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Background: Solar radiation is responsible for changes in the structure of human hair, the damages include proteins (65%-95%), lipids, and melanin. The aim was to examine the effectiveness of sunscreen in hair cosmetics and whether hair color affects it., Materials and Methods: The study included nine women, divided according to hair color to three groups: light, dark, and gray hair. The 410-Solar reflectometer was used in five time points. The hair was divided into three strands, one product applied to each., Results: Dark hair showed the highest absorption of radiation in all wavelength ranges, the reflectance before products application was significantly higher than the hair reflectance immediately after application. The effect of sunscreens on light hair reflectance was found at wavelengths 400 and 720 nm and between 1000 and 2500 nm, the reflectance before application was significantly higher than the reflectance after. The use of products on gray hair did not have a significant effect on hair reflectance at wavelengths 400-1100 nm, the effect of sunscreens on the gray hair reflectance was observed in the UV and infrared range, the reflectance before application was significantly higher than immediately after., Conclusions: The results showed that the 410-Solar reflectometer is useful to assess the effectiveness of hair sunscreens. All three tested hair products do not show the expected protection properties. Dark hair showed the highest absorption of radiation in all wavelength ranges, suggesting that dark hair should be more protected against radiation than light and gray hair., (© 2023 The Authors. Skin Research and Technology published by John Wiley & Sons Ltd.)

Objective: This study explores the applicability and scientific accuracy of instrument measurements in repairing hair products on slightly damaged hair bundles., Materials and Method: Sixty hair bundles mildly damaged with hydrogen peroxide and ammonia standards were divided into two groups: the treatment and control groups (30 hair bundles each). The treatment group used commercial hair care essential oil, whereas the control group used tap water to treat the damage. The two groups were measured using an instrument before and after the product application. The objective indicators included the gloss of hair, along with hair cuticle dynamic friction coefficient, and against hair cuticle dynamic friction coefficient. At the same time, two evaluators conducted sensory evaluations on the gloss and frizz levels of the hair bundles. Therefore, data comparison and verification were carried out together with instrumental measurement data., Results: We verified that the instrumental measurement methods could obtain data trends that are consistent with sensory assessment methods; hence, they have the advantages of accuracy, convenience, and quantifiability., Conclusion: Thus, the instrumental measurement methods we verified can provide objective evidence for the efficacy of hair care products in repairing hair., (© 2023 The Authors. Skin Research and Technology published by John Wiley & Sons Ltd.)

Background: The process of hair dyeing causes hair damage, and periodic re-dyeing is required for newly grown hair. To avoid these hassles, hair color shampoos have been developed and are widely used. In this study, we compared the effects of two hair color shampoos with different dyeing principles to analyze the function of hair color shampoos. We analyzed hair tresses treated by hair-oxidation- and hair-coating-based shampoos., Materials and Methods: We measured the color, tensile properties, softness, elasticity, gloss, moisture content, and protein content of the hair tresses dyed with color shampoos. The hair structures were analyzed by scanning and transmission electron microscopies (SEM and TEM) and a hydroxy radical-based method., Results: The shampoo based on hair coating enhanced the hair dyeing effect and roughness, whereas that based on hair oxidation improved the color retention and moisture content in the hair tresses. Frictional resistance, gloss, and elasticity of the hair tresses were similar for the two products. However, according to the results of the protein loss test, TEM, and hydroxyl radical staining, the shampoo based on hair oxidation showed a longer dyeing retention compared to that based on hair coating but caused cuticle damage., Conclusion: These results show that the two shampoos with different dyeing principles exhibit different hair dyeing abilities and hair health indices. Therefore, we recommend that hair color shampoos should be used according to the requirements of an individual., (© 2023 The Authors. Skin Research and Technology published by John Wiley & Sons Ltd.)

