Nanotechnology applied to medical biofilms control

Nanoscience and Nanotechnology (N&N) are new approaches to research phenomena at atomic, molecular and macromolecular scales, where properties differ significantly from those at a larger scale. This new approach can be applied to microbial biofilms, which are formed when bacterial and/or yeast cells adhere to abiotic and biotic surfaces. It is well known that microorganisms in biofilms have a different behaviour from their planktonic counterparts, demonstrating a general recalcitrance to medical therapy. Therefore, biofilm-associated infections on indwelling medical devices, such as catheters and prostheses, may persist even after suspension of antibiotic therapy and hence may require the removal of the device. In order to reduce patient`s morbidity and mortality, as well as high economical costs associated to medical biofilms, several attempts have been made to develop novel mechanisms of biofilm prevention and/or elimination. In this mini-review, the current knowledge on the features of biofilm formation and their relevance to medical device-associated infections are enclosed, as well as the new anti-biofilm approaches based on nanotechnology.The support by Portuguese Foundation for Science and Technology through the grants SFRH/BPD/47693/2008 and SFRH/BPD/20987/2004 is gratefully acknowledged

NaOCl effect on biofilm produced by Staphylococcus aureus isolated from the milking environment and mastitis infected cows

Biofilms constitute a physical barrier, protecting the encased bacteria from detergents and sanitizers. The objective of this work was to analyze the effectiveness of sodium hypochlorite (NaOCl) against strains of Staphylococcus aureus isolated from raw milk of cows with subclinical mastitis and Staphylococcus aureus isolated from the milking environment (blowers and milk conducting tubes). The results revealed that, in the presence of NaOCl (150ppm), the number of adhered cells of the twelve S. aureus strains was significantly reduced. When the same strains were evaluated in biofilm condition, different results were obtained. It was found that, after a contact period of five minutes with NaOCl (150ppm), four strains (two strains from milk , one from the blowers and one from a conductive rubber) were still able to grow. Although with the increasing contact time between the bacteria and the NaOCl (150ppm), no growth was detected for any of the strains. Concerning the efficiency of NaOCl on total biofilm biomass formation by each S. aureus strain, a decrease was observed when these strains were in contact with 150 ppm NaOCl for a total period of 10 minutes. This study highlights the importance of a correct sanitation protocol of all the milk processing units which can indeed significantly reduce the presence of microorganisms, leading to a decrease of cow´s mastitis and milk contamination.This study was supported by Portuguese Foundation for Science and Technology (FCT) through the grant SFRH/BPD/20987/2004 attributed to Cláudia Botelho and thanks to FAPESP (Fundação de Amparo a Pesquisa do Estado de São Paulo) for the scholarship attributed to Poliana de C. Melo

Exploiting the potential of bioactive molecules extracted by ultrasounds from avocado peelsfood and nutraceutical applications

Natural bioactive compounds from food waste have fomented interest in food and pharmaceutical industries for the past decade. In this work, it purposed the recovery of bioactive avocado peel extract using an environmentally friendly technique: the ultrasound assisted extraction. The response surface methodology was applied in order to optimize the conditions of the extraction, ethanol-water mixtures and time. The optimized extracts (ethanol 38.46%, 44.06 min, and 50 °C) were chemically characterized by HPLC-ESI-MS and FTIR. Its antioxidant ability, as well as, its effect on cell metabolic activity of normal (L929) and cancer (Caco-2, A549 and HeLa) cell lines were assessed. Aqueous ethanol extracts presented a high content in bioactive compounds with high antioxidant potential. The most representative class of the phenolic compounds found in the avocado peel extract were phenolic acids, such as hydroxybenzoic and hydroxycinnamic acids. Another important chemical group detected were the flavonoids, such as flavanols, flavanonols, flavones, flavanones and chalcone, phenylethanoids and lignans. In terms of its influence on the metabolic activity of normal and cancer cell lines, the extract does not significantly affect normal cells. On the other hand, it can negatively affect cancer cells, particularly HeLa cells. These results clearly demonstrated that ultrasound is a sustainable extraction technique, resulting in extracts with low toxicity in normal cells and with potential application in food, pharmaceutical or nutraceutical sectors.The authors acknowledge the financial support received from “Xunta de Galicia” (GRC ED431C 2017/62-GRC, and Project ED431F 2020/03). These projects are partially funded by the FEDER Program of the European Union (“Unha maneira de facer Europa”). This research was also funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. Beatriz Gullón would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for her postdoctoral grant (Reference RYC2018-026177-I).info:eu-repo/semantics/publishedVersio

