Hydrogels: Biological Properties and Applications

The studies on Biohydrogels have had a rapid, exponential evolution in the last

decades. Starting from one of the first applications of hydrogels in surgery,

polyvinylalcohol crosslinked with formaldehyde under the trade name of Ivalon, we

passed through PolyHema hydrogels as contact lens materials, hydrophilic

polyurethanes (HPU), biodegradable hydrogels for both reconstructive surgery and

pharmaceutical delivery systems, and finally more recently, one decade old, the

thermoreversible and transient network hydrogels. Of course all these classes of

hydrogels have been always and continuosly studied, improving their performance and

field of applications. Recently, most of them have been used as scaffolds for cells,

even stem ones, for regenerative applications (tissue engineering). Nevertheless

hydrogels are odd materials and many studies still have to be carried out to fully

understand their behaviour from mechanical, physicochemical and biological point of

view.