International Journal of Cosmetic Science最新文献

Objective: Sensitive skin is typically characterized by dryness, reactivity and inflammation, often associated with a compromised skin barrier and an imbalanced microbiome. This study aims to investigate the effects and mechanisms of fermented tea seed oil in improving sensitive skin, particularly focusing on the skin lipid barrier and microbiome.

Methods: Tea seed oil was fermented using biotechnology, and its lipid components were analysed both before and after fermentation. A double-blind, randomized, half-face controlled clinical trial was conducted on 25 Chinese young women with sensitive skin. Participants used a moisturizer containing 5% fermented tea seed oil or a base moisturizer for 4 weeks. Non-invasive methods were used to measure physiological parameters. Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and high-throughput gene sequencing technologies were employed to analyse skin lipids and the microbiome.

Results: Fifty-three differential lipids were identified by comparing the lipid profiles of tea seed oil before and after fermentation. The most significant increase was observed in DHA-CoA, which has the potential to improve skin lipid metabolism and enhance the skin barrier. The participants showed significant improvements in skin hydration, redness reduction and facial wrinkles. Lipidomics analysis revealed notable changes in the skin lipid profile before and after treatment, with 41 and 15 differentially expressed lipids identified in the test and control groups, respectively. Microbiome results indicated no significant alterations in the diversity or abundance of skin microbiota after treatment. Nevertheless, the composition of the skin microbiota demonstrated a beneficial shift, with Propionibacterium acnes being suppressed while Streptococcus increased. These microbial changes are associated with skin barrier repair as well as sensitivity and inflammation.

Conclusion: Fermented tea seed oil demonstrates notable clinical benefits for sensitive skin. It effectively regulates lipid metabolism and the composition of skin microbiota, thereby strengthening the lipid barrier and reducing the risk of potential inflammation. The increased presence of DHA-CoA in the fermented tea seed oil may serve as a key molecular contributor to its improved reparative efficacy.

Objective: To address the current lack of standardized tools for evaluating hair appearance in the beauty industry, this study presents a robust and accessible method for objectively quantifying hair fibre orientation using two-dimensional discrete Fourier transform (2D-DFT).

Methods: We analysed hair images of 120 Japanese women using 2D-DFT and extracted the principal orientation angle and anisotropy index by fitting an ellipse to the directional Fourier spectrum. The robustness of the method at the image scale was tested by evaluating its performance across various image resolutions.

Results: The proposed method accurately quantified hair orientation and showed consistent performance across differing image scales provided that individual hair fibres were visually distinguishable. As the method requires only standard digital images and basic computational processing, it is well suited for practical applications.

Conclusion: Our 2D-DFT-based approach offers a simple yet robust framework for analysing overall hair orientation. Although further validation is required for different hair types and local orientation analyses, this method provides a foundation for objective evaluation of hair appearance in cosmetic diagnostics and hair science research.

Objectives: Oat lipids are rich in ceramides. In this investigation, we analysed the delivery of a specific Oat Lipid Extract derived from Avena sativa, comprising 'skin identical' ratios of fatty acids, ceramides and cholesterol/sterol. This investigation is the first reported investigation of oat lipids utilizing Raman spectroscopy for the identification of oat ceramides from A. sativa supported by Lipbarvis®, transmission electron microscopy and immunofluorescence analysis.

Methods: Oil lipid class compositions were determined by single-dimension double-development high-performance thin-layer chromatography. Ceramide class profiling was carried out using liquid chromatography with tandem mass spectrometry. Raman spectra of lipids were obtained by confocal Raman spectroscopy and immunostaining on human skin explants following treatment for 5 days. Length of lipid lamellae was determined using Lipbarvis® transmission electron microscopy followed by immuno-histochemical analysis of hyaluronic acid and ceramides, on human skin following treatment for 56 days. Measurement of skin roughness (PRIMOS) and hydration (corneometer) were performed following treatment for 56 days.

