Permanent Waving Research Articles

The swelling behaviour of hair studied through the structural change of keratin protein during the permanent waving treatment

Filament of human hair is formed from α-keratin protein and its physical property is predominantly dominated by the structure of microfibril (also known as intermediate filaments (IF)). It is known that human hair is swollen by permanent waving (pw) treatment which consists of the reducing process and following oxidizing process, but a detail in the swelling behaviour remains still unclarified. The present work was devoted to the analysis of the swelling behaviour of hair through the structural change of IF during pw treatment, where 1.0 mol/L ammonium thioglycolate solution (pH 9.25) was employed as reducing reagent. The structure of IF was represented in terms of its microstructure, which is given by α-helix content in keratin chain, and its macrostructure, which is given by alignment of IF along human hair axis, and the structures were studied by SAXS and CP/MAS 13C NMR and others. It is shown that the microstructure and macrostructure of IF simultaneously start to change at an initial stage of the pw treatment without any induction period and both structures are sufficiently swollen at that stage. Furthermore, it is shown that the microstructure and macrostructure of IF is partly destructed by reducing treatment, but the destructed structures are considerably restored by following oxidizing treatment.

Analysis of the hydration water on the surface of human hair using a combination of infrared absorption vibrational spectroscopy and multivariate curve resolution

Modern society's keen regard for aesthetics made hair products an integral part of a multi‐billion‐dollar cosmetic industry. Hair care products (e.g., shampoos and conditioners) and chemical treatments (e.g., bleaching and permanent waving) result in various effects on the morphological attributes of hair. Generally, water adsorbed on the hair surface is known to significantly dictate the hair's mechanical characteristics (smoothness and friction), and hair's macroscopic wettability has been commonly used to indicate its surface properties. However, an approach to selectively characterize the hydration water in the hair surface is required to accurately understand the intermolecular events between the hair and its vicinal water. In this paper, we successfully obtained the infrared (IR) absorption spectra of the hydration water of human hair. We employed the multivariate curve resolution‐alternating least square (MCR‐ALS) method to separate the hydration and bulk water spectra from the whole spectra. Comparing the IR spectra of the hydration water of chemically untreated and bleached hair samples, we conclude that water molecules form strong hydrogen bonds with the bleached hair surface due to the destruction of the hair's hydrophobic outer layer and the consequent formation of hydrophilic residues.

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

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. 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. 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. 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.

Analysis of Morphological Changes on the Hair Surface by Heat Perm Treatment Method

Frequent chemical treatments, such as dyeing and permanent waving, as well as the widespread use of heat-based hair styling devices, like flat irons and curling irons, can cause significant damage to hair fibers, leading to various adverse effects, such as dryness, breakage, split ends, and frizziness. Recently, there has been a trend towards using direct heat perms because they are time-saving, shorter in duration, and less complicated. However, as the damage to hair caused by direct perms increases, this study compares and analyzes the degree of damage to hair fibers caused by both direct heat perms and softening heat perms. Moreover, by comparing, analyzing, and evaluating the morphological changes to the hair surface and cross-section after each type of perm treatment based on hair condition, this study aims to objectively understand the effects of heat perms on hair and provide basic data for further research in this field.

Green chemistry method for hair strengthening and setting using visible light-mediated protein crosslinking

A clean and nontoxic one-step protein crosslinking reaction method induced by visible light was developed using eco-friendly chemicals, such as riboflavin phosphate (RFP), citric acid (CA), and polyols . In this study, oxygen radicals generated by blue light (BL)-irradiated RFP replace the conventional free thiol generatio step of the alkali condition. CA and polyol were used as crosslinkers and extenders , respectively, to enhance keratin crosslinking in hair. The new one-step crosslinking method was compared with the existing permanent hair waving treatment using thioglycolic acid (TGA). Compared to TGA treatment, the newly proposed crosslinking method induced minor damage to hair and keratin. In addition, the mechanical property changes were measured after crosslinking treatment on the hair. The tensile stress values and Young's moduli of the treated hair samples were approximately 1.3 and 2.2 times higher than untreated hair. The hair-setting effect was also confirmed by the changes in the radii of the hair fibers and the length of the hair tresses after crosslinking treatment. Therefore, we believe that the clean one-step crosslinking technology can be used to develop eco-friendly products for hair strengthening and setting. • Clean one-step crosslinking of keratin is effective in strengthening and setting hair. • Keratin crosslinking is induced by exposure to blue light in the presence of RFP. • Citric acid and polyols form extender acts as a linker for keratin crosslinking.

