Adhesive and antibacterial films based on marine-derived fucoidan and chitosan

Marine-derived polymers are environmentally friendly and sustainable biomaterials that have structural similarities with the main components of the extracellular matrix. Moreover, some marine polymers have specific bioactivity that can be transferred to the systems made of these biomolecules. Herein, we developed antibacterial adhesive films combining two marine polysaccharides, namely, fucoidan and chitosan. Fucoidan was functionalized with catechol groups (FCat) to improve its adhesive properties. This modification enhanced also the fucoidan antibacterial properties: while fucoidan is active against Gram-positive bacteria, FCat showed bactericidal activity against Gram-positive and Gram-negative bacteria. To improve the processability and mechanical properties, FCat was blended with chitosan and solvent-casted to obtain films. These films exhibited an adhesion strength similar to the one of clinically used natural adhesives and no cytotoxicity: fibroblastic cells attached and remained viable on the films. Altogether our results demonstrated that the developed antibacterial and adhesive films are a feasible alternative of cytotoxic synthetic adhesives used for soft tissue healing applications.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) and the European program FEDER/FEEI for the financial support through the PTDC/BTM-MAT/28123/2017 project. FCT is also acknowledged for the PhD scholarship SFRH/BD/143209/2019 granted to C.C. This article has also been prepared with the support of REMIX Project, funded by the European Union’s Horizon 2020 Research and Innovation programme under the Maria Sklodowska-Curie grant agreement no. 778078. Dr. Luisa Rodrigues is acknowledged for performing the XPS analysis