This article describes the preparation and characterization of mixed mesoglobules from two thermoresponsive polymers: poly(N-isopropyl acrylamide) (PNIPAM) and poly(2-isopropyl-2-oxazoline) (PIPDX) and their coating with a crosslinked shell to obtain hybrid nanoparticles. The variations in dimensions and stability of the mixed mesoglobules prepared with different compositions (20/80, 50/50 and 80/20 PIPDX-to-PNIPAM weight ratios) and using different heating protocols (gradual and abrupt heating) indicate their sensitivity to both parameters. Unlike neat PIPDX particles as well as PIPDX-rich ones, the mixed particles with higher PNIPAM content (20/80 and 50/50) exhibit a fully reversible coil-to-globule phase transition implying that in these cases PNIPAM effectively prevents the crystallization of PIPDX. The mesoglobules were covered with a cross-linked polymeric shell by seeded radical copolymerization of NIPAM and N,N-methylenbisacrylamide. The resulting hybrid nanoparticles retain their stability and do not disintegrate at low temperatures. (C) 2015 Elsevier Ltd. All rights reserved.