Search Results (184)

Background/Objectives: Natural oils are widely promoted and used around the world as part of skincare. Among them, extra virgin olive oil (EVOO) stands out for its broad range of organic compositions and well-known moisturizing properties. This study aimed to evaluate the effects of topically applied EVOO compared to petrolatum on skin barrier function (SBF) and microtopography. Methods: A within-person randomized clinical trial was conducted in healthy adult volunteers. EVOO and petrolatum were applied to defined areas on the volar forearm. Parameters related to the SBF, including stratum corneum hydration (SCH), transepidermal water loss (TEWL), temperature, and erythema, were assessed. The skin microtopography was evaluated through two approaches: (1) topographic parameters—surface roughness, desquamation, smoothness, and wrinkles; and (2) stratum corneum (SC) composition—corneocytes subtypes and the desquamation index (DI). The participants completed a tolerability questionnaire for each product. Results: A total of 54 participants (50% female; mean age: 28.57 ± 11.02 years) completed the study. Both EVOO and petrolatum significantly improved the SBF by increasing SCH and reducing erythema and skin temperature. Petrolatum additionally reduced TEWL. Regarding the skin microtopography, both products decreased the desquamation index and reduced the prevalence of mature corneocyte types (types 2–5). These effects were more pronounced with petrolatum. Notably, EVOO significantly increased the proportion of early-stage corneocytes (type 1). Conclusions: Both EVOO and petrolatum effectively enhanced the SBF and improved the microtopographic features of the skin. While petrolatum exerted a stronger occlusive effect by reducing TEWL and desquamation, EVOO uniquely promoted epidermal renewal by increasing epidermal turnover. Full article

The growing demand for sustainable and effective cosmetic ingredients has prompted renewed interest in winemaking by-products. Among these, grape stem (GS) extract remains relatively underexplored despite its rich content of phenolic compounds distinct from those found in more commonly studied grape seeds or skins. This study validates the potential of GS extract as a novel bioactive component in cosmetic cream formulations. Rich in antioxidant, antiaging, and depigmenting compounds—such as resveratrol, catechins, and phenolic acids—GS extract was incorporated into creams at concentrations ranging from 0.33% to 6.25%. The formulations were evaluated for physicochemical characteristics, texture, rheological behaviour, and biological activity. The results demonstrated that GS extract enhanced total phenolic and flavonoid content, as well as viscosity, firmness, and antioxidant capacity—although not always in a concentration-dependent manner. All formulations maintained appropriate pH values and microbiological stability. Accelerated stability tests (40 °C, 75% RH, 3 months) identified the 0.83% to 1.64% concentration range as the most stable, preserving phenolic content, viscosity, and bioactivity. Higher extract levels, in contrast, led to reduced formulation stability, coalescence, and diminished antioxidant performance over time. Notably, GS-enriched creams exhibited significant elastase and tyrosinase inhibition, with lower concentrations maintaining antiaging potential throughout storage. These findings not only demonstrate that the incorporation of GS extract into a cosmetic base preserves its biological functionality but also reinforce the unique value of grape stems as an untapped resource for cosmetic innovation. Overall, the study advances current knowledge by establishing formulation parameters for a stable, effective, and sustainable cream based on grape stem extract. Further studies are recommended to optimize extract concentration and investigate encapsulation strategies for enhanced bioactive delivery and long-term stability. Full article

Atopic dermatitis (AD) is a chronic inflammatory skin disorder marked by intricate interplay among skin barrier dysfunction, immune dysregulation, and microbial dysbiosis. While therapeutic advancements targeting T helper 2 (Th2) cytokines, such as interleukin (IL)-4 and IL-13, and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway have yielded promising outcomes, a significant proportion of patients still experience inadequate relief, particularly from persistent pruritus. Achieving minimal disease activity remains an unmet clinical priority and a cornerstone of effective AD management. This review provides an in-depth analysis of current therapeutic approaches and integrates findings from recent biologic studies, with a particular focus on innovative strategies under active investigation. These approaches include targeting components of the innate immune system, such as thymic stromal lymphopoietin (TSLP) and IL-1 family cytokines; the adaptive immune system, including OX40-OX40L interactions and Th17- and Th22-related cytokines; and mechanisms associated with pruritus, such as IL-31, histamine receptors, and neurokinin 1 receptor. Emerging insights underscore the transformative potential of personalized therapeutic regimens tailored to the distinct endotypes and severity of AD. Advances in deciphering the pathogenesis of AD are unlocking unprecedented opportunities for precision medicine, offering renewed hope for improved outcomes in this multifaceted and heterogeneous condition. Full article

