Hair cosmetics: an overview

Cationic cellulose nanocrystals enhance keratin adsorption to improve hair glossiness and thermal-photo protection

The functional chemicals in conventional personal care products may have negative effects on both human body and the environment, and natural proteins are gaining increasing attention as alternatives to functional chemical. However, due to the poor absorption of proteins on the surface of the hair, it cannot perform their function well. In this study, a protein-based multifunctional complexes, made of keratin and cationic cellulose nanocrystals by opposite charged-induction, were prepared for improving the glossiness and reducing hair thermal-photo damage. By changing the ratio of keratin and cationic cellulose nanocrystals in complexes, the optical properties and oil delivery property were studied. It was found that the protein-based complexes could improve the glossiness of substrate and have synergistic reducing UV transmittance, especially UVB. Besides, the complexes with high ratio of C-CNC were beneficial for the deposition of silicone oil onto hair. And after treated with the complexes or the resulting emulsion, the water evaporation of hair during heat treatment and the hair damage during light radiation were effectively reduced to improve the thermal-photo protection for hair. This study was expected to provide new design for improving adsorption of protein on the substrate and developing protein multifunctional application in personal care.

Insights into structural and proteomic alterations related to pH-induced changes and protein deamidation in hair

OBJECTIVES

The hair shaft is often exposed to shampoo and haircare products that have unknown or varying pH levels. These products contain a combination of surfactants and other active ingredients to treat the hair or the scalp. As amphoteric proteins, hair keratins have limited buffering capacity, so variations in pH can have multifaceted impacts on them. However, there is limited knowledge about how pH affects keratins and keratin-associated proteins (KAPs). Therefore, this study aims to examine the effects of varying pH levels (pH 3-pH 12) on hair structure and analyse consequent alterations in the hair proteome using mass spectrometry-based proteomics.

METHODS

A scanning electron microscope was used to examine changes in hair-shaft morphology due to exposure to various pH levels, while mass spectrometry was employed to analyse protein alterations.

RESULTS

We found that exposing the hair shaft to varying pH levels led to specific effects on the cuticle, including cuticle lifting at certain pH levels, while proteomics analysis identified alterations in the hair proteome along with significant deamidation of keratins types I and II and KAPs. More pronounced effects were observed at extreme acidic conditions (pH 3) and alkaline conditions (above pH 8) on both hair morphology and hair proteins. pH levels between pH 5 and pH 7 had minimal impact on hair structure and proteins, suggesting that haircare products with pH in this range are ideal for hair-shaft health. In contrast, alkaline pH levels were found to negatively affect hair.

CONCLUSIONS

The structure evaluation and proteomics data emphasize the critical role of pH in hair health. The extreme acidic or alkaline pH impacts the hair structure and hair proteins. The study highlights the optimal pH range for maintaining healthy hair.

PM10 exposure in beauty salons: impact on A549 cell viability, cell cycle, oxidative stress, and mutagenicity

Beauty salons are unique indoor environments where elevated PM10 levels may arise from frequent use of personal care and cosmetic products, potentially exposing salon workers and clients to harmful chemicals. This study aimed to assess the biological effects of PM10 collected indoors and outdoors of a beauty salon, as well as the mutagenic potential of PM10-bound polycyclic aromatic hydrocarbons (PAHs). Using the MTT test, a dose-dependent decrease in cell viability was observed in human alveolar adenocarcinoma cells (A549) exposed to PM10, with indoor samples causing more pronounced effects than outdoor and background air. Indoor PM10 exposure also increased intracellular reactive oxygen species (ROS) and caused an arrest in the G1 phase of cell cycle. These biological responses were correlated with the concentrations of various compounds, including organic carbon (OC), aliphatic carboxylic acids, dicarboxylic acids, and alkyl esters of fatty acids. No mutagenic effects were observed for all PAH samples tested using the Salmonella typhimurium strain TA98. The findings suggest that beauty salons might have elevated levels of PM10, capable of inducing cytotoxic and oxidative stress-related effects and cell cycle disruption. Although no mutagenic activity was detected, the presence of harmful chemicals highlights potential health risks for workers and clients.

Composite Fish Collagen Peptide-Based Biopolymer Emulsion for Keratin Structure Stabilization and Hair Fiber Repair

Marine-derived proteins, rich in amino acids and bioactivity, serve as a natural and safe alternative to chemical haircare products. This study selected three highly bioactive fish-derived protein peptides and determined their optimal repair ratio using FTIR structural analysis and response surface methodology (RSM). A collagen peptide-based composite human hair repair emulsion (CHFRE) was formulated, and its repair efficacy on damaged hair (DH) was evaluated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and amino acid analysis. Following CHFRE treatment, the physical and chemical properties of damaged hair improved significantly. SEM analysis revealed enhanced hair luster, aligned cuticle scales, and a denser cortex. FTIR and DSC analyses showed a 5.94% increase in α-conformation content and a 28.44% rise in relative helical content (RHC), indicating enhanced protein stability and a conformation closer to that of normal hair. Additionally, the 14.63% increase in S=O transmittance suggested reduced oxidative damage. Amino acid analysis and hydrophobic amino acids, with specific increments of 16.77 g/100 g and 2.47 g/100 g, respectively, enhance hair affinity and keratin stability. This bio-based repair material effectively restores damaged hair structure, strengthens resistance to chemical damage, and ensures sustainability, safety, and biocompatibility, providing a promising approach for the development of natural hair repair products.

The exposome impact on hair health: non-pharmacological management. Part II⋆

Hair holds a significance that surpasses mere aesthetics, as it plays a pivotal role in our social interactions and contributes significantly to the definition of our self-esteem. Central to this understanding is the concept of the exposome, which encompasses intrinsic elements like genetics and physiological changes, as well as extrinsic factors such as UV radiation, pollution, lifestyle choices, and chemical treatments. These factors may significantly impact hair health and hair aging. Expanding upon the groundwork laid by the first part of this research (Cedirian et al., 2024), this study aims to deepen our understanding of exposome influence on hair. Specifically, through a narrative review of current literature, this second part endeavors to provide non-pharmacological treatment solutions and effective strategies to mitigate the negative impact of the exposome on hair health.

Polyphenol-Inorganic Sulfate Complex-Enriched Straightening Shampoo for Reinforcing and Restoring Reduced Hair Integrity

Conventional hair-straightening methods that use chemical treatments to break disulfide bonds cause severe damage to the hair shaft, leading to weakened hair that is prone to reverting to its curly form in high humidity. Therefore, a unique haircare coating technology is required to protect hair integrity and provide a long-lasting straightening effect. Herein, we designed a hair-straightening technology by integrating a nature-inspired polyphenol-inorganic sulfate (PIS) redox agent into formulated shampoo, which achieves a desirable straightening effect through sulfate-induced disulfide breakage while preserving hair integrity through a polyphenol-reinforced structure. The interaction between polyphenols and residual thiols from the straightening process maintained a long-lasting straight hair structure and hair strength. Ellman's assay showed a lower free thiol content from reductant-induced damaged keratin in PIS shampoo-treated hair than in sulfate-treated hair as the polyphenol-thiol bond was formed through the Michael addition reaction, thereby restoring the natural structure of the hair and enhancing its mechanical properties. Owing to the polyphenol coating, PIS shampoo-treated hair exhibited an antistatic effect and high hydrophobicity, indicating healthy hair. Furthermore, the polyphenol coating effectively scavenged radical oxygen species (ROS) in the hair, thereby improving damage protection. Thus, PIS shampoo offers an alternative approach for effective hair straightening.

