(a) Confocal microscopy of Cy5-mRNA treated HeLa cells stained with (TRITC)-Dextran4400 endosomal marker showing escape for D13:A11 CART system and colocalization for non-self-immolative control D13:G12 system, scale: 10 μm (reproduced with permission from reference 60, Copyright 2017 The National Academy of Sciences of the USA); (b) HUVEC cells transfected with Cy5-pDNA through pAsp(DET) and pAsp(EDA-Suc) polyplexes showing efficient endosomal escape after 24 h for only pAsp(DET) polyplexes, endosome/lysosomes were stained with Lysotracker green, scale: 20 μm (reproduced with permission from reference 83, Copyright 2008 Wiley-VCH Verlag GmbH & Co.); (c) top: Endosomal colocalization (after 4 h) and escape (after 24 h) of cy3-siRNA delivered via L-siP nanoassembly, endosome stained with Lysotracker blue (pseudo-colored as green), scale: 20 μm; bottom: Calcein assay showing release of calcein dye from endosomes to cytosol only in presence of L-siP nanoassembly, while calcein remain entrapped for control cells, scale: 10 μm (reproduced with permission from reference 53, Copyright 2019 American Chemical Society).