Ação da luz visível na oxidação da melanina e no descolorimento do cabelo / Action of the visible on the melanin oxidation and hair discoloration

O dano capilar causado pelo descolorimento oxidativo é muito intenso, sendo que dois fatores são responsáveis por essa ação: primeiro, a ação direta e danosa do oxidante em diversas estruturas capilares e segundo, o dano oxidativo primário facilita o dano causado por outros agentes físicos (luz, temperatura) e químicos (tensoativos), que comumente tem ação nos cabelos. Desenvolver conceitos e tecnologias que possam tornar o oxidante específico para a melanina e por conseguinte efetuando o descolorimento sem causar danos ao fio é extremamente desejável. Neste trabalho buscaremos entender de que forma a luz visível pode aumentar a ação do oxidante sem danificar o fio colateralmente. O objetivo principal deste trabalho é demonstrar que é possível utilizar a luz visível, que é absorvida pela melanina, para tornar esse pigmento mais suscetível ao agente oxidante e desta forma, permitir que o descolorimento seja realizado com concentrações pequenas de oxidante. Também almejamos desenvolver métodos de análises por microscopia ótica de fluorescência e de reflexão para mensurar o dano nas estruturas dos fios processados com oxidante e na presença ou ausência da luz

The capillary damage caused by oxidative discoloration is very intense, and two factors are responsible for this action: first, the direct and harmful action of the oxidant on several capillary structures and second, the primary oxidative damage facilitates the damage caused by other physical agents (light, temperature) and chemicals (surfactants), which commonly have action on the hair. Developing concepts and technologies that can make the oxidant specific to melanin and therefore discoloring without causing damage to the hair is extremely desirable. In this work we will try to understand how visible light can increase the oxidant's action without damaging the wire collaterally. The main objective of this work is to demonstrate that it is possible to use visible light, which is absorbed by melanin, to make this pigment more susceptible to the oxidizing agent and, thus, to allow the discoloration to be carried out with small concentrations of oxidizer. We also aim to develop methods of analysis by optical fluorescence and reflection microscopy to measure the damage to the structures of the threads processed with oxidizer and in the presence or absence of light

Effect of equilibrium pH on the structure and properties of bleach-damaged human hair fibers.

Hair proteins are significantly affected by environmental pH. This impact tends to increase with prior hair damage. To understand how pH affects bleached hair properties, we utilized a number of techniques allowing for the determination of hair thermal properties, swelling and water sorption, and dry and wet tensile properties. At pH 5, hair proteins had the best structural integrity, as determined by differential scanning calorimetry and the highest tensile modulus. At pH 10, protein cross-linking density decreased, water content and hair cross-sectional diameter increased. Alkaline treatment, when compared with pH 5, did not reduce intermediate filament conditions (evaluated via enthalpy measurement) nor mechanical property performance in the wet state. In contrast to alkaline-treated hair, bleached hair equilibrated at pH 3 behaved very differently: it contained two different crosslink density zones, was the least stiff in dry and stiffest in wet conditions. Additionally, it absorbed less water and had the lowest diameter because of reduced water binding by protonated carboxyl groups. The pH 3 to 10 did not affect the mechanical strength of bleached hair in dry or wet conditions.

Influence of hair treatments on detection of antiretrovirals by mass spectrometry imaging.

Analysis of drugs in hair by mass spectrometry imaging (MSI) has great potential as an objective, long-term measure of medication adherence. However, the fidelity of the chemical record in hair may be compromised by any cosmetic hair treatments. Here, we investigate infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) MSI response to multiple antiretrovirals (ARVs) in cosmetically treated hair. Hair strands from patients on different ARV regimens were mechanically treated with dye, bleach, and relaxer. The treatments had little or no effect relative to untreated controls for cobicistat, abacavir, dolutegravir, maraviroc, efavirenz, and darunavir, but all three treatments removed emtricitabine (FTC) to undetectable levels from patient hair strands. We also evaluated hair strands by IR-MALDESI MSI from 8 patients on FTC-based regimens who reported a range of hair treatments at varying recency prior to hair collection. While FTC was undetectable in the treated portion of these hair strands, ARVs coadministered with FTC remained detectable in hair strands after treatment. We conclude that IR-MALDESI MSI can be used when measuring adherence to ARV therapy, provided that ARVs other than FTC are targeted in people using hair treatments.

