Search Results (218)

Lactoferrin is a naturally occurring bioactive glycoprotein that is part of the body’s innate immune system and has essential roles in iron metabolism, microbial defense, inflammation regulation, and tissue repair. It supports the natural regulation of iron bioavailability in skin and hair follicles, helping to reduce excess free-iron-driven oxidative stress while preserving levels of necessary iron for cellular functions. Lactoferrin promotes cell regeneration by increasing proliferation across in vitro systems, stimulating wound healing in scratch assays, and boosting matrix production in fibroblast models. Lactoferrin can also modulate inflammatory signaling involved in skin and hair physiology by providing balanced cytokine suppression, suggesting potential value in cosmetic or dermatological applications. Here, we present the first focused summary of lactoferrin’s role specifically in skin and hair biology, distinguished from prior reviews in systemic or multi-system broad health contexts. We link mechanistic insights with clinical and preclinical evidence and uniquely map molecular functions to dermatologic and trichologic outcomes. We also provide an overview of clinical skin studies that have explored lactoferrin as a supportive agent in conditions such as acne, and highlight that, despite mechanistic plausibility, there are no existing available reports of well-controlled human clinical trials leveraging lactoferrin for hair-focused outcomes. In summary, we propose lactoferrin as not just an anti-inflammatory molecule, but also as a microenvironment stabilizer, and particularly relevant for hair and skin support as an alternative to pharmacological interventions. By addressing both established and underexplored applications, this review provides a translational framework for clinical development and provides a comprehensive rationale behind leveraging lactoferrin for hair and skin epithelial health. Full article

Canities results from a progressive decline in melanocyte activity and melanin synthesis and is commonly associated with aesthetic concerns that motivate the use of cosmetic products for hair color correction. Shampoo, due to its frequent use, represents a suitable vehicle for the gradual deposition of pigments on the hair fiber. This study aimed to design and develop a shampoo containing dark synthetic semi-permanent dyes for the gradual coverage of gray hair. Four shampoo formulations were developed and evaluated through in vitro tests using bleached hair tresses to assess color deposition and performance. The selected formulation was subsequently subjected to accelerated stability studies and color sustainability evaluation. The results showed that the formulation maintained organoleptic, physicochemical, microbiological, and functional stability. Color sustainability assays indicated that the gray–black coloration persisted on hair tresses containing approximately 90% canities after eight washing cycles. The formulation incorporating the semi-permanent dyes Basic Blue 124, Basic Yellow 87, Basic Orange 31, and Basic Red 51 achieved a gradual gray–black tonal effect. In conclusion, the developed shampoo demonstrated stability and effectiveness for the gradual cosmetic coverage of gray hair. Full article

Dermal papilla (DP) cells orchestrate hair follicle growth and cycling by secreting signaling molecules that stimulate follicular epithelial stem cells. The signal peptide CUB-EGF-like domain-containing protein 3 (SCUBE3) was recently identified as a potent anagen stimulator secreted by DP cells. Ageratum houstonianum ethanolic extract (AHE) and its active constituent agerarin exhibit anti-inflammatory properties; however, their effects on hair follicle growth remain unclear. This study aimed to investigate the effects of AHE and agerarin on SCUBE3 expression in primary human DP cells and to elucidate the underlying molecular signaling pathway. Cell viability was assessed by measuring cell confluency. Ex vivo hair growth was analyzed using organ cultures of human hair follicles. Gene and protein expression were determined using reverse transcription-PCR, immunoblot analysis, immunofluorescent staining, tyramide signal amplification-based multiplex immunohistochemistry, and gene promoter-reporter assay in primary human follicle DP cells. In a hair follicle organ culture model, both AHE and agerarin increased the population of the anagen phase and promoted hair shaft elongation. AHE and agerarin significantly upregulated SCUBE3 expression at both the mRNA and protein levels. Mechanistically, AHE and agerarin induced activator protein-1 (AP-1) expression by activating mitogen-activated protein kinase signaling pathways, thereby increasing SCUBE3 gene promoter activity. AHE and agerarin promoted hair follicle growth by upregulating SCUBE3 expression via activation of the MAPK–AP-1 signaling axis. In conclusion, AHE and agerarin may serve as potential therapeutic agents for the prevention and treatment of alopecia (hair loss). Full article

