Most nanoparticles' parameters affect their interactions with cells. To date, all the parameters studied are basically static (e.g., size, shape, ligands, and charge). This is unfortunate, because proteins have struc-tural dynamics that most nanoparticles do not possess. Here, we study single-chain polymeric nanoparticles (SCPNs), whose structures un-dergo dynamic changes. We produced multiple sets of particles from identical polymer chains via a supramolecular reshuffling approach that allowed iterative reshuffling between a compact/static and a sparse/dynamic form. These particles are topological isomers because they have identical molecular formulas differing in connectivity and thus structural dynamics. We show that cell uptake discriminates be-tween these SCPN topological isomers. Through different endocytic pathways, the sparse/dynamic isomers are uptaken more, but the compact/static isomers access the cytosol more efficiently, as evi-denced by a glucocorticoid translocation assay. These results highlight the importance of structural dynamics' role in cellular interactions.