No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Mapping penetration of cosmetic compounds into hair fibers using time-of-flight secondary ion mass spectrometry (TOF-SIMS)
Abstract
In this communication, penetration of vegetable oils into hair fibers has been investigated by the TOF-SIMS (Time-Of-Flight Secondary Ion Mass Spectrometry) method. In earlier work [1], the method was found suitable to study the penetration of coconut and mineral oils into human hair. Therefore, the study has been extended to a group of vegetable oils with different types of unsaturation in the fatty acid components. Different patterns of penetration have been observed for oils of different molecular structure. The general pattern which emerges from this study is that polyunsaturated oils do not penetrate at all, or do so only sparingly into the structure of hair. Most of these molecules seem to penetrate only into the cuticular region of the hair fiber. Oils with polyunsaturated fatty acids seem to have difficulty in penetrating hair. It is possible that these molecules do not fit into the fiber's cell membrane complexes, which are known to be the diffusion pathways in the keratin fiber. On the other hand, monounsaturated oils, such as olive oil, with more compact molecular structure seem to penetrate readily into the hair fiber.
... Cosmetic industries seek techniques capable of elucidating the mechanism of action of various molecules to study their effects and demonstrate their efficacy on substrates like skin and hair. Although secondary ion mass spectrometry (SIMS) has been more utilized in hair studies among mass spectrometry techniques [8,32,33] due to its resolution, MALDI-TOF allows for the investigation of a wider mass range of materials (1-500 kDa) compared to SIMS [31]. ...
... In textured hair, the orthocortex and paracortex cells are arranged bilaterally, with the orthocortex concentrated in the external portion of the curl, and the paracortex in the internal portion [25,26]. Hornby et al. [33] reported that the diffusion coefficient of the orthocortex area is approximately one order of magnitude greater than that of the paracortex. Considering these configurations, molecules that penetrate straight hair will primarily diffuse through the orthocortex along the entire perimeter of the fibers, after passing through the cuticular barrier, and may spread throughout the entire orthocortical ring. ...
The promotion of natural beauty has empowered women with textured hair to embrace their natural hair texture and opt for bleaching as a means of style variation. However, bleaching exacerbates the inherent fragility of this hair type, necessitating treatments to partially restore its mechanical properties. Vegetable oils, renowned for their strengthening properties, were evaluated regarding (I) their ability to penetrate both virgin and bleached textured hair using Matrix-Assisted Laser Desorption Ionization (MALDI) time-of-flight (TOF) analysis, and (II) their effects by way of tensile and fatigue tests. The MALDI–TOF results revealed groups of oil molecules in the cortical region of the bleached textured hair. The tensile test results, in turn, showed that the oil treatments were unable to alter the mechanical properties of the hair. Conversely, the fatigue test showed an increase in resistance in the virgin hair, most likely attributed to a lubrication effect in the outermost portions of the cortex and cuticles. In the bleached hair, a reduction in resistance was noted following the treatment with the oils. Comparative analysis with a previous study on straight hair by our group suggests that external molecules diffuse more homogeneously in straight hair than in textured hair. The unique cortical structure of textured hair creates two areas with distinct diffusion zones, resulting in the irregular distribution of external materials and different effects compared to straight hair.
... While a number of research discussed about the effect of penetration of vegetable oils into hair (Keis et al., 2005;Lee & Ahn, 2022;Rele & Mohile, 2003) there has been only a few research efforts which provided the empirical data (Gamez-Garcia, 2009;Gode et al., 2012;Hornby et al., 2005;Ruetsch et al., 2001). Ruetsch et. ...
... ich provided the empirical data (Gamez-Garcia, 2009;Gode et al., 2012;Hornby et al., 2005;Ruetsch et al., 2001). Ruetsch et. al. (2001) used the time-of-flight secondary ion mass spectrometry to find that coconut oil penetrated into the center of hair while mineral oil showed no evidence of penetration (Ruetsch et al., 2001). Using the same method Hornby et. al. (2005) found that polyunsaturated oils did not penetrate the hair while mono-unsaturated oils penetrated readily. Using the radiolabeling method, Gode et. al. (2012) found that tritiated coconut oil penetrated the hair by 14.5-26.3% by weight of hair (Gode et al., 2012). While previous literatures provided valuable information on the penetrati ...
