Hydrogels: Biological Properties and Applications

Description

Hydrogels are a particular class of compounds of which the major constituent is wa ter. In fact, water is present in the hydrogel up to 90% and is contained in a scaffold which is generally polymeric and obviously hydrophilic. As a result, hydrogels re semble each other even though obtained from different polymers. Nevertheless, the polymeric matrix gives particular characteristics to the hydrogel leading to applica tions in different fields. Water is the main element of the human body, thus hydrogels are excellent struc tures to favourably shelter proteins, cells etc., without altering their characteristics and properties. This is why hydrogels are mainly designed and synthesized for their usein thebiologicalfield;hence the name biohydrogels. Their propertiespoint totheir use as scaffolds for stem cells which has turned out to be a very promising technique for tissue and organ regeneration. For this reason their investigation falls within the Biomaterials Science. Paradoxically, the conceptual simplicity of hydrogelsupto nowhas led to a super ficialstudy of their chemistry, chemical physics and mechanics preventing their wider application in the human body due to a lack of knowledge of biological component interactions. For example, it is not clear, yet, how to store hydrogels without alter ing their characteristics. In fact, hydrogels re-hydrated after lyophylization or oven drying, generally show corrupted properties once swollen in water, in comparison with their native counterparts.