PROTECTED - By-PROducts based innovative TEchnologies for green and low Cost acTivE wounD dressings

Keratin is a biocompatible protein that promotes cell adhesion, migration, and proliferation. Keratin-based nanofibers (KS-NFs) can be produced using a technique involving an electric field called electrospinning. KS-NFs have demonstrated potential in wound healing due to their high surface area, porosity, and ability to mimic the extracellular matrix. Polyphenols are a group of compounds, widely present in the plant kingdom, with biocompatible, antioxidant, and antibacterial properties. The goal of the PROTECTED project, representing the framework of this study, is to develop a new technology for active wound dressings that not only promotes effective and active healing but also incorporates environmentally friendly and sustainable materials and processes. In this direction, keratin and the functionalizing polyphenols are extracted from discarded wool and agri-food by-products, respectively, offering green and cost-effective sources to be applied also in the biomedical field. The effectiveness in tissue repair applications given by keratinpolyphenols nanofibers can be seen in the combination of antioxidant, anti-inflammatory and antibacterial properties of phenolic compounds with the support to cell growth provided by keratin. In this study, keratin has been successfully extracted from discarded wool and electrospun in blend with PEO from a water-based solution. Active polyphenols were extracted from agri-food by-products, through green procedures, and have effectively functionalized to keratin. Zeta potential measurements confirmed the presence of polyphenol functionalization. A biological evaluation was also carried out. KS-NFs supported the adhesion, spread and metabolic activity of human fibroblasts, as well the presence of bioactive polyphenols conferred a bacteriostatic effect. Future perspectives of this study include the development of functionalized polyphenols to enhance pH-dependent color change, the functionalization of keratin fibers with novel polyphenols and 3D printing of keratin. This study was carried out within the PROTECTED project (P2022XT785) and received funding from the European Union - NextGenerationEU, Missione 4 Componente 1 - CUP B53D23027682768.