Abstract: | The engineering of bioadhesives to bind and conform to the complex contour of tissue surfaces remains a challenge. We have developed a novel moldable nanocomposite hydrogel by combining dopamine‐modified poly(ethylene glycol) and the nanosilicate Laponite, without the use of cytotoxic oxidants. The hydrogel transitioned from a reversibly cross‐linked network formed by dopamine–Laponite interfacial interactions to a covalently cross‐linked network through the slow autoxidation and cross‐linking of catechol moieties. Initially, the hydrogel could be remolded to different shapes, could recover from large strain deformation, and could be injected through a syringe to adhere to the convex contour of a tissue surface. With time, the hydrogel solidified to adopt the new shape and sealed defects on the tissue. This fit‐to‐shape sealant has potential in sealing tissues with non‐flat geometries, such as a sutured anastomosis. |