Background: The mechanical properties of hair treated with styling ingredients is an important aspect to determine if products will be efficacious when used by the consumer. Measurement techniques have been proposed in earlier work; however, these are mostly aimed at hairspray systems and not the myriad of styling products available to the modern-day consumer., Aim: In this article, experimental and data analysis guidelines are proposed for the evaluation of styling ingredients using a three-point cantilever bending technique. Most of the experiments were carried out on polysaccharide-based ingredients-guar hydroxypropyltrimonium chloride (Guar HPTC) and cassia hydroxypropyltrimonium chloride (Cassia HPTC)-to establish basic characterization concepts of the polymer-fiber assemblies., Methods: A three-point cantilever bending technique was developed using a texture analyzer housed in a temperature and humidity-controlled chamber. Scanning electron microscopy (SEM) studies were conducted to monitor the fracture mechanics of polymer-fiber assemblies., Results: Fundamental studies were carried out to determine the effect of concentration, molecular weight (MW), and chemistry of the polysaccharides on the calculated indices, which characterize the stiffness, flexibility, elasticity, and plasticity of the treated hair. Experiments were conducted in a controlled temperature and humidity environment, which allowed us to monitor the behavior of the polymer-treated hair from 40-90% RH. Studies were also conducted on polymer blends and conventional styling polymers to provide guidance of the performance of naturally-derived polymers to their synthetic counterparts., Conclusions: A detailed description is provided for a user-friendly, quick method to measure the mechanical properties of styling ingredients on hair. We provide guidelines for three-point cantilever bending tests of straight hair tresses treated with conventional and naturally-derived styling polymers. Indices were developed to characterize the force-distance curves and were designated as E1, F1, position of F1, post-fracture gradient, toughness, E10/E1, and F10/F1. These indices provide an overall characterization of the stiffness, flexibility, elasticity, and plasticity of polymer-treated hair., (© 2022 The Authors. Skin Research and Technology published by International Society for Bioengineering and the Skin.)

Objective: Based on in vivo data, in vitro models and new methods are created to mimic the impact of aerial pollution onto the hair surface and assess the efficacy of different formulae prototypes., Material and Methods: Two protocols are developed to mimic the pollution effect, in vitro, on purchased swatches, and in vivo, on scalps and forearms. First, with an artificial sebum mixed with Carbon Black particles, named "sebollution," we evaluated, through an instrumental color measurement, the cleansing efficacy of some shampoo on scalp and hair. The second protocol allowed to assess the interaction between hair care product deposit (shampoo, conditioner, mask, and leave-on) on hair and carbon black particles spread on fiber. The quantification of particle coverage allowed to evaluate the efficiency of a formula to limit the aerial pollution deposit on hair fiber., Results: To simplify and accelerate the evaluation of 42 shampoo formulae, an extrapolation of the scalp cleaning process was validated on forearm. The respective cleanabilities were calculated and covered a large range of efficacy, from 5%, for a basic bland shampoo generally used to reset swatches, to a strong deep cleansing efficacy of 100%. On hair swatches, cleanability efficiencies of five shampoo were also evaluated to eliminate the deposited of sebollution, in a range of 40%-80%. To quantify the efficacy of preventing the deposition of carbon particle on hair surface, the percentage of coverage of 45 different products was measured, from 2% to 16%. The performance depended of the product category (shampoo, conditioner, mask, and leave-on), driven by the performance of the product deposit, and the capacity of this deposit to interact with aerial pollution., Conclusion: Three new protocols and evaluation methods are proposed to evaluate and quantify the performance of hair care product, to remove/clean, limit, and protect the hair fibers against the aerial pollution that could interact with hair, scalp and sebum. The validation of these approaches was done through the testing of a large panel of hair care product leading to a complete and sincere evaluation of cleansing and anti-deposit efficacy. Combining the knowledge acquired on pollution impact on hair and the development of specific way of evaluation, this work reinforced the rationale of using and developing new cosmetic products that reduced the impact of pollution upon some hair properties., (© 2023 The Authors. Skin Research and Technology published by John Wiley & Sons Ltd.)

