Browsing by Issue Date, starting with "2020-10-19"
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- Relações Públicas na Construção da Imagem Institucional: Práticas e Ferramentas EstratégicasPublication . Tavares, Sandra Helena Pereira; Estevão, Cristina Maria SantosO presente trabalho aborda a temática “Relações Públicas na Construção da Imagem Institucional”, como principal responsável pelas diversas tarefas na construção da comunicação e da imagem de qualquer instituição. A boa imagem de uma instituição é aquela que define o posicionamento da instituição na sociedade. Ter uma imagem positiva é algo que toda organização almeja ter, pois tendo uma imagem positiva na sociedade, significa que o publico confia e atende a filosofia da organização. O trabalho tem como objetivo conhecer as práticas e ferramentas estratégicas que o Gabinete de Relações Públicas (GRP) da Universidade da Beira Interior (UBI) utiliza para trabalhar e transmitir uma boa imagem da instituição, tornando-a um fator de vantagem competitiva. Para a realização deste trabalho utilizou-se uma pesquisa exploratória de cunho qualitativo, tendo como objeto de estudo prático o Gabinete de Relações Públicas (GRP). Os dados foram obtidos através de fontes bibliográficas, observação e da aplicação de uma entrevista, utilizando uma metodologia baseada num estudo de caso. A instituição (UBI) apresenta uma boa prática em boas ferramentas de comunicação com enfoque nos seus colaboradores usando métodos inovadores, para atrair os públicos mantendo a competência dos seus trabalhadores.
- Tecnologia e emoções: antes e após reabilitação auditiva com aparelho auditivo (estudo preparatório)Publication . Murta, Ana Rita Teixeira; Souza, José António Menezes Felippe de; Nunes, Rui Manuel RibeiroA perda auditiva é um problema de saúde pública que afeta cerca de 10% da população portuguesa. Manifesta-se na vida pessoal, familiar, social e laboral, levando muitos dos indivíduos a experiências de emoções negativas como o medo, irritação, frustração, embaraço, entre outros. As tecnologias desenvolvidas para Reabilitação Auditiva, como os aparelhos auditivos, permitem atenuar o impacto da perda auditiva. Nesta pesquisa usouse as questões emocionais do questionário HHIE, em 10 indivíduos, antes e após o processo de reabilitação auditiva com sistemas auditivos bilaterais Widex Evoke para avaliar as diferenças emocionais no momento imediatamente antes do processo e dois meses após início do processo. Os resultados demonstram que é mais frequente sentir ansiedade, frustração e embaraço numa perda auditiva e que após o processo de reabilitação auditiva há redução das emoções de embaraço, frustração, diminuição, ansiedade e isolamento.
- Development and functionalization of gold nanoparticles with silica coating for application in cancer therapyPublication . Gonçalves, Ariana Soraia Carreira; Correia, Ilídio Joaquim Sobreira; Moreira, André Ferreira; Rodrigues, Ana Carolina FélixCancer is one of the leading causes of death worldwide and its incidence is expected to continue to increase over the next few decades. Such is explained by the non-specific toxicity and reduced therapeutic efficacy displayed by conventional treatments currently used in the clinic, namely surgery, chemotherapy, and radiotherapy. Particularly, chemotherapeutic agents are rapidly degraded and present a reduced solubility and selectivity to cancer cells. Among the new therapeutic approaches that have been developed, the application of nanomaterials capable of mediating a photothermal effect (i.e. increasing the temperature in response to a light stimulus with a specific wavelength), to induce the cancer cell deaths have been gaining increased attention. Among the several nanomaterials applied in photothermal therapy (PTT), gold core silica shell (AuMSS) nanoparticles presented excellent physicochemical properties that allow their application as photothermal and drug delivery agents. Different parameters of the gold core (e.g. size, shape) can be optimized to improve the photothermal capacity of these nanoparticles, and consequently their therapeutic efficacy. Additionally, the combination of AuMSS nanoparticles with other materials and molecules can also improve their photothermal effectiveness. However, despite the high therapeutic potential of AuMSS nanoparticles, their clinical application is hampered by their reduced circulation time in the bloodstream and lack of specificity to the tumoral tissue. Taking this into account, the research work developed during the second year of my MSc aimed to develop a new surface functionalization for rod-shaped AuMSS nanoparticles, based in biofunctional polymers to increase both its half-life in the bloodstream and internalization by cancer cells. For this purpose, the rod-shaped AuMSS nanoparticles were chemically modified with Polyethyleneglycol methyl ether (PEG-CH3) and Gelatin (GEL). The PEG-CH3 was chosen due to its amphiphilic nature and high solubility, which reduces the protein adsorption on the nanoparticles’ surface and consequently increases