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- Ciclodextrinas: formação de complexos e sua aplicação farmacêuticaPublication . Oliveira, Rita; Santos, Delfim; Barata, PedroO número de moléculas com problemas de solubilidade, biodisponibilidade e permeabilidade tem vindo a aumentar. As ciclodextrinas são oligossacarídeos cíclicos com uma cavidade central hidrófoba, cuja estrutura permite formar complexos de inclusão estáveis com diversos fármacos. A complexação com ciclodextrinas permite optimizar os diversos sistemas transportadores constituídos por este tipo de fármacos, assim como solucionar problemas devidos a propriedades indesejáveis como instabilidade, más características organolépticas ou potencial irritação. The number of molecules with problems of solubility, bioavailability and permeability is increasing. Cyclodextrins are cyclic oligosaccharides with a hydrophobic central cavity, whose structure can form stable inclusion complexes with various drugs. Complexation allows the optimization of drug delivery of such drugs, and to solve problems due to undesirable properties such as instability, poor organoleptic characteristics or irritation.
- Influence of gut microbiota dysbiosis on brain function: a systematic reviewPublication . Almeida, Cátia; Oliveira, Rita; Soares, Raquel; Barata, PedroBackground: For almost a century it has been recognized that human possess a varied and dens microbial ecosystem called the human microbiota, yet we are still beginning to understand many of the roles that these microorganisms play in human health and development. It is thought that under certain circumstances such as dysbiosis, the microbiota can cause diseases, where the central nervous system (CNS) has an important relevance and where the “gut-brain axis” will play a major role. Aims: This review investigated the influence of the gut microbiota on brain function, trying to demonstrate whether dysbiosis influences CNS diseases or whether it is the disease that causes dysbiosis, highlighting the existing literature within this field. Methods:We performed a systematic literature search in EMBASE, PubMed, and Cochrane combining the terms “gut microbiota,” “dysbiosis,” and “CNS diseases” to identify those whom reported some influence or relation between dysbiosis of gut microbiota and CNS diseases. For the present systematic review, we only included systematic reviews or meta-analysis. Results: The EMBASE, PubMed, and Cochrane were systematically searched, considering only systematic reviews or metaanalysis. Nine studies comprising 705 articles were included in this review. Those 9 systematic reviews consist in 2 about autism spectrum disorder, 1 in dementia, 1 in depression, 2 in autoimmune diseases, 1 in schizophrenia, and 2 in some altered brain function. Available data characterizing several neural diseases demonstrate a significant correlation between dysbiosis and CNS diseases, strengthen the evidence that dysbiosis of gut microbiota may correlate with abnormalities in CNS patients. Conclusions: Although there is a clear need for more investigations to better understand the role of the gut microbiota in CNS diseases, the modulation of the nervous system by the microbiota is clear, continuing to be the subject of continuous research. We need to fully understand the mechanisms by which the microbiota interacts with the human brain, and therefore what’s the connection between dysbiosis and pathologies such depression, dementia, autism, or schizophrenia.
- Chapter 5: Stimuli-responsive nanosystems for drug-targeted deliveryPublication . Lopes, Carla Martins; Barata, Pedro; Oliveira, Rita
- Antiangiogenic and antioxidant in vitro properties of hydroethanolic extract from açaí (Euterpe oleracea) dietary powder supplementPublication . Costa, Raquel; Azevedo, Daniela; Barata, Pedro; Soares, Raquel; Guido, Luís F.; Carvalho, Daniel O.The Euterpe oleracea fruit (açaí) is a promising source of polyphenols with health-promoting properties. To our knowledge, few studies have focused on the influence of açaí phytochemicals on angiogenesis, with a significant impact on cancer. This study aimed at investigating the phytochemical profile of a purple açaí hydroethanolic extract (AHE) obtained from a commercial dietary powder supplement by high-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry, and evaluate its in vitro effects on distinct angiogenic steps during vessel growth and on oxidative markers in human microvascular endothelial cells (HMEC-1). The phenolic profile of AHE revealed the presence of significant levels of anthocyanins, mainly cyanidin-3-O-rutinoside, and other flavonoids with promising health effects. The in vitro studies demonstrated that AHE exerts antiangiogenic activity with no cytotoxic effect. The AHE was able to decrease HMEC-1 migration and invasion potential, as well as to inhibit the formation of capillary-like structures. Additionally, AHE increased antioxidant defenses by upregulating superoxide dismutase and catalase enzymatic activities, accompanied by a reduction in the production of reactive oxygen species. These data bring new insights into the potential application of angiogenic inhibitors present in AHE on the development of novel therapeutic approaches for angiogenesis-dependent diseases.