Types and Characteristics of Hair Across the Globe: Results of a Multinational Study on 19,461 Individuals

Introduction

Hair plays a critical role in enhancing physical appearance, self-esteem, and identity. However, the impact of hair characteristics on daily life has received limited attention. This study aimed to assess the types and characteristics of hair, their variations according to age, gender, ethnicity, and country, and their effects on individuals' daily lives.

Methods

A study was conducted between February 2022 and June 2023 across nine countries: USA, France, Brazil, India, China, Mexico, Japan, South Africa, and Indonesia. A total of 19,461 participants aged 18 and older were selected using stratified, proportional sampling. Participants completed a structured digital questionnaire evaluating hair thickness, type, damage, and curl degree, alongside questions on stress, sleep, and well-being. Data were analyzed using descriptive statistics and statistical tests (T-test, Pearson's test).

Results

Thin hair was reported by 23.7% of males and 29.2% of females. Dry hair was more common in females (38.9%) than males (32.1%). Damaged hair was reported by 47% of females and 30% of males. Ethnic differences showed that thick hair was most common in African (40.7%) and least in Asian (26.3%) populations. The impact of hair type on daily life varied significantly across countries. Individuals with damaged or dry hair experienced higher stress, lack of sleep, and poor well-being, especially in Japan, India, and France. Hair type (straight, wavy, curly, kinky) also affected personal and professional stress levels differently in each country.

Conclusion

Our research shows that hair characteristics significantly influence daily life, self-image, and well-being, with notable variations by gender, ethnicity, and country. These findings highlight the need for interventions to address the psychological and social impacts of hair issues, contributing to better healthcare, body image, and product development.

The exposome impact on hair health: etiology, pathogenesis and clinical features ‒ Part I

Human hair, particularly on the scalp, serves as a significant aspect of social identity and well-being. The exposome, encompassing both intrinsic and extrinsic factors, plays a fundamental role in hair weathering. Intrinsic factors include genetic predispositions and physiological changes within the body, while extrinsic factors comprise environmental exposures such as UV radiation, pollution, humidity, temperature variations, lifestyle choices, and chemical treatments. These elements collectively contribute to the cumulative damage experienced by hair over time. Understanding the comprehensive impact of the exposome on hair health and hair aging necessitates an exploration of various environmental conditions, lifestyle factors, and technical artifacts. Despite advancements in research, the intricate mechanisms underlying the exposome influence on hair remain incompletely understood. Through a comprehensive review of current literature and emerging research findings, this study aims to enhance the understanding of exposome impact on hair health.

Biomimetics through bioconjugation of 16-methylheptadecanoic acid to damaged hair for hair barrier recovery

The primary component of the lipid barrier on human hair, which is essential for defense against aging and environmental stresses, is 18-methyleicosanoic acid (18-MEA), which provides hydrophobic properties and protective benefits. Since 18-MEA cannot be regenerated once damaged, developing technology that can permanently bind alternative materials to hair is critical. Once 18-MEA was removed from hair via X-ray photoelectron spectroscopy (XPS), pentaerythritol tetraisoosterate (PTIS) was hydrolyzed and observed via gas chromatography/mass spectrometry (GC/MS) to confirm that it mimicked 18-MEA, and 16-methylheptadecanoic acid (16-MHA) was obtained at pH 4 or lower. 16-MHA was bioconjugated to damaged hair from which 18-MEA was removed via a carbodiimide reaction using polycarbodiimide. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) confirmed that 16-MHA remained on the surface of the bioconjugated hair even after washing. Observation of the endothermic reaction of moisture in hair via a differential scanning calorimetry (DSC) and evaluation of the moisture content confirmed that the physical properties of hair enriched with 16-MHA were similar to those of virgin hair. This biomimetic approach has been shown to restore both external structural integrity and internal moisture homeostasis.

Ginseng and ginseng byproducts for skincare and skin health

Ginseng is a traditional herbal medicine with a long history of use for the prevention and/or treatment of various diseases. Ginseng is used worldwide as a functional food to maintain human health. In addition, ginseng has been used as a raw ingredient in cosmetics with various applications, ranging from skin toning to anti-aging. Some cosmetic products contain ginseng extracts from Korea and other countries, as it is thought that ginseng can also exert beneficial effects on human skin. However, it remains unclear which ginseng component(s) could be the main active compound that directly contributes to skin health and/or prevents skin aging. It is also important to understand the mechanisms by which the ginseng component(s) exert their effects on the skin and skin health. This review describes recent in vitro and in vivo studies involving ginseng extracts, ginseng ingredients, and ginseng byproducts for skincare and skin health and discusses emerging evidence that ginsenosides, gintonin, and ginseng byproducts could be novel candidates for skincare and skin health applications ranging from anti-aging to the treatment of skin diseases such as atopic dermatitis and hypertrophic scars and keloids. The mechanisms underlying the beneficial effects of ginseng components and byproducts on skin health are discussed. In addition, this review shows how ginseng components, such as gintonin, a newly identified ginseng component, might contribute to skin health and skin disease when used as a supplementary ingredient in cosmetics and further proposes a novel combination in cosmetic products containing both ginsenosides and gintonin.

Hair product use and urinary biomarker concentrations of non-persistent endocrine disrupting chemicals among reproductive-aged Black women

BACKGROUND

Studies have shown an association between hair product use and adverse health outcomes. Scientists have hypothesized that exposure to endocrine-disrupting chemicals (EDCs) drives these associations, but few studies have directly evaluated associations between hair product use and biomarkers of EDCs. Even more limited are studies of Black women, who frequently use EDC-containing products (e.g., hair relaxers).

OBJECTIVE

We estimated associations between hair product use and EDC biomarker concentrations.

METHODS

We leveraged cross-sectional data from the Study of Environment, Lifestyle, and Fibroids, a cohort of females aged 23-34 years who self-identified as Black/African American from the Detroit-metropolitan area (USA; n = 425). On structured questionnaires, participants reported their past 24-h and past 12-month use of hair products, including relaxers/straighteners/perms, styling products, moisturizers, oils, and hair food. We quantified urinary concentrations of 19 phthalate/phthalate alternative metabolites, 7 phenols, and 4 parabens using high performance liquid chromatography isotope dilution tandem mass spectrometry. EDC biomarker concentrations were creatinine-adjusted and natural log-transformed. We used multivariable linear regression to estimate mean percent differences in EDC biomarker concentrations and 95% confidence intervals (CIs) associated with hair product use, adjusting for sociodemographic confounders.

RESULTS

Hair product use was associated with greater concentrations of multiple EDC biomarkers. Notably, use of hair products in the previous 24 h (compared with non-use) was associated with 16.2% (95% CI = 0.7%, 35.9%), 35.0% (95% CI = 2.6%, 77.6%), and 32.3% (95% CI = 8.8%, 92.0%) higher concentrations of mono-isobutyl phthalate, methyl paraben, and ethyl paraben, respectively. Use of hair relaxers/straighteners/perms, styling products, moisturizers, oils, and hair food in the past 12 months was also associated with higher concentrations of multiple phthalate, phenol, and paraben biomarkers.

