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Synthetic polymers scaffolds often need to be coated with extracellular matrix (ECM) proteins to improve cell adhesion. For cultivated meat applications, coating should be avoided since it is necessary to eliminate expensive and animal-derived components. As cellulose acetate nanofibers is a low-cost cellulose-derived material, that induces cell adhesion and proliferation, we investigated its use associated with a bioactive annatto extract, a food-dye and potential meat preservative, as scaffolds for cultivated meat. Here, the bioactive electrospun nanofibers were evaluated through morphological, mechanical and biological characterizations. The results revealed that the scaffolds were porous with no specific alignment and average fiber diameter of 420±212 nm. Molecular analyzes revealed that in contrast to cellulose acetate scaffold, annatto-loaded cellulose acetate scaffold favor a proliferative state of C2C12 mouse skeletal myoblasts. SEM microscopy images suggests that the nanofiber substrates can sustain long-term culture of the cells, up to 28 days. These results suggest that the combination of cellulose acetate fibers loaded with annatto extract may be an interesting economical alternative for support long-term muscle cells culture with potential application as a scaffold for cultivated meat and muscle tissue engineering.

Although originally discovered inducing important biological functions in the nervous system, repulsive guidance molecule a (RGMa) has now been identified as a player in many other processes and diseases, including in myogenesis. RGMa is known to be expressed in skeletal muscle cells, from somites to the adult. Functional in vitro studies have revealed that RGMa overexpression could promote skeletal muscle cell hypertrophy and hyperplasia, as higher efficiency in cell fusion was observed. Here, we extend the potential role of RGMa during C2C12 cell differentiation in vitro. Our results showed that RGMa administrated as a recombinant protein during late stages of C2C12 myogenic differentiation could induce myoblast cell fusion and the downregulation of different myogenic markers, while its administration at early stages induced the expression of myogenic markers with no detectable morphological effects. We also found that RGMa effects on skeletal muscle hyperplasia are performed via neogenin receptor, possibly as part of a complex with other proteins. Additionally, we observed that RGMa-neogenin is not playing a role as an inhibitor of the BMP signalling in skeletal muscle cells. This work contributes to placing RGMa as a component of the mechanisms that determine skeletal cell fusion via neogenin receptor.

Animals with muscle hypertrophy phenotype are targeted by the broiler industry to increase the meat production and the quality of the final product. Studies characterizing the molecular machinery involved with these processes, such as quantitative trait loci studies, have been carried out identifying several candidate genes related to this trait; however, validation studies of these candidate genes in cell culture is scarce. The aim of this study was to evaluate SAP30 as a candidate gene for muscle development and to validate its function in cell culture in vitro. The SAP30 gene was downregulated in C2C12 muscle cell culture using siRNA technology to evaluate its impact on morphometric traits and gene expression by RNA-seq analysis. Modulation of SAP30 expression increased C2C12 myotube area, indicating a role in muscle hypertrophy. RNA-seq analysis identified several upregulated genes annotated in muscle development in treated cells (SAP30-knockdown), corroborating the role of SAP30 gene in muscle development regulation. Here, we provide experimental evidence of the involvement of SAP30 gene as a regulator of muscle cell hypertrophy.

Background: The repulsive guidance molecule a (RGMa) is a GPI-anchor axon guidance molecule first found to play important roles during neuronal development. RGMa expression patterns and signalling pathways via Neogenin and/or as BMP coreceptors indicated that this axon guidance molecule could also be working in other processes and diseases, including during myogenesis. Previous works have consistently shown that RGMa is expressed in skeletal muscle cells and that its overexpression induces both nuclei accretion and hypertrophy in muscle cell lineages. However, the cellular components and molecular mechanisms induced by RGMa during the differentiation of skeletal muscle cells are poorly understood. In this work, the global transcription expression profile of RGMa-treated C2C12 myoblasts during the differentiation stage, obtained by RNA-seq, were reported. Results: RGMa treatment could modulate the expression pattern of 2,195 transcripts in C2C12 skeletal muscle, with 943 upregulated and 1,252 downregulated. Among them, RGMa interfered with the expression of several RNA types, including categories related to the regulation of RNA splicing and degradation. The data also suggested that RGMa hyperplasia effects could be due to their capacity to induce the expression of transcripts related to cell-cell adhesion, while RGMa effects on muscle hypertrophy might be due to (i) the activation of the mTOR-Akt independent axis and (ii) the regulation of the expression of transcripts related to atrophy. Finally, RGMa induced the expression of transcripts that encode skeletal muscle structural proteins and members of the signalling pathways associated with GEF and Rho/Rac, common secondary signals of skeletal muscle hypertrophy, and the canonical pathway of the RGMa/Neogenin signalling. Conclusions: These results provide comprehensive knowledge of skeletal muscle transcript changes and pathways in response to RGMa.