Hair treatments containing vegetable oils protect the damaged hair by surface coating and by penetrating in hair thereby filling the gaps caused by oxidative damage. Vegetable oil is composed mostly of medium-chain or long-chain fatty acids which exist as triglycerides. Although there are literatures which deal with the penetration of specific natural oils into hair there is a lack of research which provide the empirical data that can be used to explain the penetration of larger population of vegetable oils. This research was aimed to examine whether the chain length of fatty acid affect the penetration of fatty acid and protection in hair and also to apply the results on explaining the protective effect of Medium-Chain Triglyceride oil (MCT oil) and Coconut oil. Nine different hair treatments were formulated with three medium-chain fatty acids (C8:0, C10:0, C12:0), three long-chain fatty acids (C14:0, C16:0, C18:0), MCT oil, Coconut oil, and a blank. Composition of fatty acids of hair was examined by the Gas chromatography mass spectrometry. Penetration of fatty acid in hair was examined by the UV–VIS spectrophotometry. Protection of damaged hair was examined by the differences in color, tensile strength, thickness, and the concentration of protein leak of 21-day vs. 0-day measurements. Results of t-test indicated that the penetration and the protection of the medium-chain fatty acid was significantly better than those of the long-chain fatty acid, and that MCT oil and coconut oil were not significantly different.
... CNO is a saturated triglyceride, whereas SBO is a polyunsaturated triglyceride. There is evidence that the latter does not penetrate hair as well as the former (Hornby et al., 2005). Thus CNO could diffuse deeper penetrates into the matrix than SBO, and block the hydrophilic sites for the penetration of D 2 O (or water). ...
... Thus CNO could diffuse deeper penetrates into the matrix than SBO, and block the hydrophilic sites for the penetration of D 2 O (or water). This is in agreement with the earlier work on the penetration of saturated and polyunsaturated oil (Hornby et al., 2005). This difference in the intensity between the CNO-and SBO-treated is no longer present in the heat-treated (HT) hairs. ...
Intermediate filaments (IFs) are ubiquitous in biological structures including hair. Small-angle neutron scattering (SANS) data from hydrated samples were used in this study to investigate the distribution of water in hair, and model the structure of the IF assembly. A main diffraction peak at a d-spacing of ∼90 Å and two weaker reflections show that IFs are arranged in a ∼105 Å quasi-hexagonal lattice. Changes in the diffraction peaks show that only a small fraction of the water absorbed by hair enters between the IFs, and little water diffuses into the core of the IFs. The amount of water in the IF assembly increases rapidly up to 10% relative humidity (RH), and then slowly with further increase in RH. Most of the water appears to reside outside the IF assembly, in the voids and at the interfaces, and contribute to the central diffuse scattering. The IF assembly in the decuticled hair absorbs more water and is more ordered than that the native hair. This suggests that cuticle acts as a barrier, and might constrain the structure by compressing the cortex radially. Treatments with oils that are hydrophobic, heat treatment, and reduction of the S-S linkages that opens up the matrix by disulfide bond cleavage, all affect structure and water permeability. Coconut oil was found to impede hydration more than the soybean oil because of its ability to penetrate deeper into hair. A new model for the IF assembly that is sterically more favorable than the previous models is proposed.
... Research suggests that the intercellular pathway is the most preferred route, where materials surround the cells of the cuticle and cortex via the CMC and non-crystalline regions. Hornby et al. [11] noted that low-sulfur, non-keratinous environs swell more easily than highly cross-linked regions, better accommodating the presence of diffusing molecules. In addition, Malinauskyte at al. [8] pointed out that low-molecular-weight species tend to allocate to these regions, where they establish ionic interactions with matrix proteins. ...
The mitigation of damaged hair conditions involves the application and penetration of substances to stabilize broken bond sites, restore lipids and proteins, reinstate hydrophobicity, and recover hair mechanical properties. Vegetable oils, in general, exhibit a list of advantageous characteristics much desired by consumers, given the associated benefits for hair fibers. While coconut oil is highly popular in the hair care market and extensively studied for its ability to diffuse through the hair cortex, the effects of avocado and argan oil on the internal structure of hair and their potential benefits remain underexplored. Tensile and fatigue tests, as well as Raman spectroscopy, were carried out to investigate the interaction of these three oils with virgin and bleached Caucasian hair. The oils were applied in sufficient amounts directly to hair tresses and maintained for 24 h at 25 °C. Our results show that the three oils successfully diffused and interacted with the cortical region of the hairs. Their impact on hair mechanical properties depends on the level of damage and humidity conditions. In virgin hair, coconut and avocado oil reinforce the hydrophobic barrier of the cellular membrane complex, preventing water from causing intense perturbation of the mechanical properties, leading to increased stiffness and break stress. Meanwhile, due to the high degree of unsaturation of its fatty acid chains, argan oil increases water absorption, resulting in losses in hair resistance. When bleached, the hydrophilicity of the hair fiber increases, determining more affinity for argan oil. Consequently, the affinity with water is also elevated, causing increased fragility to mechanical stress. The analyzed vegetable oils are not always beneficial for hair care. Their specific chemical characteristics and hair conditions will influence the final results and should be taken into consideration in hair care product development.
