MOF-Based Polymeric Nanocomposite Films as Potential Materials for Drug Delivery Devices in Ocular Therapeutics.

Novel MOF-based polymer nanocomposite films were successfully prepared using Zr-based UiO-67 as a metal-organic framework (MOF) and polyurethane (PU) as a polymeric matrix. Synchrotron X-ray powder diffraction (SXRPD) analysis confirms the improved stability of the UiO-67 embedded nanocrystals, and scanning electron microscopy images confirm their homogeneous distribution (average crystal size ∼100-200 nm) within the 50 µm thick film. Accessibility to the inner porous structure of the embedded MOFs was completely suppressed for N2 at cryogenic temperatures. However, ethylene adsorption measurements at 25 °C confirm that at least 45% of the MOF crystals are fully accessible for gas-phase adsorption of nonpolar molecules. Although this partial blockage limits the adsorption performance of the embedded MOFs for ocular drugs (e.g., brimonidine tartrate) compared to the pure MOF, an almost 60-fold improvement in the adsorption capacity was observed for the PU matrix after incorporation of the UiO-67 nanocrystals. The UiO-67@PU nanocomposite exhibits a prolonged release of brimonidine (up to 14 days were quantified). Finally, the combined use of SXRPD, thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) analyses confirmed the presence of the drug in the nanocomposite film, the stability of the MOF framework and the drug upon loading, and the presence of brimonidine in an amorphous phase once adsorbed. These results open the gate toward the application of these polymeric nanocomposite films for drug delivery in ocular therapeutics, either as a component of a contact lens, in the composition of lacrimal stoppers (e.g., punctal plugs), or in subtenon inserts.

Benzocaína e eugenol como anestésicos para o quinguio (Carassius auratus) / Benzocaine and eugenol as anesthetics for golden fish (Carassius auratus)

Avaliaram-se os tempos de indução e recuperação de quinguios (Carassius auratus) expostos a dois anestésicos, eugenol e benzocaína. Foram utilizados 128 juvenis com peso médio de 2,07±0,53g e comprimento total médio de 5,51±0,56cm. A benzocaína mostrou ser mais eficiente do que o eugenol em relação ao tempo, tanto para indução ao coma quanto para a recuperação à fuga e também no que diz respeito à sobrevivência. As doses de benzocaína com melhores resultados foram de 87,5 e 100mg.L-1. O eugenol proporcionou demora na indução e na recuperação dos animais, além de ter apresentado mortalidades quando as doses anestésicas foram elevadas.

The aim of this work was to evaluate the induction and recuperation time of quinguio (Carassius auratus) exposed to two anesthetics, eugenol and benzocaine. 128 juveniles with 2.07±0.53g of average weight and 5.51±0.56cm of total length were used. The benzocaine proved to be more efficient than the eugenol regarding the time in inducing a coma and recovering flight, as well as survival. The better results of benzocaine doses were 87.5 and 100mg.L-1. The eugenol resulted in a delay of animal induction and recovery, and also presented mortalities when the anesthetics doses were increased.