AGE precursors can be removed from blood, plasma or PBS buffer using a modified polymeric shaped body that can be produced by reaction of diaminoguanidine and/or triaminoguannidine with a staring polymeric shaped body carrying R—X residues, where R is an alkylene group that may or may not be substituted with a hydroxyl group and contains from 1 to 3 carbon atom, and X is a group that is substituted during the reaction by carrying residues Y, on to with diaminoguanidine, or with a starting polymeric shaped body during the reaction which diaminoguanidine and/or triaminoguannidine are added during the reaction.