A large number of hybrid hydrogels feature composite structures characterized by noncovalent/physical interactions among the polymer chains of the hydrogel matrix and dispersed nano-objects. It results in hybrid systems where the structural stability depends solely on the dispersing material in some cases, while in others the nano-objects themselves are involved in reinforcing the hydrogel. Such stabilization generally involves electrostatic, hydrophobic/hydrophilic interactions, as well as formation of hydrogen bonds. Other hydrogels rely on chelation/coordination reactions, macromolecular recognition (e.g., COL hydrogel/COL-binding peptides at the surface of liposomes), host-guest or entropy-driven interactions.