Abstract
Bioadhesives face significant challenges in achieving both wet tissue adhesion and deformation tolerance for bladder sealing. This study presents a "covalent/non-covalent" coupled bidirectional anchoring strategy to develop a high-performance protein-based Janus patch. The patch comprises a deformable hydrogel bottom layer (composed of renewable-source gelatin, anionic zein colloid, and genipin) and a bidirectional anchoring adhesive layer (composed of poly-lysine, anionic zein colloid, and genipin). The former ensures stress dissipation and anti-adhesion, while the latter enables initial strong wet adhesion to both the tissue and bottom layer via ionic interactions, followed by subsequent covalent anchoring at both the tissue-adhesive and hydrogel-adhesive interfaces. The underlying mechanism relies on the dynamic dissociation/reassociation of ionic bonds for exceptional energy dissipation and deformation tolerance, supplemented by permanent covalent anchoring that ensures long-term, robust interfacial adhesion. Consequently, the Janus patch exhibits superior bladder adhesion (132.5 J m~(-2)), high strain tolerance (>100%), and remarkable burst pressure resistance (108.1 cmH2O). In vivo/vitro tests confirm its reliable bladder adhesion, post-surgical anti-adhesion capability, exceptional biocompatibility, and automatic degradability, enabling effective bladder sealing and repair without post-surgical removal. This strategy overcomes key limitations of conventional bioadhesives, showing great promise for dynamic tissue sealing applications.
NETL
NSTL
Wiley