Odontogenesis is guided by a complex signaling cascade in which several molecules, including FGF2-4, ensure all dental groups development and specificity. Most of the data on odontogenesis derives from rodents, which does not have all dental groups. Didelphis albiventris is an opossum with the closest dentition to humans, and the main odontogenesis stages occur when the newborns are in the pouch. In this study, D. albiventris postnatals were used to characterize the main stages of their molars development; and also to establish FGF2, FGF3 and FGF4 expression pattern. D. albiventris postnatals were processed for histological and indirect immunoperoxidase analysis of the tooth germs. Our results revealed similar dental structures between D. albiventris and mice. However, FGF2, FGF3 and FGF4 expression patterns were observed in a larger number of dental structures, suggesting broader functions for these molecules in this opossum species. The knowledge of the signaling that determinates odontogenesis in an animal model with complete dentition may contribute to the development of therapies for the replacement of lost teeth in humans. This study may also contribute to the implementation of D. albiventris as model for Developmental Biology studies.

Dissertação de Mestrado em Engenharia Electrotécnica e de Computadores Os avanços e inovações tecnológicas fornecem novas e melhores formas de integrar as funcionalidades e benefícios dos dispositivos eletrónicos na vida do ser humano no sentido de complementar muitos aspetos e atividades que estão presentes no seu dia-a-dia. Um enorme contributo para este facto são as tecnologias wearable. Com o rápido desenvolvimento tecnológico que todos os dias presenciamos, os wearables são capazes de diminuir progressivamente a distância que separa o Homem da tecnologia, muito devido à sua fácil integração em diferentes áreas que beneficiam da sua conveniência, conforto e utilidade. Um ótimo exemplo são os alcoolímetros wearable. A oportunidade de aferir a taxa de alcoolemia a qualquer hora com a conveniência de um dispositivo wearable é não só útil como de extrema importância, trazendo grandes progressos na prevenção de acidentes rodoviários. A presente dissertação descreve a implementação de um alcoolímetro smartwatch wearable complementado por uma aplicação móvel que possibilita a rápida e fácil estimativa da taxa de alcoolemia por analogia à quantidade de álcool detetado na respiração. O sistema final mostrou resultados bastante consistentes e proporcionais, cuja precisão foi confirmada através da sua comparação com o aparelho actualmente utilizado pelo comando da Polícia de Segurança Pública de Vila Real. Advances and technological innovations provide new and better ways to integrate the features and benefits of electronic devices in human life in order to complement many aspects and activities. Wearable technology represents a major contribution to this fact. With the fast technological development that we witness everyday, wearables can increasingly reduce the distance between mankind and technology, manly due to their easy integration in different areas that benefit from their convenience, comfort and utility. A great example are the wearable breathalysers. The opportunity to test the alcohol level at any time with the convenience of a wearable device is not only useful but also extremely important, bringing great progress in preventing traffic accidents. This thesis describes the implementation of a wearable breath analyzer inside a smartwatch that uses a mobile application that enables quick and easy estimation of alcohol rate by analogy with the level of alcohol detected in the breath. The final system showed consistent and proportional results, whose accuracy was confirmed by comparison with the system currently used by the Public Security Police of Vila Real.