Smart and Sustainable Hair Products Based on Chitin-Derived Compounds

According to previous research studies, consumers worldwide are searching for new natural-oriented hair products that are both skin and environmentally friendly. Worldwide waste and air pollution, with the consequent environmental disasters, represent the greatest risk to human health and economy, further increased by the COVID-19 pandemic. Among others, non-biodegradable molecules are present in hair products (fossil-based additives, surfactants, etc.) and macromolecules (plastics). Plastics waste is considered the most serious problem, representing a forecast amount of 460 million tons per year by 2030, 12% of which is reused or recycled. Most plastics consumed, therefore, go to landfills and incineration, also if their recycling is considered an important driver of industrial profitability. Thus, the use of biopolymers represents an interesting alternative to produce biodegradable goods and tissues. After an introduction to the worldwide waste problem and the hair structure, the present review proposes the possibility to make biodegradable tissues that, realized by chitin nanofibrils and nano-lignin as natural polymers, may be used to produce an innovative and smart cosmetic hairline. Chitin-derived compounds are considered interesting polymers to produce non-woven tissues able to repair the hair damages provoked by the aggressiveness of both the environment and some aggressive cosmetic treatments, such as setting, bleaching, permanent waving, and oxidative coloring. The possible activity, that positively charged polymers such as chitin could have, has been speculated, interfering with the constitution and organization of the hair fibrils’ structure, which is negatively charged. The possibility of selecting biopolymers for their packaging is also discussed. Moreover, the use of these biopolymers, obtained from forestry-agro-food waste, may be of help to safeguard the further consumption of natural raw materials, necessary for future generations, also maintaining the earth’s biodiversity.

Brief descriptions of the principles of prominent methods used to study the penetration of materials into human hair and a review of examples of their use.

Consumers are attracted to the latest fashion trends and different looks. This drives the search for novel hair treatments. Some chemicals present in hair treatment products can penetrate the hair shaft. These materials can either nourish or injure the hair cortex. Different techniques have been used to investigate the mechanism of molecule penetration and the conditions under which penetration occurs. This article reviews the techniques applied for this purpose. Various microscopy techniques are used to capture clear and colourful images to determine the diffusion pathways and the exact location of the molecules under study. However, the laborious sample preparation often leads to sample destruction since cross-sectioning is often required. While various other techniques have been successfully used for investigating the penetration methods, most of these require different amounts of work to be put in for sample preparation and instrumentation. Several spectroscopic techniques have been used to study the penetration of the molecules because of the high levels of accuracy and the quick response time of these techniques. Moreover, the samples are not damaged during the investigation.

A Raman spectroscopic investigation of the mechanism of the reduction in hair with thioglycerol and the accompanying disulphide conformational changes.

The objective of our research was to investigate the reduction mechanism of thioglycerol (TG) on hair keratin fibres. The structure of cross-sections at various depths of virgin white human hair resulting from the permanent waving process with TG was directly analysed at the molecular level using Raman spectroscopy. Also, the penetration of TG for the cross-sectional samples dyed with methylene blue was observed by optical microscopy. The gauche-gauche-gauche (GGG) and gauche-gauche-trans (GGT) conformations of disulphide (-SS-) groups remarkably decreased, while the trans-gauche-trans (TGT) conformation increased by performing the reduction process with TG. In addition, the disconnected -SS- content at various depths of the hair sample reduced with TG adjusted to pH 9.0 with ammonia solution was clearly increased compared with that of the hair sample reduced with TG adjusted to pH 9.0 with monoethanolamine. In the case of adjusting to pH 9.0 with ammonia solution, the tensile strength of the waved hair treated with TG was strong compared with that of the waved hair treated with thioglycolic acid (TGA), but the waving efficiency of the waved hair treated with TG was nevertheless higher than that of the waved hair treated with TGA. The author concluded that the waved virgin human hair treated with TG adjusted to pH 9.0 with ammonia solution was less damaged as compared with the waved hair treated with TGA, despite its good waving efficiency, as not only were the GGG and GGT conformations disconnected, but they were also changed to the TGT conformation by performing the reduction process with TG.

