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- Injectable hydrogels for the delivery of nanomaterials for cancer combinatorial photothermal therapyPublication . Lima-Sousa, Rita; Alves, Cátia; Melo, Bruna L.; Costa, Francisco J. P.; Nave, Micaela; Moreira, André F.; Mendonça, António; Correia, I.J.; de Melo-Diogo, DuarteProgress in the nanotechnology field has led to the development of a new class of materials capable of producing a temperature increase triggered by near infrared light. These photothermal nanostructures have been extensively explored in the ablation of cancer cells. Nevertheless, the available data in the literature have exposed that systemically administered nanomaterials have a poor tumor-homing capacity, hindering their full therapeutic potential. This paradigm shift has propelled the development of new injectable hydrogels for the local delivery of nanomaterials aimed at cancer photothermal therapy. These hydrogels can be assembled at the tumor site after injection (in situ forming) or can undergo a gel–sol–gel transition during injection (shear-thinning/self-healing). Besides incorporating photothermal nanostructures, these injectable hydrogels can also incorporate or be combined with other agents, paving the way for an improved therapeutic outcome. This review analyses the application of injectable hydrogels for the local delivery of nanomaterials aimed at cancer photothermal therapy as well as their combination with photodynamic-, chemo-, immuno- and radio-therapies.
- Activity coefficients of aqueous Hydrochloric acid solutions up to a Molality of 6.0 mol kg-1 at temperatures from (5 to 45) °CPublication . Juusola, Pekka M.; Partanen, Jaakko; Vahteristo, Kari P.; Mendonça, António; Minkkinen, Pentti O.Simple three parameter activity coefficient equation originating from the DebyeHückel theory was used for the calculation of activity coefficients of aqueous hydrochloric acid at temperatures 5-45 °C up to a molality of 6 moI kg-I. N ew data from galvanic ce1ls without a liquid junction were used in the parameter estimations of this equation. These data consist of sets of measurements in the molality range 0.3-6.5 moI kg-I at temperatures 5, 15, 25, 35, and 45°C. It was observed that alI estimated parameters folIow very simple equations with respect to temperature. They are either constant or depend linearly on the temperature. The activity coefficient equation was tested with the celI potential difference data of Hamed and Ehlers (1933), ElIis (1916), Ákerlõf and Teare (1938), and Faita and Mussini (1964). It was observed that the most important data in these sets can be predicted welI by means of the activity coefficient equation. The activity coefficients obtained using the new equation were also compared to those obtained by means of the two-parameter Hückel and Pitzer equations presented by Partanen and Covington (2002) up to molality 2.0 moI kg-t, to those obtained by means of the Pitzer equations presented by Saluja et ai. (1986) and Holmes et ai. (1987), and to those obtained by means of the equation presented by Hamer and Wu (1972) for the temperature of 25°C.
- Plant-Based Beverages: Consumption Habits, Perception and Knowledge on a Sample of Portuguese CitizensPublication . Anjos, Ofélia; Pires, Patrícia C. P.; Gonçalves, Joana; Estevinho, Maria Letícia; Mendonça, António José Geraldes de; Guiné, Raquel P. F.Plant-based beverages (PBB) consumption has increased significantly worldwide due to an interest in vegetarian/vegan diets, taste preferences, health and ethical and environmental issues. Therefore, this study intends to investigate consumption habits, consumer preferences and consumers’ level of knowledge about PBB. In this study, a voluntary, anonymous questionnaire survey was applied to a sample of participants from Portugal. The sample was recruited by convenience, and therefore, the distribution among the groups was not even. Data analysis involved different statistical techniques: basic statistics, chi-square tests, factor analysis, cluster analysis and tree classification analysis. The results indicated that the most consumed PBB were almond, soy and oat beverages. The majority of consumers chose these beverages for nutritional and health reasons, while a smaller number consumed them as part of a vegetarian or vegan diet. The main motivations for consuming PBB are mainly associated with sustainability and health benefits. The results regarding the respondents’ knowledge about PBB revealed that a health-related profession was the most significant predictor. These results allowed us to conclude that the factors of nutrition, health, ethics and practice of a vegetarian/vegan diet influence the consumption of PBB. It was also concluded that being in a healthcare profession, along with age and professional status within this field, were significant factors influencing the level of knowledge about PBB.
