Natural polymer-polyphenol bioadhesive coacervate with stable wet adhesion, antibacterial activity, and on-demand detachment.

Medical adhesives are arising as an important clinical tool as adjuvants for sutures and staples in wound closure and healing, and in the achievement of hemostasis. However, clinical adhesives combining cytocompatibility, as well as strong and stable adhesion in physiological conditions are still in demand. Herein, a mussel-inspired strategy is explored to produce adhesive coacervates using tannic acid (TA) and methacrylate pullulan (PUL-MA). TA|PUL-MA coacervates mainly comprise van der Waals forces and hydrophobic interactions. The methacrylic groups in PUL backbone increase the number of interactions in the adhesives matrix, resulting in enhanced cohesion and adhesion strength (72.7 Jm -2 ), comparing to the non-methacrylated coacervate. The adhesive properties were kept in physiologic-mimetic solutions (72.8 Jm -2 ) for 72 h. The photopolymerization of TA|PUL-MA enabled the on-demand detachment of the adhesive. The poor cytocompatibility associated with the use of phenolic groups was here circumvented by mixing reactive oxygen species (ROS)-degrading enzyme in the adhesive coacervate. This addition did not hamper the adhesive character of the materials, neither their anti-microbial nor hemostatic properties. This affordable and straightforward methodology, together with the tailorable adhesivity even in wet environments, high cytocompatibility and anti-bacterial activity, enable foreseeing TA|PUL-MA as a promising ready-to-use bioadhesive for biomedical applications. This article is protected by copyright. All rights reserved.