毛髪のウォーターセットをベースとした新規ウェーブパーマ施術法

毛髪のウォーターセットをベースとした新規ウェーブパーマ施術法

Internal structural changes in keratin fibres resulting from combined hair waving and stress relaxation treatments: a Raman spectroscopic investigation.

The objective of our research was to investigate the influence of chemical treatments (reduction, stress relaxation and oxidation) on hair keratin fibres. The structure of cross-sections at various depths of virgin white human hair resulting from permanent waving treatments with stress relaxation process was directly analysed at a molecular level using Raman spectroscopy. In particular, the three disulphide (-SS-) conformations in human hair were compared by S-S band analysis. The gauche-gauche-gauche (GGG) and gauche-gauche-trans (GGT) contents of -SS- groups remarkably decreased, while the trans-gauche-trans (TGT) content was not changed by performing the reduction process with thioglycolic acid. In addition, the high-temperature stress relaxation process after reduction accelerated the disconnection of -SS- (GGG and GGT) groups in the human hair, while the low-temperature stress relaxation process after reduction accelerated the reconnection of -SS- (GGG and GGT) groups. Moreover, the S-O band intensity at 1042 cm(-1) , assigned to cysteic acid, existing in the cuticle region and the surface of the cortex region increased, while the GGG content significantly decreased by performing the oxidation process after the reduction and the high-temperature stress relaxation processes. The author concluded that the high-temperature relaxation process after reduction accelerated the disconnection of -SS- (GGG and GGT) groups, thereby leading to the remarkable local molecular disorganization (an increase in the cysteic acid content and a decrease in the GGG content) on the cuticle and cortex cells during the oxidation process.

Effect of shampoo, conditioner and permanent waving on the molecular structure of human hair.

The hair is a filamentous biomaterial consisting of the cuticle, the cortex and the medulla, all held together by the cell membrane complex. The cortex mostly consists of helical keratin proteins that spiral together to form coiled-coil dimers, intermediate filaments, micro-fibrils and macro-fibrils. We used X-ray diffraction to study hair structure on the molecular level, at length scales between ∼3–90 Å, in hopes of developing a diagnostic method for diseases affecting hair structure allowing for fast and noninvasive screening. However, such an approach can only be successful if common hair treatments do not affect molecular hair structure. We found that a single use of shampoo and conditioner has no effect on packing of keratin molecules, structure of the intermediate filaments or internal lipid composition of the membrane complex. Permanent waving treatments are known to break and reform disulfide linkages in the hair. Single application of a perming product was found to deeply penetrate the hair and reduce the number of keratin coiled-coils and change the structure of the intermediate filaments. Signals related to the coiled-coil structure of the α-keratin molecules at 5 and 9.5 Å were found to be decreased while a signal associated with the organization of the intermediate filaments at 47 Å was significantly elevated in permed hair. Both these observations are related to breaking of the bonds between two coiled-coil keratin dimers.

Hair care and dyeing.

Alopecia can be effectively camouflaged or worsened through the use of hair care techniques and dyeing. Proper hair care, involving hair styling and the use of mild shampoos and body-building conditioners, can amplify thinning scalp hair; however, chemical processing, including hair dyeing, permanent waving, and hair straightening, can encourage further hair loss through breakage. Many patients suffering from alopecia attempt to improve their hair through extensive manipulation, which only increases problems. Frequent haircuts to minimize split ends, accompanied by gentle handling of the fragile fibers, is best. This chapter offers the dermatologist insight into hair care recommendations for the alopecia patient.

Current Trends in Korea Academic Research on the Permanent Waving of Hair

Current Trends in Korea Academic Research on the Permanent Waving of Hair

Asthma and respiratory symptoms among hairdressers in Denmark: results from a register based questionnaire study.

Hairdressers are at risk of developing occupational respiratory disorders due to persulfates and other hairdressing chemicals. A register based questionnaire study comprising 7,840 graduates from hairdressing vocational schools was conducted. The postal questionnaire concerned self-reported asthma, airway symptoms, occupation, smoking, and atopic dermatitis. A response rate of 67.9% was obtained. The hairdressers reported asthma (11.2%), cough (25.3%), nasal congestion (24.0%), and rhinitis (18.2%). Less than 1/3 of all hairdressers with suspected occupational asthma reported their asthma as an occupational disease to the authorities. In total, 27.3% were daily smokers; the smoking pattern was similar between hairdressers with and without asthma. Local exhaust ventilation was only used consistently by 63.8% for permanent waving and hair coloring procedures. Asthma and especially respiratory symptoms were commonly reported by hairdressers, but rarely reported as an occupational disease. Local exhaust ventilation was inconsistently used. Our results underline the need for improved measures to ascertain and prevent occupational asthma in hairdressers.

