ABSTRACT
Cellulose is the most abundant naturally occurring polymer of glucose and is usually found as the main constituent of plants and natural fibers. The fundamental unit of cellulose is the microfibril, which are bonded in a special manner, forming a crystalline array. Cellulose derivatives constitute a large class of biopolymers with diverse physicochemical properties and large functional versatility in pharmaceutical application. Cellulose derivatives have been used as drug formulation adjuvants and, recently, microbial cellulose has been shown to be effective in tissue engineering and as a wound-healing device. By modifying the naturally occurring inexpensive renewable resources, both durable and environmentally acceptable materials can be developed. An increasing availability of biodegradable cellulose-based biopolymers will allow many users to choose them on the basis of their user-friendliness. This entry surveys the design and the applications of cellulose-based biopolymers in formulation and delivery of bioactive compounds. These biopolymers have been extensively investigated due to the large availability of cellulose in nature, the intrinsic degradability of cellulose, and the smart behavior possessed by some of the cellulose derivatives in response to physiologically relevant variables such as pH, ionic strength, and temperature.
