A novel approach using ATR-FTIR spectroscopy and chemometric analysis to distinguish male and female human hair samples.

This article presents an attempt to discriminate between human male and female hair samples using a single strand of scalp hair. The methodology involves the non-destructive application of ATR-FTIR spectroscopy coupled with chemometric analysis. A total of 96 hair samples, evenly distributed between 48 male and 48 female volunteers from India, were collected. Spectral analysis revealed subtle differences between the two groups, and reliance on visual interpretation might introduce biasness. To avoid subjective biases, chemometric techniques such as principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) were employed for enhanced data visualization and separation. PCA results revealed that the first 10 principal components accounted for 93% of the total variance, with three significant PCs. The PLS-DA model demonstrated a remarkable sensitivity and specificity in sex discrimination from hair samples, establishing its efficacy as a robust classification tool. Furthermore, the proposed model exhibited 100% accuracy in predicting unknown samples, underscoring its potential applicability in real-world scenarios. These outcomes affirm the viability of our approach for non-invasive classification of human male and female hair based on single-strand scalp hair analysis.

Determination of cortisone and cortisol in human scalp hair using an improved LC-MS/MS-based method.

OBJECTIVES: Human scalp hair is an easily available but complex matrix for determination of cortisone and cortisol, and has been shown to reflect long-term glucocorticoid exposure. Hair glucocorticoid analysis has been used to detect hypo- and hypercortisolism. In this study, we describe the development and validation of a LC-MS/MS method for quantification of cortisone and cortisol in human scalp hair, and provide a novel approach for analysis and interpretation of the results. METHODS: Improved sample preparation using pulverization and solid phase extraction allowed for low sample volumes (10 mg). Baseline chromatographic separation without matrix interference was achieved by reversed phase chromatography and MRM measurement in negative ion mode. Run-to-run time was 8 min. Mixed model analyses were performed to create individual patterns of cortisone and cortisol concentrations. RESULTS: Matrix matched calibration curves showed excellent linearity up to 100 pg (analyte)/mg (hair) for both cortisone and cortisol (R2>0.995). LLOQ was 1.5 and 1.0 pg/mg for cortisone and cortisol, respectively. Matrix effect was negligible for hair color (recoveries 95-105 %). Cortisone and cortisol concentrations decreased from proximal to distal hair segments, following a predictable, but subject-specific pattern, with less individual variation for cortisone than for cortisol. CONCLUSIONS: This improved LC-MS/MS method is able to accurately quantify cortisone and cortisol in human hair with minimum matrix interference. This new way of data analysis and interpretation including individual patterns of cortisone and cortisol will be of help with detection of pathological concentrations in both the high - and the low ranges of glucocorticoids.

Evaluation of hair surface structure and morphology of patients with lichen planopilaris (LPP) by atomic force microscopy (AFM).

BACKGROUND: Lichen planopilaris (LPP) is a chronic lymphocytic skin disease manifested by progressive scarring alopecia. The diagnosis of LPP is made based on histopathological examination, although it is not always definite. The current study evaluates the effectiveness of non-invasive atomic force microscopy (AFM) hair examination in detecting morphological differences between healthy and diseased hair. MATERIALS AND METHODS: Here, three to five hairs from lesional skin of 10 LPP patients were collected and examined at nine locations using AFM. At least four images were taken at each of the nine sites. Metric measurements were taken and metric (length, width, and scale step height) and morphological features (striated and smooth surface of scales, the presence of endocuticle and cortex, shape of scales edges, scratches, pitting, cracks, globules, and wavy edge) were compared with hair from healthy controls. In addition, areas on diseased hair where the process of pathological, unnatural delamination of the hair fiber occurs are described. RESULTS: There was a statistically significant difference in the number of scratches in the initial sections of the LPP hair, in the intensity of wavy edges along the entire length of the tested hair, and in the number of scales with pitting in the middle section of the hair. In addition, a statistically significant higher number of scales with striated surface was found in LPP group starting at 3.5 cm from the root continuing towards the free end of the hair. Other morphological changes such as presence of cortex, globules, oval indentations, and rod-like macrofibrillar elements were also assessed, however, detailed results are not presented, as the differences shown in the number of these morphological changes were not significantly different. CONCLUSION: This publication outlines the differences between virgin, healthy Caucasian hair, and the hair of LPP patients. The results of this study can be used for further research and work related to LPP. This is the first attempt to characterize the hair of LPP patients using AFM.