Results: Gas-liquid chromatography and high-performance thin-layer chromatography profiling of Oat Lipid Extract, revealed that of the ceramide classes identified, skin identical sphingosine and phytosphingosine bases were present. Oat Lipid Extract has a typical total polar lipid content of 40 g kg^-1 of which 4 g kg^-1 ceramides, comprised ceramides/hydroxyceramides, gycosyl inositol phosphoryl ceramides and glucosylceramides. Raman profiling of Oat Lipid Extract was well correlated with stratum corneum and viable epidermis lipid profiles. Oat Lipid Extract induced a significant increase in neutral and polar lipid content. Lipbarvis® transmission electron microscopy and immunostaining showed significant increase in the length of the intercellular lipid lamellae and in the amount of hyaluronic acid and ceramides. Oat Lipid Extract significantly reduced skin roughness and increased skin hydration after 56 days of treatment.

Conclusion: Oat ceramides in the form of Oat Lipid Extract can be effectively delivered into the stratum corneum. The preliminary Raman and electron microscopy Lipbarvis® studies have given good insight into the possibility of Oat Lipid Extract mimicking the structure and function of the skin's barrier. The visible effect on the skin was observed with a decrease in skin roughness.

Objective: To develop and evaluate a novel silicone ionic gel (SIG) for personal care applications, designed to deliver enhanced texture, hydration, and compatibility with a wide range of cosmetic ingredients.

Methods: SIG was synthesized by swelling a fatty acid modified silicone elastomer in 68 wt% plant-derived solvent. The gel's architecture was engineered to form flexible, water-accessible channels. Performance was assessed through various complementary techniques including rheological testing, formulation studies, and skin hydration testing.

Results: SIG exhibited solid-like rheology, shear recovery, and surfactant-free incorporation of water and polyols. SIG-based formulations improved skin hydration by ~10% over PEG-based silicone gels. Demonstrated broad compatibility with hydrophilic and hydrophobic ingredients. Showed superior pigment dispersion without surface treatment, confirmed via optical microscopy.

Conclusions: SIG is a multifunctional gel platform offering unique texture, long-lasting sensory effects, enhanced moisturization, and formulation flexibility. Its compatibility with diverse cosmetic ingredients and ability to host structured water make it a promising candidate for next-generation skincare and cosmetic products.

Although some studies suggest the benefits of clay minerals in hair treatments, limited research has addressed their effects on the mechanical properties of hair fibres. This study investigates the incorporation of two commercial clays (designated A and B) into solid shampoo and conditioner formulations and evaluates their impact on the mechanical performance of hair fibres. X-ray fluorescence spectroscopy (XRF) analysis of the clays revealed a high silica content. X-ray diffraction (XRD) analysis identified montmorillonite and nontronite phases in clay A, characterizing it as bentonite. In contrast, clay B exhibited a predominant muscovite phase with secondary phases of illite and chlorite. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of typical vibrational modes associated with these clay minerals. UV-VIS spectroscopy showed strong absorption in the ultraviolet region for both clays. Formulations were developed with clay concentrations of 0.5%, 1.5%, and 3.0%, alongside a clay-free control. The addition of clays significantly enhanced the mechanical strength of the hair fibres, particularly clay B, which yielded a 94% improvement at 3.0% concentration. Combing force measurements also improved, indicating that the tested concentration effectively reduced frizz. Gloss measurements showed excellent enhancement across all formulations, with clay B increasing specular reflection by 56% at 3.0%. Overall, these findings demonstrate a promising potential for commercial clays to improve the mechanical and aesthetic properties of hair when incorporated into cosmetic formulations.

Background: In recent years, the psychological dimension of skin health has attracted increasing research interest, with established skin-related wellbeing metrics providing valuable insights for various conditions in clinical dermatology. This growing focus underscores the importance of developing sensitive, well-validated tools to better understand the emotional impact of skin health and appearance in healthy populations. The present article details the development and validation of such a metric, the SkinCARE Questionnaire (Condition and Affective Response Evaluation), and its relation to self-reported psychological stress and sleep health.

