Gene silencing.

This article deals with cyclodextrin (CD) based functional rotaxanes and polyrotaxanes for drug delivery. First, we present an overview of polyrotaxane preparations for biomaterials applications. Then we bring to light the studies and strategies implied for augmented drug delivery using CD-based polyrotaxanes. The concept for enhancing multivalent interaction of a ligand-mobile polyrotaxane with receptor proteins; which is significantly related to receptor-mediated drug delivery and the efficiency of ligand-conjugated polyrotaxanes is also demonstrated in the design of inhibitors which are recognized by intestinal transporters in mammalian tissues but neither absorbed into the tissue nor exhibiting any toxicity. This concept is of more practical applications, the studies on cytocleavable polyrotaxanes for gene delivery is the modern therapy. The dynamic motion of polyrotaxanes would contribute significantly to forming a polyplex with DNA to be delivered into target cells. Moreover, dissociating the polyrotaxane structure in intracellular environments is an effective way to release DNA for transfection at the nucleus. Furthermore, polyrotaxanes are also useful in manifestation of Niemann-pick type C disease. In present article, efforts have been taken with the intention to get thorough information of polyrotaxanes conjugation with drug/ligands along with a comprehensive review of diverse approaches adopted for drug delivery till date.