ABSTRACT
Biotechnology has a unique position in prodrug therapy. Progress in gene cloning and meticulous methods of gene expression in mammalian cells have permitted explication of molecular characteristics of carrier proteins and enzymes, thereby providing a more coherent approach of targeted prodrugs. The targeted enzyme facilitates conversion of nontoxic prodrug into an active therapeutic entity, capable of killing agent within tumor cells. Gene-directed enzyme-prodrug therapy is an exclusive and successful prodrug delivery approach that has received unique position in cancer therapy. The prodrug administered is then converted into cytotoxic therapeutic molecule at the tumor site under the influence of expressed enzyme resulting tumor-selective cytotoxicity. Virus-directed enzyme-prodrug therapy approach that exploits viral vectors to transport a gene encoding certain enzyme proficient to convert prodrug into active therapeutic entity. Prodrugs directed towards membrane transporters present on the surface of epithelial cell on are possibly the most exhilarating existing drug delivery strategies.
