Development and characterization of cellulose based hydrogels for use as dietary bulking agents

In the last decade cellulose-based hydrogels have been receiving increasing attention for a number of applications, due to their smart swelling behaviour, biodegradability and biocompatibility. Given the dramatic spreading of obesity and overweight in the industrialized countries and the lack of scientific consensus over currently available dietary supplements, it was recently proposed that such hydrogels might be used as orally administered bulking agents in hypocaloric diets, since the hydrogel swelling in the stomach may greatly reduce the space available for food intake, thus giving a sense of fullness. This study focused on the synthesis of cellulose-based hydrogels, starting from pharmaceutical and food grade cellulose derivatives, and showed that such hydrogels possess good swelling properties in water solutions mimicking the environmental conditions of the stomach and the intestine, as well as a good biocompatibility. The crosslinking agent used was a ‘zero-length’ crosslinker, i.e. a water soluble carbodiimide, which is washed out from the gel after the synthesis and does not affect the gel compatibility, as shown by preliminary biocompatibility assays. The experimental results confirmed that cellulosebased hydrogels might be a scientifically valid dietary adjuvant in the treatment of obesity and overweight, and provide further scientific evidence for future experiments on humans.