Background/Objectives: Cortisol has become established as a relevant biomarker due to its association with various pathologies, including its potential utility in mental health research. However, regarding the techniques employed for its analysis, the available literature shows a certain degree of heterogeneity both in the methods used to obtain cortisol and in the analytical techniques employed for its measurement. This makes it difficult to compare results across specific populations, particularly in pregnant women, who experience metabolic and physiological changes characteristic of gestation. Therefore, the aim of this study was to describe the procedure for the extraction and analysis of cortisol in hair samples from pregnant women throughout gestation. Methods: Hair samples, three centimeters in length, were obtained from women during the first, second, and third trimesters of pregnancy. These samples underwent a standardized isopropanol washing step, followed by milling in a laboratory mill using zirconium balls of varying diameters. The resulting hair powder was then weighed and subjected to four incubation cycles using HPLC-grade methanol. Cortisol levels were detected using chemiluminescence immunoassay. Results: Mean hair cortisol levels were 4.1 μg/L (ng/mL) in the first trimester, 11.5 μg/L (ng/mL) in the second trimester, and 6.6 μg/L (ng/mL) in the third trimester. Conclusions: Standardizing the methodology for cortisol extraction improves the reproducibility of results and, in the long term, may support its incorporation into clinical practice as a useful tool for assessing cortisol levels in both pregnant women and the general population, since hair cortisol enables retrospective evaluation of its cumulative exposure over time, approximately on a monthly basis. Full article

Heavy metals including mercury (Hg), lead (Pb), cadmium (Cd), and arsenic (As) remain significant global toxins due to their environmental persistence, widespread anthropogenic release, and serious biological effects. This review consolidates current understanding of their natural and industrial sources, environmental cycling, human exposure routes, and population-level vulnerabilities. It covers their toxicokinetics and toxicodynamics, emphasizing species-specific absorption, distribution, and injury mechanisms, including oxidative stress, thiol binding, mitochondrial dysfunction, endocrine disruption, and cancer risk. Clinical signs range from subtle neurocognitive impairment and kidney damage to severe acute poisoning. The review evaluates evidence-based approaches to risk assessment and biomonitoring, such as blood, urine, hair, and speciation tests, noting issues, including unvalidated provoked testing. Treatment focuses on removing exposure, providing nutritional support, and offering supportive care, with chelation therapy reserved for specific cases. It explains the chemistry, pharmacology, and roles of chelating agents—ALA, DMSA, DMPS, Cys, GSH, and physiologic thiols, comparing their effectiveness, limitations, and costs for various metals. Emerging therapies, precision toxicology, and public health strategies are discussed within a prevention-focused context. Unlike prior reviews focused primarily on toxic mechanisms or isolated clinical management, this review integrates mechanistic toxicology, biomarker interpretation and speciation, evidence-based clinical care, and ethical, cost-conscious decision-making within a single translational framework. This narrative review synthesizes foundational and contemporary literature published through 2025, with particular emphasis on studies published since 2000 that inform toxicokinetics, biomarker interpretation, diagnostics, clinical management, and prevention. Full article