Offshore wind turbines serve as critical infrastructure components in marine renewable energy systems, enabling sustainable energy extraction within offshore engineering frameworks. Monopile foundations for offshore wind turbines in deep-water environments are subjected to strong nonlinear wave actions. This study introduces a novel composite monopile foundation specifically designed for deep-sea applications, with its fully nonlinear hydrodynamic performance systematically investigated using potential flow theory. The novel hybrid monopile incorporates a concrete-filled double-skin steel tubular (CFDST) configuration to reduce pile diameter at water level. In the numerical model, the higher-order boundary element method (HOBEM) is implemented to resolve boundary value problems at each temporal iteration. Following numerical validation, nonlinear wave loading and run-up characteristics for the CFDST hybrid structure are quantified, while the limitations of Morison’s equation for large-scale structures under strongly nonlinear wave conditions are concurrently assessed. Results indicate that CFDST implementation effectively attenuates both nonlinear hydrodynamic forces and wave run-up amplitudes, enabling safer and more economical design approaches for deep-water offshore wind turbine foundations. Full article

As far as history tells, people have set efforts both to improve the conditions and to change the visual outfit of the skin, nails, and hair. The first information on nail cosmetics is found in ancient China and Egypt, where various nature-derived compositions were used for changing the colour of the nails. Nowadays more mechanically and chemically durable systems for nail polishes are elaborated. This review focuses on the latest achievements in the field of UV-curable nail polishes. Herein, the polymerization mechanisms of various systems (acrylates, as well as epoxides and thiols) occurring in nail polishes are described. Besides plausible side reactions of the polymerization process are characterized. Thus, the main drawbacks for forming a uniform, perfect layer are illuminated. For effective curing, the choice of photoinitiators may be crucial; thus, various types of photoinitiators as well as their main advantages and disadvantages are characterized. Ensuring effective adhesion between the substrate (human nail) and the polymer film is one of the challenges for the nail polish industry—thus the plausible interactions between the adhesion promoters and the keratin are described. Regarding the film-forming agents, a comprehensive overview of the composition of the traditional UV-curing nail polishes is provided, but the main emphasis is devoted to alternative, nature-derived film-forming agents that could introduce renewable resources into nail cosmetics. Additionally, this review gives short insight into the latest innovations in UV-curing nail cosmetics, like (1) nail polishes with improved pealability, (2) covalently polymer-bonded dyes and photoinitiators, thus reducing the release of the low-molecular compounds or their degradation products, and (3) UV-curing nail polishes as delivery systems for nail treatment medicine. Full article

The limited availability of primary normal human epidermal keratinocyte (NHEK) has hampered the large-scale implementation of skin models in biomedical, toxicological, and pharmaceutical research. Therefore, in this study, we aimed to establish an induced pluripotent stem cell (iPSC)-derived epidermal skin model that is not limited by donor type and cell lifespan, and evaluate whether it is equivalent to the primary NHEK-derived reconstructed epidermal skin model (RHE) for skin irritation testing. The results show that high expression of OCT4, SOX2, KLF4, c-MYC, and SSEA-4, TRA-1-60, TRA-1-81 indicated that iPSCs were successfully generated from human fibroblasts in vitro. The expression levels of ectoderm or KC marker genes CGB, IVL, KRT10, KRT14, TP63, and TBP were close to those of NHEKs. This result confirms that iPSCs were successfully differentiated into iPSC-KCs. The expression levels of iPSC-derived-RHE in FLG (60), AQP3 (151), CLDN1 (30.6), IVL (209), KRT5 (39.3), KRT10 (39.2), TSLP (99), IL-6 (53.1), IL-8 (79.4), and TNF-a (91.5) were significantly higher than those in RHE. These results indicate that iPSC-derived RHE has extremely strong vitality and renewal capacity. Meanwhile, there was no significant difference between iPSC-derived RHE and SkinEthic in predicting skin irritation, which means that our iPSC-derived RHE performed well in the test. iPSC-derived RHE can replace other skin models for skin irritation testing related to cosmetics. This technology has the potential to generate an unlimited number of genetically identical skin models and improve the reproducibility of experiments. Full article