Novel liposomes for Alzheimers disease treatment

This work was supported by the strategic programme UID/BIA/04050/2019, funded by national funds through the FCT IP, and project FUN2CYT: Harnessing the potential for biomedical applications of pleiotropic cytokines LIF and oncostatin M (PTDC/BTM-MAT/30568/2017, POCI-01-0145-FEDER-030568) supported by POCI through FEDER and FCT IP.info:eu-repo/semantics/publishedVersio

Microfluidics for controlled self-assembly of cubosome nanoparticles of tunable size

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Chicken feather keratin peptides for the control of keratinocyte migration

FAO estimates that in 2030 the poultry meat production could reach 120 million tons, which is a challenge in terms of waste management. Feathers are mainly composed of keratin, an important biomaterial. Using feathers as a source of keratin will minimize the waste generated, while contributing to supply an important material for several industries, such as pharmaceutical and biomedical. The peptides were extracted from the feathers by microbial degradation. In this study, we evaluated the peptides effect on keratinocyte metabolic activity and migration. The influence of these peptides on non-activated and activated macrophages was also assessed. It was demonstrated that depending on the keratin peptide fraction in contact with keratinocytes, it is possible to modulate the migration rate of the keratinocytes. Peptide fraction with low molecular weight increases migration, while peptides with a high range of molecular sizes decreases it. Some peptide fractions induce the secretion of TNF- in non-activated macrophages and not on activated macrophages, demonstrating that these peptides should only be placed in contact with cells, in the context of an ongoing inflammatory process. This work is a step forward on the understanding of keratin peptides influence on keratinocytes and immune cells system cells, macrophages.This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. It was also was financed by the Portuguese Mass Spectrometry Network, integrated in the National Roadmap of Research Infrastructures of Strategic Relevance (ROTEIRO/0028/2013; LISBOA-01-0145-FEDER-022125) and the MAC 2014-2020-MAC/1.1b/042-INTERREG V A España-Portugal, “BIOTRANSFER 2: Transferencia de la investigación biotecnológica orientada a rentabilidad empresarial y movilización de flujos de negocio 2”.info:eu-repo/semantics/publishedVersio

Contributo para a inventariação da biodiversidade marinha da ilha de Santa Maria

XIV Expedição Científica do Departamento de Biologia - Santa Maria 2009.Na XIV Expedição Cientifica à ilha de Santa Maria 2009, organizada pelo Departamento de Biologia da Universidade dos Açores, foram realizados vários trabalhos em diversos locais do litoral da ilha, tendo como objectivo o registo, recolha e identificação de espécies marinhas, tendo sido feita amostragem de fauna e flora intertidal e subtidal (em mergulho com escafandro autónomo). Em cada um dos locais de amostragem procedeu-se a identificação dos exemplares in loco e quando esta não era possível, os indivíduos foram colectados para posterior identificação em laboratório. Em paralelo, colectaram-se algas e crustáceos decápodes para análise genética (sequenciação de DNA; COI). Foram ainda efectuados dois arrastos para recolha de plâncton. Toda a informação obtida irá ser incluída na base de dados Atlantis. Os trabalhos efectuados inserem-se no âmbito de vários projectos em curso no Departamento de Biologia da UAç (e.g. LusoMarBol, Inspect). A inventariação de espécies resultou no acréscimo de 18 registos à lista de espécies costeiras e marinhas anteriormente referenciadas para Santa Maria, contribuindo deste modo para um melhor conhecimento da biodiversidade costeira e marinha da ilha de Santa Maria

Effective cytocompatible nanovectors based on serine-derived gemini surfactants and monoolein for small interfering RNA delivery

