Conductive and antibacterial hydrogel bio-adhesives based on quaternized chitosan, aldehyde dextran, and polydopamine/polypyrrole nanocomposites

Conductive hydrogels with strong adhesion and antibacterial activity have demonstrated great potential for tissue regeneration applications. In this paper, polypyrrole-doped polydopamine (PDA@PPy) nanocomposites were encapsulated in a polymer hydrogel prepared using quaternary ammonium chitosan (QCS) and aldehyde dextran (ODex), yielding composite hydrogels (QOP). The QOP hydrogels were formed from the pre-solutions within 30 s, and Schiff-base bonds were observed in the polymer network, as verified by Fourier transform infrared (FT-IR) analysis. The fabricated QOP hydrogels displayed a three-dimensional (3D) interconnected porous microstructure, as confirmed by scanning electron microscopy (SEM) and X-ray computed microtomography (Micro-CT) analyses. With increasing PDA@PPy nanocomposite content, the conductivity of QOP hydrogels increased. Furthermore, the QOP hydrogels exhibited good self-healing abilities and strong adhesion to the surfaces of different materials and organs, including rubber, plastic, glass, metal, heart, pancreas, lung, kidney, stomach, liver, and human skin. The −2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid ammonium salt (ABTS) free-radical scavenging rates of over 80% by QOP hydrogels confirmed their excellent antioxidant ability. In addition, the QOP hydrogels demonstrated effective antibacterial activity against the typical bacteria, Escherichia coli ( E. coli, Gram-negative) and Staphylococcus aureus ( S. aureus, Gram-positive). The QOP hydrogels also performed excellent cytocompatibility and good cell migration ability, confirmed using the Cell Counting Kit-8 (CCK-8) approach, fluorescent staining, and cell scratch assay. The available data provide a facile strategy for fabricating a hydrogel bio-adhesive with good antioxidant and potential antibacterial activity for biomedical applications.