- Electroepoxidation of natural and synthetic alkenes mediated by sodium bromidePublication . Inês, Massuquinini; Mendonça, António; Esteves, Ana P.; Mendonça, Dina; Medeiros, Maria J.Electroepoxidation of synthetic alkenes (styrene, trans-stilbene and trans-b-methylstyrene) and of some natural terpenes (limonene, terpinolene, geraniol, a-terpinene, g-terpinene and a-terpineol) mediated by sodium bromide was performed in MeCN:H2O (4:1) at platinum electrodes. The indirect electrochemical oxidation of the olefins led to the corresponding epoxides in yields ranging from 23% to 79%.
- Phenolic compounds: a novel approach to reduce egg allergenicity?Publication . Vapor, Alcides; Tomaz, Cândida T.; Mendonça, AntónioHen's egg allergy has been climbing in all countries due to eggs ubiquity in foodstuffs. This allergy is an IgE mediated reaction that affects mainly infants and young children. So far, the processes used to decrease the allergenicity of egg proteins, such as cooking, thermal processing, storage and enzymatic digestion have not been totally effective. Previous studies demonstrated that proteins form complexes with phenolic compounds, so the aim of this work was to analyze the effect of these compounds in ovalbumin (OVA) conformation and its possible application to reduce eggs allergenicity. OVA was incubated at different temperatures with phenolic compounds (caffeic, chlorogenic, ferulic, gallic and tannic acids; resveratrol and quercetin) and was analyzed by circular dichroism (CD), Attenuated Total Reflection–Fourier Transform Infra-Red (ATRFTIR) spectroscopy and fluorescence. Changes in the secondary structure of OVA were evidenced by CD and ATR-FTIR. Also, protein fluorescence decreased with increasing concentrations of phenolic compounds. The thermodynamic analysis suggested that electrostatic interactions are important in the binding process, and the quenching mechanism occur by contact. This was confirmed by docking where the phenolic compounds bind specifically to some regions of the protein, including those with the allergenic epitopes.
- Kolbe Electrosynthesis of 1,2-Di(bicyclo[2.2.1]heptan-2-yl)ethane and 1,2-DiphenylethanePublication . Mendonça, António; Inês, Massuquinini; Esteves, Ana P.; Mendonça, Dina; Medeiros, Maria J.Kolbe electrosynthesis, at low current densities, of 1,2-diphenylethane and 1,2-di(bicyclo[2.2.1]heptan-2-yl)ethane with 77 and 72% yields, respectively, is described.
- Activity coefficients in the evaluation of food preservativesPublication . Mendonça, António; Vaz, Margarida I. P. M.; Mendonça, DinaFood preservatives are used in very low concentrations. However, usually they are used in aqueous high ionic strength solutions. The Pitzer model allows activity coefficient determination in these cases. Without the knowledge of activity coefficients, activity or ‘correct concentration’ cannot be known. In this work, the activity coefficients of sodium chloride, potassium chloride and calcium chloride in pure solutions were calculated by the Debye H¨uckel theory and the Pitzer theory. The calculated values were compared with experimental values. Activity coefficients of pure sodium benzoate in aqueous mixed solutions with potassium chloride or calcium chloride were evaluated using the Pitzer model. The same evaluation can be done to more complex systems once all Pitzer parameters values for the ionic species are known.