Evaluation of Surface Structure and Morphological Phenomena of Caucasian Virgin Hair with Atomic Force Microscopy.

Background and Objectives: Atomic force microscopy (AFM) as a type of scanning microscopy (SPM), which has a resolution of fractions of a nanometer on the atomic scale, is widely used in materials science. To date, research using AFM in medicine has focused on neurodegenerative diseases, osteoporosis, cancer tumors, cell receptors, proteins and the DNA mismatch repair (MMR) system. Only a few small studies of hair imaging have been conducted, mostly in biotechnology or cosmetology. Thanks to the possibilities offered by AFM imaging, dermatologists can non-invasively assess the condition of hair and its possible disorders. Our goal was to capture images and microscopically analyze morphological changes in the surface of healthy hair. Materials and Methods: In this study, three to five hairs were collected from each person. Each hair was examined at nine locations (0.5; 1.0; 1.5; 2.0; 3.5; 4.5; 5.5; 6.5 and 7.0 cm from the root). At least 4 images (4-10 images) were taken at each of the 9 locations. A total of 496 photos were taken and analyzed. Metric measurements of hair scales, such as apparent length, width and scale step height, were taken. Results: This publication presents the changes occurring in hair during the natural delamination process. In addition, morphoological changes visualized on the surface of healthy hair (pitting, oval indentations, rod-shaped macro-fibrillar elements, globules, scratches, wavy edge) are presented. A quantitative analysis of the structures found was carried out. Conclusions: The findings of this study can be used in further research and work related to the subject of human hair. They can serve as a reference for research on scalp and hair diseases, as well as hair care.

Protein Biomarkers for the Identification of Forensically Relevant Human Hair from Different Body Parts in Intimate Contact Cases.

Correctly identifying the human hair anatomic location found at crime scenes can link biological sample donors with the actual crime event, thus providing significant insight into the crime scene reconstruction. Forensic proteomic studies on human hairs can facilitate the development of new biomarkers for hair identification while compensating for the limitations of the conventional morphologic hair comparison and DNA analysis. Herein, the LC-MS/MS platform was used to find differentially expressed protein biomarkers in hairs from different body sites. The findings indicated that a total of 296 protein biomarkers with statistically significant differences in body sites were initially identified, and hair samples from the scalp, pubic, and armpit parts were distinguished from each other, which were validated by multiple bioinformatic methods. Fewer differences in protein patterns between armpit and pubic hairs while larger differences between hair and armpit as well as pubic hairs provided reasonable evidence of sexual or close intimate contact in crimes. This study lays the foundation for the development of a more reliable strategy to distinguish human hairs of various body areas from Chinese and will also support microscopic hair comparison analysis and assist in the proper handling of legal proceedings in relative cases by judicial officers, deserving special attention and further in-depth investigation. The MS proteomics data have been deposited to the ProteomeXchange Consortium via the iProX partner repository with the dataset identifier PXD038173.

Evaluation of elements in hair samples of children with developmental language disorder (DLD).

