Menon JU., Song L., Falzone N., Vallis KA.
© 2017 by Taylor & Francis Group, LLC. Research into the use of nanotechnology for drug delivery and imaging has witnessed remarkable growth in recent years. A major challenge is the design of nanomedicines that are specifically taken up by the cells being targeted while minimizing the toxicity that may result from the release of encapsulated therapeutics in the proximity of healthy cells. Targeting of diseased cells can be achieved by surface modification of nanomaterials using molecules such as antibodies, antibody fragments, aptamers and peptides, that specifically bind disease-associated receptors or antigens (Gu et al. 2007). In the case of cancer drug delivery, nanoparticle targeting occurs through passive accumulation via the enhanced permeability and retention (EPR) effect in tumor tissue. Accumulation in the tumor is also achieved by active targeting when small molecule ligands such as folate (Lee and Low 1995) or transferrin (Suzuki et al. 1997), peptides such as Asn-Gly-Arg (NGR) (Pastorino et al. 2003) or antibodies (Torchilin 2008; Vingerhoeds et al. 1994) are attached to the surface of nanoparticles (Fig. 5.1).