While self-healing, hybrid hydrogel lacking covalent reticulation can be suitable for certain biomedical applications, they often have weak mechanical properties. To address this limitation, covalent bonds are introduced within the gel matrix through various chemical or enzymemediated approaches. The resulting hybrid hydrogels usually demonstrate enhanced robustness compared to the non-crosslinked counterparts and are easily tunable by adjusting the crosslinking degree, which can ultimately enable precise control on drug delivery.