, the compound of the composition has theWSGR Docket No. 63230-733.601structureIn some embodiments, the compound of the composition has the Hstructure HO T EH OH. In some embodiments, the compound of the compositionIn some embodiments, the compound of the compositionhas the structure In some embodiments, the compound of the

[0109] In some embodiments, the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0110] In some aspects, provided herein are methods of coating a scalp of a subject. In some embodiments, the method comprises applying a composition to the scalp of the subject, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601Hsome embodiments, the compound of the composition has the structureu.x >. In some embodiments, the compound of the composition has the structureHHO XJLH OH in some embodiments, the compound of the composition has thestructure. In some embodiments, the compound of theWSGR Docket No. 63230-733.601composition is coated over a surface of the scalp of the subject.

[0111] In some embodiments, the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0112] In some embodiments, the composition is coated over about 1% to about 100% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over about 1% to about 100%, about 1% to about 95%, about 1% to about 90%, about 1% to about 85%, about 1% to about 80%, about 1% to about 75%, about 1% to about 70%, about 1% to about 65%, about 1% to about 60%, about 1% to about 55%, about 1% to about 50%, about 1% to about 45%, about 1% to about 40%, about 1% to about 35%, about 1% to about 30%, about 1% to about 25%, about 1% to about 20%, about 1% to about 15%, about 1% to about 10%, about 1% to about 5%, about 5% to about 100%, about 5% to about 95%, about 5% to about 90%, about 5% to about 85%, about 5% to about 80%, about 5% to about 75%, about 5% to about 70%, about 5% to about 65%, about 5% to about 60%, about 5% to about 55%, about 5% to about 50%, about 5% to about 45%, about 5% to about 40%, about 5% to about 35%, about 5% to about 30%, about 5% to about 25%, about 5% to about 20%, about 5% to about 15%, about 5% to about 10%, about 10% to about 100%, about 10% to about 95%, about 10% to about 90%, about 10% to about 85%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 10% to about 20%, about 10% to about 15%, about 15% to about 100%, about 15% to about 95%, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to aboutWSGR Docket No. 63230-733.60145%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 15% to about 25%, about 15% to about 20%, about 20% to about 100%, about 20% to about 95%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 20% to about 35%, about 20% to about 30%, about 20% to about 25%, about 25% to about 100%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 25% to about 35%, about 25% to about 30%, about 30% to about 100%, about 30% to about 95%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 30% to about 45%, about 30% to about 40%, about 30% to about 35%, about 35% to about 100%, about 35% to about 95%, or about 35% to about 90% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, or about 95% of the total surface of the scalp of the subject. In some embodiments, the amount of coverage of the composition over the scalp of the subject is determined by UV-vis spectroscopy, reflectance spectroscopy, TEM, SEM, FTIR spectroscopy, Raman spectroscopy, TEWL analysis, corneometry, or a combination thereof.

[0113] In some embodiments, the composition is applied to the scalp at a frequency. In some embodiments, the frequency comprises about once a day, about twice a day, about three times a day, about once every two days, about once every three days, about once every four days, about once every five days, about once every six days, about once every seven days, about twice every three days, twice every five days, about twice every seven days, about once per week, about twice per week, about three times per week, about four times per week, about five times per week, about six times per week, or a combination thereof.

[0114] In some embodiments, the composition is applied to the scalp at a frequency for a period of time. In some embodiments, the period of time comprises at least about 1 day, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 7 days, about 8 days, about 9 days, about 10 days, about 11 days, about 12 days, about 13 days, about 14WSGR Docket No. 63230-733.601days, about 15 days, about 16 days, about 17 days, about 18 days, about 19 days, about 20 days, about 21 days, about 22 days, about 23 days, about 24 days, about 25 days, about 26 days, about 27 days, about 28 days, about 29 days, about 30 days, about 31 days, about 1 month, about 2 months, about 3 months, about 4 months, about 5 months, about 6 months, about 7 months, about 8 months, about 9 months, about 10 months, about 11 months, or at least about 12 months. In some embodiments, the period of time comprises about 1 day to about 6 months, about 2 days to about 5 months, about 3 days to about 4 months, about 4 days to about 3 months, about 5 days to about 2 months, about 6 days to about 1 months, about 7 days to about 31 days, about 8 days to about 30 days, about 9 days to about 29 days, about 10 days to about 28 days, about 11 days to about 27 days, about 12 days to about 26 days, about 13 days to about 25 days, about 14 days to about 24 days, about 15 days to about 23 days, about 16 days to about 22 days, about 17 days to about 21 days, or about 18 days to about 20 days.

[0115] In some embodiments, the composition is coated over a total surface of the scalp of the subject. In some embodiments, the composition is coated over about 5% to about 100% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over about 5% to about 100%, about 5% to about 95%, about 5% to about 90%, about 5% to about 85%, about 5% to about 80%, about 5% to about 75%, about 5% to about 70%, about 5% to about 65%, about 5% to about 60%, about 5% to about 55%, about 5% to about 50%, about 5% to about 45%, about 5% to about 40%, about 5% to about 35%, about 5% to about 30%, about 5% to about 25%, about 5% to about 20%, about 10% to about 100%, about 10% to about 95%, about 10% to about 90%, about 10% to about 85%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 10% to about 20%, about 15% to about 100%, about 15% to about 95%, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 15% to about 25%, about 15% to about 20%, about 20% to about 100%, about 20% to about 95%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%,WSGR Docket No. 63230-733.601about 20% to about 35%, about 20% to about 30%, about 20% to about 25%, about 25% to about 100%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 25% to about 35%, about 25% to about 30%, about 30% to about 100%, about 30% to about 95%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 30% to about 45%, about 30% to about 40%, or about 30% to about 35% of the total surface of the scalp of the subject.