CONCLUSION

Hair product use was associated with higher biomarker concentrations of multiple phthalates, phenols, and parabens. These findings suggest that hair products are potentially important exposure sources for hormonally-active chemicals among Black women.

Reconnection of cysteine in reduced hair with alkylene dimaleates via thiol-Michael click chemistry

OBJECTIVES

Conventional hair permanent waving (PW) and permanent straightening processes typically involve two steps: reduction, for breaking -S-S- bond in cystine into cysteine and oxidation for -S-S- bond reconnection. However, it is known that the hair incurs damage during the oxidation step. In this work, we proposed a novel strategy to reconnect reduced disulfide bonds in hair via the thiol-Michael click reaction, by using a symmetric Michael reagent.

METHODS

Virgin black Chinese hair was reduced using 8% wt thioglycolic acid and employed as model hair containing a high content of broken disulfide bonds. The reduced hair was treated with 1,4-n-butylene dimaleate. Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to verify the chemical changes occurred in untreated and treated hair fibre. Single-fibre mechanical properties and thermal properties of the hair were evaluated using tensile testing and differential scanning calorimetry (DSC), respectively.

RESULTS

The 1,4-n-butylene dimaleate could reconnect free thiol groups generated by disulfide bond reduction via thiol-Michael click reaction and significantly improve the mechanical strength of hair compared to that of the reduced hair. Secondary conformational resolution analysis of FT-IR results revealed that the content of α-helix structure could be restored after treatment with 1,4-n-butylene dimaleate. The intermolecular forces established by the newly generated C-S bonds compensate the broken disulfide bonds and enhance the fracture strength of the hair compared to that of reduced hair. Michael reagents of similar structure also showed similar performance in restoring the mechanical properties of reduced hair.

CONCLUSIONS

Our data suggest that 1,4-n-butylene dimaleate can restore the mechanical properties of reduced hair by reconnecting reduced disulfide bonds and restoring the secondary conformation of hair keratin.

Boundary Lubrication Performance of Polyelectrolyte-Surfactant Complexes on Biomimetic Surfaces

Aqueous mixtures of oppositely charged polyelectrolytes and surfactants are useful in many industrial applications, such as shampoos and hair conditioners. In this work, we investigate the friction between biomimetic hair surfaces in the presence of adsorbed complexes formed from cationic polyelectrolytes and anionic surfactants in an aqueous solution. We apply nonequilibrium molecular dynamics (NEMD) simulations using the coarse-grained MARTINI model. We first developed new MARTINI parameters for cationic guar gum (CGG), a functionalized, plant-derived polysaccharide. The complexation of CGG and the anionic surfactant sodium dodecyl sulfate (SDS) on virgin and chemically damaged biomimetic hair surfaces was studied using a sequential adsorption approach. We then carried out squeeze-out and sliding NEMD simulations to assess the boundary lubrication performance of the CGG-SDS complex compressed between two hair surfaces. At low pressure, we observe a synergistic friction behavior for the CGG-SDS complex, which gives lower shear stress than either pure CGG or SDS. Here, friction is dominated by viscous dissipation in an interfacial layer comprising SDS and water. At higher pressures, which are probably beyond those usually experienced during hair manipulation, SDS and water are squeezed out, and friction increases due to interdigitation. The outcomes of this work are expected to be beneficial to fine-tune and screen sustainable hair care formulations to provide low friction and therefore a smooth feel and reduced entanglement.

Quantification of p-Phenylenediamine in Hair Dyes and Health Risk Implications in the UAE: Describing Discordances Between Regulations and Real-Life Practices

BACKGROUND

p-Phenylenediamine (PPD) has been used over the past five decades as a primary precursor in the production of oxidative hair dyes. Numerous health dangers are associated with the short- and long-term use of PPD, raising concerns about its safety. For instance, mounting data suggests that PPD is linked to dermatitis and allergy cases.

OBJECTIVE

To quantify the PPD content in hair dyes by measuring the PPD concentration after mixing the ingredients of commercial hair dyes.

METHODS

A total of 290 permanent hair dyes were tested. RP-HPLC-DAD analysis was performed to determine and quantify the PPD content.

RESULTS

The estimated mean of the PPD limit was 0.89 (95% CI [0.81-0.96]). Of the 290 tested hair dyes, 7.2% (n = 21) exceeded the recommended PPD concentration after mixing. Significantly more hair dyes manufactured in India and China had a PPD content exceeding 2% after mixing compared to dyes from other regions (P = 0.001). Moreover, hair dyes manufactured in India and the UAE were more likely to have incomplete descriptions of the conditions of use and warnings on the label (P = 0.002).

CONCLUSION

The effectiveness of the current regulations relevant to these products should be reevaluated. Moreover, through the use of good manufacturing procedures (GMPs), research, and the reporting of adverse reactions, hair dyes should be subjected to better control and monitoring in terms of their safety and quality.

Transparent silicone-free shampoo containing proteins with strong hair conditioning properties

OBJECTIVE

With the constant upgrading of healthcare concepts, silicone-free hair products have attracted more attention among consumers. In the present study, transparent silicone-free shampoo containing proteins was successfully fabricated by mixing mild non-sulphate surfactants, compound cationic conditioners, natural silicone oil substitutes, protein conditioners, thickeners, and other auxiliary ingredients. The effects of the type of surfactants, hair conditioners and thickeners, the type and content of proteins, and the mass ratio of compound proteins on the hair foaming performance, hair grooming performance, and penetration performance were investigated.

METHODS

The basic formulation framework for transparent silicone-free shampoo was established at first. Then, various hydrolyzed proteins were further added to the basic formulation in the form of single use or compound use to prepare transparent silicone-free shampoo containing different proteins. The morphology of hair samples and penetration of protein in hair were evaluated with a scanning electron microscope and laser confocal fluorescence microscopy, respectively. And the hair grooming performance was also determined by a dynamic combing tester.

RESULTS

The compound proteins of Croquat WKP PE-LQ-WD and Gluadin® Kera-PLM with mass ratios of 1:9 and 1:1 at 2 wt% total protein content added to the silicone-free shampoo brought a higher contact angle and a lower frictional coefficient than commercial silicone-free shampoo without proteins. In addition, the compound proteins also have the dual effect of adsorbing the hair surface and penetrating deep into the interior of the hair.

CONCLUSION

The combination of cationic modified hydrolyzed protein (e.g., Croquat WKP PE-LQ-WD) and hydrolyzed protein with low molecular weight (e.g., Gluadin® Kera-P LM) at an appropriate mass ratio exhibited a strong synergistic effect on hair conditioning properties. It could provide a significant reference for developing silicone-free hair products with more benefits.

