A novel hydrogel membrane composed of polyion complex gels was developed to transfer cultured cell sheets from thermoresponsive cell culture dishes. Polyion complexes have been prepared by mixing poly(N,N-dimethylacrylamide-co-2-acrylamido-2-methylpropane sulfonic acid) (P(DMAAm-co-AMPS)) as anionic water-soluble polymers and poly(N,N-dimethylacrylamide-co-2-acryloxyethyltrimethylammonium chloride) (P(DMAAm-co-AETA-Cl)) as cationic water-soluble polymers. Various polyion complexes have been prepared by changing the composition of two polyelectrolytes. Through a set of Teflon (R) ring device, polyion complexes have been modified on porous membranes by electron beams irradiated cross-linking and covalent grafting technique. NIH/3T3 mouse cells as demo cells have been cultured to prepare cell sheets. This cell sheets could be recovered by using the resulting polyion complex gels as cell sheet carriers from temperature-responsive cell culture surfaces and be transferred to new collagen-coated tissue culture polystyrene dishes. This new technique has potential applications not only for transplantation but for creation of three dimensional layered cell sheet tissues. (c) 2007 Elsevier Ltd. All rights reserved.