The influence of different nanocarriers on skin’s biophysical parameters

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2017Introduction & Aims: Nanotechnology is a new trend in cosmetology and lipid nanoparticles have shown higher degree of biocompatibility and versatility in this field compared to other systems. The aim of this research project was to evaluate the influence of three different systems containing lipid nanoparticles previously well characterized on skin hydration and transepidermal water loss (TEWL). Methods: Several formulations of lipid nanoparticles based systems (solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) with Dynasan® 114 (D114) or Glycerol monostearate (GMS) and nanoemulsions (NE)) were fully characterized (particle size, polydispersity index and zeta potential), and then incorporated into hydrogel form to study different skin parameters such as skin hydration and TEWL on forearms of six human volunteers. Results: The capacitance basal values of human volunteers before application of any hydrogel containing lipid nanoparticles were 31,48 (Control), 31,73 (SLN), 30,98 (NE), 30,42 (NLCD114) and 32,07 a.u. (NLCGMS). The TEWL basal values were 7,70 (Control), 7,55 (SLN), 7,72 (NE), 7,50 (NLCD114) and 7,67 g/h/m2 (NLCGMS). One hour after hydrogels` application, the capacitance values measured were 40,07 (Control), 43,20 (SLN), 41,22 (NE), 41,15 (NLCD114) and 44,15 a.u. (NLCGMS). At the same time, the TEWL values obtained were 6,58 (Control), 4,67 (SLN), 4,13 (NE), 3,90 (NLCD114) and 4,22 g/h/m2 (NLCGMS). Conclusion: The present study showed an increase in skin hydration after exposure to different systems of lipid nanoparticles (even not statistically significant). On the other hand, there was a statistically significant decrease in TEWL after that exposure, compared to the control. In this way, nanolipid systems, i.e. solid lipid nanoparticles, nanostructured lipid carriers and nanoemulsions, are promising systems to improve skin’s biophysical parameters in cosmetodermatology.Introdução & Objetivos: A nanotecnologia é uma nova tendência no ramo da cosmetologia e as nanopartículas lipídicas têm demonstrado um maior grau de biocompatibilidade e versatilidade nesta área, comparando com outros sistemas já bem conhecidos. Este projeto de investigação teve como objetivo principal a avaliação da influência de três sistemas diferentes de nanopartículas lipídicas previamente bem caracterizados ao nível de parâmetros biofísicos da pele, nomeadamente hidratação da pele e perda transepidérmica de água. Métodos: Diversas formulações de sistemas baseados em nanopartículas lipídicas (nanopartículas lípidicas sólidas (SLN), vetores lipídicos nanoestruturados (NLC) formulados com Dynasan® (D114) ou Monoestearato de glicerol (GMS) e nanoemulsões (NE)) foram rigorosamente caracterizadas (nomeadamente o tamanho das partículas, índice de polidispersão e potencial zeta), sendo depois incorporadas na forma de hidrogel para ser avaliada a influência destes nanosistemas lipídicos em diferentes parâmetros biofísicos da pele, como a hidratação da pele e a perda transepidérmica de água nos antebraços de seis voluntários. Resultados: Os valores basais de capacitância nos voluntários antes da aplicação de qualquer hidrogel contendo nanopartículas foram 31,48 (controlo), 31,73 (SLN), 30,98 (NE), 30,42 (NLCD114) e 32,07 a.u. (NLCGMS). Os valores basais da perda transepidérmica de água foram 7,70 (controlo), 7,55 (SLN), 7,72 (NE), 7,50 (NLCD114) e 7,67 g/h/m2 (NLCGMS). Os valores da capacitância, uma hora após a aplicação dos hidrogeles, foram 40,07 (controlo), 43,2 (SLN), 41,22 (NE), 41,15 (NLCD114) e 44,15 a.u. (NLCGMS) e os valores de perda transepidérmica de água medidos após o mesmo período de tempo foram 6,58 (controlo), 4,67 (SLN), 4,13 (NE), 3,90 (NLCD114) e 4,22 g/h/m2 (NLCGMS). Conclusão: O presente estudo demonstrou um aumento na hidratação da pele após exposição a diferentes sistemas de nanopartículas lipídicas, mesmo não tendo sido estatisticamente significativo. Por outro lado, houve uma diminuição estatisticamente significativa na perda transepidérmica de água após essa mesma exposição, comparativamente ao valor registado no hidrogel controlo. Desta forma, os nanosistemas lipídicos (nanopartículas lipídicas sólidas, vetores lipídicos nanoestruturados e nanoemulsões) são sistemas promissores ao nível da melhoria dos parâmetros biofísicos da pele em Cosmética e Dermatologia

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field