Effect of core nanostructure on the thermo-mechanical properties of soft nanoparticles

The mechanical properties of nanoparticles, especially those designed for biomedical purposes, have a large impact on their performance and have been scarcely studied. Thermoresponsive polymer-based nanoparticles are increasingly being used in biomedical applications, therefore, it is crucial to determine their thermo-mechanical response in the regime beyond their volume phase transition temperature (VPTT). The morphological characterization and comparison of thermoresponsive nano-gels (NGs), silica core nanogels (SiO2@NGs), and nanocapsules (NCs) in liquids, both below and above the VPTT, are explored in this study. We employed atomic force microscopy in Peak Force QNM mode, as well as by dynamic light scat-tering, nanoparticle tracking analysis and cryogenic electron microscopy (cryo-TEM). Surprisingly, nanocapsules presented increased resistance to deformation, when compared to nanogels, above the VPTT. This was attributed to differences in the cross-link density radial distribution between nanogels an...