[en] Oral administration of drugs presents important limitations, which are frequently not granted the importance that they really have. For instance, hepatic metabolism means an important drug loss, while some patients have their ability to swell highly compromised (i.e. unconsciousness, cancer…). Sublingual placement of an accurate Pharmaceutical Dosage Form is an attractive alternative. This work explores the use of the β-chitosan membranes, from marine industry residues, composed with marine sediments for dual sublingual drug delivery. As proof of concept, the membranes were loaded with a hydrophilic (gentamicin) and a hydrophobic (dexamethasone) drug. The physico-chemical and morphological characterization indicated the successful incorporated of diatomaceous earth within the chitosan membranes. Drug delivery studies showed the potential of all formulations for the immediate release of hydrophilic drugs, while diatomaceous earth improved the loading and release of the hydrophobic drug. These results highlight the interest of the herein developed membranes for dual drug delivery.

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[en] Peripheral nerve injuries have produced major concerns in regenerative medicine for several years, as the recovery of normal nerve function continues to be a significant clinical challenge. Chitosan (CHT), because of its good biocompatibility, biodegradability and physicochemical properties, has been widely used as a biomaterial in tissue engineering scaffolding. In this study, CHT membranes were produced with three different Degrees of Acetylation (DA), envisioning its application in peripheral nerve regeneration. The three CHT membranes (DA I: 1%, DA II: 2%, DA III: 5%) were extensively characterized and were found to have a smooth and flat surface, with DA III membrane having slightly higher roughness and surface energy. All the membranes presented suitable mechanical properties and did not show any signs of calcification after SBF test. Biodegradability was similar for all samples, and adequate to physically support neurite outgrowth. The in vitro cell culture results indicate selective cell adhesion. The CHT membranes favoured Schwann cells invasion and proliferation, with a display of appropriate cytoskeletal morphology. At the same time they presented low fibroblast infiltration. This fact may be greatly beneficial for the prevention of fibrotic tissue formation, a common phenomenon impairing peripheral nerve regeneration. The great deal of results obtained during this work permitted to select the formulation with the greatest potential for further biological tests. - Highlights: • Three chitosan membranes were produced with very specific degrees of acetylation (DA I: 1%, DA II: 2%, DA III: 5%). • Physicochemical characterization of the membranes showed their suitability for peripheral nerve regeneration purposes. • In vitro cellular tests confirmed the potential of the membranes as peripheral nerve regeneration systems. • The results indicated that DA III membrane should be the one considered for further peripheral nerve regeneration studies.