The microdiscectomy used for the treatment of intervertebral disc disorders leaves an open incision in the annulus fibrosus that must be sealed to avoid re-herniation and other subsequent degenerations. In this study, we developed an injectable and in situ polymerizable polyurethane adhesive as a long-term post-surgical annulus fibrosus repair strategy. It was investigated the chemical structure of the urethane-based adhesive and its physico-chemical, viscoelastic, kinetic, and in vitro cytotoxic properties. The adhesive formulated from the polycarbonate diol with the highest molar mass was the one that exhibited a compressive behavior closest to the intervertebral disc outer region, and therefore, the most suitable for restoration. This adhesive showed 18-day stability under moisture and required a preparation time of 10 h at 60°C before use. The material also adhered covalently to gelatin (without catalyst or initiator) and positively impacted cell proliferation after its polymerization, which are essential requirements for clinical translation. These findings confirmed the ability of the polyurethane adhesive to act as an annulus fibrosus sealant, although further improvements in its formulation are necessary.

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Trifluoromethylated β-enamino diketones undergo type 1,2-addition leading to regioselective synthesis of trifluoromethylated azoles containing an azomethine group.

An efficient one-pot method is described for the highly regioselective synthesis of α-ketoamide N-arylpyrazoles from secondary β-enamino diketones. For this, the key intermediate, 4-acyl 3,5-dihydroxypyrrolone, was generated in situ and underwent bimolecular nucleophilic substitution at C-5 by arylhydrazine, with subsequent heterocyclization at the carbonyl carbon of the acyl group. This strategy allowed for regiochemical control of α-ketoamide N-arylpyrazoles from β-enamino diketones and arylhydrazines.

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Cytotoxic and genotoxic effects were demonstrated in all extracts and fractions used, although only EAF showed mutagenic effects by CBMN, but not by Salmonella/microsome assay. Our results suggest that flavonoids, phenylpropanoids, coumarins, and diterpenes may be responsible for the cytotoxic, genotoxic and mutagenic effects observed.

Pheromones have been used for monitoring and control of insect pests in crops, reducing the use of pesticides. However, among obstacles for this technology to be more useful, is the control and time to release. In this way, this work aims the evaluation of the release of pheromones using micro/nanofibers of ethylene-vinyl acetate (EVA) produced by blow spinning. Solutions with 0.5-15 wt % EVA were prepared based on the solubility parameter of the copolymer. Fibers were obtained from solutions in the semidiluted concentration regime. Synthetic sex pheromones from the oriental fruit moth, Grapholita molesta and citrus leafminer Phyllocnistis citrella were incorporated into the micro/nanofibers. The morphology and structure of these fibers were evaluated employing field emission scanning electron microscopy and wide-angle X-ray diffraction. The fibers sizes (95-426 nm) were dependent on the feed rate of the solution. As a result, pheromone release has occurred linearly over 10 weeks, as determined by thermogravimetry analysis. The solubility parameter influences the amount incorporated in the fiber and the rate of pheromone release. The proposed fiber/pheromone system is interesting since it reduces the use of actives and can be used in several planting cycles and reused.

No abstract