How to elicit and harness regeneration is a major issue in wound healing. Skin injury in most amniotes leads to repair rather than regeneration, except in hair and feathers. Feather follicles are unique organs that undergo physiological cyclic renewal, supported by a dynamic stem cell niche. During normal feather cycling, growth-phase proximal follicle collar bulge stem cells adopt a ring configuration. At the resting and initiation phases, these stem cells descend to the dermal papilla to form papillary ectoderm and ascend to the proximal follicle in a new growth phase. Plucking resting-phase feathers accelerates papillary ectoderm cell activation. Plucking growth-phase feathers depletes collar bulge stem cells; however, a blastema reforms the collar bulge stem cells, expressing KRT15, LGR6, Sox9, integrin-α6, and tenascin C. Removing the follicle base and dermal papilla prevents feather regeneration. Yet, transplanting an exogenous dermal papilla to the follicle base can induce re-epithelialization from the lower follicle sheath, followed by feather regeneration. Thus, there is a stepwise regenerative strategy using stem cells located in the collar bulge, papillary ectoderm, and de-differentiated lower follicle sheath to generate new feathers after different levels of injuries. This adaptable regenerative mechanism is based on the hierarchy of stem cell regenerative capacity and underscores the remarkable resilience of feather follicle regenerative abilities. Full article

The dynamic development of various branches of medicine and pharmacy, along with the emergence of new preventive and alternative therapies for various diseases, creates opportunities for new solutions utilizing carriers of active substances. Their therapeutic effect may occur through direct contact with skin lesions or indirectly, where medicinal substances penetrate the capillary network in the deeper layers of the skin and reach the bloodstream. The aim of the research was to obtain carriers with a matrix consisting of two renewable-source polymers (chitosan and ethylcellulose) and a core material derived from Ginkgo biloba green leaf extract (GBE). The obtained ethylcellulose microcapsules with encapsulated chitosan nanoparticles with extract {Et[Ch(GB)NP]} were characterized with respect to size, shape, surface morphology (SEM microscopy), and active substance release kinetics (UV-VIS and mathematical release models). The kinetics of active substance release were analyzed using UV-VIS spectroscopy and mathematical release models. The released active components were assessed microbiologically for activity against six bacterial strains and two fungal strains, as well as chromatographically using HPLC-ESI-QTOF-MS/MS fingerprinting. The microcapsules with a dual polymer layer exhibited a slow release of the core material, which demonstrated microbiological activity. The strongest antimicrobial effects were observed against Klebsiella pneumoniae and Salmonella enteritidis, with a minimum inhibitory concentration (MIC) of 410 µg/mL. The release of the core material from the double-layer polymer structures was more efficient in a physiological saline environment, with the best fit for the extract release kinetics following a zero-order model (regression coefficient R² = 0.9939). The obtained microcapsules with a dual polymer layer show great potential for therapeutic applications in the medical industry. Their controlled release properties and antibacterial effectiveness make them a promising carrier for active substances in modern therapies. Full article

The field of wearable sensors has evolved with operating devices capable of measuring biomechanics and biometrics, and detecting speech. The transduction, being the conversion of the biosignal to a measurable and quantifiable electrical signal, is governed by a conductive organic polymer. Meanwhile, the conformality of skin to the substrate is quintessential. Both the substrate and the conductive polymer must work in concert to reversibly deform with the user’s movements for motion tracking. While polydimethylsiloxane shows mechanical compliance as a sensor substrate, it is of environmental interest to replace it with sustainable and degradable alternatives. As both the bulk of the weight and area of the sensor consist of the substrate, using renewable and biodegradable materials for its preparation would be an important step toward improving the lifecycle of wearable sensors. This review highlights wearable resistive sensors that are prepared from naturally occurring polymers that are both sustainable and biodegradable. Conductive polythiophenes are also presented, as well as how they are integrated into the biopolymer for sensors showing mechanical compliance with skin. This polymer is highlighted because of its structural conformality, conductivity, and processability, ensuring it fulfils the requirements for its use in sensors without adversely affecting the overall sustainability and biodegradability of resistive sensors. Different sustainable resistive sensors are also presented, and their performance is compared to conventional sensors to illustrate the successful integration of the biosourced polymers into sensors without comprising the desired elasticity and sensitivity to movement. The current state-of-the-art in sustainable resistive sensors is presented, along with knowledge of how biopolymers from different fields can be leveraged in the rational design of the next generation of sustainable sensors that can potentially be composted after their use. Full article