BACKGROUND: Recent studies have highlighted a role for trace elements and toxic metals across neurodevelopmental disorders, including developmental stuttering, Autistic Spectrum Disorders (ASD), and Attention Deficit/Hyperactivity Disorder (ADHD). However, these environmental influences have yet to be explored in relation to Developmental Language Disorder (DLD). METHODS: Elemental hair composition of seven elements; zinc (64Zn), magnesium (26Mg), iron (57Fe), potassium (39K), aluminum (27Al), lead (208Pb), and barium (138Ba) were analyzed in hair samples from 35 children affected by DLD and 35 controls with typical language development (TLD) using both inductive coupled plasma optical emission spectroscopy (ICP-OES) and inductive coupled plasma mass spectroscopy (ICP-MS). RESULTS: The concentration of 64Zn was significantly lower in the hair of DLD group compared to the TLD control group. All other elements showed similar levels between cases and controls. This pilot study demonstrates the utility of trace elements and toxic metals screening in relation to language disorders and the use of hair samples in such investigations. CONCLUSION: The finding that zinc levels differed between cases and controls could represent a clinically relevant result and should be replicated in larger sample size across time. A wider battery of related elements will help to better understand the role of trace elements and toxic metals in DLD.

Nanoindentation study of human fingernail for determining its structural elasticity.

BACKGROUND: Human nails play an important role in transmitting force to the fingertips, and their mechanical properties are important indices. The nail has a three-layered structure consisting of top dorsal, middle intermediate, and under ventral plates, and its internal structure is believed to affect its mechanical properties. However, this has not been investigated in previous studies. METHODS: The Young's moduli of the top, middle, and under plates were measured using nanoindentation, and a theoretical model was developed to estimate the structural elasticity for the bending deformation of human nails, which is an index describing the deformability of the nail without depending on its external dimensions. The structural elasticity of human nails was compared with that of human hair collected from the same person. The effect of the softening treatment on the nails was also evaluated. RESULTS: The Young's moduli of the top, middle, and under plates measured using nanoindentation were 2.9, 3.1, and 2.8 GPa, respectively. The structural elasticity of the nail was estimated to be 2.9 GPa, approximately 75% that of hair. Moreover, softening treatment with a urea cream reduced the structural elasticity of the nail to 70%. CONCLUSION: This paper proposed a method for estimating the structural elasticity of a human nail with a three-layered structure. This index is a mechanical property with "Pa" as a unit, and is useful for comparing deformability with the Young's modulus of other homogeneous materials or for investigating the effect of various treatments quantitatively.

Effect of DNA aptamer through blocking of negative regulation of Wnt/ß-catenin signaling in human hair follicle dermal papilla cells.

BACKGROUND: When Wnt binds to the N-terminal of Frizzled, a conformational change occurs in the C-terminal of Frizzled, which binds to Dishevelled1 (Dvl1), a Wnt signaling component protein. When Dvl1 binds to the C-terminal of Frizzled, the concentration of ß-catenin increases and it enters the nucleus to transmit cell proliferation signals. CXXC-type zinc finger protein 5 (CXXC5) binds to the Frizzled binding site of Dvl1 and interferes with Dvl1-Frizzled binding. Therefore, blocking CXXC5-Dvl1 binding may induce Wnt signal transduction. MATERIALS AND METHODS: We used WD-aptamer, a DNA aptamer that specifically binds to Dvl1 and interferes with CXXC5-Dvl1 interaction. We confirmed the penetration of WD-aptamer into human hair follicle dermal papilla cells (HFDPCs) and measured ß-catenin expression following treatment with WD-aptamer in HFDPCs, wherein Wnt signaling was activated by Wnt3a. In addition, MTT assay was performed to investigate the effect of WD-aptamer on cell proliferation. RESULTS: WD-aptamer penetrated the cell, affected Wnt signaling, and increased ß-catenin expression, which plays an important role in signaling. Additionally, WD-aptamer induced HFDPC proliferation. CONCLUSION: CXXC5-associated negative feedback of Wnt/ß-catenin signaling can be regulated by interfering with CXXC5-Dvl1 interaction.

Human biomonitoring of heavy metals exposure in different age- and gender-groups based on fish consumption patterns in typical coastal cities of China.

