Biocompatible 3D Printed Chitosan-Based Scaffolds Containing α-Tocopherol Showing Antioxidant and Antimicrobial Activity

Active dressings acting on multiple fronts are requested in the field of care for chronic skin ulcers in order to ameliorate patient compliance and tissue restoration. Currently, three-dimensional polymeric hydrogels are widely investigated; however, no prototypes aiming to control oxidative stress and bacterial proliferation in the wound bed have been developed up until now. The present work describes the formulation of a novel chitosan-based printable material containing alpha-tocopherol at stable dosages to obtain reproducible 3D scaffolds possessing antioxidant and antimicrobial activity without the use of organic solvents. Stability assays mimicking the manufacturing process and storage conditions reveal no significant drug loss. Chemico-physical characterizations including porosity and behavior after dehydration/hydration demonstrate that the dressings are highly porous, can be dehydrated up to 80%, and can recover more than 90% of water upon 1 h of rehydration. Elasticity determined by stress/strain tests was higher than human skin and was sufficiently resistant for potential clinical manipulation. Footage of fibroblasts in in vitro cultures demonstrated the biocompatibility of the constructs over 28 days. Finally, scaffolds loaded with alpha-tocopherol showed dose-dependent antioxidant activity (up to 80% in less than 1 h), while antimicrobial action versus multi-drug resistant strains of Pseudomonas aeruginosa and Staphilococcus aureus was assessed by inhibition rings obtained through the Kirby-Bauer technique. The proposed hydrogels can be useful as dressings for the treatment of chronically infected wounds.