Highly Swellable Hydrogel from Neutral Hydroxyethyl Cellulose for Human Weight Control

Highly swellable hydrogels from biopolymers have great application potential as medicines for weight control. However, the limited swelling ratio of neutral biopolymers restrains their application in weight control medicines. In this work, we developed a highly swellable hydrogel from hydroxyethyl cellulose/citric acid (HEC/CA) by a simple "drying–swelling" strategy. The CA attached to the HEC provided the HEC with improved hydrophilicity. By carefully controlling the CA/HEC ratio, the maximum swelling ratio of the gel reached up to 200 at body temperature, and the water content of the swollen hydrogel can reach 99.5%. The HEC/CA hydrogel presented suitable swelling–dissolving properties in a buffer solution with pH values similar to those during digestion. The high swelling ratio and the swelling–dissolving behavior provide the gel with great potential to be applied as a safe medicine for weight control.