Method: 1184 participants (African American: n = 396, Hispanic: n = 392, Caucasian: n = 396; 886 females) completed the SkinCARE questionnaire, Sleep Health Index (SHI) and Perceived Stress Scale (PSS). The SkinCARE data was randomly divided into two equal samples for analysis: Sample 1 for exploratory factor analysis and Sample 2 for confirmatory factor analysis.

Results: Exploratory factor analysis supported a 24-item three-factor solution. Factor 1, Skin Social Impact, comprised 16 items that related primarily to how skin health impacted relationships with others and daily functioning. Factor 2, Skin Reactivity, comprised a further six items related to product reactions and skin breakouts. Factor 3, General Confidence, comprised a final 2 items. The three-factor structure was supported by confirmatory factor analysis. Further analysis demonstrated positive associations between good skin wellbeing, good quality sleep and low levels of stress.

Conclusion: The present scale is the first validated instrument designed to specifically measure the impact of skin health on emotional wellbeing in healthy populations. These data confirm the association between skin health and psychological wellbeing, and also a link to psychological wellbeing indicators. Future research should leverage the SkinCARE Questionnaire to examine and describe the effects of cosmetic skincare products on wellbeing.

Objective: Niacinamide is a well-established ingredient known for reducing hyperpigmentation by inhibiting melanosome transfer from melanocytes to keratinocytes. This study aimed to explore the potential synergistic effects of niacinamide and low pH in melanogenesis pathways and their impact on skin hyperpigmentation in clinical trials.

Methods: In vitro experiments were conducted using human melanocyte and/or keratinocyte cultures to investigate the effects of niacinamide at varying pH levels (neutral pH 7 and low pH 2.5-4). Melanin synthesis, melanocyte dendricity, melanosome transfer and melanosome degradation were assessed. Transcriptome analysis was performed to identify gene expression changes in human melanocytes. Additionally, vehicle-controlled facial clinical trials were conducted among Caucasian and Chinese females to evaluate the effects of niacinamide formulations at neutral and low pH.

Results: Niacinamide in neutral pH solutions and simple low pH solutions (without niacinamide) did not inhibit melanin synthesis or melanocyte dendricity, as expected. However, niacinamide in low pH solutions significantly inhibited both, indicating a synergistic interaction. Enhanced suppression of melanosome transfer and degradation was also observed, although these effects appeared to be additive to the effects of neutral pH niacinamide. Transcriptome analysis revealed downregulation of genes and pathways associated with melanogenic cytokine signalling, melanin biosynthesis, melanocyte dendricity and melanosome transfer for niacinamide in low pH formulation, but not niacinamide in neutral pH or simple low pH formulations (without niacinamide), further supporting the synergistic effect. A 4-week clinical trial among Caucasian females using 2% niacinamide formulation at pH 2.5 revealed a marked reduction in the appearance of facial spots compared to 2% niacinamide neutral pH or vehicle formulations. Similarly, an 8-week clinical trial conducted with Chinese females using 5% niacinamide formulation at pH 4 demonstrated significantly greater efficacy in both facial spot reduction and skin brightening in appearance than neutral pH niacinamide and vehicle formulations.

Conclusion: Our series of in vitro and clinical studies revealed groundbreaking findings on the role of pH modulation in enhancing the efficacy of niacinamide for hyperpigmentation reduction. By elucidating the synergistic mechanisms involved, this research paves the way for developing more effective treatments aimed at achieving a brighter and more uniform complexion safely.

Objective: This research assesses a novel cosmetic ingredient blending Lavandula angustifolia (lavender) flower extract and dipeptide-4 (LA-DP4, hereafter 'the blend'), for its potential to mitigate oxidative and glycation damage, boost autophagy and regulate circadian rhythms.

Methods: Using fibroblast, full-thickness skin models and ex vivo human skin, we measured markers like phosphorylated H2AX (γ-H2AX), reactive oxygen species (ROS), ATP, superoxide dismutase (SOD) and advanced glycation end products (AGEs), alongside effects on autophagic markers, melatonin production and extracellular matrix components.