... This suggests that this diffusion-blocking effect is weaker with soybean oil than with coconut oil. This could be because of smaller amount of soybean oil penetrates into the fi ber and thus blocks fewer pathways for penetration of water than coconut oil (24). These results show that SANS is a useful technique for studying substrates that have been rendered hydrophobic by oil or other treatments, which block diffusion of water. ...
... [39] Using a similar approach, Ruetsch et al. studied coconut and mineral oils, and subsequently a set of vegetable oils with different types of unsaturation in the fatty acid components and cationic conditioning compounds. [40][41][42] The penetrating effects of polymers into the hair cortex region to assist in dye-color retention have also been shown by optical microscopy of cross-sections of hair strands. [21] In quantitative studies, Jones and Chahal [29] showed that over 50% of botanical and protein extracts in cosmetic products can be retained in the hair structure, while Zimmerley et al. [43] showed that~7% of externally applied d-glycine percolates into hair fibers. ...
Rationale:
In forensic investigation, radiocarbon ((14) C) measurements of human tissues (i.e., nails and hair) can help determine the year-of-death. However, the frequent use of cosmetics can bias hair (14) C results as well as stable isotope values. Evidence shows that hair exogenous impurities percolate beyond the cuticle layer, and therefore conventional pretreatments are ineffective in removing them.
Methods:
We conducted isotopic analysis ((14) C, δ(13) C, δ(15) N and C/N) of conventionally treated and cross-flow nanofiltered amino acid (CFNAA)-treated samples (scalp- and body-hair) from a single female subject using fingernails as a reference. The subject studied frequently applies a permanent dark-brown dye kit to her scalp-hair and uses other care products for daily cleansing. We also performed pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses of CFNAA-treated scalp-hair to identify contaminant remnants that could possibly interfere with isotopic analyses.
Results:
The conventionally treated scalp- and body-hair showed (14) C offsets of ~21‰ and ~9‰, respectively. These offsets confirm the contamination by petrochemicals in modern human hair. A single CFNAA extraction reduced those offsets by ~34%. No significant improvement was observed when sequential extractions were performed, as it appears that the procedure introduced some foreign contaminants. A chromatogram of the CFNAA scalp-hair pyrolysis products showed the presence of petroleum and plant/animal compound residues, which can bias isotopic analyses.
Conclusions:
We have demonstrated that CFNAA extractions can partially remove cosmetic contaminants embedded in human hair. We conclude that fingernails are still the best source of keratin protein for year-of-death determinations and isotopic analysis, with body-hair and/or scalp-hair coupled with CFNAA extraction a close second. Copyright © 2015 John Wiley & Sons, Ltd.
... This suggests that this diffusion-blocking effect is weaker with soybean oil than with coconut oil. This could be because of smaller amount of soybean oil penetrates into the fi ber and thus blocks fewer pathways for penetration of water than coconut oil (24). These results show that SANS is a useful technique for studying substrates that have been rendered hydrophobic by oil or other treatments, which block diffusion of water. ...
Diffusion and distribution of water in hair can reveal the internal structure of hair that determines the penetration of various products used to treat hair. The distribution of water into different morphological components in unmodified hair, cuticle-free hair, and hair saturated with oil at various levels of humidity was examined using small-angle neutron scattering (SANS) by substituting water with deuterium oxide (D2O). Infrared spectroscopy was used to follow hydrogen-deuterium exchange. Water present in hair gives basically two types of responses in SANS: (i) interference patterns, and (ii) central diffuse scattering (CDS) around the beam stop. The amount of water in the matrix between the intermediate filaments that gives rise to interference patterns remained essentially constant over the 50-98% humidity range without swelling this region of the fiber extensively. This observation suggests that a significant fraction of water in the hair, which contributes to the CDS, is likely located in a different morphological region of hair that is more like pores in a fibrous structure, which leads to significant additional swelling of the fiber. Comparison of the scattering of hair treated with oil shows that soybean oil, which diffuses less into hair, allows more water into hair than coconut oil. These preliminary results illustrate the utility of SANS for evaluating and understanding the diffusion of deuterated liquids into different morphological structures in hair.
