Figure 14.

(1) Schematic illustration of the optimal virus assembly on lipid bilayer-coated -LbL microparticles using the unique conformational reversibility of the VSV-G protein. Assembly strategy is shown, making use of the unfolded state of the protein at pH 4, to initiate fusion with the lipid bilayer (a). After neutralization, VSV-G regains its prefusion state, allowing the protein to be available for specific cell interaction via receptor binding (b). Reprinted with permission from reference [256] copyright © 2018 American Chemical Society. (2) Schematic illustration of the possible fusion mechanisms between the lipid-bilayer-coated LbL coated particles and the endolysosomal membrane. In the upper panel, I and II, virus protein-mediated membrane fusion with endolysosome is shown, while the lower panel (III) illustrates the membrane-membrane fusion of nonfunctionalized particles and endolysosome. Red dots represent the fluorescent label of the lipid layer, and green dots demonstrate the formation of the fusion protein. Reprinted with permission from reference [255] copyright © 2020 American Chemical Society.