Contact allergy to hair cosmetic allergens in Thailand.

BACKGROUND: Hair cosmetics such as hair dyes, bleaching, waving, and cleansing products are composed of numerous chemical ingredients. Allergic reactions to these contact allergens, other than p-phenylenediamine, are rarely reported. OBJECTIVES: To study the incidence of patch test reactions to hair cosmetic allergens and identify the factors associated with hair cosmetic allergy in Thailand. METHODS: We retrospectively reviewed the case records of patients who underwent patch testing from 2009 to 2018. Patients with at least one positive patch test reaction to a potential contact allergen associated with hair cosmetic ingredients were studied. RESULTS: Overall, 2842 patients were patch tested. Of the hair cosmetic allergen categories, preservatives had the highest rate of positive reactions, followed by surfactants and hair dyes. Perming agents were less problematic in comparison. The hands, head, and neck were the predominately affected sites of allergic reactions to hair cosmetic ingredients. CONCLUSIONS: Preservatives, surfactants, and hair dyes are important contact allergens, whereas perming agents are less likely to cause allergic reactions. Hair cosmetic ingredients are regulated by national agencies, which influences their extent of exposure and rates of contact allergies. Further continuous observation of hair cosmetic allergy is needed to provide the best patient care.

Influence of cosmetic hair treatments on cannabinoids in hair: Bleaching, perming and permanent coloring.

Various cosmetic hair manipulations are known to interfere with drug of abuse concentrations in hair. It is important to evaluate the effects of cosmetic hair treatments as they can influence quantitative hair results. Only one study showed a significant decrease of THC after bleaching and coloring. The aim of the study was to investigate the effect of bleaching, perming and dyeing treatment on d-9-tetrahydrocannabinol (THC), but also Cannabidiol (CBD), Cannabinol (CBN) and 11-nor-D9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in hair. Thirty THC-positive hair samples were selected in this study. A single hair lock was divided in 2 separate locks and the proximal 3 cm segment was analyzed. One lock served as control while the other lock was bleached, permed or dyed respectively. Hair was analyzed using a routine method including cleaning, treatment of hair with NaOH and 2 different SPE extractions for THC, CBN, CBD and THC-COOH respectively. Analysis was performed with routine methods using GC/MS-MS in electron impact (EI) mode for THC, CBN and CBD or negative chemical ionization (NCI) mode for THC-COOH after PTV-injection. Bleaching and perming reduced all cannabinoids concentration in hair; THC was more affected than THC-COOH, CBN and CBD. Bleaching caused strong chemical degradation on cannabinoids, while perming exerted more a leaching out effect. Permanent colorings in single applications had only little effects on cannabinoids. Finally this study highlights the importance of considering bleaching and perming for the correct interpretation of hair results.

Influence of bleaching and thermal straightening on endogenous GHB concentrations in hair: An in vitro experiment.

