Hydrogels are polymeric matrices that can entrap large quantities of water or biological fluids which are insoluble in aqueous environments.
As hydrogels are biocompatible, tunable, biodegradable, porous and have a properly mechanical strength they have advantages in comparison to other biomaterials.
Generally we can divide hydrogels by their nature (natural,semi-synthetic and synthetic) and their features (type of crosslinking, stiffness, elasticity, cell adhesion, porosity,degradation properties and cell-specifuc bioactivity). So called “smart” hydrogels being responsive to stimuli (e.g. temperature, pH, photo/light, electro- and magnetic, glucose and biologicaöl/biochemical) are of high interest as organoids and/or cells are easily accesible.
It depends all on your application, cell type and-read out system which kind of hydrogels or 3D cell culture technnology might be the best.