“…While passively targeted drug delivery to tumor cells can be achieved by exploiting the enhanced permeability and retention (EPR) effect, , nanocarriers with targeting functionalities offer a versatile way to deliver cargo to a specific cell type expressing the corresponding receptors. Targeting can be mediated by either nanoparticle size or ligands for selective recognition such as antibodies, , folic acid, , biotin, , peptides, , hormones, , and carbohydrates …”