ABSTRACT
Nanoparticles may be targeted to the growing vasculature serving the growing cancer or to the cancer cells themselves. This chapter reviews work on targeting to the two most promising targets for cancer: angiogenesis and folate receptors. It describes other potential targets for cancer imaging and therapy with nanoparticles, including antibodies strategies using biotin. The most effective polymer used as a coating on nanoparticles to avoid detection by the reticuloendothelial system is poly(ethylene glycol). The nanoparticles targeted to the neovasculature within the tumor with no expression elsewhere in the mice as detected by luciferase expression. Nanoparticles of temperature-responsive hydrogels conjugated to folic acid have also been studied with the purpose of delivering chemotherapeutic agents. The use of folate-targeted nanoparticles for gene delivery has also been studied. A possible limitation of folate targeting is the noted variability of folate receptors expression levels not only between patients, but also within a single tumor.