[0116] In some embodiments, the composition is coated over at least about 10% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over at least at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 100% of the total surface of the scalp of the subject.

[0117] In some embodiments, the composition is substantially heterogeneously coated over the surface of the scalp of the subject. In some embodiments, the composition is substantially uniformly coated over the surface of the scalp of the subject.

[0118] In some embodiments, the composition is coated over at least about 10% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 100% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over about 10% to about 100%, about 10% to about 95%, about 10% to about 90%, about 10% to about 85%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 10% to about 20%, about 10% to about 15%, about 15% to about 100%, about 15% to about 95%, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% toWSGR Docket No. 63230-733.601about 30%, about 15% to about 25%, about 15% to about 20%, about 20% to about 100%, about 20% to about 95%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, about 20% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 20% to about 35%, about 20% to about 30%, about 20% to about 25%, about 25% to about 100%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 25% to about 35%, about 25% to about 30%, about 30% to about 100%, about 30% to about 95%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 30% to about 45%, about 30% to about 40%, or about 30% to about 35% of the total surface of the scalp of the subject. In some embodiments, the composition is coated over about 10% to about 95% of the total surface of the scalp of the subject.

[0119] In some embodiments, applying the composition to the scalp comprises covering at least about 10% to about 100% of the total surface area of the scalp. In some embodiments, the composition is covered over at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 100% of the target surface area of the scalp. In some embodiments, the composition is covered over about 10% to about 100%, about 10% to about 95%, about 10% to about 90%, about 10% to about 85%, about 10% to about 80%, about 10% to about 75%, about 10% to about 70%, about 10% to about 65%, about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 10% to about 25%, about 10% to about 20%, about 10% to about 15%, about 15% to about 100%, about 15% to about 95%, about 15% to about 90%, about 15% to about 85%, about 15% to about 80%, about 15% to about 75%, about 15% to about 70%, about 15% to about 65%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 15% to about 25%, about 15% to about 20%, about 20% to about 100%, about 20% to about 95%, about 20% to about 90%, about 20% to about 85%, about 20% to about 80%, about 20% to about 75%, about 20% to about 70%, aboutWSGR Docket No. 63230-733.60120% to about 65%, about 20% to about 60%, about 20% to about 55%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 20% to about 35%, about 20% to about 30%, about 20% to about 25%, about 25% to about 100%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 75%, about 25% to about 70%, about 25% to about 65%, about 25% to about 60%, about 25% to about 55%, about 25% to about 50%, about 25% to about 45%, about 25% to about 40%, about 25% to about 35%, about 25% to about 30%, about 30% to about 100%, about 30% to about 95%, about 30% to about 90%, about 30% to about 85%, about 30% to about 80%, about 30% to about 75%, about 30% to about 70%, about 30% to about 65%, about 30% to about 60%, about 30% to about 55%, about 30% to about 50%, about 30% to about 45%, about 30% to about 40%, or about 30% to about 35% of the total surface of the scalp of the subject. In some embodiments, the composition is covered over about 10% to about 95% of the target surface area of the scalp. In some embodiments, the composition is covered over about 10% to about 100% of the target surface area of the scalp. In some embodiments, the target surface area of the scalp is the surface area of the scalp on the crown of a head.

[0120] In some embodiments, the method comprises applying a compound or polymer as described herein. In some embodiments, the compound or polymer thereof absorbs light having a wavelength of about 320 nm to about 400 nm. In some embodiments, the compound or polymer thereof absorbs light having a wavelength of about 280 nm to about 320 nm. In some embodiments, the compound or polymer thereof absorbs light having a wavelength of about 280 nm to about 400 nm. In some embodiments, the compound or polymer thereof has a molar absorptivity of about 0 mM-1cm-1over a wavelength of about 400 to about 800 nm. In some embodiments, the absorbance of the compound or polymer thereof is determined with UV-Vis spectroscopy. In some embodiments, the molar absorptivity is determined with UV-Vis spectroscopy.

