Abstract Gels containing juca seed galactomannan (JSG) were evaluated for their potential to prevent the progression of dentin erosive wear in an in vitro study with four experimental groups (n = 9). The treatments included distilled water (DW), 0.05% stannous fluoride (121 ppm F), and 0.5% or 1% JSG. The specimens underwent a cycle (3 times/day) consisting of immersion in 1% citric acid (5 minutes), treatment (5 minutes), and artificial saliva exposure (2 hours/overnight) for 5 days. Surface changes were assessed using mechanical profilometry (wear), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The data were analyzed using ANOVA followed by Tukey's post-test (p < 0.05). The negative control group exhibited the highest wear (6.0 µm ± 3.5), significantly differing from the group treated with 0.05% stannous fluoride gel (p = 0.007), which showed less dentin loss. The groups treated with 0.5% and 1% JSG showed results similar to the negative control (p = 0.661; p = 0.212, respectively) and the stannous fluoride group (p = 0.103; p = 0.379, respectively). In the SEM images, the specimen treated with stannous fluoride showed obliterated tubules, while the JSG gels formed crystals on the dentin surface, as confirmed by the presence of oxygen and calcium in the EDS analysis. Although the JSG gels showed similar results to the stannous fluoride, did not exhibit superior efficacy at the tested concentrations.

Resumo Géis contendo galactomanana da semente de jucá (GSJ) foram avaliados quanto ao seu potencial na prevenção da progressão do desgaste erosivo dentinário em um estudo in vitro com quatro grupos experimentais (n = 9). Os tratamentos incluíram água destilada (AD), 0,05% de fluoreto de estanho (121 ppm F) e 0,5% ou 1% de GSJ. Os espécimes passaram por um ciclo (3 vezes ao dia) que consistia em imersão em ácido cítrico 1% (5 minutos), tratamento (5 minutos) e exposição a saliva artificial (2 horas/durante a noite) por 5 dias. As alterações de superfície foram avaliadas utilizando perfilometria mecânica (desgaste), microscopia eletrônica de varredura (MEV) e espectroscopia de raios-X por dispersão de energia (EDS). Os dados foram analisados por ANOVA, seguida do pós-teste de Tukey (p < 0,05). O grupo controle negativo apresentou o maior desgaste (6,0 µm ± 3,5), diferindo significativamente do grupo tratado com gel de fluoreto de estanho a 0,05% (p = 0,007), que apresentou menor perda de dentina. Os grupos tratados com 0,5% e 1% de GSJ apresentaram resultados semelhantes ao grupo controle negativo (p = 0,661; p = 0,212, respectivamente) e ao grupo de fluoreto de estanho (p = 0,103; p = 0,379, respectivamente). Nas imagens de MEV, o espécime tratado com fluoreto de estanho mostrou túbulos obliterados, enquanto os géis GSJ formaram cristais na superfície da dentina, como confirmado pela presença de oxigênio e cálcio na análise de EDS. Embora os géis GSJ tenham apresentado resultados semelhantes ao fluoreto de estanho, eles não demonstraram eficácia superior nas concentrações testadas.

Abstract This article aims to report the preparation and optimized formulation of Ctn[15-34], a designed anti-infective peptide, with poly(lactic acid-co-glycolic acid), PLGA, nanoparticles. Ctn[15-34] is a short peptide derived from crotalicidin, a cathelicidin-related antimicrobial peptide from the venom of the South American rattlesnake (Crotalus durissus terrificus), that has arisen as a promising antifungal and microbicide agent. The PLGA nanoparticles were prepared and loaded with carboxyfluorescein (CF)-Ctn[15-34] using the double emulsion/solvent evaporation method. After a preformulation study, which tested different formulation parameters, Poly (vinyl alcohol) 87-89% hydrolyzed and sonication with Sonifier® were choosen to prepare unloaded PLGA nanoparticles by that method, resulting in smaller particle size and Polydispersity Index (PDI) values and higher zeta potential values of nanoparticles. This better condition was used to prepare CF-Ctn[15-34]-loaded PLGA nanoparticles, resulting in homogeneous and spherical nanoparticles, with an average size of 213.2 ± 2.00 nm, PDI of 0.044 ± 0.04 and zeta potential of -16.03 ± 1.20 mV. An excellent encapsulation efficiency was obtained, corresponding to 93.3 ± 0.10 %. The drug-release profile showed a rapid initial release of the peptide, approximately 27 % in the first 24 hours, followed by a sustained release for at least 16 days. Another relevant aspect in the peptide formulation is that the CF-Ctn[15-34]-loaded nanoparticles potentiated the antifungal effect against the opportunistic pathogenic yeast Cryptococcus neoformans compared with the free, in solution Ctn[15-34], in equivalent volume dosage. A preparation method of CF-Ctn[15-34]-loaded PLGA nanoparticles was established and validated, representing a successful approach to deliver CF-Ctn[15-34] for pharmaceutical applications.

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.