Poly(ethylene glycol)s are cross-linked by tris(6-isocyanatohexyl)isocyanurate via urethane/allophanate bond formation to obtain polymeric networks capable of swelling in phosphate-buffered saline or ethanol, resulting in gels. The protein loading of the gels swollen in ethanol is enhanced by formation of hydrophobic ion-paired complexes of proteins with sodium dodecyl sulfate. The protein release profile from loaded gels through biomimetic membranes impregnated with phosphatidylcholine is governed by the gel crosslinking density. Spectroscopic data and enzymatic activity of the proteins released from the gels into aqueous solutions indicate that proteins are recovered unchanged upon their redissolution in water.