Abnormalities in epidermal keratinocyte proliferation are a characteristic feature of a range of dermatological conditions. These include hyperproliferative states in psoriasis and dermatitis as well as hypoproliferative states in chronic wounds. This emphasises the importance of investigating the proliferation kinetics under conditions of healthy skin and identifying the key regulators of epidermal homeostasis, maintenance, and recovery following wound healing. Animal models contribute to our understanding of human epidermal self-renewal. Human skin xenografting overcomes the ethical limitations of studying human skin during regeneration. The application of this approach has allowed for the identification of a single population of stem cells and both slowly and rapidly cycling progenitors within the epidermal basal layer and the mapping of their location in relation to rete ridges and hair follicles. Furthermore, we have traced the dynamics of the proliferation pattern reorganization that occurs during epidermal regeneration, underlining the role of YAP activity in epidermal relief formation. Full article

Background/Objectives: Depigmenting cosmetic products are a fast-growing segment of the health products market, driven by consumer demand to address skin hyperpigmentation. Simultaneously, interest in products with a reduced environmental impact is increasing. However, the potential environmental risks, especially in aquatic ecosystems, of depigmenting products remain unexplored. This study assesses the usage frequency of skin depigmenting agents in cosmetic products and compiles data on the biodegradability and acute aquatic toxicity of the most prevalent compounds. Methods: A market analysis of Portuguese pharmacies and parapharmacies in 2022 identified prevalent depigmenting agents. Scientific evidence on their biodegradability and acute aquatic toxicity was compiled, and when data was unavailable, in silico predictions were conducted. Results: The study identified the ten most-used depigmenting agents in cosmetic products, including hydroxy/keto acids, as well as vitamin C and derivatives, with a usage frequency surpassing 50%. While most were naturally derived and showed low environmental risk, synthetic and highly lipophilic depigmenting agents found in 35 of 70 products (ascorbyl tetraisopalmitate/tetrahexyldecyl ascorbate and resorcinol derivatives) showed a higher potential for environmental hazard. Conclusions: The findings underscore the need for further research on the presence of these cosmetic ingredients in aquatic ecosystems and a reassessment of regulatory frameworks concerning their environmental impact. Mitigation strategies should emphasize biodegradable alternatives, renewable sources, and molecular modifications to reduce toxicity while maintaining depigmenting efficacy and skin safety. This study provides original insights into commonly used depigmenting agents in the health products market and their chemical structures, offering valuable opportunities for innovation in chemical/pharmaceutical industries. Full article

Dermatophytes are commonly encountered pathogens in clinical practice causing superficial infections of the skin, hair, and nails. These pathogens are often found on animals such as livestock (e.g., cattle, rabbits) and pets (e.g., cats, hedgehogs) that can lead to spillover infections in human populations. Here, we reviewed published reports (2009–2024) of dermatophyte infections in animals and in humans with a history of animal contact. A literature search was completed in October 2024 using PubMed, Embase (Ovid), and Web of Science (Core Collection), which identified 250 articles. Generally, dermatophytes tend to infect younger animals with long hair and exhibit a species-specific host range. Microsporum canis was the most commonly reported species—linked to cats—that can cause tinea capitis, especially concerning the development of kerion in children. Trichophyton verrucosum is strongly associated with cattle. The Trichophyton mentagrophytes complex shows a diverse range of animal hosts, with rabbits being most frequently reported; however, T. mentagrophytes var. erinacei is almost exclusively isolated from hedgehogs, and T. mentagrophytes var. benhamiae is more commonly found on rodents (e.g., guinea pigs). Lastly, the geophilic Nannizia gypsea has been isolated from both dogs and cats. Managing dermatophyte zoonoses is an ongoing challenge, as healthcare providers may empirically treat with corticosteroids or antibacterial agents due to its atypical inflammatory appearance. Evidence of in vitro resistance against griseofulvin and fluconazole has been documented in multiple zoonotic dermatophyte species. Resistance development against terbinafine and itraconazole is also a possibility, although the number of reports is scarce. Under the principles of the One Health approach, research on human fungal diseases should take animal and environmental factors into account. A renewed call for increased testing efforts is warranted. Full article