[0121] In some aspects, provided herein are methods comprising administering a polymer of the compound. The polymer of the compound is represented by the structure of Formula (I):WSGR Docket No. 63230-733.601Formula (I);or a salt thereof, wherein:is selected from:each R1is independently selected from hydrogen, Ci-6 alkyl, -C(O)R23, and - C(O)OR23;each R2is independently selected from hydrogen, halogen, Ci-6 alkyl, -Si(R20)3, and - B(R21)2;each R3is independently selected from hydrogen and Ci-6 alkyl;each R4is independently selected from hydrogen and Ci-6 alkyl;each R5and R6are independently selected from hydrogen, -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from halogen and Ci-io alkyl;R7is selected from hydrogen, halogen, Ci-6 alkyl, and -B(R21)2;each R20is independently selected from Ci-6 alkyl;each R21is independently selected from -OR22;each R22is independently selected from hydrogen and Ci-6 alkyl; ortwo R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl;each R23is independently selected from Ci-6 alkyl which is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, - NO2, -NH2, -N(CI-6 alkyl)2, Ci-6 alkyl, -Ci-6 haloalkyl, and -O-Ci-6 alkyl; and m is selected from 1 to 20.WSGR Docket No. 63230-733.601OR5I j pZ \ »3In some embodiments,— ' is R. In some embodiments,is. OR5R4R3. In some embodiments, each R1is independently selected from hydrogen, -C(O)R23, and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen. In some embodiments, each R2is independently selected from hydrogen, Ci-6 alkyl, -Si(R20)3, and -B(R21)2. In some embodiments, each R2is independently selected from hydrogen, -Si(R20)3, and -B(R21)2. In some embodiments, each R2is independently selected from hydrogen, -Si(Me)3, and -Bpin. In some embodiments, each R3is independently selected from hydrogen and Ci-4 alkyl. In some embodiments, each R3is independently selected from hydrogen. In some embodiments, each R4is selected from hydrogen and Ci-4 alkyl. In some embodiments, each R4is selected from hydrogen. In some embodiments, R7is selected from hydrogen, halogen, and -B(R21)2. In some embodiments, R7is selected from hydrogen, bromo, iodo, and -B(R21)2. In some embodiments, R7is selected from hydrogen, iodo, -B(R21)2. In some embodiments, each R5and R6are independently selected from -Si(R20)3 and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl. In some embodiments, each R5and R6are independently selected from -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally and independently substituted with one or more Ci-4 alkyl. In some embodiments, each R20is independently selected from Ci-4 alkyl. In some embodiments, each R22is independently selected from hydrogen; or two R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl. In some embodiments, two R22on different O atoms are taken together with the O atom toWSGR Docket No. 63230-733.601which each R22is attached to form a heterocycle, which is optionally substituted with one or more substituents independently selected from Ci-6 alkyl.

[0122] In some embodiments, Formula (I) is represented by the structure of Formula (I-A):Formula (I-A);or a salt thereof. In some embodiments, Formula (I) is represented by the structure of Formula (I-B):R6°V_ / R7R5O-V V, R1OR6R4%. OR5R3IfRI^ R'N04R2R3Formula (I-B);or a salt thereof. In some embodiments, Formula (I) is represented by the structure of Formula (I-C):Formula (I-C);or a salt thereof, wherein: m is selected from 1 to 20. In some embodiments, each R1is independently selected from hydrogen, -C(O)R23, and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen and -C(O)OR23. In some embodiments, each R1is independently selected from hydrogen. In some embodiments, each R2is independently selected from hydrogen, Ci-6 alkyl, -Si(R20)3, and -B(R21)2. In some embodiments, each R2is independently selected from hydrogen, -Si(R20)3, and -B(R21)2. InWSGR Docket No. 63230-733.601some embodiments, each R2is independently selected from hydrogen, -Si(Me)3, and -Bpin. In some embodiments, each R3is independently selected from hydrogen and C1-4 alkyl. In some embodiments, each R3is independently selected from hydrogen. In some embodiments, each R4is selected from hydrogen and Ci-4 alkyl. In some embodiments, each R4is selected from hydrogen. In some embodiments, R7is selected from hydrogen, halogen, and -B(R21)2. In some embodiments, R7is selected from hydrogen, bromo, iodo, and -B(R21)2. In some embodiments, R7is selected from hydrogen, iodo, -B(R21)2. In some embodiments, each R5and R6are independently selected from -Si(R20)3 and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl. In some embodiments, each R5and R6are independently selected from -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally and independently substituted with one or more Ci-4 alkyl. In some embodiments, each R20is independently selected from Ci-4 alkyl. In some embodiments, each R22is independently selected from hydrogen; or two R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl. In some embodiments, two R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle, which is optionally substituted with one or more substituents independently selected from Ci-6 alkyl. In some embodiments, the polymer of the compound is selected from:WSGR Docket No. 63230-733.601WSGR Docket No. 63230-733.601EXAMPLESExample 1: Protection of Hair from Damage by UV Light

[0123] Tresses of hair with (samples) and without (control) the composition described herein were exposed to UV light at an intensity equivalent to at least about 2 hours, about 3 hours, about 6 hours, about 12 hours, about 1 day, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 7 days, about 2 weeks, about 1 month, about 2 months, and about 6 months were prepared.

[0124] UV-Vis spectra of the control and sample are taken before and after application of the composition. Afterwards the hair is exposed to UV light at the described times, and UV-Vis spectra are collected before and after exposure to UV light. Prior to each UV-Vis measurement, hair is washed with shampoo to remove any excess composition coated thereon.Example 2: Elasticity and Hair StrengthWSGR Docket No. 63230-733.601

[0125] Tresses of hair with (samples) and without (control) the composition described herein were exposed to UV light at an intensity equivalent to at least about 2 hours, about 3 hours, about 6 hours, about 12 hours, about 1 day, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 7 days, about 2 weeks, about 1 month, about 2 months, and about 6 months are prepared.

