The ideal delivery system should
solubilize the drug, provide targeted therapy, exhibit no/minimum drug
toxicity, possess high bioavailability and should be capable of exhibiting
programmable release. Nanosponges are one of such novel effective drug carriers
which conquer the problems associated with conventional treatment. They are a
novel class of hyper cross-linked polymer based colloidal structures in which a
large variety of substances can be encapsulated.They
are biologically safe and simple to produce. The prominent examples of
nanosponges include Titanium based nanosponges, Silicone based nanosponges,
Hyper cross-linked polystyrene nanosponges, Cyclodextrin based nanosponges etc. Among all, Cyclodextrin
based nanosponges show remarkable encapsulation efficiency and find several
applications. They offer the possibility to incorporate small molecules, macromolecules
and gases to a great extent. Studies even
reveal that nanosponges can be formed spontaneously by mixing two trimeric
peptide building blocks, cholesterol –(K)n DEVDGC)3 and cholesterol –(D)n DEVDGC)3-trimaleimide
(n = 5,10,15,20) in aqueous buffers.
Today cancer is the second worldwide cause of death, exceeded only by
cardiovascular diseases and targeted delivery of therapeutics to the tumor site
with minimized side effects is of vital
importance in cancer therapy. As
conventional therapies fail to achieve it, drugs can be incorporated into these nanocarriers. Several reports indicate that chemo-resistant
cancer cells become highly adapted to intrinsic oxidative stress by up-regulating their antioxidant systems, which
causes an increasing intracellular GSH content.
This increases the demand for new
therapeutic strategies that are capable of reducing dose and overcoming
chemo-resistance. Glutathione responsive
Cyclodextrin Nanosponges (GSH-NS) is one such discovery that is capable of
releasing anticancer drugs preferentially in cells having high GSH content.
Several “in vitro” and “in vivo” studies are performed to compare the
anticancer effect of conventional therapies and therapies using these nanocarriers.
This review mainly focuses on use of nanosponges for anticancer therapy.