Integrated processes (HPSE+scCO2) to prepare sterilized alginate-gelatine-based aerogel.

Biopolymers application in biomedical areas has been limited due to the physicochemical degradation that occurs using conventional processing/sterilization methods (e.g., steam heat, γ-radiation, ethylene oxide). Aiming to avoid/minimize degradation and preserve their properties, supercritical carbon dioxide (scCO2) has been proposed as an alternative sterilization method for such materials. ScCO2 can simultaneously be used as a drying method to produce aerogels (i) and sterilize them (ii). However, a solvent exchange is required to prepare the alcogel from hydrogel, achievable through high-pressure solvent exchange (HPSE) (iii). This study integrated three processes: HPSE, scCO2 drying, and sterilization to prepare alginate-gelatine sterilized aerogels. Two scCO2 sterilization methods were tested. Results showed that sterilization did not compromise the aerogels' chemical, thermal and swelling properties. Conversely, Young's Modulus increased, and BET surface area decreased, due to the structural changes caused by the fast pressurization/depressurization rates applied during sterilization. Regarding the sterilization efficiency, results showed a reduction in contamination throughout the process, achieving a SAL of 10-4. The sterilized aerogels were non-cytotoxic in vitro and showed improved wound-healing properties. The innovative integrated process produced decontaminated/sterile and ready-to-use aerogels reducing process time by 75 %, from 2 days up to 12 h without compromising the aerogel's properties.

Evaluation of Biological Activity of Polygala Boliviensis in Experimental Models.

The plants of the genus Polygala (Polygalaceae) are employed in folk medicine for the treatment of several pathologies, including disorders of the bowel and kidney, as anesthetic, expectorant and anti-inflammatory. The present study was undertaken to investigate the antiedematogenic and antinociceptive activities of methanolic extract of Polygala boliviensis A. W. Benn (MEPB) in mice. The antinociceptive activity of MEPB was evaluated using the writhing, formalin, and tail immersion tests. The carrageenan-induced paw edema test was used to assess the antiedematogenic activity of MEPB. Mice motor performance was evaluated in the rota rod and open field tests and the acute toxicity were evaluated over 14 days. High-performance liquid chromatography was used to determine the fingerprint chromatogram of MEPB. Oral administration of MEPB (75- 600 mg/kg) reduced the number of writhing induced by acetic acid. In the formalin test, the oral pre-treatment with MEPB (75 - 600 mg/kg) produced a dose-related inhibition only of the late phase. MEPB (300 and 600 mg/kg) reduced the carrageenan-induced paw edema. In contrast, the treatment with MEPB (300 and 600 mg/kg) did not prevent the thermal nociception in the tail immersion test. MEPB (600 mg/kg)-treated mice did not show any motor performance alterations. Over the study duration of 14 days, there were no mortality or toxic signs recorded in the group mice given 6000 mg/kg of MEPB. The present study demonstrated, for the first time, the antinociceptive and antiedematogenic properties of Polygala boliviensis.

Fluorescent Canthin-6-one Alkaloids from Simaba bahiensis: Isolation, Identification, and Cell-Labeling Properties.

Canthin-6-one alkaloids, which are present in plants of the genus Simaba, are natural compounds that are capable of acting as fluorescent probes. However, the chemical composition and fluorescent properties of most species of this genus have not been analyzed. The objective of this study was to characterize the fluorescent properties of an extract of S. bahiensis and identify the chemical entities responsible for these properties. In addition, the cell-labeling properties of the fluorescent dye from A and of the isolated compounds were characterized by confocal fluorescence microscopy and flow cytometry. One quassinoid and three fluorescent alkaloids were isolated from S. bahiensis, all compounds were identified by using NMR spectroscopy and high-resolution mass spectrometry. Staining experiments and HPLC-FL analysis shown that canthin-6-one alkaloids are the main green fluorescent compounds in the analyzed dyes. All compounds evaluated showed a cytoplasmic marker with a residence time of 24 h. The present study is the first to describe the presence of canthin-6-one alkaloids in S. bahiensis, in addition to demonstrating promising cell-labeling properties of fluorescent compounds from S. bahiensis with broad emission wavelengths.