ABSTRACT Titanate nanotubes (TiNTs) with the chemical composition Na2Ti3O7.nH2O (NaTiNT) were obtained through a hydrothermal method in highly alkaline medium. Protonated titanates nanotubes (H-TiNTs), with the composition H2Ti3O7.nH2O, were prepared by ion exchange reaction through a suspension of Na2Ti3OγnH2O nanotubes in HCl medium, promoting the exchange of Na+ ions by H+. Both Na2Ti3O7.nH2O and H2Ti3O7.nH2O products, as well the TiO2 used as raw material for the nanotubes processing, were used as starting material for the solar cells photoelectrodes sensitized using mesoporphyrin extracted from a precursor of cashew nut shell. Exposing the NaTiNT sample to solar radiation of 1258 W/m2, a short-circuit current density (ISC) of 13 µA/cm2 and an open-circuit voltage (VOC) of 370 mV were registered and, a current density of 7.6 µA/cm2 and a voltage of 256 mV for the prototype cell based on H-TiNTs. A current density of 1.1 µA/cm2 and an open-circuit voltage of 1.6 mV were obtained for the cell using TiO2 as electrode.

Abstract A growing global trend for maximum use of natural resources through new processes and products has enhanced studies and exploration of renewable natural materials. In this study, cardanol, a component of the cashew nut shell liquid (CNSL), was used as a building block for the development of a thermosetting matrix, which was reinforced by raw and modified sponge gourd fibers (Luffa cylindrica). DSC and TG results showed that among biocomposites, the one reinforced by sponge gourd fibers treated with NaOH 10 wt% (BF10) had the highest thermal stability, besides the best performance in the Tensile testing, showing good incorporation, dispersion, and adhesion to polymer matrix, observed by SEM. After 80 days of simulated soil experiments, it has been discovered that the presence of treated fiber allowed better biodegradability behavior to biocomposites. The biobased thermoset plastic and biocomposites showed a good potential to several applications, such as manufacturing of articles for furniture and automotive industries, especially BF10.

SUMMARY Nanotechnology can be a valuable ally in the treatment of infections. Silver nanoparticles (AgNPs) are structures that have antimicrobial activity. The aim of this study was to produce AgNPs by green methods, characterize these structures, and assess their antimicrobial activity against Escherichia coli associated with the antibiotic ciprofloxacin. AgNPs were characterized by spectroscopic and microscopic techniques. Antimicrobial activity was evaluated by the disk diffusion method against 10 strains of E. coli. The synthesized AgNPs showed a spherical shape and a size of 85.07 ± 12.86 nm (mean ± SD). AgNPs increased the activity of ciprofloxacin by 40% and may represent a new therapeutic option for the treatment of bacterial infections.

Abstract Pluronics® molecules self-assemble in aqueous solution providing a core/shell architecture that improves the solubility of hydrophobic drugs. Binary mixtures of Pluronics® have been studied as drug nanocarriers in order to combine their advantages, like high colloidal stability, small particle size and good solubilisation capacity (Scp). In this work we studied Pluronics® binary mixture, P123 and F127, as nanocarriers of the hydrophobic drug griseofulvin. P123 (E21P67E21) shows a relative good Scp, whereas F127 (E98P67E98) shows a good colloidal stability. According to data, these binary mixtures form stables nano-sized comicelles in aqueous solution. The Scp of the P123/F127 systems at 25 and 37 °C was monitored by UV/Visible spectroscopy, showing good results at both temperatures, as would be expected, since P123/F127 have similar length hydrophobic block. Hydrophobic-dependence and temperature-responsive of the systems were evaluated by CMC, particle size and colloidal stability. Hence, stables P123/F127 comicelles may have potencial as hydrophobic drug delivery.

Nanopartículas de Prata (AgNPs) são estruturas metálicas em escala nanométrica. AgNPs apresentam atividades antimicrobianas contra fungos e bactérias; no entanto, a síntese de AgNPs pode gerar resíduos tóxicos e devido a isso novas rotas utilizando compostos atóxicos têm sido buscadas. O objetivo desse estudo foi sintetizar AgNPs utilizando a ribose como agente redutor e dodecil sulfato de sódio (SDS) como estabilizante e avaliar a atividade antifúngica dessas partículas contra C. albicans e C. tropicalis. Foram sintetizadas nanopartículas estáveis com 12,5 ± 0,2 nm (média ± DP) que apresentaram elevada atividade contra Candida spp. e podem representar boa alternativa no tratamento de infecções fúngicas.

Silver nanoparticles (AgNPs) are metal structures at the nanoscale. AgNPs have exhibited antimicrobial activities against fungi and bacteria; however synthesis of AgNPs can generate toxic waste during the reaction process. Accordingly, new routes using non-toxic compounds have been researched. The proposal of the present study was to synthesize AgNPs using ribose as a reducing agent and sodium dodecyl sulfate (SDS) as a stabilizer. The antifungal activity of these particles against C. albicans and C. tropicalis was also evaluated. Stable nanoparticles 12.5 ± 4.9 nm (mean ± SD) in size were obtained, which showed high activity against Candida spp. and could represent an alternative for fungal infection treatment.