Cellulose is a naturally occurring, linear polysaccharide used in a wide range of industrial and consumer product applications including as a chief ingredient in paper and textile manufacturing, as a biofuel, and as a thickening agent and stabilizer in food products. The semi-permeability of the polymer lends itself to function well as a filter; therefore, modified cellulose materials often are utilized in the biomedical industry in dialysis tubing to treat kidney disease.
Dialysis tubing membranes are differentiated by their molecular weight cutoffs (MWCOs). MWCO is a parameter related to the number of pores and the average pore size, which can be controlled by the cellulose chain length and by the degree of cross-linking. The MWCO of a material will dictate what size of molecules will or will not pass through and thus determines the effectiveness of the membrane in removing waste products from a patient’s bloodstream. Characterizing pore size and topography will be essential to design bio-membranes with ideal filtering properties. Another application of modified cellulose in which topography is critical is drug delivery where pore size directly impacts drug encapsulation stability and release kinetics.