Influence of phospholipid composition on cationic emulsions/DNA complexes: physicochemical properties, cytotoxicity, and transfection on Hep G2 cells

Michelle Fraga1,2, Fernanda Bruxel1, Valeska Lizzi Lagranha2,3, Helder Ferreira Teixeira1, Ursula Matte2,31Post Graduation Program in Pharmaceutical Sciences, Universidade Federal do Rio Grande do Sul, 2Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, 3Post Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, BrazilBackground: Cationic nanoemulsions have been recently considered as potential delivery systems for nucleic acids. This study reports the influence of phospholipids on the properties of cationic nanoemulsions/DNA plasmid complexes.Methods: Nanoemulsions composed of medium-chain triglycerides, stearylamine, egg lecithin or isolated phospholipids, ie, DSPC, DOPC, DSPE, or DOPE, glycerol, and water were prepared by spontaneous emulsification. Gene transfer to Hep G2 cells was analyzed using real-time polymerase chain reaction.Results: The procedure resulted in monodispersed nanoemulsions with a droplet size and zeta potential of approximately 250 nm and +50 mV, respectively. The complexation of cationic nanoemulsions with DNA plasmid, analyzed by agarose gel retardation assay, was complete when the complex was obtained at a charge ratio of ≥1.0. In these conditions, the complexes were protected from enzymatic degradation by DNase I. The cytotoxicity of the complexes in Hep G2 cells, evaluated by MTT assay, showed that an increasing number of complexes led to progressive toxicity. Higher amounts of reporter DNA were detected for the formulation obtained with the DSPC phospholipid. Complexes containing DSPC and DSPE phospholipids, which have high phase transition temperatures, were less toxic in comparison with the formulations obtained with lecithin, DOPC, and DOPE.Conclusion: The results show the effect of the DNA/nanoemulsion complexes composition on the toxicity and transfection results.Keywords: plasmids, cationic nanoemulsions, phospholipids, physicochemical characterization, gene transfer, stearylamin

Desenvolvendo contadores criativos: como o design thinking promove a valorização do profissional contábil?

By addressing innovation, creativity, and problem-solving in corporate contexts, Design Thinking has attracted the interest of both scholars and professionals. Despite this, this methodology has still been little disseminated among accounting professionals. Therefore, this study aimed to identify how the Design Thinking methodology can be used to promote the appreciation of the accounting professional. The study involved 521 students who attended the Accounting Planning discipline, offered in the seventh stage of the Accounting Sciences course at a federal university in southern Brazil. Using the survey as a technical procedure, the content analysis of the records of perceptions and ideas generated in Design Thinking workshops was conducted using Nvivo and Microsoft Excel. The students' perceptions regarding the application of the methodology showed that its use is conducive to creating innovative ideas and making them leave their comfort zone. Students reported being aware that they use creativity very little. Still, they are concerned about their development, as they understand that it adds professional and personal value and benefits the profession as a whole. The practical implication is the illustration of how this methodology can contribute to establishing a new professional image, and federal and state accounting councils can use it.Por abordar a inovação, criatividade e solução de problemas nos contextos corporativos, o Design Thinking tem despertado interesse tanto de acadêmicos, quanto de profissionais. Apesar disso, essa metodologia ainda tem sido pouco difundida entre os profissionais contábeis. Portanto, este estudo teve por objetivo identificar como a metodologia do Design Thinking pode ser utilizada para promover a valorização do profissional contábil. O estudo envolveu 521 discentes que cursaram a disciplina de Planejamento Contábil, ofertada na sétima etapa do curso de Ciências Contábeis de uma universidade federal do sul do Brasil. Utilizando o levantamento como procedimento técnico, realizou-se a análise de conteúdo dos registros das percepções e das ideias geradas em oficinas de Design Thinking, com uso do Nvivo e Microsoft Excel. As percepções dos estudantes, quanto à aplicação da metodologia, evidenciaram que sua utilização é propícia para a criação de ideias inovadoras, bem como fez com que eles saíssem da zona de conforto. Os estudantes registraram estar cientes de que utilizam muito pouco a criatividade, mas se preocupam com seu desenvolvimento, pois entendem que agrega valor profissional e pessoal, além de beneficiar a profissão como um todo. Tem-se como implicação prática a ilustração de como essa metodologia pode contribuir para o estabelecimento de uma nova imagem profissional, sendo possível que conselhos federais e estaduais de contabilidade a utilizem

Propagação vegetativa de uma espécie endêmica do bioma Pampa.

