the present invention relates to swellable polymeric materials comprising a synthetic polymer , or copolymer , comprising a carboxylic group and a biopolymer that are suitable for bioapplications . because of their ability to swell , the polymeric materials are suitable for use as stomach fillers for the treatment of being over weight or obese , or for inducing the feeling of being satiated . methods for preparing the swellable polymeric materials comprising aqueous reaction systems are also disclosed .