The study aimed to investigate heavy metals (HMs) concentrations in human hair based on fish consumption patterns in Qingdao, Xiamen, and Zhoushan. The (HMs) concentrations were determined using acid digestion and an inductively coupled plasma mass spectrometer (ICP-MS, NexION 300X, PerkinElmer). The associated health risks were investigated using risk assessment models described by the United States Environmental Protection Agency (USEPA). The order of fish HMs concentration in Qingdao was CdCrCu>Pb>Cr>As>Cd in all three study areas. The hair Zn concentration in 28 % of the studied population exceeded the safety standards. Overall, the hair HMs concentration was found to be high in middle-aged groups (19-45 and 45-59), and the hair HMs concentrations were high, especially in the case of females. A significant correlation was noticed between hair As (0.119; p < 0.05), Cr (0.231; p < 0.05),) and Cu (0.117; p < 0.05),) and fish consumption frequency. High Odd ratios (>2) were noticed for As, Cu and Zn in high fish-eating frequency. A significant non-carcinogenic risk was noticed in human Cr exposure (1.10E+00) in Xiamen, and the hazard index values indicated non-carcinogenic risk in Xiamen and Zhoushan. The carcinogenic risk for human As exposure (2.50E-05-7.09E-03) indicated a significant cancer risk.

Promotion of glyoxylic acid penetration into human hair by glycolic acid.

OBJECTIVE: Glyoxylic acid (GA) is widely used as a straight perming agent for hair care products, however, advanced GA penetration-enhancing agents are desired due to the peculiar odour and hair colour fading caused by the continuous use of GA products. Hence, it is important to develop a penetration-enhancing agent that helps minimize the GA concentration. We have found that the combined use of GA and glycolic acid (GCA) has a strong hair straightening effect. METHODS: Straightening hair test was carried out to the evaluation of the effect of additives. Liquid chromatography-mass spectrometry (LC/MS) was performed to quantify the GA penetration amount into human hair. Attenuated total reflection (ATR) Fourier transform-infrared spectroscopy (FT-IR) and FT-IR microscope were implemented to estimate the localization of GA in the hair. RESULTS: Straightening hair tests indicated that the hair straightening effect by GA was enhanced by the presence of GCA. LC/MS results showed that the addition of GCA enhanced the amount of GA that penetrated human hair by about four times. ATR FT-IR and FT-IR microscope measurements indicated that GA was localized more in the innermost region of hair (medulla) than the cortex and cuticle. The GA accumulated in the medulla disappeared after a hair straightener treatment at 180°C due to the chemical reaction. CONCLUSIONS: The GA penetration-enhancing effect of GCA is worth investigating to reduce the GA concentration in products for more comfortable use.

OBJECTIF: L'acide glyoxylique (AG) est largement utilisé en tant qu'agent de lissage pour les produits de soins capillaires. Cependant, des agents avancés améliorant la pénétration de l'AG sont souhaités en raison de l'odeur particulière et de la décoloration des cheveux causées par l'utilisation continue de produits à base d'AG. Il est donc important de mettre au point un agent améliorant la pénétration qui contribue à minimiser la concentration d'AG. Nous avons constaté que l'utilisation combinée de l'AG et de l'acide glycolique (AGC) a un fort effet lissant sur les cheveux. MÉTHODES: Un test de lissage des cheveux a été effectué pour évaluer l'effet des additifs. Une chromatographie en phase liquide avec spectrométrie de masse (liquid chromatography-mass spectrometry, LC/MS) a été réalisée pour quantifier le volume de pénétration de l'AG dans les cheveux humains. Une spectroscopie infrarouge à transformée de Fourier (Fourier transform-infrared spectroscopy, FT-IR) à réflexion totale atténuée (RTA) et un microscope FT-IR ont été adoptés pour estimer la localisation de l'AG dans les cheveux. RÉSULTATS: Les tests de lissage des cheveux ont indiqué que l'effet de lissage des cheveux de l'AG était renforcé par la présence d'AGC. Les résultats de la LC/MS ont montré que l'ajout d'AGC augmentait d'environ quatre fois la quantité d'AG pénétrant dans les cheveux humains. Les mesures de la FT-IR à RTA et du microscope FT-IR ont indiqué que l'AG était plus localisé dans la région la plus interne du cheveu (médulla) que dans le cortex et la cuticule. L'AG accumulé dans la médulla a disparu après un traitement au lisseur à cheveux à 180 °C en raison de la réaction chimique. CONCLUSIONS: L'effet d'amélioration de la pénétration de l'AG observé avec l'AGC mérite d'être étudié afin de réduire la concentration d'AG dans les produits pour une utilisation plus confortable.

