ABSTRACT
Hydrogels are colloidal mixtures consisting of water as a liquid phase and a solid phase mostly made of natural or synthetic polymer backbones. Hydrogels can be used for different technologic applications, mainly trying to get an innovative or higher performance that depends on the composition. Hydrogels are easily prepared by many methods, which is very attractive for technological intentions. Hydrogels of natural origin can be derived from protein polymers, such as collagen and elastin, and polysaccharide polymers, such as alginate or chitosan, among others. Synthetic hydrogels are obtained from the polymerization of monomers such as acrylic acids and N-substituted acrylamides, among others. However, there are some drawbacks in the properties of hydrogels; for example, natural hydrogels lack the mechanical properties required for the application site. In addition, they can cause side effects when introduced into the human body. In contrast, synthetic polymer hydrogels can be tailored to produce useful mechanical properties among other favorable characteristics, even though there is not a perfect formula. Thus, there is an open field to improve the structures of the most popular hydrogels, which enables multiple combinations that have resulted in materials that satisfy with multipurpose characteristics, among which those with medical aims are the most relevant.