Since gamma-hydroxybutyric acid (GHB) is present in hair of the general population under physiological concentrations, special attention has to be given to the hair analysis of GHB and its interpretation. Normal levels of endogenous GHB can vary in each individual. As a result, strands of hair from a subject have to be cut in small segments (0.3-0.5 cm long) with analysis of each segment. As such, each subject can be used as its own control with a continuous endogenous signal. If one segment has a GHB concentration 10 times higher than the others, this suggests possible administration of exogenous GHB according to the UNODC guideline for Drug Facilitated Assault Cases. AIM: As cosmetic treatments were found to decrease drug concentrations in hair, the aim of the study was to develop an UPLC®-MS/MS method for the analysis of GHB in hair. An in vitro study was then carried out in order to evaluate the impact of a hair straightener or a bleaching treatment on endogenous GHB concentrations. METHOD: Hair samples (10 mg) were washed with dichloromethane and water. After drying overnight in an oven at 35 °C the samples were pulverized in disposable plastic tubes. Methanol/acetonitrile/ammonium formate buffer 1 mM (25:25:50, v/v/v) was used to extract the drug from the hair matrix in a water bath for 1.5 h at 37 °C. Thereafter, the samples were filtered and evaporated to dryness. The dried extracts were then reconstituted in mobile phase and injected in a UPLC®-MS/MS (Waters, Winslow, UK) with a BEH C18 column. RESULTS: The method was validated using untreated hair samples from three healthy volunteers. The calibration curve ranged from 0.06 to 25 ng/mg and the repeatability and intra-batch precision was lower than 20% evaluated in 8 different batches. Processed samples were stable for 3 days in the auto-sampler. To demonstrate the method applicability, 54 hair samples from healthy volunteers were analysed for endogenous GHB resulting in a concentration range from 0.2 to 6 ng/mg. Three different hair treatments experiments were carried out, in which a hair straightener and/or a bleaching treatment were applied. These experiments demonstrated that hair treatments decreased up to 80% of the GHB endogenous concentrations. CONCLUSION: This in vitro study showed that hair bleaching or a heat source treatment influences GHB concentrations in hair. For a correct interpretation of GHB results in hair, cosmetic treatments should be considered, certainly in cases where only a part of the hair is treated.

[Scalp burns induced by hair bleaching]. / Brûlure du cuir chevelu induite par les décolorations capillaires.

BACKGROUND: Hair bleaching is increasingly being carried out in hairdressing salons. The products used are a mixture of hydrogen peroxide and persulfates, both active chemical agents. Scalp burns secondary to hair bleaching are a traumatic adverse effect rarely discussed in publications that continue to be little known among healthcare professionals. PATIENTS AND METHODS: We report the case of a 15-year-old girl with a plaque of scarring alopecia on the vertex. This lesion resulted from a deep burn following a hair-bleaching procedure. Healing took around 4 months, resulting in discomfort for our patient. DISCUSSION: This is a rare case of scarring alopecia following a basic chemical burn to the scalp. The oxidation reaction induced by the mixture of hydrogen peroxide and persulfates, prepared in a basic medium, causes bleaching of the melanin pigments in hair. The clinical presentation of a single, well limited, painful, oozing ulceration located at the vertex was similar to the other cases published in the literature. Although a chemical burning mechanism is most often incriminated, the procedure is always coupled with use of a heat source and associated thermal burn may occur. The delayed appearance of the lesion appears to be caused by the forming of surfactants by the hydrogen peroxide/persulfate mixture, resulting in slow dissolution of the oxidizing compounds within the stratum corneum.

Influence of bleaching and coloring on ethyl glucuronide content in human hair.

Ethyl glucuronide (EtG) is increasingly used in forensic toxicology as a marker for alcohol use in analyses of hair samples, especially in abstinence control. Some cosmetic treatments are considered to markedly reduce the EtG content. In view of especially many women with coloured hair the present study was performed to further investigate the effect of a variety of colouring procedures (bleaching, tinting, permanent and semi-permanent dyeing, henna) on the EtG content. Untreated hair samples (n = 12, EtG 13.9-64.7 pg/mg) were re-analyzed (gas chromatography- negative chemical ionization mass spectrometry, 0.8 pg/mg quantification limit) after different treatment procedures. A decrease of the EtG content of at least 10% occurred in every case. The reduction in comparison to the untreated hair was expectedly high for permanent dyeing and bleaching with 18.1% of the initial content (median, range 0.0-50.9%) and 18.4% (0.0-46.7%), respectively. For henna this was 38.3% (0.0-83.0%), for tinting 70.4% (29.0-90.8%), for semi-permanent dyeing 41.9% (0.0-77.4%). With permanent hair dye the EtG content was decreased to below 7 pg/mg in 10 of 12 cases, in 3 cases even below the LOD (0.2 pg/mg). Surprisingly henna treatment without oxidative component had a marked influence, EtG was below 2 pg/mg in 2 of 12 samples. The study showed that all tested coloration procedures markedly affected the deposited EtG content. Even temporary or henna coloration may have a marked effect. The present data support the recommendation to exclude hair samples with colour manipulations for analysis on the EtG content as a precaution in alcohol abstinence programs. Copyright © 2017 John Wiley & Sons, Ltd.

