Chitin nanocrystal enhanced wet adhesion performance of mussel-inspired citrate-based soft-tissue adhesive

Chitin nanocrystal (ChiNC) with its good biodegradability and biocompatibility as well as rod-like structure characteristic has become one of excellent nanofillers to enhance mechanical properties and bioactivity of biomedical polymers. For further extending its application fields, here, we dispersed ChiNC into a recently synthesized citrate-based tissue adhesive (POEC-d) and explored its effects on the adhesion and cytocompatibility of the adhesive. POEC-d, a mussel-inspired wet adhesive, was prepared by a one-pot melt polycondensation of 1, 8-octanediol, poly(ethylene oxide) (PEO), citric acid (CA) and dopamine (DA). The good water-solubility of POEC-d allowed facilely blending ChiNC and POEC-d to ultimately acquire POEC-d/ChiNC nanocomposite adhesives. The results showed the ChiNCs were finely dispersed in the POEC-d matrix and endowed the adhesive with extra crosslinks to enhance the bulk cohesion property. Synchronously, the lap-shear adhesion strengths measured by bonding wet porcine skins considerably improved with increasing the ChiNC content. In addition, the POEC-d/ChiNC nanocomposite adhesives exhibited lower swelling ratio as compared to the POEC-d adhesive as well as good cytocompatibility, revealing their superior applicability in soft-tissue adhesion.