The effects of dyes and bleaches on the sorption and desorption of trace elements in human hair.

Trace element concentrations and isotope ratios of hair reflect the blood levels at the time of hair formation, but can be affected by external factors such as dyeing, bleaching, and bathing. To investigate the effect of dyeing, bleaching, and bathing on hair, hair was immersed in tap water, and changes in trace element concentrations and the Sr isotope ratio were observed over time. During soaking, alkaline earth metals (Ca, Mg, and Sr) from tap water were gradually absorbed into the hair over time. After about one day, the adsorption capacity of hair reached a maximum and the reverse reaction started to occur. In contrast, alkaline metals (Na and K) behaved in reverse. In dyed and bleached hair, Na was significantly desorbed from the hair and gradually migrated to the water over time. The adsorption and desorption of trace elements were minimal in untreated original hair, but much higher in dyed and bleached hair. Thus, dyeing and bleaching appear to damage the hair surface structure and greatly promote the exchange of trace elements. The rapid exchange of trace elements, including Sr, between hair and tap water observed in this study indicates that hair samples can be easily contaminated during bathing.

Engineered extracellular vesicle mimetics from macrophage promotes hair growth in mice and promotes human hair follicle growth.

Recent studies clearly show that cell-derived extracellular vesicles (EVs, including exosomes) can promote hair growth. However, large-scale production of EVs remains a big hurdle. Recently, extracellular vesicle mimetics (EMs) engineered by extrusion through various membranes are emerging as a complementary approach for large-scale production. In this study, to investigate their ability to induce hair growth, we generated macrophage-engineered EMs (MAC-EMs) that activated the human dermal papilla (DP) cells in vitro. MAC-EMs intradermally injected into the skin of C57BL/6 mice were retained for up to 72 h. Microscopy imaging revealed that MAC-EMs were predominately internalized into hair follicles. The MAC-EMs treatment induced hair regrowth in mice and hair shaft elongation in a human hair follicle, suggesting the potential of MAC-EMs as an alternative to EVs to overcome clinical limitation.

Compound-Specific Stable Isotope Analysis Provides New Insights for Tracking Human Monomethylmercury Exposure Sources.

Monomethylmercury (MMHg) exposure can induce adverse neurodevelopmental effects in humans and is a global environmental health concern. Human exposure to MMHg occurs predominately through the consumption of fishery foods and rice in Asia, but it is challenging to quantify these two exposure sources. Here, we innovatively utilized MMHg compound-specific stable isotope analyses (MMHg-CSIA) of the hair to quantify the human MMHg sources in coastal and inland areas, where fishery foods and rice are routinely consumed. Our data showed that the fishery foods and rice end members had distinct Δ199HgMMHg values in both coastal and inland areas. The Δ199HgMMHg values of the human hair were comparable to those of fishery foods but not those of rice. Positive shifts in the δ202HgMMHg values of the hair from diet were observed in the study areas. Additionally, significant differences in δ202Hg versus Δ199Hg were detected between MMHg and inorganic Hg (IHg) in the human hair but not in fishery foods and rice. A binary mixing model was developed to estimate the human MMHg exposures from fishery foods and rice using Δ199HgMMHg data. The model results suggested that human MMHg exposures were dominated (>80%) by fishery food consumption and were less affected by rice consumption in both the coastal and inland areas. This study demonstrated that the MMHg-CSIA method can provide unique information for tracking human MMHg exposure sources by excluding the deviations from dietary surveys, individual MMHg absorption/demethylation efficiencies, and the confounding effects of IHg.

Levels, Spatial Distribution, and Impact Factors of Heavy Metals in the Hair of Metropolitan Residents in China and Human Health Implications.