Results: The blend significantly reduced γ-H2AX and ROS levels in UVA-stimulated fibroblasts, enhanced ATP and SOD levels, decreased AGEs in ex vivo tissues and improved tissue morphology in full-thickness models. Notably, it increased melatonin production and autophagic markers LC3a and LC3b, indicating a comprehensive role in skin health.

Conclusion: The blend addresses skin ageing by offering multifaceted benefits: antioxidant, anti-glycation, autophagy enhancement and melatonin production, marking a pioneering contribution to cosmetic ingredients that significantly boost melatonin production. Our findings advance the understanding of in vitro and ex vivo efficacy testing methods for these properties, aiding cosmeceutical development.

Objective: The systemic absorption of active ingredients in commercial sunscreens has raised safety concerns. This has created a need for advanced delivery systems that can enhance efficacy while minimising skin penetration. A promising solution is the encapsulation of sunscreen agents within microcapsules. The objective of this study is to demonstrate a simple and controllable method based on microfluidics for the preparation of sunscreen microcapsules with high ultraviolet absorption, good thermal stability, enhanced monodispersity and improved UV absorption performance.

Methods: A microfluidics-assisted method was employed to encapsulate a typical chemical UV filter, octyl methoxycinnamate (OMC), within biodegradable poly(lactic acid) (PLA) microcapsules using a commercial Corning Advanced-Flow microreactor. The effects of residence time on the morphology, size, encapsulation efficiency (EE) and loading capacity (LC) of the microcapsules were examined through comprehensive characterisation. Sun protection factor (SPF), UV stability and skin penetration of the microcapsules were also assessed, with release kinetics investigated by different models.

Results: The microfluidics-prepared microcapsules exhibited a uniform spherical morphology with adjustable sizes (10-38 μm), high encapsulation efficiency (>95%) and loading capacity (>22%). Compared to microcapsules prepared by the homogenisation method, the microfluidics-prepared ones displayed improved monodispersity and UV absorption performance. These improvements arise from microfluidics' precise control over droplet formation and narrow residence time distribution. Moreover, formulations containing OMC-loaded microcapsules achieved a 113% increase in SPF and significantly enhanced UV stability, along with a 50% reduction in skin permeation of OMC.

Conclusions: This study highlights the significant potential of microfluidics encapsulation for producing uniform sunscreen microcapsules with enhanced efficacy, stability and safety. By minimising systemic absorption while improving UV protection, this approach meets growing regulatory and consumer demands for safer, high-performance sunscreen formulations. These findings offer valuable insights for advancing next-generation cosmetic products.

Objectives: Innovation is considered a determining factor in the highly competitive environment of the cosmetic industry to introduce products while creating new needs. The goal of the study consisted of developing a highly natural and minimalist emulsion with sensorially pleasant skin application highlighted by an innovative ingredient based on a Ca²⁺ double cone vector system. The desired product characteristics include a creamy, white texture that is not too greasy or excessively whitening, with rapid skin penetration to facilitate its use for skin treatment.

Methods: To determine the ideal composition of the emulsion, a design of experiment (DoE) based strategy was applied in two steps: a screening step followed by optimisation. The screening step aimed to identify the key potential ingredients and process parameters that have a significant impact on the rheological and textural properties of the emulsion. The optimisation step provided the final emulsion formula with the desired physicochemical parameters and sensory characteristics.

Results: After rheological and sensory analysis, the screening of different ingredients revealed that the combination of 0.8% xanthan gum as the thickening agent (TA), glyceryl stearate citrate and polyglyceryl-3 stearate and hydrogenated lecithin as surfactant S1, and 1% of a mixture of C15-19 alkane (plant-based and renewable) - coco-caprylate/caprate as the sensory agent (SA1) provided the best sensorial qualities for the emulsion. The study demonstrated that the deflocculating rod met one of optimisation's target criteria through its process effect.

Conclusion: Based on DoE, the final formulation resulted in a visually white formulation that was neither too greasy nor excessively whitening and highly penetrative of the skin, offering a comfortable face or body cream application for adults and children.