Radioactive Gold Nanoparticle in Nanomedicine: Green Nanotechnology and Radiochemical Approaches. Prof. Kattesh V. Katti (Director, Institute of Green Nanotechnology, University of Missouri Cancer Nanotechnology Platform, Missouri, USA)

Radioactive nanoparticles with diagnostic and therapeutic capabilities provide intelligent drug delivery systems to maximize therapeutic activity and to minimize undesirable side-effects. One particularly attractive feature of radioactive gold nanoparticles is that it does not have to be incorporated into every tumor cell to have a therapeutic effect. The path length of the emitted radiation is sufficient to allow effective therapy following uptake into a subpopulation of tumor cells. It is this feature that has attracted recent attention to apply nanotechnology for the effective delivery of therapeutic doses of beta emitting nanoparticles selectively to tumor tissue and tumor cells. For example, the therapeutic efficacy data for GA-198AuNP corroborate their ability to induce tumor staticity because tumors harvested from the treatment group consisted largely of necrotic tissue, indicating extensive tumor cell kill. In our continued efforts to apply Green Nanotechnology for the development of therapeutic radioactive gold nanoparticles, recently we have discovered that the high antioxidant capacity of Epigallocatechin gallate (EGCG), which is the most abundant catechin polyphenol in tea, can be used to convert radioactive Gold-198 precursor to the corresponding biocompatible radioactive gold nanoparticles functionalized with Laminin receptor specific EGCG. Laminin
receptors are overexpressed in a large number of human tumors and the high in vivo affinity of EGCG toward Laminin receptors has allowed to develop Laminin receptor specific radioactive
gold nanoparticles to achieve tumor specificity (14). This lecture will provide: (a) scope and prospects of beta emitting radioisotopes in nanomedicine; (b) details on the intervention of
nuclear activation analysis and various radioanalytical approaches for the production of tumor specific radioactive gold-198 nanoparticles; and (c) full in vivo investigations on therapeutic properties of EGCG-198-AuNP agent in treating prostate tumors and (d) the overall implications of Green Nanotechnology of therapeutic beta emitting nanoparticles in oncology.