Hair fixative traces on footwear - Establishing a link between footwear and the victim's hair after kicks to the head

Kicking a person laying on the floor in the head is a crime whose forensic investigation could profit from additional microtraces capable of linking a suspected footwear, and by extension its owner, to the victim and their injuries. The transfer of hair fixatives (hair gel, hair wax, hair spray, hair foam, etc.) represents such a trace and was consequently practically evaluated throughout this study. This study consists of two parts: The first part, the differentiation study, encompasses the visual, and instrumental analysis of a variety of different hair fixatives to determine their analysability and differentiation potential. The visual examination was conducted using alternate light sources and filter lenses. Subsequently, the instrumental analysis was carried out, whereby the focus lay on Fourier Transform Infra-red (FT-IR) spectroscopy and Raman spectroscopy. The second part is comprised of different experiments including a test-transfer and pendulum experiments to assess the process and the potential variables of the transfer of hair fixative traces between hair and fabric shoes during a kick. This helped to determine the effect of the kick strength and the behaviour of differing hair products. Retrieval methods to secure hair fixative traces of footwear and from the hair of a victim were developed. These were subsequently tested out on an acute case example..

Recent Progress in Hair Science and Trichology

Hair is important to our appearance as well as to protect our heads. Human hair mainly consists of proteins (80-85%), melanin pigments (0-5%), water (10-13%), and lipids (1-6%). The physicochemical properties of hair have been studied for over 100 years. However, they are not yet thoroughly understood. In this review, recent progress and the latest findings are summarized from the following three perspectives: structural characteristics, delivery and distribution of active ingredients, and hair as a template. The structural characteristics of hair have been mainly investigated by microscopic and/or spectroscopic techniques such as atomic force microscopy integrated with infrared spectroscopy (AFM-IR) and rheological measurements. The distribution of active ingredients has been generally evaluated through techniques such as nanoscale secondary ion mass spectrometry (NanoSIMS). And finally, attempts to explore the potential of hair to be used as a substrate for flexible device fabrication will be introduced.

Trends in biopolymer science applied to cosmetics

The term biopolymer refers to materials obtained by chemically modifying natural biological substances or producing them through biotechnological processes. They are biodegradable, biocompatible and non-toxic. Due to these advantages, biopolymers have wide applications in conventional cosmetics and new trends and have emerged as essential ingredients that function as rheological modifiers, emulsifiers, film-formers, moisturizers, hydrators, antimicrobials and, more recently, materials with metabolic activity on skin. Developing approaches that exploit these features is a challenge for formulating skin, hair and oral care products and dermatological formulations. This article presents an overview of the use of the principal biopolymers used in cosmetic formulations and describes their sources, recently derived structures, novel applications and safety aspects of the use of these molecules.

Bioactive Compound-Loaded Nanocarriers for Hair Growth Promotion: Current Status and Future Perspectives

Hair loss (alopecia) has a multitude of causes, and the problem is still poorly defined. For curing alopecia, therapies are available in both natural and synthetic forms; however, natural remedies are gaining popularity due to the multiple effects of complex phytoconstituents on the scalp with fewer side effects. Evidence-based hair growth promotion by some plants has been reported for both traditional and advanced treatment approaches. Nanoarchitectonics may have the ability to evolve in the field of hair- and scalp-altering products and treatments, giving new qualities to hair that can be an effective protective layer or a technique to recover lost hair. This review will provide insights into several plant and herbal formulations that have been reported for the prevention of hair loss and stimulation of new hair growth. This review also focuses on the molecular mechanisms of hair growth/loss, several isolated phytoconstituents with hair growth-promoting properties, patents, in vivo evaluation of hair growth-promoting activity, and recent nanoarchitectonic technologies that have been explored for hair growth.

Effects of surfactant adsorption on the wettability and friction of biomimetic surfaces

The properties of solid-liquid interfaces can be markedly altered by surfactant adsorption. Here, we use molecular dynamics (MD) simulations to study the adsorption of ionic surfactants at the interface between water and heterogeneous solid surfaces with randomly arranged hydrophilic and hydrophobic regions, which mimic the surface properties of human hair. We use the coarse-grained MARTINI model to describe both the hair surfaces and surfactant solutions. We consider negatively-charged virgin and bleached hair surface models with different grafting densities of neutral octadecyl and anionic sulfonate groups. The adsorption of cationic cetrimonium bromide (CTAB) and anionic sodium dodecyl sulfate (SDS) surfactants from water are studied above the critical micelle concentration. The simulated adsorption isotherms suggest that cationic surfactants adsorb to the surfaces via a two-stage process, initially forming monolayers and then bilayers at high concentrations, which is consistent with previous experiments. Anionic surfactants weakly adsorb via hydrophobic interactions, forming only monolayers on both virgin and medium bleached hair surfaces. We also conduct non-equilibrium molecular dynamics simulations, which show that applying cationic surfactant solutions to bleached hair successfully restores the low friction seen with virgin hair. Friction is controlled by the combined surface coverage of the grafted lipids and the adsorbed CTAB molecules. Treated surfaces containing monolayers and bilayers both show similar friction, since the latter are easily removed by compression and shear. Further wetting MD simulations show that bleached hair treated with CTAB increases the hydrophobicity to similar levels seen for virgin hair. Treated surfaces containing CTAB monolayers with the tailgroups pointing predominantly away from the surface are more hydrophobic than bilayers due to the electrostatic interactions between water molecules and the exposed cationic headgroups.

Dilution-Induced Deposition of Concentrated Binary Mixtures of Cationic Polysaccharides and Surfactants

This work investigates the effect of dilution on the phase separation process of binary charged polysaccharide-surfactant mixtures formed by two cationic polysaccharides and up to four surfactants of different nature (anionic, zwitterionic, and neutral), as well as the potential impact of dilution-induced phase separation on the formation of conditioning deposits on charged surfaces, mimicking the negative charge and wettability of damaged hair fibers. The results obtained showed that the dilution behavior of model washing formulations (concentrated polysaccharide-surfactant mixtures) cannot be described in terms of a classical complex precipitation framework, as phase separation phenomena occur even when the aggregates are far from the equilibrium phase separation composition. Therefore, dilution-enhanced deposition cannot be predicted in terms of the worsening of colloidal stability due to the charge neutralization phenomena, as common phase separation and, hence, enhanced deposition occurs even for highly charged complexes.

A comparison of dyeing efficacy between hair-oxidation-based and hair-coating-based shampoos for the treatment of gray hair

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.

Estimating Scalp Moisture in a Hat Using Wearable Sensors

Hair quality is easily affected by the scalp moisture content, and hair loss and dandruff will occur when the scalp surface becomes dry. Therefore, it is essential to monitor scalp moisture content constantly. In this study, we developed a hat-shaped device equipped with wearable sensors that can continuously collect scalp data in daily life for estimating scalp moisture with machine learning. We established four machine learning models, two based on learning with non-time-series data and two based on learning with time-series data collected by the hat-shaped device. Learning data were obtained in a specially designed space with a controlled environmental temperature and humidity. The inter-subject evaluation showed a Mean Absolute Error (MAE) of 8.50 using Support Vector Machine (SVM) with 5-fold cross-validation with 15 subjects. Moreover, the intra-subject evaluation showed an average MAE of 3.29 in all subjects using Random Forest (RF). The achievement of this study is using a hat-shaped device with cheap wearable sensors attached to estimate scalp moisture content, which avoids the purchase of a high-priced moisture meter or a professional scalp analyzer for individuals.

