Stimuli-responsive bioconjugated hydrogels that can respond to a target antigen (antigen-responsive hydrogels) were prepared by introducing antigen-antibody bindings as reversible crosslinks into the gel networks. The preparation conditions of the antigen-responsive hydrogels and the mechanism of the antigen-responsive behavior were investigated, focusing on bioconjugated hydrogel structures. This article also focuses on the effect of semi-interpenetrating polymer network (semi-IPN) structures on the antigen-responsive swelling/shrinking behavior of bioconjugated hydrogels with antigen-antibody bindings. The preparation conditions and the network structures of the bioconjugated hydrogels are discussed in relation to designing antigen-responsive hydrogels. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2144-2157, 2009