Traditional chemical hair dyes are associated with potential health risks, while botanical alternatives are often hampered by poor stability and limited color longevity. In this study, discarded squid ink was used to prepare bionic hair colorants of high performance. By synergizing ultrasound disruption with enzymatic hydrolysis, the crude ink aggregates were transformed into highly uniform squid ink melanin nanoparticles (SIMNPs) with size and zeta potential of ~174 nm and −37.5 mV, respectively. This effectively improved the solubility but reduced the steric limitation of natural melanin. To overcome the weak affinity between melanin and human hair, a biomimetic interface where Fe(III) ions act as supramolecular bridges was further engineered to stably bind the SIMNPs to hair keratin. Under optimized conditions (pH 8.0, 45 °C, and 80 min), the dyed hair achieved a natural deep black with a total color difference (ΔE*) of 68.79 ± 0.29, which was maintained at 63.19 ± 0.27 even after 13 consecutive water washing cycles. Unlike destructive oxidative dyes, this SIMNP dyeing system assisted by coordination-driven assembly preserved the native α-helical architecture and disulfide bond networks of hair keratin. Furthermore, the deposited SIMNP layer effectively protected hair fibers from ultraviolet (UV) damage due to its powerful UV-shielding capacity. Crucially, in vitro and in vivo evaluations confirmed the exceptional biosafety of this formulation, demonstrating robust cellular tolerance and absence of murine skin irritation. The work demonstrates a green, low-damage paradigm for the development of bio-based hair colorants of high performance and presents a promising pathway for the high-value utilization of marine by-products. Full article

Skin and its appendages form an integrated system of ectodermal mini-organs that rely on Wnt signaling for lifelong homeostasis and regeneration; yet, the pathway operates in a highly organ-specific manner in each compartment. In interfollicular epidermis, the Wnt activity is spatially graded, thus maintaining the balance between basal progenitor proliferation and terminal differentiation. The hair follicle is governed by an intrinsic oscillator based on cross-regulation between Wnt and BMP signaling, providing a cell-autonomous layer of control over hair cycle dynamics. Finally, the nail organ is characterized by the spatial compartmentalization of Wnt activity, with a distal matrix activation zone supported by specialized mesenchymal niche cells that sustain continuous nail plate growth and coordinate the digit tip regeneration. Understanding these divergent regulatory architectures provides a conceptual framework for targeted regenerative strategies aimed at enhancing repair in skin and its appendages. Therefore, in this review, we synthesize recent molecular studies on Wnt signaling in the adult skin, hair follicles, and nail mini-organs, highlighting appendage-specific features that underlie their distinct regenerative capacities. We further discuss how dysregulated Wnt signaling contributes to skin, hair, and nail pathologies such as alopecia, chronic wounds, excessive scarring, skin cancer, and nail deformations, and summarize the emerging strategies that target Wnt pathway to therapeutically enhance hair regrowth, wound repair, cancer treatment, and digit tip regeneration. Full article

Background/Objectives: Platelet-rich plasma (PRP)–based regimens are widely used in non-scarring alopecia, yet objective response is variable and clinic-ready predictors are lacking. We evaluated short-term trichoscopic outcomes in routine practice and tested whether baseline complete blood count–derived inflammatory status, quantified by the neutrophil-to-lymphocyte ratio (NLR), can stratify response under PRP-based therapy. Methods: We performed an ambispective observational cohort study (October 2024–October 2025) in an outpatient dermatology practice. The final analytic cohort included 129 patients allocated to four treatment groups: PRP alone (n = 54), PRP combined with microneedling-assisted Purasomes Hair & Scalp Complex (HCS50+, Dermoaroma; exosome-containing) (n = 33), PRP combined with microneedling-assisted Mesoaroma Hair Cocktail (scalp formulation; nutrient complex) (n = 24), and a nutrient complex alone (n = 18). Trichoscopy (FotoFinder ATBM; FotoFinder Systems GmbH, Bad Birnbach, Germany) was obtained at baseline (T1) and first follow-up (T2). Density response was defined as a ≥10% increase in total hair density and hair-cycle response as an anagen fraction increase ≥5 percentage points. Predictive analyses were prespecified and restricted to PRP-containing regimens, using logistic regression and a multilayer perceptron with repeated cross-validation for internal validation. Results: Across the full cohort (n = 129), total hair density and hair-cycle parameters improved from T1 to T2. In the PRP-containing subgroup (n = 111), baseline NLR strongly discriminated density responders (AUC 0.85, bootstrap 95% CI 0.77–0.91). In multivariable models, NLR remained independently associated with density response (OR 0.31 per 1-unit increase, 95% CI 0.20–0.48). Conclusions: In this cohort, baseline NLR was associated with discrimination of early trichoscopic response in PRP-based treatment of non-scarring alopecia. Using the Youden-derived cut-off (NLR = 2.202), patients with NLR > 2.202 had a higher risk of density non-response (72.1% vs. 4.7%), corresponding to a 15.49-fold increased failure risk in this cohort. These findings are exploratory and hypothesis-generating, and external validation and calibration are required before any routine clinical or decision-support use. Full article

