Nanomedicines for Receptor-Mediated Tumor Targeting

Nanomedicines have been studied for a variety of medical applications, including drug delivery, molecular imaging, biosensor applications, and combined therapy and diagnostics (theranostics). In particular, therapeutic agentloaded nanomedicines have emerged as next-generation medicines for achieving improved therapeutic indexes for cancer treatment. A series of clinical studies have substantiated the potential of nanoparticle-based therapeutics for modulating in vivo fate, demonstrating enhanced tumor accumulation of delivered therapeutics. Although most commercialized nanomedicines have been based on a passive-targeting strategy that exploits the enhanced permeability and retention effect, there is an increasing need for the development of active-targeting technologies. In this context, active-targeting approaches involving the introduction of specific targeting moieties on the surface of nanoparticles to reinforce tumorlocalization and reduce side effects have received considerable recent attention. The leading strategy has been the conjugation of ligand molecules that specifically bind to receptors that are overexpressed on tumor cells relative to normal cells. Lipids and polymer-based nanoparticles have been used as drug-carrying nanomedicines. The receptors used for targeted delivery of nanomedicines include folate receptors, transferrin receptors, asialoglycoprotein receptors, integrin, CD44, and others. In this review, we introduce the various patented strategies for receptor-mediated, targeted delivery of nanomedicines.