[0126] With a tensiometer, the Young’s Modulus and break stress of the control and samples are taken before and after application of the composition. Afterwards the hair is exposed to UV light at the described times, and Young’s Moduli and break stresses of each of the samples and control are collected before and after exposure to UV light. Prior to each tensiometer measurement, hair is washed with shampoo to remove any excess composition coated thereon.Example 3: Color Fade Assay of Sample Hair Tresses

[0127] Sample Preparation, tresses are soaked in hard water (sample 1), and tresses are bleached and soaked in hard water (sample 1). Each of samples 1 and 2 are sampled with the same treatment protocols for comparison. A portion of tresses from sample 1 (samples) and a portion of tresses from sample 2 (sample 2’) were taken and exposed under a UV at an intensity equivalent to at least about 2 hours, about 3 hours, about 6 hours, about 12 hours, about 1 day, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 7 days, about 2 weeks, about 1 month, about 2 months, and about 6 months as controls (i.e., UV exposure without composition).

[0128] Bleaching treatment protocol (samples): A mixture of lightener and developer is prepared. The mixture is added to each hair tress using a brush (5g on each side) and massage thoroughly into tress. Position tresses on a hot plate with temperature maintained at 27 °C or room temperature (RT). The bleach is allowed to process on the hair for 40 minutes at 27 °C or RT. The tresses are turned over after 20 min (halfway) and massage to allow for even coloring. The tresses are washed under an Intellifaucet for 2 minutes (or until water runs clear) at 40°C and 1.0 GPM flow rate. The tresses are rested for at least 12 hours.

[0129] Coloring treatment protocol', the tresses are color treated with a commercial coloring agent. Color components according to the manufacturer’s instructions and mix thoroughly. 10 grams of the mixture is applied to each hair tress using a brush (5g on each side) and are massaged thoroughly into the tresses. Tresses were positioned on a hot plate with temperature maintained at 27 °C or RT. The color was allowed to process on the hair for 20 minutes at 27 °C or RT. Tresses were turned over after 10 min (halfway) and massage toWSGR Docket No. 63230-733.601allow for even coloring. Tresses were rinsed out under an Intellifaucet for 2 minutes (or until water runs clear) at 40°C and 1.0 GPM flow rate. Tresses were allowed to rest for at least 12 hours prior to taking post color readings.

[0130] A total of four test groups (4 cells) are tested: Test group 1 (Cell 1) is treated under the UV exposure conditions above; Test group 2 (Cell 2) is treated with a composition described herein after bleaching, then the tresses are treated under the UV exposure conditions above; Test group 3 (Cell 3) is treated with bleach then treated under the UV exposure conditions above; and Test group 4 (Cell 4) is treated with bleach, color (dye), then the composition and subsequently treated under the UV exposure conditions above. All tresses in each of Cells 1-4 are exposed to UV light for a period of time as described above.

[0131] Each treatment is performed using an Intellifaucet set at approximately 40°C and 1.0 GPM flow rate. Photos of all tresses are taken three times including before UV exposure, after UV exposure, and after bleach / color application.

[0132] Color Fade Testing-. All the dyed hair tresses are labeled to allow for identification. Baseline L, a, and b measurements are taken using a Hunter Lab UltraScan VIS colorimeter to characterize the initial color of hair. Technical hair color is often quantified using the CIELAB L, a, b system (parameters further explained in the appendix). That color is represented in a 3-dimensional matrix where “L” refers to the lightness on a scale of 0 to 100, “a” denotes the red-green color range (positive value denotes higher red) and “b” represents the yellow-blue color range (positive value denotes higher yellow). Generally, changes in the color of the tress are evaluated by calculating the difference in these parameters relative to a reference state (i.e., AL*, Aa*, and Ab*). In addition, it is common to report an overall color change, AE. That is,ΔE = √[ΔL*2 + Δa*2 + Δb*2]

[0133] Ten (10) color measurements are performed each tress. Ten (10) tresses per treatment provided appropriate statistical rigor. Box and whisker plot is generated using Statistica™, while JMPTM analytical software is used to calculate the statistics (student’s t-test at 95% confidence level).Example 4: DSC Assay of Sample Hair Tresses

[0134] The efficacy of the compounds of the instant disclosure in preventing UV damage to bleached and dyed hair were assayed using differential scanning calorimetry (DSC). DSC may be used on wet hair samples between 50°C and 200°C to detect changes in thermalWSGR Docket No. 63230-733.601properties including protein denaturation. Keratin undergoes detectable transformations at various temperatures, which may depend on treatments that the hair has been subjected to. For example, bleaching decreases the transition peak temperature of hair. The differences in transition peak temperatures may be due to changes in keratin structure, cysteine bond arrangements, or strongly bound water in the keratin. Thus, DSC can provide insights into how a treatment may affect structural changes in hair keratin.Hair Treatment

[0135] Hair tresses (1.5 g, 6” long, 1” wide) were bleached and dyed according to known methods. 3 replicates were prepared for each experimental group. The following treatments were applied to the hair tresses: negative control, 1% Compound 3, 1% Compound 4, or 1% Compound 5. The treatment was applied to hair according to the following protocol. First, the tresses of hair were weighed after washing. 5 mL of each solution was added to weigh boats and 1.5 g of hair were placed in each solution. The hair was massaged in the solution for 30 seconds. The hair was gently squeezed, weighed, and the mass of the solution left on the hair was recorded. The hair was then combed on either side.DSC Measurement