Hair follicles are highly specialized mini-organs within the skin that drive the production of wool and cashmere, traits of major biological and economic importance in sheep and goats. Despite their microscopic size, hair follicles exhibit extraordinary regulatory complexity, integrating genetic programs with seasonal, endocrine, environmental, and epigenetic cues. Although transcriptional networks and signaling pathways underlying follicle morphogenesis and cycling have been extensively investigated, the post-transcriptional mechanisms that fine-tune these processes remain insufficiently understood. MicroRNAs (miRNAs) have emerged as pivotal post-transcriptional regulators that coordinate cell fate determination, lineage commitment, and tissue homeostasis. Growing evidence indicates that miRNAs play essential roles in hair follicle stem cell maintenance, proliferation, differentiation, apoptosis, and organ-level development, functioning through interconnected regulatory networks rather than isolated linear pathways. By modulating the expression of key follicle-determining genes and signaling components, miRNA-mediated regulation shapes follicle formation, cyclic regeneration, and fiber traits. In this review, we synthesize recent advances in miRNA research related to hair follicle biology, with a particular focus on wool- and cashmere-bearing mammals. We integrate findings across species to propose a systems-level framework in which miRNA networks interface with canonical signaling pathways and epigenetic mechanisms to orchestrate follicle development and regeneration. Conserved and species-specific regulatory principles are discussed to bridge fundamental follicle biology with practical applications in fiber production. Overall, this review highlights miRNAs as a critical yet previously underappreciated regulatory layer in hair follicle biology. A deeper understanding of miRNA-mediated control provides new conceptual insights into wool and cashmere development and offers a foundation for future molecular breeding and precision regulation strategies in livestock. Full article

Dynamic changes in gene and transcript expression represent a key factor in regulating the cyclical development of hair follicles. In this study, based on Nanopore sequencing (ONT-seq) data of skin tissue from three developmental stages (anagen (An), catagen (Cn), and telogen (Tn)) of Jiangnan cashmere goat hair follicles, this study presents a profile of candidate DETs implicated in cycle regulation by delineating their stage-specific expression patterns and dynamic expression trends from anagen to telogen. A large proportion of the candidate DETs were significantly enriched in functions related to fat synthesis, storage, or metabolism, with significance levels of p < 0.05 or p < 0.01. These significantly enriched DETs, which were generally upregulated from An to Cn or downregulated from Cn to Tn, support a model where accelerated intradermal fat deposition promotes the progression from An to Cn, while its subsequent decrease facilitates the transition from Cn to Tn. Concurrently, our results also suggest a potential role for dynamic changes in AS patterns in regulating the hair follicle cycle. This regulatory role of AS patterns is potentially mediated through affecting genes related to lipid synthesis/metabolism or cell structure/interaction. Notably, a broader range of fat synthesis, storage, or metabolism-related transcripts showed significant differential expression (p < 0.05) in the An vs. Cn group. Ultimately, by establishing this candidate DET profile, we aim to provide fresh perspectives for deciphering the complex molecular regulation of the hair follicle cycle and to identify new targets for genetically enhancing or molecularly breeding cashmere traits in cashmere goats. Full article