Chronic exposure to low levels of heavy metals threatens human health. However, few studies evaluated the health effects and spatial distributions of chronic exposure to heavy metals in metropolitan residents throughout mainland China using unified sampling methods and evaluation indicators at the national level. Here, the concentrations and spatial distributions of heavy metals (As, Cd, Cr, Sb, Pb, and Hg) in the hair of 1202 metropolitan residents from mainland China were analyzed, and differences in age and sex were evaluated. Most target metals exhibited higher concentrations in the hair of residents from South Central China. Generally, male hair had higher As and Se concentrations, whereas female hair had higher Cd and Pb levels (p < 0.05). A significant pairwise correlation existed between most metals in hair, especially Cd-Pb (r = 0.638, p < 0.05). The Se/heavy metal molar ratio is used as an indicator to assess the detoxification ability. The results demonstrated that protecting metropolitan residents in South Central China from heavy metals in their daily life is crucial, particularly for Hg, Pb, and Cr with Se/(Hg, Pb, or Cr) molar ratios < 1. This is the first study to comprehensively consider the antagonistic effects of Se and heavy metals using the molar ratio of Se/heavy metals to evaluate health implications and propose health management policies for metropolitan residents in China.

Nanoscale microenvironment engineering for expanding human hair follicle stem cell and revealing their plasticity.

BACKGROUND: Periodically regenerated hair follicles provide an excellent research model for studying tissue regeneration and stem cell homeostasis. Periodic activation and differentiation of hair follicle stem cells (HFSCs) fuel cyclical bouts of hair regeneration. HFSCs represent an excellent paradigm for studying tissue regeneration and somatic stem cell homeostasis. However, these crucial studies are hampered by the lack of a culture system able to stably expand human HFSCs and regulate their fate. RESULTS: Here, we use layer-by-layer (LbL) self-assembly with gelatin/alginate to construct a nanoscale biomimetic extracellular matrix (ECM) for an HFSC population. The LbL coating provides ECM and mechanical support for individual cells, which helps to maintain the CD200+α6+ HFSC population to a certain extent. Addition of key signal molecules (FGF-7 and VEGF-A) simulates the minimum essential components of the stem cell microenvironment, thereby effectively and stably expanding HFSCs and maintaining the CD200+α6+ HFSC population. Subsequently, BMP2 loaded to the nanocoated layer, as a slow-release signal molecule, activates BMP signaling to regulate HFSCs' fate in order to obtain a purified CD200+α6+ HFSC population. CONCLUSION: This system can minimize the microenvironment of HFSCs; thus, stably amplifying HFSCs and revealing their plasticity. Our study thus provides a new tool for studies of hair follicle reconstruction and stem cell homeostasis.

Exposure of the residents around the Three Gorges Reservoir, China to chromium, lead and arsenic and their health risk via food consumption.

Hydrological management of the Three Gorges Dam has resulted in the interception of heavy metals in the Three Gorges Reservoir (TGR). However, the exposure to heavy metals and health risks among local residents remained poorly understood. Here we collected 208 biomarker samples (hair) and 20 food species from typical regions in the TGR to assess the exposure levels of three toxic metals (Cr, Pb and As) in residents of the TGR, and subsequently investigated their health risk via dietary intake. Results indicated that hair Cr and As levels were below the reference value for normal people and threshold of skin lesions, respectively, whereas about 22% hair Pb exceeded the reference for clinical medicine, indicating a potential Pb exposure of local residents. Smoking habit and fish consumption were found to be predictors for hair Pb. In addition, the concentrations of heavy metals in all investigated food samples were below the limits of contaminants in food in China, except for Pb in the sweet potato and fish. The estimated daily intake of metals (DIMs) revealed that the intakes of Cr and As from studied food were under the recommended thresholds of Cr and As. However, the intake of Pb via diet exceeded the limit of the prevalence of chronic kidney disease and closed to the threshold for cardiovascular, which was probably associated with the high Pb concentrations of fish and sweet potato. Overall, residents around the TGR were at low exposure to Cr and As, but Pb exposure may need more attention.

