Hydrogels

Hydrogels are 3D network of hydrophilic polymers that swell when they come into contact with water^1-3. These hydrogels are able to retain a large volume of water whilst keeping its structure intact, this is due to the cross-linking of the individual polymer chains. There are many different types of hydrogels as they can be either physical, chemical or biochemical². Physical hydrogels change from a liquid to a gel when they are exposed to a change in environmental conditions such as temperature, pH, ionic concentration, chemical gels use covalent bonds these bonds introduce mechanical integrity to the gel making it more resistance to degradation when compared to other weaker materials. The final type of hydrogel is biochemical, these hydrogels use biological agents such as enzymes or amino acids to participate in the gelation process².