Abstract
A new approach for the treatment of solid tumor cancers that utilizes aspects of bionanotechnology to deposit a short‐lived radioisotope throughout the tumor mass is described. Selectively Targeted Amplified Radiotherapy (STAR) is a multi‐step therapy in which an insoluble nano‐platform is first built inside neoplastic cells from a soluble precursor. The nano‐platform is then released into the extra‐cellular space throughout the tumor by disruption of some of the neoplastic cells. The nano‐platform is constructed so that it can selectively attach a reagent incorporating an exogenous enzyme, thereby transforming the insoluble nano‐platform into a nano‐factory. Finally, the enzymatic activity of the nano‐factory is used to convert a soluble radioactive substrate into a water‐insoluble nano‐precipitate throughout the tumor. The remaining soluble radiochemical is cleared from the body while the radioactive nano‐precipitate remains throughout the tumor, irradiating the surrounding tumor cells and providing what can be called molecular brachytherapy. This report discusses how the STAR technology overcomes tumor heterogeneity and metastases, the two major obstacles to successful treatment of solid tumor cancers. Drug Dev. Res. 67:94–106, 2006. © 2006 Wiley‐Liss, Inc.