Characterization of the mechanical properties of the cortex region of human hair fibers by multiparametric atomic force microscopy mapping.

We show the benefit of the use of atomic force microscopy (AFM) in spectroscopy force mode (FV: force volume) for evaluation of the cosmetic active effectiveness in improving the mechanical properties of human hair fibers cortex region. For this, we characterized human hair fibers without and with chemical damage caused by bleaching process. Fiber and resin (embedding material) data were obtained simultaneously in the mapping in order to have the resin data as a reference to ensure a coherent comparison between data from the different fiber groups. Our AFM results, which were evaluated using statistical tests, demonstrated the degradation of fibers after bleaching, corroborating the findings of transmission electron microscopy analysis and the effectiveness of a cosmetic active ingredient in improving the Young's modulus (elastic modulus) (E) of the damaged fibers. We also found a radial decrease in the natural logarithm of Young's modulus ln(E) along the cross-section of the active group fiber, which is compatible with confocal Raman spectroscopy analysis by other authors, demonstrating variation of the active permeation with depth. We note that Young's modulus was also determined by a tensile tester (macro-scale technique), in which it was not possible to obtain statistically significant differences between the groups, evidencing the advantage of the FV-AFM analysis. We also found an increase in ln(E) accompanied by a decrease in maximum adhesion force between tip and sample (negative Pearson correlation coefficient). This result can be explained by the fact that structures composed of hydrophobic components have a higher Young's modulus than structures composed of hydrophilic components.

Propanediol (and) Caprylic Acid (and) Xylitol as a New Single Topical Active Ingredient against Acne: In Vitro and In Vivo Efficacy Assays.

In addition to dermatological complications, acne can affect the quality of life of individuals in numerous ways, such as employment, social habits and body dissatisfaction. According to our expertise, caprylic acid and propanediol would not have a direct action on Cutibacterium acnes. Despite this, we investigated the existence of a synergistic effect among xylitol, caprylic acid and propanediol as a mixture of compounds representing a single topical active ingredient that could benefit the treatment against acne. In vitro and in vivo assays were performed to challenge and to prove the efficacy of propanediol, xylitol and caprylic acid (PXCA) against acne. PXCA had its MIC challenged against C. acnes (formerly Propionibacterium acnes) and Staphylococcus aureus, resulting in concentrations of 0.125% and 0.25%, respectively, and it also developed antimicrobial activity against C. acnes (time-kill test). PXCA was able to reduce the 5-alpha reductase expression in 24% (p < 0.01) in comparison with the testosterone group. By the end of 28 days of treatment, the compound reduced the skin oiliness, porphyrin amount and the quantity of inflammatory lesions in participants. According to the dermatologist evaluation, PXCA improved the skin's general appearance, acne presence and size.

Efficacy of cosmetic formulations containing dispersion of liposome with magnesium ascorbyl phosphate, alpha-lipoic acid and kinetin.

The present study aimed to evaluate the photoprotective effects of cosmetic formulations containing a dispersion of liposome with magnesium ascorbyl phosphate (MAP), alpha-lipoic acid (ALA) and kinetin, as well as their effects on the hydration and viscoelastic skin properties. The photoprotection was determined in vitro (antioxidant activity) and in vivo on UV-irradiated hairless mouse skin. The hydration effects were performed with the application of the formulations under study on the forearm of human volunteers and skin conditions were analyzed before and after a single application and daily applications during 4 weeks in terms of transepidermal water loss (TEWL), skin moisture and viscoelastic properties. The raw material under study possessed free-radical scavenging activity and the formulation with it protected hairless mouse skin barrier function against UV damage. After 4 weeks of application on human skin, the formulation under study enhanced stratum corneum skin moisture and also showed hydration effects in deeper layers of the skin. Thus, it can be concluded that the cosmetic formulation containing a dispersion of liposome with MAP, ALA and kinetin under study showed photoprotective effects in skin barrier function as well as pronounced hydration effects on human skin, which suggests that this dispersion has potential antiaging effects.

Immediate and long-term effects of polysaccharides-based formulations on human skin

A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL), viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.

