Cellulose Nanocrystals-Based Hydrogels for Drug Delivery

Recently, cellulose nanocrystals (CNC) have gained attention from researchers around the world due to their favourable properties such as low cost, nontoxicity, biodegradability, biocompatibility, and as small, strong hydrophilic materials, which render them favourable candidates for the preparation of hydrogels. The incorporation of CNC within a hydrogel matrix enables the hydrogel to sustain its shape during swelling-deswelling. Besides absorbing and retaining large amounts of water, hydrogels also respond to specific external environmental factors, such as temperature, pH, the presence of ions, and concentration, making them appealing to be engineered for drug delivery applications. In addition, CNCs also confer high mechanical strength and thermal stability to the hydrogels, which expand their potential in biomedical applications. This chapter focuses on the synthesis of nano cellulosebased hydrogels for drug delivery applications, including the extraction of CNC from various sources, fabrication of hydrogels using chemical and radiation crosslinking, the chemical, physical, and ‘smart’ properties of the hydrogels, and their application in controlled drug delivery.