Comparison on Quality Performance of Human Hair Types with Herbal Oils (Grape Seed/Safflower Seed/Rosehip) by Analysis Techniques

Hair is exposed to harmful factors such as sunlight, pollution, cosmetic applications, and cleaning every day. With lost moisture, the hair is worn out, loses shine, and exhibits color changes in the case of dyed hair. In this study, the effects of herbal oils on hair were investigated by comparing the properties with measurements. Three different types of hair were used: natural (unprocessed), damaged, and dyed hair. After washing hair with a base shampoo, herbal oils were applied, and brightness, color changes, elasticity, and breaking points were examined. Safflower seed oil, grape seed oil, and rosehip oil were applied to the samples. It was tried to regain the properties that have decreased as a result of shampoo application in the hair with the applied oils. The highest gloss was observed with grape seed oil, and according to color change calculations, the best result was seen with safflower seed oil. Tensile-strain testing was performed for all samples, and rosehip oil gave the best results. The changes in hair fractures were examined with a scanning electron microscope, and grape seed oil was the best for all hair types. When all analyses were evaluated, the best performing herbal oil was grape seed oil. All analysis results showed that herbal oils can be used in the cosmetics industry with different applications.

On Hair Care Physicochemistry: From Structure and Degradation to Novel Biobased Conditioning Agents

Hair is constantly exposed to various adverse external stimuli, such as mechanical or thermal factors, that may cause damage or cause it to lose its shine and smooth appearance. These undesirable effects can be minimized by using hair conditioners, which repair the hair and restore the smooth effect desired by the consumer. Some of the currently used conditioning agents present low biodegradability and high toxicity to aquatic organisms. Consumers are also becoming more aware of environmental issues and shifting their preferences toward natural-based products. Therefore, developing novel, sustainable, natural-based derivatives that can act as conditioning agents in hair care products and thus compete with the traditional systems obtained from non-renewable sources is highly appealing. This paper presents the key physicochemical aspects of the hair conditioning process, including hair structure and degradation, and reviews some of the new alternative conditioning agents obtained from natural resources.

A community-based study of hair care practices, scalp disorders and psychological effects on women in a Suburban town in Southwest Nigeria

Introduction

The scalp hairs on an average African is dry with low tensile strength and a tendency to break easily. This is mostly due to poor penetration of the natural oils on the scalp and the very curly hair texture. Various techniques developed to manage African hair are associated with certain hair and scalp disorders and are sources of distress.

Objectives

This was a cross-sectional survey to compare natural African hair and chemically processed (relaxed) hair to determine the effect of hair care and grooming practices on common scalp disorders and the psychological effect in Nigerian women.

Subjects and Methods

Questionnaires were administered to women at the market, churches and outreaches with many women in attendance to document the hair grooming practices, common scalp symptoms and psychological effects experienced. They were also examined for the presence of seborrhoeic dermatitis and traction alopecia.

Results

The study involved 452 women (62.17%) with relaxed hair and 275 women (37.83%) with natural (untreated) hair. Women with relaxed hair experienced significantly more flaking of the scalp (P = 0.046, x² = 6.16), hair breakage (P = 0.023, x² = 11.35) and hair loss (P = 0.020, x² = 7.87) than those with natural hair. The most common psychological effects of hair scalp disorders in all participants were feeling of uneasiness 142 (19.5%), frustration 49 (6.7%), poor body image 40 (5.5%) and anger 38 (5.2%). Significantly more women with relaxed hair experienced moderate hair loss from traction than women with natural hair (P = 0.014, x² = 8.52).

Conclusion

Nigerian women experienced clinical and psychological distress consequent to their hair grooming practices. Individuals with relaxed hair had more physical symptoms, hair loss and psychological disturbances than those with natural hair.

Hair Aging and Hair Disorders in Elderly Patients

Hair loss in elderly patients is a common complaint. It can be related to different conditions that affect patients' quality of life and represents a challenge for dermatologists. It affects both men and women during the aging process with an estimated percentage of balding after 65 years of age of 53% and 37%, respectively. Androgenetic alopecia, frontal fibrosing alopecia, senile alopecia, and erosive pustular dermatosis of the scalp are the hair diseases most frequently described in this age group. The objective of this review is to summarize the current knowledge about alopecia affecting elderly patients, differentiating between chronological hair aging signs and pathological changes, to help clinicians, offer an adequate management of these disorders to their patients.

Protection of hair color with pomegranate peel extract-loaded liposomal formulation: Preparation, characterization, and ex-vivo activity studies

BACKGROUND

Pomegranate peel extract is known as a powerful antioxidant and due to preventing oxidation, it can reduce color change of dyed hair after washing. Liposomes are vesicular systems that include lipids and can form a film on hair fibers. Delivery system and active agent have a synergistic effect on protecting hair color and reducing dyeing frequency.

AIMS

This study aimed to prepare liposomes suspension as an innovative formulation of pomegranate peel extract to reduce hair color changing.

METHODS

Pomegranate peel extract-loaded liposomes were prepared with lipidic film hydration method. The characterizations of formulations (F1 and F2) were defined by several parameters. The pH, particle size, polydispersity index, zeta potential, microscopical image, loading capacity (LC), and encapsulation efficiency (EE) of formulations were determined. The antioxidant capacity of formulations and actives were tested. The effect of formulations on hair color change was shown with ex-vivo studies.

RESULTS

The results showed that cholesterol influenced particle size, zeta potential, and antioxidant capacity. The particle sizes of formulations were 217.71 ± 6.74 nm and 577.5 ± 1.41 nm for F1 and F2, respectively. F2 formulation had better results for zeta potential (33.8 mV) while F1 was neutral. Morphologic images confirmed vesicular structure or liposomes. The EE was found higher for F2 than F1 (F1: 57.14 and F2: 78.69). Antioxidant studies confirmed that active substance and the vesicular system had a synergistic effect on protection from oxidation. Selected formulation reduced hair color change as shown in ex-vivo tests.

CONCLUSION

Pomegranate peel extract-loaded liposomes were designed for hair color protection. It was shown with this study that prepared formulations have a good color protection on hair fibers due to antioxidant properties of pomegranate peel extract and film forming effect of liposomal formulations. According to results, prepared liposomal formulations may serve as a good alternative for reducing dyeing frequency and protecting hair fibers.

Surface Activity of Surfactant–Polyelectrolyte Mixtures through Nanoplasmonic Sensing Technology

Deposition plays an important role in the active delivery and efficiency of hair and skin formulations since it allows active compounds to interact with surfaces in order to achieve the product’s desired performance characteristics. Therefore, it is essential to study the surface activity and behavior of certain compounds that are frequently used in cosmetic and pharmaceutical formulations in order to understand how they interact with relevant biological surfaces, such as hair and skin. We chose to study the surfactants and conditioning agents utilized in the formulation of conditioning shampoos, which are usually designed to be able to achieve the deposition of these substances on the hair and scalp to provide lubrication and better conditioning for hair fibers, facilitating detangling and providing a better feel. In this study, cationic polymer and salt fractions were varied to obtain eighteen different conditioning shampoo formulations in which the deposition was measured by utilizing a nanoplasmonic sensing technology instrument. Moreover, a wet combing test was performed for each of the formulations to investigate if there was any correlation between the combing force and the surface deposition. The complete study was performed using a sustainable anionic surfactant in order to compare the results with those obtained from the traditional formulations.