Cashmere goats produce high-value fine fibers derived from secondary hair follicles; however, the molecular mechanisms underlying this trait remain incompletely understood. In this study, comparative transcriptome sequencing was performed on skin tissues from Inner Mongolian cashmere goats and normal goats to characterize gene expression differences associated with cashmere fiber production. High-quality RNA-seq data with strong mapping efficiency and reproducibility were obtained across all samples. Differential expression analysis identified 1543 significantly differentially expressed genes (DEGs) between cashmere and normal goats, including genes involved in hair follicle morphogenesis, epidermal differentiation, cell proliferation, and extracellular matrix organization. Multivariate analyses showed a clear transcriptomic separation between fleece types, indicating that fleece phenotype is the primary driver of variation in global gene expression. Functional enrichment revealed significant involvement of the Wnt, MAPK, and PI3K–Akt signaling pathways, and several biologically relevant regulators of hair follicle development and hair cycle control, including FGF5, SOX9, LHX2, and VDR, were differentially expressed. Gene fusion events were rare and showed no group specific patterns, whereas alternative splicing was widespread, with exon skipping as the predominant splicing event in goat skin. Overall, these results provide quantitative transcriptomic evidence linking signaling regulation, follicle development, and structural differentiation to secondary hair follicle activity and cashmere fiber formation, offering candidate genes and molecular pathways for functional validation and molecular breeding in cashmere goats. Full article

Melatonin, an indoleamine crucial for regulating circadian rhythms, sleep–wake cycles, and immune–endocrine homeostasis, is present in biological fluids at extremely low concentrations, making its quantification analytically challenging. This narrative review provides a critical comparative assessment of current methodologies for melatonin determination across various biological matrices—plasma, urine, saliva, breast milk, and hair. The discussed techniques include immunoassays, colorimetric and spectrophotometric methods, chromatographic–mass spectrometric platforms (LC–MS/MS, UHPLC–MS/MS), and emerging biosensors. Each approach is evaluated regarding analytical sensitivity, specificity, reproducibility, cost, and clinical applicability. While immunoenzymatic and colorimetric techniques offer accessible, low-cost solutions for large-scale or preliminary studies, LC–MS/MS remains the benchmark for reference analysis, providing sub-picogram detection limits and multiplexing capability. However, its high cost, procedural complexity, and inter-laboratory variability limit routine implementation. New developments, including molecularly imprinted polymers, dispersive microextraction, and nanomaterial-based biosensors, suggest a shift toward hybrid, sustainable, and portable analytical platforms. By synthesizing recent methodological advances and identifying key limitations, this review aims to guide researchers and clinicians in selecting the most appropriate analytical approach for clinical, pharmacological, and circadian biomonitoring applications. Full article

Hair aging, a complex physiological process involving progressive hair thinning and loss of luster, is primarily driven by functional decline of hair follicle components and sebaceous glands due to cumulative oxidative stress. This decline manifests as dermal papilla cell (DPC) senescence, with reduced insulin-like growth factor-1 (IGF-1) secretion, impaired hair matrix keratinocyte proliferation, and decreased keratin synthesis. We investigated the restorative potential of poly-D,L-lactic acid (PDLLA) filler, a biostimulatory polymer with antioxidant properties, against these age-related changes. PDLLA filler treatment significantly reduced oxidative stress—as indicated by decreased 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels—in hydrogen peroxide-induced senescent human DPCs, alleviated cell-cycle arrest, and significantly upregulated IGF-1 secretion. Conditioned medium from PDLLA filler-treated DPCs stimulated proliferation and pan-keratin expression in senescent hair follicular keratinocytes (HFKs). Intradermal PDLLA filler injection in aged mice significantly reduced 8-OHdG levels, restored DPC proliferative capacity (indicated by proliferating cell nuclear antigen [PCNA] positivity), increased IGF-1 expression within the dermal papilla, and enhanced HFK proliferation in the hair matrix. Consequently, PDLLA filler treatment robustly upregulated hair cortex keratins (K35, K85) and inner root sheath markers (AE15, K25, K71), leading to improved cuticle integrity and the attenuation of follicular miniaturization. Senescence within sebaceous glands was also mitigated, as evidenced by increased PCNA and peroxisome proliferator-activated receptor gamma (PPAR-γ) expression, accompanied by enhanced hair shaft reflectivity and shine. Overall, PDLLA filler ameliorated senescence-associated phenotypes and restored senescence-associated functional decline, supporting its potential as an intervention for age-related hair thinning and quality deterioration. Full article

