With the evolution of the “omics” era, our molecular understanding of cancer has exponentially increased, leading to the development
of the concept of personalized medicine. Nanoparticle technology has emerged as a way to combine cancer specific targeting
with multifunctionality, such as imaging and therapy, leading to advantages over conventional small molecule based approaches. In this
review, we discuss the targeting mechanisms of nanoparticles, which can be passive or active. The latter utilizes small molecules, aptamers,
peptides, and antibodies as targeting moieties incorporated into the nanoparticle surface to deliver personalized therapy to patients.