its blood circulation time. On the other hand, GEL is a natural polymer that contains arginine-glycine-aspartic acid (RGD) amino acid sequences with specificity for receptors overexpressed in cancer cells. Simultaneously, the encapsulation of IR780 was also tested for the first time in AuMSS nanoparticles to increase the photothermal and photodynamic capacity, and consequently its therapeutic potential. The obtained results demonstrated that the functionalization of rod-shaped AuMSS nanoparticles with GEL and PEG-CH3 polymers led to a neutralization of the surface charge from -23 to -7.46 mV. The successful incorporation of the polymers on nanoparticles surface was also confirmed by thermogravimetric analysis (TGA) and by Fourier transform infrared spectroscopy (FTIR). The in vitro studies demonstrated the biocompatibility of the different nanoformulations when in contact with cancer cells (cervical cancer) and healthy cells (fibroblasts) up to the maximum tested concentration of 200 µg.mL-1 . Additionally, the AuMSS functionalization with GEL increased their internalization by cancer cells without affecting their photothermal capacity. Otherwise, it was also observed that the encapsulation of IR780 resulted in an enhanced photothermal capacity of AuMSS/T-PEG-CH3/T-GEL nanoparticles and increased the generation of reactive oxygen species (ROS) upon irradiation with a NIR laser. Finally, the AuMSS/T-PEG-CH3/T-GEL nanoparticles were capable of effectively inducing the death of cancer cells. In summary, the obtained results confirm the successful functionalization of AuMSS nanoparticles with the GEL and PEG-CH3. Additionally, the potential of the AuMSS/IR780 combination was also demonstrated, where this nanosystem can simultaneously perform PTT and photodynamic therapy (PDT), which translates to an enhanced anticancer capacity.
- Development of multifunctional graphene oxide based nanomaterials for cancer therapyPublication . Melo, Bruna Daniela Lopes; Diogo, Duarte Miguel de Melo; Correia, Ilídio Joaquim Sobreira; Sousa, Ana Rita LimaBreast cancer remains as one of the deadliest diseases affecting the worldwide population. The high mortality rate exhibited by this disease can be attributed to the limitations of the treatments currently in use in the clinic (e.g. radiotherapy, chemotherapy), which display a low therapeutic efficacy and induce adverse side effects in patients. Therefore, there is an urgent demand for innovative therapeutic approaches that can enhance breast cancer survival rates. Recently, nanomaterials’ mediated Photothermal Therapy (PTT) has been showing promising results for cancer treatment. This therapeutic modality employs nanostructures that, due to their specific set of physicochemical characteristics, can accumulate at the tumor site. Afterwards, this zone is irradiated with Near Infrared (NIR) light and the tumor-homed nanomaterials induce a local temperature increase (hyperthermia) that can induce damage to cancer cells. Among the several nanomaterials with potential for cancer PTT, Graphene Oxide (GO) has been extensively investigated due to its absorption in the NIR. After interacting with this radiation, GO produces a temperature increase that can cause damage to cancer cells. In addition, this nanomaterial has an aromatic matrix that can be used to encapsulate a wide variety of compounds, thus having a great versatility. However, the direct application of GO in cancer PTT is limited by two factors: i) the low colloidal stability of GO, which causes its precipitation in biological fluids, and ii) the poor photothermal capacity of GO, which leads to the use of high doses/intense radiation in order to achieve an adequate therapeutic effect. In this MSc research work, GO was functionalized with an albumin based amphiphilic coating containing Sulfobetaine Methacrylate (SBMA) brushes (SBMA-g-BSA) and was loaded with IR780, with the intent to improve its colloidal stability and photothermal capacity, respectively. The results revealed that GO functionalized with SBMA-g-BSA (SBMA-BSA/GO) presents an adequate size distribution and cytocompatibility for cancer-related applications. When in contact with biologically relevant media, the size of the SBMA-functionalized GO derivatives only increased by 8 % after 48 h. In the same condition and period, the non-SBMA functionalized GO (BSA coated GO) suffered a 31 % increase in its size. By loading IR780 into SBMA-BSA/GO (IR/SBMA-BSA/GO), the nanomaterials’ NIR absorption increased by 5.6-fold. In this way, the IR/SBMA-BSA/GO could produce a up to 2-times higher photoinduced heat than SBMA-BSA/GO. In in vitro cell studies, the combination of NIR light with SBMA-BSA/GO did not induce photocytotoxicity on breast cancer cells. In stark contrast, the interaction of IR/SBMA-BSA/GO with NIR light caused the ablation of cancer cells (cell viability < 2 %). Overall, IR/SBMA-BSA/GO displays a greatly improved colloidal stability and phototherapeutic capacity, being a promising hybrid nanomaterial for application in the PTT of breast cancer cells.
