Poly(ε-caprolactone), an aliphatic polyester with biodegradability and cytocompatibility, has been used to create scaffolds for tissue engineering purposes. However, the hydrophobicity and low water absorptivity of poly(ε-caprolactone) reduce cell anchorage on their membranes. Here, poly(ε-caprolactone)-based scaffolds were prepared by electrospinning of poly(ε-caprolactone)chitosan blend, and poly(ε-caprolactone)-dexamethasone solution. Chitosan and dexamethasone play an essential role to increase the scaffolding performance of poly(ε-caprolactone)-based electrospun membranes. A poly(ε-caprolactone) membrane without chitosan and dexamethasone did not provide satisfactory results to promote cell culture of adipose mesenchymal stem cells (AMSCs). Compared to the poly(ε-caprolactone)-dexamethasone surface, poly(ε-caprolactone)chitosan membrane imparts better cytoskeletal reorganization, and cell spreading, increasing the strength of cell attachment. Also, poly(ε-caprolactone)-chitosan composite provides strong antimicrobial activity against Pseudomonas aeruginosa (ca. 90% inhibition). Therefore, the poly(ε-caprolactone)-chitosan composite is a better alternative to treat skin diseases and promote skin regeneration than conventional approaches based on dexamethasone.

Pectin and chitosan films containing glycerol (Gly) at 5, 10, 15, 20, 30, and 40 wt % were prepared in an aqueous HCl solution (0.10 M) by the solvent evaporation method. The unwashed film (UF) containing 40 wt % Gly (UF40) had elongation at break (ε, %) of 19%. Washed films (WFs) had high tensile strength (σ > 46 MPa) and low elongation at break (ε, <5.0%), enabling their use in food packaging applications. The polymers’ self-assembling occurred during the washing, increasing the stiffness. The XPS analysis suggests that some HCl is lost during the drying process, resulting in a low acid content on the UF surfaces. The UF40 (at 5.0 mg/mL) exhibits cytocompatibility toward mammalian cells and antimicrobial and anti-adhesive properties against Escherichia coli. The remaining HCl in the UF40 can be a disadvantage for food packaging applications; the UF40 (∅ = 8.5 mm; 55 μm thickness) releases H3O+/HCl, reducing the pH to approximately 3.0 when kept in 200 mL distilled water for approximately 30 min. Therefore, we propose the use of UF40 to coat commercial food packaging. The UF40 has low permeability to water vapor and oxygen and works as a barrier against ultraviolet light. The UF40 is also colorless and completely transparent. The UF40 maintained tomatoes’ structural integrity for 18 days at room temperature with no oxidation or microorganism contamination. This paper presents a critical viewpoint concerning chitosan-based films with antimicrobial activities.

Este trabalho foi desenvolvido por bolsistas do PIBID Química UTFPR Apucarana. Foi escolhida a vitamina C como tema de estudo para ensinar funções orgânicas e a proposta foi estruturada nos três momentos pedagógicos de Delizoicov. Foi realizada uma problematização inicial sobre a Vitamina C, levantando questões sobre o conhecimento prévio dos alunos. No segundo momento, foi apresentado um vídeo e discutido o assunto, havendo uma interação professor-aluno e aluno-aluno. No terceiro momento os alunos realizaram um experimento para comparar o teor de vitamina C em diferentes frutas. Este foi aplicado de forma problematizada, direcionando os estudantes a levantar hipóteses e sugerir explicações para os eventos observados. Após as explicações científicas os alunos responderam um questionário sobre a prática, demonstrando um bom entendimento do assunto. Os estudantes responderam novamente o questionário inicial, demonstrando evolução de seus conceitos, confirmando que a metodologia mostrou-se eficiente no ensino de funções orgânicas.

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