Hydrogels are a wide range of materials that are composed primarily of water. Research interest in hydrogels has increased significantly in the recent years because of their multitude of application, but more recently, and importantly, in biomedicine. The scientific community’s interest in hydrogels is evidenced by steady upward trend in the number of annual publications and patents. New hydrogels are reported more frequently than ever, and knowledge about their characteristics and their practical utility is expanding each day. The proposed special issue will solicit manuscripts from researchers in the field compiling recent advances in design of hydrogels, characterization of material properties, and knowledge of the nature of the microenvironments of these systems. It is expected that publishing a special issue on hydrogels will tap into this scientific community’s interest, directing more attention towards the journal which will serve to garner higher readership and citations. Manuscripts submitted to this special issue will be subject to a high-standard scientific peer review process.