Cellulose-Based Hydrogels as Biomaterials

Abstract

Hydrogels are three-dimensional hydrophilic network structures that vary greatly in swelling/shrinkage properties against minor changes such as light density, solvent composition, ionic strength, pH, and temperature. Cellulose-based hydrogels are derived from natural sources which are biodegradable and low-immunologic. These hydrogels are produced in four different ways: those obtained directly from native cellulose (including bacterial cellulose), those derived from cellulose derivatives (methyl cellulose, carboxymethyl cellulose, hydroxy methyl cellulose, etc.), those obtained with other polymers as a composite, and finally those obtained from cellulose-inorganic hybrids. Cellulose hydrogels and its derivatives have many desirable properties such as high water retention capacity, high crystallinity, fine fiber network, easy formability, and high tensile strength. In addition, some cellulose derivatives exhibit intelligent behavior against physiological variables such as pH and ionic strength. Cellulose-based hydrogels have advantages such as better biocompatibility, less latent toxicity, and lower cost than the most synthetic polymer hydrogels. Because of these advantages, cellulose-based hydrogels are preferred to be used in industrial pharmaceutics and biomedical fields. This chapter will discuss applications of cellulose-based hydrogels in pharmaceutical industry and biomedical fields such as drug release systems, wound healing, and tissue engineering. In addition, future prospects on cellulose-based hydrogels will be addressed.