Dust-free bleaching powder may not prevent symptoms in hairdressers with bleaching-associated rhinitis.

OBJECTIVE: Hairdressers have an increased risk for airway symptoms especially when using hair-bleaching powder containing persulfate. To minimize exposure, dust-free bleaching powder (DFP) has been made available. We studied the effects of regular powder (RP) or DFP on the airway symptoms of hairdressers with hair-bleaching associated rhinitis. METHODS: Twelve hairdressers each performed three hair-bleachings on a wig in an exposure chamber. Half of the subjects used RP and half used DFP. Exposure to persulfate and ammonia was measured. Before and after each bleaching, the participants stated their degree of airway symptoms on a visual analogue scale. Nasal lavage and blood were sampled before exposure, after the last bleaching, and in the morning after exposure to measure inflammatory markers. RESULTS: Exposure to persulfate was higher when using RP compared to DFP, 22 (11-55) vs. 12 (8-13) µg/m3; median (min-max). Exposure to ammonia did not differ between the groups. Both groups reported an increase in asthma-like symptoms and this increase was significant. Neutrophils, lymphocytes, and monocytes increased after exposure in both groups; monocytes decreased the day after. In nasal lavage, IL-8 was increased the morning after for both types of powder, and the increase was significant in the total group. IL-6 increased immediately after exposure and the day after only in the group using RP. CONCLUSIONS: Although DFP powder emits lower levels of persulfate, effects are still elicited in symptomatic hairdressers.

Anaphylactic reaction in a hairdresser due to sensitization to persulphates.

Severe occupational systemic reactions to persulphates have rarely been described and if so mainly after skin contact with bleaching products. We report the first case of a hairdresser with an allergy to persulphates obtained during professional work, who developed anaphylaxis caused by persulphates present in dental cement during dental treatment. This case documents that sensitization to occupational allergens can induce severe systemic reactions outside the workplace. Additionally, it also recommends the need for greater awareness of medical professionals, including dentists, of the possibility of anaphylaxis in patients with occupational allergy.

Characterization of Hairdresser Exposure to Airborne Particles during Hair Bleaching.

Respiratory symptoms among hairdressers are often ascribed to the use of bleaching powders that contain persulfate salts. Such salts can act as allergens and airway irritants but the mechanisms behind the negative health effects are not fully known. In order to understand why some hairdressers experience respiratory symptoms during, and after, sessions of hair bleaching, it is of importance to characterize how exposure occurs. In this work we used time and particle size resolved instrumentation with the aim to measure the concentration of particles that hairdressers are exposed to during sessions of hair bleaching. We also used filter samples to collect particles for quantitative determination of persulfate (S2O8(2-)) content and for analysis by light microscopy. Two different types of bleaching powders were used, one marked as dust-free and one without this marking (denoted regular). The time resolved instrumentation revealed that particles <10 µm were emitted, specifically when the regular powder was prepared and mixed with hydrogen peroxide. In contrast to other research our work also revealed that supercoarse particles (>10 µm) were emitted during application of the bleaching, when both the regular and the dust-free powders were used. The measured level of persulfate, sampled in the breathing zone of the hairdressers, was on average 26 µg m(-3) when the regular powder was used and 11 µg m(-3) when the dust-free powder was used. This indicates that use of dust-free powder does not eliminate exposure to persulfates, it only lowers the concentration. We show that the site of sampling, or position of the hairdresser with regards to the hair being bleached, is of high importance in the determination of persulfate levels and exposure. This work focuses on the physical and chemical characterization of the particles released to the air and the results are important for accurate exposure assessments. Accurate assessments may in turn lead to a better understanding of why some hairdressers experience respiratory symptoms from hair bleaching sessions.

Sub-nm 3D observation of human hair melanin by high-voltage STEM.

