Hydrogels based on cellulose nanocomposites

Hydrogels are three-dimensional (3D) network structures containing water. Hydrogels are promising materials for various science fields. Hydrogels can be produced from numerous synthetic and organic polymer matrices. The synthesis of hydrogels from natural biomaterials is interesting because of renewability, biodegradability, eco-friendly, and abundant properties. Among these natural polymers, cellulose is a favorable carbohydrate polymer due to being abundant in nature. Its excellent surface structure possesses a high amount of OH groups allowing surface modifications. Besides native cellulose, its forms in nanodimension scales are remarkable and significant for hydrogel synthesis. Cellulose nanofibrils and cellulose nanocrystals are nanosized cellulose mostly preferred as reinforcement in the hydrogel process because of their flexibility, biocompatibility, surface-modification facility, and mechanical stability characteristics. Hydrogels, including these types of nanomaterials, are also classified as nanocomposites. In this chapter, cellulose types, especially those based on plant-based nanocellulose and their fundamental modifications, are examined. Then their utilization in a hydrogel, mainly in drug delivery and tissue engineering, is deeply researched.