Micro-Current Stimulation Has Potential Effects of Hair Growth-Promotion on Human Hair Follicle-Derived Papilla Cells and Animal Model.

Recently, a variety of safe and effective non-pharmacological methods have been introduced as new treatments of alopecia. Micro-current electrical stimulation (MCS) is one of them. It is generally known to facilitate cell proliferation and differentiation and promote cell migration and ATP synthesis. This study aimed to investigate the hair growth-promoting effect of MCS on human hair follicle-derived papilla cells (HFDPC) and a telogenic mice model. We examined changes in cell proliferation, migration, and cell cycle progression with MCS-applied HFDPC. The changes of expression of the cell cycle regulatory proteins, molecules related to the PI3K/AKT/mTOR/Fox01 pathway and Wnt/ß-catenin pathway were also examined by immunoblotting. Subsequently, we evaluated the various growth factors in developing hair follicles by RT-PCR in MCS-applied (MCS) mice model. From the results, the MCS-applied groups with specific levels showed effects on HFDPC proliferation and migration and promoted cell cycle progression and the expression of cell cycle-related proteins. Moreover, these levels significantly activated the Wnt/ß-catenin pathway and PI3K/AKT/mTOR/Fox01 pathway. Various growth factors in developing hair follicles, including Wnts, FGFs, IGF-1, and VEGF-B except for VEGF-A, significantly increased in MCS-applied mice. Our results may confirm that MCS has hair growth-promoting effect on HFDPC as well as telogenic mice model, suggesting a potential treatment strategy for alopecia.

Keratin-Alginate Sponges Support Healing of Partial-Thickness Burns.

Deep partial-thickness burns damage most of the dermis and can cause severe pain, scarring, and mortality if left untreated. This study serves to evaluate the effectiveness of crosslinked keratin-alginate composite sponges as dermal substitutes for deep partial-thickness burns. Crosslinked keratin-alginate sponges were tested for the ability to support human dermal fibroblasts in vitro and to support the closure and healing of partial-thickness burn wounds in Sus scrofa pigs. Keratin-alginate composite sponges supported the enhanced proliferation of human dermal fibroblasts compared to alginate-only sponges and exhibited decreased contraction in vitro when compared to keratin only sponges. As dermal substitutes in vivo, the sponges supported the expression of keratin 14, alpha-smooth muscle actin, and collagen IV within wound sites, comparable to collagen sponges. Keratin-alginate composite sponges supported the regeneration of basement membranes in the wounds more than in collagen-treated wounds and non-grafted controls, suggesting the subsequent development of pathological scar tissues may be minimized. Results from this study indicate that crosslinked keratin-alginate sponges are suitable alternative dermal substitutes for clinical applications in wound healing and skin regeneration.

Injectable Human Hair Keratin-Fibrinogen Hydrogels for Engineering 3D Microenvironments to Accelerate Oral Tissue Regeneration.

Traumatic injury of the oral cavity is atypical and often accompanied by uncontrolled bleeding and inflammation. Injectable hydrogels have been considered to be promising candidates for the treatment of oral injuries because of their simple formulation, minimally invasive application technique, and site-specific delivery. Fibrinogen-based hydrogels have been widely explored as effective materials for wound healing in tissue engineering due to their uniqueness. Recently, an injectable foam has taken the spotlight. However, the fibrin component of this biomaterial is relatively stiff. To address these challenges, we created keratin-conjugated fibrinogen (KRT-FIB). This study aimed to develop a novel keratin biomaterial and assess cell-biomaterial interactions. Consequently, a novel injectable KRT-FIB hydrogel was optimized through rheological measurements, and its injection performance, swelling behavior, and surface morphology were investigated. We observed an excellent cell viability, proliferation, and migration/cell-cell interaction, indicating that the novel KRT-FIB-injectable hydrogel is a promising platform for oral tissue regeneration with a high clinical applicability.

Investigation of the interactions of cationic guar with human hair by electrokinetic analysis.

