A Conformable and Tough Janus Adhesive Patch with Limited 1D Swelling Behavior for Internal Bioadhesion

Advanced bioadhesion techniques have offered unprecedented opportunities for life-saving internal surgical procedures. However, most existing bioadhesives failed to rapidly establish long-lasting reliable biointerface and effectively reconstruct normal physiological function in the body fluid-rich and inevitable dynamic internal environment. Herein, a PEGylated poly(glycerol sebacate)-based Janus adhesive patch (PEGS-based JAP) is developed by integrating physically crosslinked guanidinylated PEGS (PEGSG) and acryloylated PEGS-chemically crosslinked poly(acrylic acid)-N-hydrosuccinimide ester (PEGSA-crosslinked PAAc-NHS) with a single-sided zwitterionic polymer-interpenetrated layer. The dry JAP can rapidly absorb the unpleasant interfacial water and effectively form strong physical interactions with wet tissues. Benefiting from the amphiphilic nature of PEGSG and a simple spatial-confined drying process, the JAP is allowed to resist excessive swelling and limitedly swell along one direction to avoid deterioration of the as-established conformable patch-tissue interface. Moreover, covalent interactions formed subsequently can further improve the adhesive strength and ensure a long-lasting reliable adhesion. Meanwhile, the notch-insensitive and puncture-resistant JAP can achieve tough adhesion to adapt to the dynamic conditions owing to the highly efficient energy-dissipation mechanism of the physically cross-linked network. Combining the above ideal features with the desirable postoperative anti-adhesion ability, the PEGS-based JAP is demonstrated to be a promising candidate for internal tissue adhesion and function reconstruction.