4-Chloro-1,2-phenylenediamine induced structural perturbation and genotoxic aggregation in human serum albumin

4-Chloro-1,2-phenylenediamine (4-Cl-OPD) is a halogenated aromatic diamine used as a precursor in permanent hair color production. Despite its well-documented mutagenic and carcinogenic effects in various in vitro and in vivo models, its role in fibrillar aggregate formation and their genotoxic effect in therapeutic proteins has received less attention. The significance of human serum albumin (HSA) arises from its involvement in bio-regulatory and transport processes. HSA misfolding and aggregation are responsible for some of the most frequent neurodegenerative disorders. We used various complementary approaches to track the formation of amyloid fibrils and their genotoxic effect. Molecular dynamics study demonstrated the complex stability. The impact of 4-Cl-OPD on the structural dynamics of HSA was confirmed by Raman spectroscopy, X-ray diffraction, HPLC and SDS-PAGE. Fibrilllar aggregates were investigated using Congo red assay, DLS, and SEM. The genotoxic nature of 4-Cl-OPD was confirmed using plasmid nicking assay and DAPI staining, which revealed DNA damage and cell apoptosis. 4-Cl-OPD provides a model system for studying fibrillar aggregation and their genotoxic potential in the current investigation. Future studies should investigate the inhibition of the aggregation/fibrillation process, which may yield valuable clinical insights.

4-Chloro-1,2-phenylenediamine induced structural perturbation and genotoxic aggregation in human serum albumin

4-Chloro-1,2-phenylenediamine (4-Cl-OPD) is a halogenated aromatic diamine used as a precursor in permanent hair color production. Despite its well-documented mutagenic and carcinogenic effects in various in vitro and in vivo models, its role in fibrillar aggregate formation and their genotoxic effect in therapeutic proteins has received less attention. The significance of human serum albumin (HSA) arises from its involvement in bio-regulatory and transport processes. HSA misfolding and aggregation are responsible for some of the most frequent neurodegenerative disorders. We used various complementary approaches to track the formation of amyloid fibrils and their genotoxic effect. Molecular dynamics study demonstrated the complex stability. The impact of 4-Cl-OPD on the structural dynamics of HSA was confirmed by Raman spectroscopy, X-ray diffraction, HPLC and SDS-PAGE. Fibrilllar aggregates were investigated using Congo red assay, DLS, and SEM. The genotoxic nature of 4-Cl-OPD was confirmed using plasmid nicking assay and DAPI staining, which revealed DNA damage and cell apoptosis. 4-Cl-OPD provides a model system for studying fibrillar aggregation and their genotoxic potential in the current investigation. Future studies should investigate the inhibition of the aggregation/fibrillation process, which may yield valuable clinical insights.

Emerging trends of nanotechnology in advanced cosmetics

The cosmetic industry is dynamic and ever-evolving. Especially with the introduction and incorporation of nanotechnology-based approaches into cosmetics for evincing novel formulations that confers aesthetic as well as therapeutic benefits. Nanocosmetics acts via numerous delivery mechanisms which involves lipid nanocarrier systems, polymeric or metallic nanoparticles, nanocapsules, dendrimers, nanosponges,etc. Each of these, have particular characteristic properties, which facilitates increased drug loading, enhanced absorption, better cosmetic efficacy, and many more. This article discusses the different classes of nanotechnology-based cosmetics and the nanomaterials used for their formulation, followed by outlining the categories of nanocosmetics and the scope of their utility pertaining to skin, hair, nail, lip, and/or dental care and protection thereof. This review also highlights and discusses about the key drivers of the cosmetic industry and the impending need of corroborating a healthy regulatory framework, refocusing attention towards consumer needs and trends, inculcating sustainable techniques and tenets of green ecological principles, and lastly making strides in nano-technological advancements which will further propel the growth of the cosmetic industry.

Physico-chemical and thermal characteristics of sandy loam soils contaminated by single and mixed pollutants (mineral and vegetable oils)

Samples of contaminated top soil (0-30 cm) and uncontaminated soil (control) from two locations in Precambrian basement complex area were analyzed to assess the effects of single and mixed oil contaminants on the physico-chemical and thermal properties of soils. Pearson's correlation and analysis of variance (ANOVA) were used to study the interrelationships of the studied parameters as well as variation of studied soil characteristics under the different oil contaminants, respectively. Results showed insignificant impact of pollutant(s) on the textural class of contaminated soils. The highest and lowest mean soil resistivity (SR) values were found in petrol-contaminated and mixed surfactants (shampoo + conditioner) -contaminated soils, respectively. The least values of mean specific heat capacity (SHC), heat capacity (HC), and soil water diffusivity (SWD) were found in soils contaminated by mixed surfactants-contaminants. However, mixed mineral oils (petrol + diesel + engine oil) and mixed vegetable oils (palm oil + groundnut oil) had mean SHC values lower than those of control soils at the two sampling locations. The mixed surfactants-polluted soil is characterized by lowest mean bulk density (BD) and highest mean gravimetric water content (GWC) while lowest mean GWC and highest mean SWD characterized engine oil-contaminated soils. The analysis of variance (ANOVA) result revealed significant variation in % sand at 5% level (p < 0.05) for petroleum-derived contaminants but no significant differences in mean values of all analyzed soil properties under vegetable oil contaminants.

Study of P-Phenylenediamine (PPD) Concentrations after Hair Dye Mixing: A Call for Safety Reassessment

Para-phenylenediamine (PPD) is a chemical that is widely used in hair dyes. Multiple safety and regulatory agencies have categorized PPD as a potent sensitizer. In addition, PPD has carcinogenicity and genotoxicity attributes and, consequently, it is regulated at a maximal concentration of 2.0%. The aim of this study was to test whether the limit for PPD is surplus, and hence whether the consumer may be exposed to unnecessarily PPD levels. Experimentally, the analysis of PPD was performed using HPLC, where method validation and an inter-laboratory comparison test (ILC) were conducted to evaluate method performance. Thirty-three commercial products were analyzed, and five products were chosen to study the unconsumed PPD. Successfully, the implemented method confirmed its suitability and validity for the determination of PPD. For ILC results, PPD levels were 0.97 ± 0.04% and 0.92 ± 0.02%, quantified by our laboratory and an accredited laboratory, respectively. For all products, the initial concentration (T0) of PPD was lower than the regulatory limit. After 45 min, the content of PPD significantly reduced compared to T0. One product showed unconsumed PPD to be as high as 96% following the recommended dyeing time. In conclusion, the existence of high levels of unreacted PPD increases the likelihood of allergic events and elevates the risk of PPD-related chemicals. Collaborative efforts between industries, regulatory bodies, and health-related decision makers are deemed necessary to establish safe concentrations for PPD.