Uma nova tendência em formulações cosméticas é a utilização de matérias-primas biotecnológicas como os polissacarídeos de Klebsiella pneumoniae, que pode aumentar a renovação celular e melhor a hidratação e micro-relevo da pele. Por outro lado, o extrato vegetal de Myrtus communis contém diferentes polissacarídeos, que também podem proporcionar benefícios à pele. Assim, o objetivo do estudo foi a avaliação dos efeitos imediatos e em longo prazo, de formulações cosméticas contendo polissacarídeos obtidos por processo biotecnológico e/ou de extrato de M. communis por meio de análises objetivas e subjetivas. Três formulações contendo os polissacarídeos e um placebo foram aplicadas na pele dos antebraços de 40 voluntários. As medidas foram realizadas antes e após 2 horas da aplicação das formulações e após 15 e 30 dias de aplicações diárias em termos de hidratação da pele, perda transepidérmica de água (TEWL), viscoelasticidade e micro-relevo da pele. Para a análise subjetiva, os voluntários responderam um questionário a fim de obter-se informações sobre a percepção relativa à qualidade de cosméticos. Todas as formulações provocaram aumento da hidratação cutânea. As formulações que continham os polissacarídeos melhoraram a função barreira da pele, em curto e em longo prazo. A formulação contendo extrato de M. communis apresentou maior aceitação. Os resultados sugerem que o uso diário dos polissacarídeos avaliados é importante na proteção da função barreira da pele.

Influência da água termal e de seus oligoelementos na estabilidade e eficácia de formulações dermocosméticas / Influence of thermal water and its oligoelements in the stability and efficacy of dermocosmetics formulations

Introdução: a água termal vem sendo proposta como agente anti-inflamatório e hidratante leve. Posto que há rígido controle de qualidade e, portanto, dificuldade para sua extração do subsolo, um complexo de oligoelementos tem sido utilizado com finalidade equivalente. Objetivo: avaliar a estabilidade e a influência da água termal ou de seus oligoelementos em formulações cosmecêuticas, assim como os efeitos imediatos de sua aplicação na pele. Métodos: foram elaborados gel aquoso, gel-creme e emulsão acrescidos ou não de oligoelementos e submetidos à análise de estabilidade física. Na análise da eficácia, 15 voluntárias aplicaram nos antebraços as formulações que demonstraram melhor estabilidade.A avaliação objetiva dos efeitos imediatos e após duas horas, em relação à hidratação e textura da pele, foi realizada através de técnicas de biofísica e análise de imagem, antes e após a aplicação.A avaliação subjetiva foi obtida por questionário de percepção desses efeitos pelas voluntárias. Não foi avaliada a possível ação anti-inflamatória. Resultados: os géis foram considerados mais estáveis e selecionados para os testes de eficácia; também proporcionaram aumento do conteúdo aquoso do estrato córneo, e as águas apenas melhoraram a textura da pele. Conclusão: os resultados obtidos na avaliação subjetiva e objetiva foram coincidentes e sugeriram a utilidade do uso de cosmecêuticos com oligoelementos na hidratação da pele como coadjuvantes em tratamentos dermatológicos.

Background: It has been proposed that thermal water can be used as an anti-inflammatory and mild hydrating agent in the preparation of skincare formulations. However, due to the complex process and strict quality control associated with its extraction from the ground, an oligoelements complex that mimics the effects of thermal water on skin is being used instead. Objective:To evaluate the stability and effects of thermal water and its oligoelements in the formulation of cosmeceuticals, as well as their immediate effects on the skin. Methods: An aqueous gel, a gel cream and an emulsion were prepared with and without the addition of oligoelements and submitted to physical stability analysis.The more stable preparations were tested on study subjects' forearms. The objective evaluation of the effects on the skin's texture and hydration was conducted according to biophysical and image analysis techniques before, immediately after and 2 hours after application. Questionnaires assessed participants' subjective perceptions of the various formulations.The possible anti-inflammatory effects were not evaluated. Results: The effects of the more stable gel formulations were assessed on 15 study subjects.The gels increased the content of the aqueous corneum stratum, while the waters only produced an improvement of the skin's texture. Conclusion: The results obtained from the subjective and objective analyses coincided and suggested the usefulness of the oligoelements complex in cosmeceutical products for moisturizing the skin.

Avaliação do comportamento reológico de diferentes géis hidrofílicos / Rheologic behavior of different hydrophylic gels

O tipo de polímero empregado na formulação de gel pode influenciar no comportamento reológico e na estabilidade física do produto e até mesmo, afetar a aceitabilidade deste pelo consumidor. A reologia tem sido assunto de grande e crescente importância para as indústrias cosmética e farmacêutica, tendo em vista que a consistência e o espalhamento dos produtos devem ser reproduzidos de lote para lote, assegurando a qualidade tecnológica do produto acabado. O objetivo desta pesquisa foi determinar o comportamento reológico de diferentes géis hidrofílicos: dois geis preparados com polímeros dos ácidos carboxivinílicos e um com polímero do ácido poliacrílico. Para este estudo utilizou-se o reômetro Cone & Placa. As formulações estudadas foram estocadas nas temperaturas 25 e 40 °C e amostras destas foram analisadas nos tempos 1 e 28 dias. Pode-se verificar que a temperatura elevada influenciou na estabilidade física de todos os géis e que o gel preparado com ácido poliacrílico apresentou a maior pseudoplasticidade enquanto os constituídos de ácidos carboxivinílicos apresentaram maior tixotropia.