Internal structure changes in bleached black human hair resulting from chemical treatments: A Raman spectroscopic investigation

In order to investigate in detail the influence of chemical treatments (reduction, hydrolyzed eggwhite protein (HEWP) treatment, and oxidation) on damaged hair keratin fibers, the structure of cross-sections at various depths of excessively bleached (damaged) black human hair resulting from a permanent waving process was directly analyzed using Raman spectroscopy. It was found that l-cysteine (CYS) largely reacted with the gauche-gauche-gauche (GGG) conformation of disulfide (–SS–) groups (while CYS did not react with the trans-gauche-trans (TGT) conformation). In particular, not only the GGG content, but also the cysteic acid content existing throughout the cortex region of the excessively bleached human hair remarkably decreased by performing the oxidation process after reduction. On the other hand, the GGG content of the excessively bleached black human hair increased, while the TGT content decreased by performing the oxidation process after reduction and then HEWP treatment processes.From these experiments, the authors concluded that some of the keratin associated protein (KAP), which has a rich –SS– content and cysteic acid content was eluted from the cortex region along with the disconnection of –SS– groups, thereby leading to the remarkable reduction in the reconnection of –SS– groups of the excessively bleached black human hair after the permanent waving process (the reduction and oxidation processes). Also, the authors concluded that the HEWP treatment process in the permanent waving process caused the reconstruction of the KAP, thereby contributing to the acceleration of the reconnection of –SS– groups during the oxidation process.

Exposure of hairdressers to ortho- and meta-toluidine in hair dyes

BackgroundCarcinogenic aromatic amines derived from hair dyes have recently received new attention. One of these is ortho (o)-toluidine, which is classified as carcinogenic to humans.ObjectivesTo clarify exposure of hairdressers to...

Adverse Effects of Permanent Waving and Hair Relaxation—Assessment by Scanning Electron Microscopy (SEM)

Permanent waving is very popular in Japan. Polypeptide chains (main chains) form the principal components of hair, and they are lined up longitudinally. Hair relaxation is also called straight permanent waving, and there are methods that change curly or wavy hair into straight hair. Hair damage as a result of winding, combing, and using high-temperature hairdressing irons is also often seen. By using scanning electron micrographs (SEM) we showed broken hairs and hair damage caused by permanent wave solutions. The hair damage is obvious when comparisons are made with the condition of the hair surface, condition of the cuticle, etc. Hair swelling by permanent wave solutions, manipulations such as winding, etc., inadequate rinsing with water, procedures on injured hair at the outset, etc., are considered possible reasons for any of these types of injury.

<b>Direct Observation of Hair Components Involved in Formation of Permanent Waves</b>

Hair components were extracted in order to macroscopically observe the component most involved in formation of permanent waving by thioglycolic acid. In addition, we investigated the influence of treatment with hydrolyzed keratin on permanent wave formation in hair damaged by repeated bleaching treatment. We found that microfibrils is a mandatory component for the desired shape formation of permanent wave by thioglycolic acid, and plays a major role in the shape formation in primary bond than the cuticle and matrix do. Impregnating damaged hair with hydrolyzed keratin resulted in improvement of both permanent waving efficiency and the damage of hair. We hypothesize that hydrolyzed keratin increasing the efficiency of permanent wave formation by maintaining both the shape formation ability of primary bond and the resistance to gravity at the time of secondary bond.

Effects of Water Soluble Wool Keratin on Bleaching and Permanent Waving Treatments of Hair

Effects of Water Soluble Wool Keratin on Bleaching and Permanent Waving Treatments of Hair

Effects of Some Treatment Conditions on the Wave Performance of Human Hair by Permanent Waving Procedure Incorporated Relaxation Process

Effects of Some Treatment Conditions on the Wave Performance of Human Hair by Permanent Waving Procedure Incorporated Relaxation Process