Gene therapy is a promising tool for the treatment of ocular diseases. Nevertheless, there are some import limitations, especially related to the ocular route and the characteristics of nucleic acids that must be overcome to ensure the success of the therapy. In this context, nanotechnology-based carriers such as nanoemulsions, nanoparticles, dendrimers and liposomes have risen as a promising vehicle for the protection of genetic material for vectoring the target cells. The success of such approach is closely related to the judicious selection of the biomaterial, where chemical structure and intermolecular interactions play a major role. So, this manuscript reviews some of the most important biomaterials, lipid and polymeric origin, employed in the manufacture of nanotechnologic carriers for ocular gene therapy involving interfering RNA (siRNA), antisense oligonucleotide (AS-ON) and plasmid DNA (pDNA).

AbstractDepending on the method of extraction, plant extracts can contain an enormous variety of active molecules, such as phenolic compounds, essential oils, alkaloids, among others. In many cases, from a pharmacological point of view, it is interesting to work with crude extract or fractions instead of a single isolated compound. This could be due to multi-targeting effect of the extract, lack of knowledge of the active compounds, synergistic effect of the extract compounds, among others. In any case, in order to achieve a final product some issues must be overcome, including poor stability, solvent toxicity, and low solubility of the bioactive compound. Recently many nanotechnology-based strategies have been proposed as an alternative to solve these problems, especially liposomes, nanoemulsions and nanoparticles. In this sense, the present work aims to review the main nanotechnological approaches used for association of different plant extracts and the main achievements from using these technologies.

Nanoemulsions composed of a medium-chain triglyceride oil core stabilized by rapeseed or sunflower lecithins were prepared by spontaneous emulsification and high-pressure homogenization. These nanoemulsions are compared with formulations stabilized by egg lecithin. Nanoemulsions obtained by high-pressure homogenization display larger droplet size (230 to 440 nm) compared with those obtained by spontaneous emulsification (190 to 310 nm). The zeta potentials of the emulsions were negative and below -25 mV. Zeta potential inversion occurred between pH 3.0 and 4.0. The results demonstrate the feasibility of preparing lipid emulsions comprising rapeseed or sunflower lecithins by spontaneous emulsification and high-pressure homogenization.

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.

This study describes the validation of a spectrophotometric method to estimate oligonucleotides association with cationic nanoemulsions. Phosphodiester and phosphorothioate oligonucleotides targeting Plasmodium falciparum topoisomerase II were analyzed at 262 nm. Linear response (r > 0.998) was observed from 0.4 to 1.0 nmol/mL, the relative standard deviation values for the intra- and inter-days precision were lower than 2.6% and the recovery ranged from 98.8 to 103.6% for both oligonucleotides. The association efficiency was estimated based on an ultrafiltration/centrifugation method. Oligonucleotides recovery through 30 kDa-membranes was higher than 92%. The extent of oligonucleotides association (42 to 98%) varied with the composition of nanoemulsions

Genistein:β-cyclodextrin complexes with high drug loading (19.22%) were prepared by freeze-drying and characterized by differential scanning calorimetry and hydrogen nuclear magnetic resonance spectroscopy. The spatial configuration of the complex was proposed by means of 2D-NOESY experiment combined with molecular modeling. According to the results obtained, the interaction of genistein with β -cyclodextrin in a 1:1 complex is supposed to occur mainly through the insertion of the guest A-ring in cyclodextrin cavity, without rule out the possibility of inclusion through the B-ring, as previously reported in the literature.

Este artigo tem por tema a questão da legitimidade democrática sublinhando, para tanto, os limites da democracia representativa e as potencialidades represadas dentro do espectro político atual brasileiro da ação individual e coletiva, suplantando o viés quantitativo que predomina nas análises sobre o processo democrático no Brasil. Para além das variáveis tradicionalmente assentadas na tríade voto, partidos políticos e eleições, o artigo procura demonstrar que a democracia eleitoral brasileira ainda não consolidou uma cultura política democrática, na medida em que vem solidificando um plano de diferenciação entre representantes e representados, decorrente de mandatos cada vez mais imperativos e menos afeitos ao controle e à participação dos representados. Pesquisas quantitativas, fontes primárias, secundárias e a análise de movimentos sociais recentes no cenário nacional permitiram construir a hipótese aqui trabalhada de que o processo eleitoral, por si mesmo, não responde pela construção e consolidação de uma democracia plural e participativa.

This paper has for theme the subject of the democratic legitimacy underlining, for such, the limits of representative democracy and the potentialities dammed inside of current political Brazilian spectrum of individual and collective action, supplanting the quantitative bias that prevails in the analyses on the democratic process in Brazil. Beyond the variables traditionally seated in the triad vote, political parties and elections, this paper tries to demonstrate that the Brazilian electoral democracy still didn't consolidate a democratic political culture, in the measure in that it is solidifying a differentiation plane between representatives and represented, due to mandates more and more imperatives and less bound to the control and participation of those represented. Quantitative researches, primary sources, secondary sources and the analysis of recent social movements in the national scene allowed the building of the hypothesis worked here that the electoral process, for itself, doesn't answer for the construction and consolidation of a plural and participative democracy.

Le thème abordé dans cet article est celui de la question de la légitimité démocratique. Pour ce faire, les limites de la démocratie représentative ainsi que les potentialités retenues dans le spectre politique actuel brésilien d'une action individuelle et collective ont été mises en évidence, allant au-delà de l'aspect quantitatif prédominant dans les analyses du processus démocratique au Brésil. Pour dépasser les variables traditionnellement établies sur la triade vote, partis politiques et élections, nous essayons de montrer que la démocratie électorale brésilienne n'a pas encore réussi à consolider une culture politique démocratique, dans la mesure où elle renforce un plan de différentiation entre représentants et représentés, dû à des mandats de plus en plus impératifs et de moins en moins habitués au contrôle et à la participation des représentés. Des recherches quantitatives, des sources primaires, secondaires et l'analyse de mouvements sociaux récents sur la scène nationale ont permis de construire l'hypothèse selon laquelle le processus électoral, en soi, n'a aucun répondant pour la construction et la consolidation d'une démocratie plurielle et participative.

This paper describes the adsorption of an oligothymidylate (pdT16) on nanoemulsions obtained by spontaneous emulsification procedures. Formulations were composed by medium chain triglycerides, egg lecithin, glycerol, water (NE) and stearylamine (NE SA). After optimization of operating conditions, the mean droplet size was smaller than 255 nm. Adsorption isotherms showed a higher amount of pdT16 adsorbed on cationic NE SA (60 mg/g) compared to NE (20 mg/g). pdT16 adsorption was also evidenced by the inversion of the zeta-potential of NE SA (from +50 to -30 mV) and the morphology of oil droplets examined through transmission electron microscopy. The overall results showed the role of electrostatic interactions on the adsorption of pdT16 on the oil/water interface of nanoemulsions.