The definition of vegetative propagation methodologies is an alternative for the preservation of endangered native species with potential for economic exploitation, as Hesperozygis ringens. Thus, this study aims to verify the possibility of propagating this species through cutting, testing different substrates and types of cuttings, and comparing the propagation through cuttings obtained from atock plants in a greenhouse and directly in the field. Apical and non-apical cuttings, 6.0cm long, obtained from material from the field and greenhouse, were propagated in trays containing carbonized rice husk and a mixture of carbonized rice husk with coconut fiber powder (2:1, v/v) as substrates. Completely randomized blocks were used in a 2x2 factorial design, with four replicates of 10 cuttings. The plantlets production of H. ringens by cutting is feasible, since it presents a high rooting percentage even when propagules are collected in plants of populations in situ. However, when collected from plants in a greenhouse, the root system of plantlets presents a higher quality than that obtained in field, making possible the production and establishment of plantlets in greenhouses

Use of the dialysis bag method to evaluate the in vitro release of drugs from submicrometric carriers

A técnica da bolsa de diálise vem sendo usada para avaliar a liberação in vitro de fármacos a partir de carreadores submicrométricos, na sua forma original, ou através do método de diálise reversa. Neste contexto, o objetivo deste trabalho foi descrever os aspectos práticos envolvidos no processo da diálise e revisar os trabalhos descritos na literatura que empregaram estes métodos para avaliar o perfil de liberação de fármacos a partir de emulsões submicrométricas destinadas à via intravenosa. Para o método original, os resultados mostram uma liberação lenta de fármaco num longo período de análise, o que leva os autores a acreditar que o sistema apresenta características de liberação prolongada. Já o método da bolsa de diálise reversa conduz à obtenção de perfis de liberação que parecem refletir um pouco melhor as condições in vivo, quando são testadas emulsões para via intravenosa.The dialysis bag method has been employed to evaluate the in vitro release of drugs from submicrometric carriers, either through its conventional form or through the reverse dialysis approach. In this context, the purpose of this work was to present practical aspects involved in the dialysis process and to review studies described in the literature that employed such methods in order to evaluate the release of drugs from submicron emulsions intended to intravenous administration. With respect to the original method, the results showed a slow drug release within a long period of analysis, which makes the authors to believe that the systems present prolonged release features. On the other hand, the reverse dialysis method leads to release profiles that seem to better reflect the in vivo conditions, as far as intravenous emulsions are concerned.Colegio de Farmacéuticos de la Provincia de Buenos Aire

The use of Brazilian vegetable oils in nanoemulsions: an update on preparation and biological applications

Vegetable oils present important pharmacological properties, which gained ground in the pharmaceutical field. Its encapsulation in nanoemulsions is considered a promising strategy to facilitate the applicability of these natural compounds and to potentiate the actions. These formulations offer several advantages for topical and systemic delivery of cosmetic and pharmaceutical agents including controlled droplet size, protection of the vegetable oil to photo, thermal and volatilization instability and ability to dissolve and stabilize lipophilic drugs. For these reasons, the aim of this review is to report on some characteristics, preparation methods, applications and especially analyze recent research available in the literature concerning the use of vegetable oils with therapeutic characteristics as lipid core in nanoemulsions, specially from Brazilian flora, such as babassu (Orbignya oleifera), aroeira (Schinus molle L.), andiroba (Carapa guaianiensis), casca-de-anta (Drimys brasiliensis Miers), sucupira (Pterodon emarginatus Vogel) and carqueja doce (Stenachaenium megapotamicum) oils

Nanoemulsões como sistemas de liberação parenteral de fármacos

Lipid nanoemulsions have recently been proposed as parenteral delivery systems for poorly-soluble drugs. These systems consist of nanoscale oil/water dispersions stabilized by an appropriate surfactant system in which the drug is incorporated into the oil core and/or adsorbed at the interface. This article reviews technological aspects of such nanosystems, including their composition, preparation methods, and physicochemical properties. From this review, it was possible to identify five groups of nanoemulsions based on their composition. Biopharmaceutical aspects of formulations containing some commercially available drugs (diazepam, propofol, dexamethasone, etomidate, flurbiprofen and prostaglandin E1) were then discussed

Por que preservar os campos do extremo sul do Brasil?