[0136] An initial measurement was performed for the denaturation temperature of each hair tress. The tresses were bound to make them suitable for UV exposure, after which initial treatment was applied. The hair tresses were blow-dried and exposed to UV for 2 hours (0.67 W / m2 to mimic 4.5x exaggerated conditions, 60% RH). A second measurement of the denaturation temperature of each hair tress was performed at the 2-hour time point. Following the second measurement, the hair tresses were washed with 15% SLES according to the following protocol: hair was wetted for 30 seconds, shampoo was applied to the hair at 10% dosage, hair was massaged for 30 seconds, and hair was rinsed for 30 seconds. The treatments were reapplied to each hair tress (reapplication 1). The hair tresses were blow-dried and exposed to UV for a further 2 hours (0.67 W / m2 to mimic 4.5x exaggerated conditions, 60% RH). A third measurement of the denaturation temperature of each hair tress was performed at the 4-hour time point. Following the third measurement, the hair was washed according to the aforementioned protocol. The treatments were reapplied to each hair tress (reapplication 2). The hair tresses were blow-dried and exposed to UV for a further 2 hours (0.67 W / m2 to mimic 4.5x exaggerated conditions, 60% RH). A final measurement of the denaturation temperature of each hair tress was performed at the 6-hour time point.

[0137] Statistical significance was calculated using JMP analytical software version 17.0. A one-way analysis of the data was performed on a distribution of Y (Td or Ta) for each XWSGR Docket No. 63230-733.601(Treatment). The standard student’s-ttest at 95% confidence level, and a = 0.05 was used to perform the analysis. If the p-value was less than a (0.05), treatments were considered to be statistically significant.Results

[0138] Each hair tress was compared to their respective individual controls after UV exposure. The results showed a statistically significant decrease in crosslinking density of the bleached and dyed hair negative control after 2 hours of UV treatment (Table 1). In contrast, there were no statistically significant differences between (i) 1% Compound 3 at 0 hours and 2 hours UV, (ii) 1% Compound 4 at 0 hours and 2 hours UV, or (iii) 1% Compound 5 at 0 hours and 2 hours UV (Table 1).Table 1. JMP analysis of Td after 2 hours of UV treatment, °C. ct=0.05 _Std Err Differenc Treatment N Mean Std Dev Mean e Negative Control - O hUV 3 147.4 0.6 0.4 A1% Compound 3 - 2 h UV 3 146.9 1.0 0.6 A B1% Compound 5 - 0 h UV 3 146.7 1.1 0.6 A B1% Compound 4 - 0 h UV 3 146.7 0.6 0.3 A B1% Compound 4 - 2 h UV 3 146.5 0.8 0.5 A B1% Compound 3 - 0 h UV 3 146.4 0.5 0.3 A B C 1% Compound 5 - 2 h UV 3 145.7 0.8 0.4 B C Negative Control - 2 hUV 3 145.1 0.9 0.5 C Eevels not connected by the same letter are significantly different.

[0139] The results showed a statistically significant decrease in crosslinking density of the negative control after 4 hours of UV treatment (Table 2). The denaturation temperature of 1% Compound 3 at 4 hours UV was statistically lower than its respective control. However, this difference was less than that observed between the negative control at 0 hours and 4 hours of UV treatment (Table 2), which is indicative of UV protection. In contrast, there were no statistically significant differences for (i) 1% Compound 4 between 0 hours and 4 hours UV, or (ii) 1% Compound 5 between 0 hours and 4 hours UV (Table 2) which is indicative of UV protection.Tab e 2. JMP analysis of Td after 4 hours of UV treatment, °C. a =0.05Std ErrTreatment N Mean Std Dev Mean Difl erence 1% Compound 5 - 4 h UV 3 147.8 0.4 0.2 ANegative Control - O h UV 3 147.4 0.6 0.4 A B1% Compound 4 - 4 h UV 3 147.0 1.1 0.6 A BWSGR Docket No. 63230-733.6011% Compound 5 - 0 h UV 3 146.7 1.1 0.6 A B1% Compound 4 - 0 h UV 3 146.7 0.6 0.3 A B1% Compound 3 - 0 h UV 3 146.4 0.5 0.3 B1% Compound 3 - 4 h UV 3 145.1 0.7 0.4 CNegative Control - 4 h UV 3 142.9 0.9 0.5 D Levels not connected by the same letter are significantly different.

[0140] The results showed a statistically significant decrease in crosslinking density of the negative control after 6 hours of UV treatment (Table 3). There were no statistically significant differences between (i) 1% Compound 3 at 0 hours and 6 hours UV, (ii) 1% Compound 4 at 0 hours and 6 hours UV, or (iii) 1% Compound 5 at 0 hours and 6 hours UV (Table 3), which is indicative of UV protection.Table 3. JMP analysis of Td after 6 hours of UV treatment, °C. a=0.05Std ErrTreatment N Mean Std Dev Mean Difference 1% Compound 5 - 6 h UV 3 147.7 0.1 0.1 ANegative Control - O h UV 3 147.4 0.6 0.4 A B1% Compound 5 - 0 h UV 3 146.7 1.1 0.6 A B C1% Compound 4 - 0 h UV 3 146.7 0.6 0.3 B C1% Compound 3 - 0 h UV 3 146.4 0.5 0.3 B c1% Compound 4 - 6 h UV 3 146.0 0.3 0.2 c1% Compound 3 - 6 h UV 3 145.7 0.8 0.5 cNegative Control - 6 h UV 3 140.7 0.2 0.1 D Levels not connected by the same letter are significantly different.Conclusion

[0141] These findings indicated that 1% Compound 3, 1% Compound 4, and 1% Compound 5 are effective in mitigating UV-induced damage to hair during 2, 4, and 6 hours of accelerated UV exposure.NUMBERED EMBODIMENTS

[0142] Embodiment 1. A method of protecting hair of a subject from damage by ultraviolet (UV) light, the method comprising: applying a composition to the hair the subject, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601combination of two or more thereof.