Nanomaterials in hair care and treatment

Hair care and treatment has evolved significantly through the years as new formulations are continuously being explored in an attempt to meet the demand in cosmetic and medicinal fields. While standard hair care procedures include hair washing, aimed at hair cleansing and maintenance, as well as hair dyeing and bleaching formulations for hair embellishment, modern hair treatments are mainly focused on circumventing hair loss conditions, strengthening hair follicle properties and treat hair infestations. In this regard, active compounds (ACs) included in hair cosmetic formulations include a vast array of hair cleansing and hair dye molecules, and typical hair treatments include anti-hair loss ACs (e.g. minoxidil and finasteride) and anti-lice ACs (e.g. permethrin). However, several challenges still persist, as conventional AC formulations exhibit sub-optimal performance and some may present toxicity issues, calling for an improved design of formulations regarding both efficacy and safety. More recently, nano-based strategies encompassing nanomaterials have emerged as promising tailored approaches to improve the performance of ACs incorporated into hair cosmetics and treatment formulations. The interest in using these nanomaterials is based on account of their ability to: (1) increase stability, safety and biocompatibility of ACs; (2) maximize hair affinity, contact and retention, acting as versatile biointerfaces; (3) enable the controlled release of ACs in both hair and scalp, serving as prolonged AC reservoirs; besides offering (4) hair follicle targeting features attending to the possibility of surface tunability. This review covers the breakthrough of nanomaterials for hair cosmetics and hair treatment, focusing on organic nanomaterials (polymer-based and lipid-based nanoparticles) and inorganic nanomaterials (nanosheets, nanotubes and inorganic nanoparticles), as well as their applications, highlighting their potential as innovative multifunctional nanomaterials towards maximized hair care and treatment. STATEMENT OF SIGNIFICANCE: This manuscript is focused on reviewing the nanotechnological strategies investigated for hair care and treatment so far. While conventional formulations exhibit sub-optimal performance and some may present toxicity issues, the selection of improved and suitable nanodelivery systems is of utmost relevance to ensure a proper active ingredient release in both hair and scalp, maximize hair affinity, contact and retention, and provide hair follicle targeting features, warranting stability, efficacy and safety. This innovative manuscript highlights the advantages of nanotechnology-based approaches, particularly as tunable and versatile biointerfaces, and their applications as innovative multifunctional nanomaterials towards maximized hair care and treatment.

Study of the Dilution-Induced Deposition of Concentrated Mixtures of Polyelectrolytes and Surfactants

Mixtures of polyelectrolytes and surfactants are commonly used in many technological applications where the challenge is to provide well-defined modifications of the surface properties, as is the case of washing formulations in cosmetics. However, if contemporary experimental and theoretical methods can provide insights on their behavior in concentrated formulations, less is known on their behavior under practical use conditions, e.g., under dilution and vectorization of deposits. This makes it difficult to make predictions for specific performance, as, for example, good hair manageability after a shampoo or a comfortable sensorial appreciation after a skin cleanser. This is especially important when considering the formulation of new, more eco-friendly formulations. In this work, a detailed study of the phase separation process induced by dilution is described, as well as the impact on the deposition of conditioning material on negatively charged surfaces. In order to gain a more detailed physical insight, several polyelectrolyte–surfactant pairs, formed by two different polymers and five surfactants that, although non-natural or eco-friendly, can be considered as models of classical formulations, have been studied. The results evidenced that upon dilution the behavior, and hence its deposition onto the surface, cannot be predicted in terms of the behavior of simpler pseudo-binary (mixtures of a polymer and a surfactant) or pseudo-ternary mixtures (two polymers and a surfactant). In many cases, phase separation was observed for concentrations similar to those corresponding to the components in some technological formulations, whereas the latter appeared as monophasic systems. Therefore, it may be assumed that the behavior in multicomponent formulations is the result of a complex interplay of synergistic interactions between the different components that will require revisiting when new, more eco-sustainable ingredients are considered.

Practical Approach to Hair Loss Diagnosis

Hair loss is one of the common complaints encountered in a cosmetic practice. Evaluating a patient with hair loss requires a thorough understanding of the various causes of hair loss and practical knowledge in hair cosmetics and hair styling procedures. A systematic approach in hair loss evaluation helps the treating physician in arriving at a diagnosis. Various bedside tests and advent of trichoscopy has empowered the physician in arriving at a diagnosis. This article aims to provide the physician a systematic approach in evaluating a patient with hair loss.

Effects of chemical straighteners on the hair shaft and scalp: a review

Background

The effects of chemical straighteners on the scalp and hair shaft are not fully known, although such substances are widely used. Hair straightening became popular in Brazil with the use of formaldehyde and its derivatives, despite the prohibition by the current legislation.

Objective

To identify changes in hair shaft and scalp caused by the use of chemical straighteners.

Methods

A search was performed using keywords in three databases from 03/16/2020 to 05/20/2020, with publications between the years 2000 to 2020. After applying the inclusion and exclusion criteria, 33 articles were selected for review.

Results

In some studies, hair relaxers were associated with eczema, desquamation, pain, burns, and inflammation in the scalp. Hair loss, damage to the shaft, alteration in the color of the hairs and in the composition of their amino acids were observed. Findings are variable across the studies.

Study limitations

The search was restricted to three databases, in two languages, different study designs were accepted.

Conclusions

Straightening techniques can have side effects, including scalp inflammation, damage to the shaft, and hair loss. Its long-term effects remain unknown and further studies are necessary.

A method to measure oil penetration into hair and correlation to tensile strength

Aim:

The aim of this study is to identify a new method to measure oil penetration into hair, compare penetration ability of two types of oil: Type 3 hair oil and coconut oil into the hair shaft and explore its correlation to a physical property of hair, tensile strength.

Materials and Methods:

The study utilizes the measurements of two parameters, thickness, and cohesive force to define penetration of oil. The hypothesis was that an increase in hair fiber thickness along with reduction in cohesive force would indicate higher penetration of oil into the hair strand. The tensile strength of hair was then determined by measuring the behavior of treated hair strands while an axial stretching load was applied.

Results:

In experiment of hair thickness measurement, there was a significant increase in the hair fiber thickness post oil application in both the test oils as compared to baseline (untreated control). However, this increase was higher in hair swatches treated with Type 3 hair oil. For cohesive force measurement, significantly lower force was required for hair swatches treated with Type 3 hair oil when compared to coconut oil. For tensile strength, both test oils exhibited increase versus baseline but increase in tensile strength was significantly more with type 3 hair oil when compared to coconut oil.

Conclusions:

The present study shows that conjoint assessment of hair thickness and cohesive force post oil application can be a suitable method to indicate the extent of oil penetration into the hair. Overall, the study indicated the positive influence of oil penetration on hair strength.

Psoriasiform skin reaction due to Brazilian keratin treatment: A clinical-dermatoscopic study of 43 patients

Introduction:

Hair straightening products like the Brazilian Keratin Treatment (BKT) contain high concentrations of formaldehyde, and its use is associated with adverse effects. In 2016, seven cases of eczema-like psoriasiform skin reaction secondary to BKT were described for the first time. We aim to investigate the clinical characteristics and dermatoscopic findings of patients with psoriasiform skin reactions due to BKT.

Materials and Methods:

A cross-sectional study was performed from October 2017 to June 2020. Patients who developed erythema and scales on the scalp following the use of BKT were included. Age, sex, number of BKTs, time elapsed between BKT and the skin reaction, pull test, and dermatoscopic findings were investigated. Descriptive and inferential statistics were used.

Results:

We found 43 patients with a mean age of 35 ± 10 years, predominantly females in 42 (98%) cases. The mean number of BKTs was 2 ± 2. The mean length of time elapsed to present the reaction was 12 ± 17 months and this was related to the number of BKTs (P = 0.01). The pull test was positive in 37 (86%) patients. The most frequent dermatoscopic findings were perifollicular scales in 42 (98%), red patches in 35 (81%), and peripilar desquamation resembling the outer skin of an onion bulb in 32 (74%).