... Although the method could show the depth of penetration, it was incapable of yielding quantitative (how much) data. Since then, the TOF-SIMS method has been used by Hornby et al. (2) to study the penetration of other vegetable oils. ...
Hair is subject to damage, and the challenge is to find oils that can permeate the hair fiber to its inner layers, providing protection. This study aimed to analyze the permeation of copaiba, andiroba, and coconut oils into human hair fibers using confocal Raman spectroscopy (CRS).
Five untreated hair fibers (control) and five treated fibers were used, with 10 μl of each oil applied to the treated fibers. Raman spectra were collected before and after 30 minutes of treatment, from the surface to a depth of 40 μm. Data preprocessing involved removing fluorescence, smoothing, and vector normalization. After data processing, biochemical characterization, identification of marker peaks, and calculation of the area under the curve were performed to detect the permeation profile of each oil.
Quantification of the permeated oil concentration showed a similarity between the permeation of copaiba oil (30.14 a.u.) and coconut oil (27.85 a.u.), both reaching the deepest layer of the fiber (medulla). Andiroba oil also permeated to the deepest layer but showed a lower concentration (14.09 a.u.). These differences in concentration (a.u.) can be attributed to the biochemical composition of the oils, especially concerning the degree of saturation.
Therefore, the CRS technique demonstrated that all three oils permeated to the innermost layer of the hair fiber, providing greater insight into their permeation capacity. This knowledge allows for their varied use in the industry, including for the recovery of damaged hair, making it healthier.
Objective:
The present study is intended to characterize the surfactant damage suffered by the hair cortex in routine washing and the mechanistic effect of Coconut Based Hair Oils (CBHO) to mitigate the damage.
Methods:
Surfactants which diffuse into the hair structure solubilize protein moieties, leading to an increase in porosity and internal surface area as well as the pore volume. The changes in hair pores occurring in the hair cortex are measured by nitrogen sorption method in line with the Brunauer-Emmett-Teller (BET) theory. Single fiber tensile parameters were measured using Diastron MTT 175. Color protection was measured quantitatively using spectrophotometer as well as visual rating by trained panelists.
Results:
The pore surface area data clearly show the benefit of introducing coconut-based hair oils (CBHO) into the hair by preventing increase in hair porosity. A statistically significant decrease in break stress and toughness were observed and the same were reversed by the application of CBHO. A pronounced color protection effect was also recorded with the application of CBHO.
Conclusion:
The porosity reduction effect seen with the use of CBHO is attributed to the CBHO molecules blocking the diffusion pathways in the endocuticle and the matrix part of the cortical cells, limiting protein surfactant interaction resulting in reduced solubilization and loss. Since, the color molecules are likely to be much smaller than the protein moieties, a pronounced color protection effect suggests that the penetrated CBHO molecules form a dense diffusion barrier in the matrix, cell membrane complex (CMC) and the endocuticle regions of hair - which are the main diffusion pathways out of hair. The study confirms the damage repair potential of CBHO and that it works by increasing the hydrophobicity of hair - both on the hair surface and in the cortex.
Both human skin and plants have evolved mechanisms to respond to the consequences of light exposure. For example, studies have shown that keratinocytes can sense light and that they have their own tight circadian rhythm.10 These mechanisms act by absorbing damaging radiation, scattering it and/or reflecting it, while also fighting the formation of free radicals that can interfere with cellular machineries.
J. Cosmet. Sci., 60, 85–95 (March/April 2009)
An analysis of the light interference patterns produced by the penetration and removal of lipids from the cuticle sheath has shown that cuticle cells in their virgin state have a few intrinsic imperfections in the form of voids and cracks. The experiments also showed that when the cuticle sheath undergoes friction, extension, torsion, and thermal stresses additional microvoids, cavities, and gaps are created at the cuticle cells subsurface. Because of the activity of the sebaceous glands it is quite normal to find these cavities filled with exogenous lipids. Cuticle sheath dehydration, lipid addition, and lipid removal indicate that the viscoelastic deformations giving rise to microcavities can be reversible or irreversible. The presence of exogenous lipids in these cavities was found to be critical in maintaining the mechanical integrity of the cuticle cells. Regions presenting microcavities and cracks produced by reversible deformations were seen to fully recover and heal with the onset of a plasticization effect produced by the synergy of lipids and water. In contrast, microcavities produced by irreversible deformations were always filled with lipids. In both cases the lipids acted as weak adhesives, in particular, in those cavities and gaps opened in the cuticle cell interfaces.
ResearchGate has not been able to resolve any references for this publication.