Supplementary data to this article can be found online athttps://doi.org/10.1016/j.jcis.2020.09.077.Non-viral gene therapy based on gene silencing with small interfering RNA (siRNA) has attracted great interest over recent years. Among various types of cationic complexation agents, amino acid-based surfactants have been recently explored for nucleic acid delivery due to their low toxicity and high biocompatibility. Monoolein (MO), in turn, has been used as helper lipid in liposomal systems due to its ability to form inverted nonbilayer structures that enhance fusogenicity, thus contributing to higher transfection efficiency. In this work, we focused on the development of nanovectors for siRNA delivery based on three gemini amino acid-based surfactants derived from serine (12Ser)2N12, amine derivative; (12Ser)2COO12, ester derivative; and (12Ser)2CON12, amide derivative individually combined with MO as helper lipid. The inclusion of MO in the cationic surfactant system influences the morphology and size of the mixed aggregates. Furthermore, the gemini surfactant:MO systems showed the ability to efficiently complex siRNA, forming stable lipoplexes, in some cases clearly depending on the MO content, without inducing significant levels of cytotoxicity. High levels of gene silencing were achieved in comparison with a commercially available standard indicating that these gemini:MO systems are promising candidates as lipofection vectors for RNA interference (RNAi)-based therapies.The authors acknowledge Fundação para a Ciência e a Tecnolo-gia (FCT) for financial support through projects UIDB/00081/2020 and UIDB/50006/2020. This work was supported by the‘‘Contrato-Programa” UIDB/04050/2020 funded by national fundsthrough the FCT I.P. Dr. Marisa Passos is gratefully acknowledged for help with the statistical analysis of cytotoxicity data. Fundingby the CCDR-N/NORTE2020/Portugal2020 through project DESign-BIOtechHealth (ref. Norte-01-0145-FEDER-000024) is also acknowledged. I. S. Oliveira and S.G. Silva also acknowledge finan-cial support from FCT through PhD grant SFRH/BD/108629/2015 and Individual Call to Scientific Employment Stimulus - CEEC Indi-vidual grant CEECIND/01932/2017, respectivelyinfo:eu-repo/semantics/publishedVersio

The OBAA Standard for Developing Repositories of Learning Objects: the Case of Ocean Literacy in Azores

This paper describes the existing web resources of learning objects to promote ocean literacy. The several projects and sites are explored, and the shortcomings revealed. The limitations identified include insufficient metadata about registered learning objects and lack of support for intelligent applications. As solution, we promote the seaThings project that relies on a multi-disciplinary approach to promote literacy in the marine environment by implementing a specific Learning Objects repositories (LOR) and a federation of repositories (FED), supported by a OBAA, a versatile and innovative standard that will provide the necessary support for intelligent applications for education purposes, to be used in schools and other educational institutions.info:eu-repo/semantics/publishedVersio

Cytotoxicity assessment of endodontic sealers: metabolic activity, morphology and chromosomal alterations

Introduction: Endodontic treatment aims to eliminate infection of the root canals and fill the dental pulp space, being, the obturation of root canals an important step. The study of the toxicity/biocompatibility of the sealers used to fill the root canals is crucial since they are applied into direct contact with periradicular tissues.There are several types of sealers, categorized according to their main chemical constituents. The aim of this study was to evaluate the cytotoxicity of three root canal sealers, AH Plus, Bio MTA+ and Bio C, on immortalized human gingival fibroblasts. Methods: To study the cytotoxicity of the sealers we performed a Methyltetrazolium (MTT) assay, a study of cell's morphology and a cytogenetic study. Cells were placed in contact with material-conditioned media, for 24 h, at three different concentrations (1, 10 and 100 mg/ml) for the MTT assay. Cell morphology and cytogenetic studies were performed at 100 mg/ml. Cells in normal culture medium were analyzed as control group. Results: MTT assay revealed a cytotoxic effect of Bio MTA+ and Bio C with a growing decrease of metabolic activity with increasing compound concentration, reaching 50% with 100 mg/ml. Regarding the cells morphology, Bio C was the compound that showed a more drastic effect, with a decrease in cell confluence and several morphological changes. AH Plus and Bio MTA+ did not seem to affect the cell confluence, however morphology changes were observed, as compromised cell membranes and loss of cell content. Cytogenetic study was thus far only performed with AH Plus. Since there was a severe decrease of mitotic index after treatment, it was not yet possible to obtain sufficient metaphases, even after several cytogenetic harvesting procedures, but, so far, no relevant structural or numerical changes were observed. Discussion: This preliminary study allowed us to verify that these root canal sealers exhibit some cytotoxicity, depending on the concentration used. Although more studies are still needed, this work could be important to both, help in the selection of the most appropriate compounds for clinical practice and to determine the maximum recommended amounts of each sealer.info:eu-repo/semantics/publishedVersio