Enzyme peels are an emerging and effective cosmetic technique for controlled skin exfoliation. Naturally occurring proteolytic enzymes such as bromelain, ficin, and papain have gained increasing attention as promising cosmetic and cosmeceutical ingredients due to their exfoliating and skin resurfacing properties. These enzymes catalyze the hydrolysis of keratin protein bonds, facilitate the removal of dead skin cells from the outermost layer of the epidermis, and promote cell turnover. The role of these enzymes in skin care is particularly noteworthy due to their gentle, yet effective, exfoliating action, their ability to improve the penetration of active ingredients, and their contribution to skin renewal and regeneration. While proteolytic enzymes are traditionally extracted from fruit pulp, recent research highlights fruit by-products such as pineapple peels, fig latex, and papaya peels, as sustainable and environmentally friendly sources. These by-products, which are often discarded in the food and agricultural industries, are rich in enzymatic activity and bioactive compounds, making them valuable alternatives for cosmetic applications. Their use is in line with the principles of the circular economy. They contribute to waste prevention while improving the availability of effective enzymatic exfoliants. This review provides a comparative analysis of bromelain, ficin, and papain, highlighting their different biochemical properties, their efficacy in cosmetic formulations, and their common mechanisms of action. In addition, the extraction processes from fruit by-products, their incorporation into skin care formulations, and their potential for sustainable cosmetic applications are examined. The results underline the growing importance of proteolytic enzymes, not only as exfoliating agents, but also as multifunctional bioactive components in next-generation cosmetic products. Full article

Nanofluids, with their enhanced thermal properties, provide innovative solutions for improving heat transfer efficiency in renewable energy systems. This study investigates a numerical simulation of bioconvective flow and heat transfer in a Williamson nanofluid over a stretching wedge, incorporating the effects of chemical reactions and hydrogen diffusion. The system also includes motile microorganisms, which induce bioconvection, a phenomenon where microorganisms’ collective motion creates a convective flow that enhances mass and heat transport processes. This mechanism is crucial for improving the distribution of nanoparticles and maintaining the stability of the nanofluid. The unique rheological behavior of Williamson fluid, extensively utilized in hydrometallurgical and chemical processing industries, significantly influences thermal and mass transport characteristics. The governing nonlinear partial differential equations (PDEs), derived from conservation laws and boundary conditions, are converted into dimensionless ordinary differential equations (ODEs) using similarity transformations. MATLAB’s bvp4c solver is employed to numerically analyze these equations. The outcomes highlight the complex interplay between fluid parameters and flow characteristics. An increase in the Williamson nanofluid parameters leads to a reduction in fluid velocity, with solutions observed for the skin friction coefficient. Higher thermophoresis and Williamson nanofluid parameters elevate the fluid temperature, enhancing heat transfer efficiency. Conversely, a larger Schmidt number boosts fluid concentration, while stronger chemical reaction effects reduce it. These results are generated by fixing parametric values as $0.1<\varpi <1.5, 0.1<\mathit{Nr}<3.0, 0.2<\mathrm{Pr}<0.5, 0.1<\mathit{Sc}<0.4, \mathrm{and} 0.1<\mathit{Pe}<1.5.$ This work provides valuable insights into the dynamics of Williamson nanofluids and their potential for thermal management in renewable energy systems. The combined impact of bioconvection, chemical reactions, and advanced rheological properties underscores the suitability of these nanofluids for applications in solar thermal, geothermal, and other energy technologies requiring precise heat and mass transfer control. This paper is also focused on their applications in solar thermal collectors, geothermal systems, and thermal energy storage, highlighting advanced experimental and computational approaches to address key challenges in renewable energy technologies. Full article

Mesenchymal stem cells (MSCs) are a family of multipotent stem cells that show self-renewal under proliferation, multilineage differentiation, immunomodulation, and trophic function. Thus, these cells, such as adipose tissue-derived mesenchymal stem cells (ADSCs), bone marrow-derived MSCs (BM-MSCs), and umbilical cord-derived mesenchymal stem cells (UC-MSCs), carry great promise for novel clinical treatment options. However, the challenges associated with the isolation of MSCs and the instability of their in vitro expansion remain significant barriers to their clinical application. The plasma membrane-spanning P-glycoprotein ATP-binding cassette subfamily B member 5 positive MSCs (ABCB5⁺ MSCs) derived from human skin specimens offer a distinctive advantage over other MSCs. They can be easily extracted from the dermis and expanded. In culture, ABCB5⁺ MSCs demonstrate robust innate homeostasis and a classic trilineage differentiation. Additionally, their ability to modulate the recipients’ immune system highlights their potential for allogeneic applications in regenerative medicine. In this review, we primarily discuss the differentiation potential of ABCB5⁺ MSCs and their perspectives in regenerative medicine. Full article