Interpenetrating polymer networks (IPNs) based on poly (N-isopropylacrylamide), PNIPAAm, and poly (N-acryloxysuccinimide), PNAS, were prepared by a sequential method; the PNIPAAm which was polymerized and crosslinked by gamma irradiation, was swelled in a solution of PNAS/polylysine, which function as crosslinking agent for this monomer and as anchoring element of vesicles. The thermosensitivity properties (limit swelling time, lower critical solution temperature (LCST) and water retention), chemical composition (FTIR and elemental analysis), thermal properties (DSC and TGA) and morphology (SEM) were studied to characterize the IPNs.