In this work, the elasticity under stretching as well as fluidity of Giant Hybrid Unilamellar Vesicles (GHUV) has been studied. The membrane structuration of these GHUVs has been already studied at micro and nanoscale in a previous study of the team1. These GHUVs were obtained by the association of fluid phospholipid (POPC) and triblock copolymer poly(ethyleneoxide)-b-poly(dimethylsiloxane)-b-poly(ethyleneoxide). Although triblock copolymers’ architecture can facilitate vesicle formation , they have been scarcely used to generate GHUVs. We show, through micropipette aspiration and FRAP experiments, that the incorporation of a low amount of lipids in the polymer membrane leads to a significant loss of the toughness of the vesicle and subtle modification of lateral diffusion of polymer chains. We discuss the results within the framework of conformation of the triblock copolymer chain in the membrane, and of the presence of lipid nanodomains.