OBJECTIVE: Cationic guar is an important polysaccharide used as a hair conditioning agent in personal care products. In this article, we report streaming potential data demonstrating its behaviour as it interacts electrostatically with hair. Several cationic guar variants with different molecular weights (MWs) and charge densities (CDs) were examined. METHODS: All experiments were carried out with a custom-designed streaming potential instrument so that in situ, real-time data were monitored during the treatment of a hair plug with aqueous solutions of cationic guar and subsequent treatment with anionic surfactants-sodium laureth sulfate (SLES) and cocamidopropyl betaine (CAPB)-commonly found in contemporary shampoo formulations. RESULTS: The MW of the cationic guar variants plays an integral role in determining the thickness of the adsorbed polymer layer on the hair surface while CD influences the zeta potential. Data were also generated for the treatment of hair with a cationic flexible polymer (polyquaternium-28) and cationic conditioning surfactant (behentrimonium chloride) to provide a frame of reference. The deposition behaviour on hair of high MW cationic guar variants is distinct from these conventional molecules in terms of its electrokinetic properties. We also examined the electrokinetic behaviour of cationic guar on hair types from different racial backgrounds. While the cationic guar treatment yielded similar results for the different hair types, anionic surfactant treatment resulted in quicker sorption and desorption from African, European 65% grey, and Mulatto hair as compared to Chinese, European dark brown, and Indian hair. CONCLUSION: We introduce an in situ technique for measuring the dynamic sorption/desorption of charged molecules on the surface of human hair. Evaluation of a series of cationic guar species revealed varying behaviour depending on the MW and CD of the polysaccharide. Our data also demonstrate differences in the desorption properties of typical shampoo surfactants for hair from diverse racial backgrounds.

OBJECTIF: Le guar cationique est un polysaccharide important utilisé comme conditionneur capillaire dans les produits cosmétiques. Dans ce rapport, nous démontrons l'utilisation de la technique du potentiel de streaming pour étudier comment le guar cationique interagit électrostatiquement avec les cheveux. Plusieurs variantes del guar cationique avec différents poids moléculaires et densités de charge ont été examinés. MÉTHODES: Nous avons utilisé un instrument de potentiel de streaming pour les expériences. Les études ont été réalisées en temps réel pour surveiller le traitement de cheveu avec des solutions aqueuses de guar cationique suivi d'un traitement ultérieur avec tensioactifs anioniques comment le sulfate de laureth de sodium et le cocamidopropyle bétaïne, des ingrédients généralement trouvés dans les formulations de shampooing. RÉSULTATS: Le poids moléculaire des variants du guar cationique joue un rôle intégral dans la détermination l'épaisseur de la couche de polymère adsorbée sur la surface des cheveux tandis que le densité de charge influence le potentiel zêta. Des données ont également été générées pour le traitement des cheveux avec un polymère flexible (polyquaternium-28) et tensioactif de conditionnement cationique (behentrimonium chlorure) pour fournir un cadre de référence. Le comportement de dépôt sur les cheveux des variants de guar cationiques à poids moléculaire élevé est distinct de ces molécules conventionnelles en termes de ses propriétés électrocinétiques. Nous avons également examiné le comportement électrocinétique de guar cationique sur des types de cheveux de différents milieux raciaux. Le traitement avec le guar cationique a donné des résultats similaires pour les différents types de cheveux. En contraste avec ceci, le traitement avec le tensioactif anionique a entraîné une sorption et une désorption plus rapides de cheveux africains, de cheveux européens (65% gris) et de cheveux mulâtres en comparaison à les cheveux chinois, européens et indiens. CONCLUSION: Nous introduisons une technique in situ pour mesurer la sorption et la désorption dynamique de molécules chargées à la surface des cheveux humains. L'évaluation d'une série des espèces de guar cationiques ont révélé un comportement variable en fonction du poids moléculaires et densités de charge de le polysaccharide. Nos données démontrent également des différences dans les propriétés de désorption de tensioactifs de shampooing typiques pour les cheveux de diverses origines raciales.