[0143] Embodiment 2. The method of Embodiment 1, wherein the polymer of the compound is represented by the structure of Formula (I):or a salt thereof, wherein:is selected from:each R1is independently selected from hydrogen, Ci-6 alkyl, -C(O)R23, and - C(O)OR23;each R2is independently selected from hydrogen, halogen, Ci-6 alkyl, -Si(R20)3, and - B(R21)2;each R3is independently selected from hydrogen and Ci-6 alkyl;each R4is independently selected from hydrogen and Ci-6 alkyl;WSGR Docket No. 63230-733.601each R5and R6are independently selected from hydrogen, -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from halogen and Ci-io alkyl;R7is selected from hydrogen, halogen, Ci-6 alkyl, and -B(R21)2;each R20is independently selected from Ci-6 alkyl;each R21is independently selected from -OR22;each R22is independently selected from hydrogen and Ci-6 alkyl; ortwo R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl;each R23is independently selected from Ci-6 alkyl which is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, - NO2, -NH2, -N(CI-6 alkyl)2, C1-6 alkyl, -Ci-ehaloalkyl, and -O-C1-6 alkyl; and m is selected from 1 to 20.( A )

[0144] Embodiment 3. The method of Embodiment 2, wherein ' is1'NR2 XR3( A )

[0145] Embodiment 4. The method of Embodiment 2, wherein isz— XI—OR5R6O

[0146] Embodiment 5. The method of any one of Embodiments 2 - 4, wherein each R1is independently selected from hydrogen, -C(O)R23, and -C(O)OR23.

[0147] Embodiment 6. The method of any one of Embodiments 2 - 5, wherein each R1is independently selected from hydrogen and -C(O)OR23.WSGR Docket No. 63230-733.601

[0148] Embodiment 7. The method of any one of Embodiments 2 - 6, wherein each R1is independently selected from hydrogen.

[0149] Embodiment 8. The method of any one of Embodiments 2 - 7, wherein each R2is independently selected from hydrogen, Ci-6 alkyl, -Si(R20)3, and -B(R21)2.

[0150] Embodiment 9. The method of any one of Embodiments 2 - 8, wherein each R2is independently selected from hydrogen, -Si(R20)3, and -B(R21)2.

[0151] Embodiment 10. The method of any one of Embodiments 2 - 9, wherein each R2is independently selected from hydrogen, -Si(Me)3, and -Bpin.

[0152] Embodiment 11. The method of any one of Embodiments 2 - 10, wherein each R3is independently selected from hydrogen and Ci-4 alkyl.

[0153] Embodiment 12. The method of any one of Embodiments 2 - 11, wherein each R3is independently selected from hydrogen.

[0154] Embodiment 13. The method of any one of Embodiments 2 - 12, wherein each R4is selected from hydrogen and Ci-4 alkyl.

[0155] Embodiment 14. The method of any one of Embodiments 2 - 13, wherein each R4is selected from hydrogen.

[0156] Embodiment 15. The method of any one of Embodiments 2 - 14, wherein R7is selected from hydrogen, halogen, and -B(R21)2.

[0157] Embodiment 16. The method of any one of Embodiments 2 - 15, wherein R7is selected from hydrogen, bromo, iodo, and -B(R21)2.

[0158] Embodiment 17. The method of any one of Embodiments 2 - 16, wherein R7is selected from hydrogen, iodo, -B(R21)2.

[0159] Embodiment 18. The method of any one of Embodiments 2 - 17, wherein each R5and R6are independently selected from -Si(R20)3 and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl.

[0160] Embodiment 19. The method of any one of Embodiments 2 - 18, wherein each R5and R6are independently selected from -Si(R20)3, and Ci-6 alkyl; or one R5and one R6are taken together to form a heterocycle which is optionally and independently substituted with one or more Ci-4 alkyl.

[0161] Embodiment 20. The method of any one of Embodiments 2 - 19, wherein each R20is independently selected from Ci-4 alkyl.

[0162] Embodiment 21. The method of any one of Embodiments 2 - 20, wherein each R22is independently selected from hydrogen; or two R22on different O atoms are takenWSGR Docket No. 63230-733.601together with the O atom to which each R22is attached to form a heterocycle which is optionally substituted with one or more substituents independently selected from Ci-io alkyl.

[0163] Embodiment 22. The method of any one of Embodiments 2 - 21, wherein two R22on different O atoms are taken together with the O atom to which each R22is attached to form a heterocycle, which is optionally substituted with one or more substituents independently selected from Ci-6 alkyl.

[0164] Embodiment 23. The method of any one of Embodiments 2 - 22, wherein Formula (I) is represented by the structure of Formula (I -A):or a salt thereof.

[0165] Embodiment 24. The method of any one of Embodiments 2 - 23, wherein Formula (I) is represented by the structure of Formula (I-B):or a salt thereof.