The ultrastructure of melanin granules in human hair was studied using 1,000 kV high-voltage scanning transmission electron microscopy to successfully reconstruct three-dimensional images of the whole melanin granule. It was revealed that the melanin granule was composed of a membrane-like outer structure that included many spherical vesicles, and an inner matrix containing a sheet-like structure in the elongated direction of the melanin granule and a sheet-like arrays structure in the cross direction. The outer structure of the melanin granule was maintained even after exposure to hair-bleaching agents to decompose the melanin granule, suggesting that the outer structure was a highly robust structure and composition compared with the inner matrix .

Targeted proteomic analyses of nasal lavage fluid in persulfate-challenged hairdressers with bleaching powder-associated rhinitis.

Hairdressers have an increased risk for developing airway symptoms, for example, asthma and rhinitis. Persulfates, which are oxidizing agents in bleaching powder, are considered important causal agents for these symptoms. However, the underlying mechanisms are unclear. The aim was therefore to measure proteomic changes in nasal lavage fluid from persulfate-challenged subjects to identify proteins potentially involved in the pathogenesis of bleaching powder-associated rhinitis or candidate effect biomarkers for persulfate. Also, oxidized peptides were measured to evaluate their usefulness as biomarkers for persulfate exposure or effect, for example, oxidative stress. Samples from hairdressers with and without bleaching powder-associated rhinitis were analyzed with liquid chromatography tandem mass spectrometry using selected reaction monitoring to target 246 proteins and five oxidized peptides. Pathway analysis was applied to obtain a functional overview of the proteins. Several proteins involved in biologically meaningful pathways, functions, or disorders, for example, inflammatory responses, oxidative stress, epithelium integrity, and dermatological disorders, changed after the persulfate challenge. A list with nine proteins that appeared to be affected by the persulfate challenge and should be followed up was defined. An albumin peptide containing oxidized tryptophan increased 2 h and 5 h after the challenge but not after 20 min, which indicates that such peptides may be useful as oxidative stress biomarkers.

Hydrogen peroxide reactions on cocaine in hair using imaging mass spectrometry.

Today, forensic hair analysis is considered to be a standard method for identifying chronic drug users since information about drug use stored and located in hair can cover several months to even years. When interpreting these results, one should be aware of all kind of pitfalls. External factors such as bleaching might influence the analytical result. Although the effect of hydrogen peroxide on cocaine in a solution was described before, it was never investigated whether the described reaction products (ecgonine methylester, benzoylecgonine, hydroxynorcocaine and dihydroxycocaine) are indeed found on contaminated or user hair. Since it is of great importance in forensic hair analysis to know whether cocaine and/or reaction products are detectable in hair after bleaching, matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was used to study the effect of hydrogen peroxide treatment on incorporated cocaine in hairs. Cocaine oxidation products were identified in a solution based on MS/MS spectra and spatial distribution of these products in hair was explored using MALDI TOF-MS. All images were accomplished by spraying α-Cyano-4-hydroxycinnamic acid (CHCA) as a MALDI-matrix. Images revealed a loss of detectability of cocaine and its reaction products in hairs already after a short bleaching period. Since all compounds of interest are found in the hydrogen peroxide and wash solution, these findings indicate that all evidence of cocaine use might be lost after a hair bleaching treatment. Therefore, forensic toxicologists should take into consideration whether hair samples were bleached before making any conclusions from hair analysis results.

Yellowing and bleaching of grey hair caused by photo and thermal degradation.

