centered on cancer treatment,
as
targeted therapies are greatly needed in this field due to the
harsh side effects of current broad-based treatments. Through
both passive and active targeting, the concentration of drug
can be increased at the tumor site while limiting the exposure
of (and consequent toxicity to) healthy tissue.23 Stage I clinical
trials have been completed for the delivery of tumor necrosis
factor (TNF) bound to the surface of gold nanospheres.17
TNF is a potent cytokine that has shown antitumor properties
in isolation and even greater effects as part of a combined
therapy.57,58 Though the mechanism for action is complex,
results suggest that TNF is able to significantly increase the
permeability of the tumor vasculature, eventually causing
destruction of the vascular lining, and also allowing for greater
delivery of other chemotherapeutic agents.57,58 Unfortunately,
the practical dosage is limited by the severe toxicity of TNF.
However, when TNF is conjugated to gold nanospheres, the
toxicity can be greatly reduced, allowing for significantly
higher dosages of TNF to be delivered to the tumor site.