[0166] Embodiment 25. The method of any one of Embodiments 2 - 24, wherein Formula (I) is represented by the structure of Formula (I-C):Formula (I-C);WSGR Docket No. 63230-733.601or a salt thereof, wherein:m is selected from 1 to 20.

[0167] Embodiment 26. The method of any one of Embodiments 2-25, wherein the compound is selected from:WSGR Docket No. 63230-733.601WSGR Docket No. 63230-733.601

Claims

1. WSGR Docket No. 63230-733.601CLAIMSWhat is claimed is:

1. A method of protecting hair of a subject from damage by ultraviolet (UV) light, the method comprising:applying a composition to the hair the subject, the composition comprising a compound having the structure:combination of two or more thereof.

2. The method of claim 1, wherein the damage is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, Fourier-transform (FTIR) spectroscopy, Raman spectroscopy, or a combination thereof.

3. A method of preventing discoloration of hair of a subject, the method comprising:applying a composition to the hair of the subject, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601combination of two or more thereof.

4. The method of claim 3, wherein the damage is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

5. The method of claim 3 or 4, wherein the hair exhibits a hair color loss (ΔE) of less than about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay.

6. A method of preventing loss of color from hair, the method comprising:applying a composition to the hair, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601combination of two or more thereof.

7. The method of claim 6, wherein the loss is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

8. A method of preventing breakage of hair, the method comprising:applying a composition to the hair, the composition comprising a compound having the structure:combination of two or more thereof.WSGR Docket No. 63230-733.6019. The method of claim 8, wherein preventing breakage of the hair comprises reducing protein degradation.

10. The method of claim 9, wherein reducing protein degradation comprises reducing oxidation of tryptophan or tyrosine residues in a hair protein of the hair as compared to oxidation of tryptophan or tyrosine residues in the hair protein of hair not applied with the composition.

11. A method of maintaining strength of hair, the method comprising:applying a composition to the hair, the composition comprising a compound having the structure:or a combination of two or more thereof.

12. The method of claim 11, wherein the elasticity of the hair is measured by a Young ’s Modulus of hair.

13. The method of claim 11 or claim 12, wherein a strength of hair is determined by measuring a break stress of hair, and wherein the strength of hair applied with the composition is greater than a strength of hair not applied with the composition.

14. A method of reducing fragility of hair, the method comprising:applying a composition to the hair, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601combination of two or more thereof,wherein the fragility of the hair is reduced as compared to a fragility of hair not applied with the composition.

15. The method of claim 14, wherein reducing fragility of hair comprises reducing protein degradation of hair, wherein reducing protein degradation comprises reducing oxidation of tryptophan or tyrosine residues in a hair protein of the hair as compared to oxidation of tryptophan or tyrosine residues in the hair protein of hair not applied with the composition.

16. The method of claim 14 or claim 15, wherein the fragility of the hair is determined by measuring a Young’s Modulus of hair.

17. The method of any one of claims 14-16, wherein the Young’s Modulus of hair applied with the composition is at least about 3,000 Pa, about 3,200 Pa, about 3,400 Pa, about 3,600 Pa, about 3,800 Pa, about 4,000 Pa, about 4,200 Pa, about 4,400 Pa, about 4,600 Pa, about 4,800 Pa, about 5,000 Pa, about 5,200 Pa, about 5,400 Pa, about 5,600 Pa, about 5,800 Pa, about 6,000 Pa, about 6,200 Pa, about 6,400 Pa, about 6,600 Pa, about 6,800 Pa, or about 7,000 Pa.

18. The method of any one of claims 14-17, wherein the Young’s Modulus of hair applied with the composition has a Young’s Modulus about 2-fold, about 3-fold, about 4-fold,WSGR Docket No. 63230-733.601or about 5-fold higher than a Young’s Modulus of hair not applied with the composition.

19. The method of claim 13, wherein the break stress of hair is about 200 Pa to about 500 Pa.

20. A method of shielding a hair of a subject from ultraviolet (UV) light, the method comprising:applying a composition to the hair of the subject, the composition comprising a compound having the structure:combination of two or more thereof,wherein the compound absorbs UV light having a wavelength of about 280 nm to about 400 nm.

21. The method of claim 20, wherein the shielding is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, UV absorbance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

22. A method of preventing or minimizing penetration of UV light into a hair cortex of a subject, the method comprising:applying a composition to the hair, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601combination of two or more thereof.

23. The method of claim 22, wherein the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

24. A method of preventing or minimizing formation of free radicals in a hair of a subject, the method comprising:applying a composition to the hair of the subject, the composition comprising a compound having the structure:combination of two or more thereof.WSGR Docket No. 63230-733.60125. The method of claim 24, wherein the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

26. A method of retaining the color of hair, the method comprising:applying a composition to the hair, the composition comprising a compound having the structure:NH O Oor a polymer thereof, or a combination of two or more thereof,wherein at least about 60% of the hair color is retained in hair.

27. The method of claim 26, wherein the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

28. The method of claim 27, wherein the hair exhibits a hair color loss (ΔE) of less than about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, about 2, or about 1, wherein the hair color loss is determined by a color fade assay.WSGR Docket No. 63230-733.60129. A method of coating a hair on a scalp of a subject, the method comprising:applying a composition to the hair on the scalp of the subject, the composition comprising a compound having the structure:combination of two or more thereof,wherein the composition is coated over a surface of the hair of the subject.