Dissertação de Mestrado em Engenharia Biomédica A análise e modelação dos sinais fisiológicos para melhorar o desempenho desportivo de atletas, tanto profissionais como amadores, está a ganhar terreno. Este facto ocorre devido à incessante procura das pessoas se manterem em forma com o objectivo de obter a melhor qualidade de vida possível. Um dos parâmetros fisiológicos em destaque ao longo desta dissertação é o lactato. Este é um dos indicadores bioquímicos mais utilizado no treino desportivo porque assinala a transição entre o metabolismo aeróbico e anaeróbico. Contudo, a sua monitorização continua a ser possível, quase exclusivamente, através de métodos invasivos, como através de amostras de sangue, uma vez que as técnicas não-invasivas descritas na literatura são pouco precisas. Métodos de medição da impedância do tecido biológico, com o intuito de avaliar o lactato no corpo humano, pode ser uma técnica, não-invasiva, alternativa. Durante este trabalho é feita uma pequena introdução à impedância elétrica e às diversas aplicações da bioimpedância. Para se entender as propriedades elétricas do tecido biológico, foi criado um Analog Front End (AFE) baseado no circuito integrado AD5933 para analisar a evolução da bioimpedância ao longo de uma ampla gama de frequência. O desempenho do AFE é testado através de um modelo equivalente dos tecidos biológicos, com recurso a diversas componentes discretas, no intuito de se compreender se o circuito criado permite a monitorização de sinais fisiológicos, e posteriormente, a monitorização do lactato. The analysis and modeling of physiological signals to improve performance in athletes, both professional and amateur, is gaining ground today. This is due to the incessant demand of people to keep in shape with the goal of achieving a better quality of life. One of the physiological parameters highlighted throughout the dissertation is lactate. It is one of the most used biochemical indicator in sports training because it indicates the transition between aerobic and anaerobic metabolism. However, its monitoring is still possible through invasive methods, such as blood samples. The use of the bioimpedance measurement method may be an alternative to a noninvasive technique in order to evaluate lactate in the human body. During this work, it is shown an introduction to electrical impedance and to the various applications of bioimpedance. In order to understand the electrical properties of biological tissue, an Analog Front End (AFE) based on an integrated circuit AD59933 is designed to analyze the evolution of bioimpedance over a wide frequency range. The performance of the AFE is tested using an electrical circuit based on one model of biological tissues, using several discrete components, in order to understand if the circuit created allows the monitoring of physiological signals, and later, the lactate monitoring.

Dissertação de Mestrado em Engenharia Eletrotécnica e de Computadores A interação de fármacos é uma área da farmacologia com bastante interesse de estudo, pois é possível combinar fármacos no sentido de descobrir novas terapias mais eficientes com menor toxicidade para o doente. O efeito da mistura de dois componentes pode ser aditivo (o efeito da combinação é igual à soma dos efeitos dos fármacos isolados), antagónico (é necessária maior quantidade de fármacos na mistura para atingir o mesmo efeito isoladamente), ou sinérgico (para obter o mesmo efeito, na mistura a dose dos fármacos é menor que a dose isolada de cada fármaco). Para a determinação do efeito existente na combinação de fármacos existem vários métodos desenvolvidos, como por exemplo o princípio do efeito mediano de Chou e Talalay e o método de Greco que combina métodos mais antigos num novo método mais completo. Na presente dissertação é apresentada uma nova aplicação informática, InterPharm, desenvolvida em MatlabR, que permite aos investigadores analisar o efeito existente na combinação de dois fármacos em determinada terapia. Foram feitas experiências para diferentes combinações de fármacos e os resultados produzidos são semelhantes aos obtidos por outros softwares já existentes. The drug-drug interaction is an area of pharmacology with great interest of study because it is possible to combine drugs in order to discover new therapies more effective with less toxicity to the patient. The effect of the mixture of two components may be additive (the effect of the combination is equal to the sum of the effects of the individual drugs), antagonistic (requires more amount of drug in the mixture to achieve the same effect alone) or synergistic (for the same effect in mixing the dose of drugs is less than the dose of each drug alone). To determine the effect of drug combination there are several developed methods such as the principle of the median-effect of Chou and Talalay and Greco’s method that combines the oldest methods in a new and more complete method. In this thesis is presented a new software application, InterPharm developed in MATLAB, which allows researchers to analyze the effect on the combination of two drugs in certain therapy. Experiments were made for different drug combinations, and the results are similar to those obtained by other existing software.

[This corrects the article DOI: 10.3389/fnut.2023.1297926.]., (Copyright © 2024 Santos, Guadalupe, Albergaria, Almeida, Moreira, Copola, Araújo, de Paula, Neves, Santos, da Silva, Jorge and Andrade.)