A new method has been developed to produce a drug delivery system (DDS) for proteins and peptides. Employing a water-in-water emulsion technique with polyethylenglycol and hydroxyethylstarch substituted by hydroxyethylmethacrylate and a subsequent photopolymerization, microspheres can be produced. This process can be carried out with proteins present in the cross-linkable phase and without the need of any organic solvents. The hydrogel microparticles are promising to fulfil the requirements for a DDS regarding biocompatibility and biodegradability.