30. The method of claim 29, wherein the coating is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, or a combination thereof.

31. The method of claim 29 or claim 30, wherein the composition is coated over about 5% to about 100% of the total surface of the hair on the scalp of the subject.

32. The method of any one of claims 29-31, wherein the composition is coated over at least about 10% of the total surface of the hair on the scalp of the subject.

33. The method of any one of claims 29-32, wherein the composition is coated over the total surface of the hair on the scalp of the subject.

34. The method of any one of claims 29-33, wherein the composition is coated over about 10% to about 95% of the total surface of the hair on the scalp of the subject.WSGR Docket No. 63230-733.60135. The method of any one of claims 29-34, wherein the composition is heterogeneously coated over the surface of the hair on the scalp of the subject.

36. The method of any one of claims 29-35, wherein the composition is uniformly coated over the surface of the hair on the scalp of the subject.

37. The method of any one of claims 1-36, wherein applying the composition to the hair comprises covering at least about 10% to about 100% of the total surface area of the hair.

38. The method of any one of claims 1-37, wherein applying the composition to the hair comprises covering at least about 10% to about 100% of a target surface area of the hair, wherein the target surface area of the hair is the surface area of the hair on the crown of a head.

39. The method of any one of claims 1-38, wherein after applying the composition to the hair, about 1% to about 20% of UV light is permitted into the cortex of the hair.

40. A method of protecting scalp of a subject from damage by ultraviolet (UV) light, the method comprising:applying a composition to the scalp the subject, the composition comprising a compound having the structure:combination of two or more thereof.WSGR Docket No. 63230-733.60141. The method of claim 40, wherein the damage is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, transepidermal water loss (TEWL) measurements, corneometry, or a combination thereof.

42. A method of shielding a scalp of a subject from ultraviolet (UV) light, the method comprising:applying a composition to the scalp of the subject, the composition comprising a compound having the structure:combination of two or more thereof,wherein the compound absorbs UV light having a wavelength of about 280 nm to about 400 nm.

43. The method of claim 42, wherein the shielding is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine-content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, transepidermal water loss (TEWL) measurements, corneometry, or a combination thereof.WSGR Docket No. 63230-733.60144. A method of preventing or minimizing penetration of UV light into a scalp of a subject, the method comprising:applying a composition to the scalp, the composition comprising a compound having the structure:combination of two or more thereof.

45. The method of claim 44, wherein the preventing or minimizing penetration of UV light into hair is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, transepidermal water loss (TEWL) measurements, corneometry, or a combination thereof.

46. A method of preventing or minimizing formation of free radicals in a scalp of a subject, the method comprising:applying a composition to the scalp of the subject, the composition comprising a compound having the structure:WSGR Docket No. 63230-733.601combination of two or more thereof.

47. The method of claim 46, wherein the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, transepidermal water loss (TEWL) measurements, corneometry, or a combination thereof.

48. A method of coating a scalp of a subject, the method comprising:applying a composition to the scalp of the subject, the composition comprising a compound having the structure:combination of two or more thereof,WSGR Docket No. 63230-733.601wherein the composition is coated over a surface of the scalp of the subject.

49. The method of claim 48, wherein the preventing or minimizing formation of free radicals is determined by differential scanning calorimetry (DSC), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a color fade assay, cystine -content assay, transmission electron microscopy (TEM), scanning electron microscopy (SEM), reflectance spectroscopy, FTIR spectroscopy, Raman spectroscopy, transepidermal water loss (TEWL) measurements, corneometry, or a combination thereof.

50. The method of claim 48 or claim 49, wherein the composition is coated over about 5% to about 100% of the total surface of the scalp of the subject.

51. The method of any one of claims 48-50, wherein the composition is coated over at least about 10% of the total surface of the scalp of the subject.

52. The method of any one of claims 48-51, wherein the composition is coated over the total surface of the scalp of the subject.

53. The method of any one of claims 48-52, wherein the composition is coated over about 10% to about 95% of the total surface of the scalp of the subject.

54. The method of any one of claims 48-53, wherein the composition is heterogeneously coated over the surface on the scalp of the subject.

55. The method of any one of claims 48-54, wherein the composition is uniformly coated over the surface on the scalp of the subject.

56. The method of any one of claims 40-55, wherein applying the composition to the scalp comprises covering at least about 10% to about 100% of the total surface area of the scalp.

57. The method of any one of claims 40-56, wherein applying the composition to the scalp comprises covering at least about 10% to about 100% of a target surface area ofWSGR Docket No. 63230-733.601the scalp, wherein the target surface area of the scalp is the surface area of the scalp on the crown of a head.

58. The method of any one of claims 40-57, wherein after applying the composition to the scalp, about 1% to about 20% of UV light is permitted through the scalp.

59. The method of any one of claims 40-58, wherein the compound or polymer thereof absorbs light having a wavelength of about 320 nm to about 400 nm.

60. The method of any one of claims 40-59, wherein the compound or polymer thereof absorbs light having a wavelength of about 280 nm to about 320 nm.

61. The method of any one of claims 40-60, wherein the compound or polymer thereof absorbs light having a wavelength of about 280 nm to about 400 nm.

62. The method of any one of claims 40-61, wherein the compound or polymer thereof has a molar absorptivity of about 0 mM-1cm-1over a wavelength of about 400 to about 800 nm.

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