(A) Design and processing of adhesive nanocomposite hydrogels based on Laponite® nanoclays. Multi-arm poly(ethylene glycol) (PEG) was capped with the catechol groups. (B) Curing occurred via a mixture of dynamic interactions and covalent bonds between the catechol-functionalized PEG and Laponite®. (C) Reversible and loose crosslinking as well as adhesion through catechol groups, and (D) moldability of the cured hydrogels. (E) Application of the adhesive hydrogel to the convex pericardium and collagen tubing and the mechanism of covalent bonding explaining adhesion. Reproduced with permission from ref 300. Copyright 2017, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. (F) Schematic of nanocomposite hydrogels based on PDA-coated carbon nanotubes (CNT). The UV-assisted crosslinking of the hydrogel network and internal strong hydrogen-bonding interactions between the polymer molecules led to gelation in the hydrogels. Reproduced with permission from ref 15. Copyright 2018, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.