SEM analysis of surface-treated dialdehydestarch.
Surface characteristics of protein-treated dialdehydestarch (DAS), which is utilizable as a gastrointestinal sorbent for the treatment of uremia, are examined by scanning electron microscopy (SEM). Unique wrinkles or continuous depressions were observed on the surface of some albumin-treated DAS particles. An increase in concentration and composition of albumin to DAS produces more particles with this kind of rugged surface. On the other hand, gelatin treatment provided a DAS with somewhat rough surface. As the stoichiometric ratio of gelatin to DAS increases, some fibrous or thin-leaves-like projections became outstanding on the surface. Urea-binding properties of protein-treated DAS are just about the same regardless of the protein concentration or composition. In addition, wrinkles or depressions partly observed on the surface of albumin-treated DAS are of little benefit in terms of effective urea binding. These results mean that inherent physical properties of DAS such as dialdehyde content would be a critical factor in urea-sorption ability, rather than surface characteristic or the presence of protein.