Gellan gum-based hydrogels are disclosed herein for in vitro cell culture and tissue engineering and regenerative medicine applications. Such gellan gum-based hydrogels may be used alone or combined with live cells and/or biomolecules for application in humans and/or animals. Chemical modification of gellan gum with selected ion-chelating substituents affords novel gellan gum hydrogels endowed with tunable physicochemical and biological properties. The modified gellan gum hydrogels described herein present advantages over existing hydrogel systems, including solubility, ionic crosslinking versatility, ease of formulation and injectability and greater adhesiveness within biological tissues and surfaces, whilst maintaining encapsulated cells viable during long culture periods and up-regulating the expression of healthy extracellular matrix markers.