Background: Smart stimulus-responsive nanocarriers represent a rapidly growing
class of drug-delivery systems for cancer and other diseases.
Objective: The alterations of redox potential between the intracellular environment and the
extracellular space have been widely utilized as a trigger for delivery of therapeutic agents
by smart stimulus-responsive nanocarriers. We set out to review the scientific literature.
Method: Published papers between 1980 and the present day were surveyed.
Results: The advantages of redox-activated smart delivery of drugs, genes, and imaging
agents include: the amplitude of the redox-responsive signal; the simple chemical features
needed to trigger the activation process; and the relative simplicity of preparing these nanocarriers
with an integrated redox-sensitive triggering element. Redox-sensitive nanovehicles are often sensitive to
glutathione (GSH) as a regulator of cellular redox potential, which is a very important redox couple in mammalian
cells. Other nanostructures can be designed to respond to oxidation, which may be useful for drug-delivery to
sites with oxidative stress.
Conclusion: Redox-responsive nanocarriers are a prominent member of the class of smart nanocarriers, and are
expected to grow importance in coming years.