Background: The regreasing process of hair by sebum is daily observed by consumers. Methods to investigate this phenomenon were scarcely updated since the 1990s, despite the constant progresses in hair cleaning procedures or shampoo formulations. Our objective was first, to develop an in vivo noninvasive method for quantifying the spread of sebum along the hair shaft. Secondly, we use this new method to define the overall kinetics of the hair-regreasing process among two cohorts of Chinese men with opposite self-perceptions of their scalp/hair greasiness (ie, greasy or not greasy)., Material and Methods: One hundred and twenty-three Chinese men (aged 18-35 years) participated to the study. The technique used basically adapts the Sebumeter™ technology where supple polymer films are applied onto and along the hair shaft. The sampled hair sebum is further quantified by image analysis/increased transparency., Results: The technique developed showed an adequate reproducibility under fixed conditions (pressure, investigators, scalp sites, etc.). In the two cohorts of subjects (eg, greasy, nongreasy), hair regreasing process was found sharing a same linear progression with time. The two cohorts of men presented significantly different values in the total amount of spread sebum by an approximately two-fold coefficient, with however comparable average values in the sebum amount present at the root region 48 hours post shampoo. At such timing, the spread of sebum reaches much longer distances in the greasy scalp cohort., Conclusion: This technique appears promising for assessing the efficacy of cosmetic ingredients (or products) that aim at delaying a natural process that is daily and negatively perceived by consumers., (© 2018 The Authors. Skin Research and Technology Published by John Wiley & Sons Ltd.)

Background/purpose: Focus on the hair and hair cuticle is increasing. The hair cuticle is the first layer to be exposed to damage and the area of primary protection. For such reasons, hair product manufacturers consider cuticle protection important. However, previous studies used only visual assessment to examine the cuticle. This study aimed to obtain the changes in cuticles and measure hair roughness using a HIROX microscope., Methods: A total of 23 female subjects used the same products daily for 4 weeks. Three hair samples per subject were collected from three different areas of the head. Measurements were taken before and after 4 weeks of daily product use., Results: The hair surface changes were clearly observed on the captured images. Moreover, hair surface roughness was observed using various parameters on HIROX software. After 4 weeks of daily product use, the roughness parameter value of the hair surface was significantly decreased., Conclusion: Our result suggests that the hair roughness analytical method using HIROX can be a new paradigm for high-quality quantitative analysis of the hair cuticle., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background/purpose: Hair straighteners are very popular around the world, although they can cause great damage to the hair. Thus, the characterization of the mechanical properties of curly hair using advanced techniques is very important to clarify how hair straighteners act on hair fibers and to contribute to the development of effective products. On this basis, we chose two nonconventional hair straighteners (formaldehyde and glyoxylic acid) to investigate how hair straightening treatments affect the mechanical properties of curly hair., Methods: The mechanical properties of curly hair were evaluated using a tensile test, differential scanning calorimetry (DSC) measurements, scanning electronic microscopy (SEM), a torsion modulus, dynamic vapor sorption (DVS), and Fourier transform infrared spectroscopy (FTIR) analysis., Results: The techniques used effectively helped the understanding of the influence of nonconventional hair straighteners on hair properties. For the break stress and the break extension tests, formaldehyde showed a marked decrease in these parameters, with great hair damage. Glyoxylic acid had a slight effect compared to formaldehyde treatment. Both treatments showed an increase in shear modulus, a decrease in water sorption and damage to the hair surface., Conclusions: A combination of the techniques used in this study permitted a better understanding of nonconventional hair straightener treatments and also supported the choice of the better treatment, considering a good relationship between efficacy and safety. Thus, it is very important to determine the properties of hair for the development of cosmetics used to improve the beauty of curly hair., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background/purpose: The water content of hair can be evaluated by weighing, the Karl Fischer method, and from electrical properties. However, these methods cannot be used to study the distribution of water in the hair. Imaging techniques are required for this purpose. In this study, a highly sensitive near-infrared (NIR) imaging system was developed for evaluating water in human hair. The results obtained from NIR imaging and conventional methods were compared., Methods: An extended indium-gallium-arsenide NIR camera (detection range: 1100-2200 nm) and diffuse illumination unit developed in our laboratory were used to obtain a NIR image of hair. A water image was obtained using a 1950-nm interference filter and polarization filter. Changes in the hair water content with relative humidity (20-95% RH) and after immersion in a 7% (w/w) sorbitol solution were measured using the NIR camera and an insulation resistance tester. The changes in the water content after treatment with two types of commercially available shampoo were also measured using the NIR camera., Results: As the water content increased with changes in the relative humidity, the brightness of the water image decreased and the insulation resistance decreased. The brightness in the NIR image of hair treated with sorbitol solution was lower than that in the image of hair treated with water. This shows the sorbitol-treated hair contains more water than water-treated hair. The sorbitol-treated hair had a lower resistance after treatment than before, which also shows that sorbitol treatment increases the water content. With this system, we could detect a difference in the moisturizing effect between two commercially available shampoos., Conclusion: The highly sensitive imaging system could be used to study water in human hair. Changes in the water content of hair depended on the relative humidity and treatment with moisturizer. The results obtained using the NIR imaging system were similar to those obtained using a conventional method. Our system could detect differences in the moisturizing effects of two commercially available shampoos., (© 2012 John Wiley & Sons A/S.)

