Nanoemulsions containing plant oils: How do they influence hair treatment?

OBJECTIVE: Cosmetic and dermatological products, mainly the hair treatments, are projected to have remarkable growing in coming years. Nanotechnology, specifically nanoemulsions, has potential to be used in several hair products, owing to their beneficial properties. Concurrently, plant-derived cosmetics have become more popular over the years to consumers who prefer a safer, natural and sustainable approach. There is a lack of studies combining plant oils and nanotechnology for haircare formulations. In this work, different plant oil-loaded nanoemulsions were prepared to investigate the influence of their particle size, zeta potential and composition on hair treatment efficacy. METHODS: Coconut, olive and Abyssinian oils, alone or in combination, were loaded into nanoemulsions by high-pressure homogenization method (HPH). The mean particle size, polydispersity index and zeta potential were measured by the dynamic light scattering (DLS) method, and a stability test was performed for five months. A sensorial screening evaluation performed by the analyst and the combing test using Dia-Stron® instrumentation were applied on hair tresses treated by these nanoemulsions. RESULTS: The use of different plant oils for nanoemulsion resulted in distinct final particle sizes and zeta potential. However, results suggested no significant difference between them in hair tresses combing efficacy compared by Dia-Stron® instrument testing. Moreover, the plant-loaded nanoemulsions with increased concentration of cationic surfactant indicated a 50% reduction in combing force using this device when compared to control, in addition to better sensory results by screening test compared to other nanoemulsions and control. CONCLUSION: The composition of plant oils, particle size or zeta potential of the prepared nanoemulsions does not seem to significantly influence hair performance. Thus, we suggest that finding the right balance between cationic surfactant and plant oils may be the most appropriate path to develop effective nanoemulsions in hair treatment.

OBJECTIF: Les produits cosmétiques et dermatologiques, principalement les traitements capillaires, devraient connaître une croissance remarquable dans les années à venir. La nanotechnologie, en particulier les nanoémulsions, a le potentiel d'être utilisée dans plusieurs produits capillaires, en raison de leurs propriétés bénéfiques. Parallèlement, les cosmétiques d'origine végétale sont devenus plus populaires au fil des ans auprès des consommateurs qui préfèrent une approche plus sûre, naturelle et durable. Il existe un manque d'études combinant les huiles végétales et la nanotechnologie pour les formulations de traitement capillaire. Dans ce travail, différentes nanoémulsions contenant de l'huile végétale ont été préparées pour étudier l'influence de leur taille de particule, de leur potentiel zêta et de leur composition sur l'efficacité du traitement capillaire. MÉTHODES: Les huiles de noix de coco, d'olive et d'Abyssinie, seules ou en combinaison, ont été chargées dans des nanoémulsions par méthode d'homogénéisation à haute pression (HPH). La taille moyenne des particules, l'indice de polydispersité et le potentiel zêta ont été mesurés par la méthode de diffusion dynamique de la lumière (DLS), et un test de stabilité a été effectué pendant cinq mois. Une évaluation sensoriel réalisée par l'analyste et le test de peignage à l'aide de l'instrumentation Dia - Stron® ont été appliqués sur les cheveux traités par ces nanoémulsions. RÉSULTATS: L'utilisation de différentes huiles végétales pour la nanoémulsion a donné des tailles de particules finales et un potentiel zêta distinct. Cependant, les résultats n'ont suggéré aucune différence significative entre eux dans l'efficacité du peignage des cheveux par rapport aux tests d'instruments Dia-Stron®. De plus, la nanoémulsion chargée avec une concentration plus élevée de tensioactif cationique a indiqué une réduction de 50% de la force de peignage en utilisant ce dispositif par rapport au contrôle, et, le screening a montré de meilleurs résultats sensoriels par rapport aux autres nanoémulsions et contrôle. CONCLUSION: La composition des huiles végétales, la taille des particules ou le potentiel zêta des nanoémulsions préparées ne semblent pas influencer significativement les performances capillaires. Ainsi, nous suggérons que trouver le bon équilibre entre un tensioactif cationique et des huiles végétales peut être la voie la plus appropriée pour développer des nanoémulsions efficaces dans le traitement des cheveux.

Avaliação da atividade IMAO e antibacteriana de extratos de Mikania glomerata Sprengel

Neste trabalho avaliou-se a atividade antibacteriana e IMAO de extratos de diferentes polaridades de Mikania glomerata. A atividade antibacteriana foi medida frente à cepa multiresistente de Staphylococus aureus PI57, através das técnicas de bioautografia e antibiograma. A atividade IMAO foi medida utilizando uma suspensão de mitocôndrias. Mikania glomerata mostrou conter no extrato hexânico substâncias antimicrobianas. Os extratos hexânico e CH2Cl2 foram ativos frente à MAO-B, sem apresentarem atividade de inibição da MAO-A, enquanto o extrato metanólico apresentou atividade de inibição da MAO-A e MAO-B, sem seletividade.

Antibacterial and IMAO inhibition activities of different polarities extracts of Mikania glomerata were evaluated. The antibacterial activity was assayed against a multiresistant strain of Staphyllococus aureus PI57. The IMAO activity was measured with a suspension of mitochondrion. In the hexanic extract of Mikania glomerata substances with antibacterial activity were detected. Hexanic and CH2Cl2 extracts showed MAO-B inhibition activity while MAO-A inhibition activity was not detected. The methanolic extract showed non-selective inhibition activity of MAO-A and MAO-B.

[Nursing: idealism and realism. Perspectives of nursing students on the nursing profession]. / Enfermagem: idealismo x realismo. Perspectivas de formandos do curso de graduação de enfermagem sobre a profissão de enfermagem.

Exploratory and descriptive study with the following objectives: to identify the nursing students' feelings related to the undergraduate course and their perception towards the nursing profession. After the four-year course, 57.4% of students perceived nursing in a positive way as a profession for the future, valued, recognised, compensating even with some limitations. However, 25% of students still perceived nursing as a mechanical, manual and sacrificed profession, with a limited scientific vision and with a gap between theory and practice and as a consequence a lower recognition by the society. If current trends are maintained, the nurse's value would be much greater in the next decades within the Brazilian society according to 61% of respondents.