Figure 2.

Schematics of nanoparticle delivery using liposomes-only and virus-based liposomes. A. Intracellular delivery of Qdots functionalized with biotinylated antibodies for iEFGR by using liposomes-only. Liposomes containing functionalized Qdots are incubated with the cells (A1). The liposomes are internalized via endocytosis by the cells (A2). Liposomes are internalized within cell endosomes, trapping the functionalized Qdots (A3); B. Intracellular delivery of Qdots functionalized with biotinylated antibodies for iEFGR by using virus-based liposomes (VBLs). VBLs containing functionalized Qdots are incubated with the cells (B1). VBLs fuse with the plasma membrane to release Qdots into the cytosol (B2). The functionalized Qdots bind to their intracellular targets on the EGFR (B3). C. Preparation of VBLs: Sendai viruses (1) were inactivated by exposure to UV light (2) (for details see Methods). A TEM insert illustrates an inactivated virus of ~ 200 nm diameter. Liposomes containing targeted Qdots (4) were prepared as described in Methods by incorporating Qdots functionalized with anti-iEGFR antibodies into lipidic membranes (3). A TEM insert illustrates a ~100 nm diameter liposome containing functionalized Qdots. Next, the liposomes were fused with the inactivated viruses, to give rise to VBLs (5). A TEM insert illustrates the fusion products.