- Development of multifunctional IR780 based nanomaterials for cancer therapyPublication . Leitao, Miguel Marques; Diogo, Duarte Miguel de Melo; Correia, Ilídio Joaquim Sobreira; Alves, Cátia GomesBreast cancer is a common cause of death among women. This scenario is in part explained by the limitations presented by the treatments currently used in the clinic (e.g. radiotherapy, chemotherapy), which display a low therapeutic efficacy and induce adverse side effects. In this way, it is necessary to develop innovative strategies that propel the breast cancer therapy efficacy. Among the different therapeutic strategies under investigation, cancer photothermal therapy mediated by nanomaterials has been showing promising results. This type of therapy takes advantage from the nanomaterials’ physico-chemical properties, that enable their tumor accumulation. Subsequently, the tumor zone is irradiated with Near Infrared (NIR; 750-1000 nm) light and the tumor-homed nanomaterials absorb this energy, releasing it as heat that causes damage to cancer cells. From the plethora of nanomaterials with potential to be applied in cancer photothermal therapy, Graphene Oxide (GO) is a promising candidate due to its NIR absorption and loading capacity. However, as-synthesized GO lacks colloidal stability, i.e., it precipitates when in contact with biological fluids. On the other hand, GO displays a modest photothermal capacity, requiring the use of high doses or intense radiation to achieve the desired therapeutic effect. In the work developed during my MSc, GO was functionalized with an amphiphilic polymer containing [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) brushes and was loaded with IR780 (a NIR photoabsorber), for the first time, to improve its colloidal stability and phototherapeutic capacity, respectively. The obtained results revealed that the SBMA-functionalized GO displays a suitable size distribution, neutral surface charge and an appropriate cytocompatibility. Furthermore, the SBMA-functionalized GO exhibited an improved colloidal stability in biological relevant media (at least up to 48 h), while GO without SBMA functionalization promptly precipitated in the same conditions. By loading IR780 into the SBMA-functionalized GO, its NIR absorption increased by 2.7-fold (at 808 nm), leading to a 1.2-times higher photothermal heating. In in vitro cell studies, the conjugation of NIR irradiation with SBMA-functionalized GO could reduce breast cancer cells’ viability to 73 %. In stark contrast, by combining IR780 loaded SBMA-functionalized GO and NIR radiation, the cancer cells’ viability decreased to 20 %. Overall, the IR780 loaded SBMA-functionalized GO nanomaterials have promising properties for application in breast cancer phototherapy.
- Evaluation of the antioxidant action of the G protein-coupled estrogen receptorPublication . Bernardino, Ana Carolina de Matos; Baltazar, Graça Maria FernandesThe brain is characterized by a high metabolism and contains several easily oxidizable substances such as amines and lipids, resulting in exposure to high levels of oxidative stress. In Parkinson's disease (PD), oxidative stress has been shown to be correlated with lipid peroxidation, inflammation, mitochondrial dysfunction and aggregation of a-synuclein (asyn). This demonstrates that oxidative stress can be one of the triggers of Parkinson's disease, as it is capable of inducing a series of pathogenic mechanisms characteristic of the disease, contributing to its progression. In this sense, the identification of mechanisms that help reducing oxidative stress may be an interesting strategy for controlling the progression of the disease. Since 17ß-estradiol exerts neuroprotective functions and has proved beneficial effects on several mechanisms such as neuroinflammation, excitotoxicity, among others, we assessed whether the selective activation of the G protein-coupled estrogen receptor (GPER), characterized by being involved in rapid non-genomic actions of 17ßestradiol, can exert a neuroprotective effect associated with the modulation of oxidative stress. With this objective, we developed an in vivo study with mice injected with 6-OHDA, which were later submitted to subcutaneous or intranasal treatment with the GPER agonist, G1. We evaluated how the selective activation of the receptor can contribute to the reversion of oxidative stress. To this end, several behavioral tests were performed to evaluate motor function, such as Grip Test, Rotarod and Open Field Test, and relative mRNA levels of antioxidant enzymes were measured by real-time PCR (RT-PCR). From the behavioral tests, it was possible to conclude that the 6-OHDA-injection was not capable of affecting motor behavior, since the results obtained with the Rotarod test, and the total distance travelled obtained with the Open field Test did not present significant differences. On the other hand, it was possible to observe that the parameters related with anxious behavior were increased in animals injected with 6-OHDA, when compared with the control group. Therefore, it can be concluded that the toxin had no effect at the level of motor behavior, but induced changes in non-motor domains. Regarding the expression of antioxidant enzymes, although not significant, an increase in the mRNA levels of Gpx4 and Nrf2 was observed in 6-OHDAinjected mice. This increase suggests a protective mechanism aiming to limit oxidative stress. However, further studies are needed to confirm this hypothesis. Our results have shown effects exercised by the G1, when administered by the two delivery approaches. However, it was not possible to conclude whether the two types of G1 delivery have an antioxidant effect in the presence of a dopaminergic insult. In this sense, further studies would be necessary to confirm whether GPER activation is capable of modulating oxidative stress and whether this effect is related to its currently recognized neuroprotective effects.