Cancer nanotheranostics: A review of the role of conjugated ligands for overexpressed receptors

Cancer treatment using chemotherapy has many drawbacks because of its non-specificity, in which the chemotherapeutic agent attacks both normal and cancerous cells, leading to severe damage to the normal cells, especially rapidly proliferating ones. Cancer targeting enables the drug to kill only tumor cells without adversely affecting healthy tissues, which leads to the improvement of the patient's well-being. Nanoparticles offer several advantages in drug delivery such as enhancing the solubility of hydrophobic drugs, sustaining their release and prolonging their circulation time. The ability of nanoparticles to specifically target tumor cells makes them a useful delivery system for anticancer agents. The type of the delivery system and formulation additives used can also improve the delivery of the anticancer agent. This review highlights some of the most highly sought receptors to be targeted in selective cancer treatment. It also reports some of the recent advances in cancer targeting using drug-loaded ligand-conjugated nanocarriers.