Conclusion:

Hair straightening products are widely used and the psoriasiform skin reaction that develops afterward might be underdiagnosed. It is important to investigate the background of BKT in conjunction with the clinical and dermatoscopic findings suggestive of this cutaneous reaction.

Mapping the Chemistry of Hair Strands by Mass Spectrometry Imaging-A Review

Hair can record chemical information reflecting our living conditions, and, therefore, strands of hair have become a potent analytical target within the biological and forensic sciences. While early efforts focused on analyzing complete hair strands in bulk, high spatial resolution mass spectrometry imaging (MSI) has recently come to the forefront of chemical hair-strand analysis. MSI techniques offer a localized analysis, requiring fewer de-contamination procedures per default and making it possible to map the distribution of analytes on and within individual hair strands. Applying the techniques to hair samples has proven particularly useful in investigations quantifying the exposure to, and uptake of, toxins or drugs. Overall, MSI, combined with optimized sample preparation protocols, has improved precision and accuracy for identifying several elemental and molecular species in single strands of hair. Here, we review different sample preparation protocols and use cases with a view to make the methodology more accessible to researchers outside of the field of forensic science. We conclude that—although some challenges remain, including contamination issues and matrix effects—MSI offers unique opportunities for obtaining highly resolved spatial information of several compounds simultaneously across hair surfaces.

The Use of Calcium Phosphates in Cosmetics, State of the Art and Future Perspectives

Calcium phosphates (CaPs) belong to a class of biomimetic materials widely employed for medical applications thanks to their excellent properties, such as biodegradability, biocompatibility and osteoinductivity. The recent trend in the cosmetics field of substituting potentially hazardous materials with natural, safe, and sustainable ingredients for the health of consumers and for the environment, as well as the progress in the materials science of academics and chemical industries, has opened new perspectives in the use of CaPs in this field. While several reviews have been focused on the applications of CaP-based materials in medicine, this is the first attempt to catalogue the properties and use of CaPs in cosmetics. In this review a brief introduction on the chemical and physical characteristics of the main CaP phases is given, followed by an up-to-date report of their use in cosmetics through a large literature survey of research papers and patents. The application of CaPs as agents in oral care, skin care, hair care, and odor control has been selected and extensively discussed, highlighting the correlation between the chemical, physical and toxicological properties of the materials with their final applications. Finally, perspectives on the main challenges that should be addressed by the scientific community and cosmetics companies to widen the application of CaPs in cosmetics are given.

Biotechnology of functional proteins and peptides for hair cosmetic formulations

Cosmetics procedures and products combined with environmental insults and daily routines induce irreversible changes in hair. As result of damage, the hair loses some of its properties like strength, elasticity, and smoothness. Recent studies revealed the positive effects of protein-based cosmetics in providing protection to hair. Additionally, these cosmetic products have also shown a great ability to modify hair fibers. We review the effect of protein-based cosmetic formulations on hair properties like color, scent, strength, shape, and volume, highlighting the potential of keratin-based particles and keratin-fusion proteins. In the future, incorporating multifunctional proteins and peptides in the development of alternative hair formulations will result in advanced, sustainable, ecofriendly cosmetic products with a great impact on the cosmetic industry.

Hair Cosmetics for the Hair Loss Patient

Medical professionals that treat patients with alopecia usually lack knowledge about hair cosmetics. Trichologists focus on hair cycling and growth problems and not on the hair shaft integrity. This may lead to abandon of the use of the prescribed treatment, such as topical minoxidil or to inadequate traumatic grooming habits that may jeopardize hair follicle health. Shampoos, hair dyes, and hair-straightening products may alter hair fiber structure, remove lipids, and elude protein. Hair procedures such as hair dying and straightening have side effects and health concerns, especially for pregnant women or sensitive hair and scalp patients. Hair breakage, follicle traction, frizz, contact dermatitis, and mutagenicity are possible side effects of hair cosmetics misuse. The proper use of hair care products may help to increase patients' adherence to alopecia treatments and avoid health problems related to inadequate application of hair cosmetics and procedures.

Influence of cosmetic hair treatments on hair of methamphetamine abuser: Bleaching, perming and coloring

Various cosmetic hair manipulations are known to interfere with the drug of abuse concentrations in hair. It is important to know the effects of cosmetic hair treatments as they may cause false-positive or false-negative results. The article aimed to investigate the effect of bleaching, perming, and dyeing treatment on the hair of methamphetamine（MA）abusers. The research results show that during the bleaching treatment, the content of MA in the hair is positively correlated with the degree of the treatment. Bleaching caused strong chemical degradation on MA, while perming exerted more a leaching out effect. Temporary dyes in single applications had only little effects on MA, Semi-permanent dyes can penetrate into the hair and exert a stronger matrix effect. The effect of permanent hair dye on the content of MA in hair mainly depends on the concentration of hydrogen peroxide.

An Adoptable Multi-Criteria Decision-Making Analysis to Select a Best Hair Mask Product-Extended Weighted Aggregated Sum Product Assessment Method

Hair masks (HMs) act as one of the solutions for most of the hair problems like dandruff, frizziness, breakage, premature- greying and so on. Due to its various benefits, HM products are acquiring more popularity among the individuals. As there are different varieties of HM products available in the market, the confusion arises in choosing a HM which suits the individual’s hair profile and causes less side effects. Here, we have employed multi-criteria decision-making (MCDM) combined with fuzzy set theory to obtain better results. We used the extended Weighted Aggregated Sum Product Assessment (WASPAS) method based on trapezoidal interval type-2 fuzzy set (TIT2FS) in this research paper to handle vagueness and complexity in real-world problems. For determining the objective weights of the criteria, we used the entropy method of weight finding. An example of selecting a hair mask product (HMP) among four alternatives based on five criteria is provided to illustrate the applicability of the proposed method. In comparison to other MCDM methods, the approach yielded more practical results. By doing a sensitive study, the method’s stability is also assessed.

Host factors that shape the bacterial community structure on scalp hair shaft

In this study, we performed 16S rRNA amplicon sequencing analysis of scalp hair shaft from 109 volunteers, who were surveyed using a questionnaire about daily scalp hair care, and employed multiple statistical analyses to elucidate the factors that contribute to the formation of bacterial community structures on scalp hair shaft. Scalp hair microbiota were found to be specific for each individual. Their microbiota were clearly divided into two clusters. Genus level richness of Pseudomonas (Ps) and Cutibacterium (Cu) contributed to the clusters. The clusters around Pseudomonas and Cutibacterium were named Ps-type and Cu-type, respectively. The host gender influenced the bacterial cell numbers of the major genera that included Cutibacterium, Lawsonella, Moraxella, and Staphylococcus on scalp hair shaft. In addition to host intrinsic factors, extrinsic factors such as hair styling and colouring affected the bacterial cell numbers of the major genera. These factors and chemical treatments, such as bleaching and perming, also affected the Ps-type to Cu-type ratios. These results suggest that bacterial community structures on scalp hair shaft are influenced by both intrinsic and extrinsic factors.