Yellowing is an undesirable phenomenon that is common in people with white and grey hair. Because white hair has no melanin, the pigment responsible for hair colour, the effects of photodegradation are more visible in this type of hair. The origin of yellowing and its relation to photodegradation processes are not properly established, and many questions remain open in this field. In this work, the photodegradation of grey hair was investigated as a function of the wavelength of incident radiation, and its ultrastructure was determined, always comparing the results obtained for the white and black fibres present in grey hair with the results of white wool. The results presented herein indicate that the photobehaviour of grey hair irradiated with a mercury lamp or with solar radiation is dependent on the wavelength range of the incident radiation and on the initial shade of yellow in the sample. Two types of grey hair were used: (1) blended grey hair (more yellow) and (2) grey hair from a single-donor (less yellow). After exposure to a full-spectrum mercury lamp for 200 h, the blended white hair turned less yellow (the yellow-blue difference, Db(*) becomes negative, Db(*)=-6), whereas the white hair from the single-donor turned slightly yellower (Db(*)=2). In contrast, VIS+IR irradiation resulted in bleaching in both types of hair, whereas a thermal treatment (at 81 °C) caused yellowing of both types of hair, resulting in a Db(*)=3 for blended white hair and Db(*)=9 for single-donor hair. The identity of the yellow chromophores was investigated by UV-Vis spectroscopy. The results obtained with this technique were contradictory, however, and it was not possible to obtain a simple correlation between the sample shade of yellow and the absorption spectra. In addition, the results are discussed in terms of the morphology differences between the pigmented and non-pigmented parts of grey hair, the yellowing and bleaching effects of grey hair, and the occurrence of dark-follow reactions.

Is urine an alternative to cosmetically treated hair for the detection of drugs and alcohol?

This study attempts to assess the utility of the urine matrix as an alternative to cosmetically treated hair for the detection of drugs and alcohol for driving licence re-granting in 1026 cosmetically treated hair samples and 33 262 urine routine samples. No significant difference was observed between the percentage positive samples in cosmetically treated hair to those in urine at both the 95% and 99% significance level for amphetamines, cocaine, opiates, benzodiazepines, and methadone. Significant difference was found between the positivity rates of cannabinoids in cosmetically treated hair and that in urine indicating urine to be a better alternative to the use of the hair matrix even when cosmetically treated. The opposite was observed for the alcohol consumption marker ethyl glucuronide (EtG) for which the positivity rate in cosmetically treated hair was twice that in urine samples. Particularly for alcohol abstinence monitoring, as for the rehabilitative driving licence re-granting medical and psychological assessment (MPA) programme in Germany, it seems that ethyl glucuronide (EtG) in hair presents a much better alternative than urine testing, even when cosmetically treated hair is analyzed. Moreover, segmentation is an additional advantage of hair testing which can provide additional useful information.

Hair cosmetics: dyes.

Hair plays a significant role in body image, and its appearance can be changed relatively easily without resort to surgical procedures. Cosmetics and techniques have therefore been used to change hair appearance since time immemorial. The cosmetics industry has developed efficient products that can be used on healthy hair or act on concomitant diseases of the hair and scalp. Dyes embellish the hair by bleaching or coloring it briefly, for temporary periods of longer duration, or permanently, depending on the composition of a dye (oxidative or nonoxidative) and its degree of penetration of the hair shaft. The dermatologist's knowledge of dyes, their use, and their possible side effects (contact eczema, cancer, increased porosity, brittleness) can extend to an understanding of cosmetic resources that also treat hair and scalp conditions.

Compositional changes of human hair melanin resulting from bleach treatment investigated by nanoscale secondary ion mass spectrometry.

BACKGROUND/PURPOSE: It is important to understand the influence of bleach treatment on human hair because it is one of the most important chemical treatments in hair cosmetic processes. A comparison of the elemental composition of melanin between virgin hair and bleached hair would provide important information about the structural changes of melanin. To investigate the elemental composition of melanin granules in virgin black hair and bleached hair, these hair cross-sections are analyzed by using a nanoscale secondary ion mass spectrometry (NanoSIMS). METHODS: The virgin black hair and bleached hair samples were embedded in resin and smooth hair cross-sections were obtained using an ultramicrotome. NanoSIMS measurements were performed using a Cs(+) primary ion beam to detect negative secondary ions. RESULTS: More intensive (16) O(-) ions were detected from the melanin granules of bleached hair than from those of virgin black hair in NanoSIMS (16) O(-) ion image. In addition, it was indicated that (16) O(-) ion intensity and (16) O(-) /(12) C(14) N(-) ion intensity ratio of melanin granules in bleached hair were higher than those in virgin black hair. CONCLUSION: Nanoscale secondary ion mass spectrometry analysis of the cross-sections of virgin black hair and bleached hair indicated that the oxygen content in melanin granules was increased by bleach treatment.