In Brazil, grassland ecosystems of the Pampa are restricted to Rio Grande do Sul State (RS) and constitute the largest temperate natural grassland in the world. There are no recent data to indicate how much of these fields was lost in the state, but excursions made in recent years have pointed to a high conversion of native fields into crops. This situation has alerted to the intensification of biodiversity loss and the biological impoverishment of these fields. In view of the above, this study characterizes plant diversity in fields of the southern and western portion of RS. The study was based on publications of recent years that indicate the problems that effectively threaten this diversity. Pampa fields are natural and have a great diversity, constituting a considerable genetic heritage, ensuring the provision of ecosystem services to human populations. The few bioprospecting studies on species from these fields suggest that much remains to be discovered and that actions need to be taken to inhibit field destruction. These fields have never been treated as priority areas for conservation, but it is our commitment to reverse this transformation and destruction.No Brasil, os ecossistemas campestres do Pampa estão restritos ao Rio Grande do Sul (RS) e constituem a maior área de pastagem natural de clima temperado do mundo. Não existem dados recentes que indiquem o quanto se perdeu desses campos no RS, mas excursões realizadas nos últimos anos têm possibilitado a percepção de que é alta a conversão dessas áreas nativas em lavouras. Tal situação tem alertado para a intensificação da perda da diversidade e do empobrecimento biológico desses campos. Diante disso, o estudo objetivou caracterizar a diversidade vegetal dos campos da metade sul e oeste do RS, baseado em publicações dos últimos anos. Os campos pampeanos são naturais, com grande biodiversidade, constituindo um considerável patrimônio genético, garantindo a prestação de serviços ecossistêmicos para as populações humanas. Os poucos estudos de bioprospecção com espécies desses campos sugerem que muito ainda pode ser descoberto e que é preciso implantar ações para inibir a destruição dos mesmos. Esses campos nunca foram tratados como áreas prioritárias para a conservação, no entanto, é nosso compromisso reverter esse quadro de transformação e destruição

Spectrophotometric determination of coumarins incorporated into nanoemulsions containing pterocaulon balansae extract

This article reports the validation of a spectrophotometric method to estimate coumarins incorporated into nanoemulsions containing Pterocaulon balansae Chodat extract. The quantification was based on the assay of esculin at 327 nm, which presents the same substitution pattern of coumarins isolated from Pterocaulon species. Linear response (R2 > 0.995) was observed over the range of 5.0 to 25.0 μg/mL. The relative standard deviation values for the intra- and inter-days precision were lower than 3.0 %. The recovery ranged from 93.3 % to 104.1 %. The association efficiency was estimated after the determination of free coumarins in the water phase of nanoemulsions obtained after separation through ultrafiltration/centrifugation devices. The coumarins association was approximately 92 %.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Bacterial and Archaeal Communities Change With Intensity of Vegetation Coverage in Arenized Soils From the Pampa Biome

Arenization occurs in regions that present sandy soils with normal rainfall levels. Predatory use of environmental sources, the dissolution of arenitic rocks and reworking of non-consolidated surface sands intensify this degradation scenario. Thus, this work aimed to evaluate the impact of the arenization process in the Brazilian Pampa Biome and how this phenomenon affects the soil microbial and plant communities. For this purpose, three arenized areas in Southern Brazil (Pampa Biome) were selected and, in each one, three sampling points were studied: arenized (ARA), arenized to grassland transition (AGT), and grassland (GRA) areas. In the three sampling points, soils presented low levels of nutrients, organic matter, mud and pH acidic in all regions but, the presence of vegetation coverage in AGT and GRA areas preserved the topsoil structure. Our study related ARA with bacterial families Alcaligenaceae, Pseudomonadaceae, and Xanthomonadaceae. AGT with bacterial families Bacillaceae and Burkholderiaceae, and plant species Melinis repens (Willd.) Zizka and Paspalum stellatum Humb. and Bonpl. ex Flüggé, and GRA with bacterial families Koribacteraceae, Hyphomicrobiaceae, and Chthoniobacteraceae, and plant species Croton subpannosus Müll.Arg. ex Griseb., Piptochaetium montevidense (Spreng.) Parodi and Elyonurus sp. The three studied areas (as well as sampling points) present soils extremely poor in nutrients with sandy texture, and the bacterial and plant composition well known to be resistant to environmental stresses were dominant. The vulnerability of these areas causes a degradation scenario, which is worsened by agricultural activities. However, in general, this phenomenon is a natural process that occurs mainly due to soil characteristics (poor soils) and climatic variations