Background: Procyanidins are a subclass of flavonoids and consist of oligomers of catechin that naturally occur in plants and are known to exert many physiological effects, including antioxidant, anti-inflammatory, and enzyme inhibitory effects. These possible inhibitory effects of the procyanidins were known to involve metal chelation, radical trapping, or direct enzyme binding., Purpose: The purpose of this study was to investigate the effect of procyandin oligomers on hair damage induced by oxidative stress., Results: In this study, several methods for evaluating oxidative damage in bleached hair are utilized to analyze the protective effect of procyandin oligomers against oxidative hair damage. It was observed that procyanidin oligomers strongly bind to keratin in hair and inhibit the breakdown of hair caused by oxidative damage in an analysis of hair using electrophoresis, transmission electron microscope, and fluorescence dye., Conclusion: These results confirm that procyanidin oligomers can be applicable as a potential candidate to the development of hair care with protective effect on hair damage., (© 2011 John Wiley & Sons A/S.)

Background/purpose: The continuous advancement in cosmetic science has led to an increasing demand for the development of non-invasive, reliable scientific techniques directed toward claim substantiation, which is of utmost relevance, to obtain data regarding the efficacy and safety of cosmetic products., Methods: In this work, we used the optical coherence tomography (OCT) technique to produce in vitro transversal section-images of human hair. We also compared the OCT signal before and after chemical treatment with an 18% w/w ammonium thioglycolate solution., Results: The mean diameter of the medulla was 29+/-7 microm and the hair diameter was 122+/-16 microm in our samples of standard Afro-ethnic hair. A three-dimensional (3D) image was constructed starting from 601 cross-sectional images (slices). Each slice was taken in steps of 6.0 microm at eight frames per second, and the entire 3D image was constructed in 60 s., Conclusion: It was possible to identify, using the A-scan protocol, the principal structures: the cuticle, cortex and medulla. After chemical treatment, it was not possible to identify the main structures of hair fiber due to index matching promoted by deleterious action of the chemical agent.

Shampoos are the most frequently prescribed treatment for the hair and scalp. The different qualities demanded from a shampoo go beyond cleansing. A cosmetic benefit is expected, and the shampoo has to be tailored to variations associated with hair quality, age, hair care habits, and specific problems related to the condition of the scalp. The reciprocal relationship between cosmetic technology and medical therapy is reflected in the advances of shampoo formulation that has made applications possible that combine benefits of cosmetic hair care products with efficacy of medicinal products. A shampoo is composed of 10 to 30 ingredients: cleansing agents (surfactants), conditioning agents, special care ingredients, and additives. Since the cleansing activity depends on the type and amount of surfactants utilized, shampoos are composed of a blend of different surfactants, depending on the requirements of the individual hair type. Development time from the concept to the commercial shampoo may take longer than a year. Much effort is invested in the development of conditioning agents, which impart luster, smoothness, volume and buoyancy. Another prerequisite is a scalp free of scaling. Current anti-dandruff agents primarily have an antimicrobial mode of action, and inhibit growth of Malassezia spp. Recent developments in shampoo technology have led to increased efficacy of anti-dandruff agents, allowing shorter contact time, and reducing irritation.