Fig. 4.

Cell specific targeting. The presence of specific receptors or overexpression of certain receptors on the cell surface may be explored to promote a targeted delivery of the NPs to such cells. NPs formulated with a specific targeting ligand are unable to enter cells lacking the specific receptor for the targeting ligand as illustrated by the purple cell. On the other hand, the NPs are able to specifically deliver its cargo to the cells expressing the receptor specific for the targeting ligand, illustrated by the gray cell