Chitosan (CS) is well-known for its biological properties, especially its ability to induce tissue cicatrization. However, considerable research proved that CS presents a high inflammatory response and poor mechanical properties. For these reasons, we decided to use chitosan (CS) functionalized GO by a covalent bond (CS-GO). Due to the resistant structure of the GO and the high presence of oxygen functional groups on it, it will enhance the biocompatibility of the material. The data obtained in this investigation aimed to prove the possible application of CS-GO in regenerative medicine. For this reason, it was performed an In vitro analysis using brine shrimp to prove materials biocompatibility and gingival fibroblasts for a cell growth test.

Determinación de la actividad antioxidante y antimicrobiana de residuos de mora (Rubus glaucus Benth) Determination of the antioxidant and antimicrobial activity of blackberry residues (Rubus glaucus Benth

Graphene oxide (GO) has recently gained attention as a scaffold reinforcing agent for tissue engineering. Biomechanical and biological properties through a synergistic effect can be strengthened when combined with other materials such as chitosan (CS). For that reason, chitosan was used for Graphene Oxide (GO) functionalization through an amide group whose formation was evident by bands around 1600 cm À1 in the FTIR analysis. Furthermore, bands located at 1348 cm À1 (D band), 1593 cm À1 (G band), and 2416 cm À1 (2D band) in the RAMAN spectrum, and the displacement of the signal at 87.03 ppm (C5) in solid-state 13 C-NMR confirmed the amide formation. Films including the CS-GO compound were prepared and characterized by thermogravimetric analysis (TGA), where CS-GO film presented a lighter mass loss (~10% less loosed) than CS due probably to the covalent functionalization with GO, providing film thermal resistance. The CS-GO films synthesized were implanted in Wistar rats' subdermal tissue as a first approximation to the biological response. In vivo tests showed a low inflammatory response, good cicatrization, and advanced resorption at 60 days of implantation, as indicated by histological images. It was evidenced that the covalent union between CS and GO increased biocompatibility and the degradation/resorption capacity, demonstrating tissue regeneration with typical characteristics and tiny remnants of implanted material surrounded by a type III collagen capsule. These results show the potential application of the new synthesized films, including the CS-GO compound, in tissue engineering.

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Recent research has shown the importance of plant extracts as powerful antioxidants owing to the presence of chemically active components such as polyphenols, anthocyanins, flavonoids, among others. This synergy of the components becomes a possible alternative to the use of antioxidants of synthetic origin. In this study, Syzygium cumini fruit peel was used to determine the antioxidant activity against singlet oxygen. The extract showed appreciable amounts of phenolic groups (about 8.55 AGE mg/g fruit weight). HPLC-DAD characterization showed at least 3 anthocyanins of higher relative abundance (malvidin 3,5-diglucoside, delphinidin 3,5-diglucoside and petunidin 3,5-diglucoside). The percentage of quenching of singlet oxygen was determined at different concentrations of the ethanolic extract, finding a value of 60% at a concentration of 0.39 mg/mL.