Male pattern baldness (MPB) is a highly prevalent condition with a complex, poorly understood molecular basis that limits therapeutic innovation. This study aimed to bridge the gap between statistical genetic associations and biological function by identifying and prioritizing causal proteins and pathways involved in MPB. Using data from 24,069 men in the UK Biobank, we performed a proteome-wide association study of 2911 plasma proteins with self-reported MPB severity via multivariable ordinal logistic regression, adjusting for age, Body Mass Index (BMI), ethnicity, lifestyle, socioeconomic factors, and testosterone levels. Significant proteins underwent pathway enrichment analysis. Genetic integration included MAGMA for gene-level aggregation and tissue prioritization, transcriptome-wide association studies (TWAS) with GTEx models, conditional fine-mapping, and validation in an independent scalp biopsy transcriptomics dataset (GSE90594). Druggability and pleiotropy were evaluated using databases and phenome-wide association studies. Forty-seven proteins were significantly associated with MPB severity, enriched in pathways involving epidermis development, hair cycle regulation, and cell adhesion. Multi-omic integration prioritized five independent candidate genes: CD38, FGF5, TACSTD2, DPEP1, and PLB1. Transcriptomic validation confirmed differential expression in balding scalp for CD38 (upregulated) and TACSTD2, PLB1 (downregulated). CD38 was identified as druggable with low pleiotropic risks. This study elucidates the molecular architecture of MPB, revealing novel biological pathways beyond canonical androgen signaling. By prioritizing promising non-hormonal targets like CD38, our findings provide a robust, evidence-based framework to guide the development of future therapeutic interventions for this common condition. Full article

The resource utilization of keratin waste has garnered significant attention, yet the processing of yak hair keratin in underdeveloped regions such as Tibet and Qinghai in China remains challenging. This study addresses these concerns by carbonizing yak hair keratin waste using a steam flash explosion (SFE) technique for 150 s, which is followed by activation with KOH at various ratios and subsequent to produce activated carbon (AC) samples. The AC was then combined with sodium alginate (Alg) at different ratios, pH and applied voltage to yield AC−Alg gel microbeads using an electrospinning method. The characterization of the AC and AC–Alg gel microbeads was conducted using SEM, BET, TG, and FT-IR analysis. In adsorption studies, AC−Alg_0.5U gel microbeads prepared with optimized conditions (pH 7, 11 kV, 19 G needle) were used to remove dyes (methylene blue (MB) and methyl orange (MO)) and antibiotic minocycline hydrochloride (MH). Various parameters such as temperature, pH, and adsorbent dose were optimized to obtain the maximum adsorption performance under model concentrations. The experimental results showed that the AC−Alg_0.5U gel microbeads can effectively adsorb MB and MO with adsorption capacities of 1038.9 mg/g and 206.2 mg/g, respectively. Moreover, the microbeads had the best adsorption performance for MH (1694.2 mg/g), with the kinetics most accurately represented by the pseudo-second-order kinetic model (R² = 0.999), and the isotherm followed the Langmuir model (R² = 0.984). The microbeads maintained a high adsorption capacity of 75% after six cycles. The composite gel microbeads not only utilize yak hair keratin waste but also will be used as durable and favorable adsorbents for the removal of pollutants. Full article