- Overview on gastroretentive drug delivery systems for improving drug bioavailabilityPublication . Lopes, Carla Martins; Bettencourt, Catarina; Rossi, Alessandra; Buttini, Francesca; Barata, PedroIn recent decades, many efforts have been made in order to improve drug bioavailability after oral administration. Gastroretentive drug delivery systems are a good example; they emerged to enhance the bioavailability and effectiveness of drugs with a narrow absorption window in the upper gastrointestinal tract and/or to promote local activity in the stomach and duodenum. Several strategies are used to increase the gastric residence time, namely bioadhesive or mucoadhesive systems, expandable systems, high-density systems, floating systems, superporous hydrogels and magnetic systems. The present review highlights some of the drugs that can benefit from gastroretentive strategies, such as the factors that influence gastric retention time and the mechanism of action of gastroretentive systems, as well as their classification into single and multiple unit systems.
- The effects of ionizing radiation on gut microbiota, a systematic reviewPublication . Fernandes, Ana; Oliveira, Ana; Soares, Raquel; Barata, PedroBackground: The human gut microbiota is defined as the microorganisms that collectively inhabit the intestinal tract. Its composition is relatively stable; however, an imbalance can be precipitated by various factors and is known to be associated with various diseases. Humans are daily exposed to ionizing radiation from ambient and medical procedures, and gastrointestinal side effects are not rare. Methods: A systematic search of PubMed, EMBASE, and Cochrane Library databases was conducted. Primary outcomes were changes in composition, richness, and diversity of the gut microbiota after ionizing radiation exposure. Standard methodological procedures expected by Cochrane were used. Results: A total of 2929 nonduplicated records were identified, and based on the inclusion criteria, 11 studies were considered. Studies were heterogeneous, with differences in population and outcomes. Overall, we found evidence for an association between ionizing radiation exposure and dysbiosis: reduction in microbiota diversity and richness, increase in pathogenic bacteria abundance (Proteobacteria and Fusobacteria), and decrease in beneficial bacteria (Faecalibacterium and Bifidobacterium). Conclusions: This review highlights the importance of considering the influence of ionizing radiation exposure on gut microbiota, especially when considering the side effects of abdominal and pelvic radiotherapy. Better knowledge of these effects, with larger population studies, is needed.
- Sensação retardada de dor muscularPublication . Cervaens, Mariana; Barata, PedroSempre que é efectuado um exercício ou uma actividade intensiva inabitual, de forma excêntrica, o organismo reage nas seguintes 24 horas com sintomas desde aumento da sensibilidade até a uma dor severa e limitativa e, conforme a sua severidade, desaparece por completo após 10 dias. Esta sintomatologia caracteriza-se como Sensação Retardada de Dor Muscular (SRDM). Embora o seu mecanismo não seja conhecido, existem várias hipóteses, sendo o objectivo deste estudo rever os factores envolvidos neste processo de lesão, abordando, também, brevemente as alterações na função muscular e o seu tratamento. Whenever an eccentric exercise or an unusual physical activity is performed, the body reacts on the following 24 hours with symptoms that vary from an increase of sensibility to severe pain that usually disappears after a maximum period of 10 days. This is called Delayed Onset Muscle Soreness (DOMS). Although its mechanism is not yet fully known, several hypotheses are considered. The purpose of this paper is to review the factors involved in the injury process together with the changes in the muscular system and its treatment.
- Topical probiotics: the future of dermatology to improve the health of the skin microbiomePublication . Schutz, Francine; Barata, Pedro; Oliveira, Rita
- Physical and chemical stimuli-responsive drug delivery systems: targeted delivery and main routes of administrationPublication . Lopes, Joana R.; Santos, Gory; Barata, Pedro; Oliveira, Rita; Lopes, Carla MartinsIn the area of drug delivery, novel tools and technological approaches have captured the attention of researchers in order to improve the performance of conventional therapeutics and patient compliance to pharmacological therapy. Stimuli-responsive drug delivery systems (DDS) appear as a promising approach to control and target drug delivery. When these DDS are administered, the drug release is activated and then modulated through some action or external input and facilitated by the energy supplied externally. The stimuli responsible to activate the drug release can be classified into three types according to their nature or the type of energy applied: physical (e.g. magnetic field, electric field, ultrasound, temperature and osmotic pressure); chemical (e.g. pH, ionic strength and glucose); and biological (enzymes and endogenous receptors). The present review gives an overview of the most significant physical and chemical stimuliresponsive DDS and elucidates about their current and relevant applications in controlled and targeted drug delivery attending different routes of administration.
- Capítulo 6 - MicroencapsulaciónPublication . Lopes, Carla Martins; Barata, Pedro
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