Toxicity of oleate-based amino protic ionic liquids towards Escherichia coli, Danio rerio embryos and human skin cells.

Protic ionic liquids (PILs) have been widely employed with the label of "green solvents'' in different sectors of technology and industry. The studied PILs are promising for corrosion inhibition and lubrication applications in industry. Industrial use of the PILs can transform them in wastes, due to accidental spill or drag in water due to washing, that can reach water bodies. In addition, the handling of the product by the workers can expose them to accidental contact. Thus, the aim of this work is to evaluate the toxicity of PILs 2-hydroxyethylammonium oleate (2-HEAOl), N-methyl-2-hydroxyethylammonium oleate (m-2HEAOl) and bis-2-hydroxyethylammonium oleate (BHEAOl) towards Escherichia coli, zebrafish embryos, model organisms that can be present in water, and human skin cells. This is the first work reporting toxicity results for these PILs, which constitutes its novelty. Results showed that the studied PILs did not inhibit E. coli bacterial growth but could cause human skin cells death at the concentrations of use. LC50 values for zebrafish eggs were 40.21 mg/L for 2HEAOl, 12.92 mg/L for BHEAOl and 32.74 mg/L for m-2HEAOl, with sublethal effects at lower concentrations, such as hatching retarding, low heart rate and absence of free swimming.

HA-hybrid matrix composite coating on Ti-Cp for biomedical application.

Calcium phosphate coatings have been applied to titanium metal substrates and their alloys as a synergistic alternative capable of combining the mechanical properties of metals and the excellent bioactive properties provided by ceramic materials. However, the unsatisfactory adhesion of hydroxyapatite coatings on metallic substrates, as well as their limitation when subjected to mechanical stresses have been reported as a limitation. Biofunctional coatings have been proposed as an alternative to single ceramic coatings, aiming at optimizing the long-term clinical success of biomaterials such as Ti. This work aims at evaluating the morphological properties and biological behavior of Ti-cp coated with matrix composite coating hydroxyapatite-containing hybrid. The hybrid matrix was obtained from TEOS and MTES silicon precursors, with dispersed hydroxyapatite suspended by dip coating. For the morphological characterization FTIR, SEM/FEG, AFM and contact angle measurement were used. Biological behavior was evaluated for toxicity, cell viability and the osteogenic differentiation capacity of mesenchymal stem cells. The composite coatings obtained showed regular dispersion of hydroxyapatite particles in the hybrid matrix, with uniform coating adhering to the Ti-Cp substrate. Nevertheless, although they provided similar viability behavior of mesenchymal stem cells to the Ti-Cp substrate, the evaluated coatings did not present osteoinductive properties. This result is probably due to the pronounced hydrophobic behavior caused by the incorporation of HA.