- Breast cancer targeted photothermal therapy mediated by hyaluronic acid functionalized reduced graphene oxidePublication . Sousa, Ana Rita Lima; Diogo, Duarte de Melo; Alves, Cátia Gomes; Costa, Elisabete; Louro, Ricardo; Mendonça, António G.; Correia, I.J.The use of graphene-based nanomaterials in cancer photothermal therapy (PTT) is an emerging alternative to the currently available cancer treatments. In this regard, reduced graphene oxide (rGO) has been widely explored for cancer PTT due to its excellent photothermal capacity. However, rGO has some limitations, such as low colloidal stability and water insolubility, as well as absence of targeting capacity towards cancer cells. Herein, rGO produced by an environmentally- friendly method was functionalized with an amphiphilic polymer based on hyaluronic acid (HA-rGO) through hydrophobic-hydrophobic interactions for application in targeted breast cancer PTT. The functionalization improved rGO colloidal stability and cytocompatibility towards normal and breast cancer cells, as well as conferred targeting capacity towards CD44 overexpressing breast cancer cells. In addition, the photothermal effect mediated by HA-rGO upon laser irradiation reduced breast cancer cells’ viability. Overall, HA-rGO demonstrated a great potential for being used on-demand and selective treatment of breast cancer cells.
- Combining Photothermal‐Photodynamic Therapy Mediated by Nanomaterials with Immune Checkpoint Blockade for Metastatic Cancer Treatment and Creation of Immune MemoryPublication . Sousa, Rita Lima; Melo, Bruna L.; Alves, Cátia; Moreira, André; Mendonça, António; Correia, I.J.; Diogo, Duarte de MeloThe pursuit of effective treatments for metastatic cancer is still one of the most intensive areas of research in the biomedical field. In a not-so-distant past, the scientific community has witnessed the rise of immunotherapy based on immune checkpoint inhibitors (ICIs). This therapeutic modality intends to abolish immunosuppressive interactions, re-establishing T cell responses against metastasized cancer cells. Despite the initial enthusiasm, the ICIs were later found to be associated with low clinical therapeutic outcomes and immune-related side effects. To address these limitations, researchers are exploring the combination of ICIs with nanomaterial-mediated phototherapies. These nanomaterials can accumulate within the tumor and produce, upon interaction with light, a temperature increase (photothermal therapy) and/or reactive oxygen species (photodynamic therapy), causing damage to cancer cells. Importantly, these photothermal-photodynamic effects can pave the way for an enhanced ICI-based immunotherapy by inducing the release of tumor-associated antigens and danger-associated molecular patterns, as well as by relieving tumor hypoxia and triggering a pro-inflammatory response. This progress report analyses the potential of nanomaterial-mediated photothermal-photodynamic therapy in combination with ICIs, focusing on their ability to modulate T cell populations leading to an anti-metastatic abscopal effect and on their capacity to generate immune memory that prevents tumor recurrence.
- A Introdução à Qualidade no Currículo de Química Analítica: Necessidades e MotivaçãoPublication . Mendonça, AntónioA Qualidade na sociedade moderna é uma exigência, não só às empresas mas também aos profissionais. Deste modo, as exigências colocadas aos novos licenciados vão para além dos seus conhecimentos de Qualidade adquiridos nos currículos clássicos de Química Analítica. Existem excelentes manuais de Química Analítica, como o de Valcárcel [l] ou o de Kellner et ai. [2], que colocam o tema da Qualidade numa posição importante. Infelizmente, nem sempre é possível efectuar o estudo aprofundado da Qualidade no currículo de Química Analítica, sobretudo quando os alunos não pertencem a licenciaturas em Química ou em variantes desta, dado que existem outras matérias a ser leccionadas e que não podem ser menosprezadas. Valcárcel [l] sugere diferentes conteúdos a leccionar de acordo com o nível de compreensão desejado, que ocuparão pelo menos, 20 a 30 horas, o que corresponderia na prática à ocupação quase que exclusiva de uma disciplina semestral. Neste trabalho, apresenta-se uma proposta para a inclusão no currículo de Química Analítica de , licenciaturas, não nucleares em Química, de uma Introdução à Qualidade. Partindo de casos práticos justifica-se a necessidade de normalização e daí progride-se no sentido da Qualidade em Química, figura l. Espera-se deste modo motivar os alunos para a importância da Química Analítica no âmbito da Qualidade.