ABSTRACT
This chapter provides a comprehensive overview of synthetic ways to improve the physical-chemical properties of alginate hydrogels in relation to their biomedical applications as alginate carriers in delivery systems. Alginate is an anionic and linear polysaccharide of natural origin obtained from brown seaweeds such as Laminaria hyperborea, Macrocystis pyrifera, and Ascophyllum nodosum. The formation of networks for alginate delivery systems through non-covalent bonds involves synthetic strategies including ionic interaction and interpenetrating polymer networks. The chemical modification of alginate furnishes it with different functionalities, thus expanding the number of potential applications and improving its mechanical properties in delivery systems. The objective of alginate covalent cross-linking is an improvement in physical properties, making a material not easily influenced by environmental variables such as pH, ionic strength, temperature, and so forth. A different strategy to produce a controlled delivery device is layer-by-layer microcapsule formation by a combination of alginate and chitosan.
