Synthesis and Biodistribution Study of Biocompatible 198Au Nanoparticles by use of Arabinoxylan as Reducing and Stabilizing Agent

Abstract

Radioactive gold-198 is a useful diagnostic and therapeutic agent. Gold in the form of nanoparticles possesses even more exciting properties. This work aimed at arabinoxylan-mediated synthesis and biodistribution study of radioactive gold nanoparticles (198AuNPs). The particles were synthesized by mixing suspension of arabinoxylan with H198AuCl4 without use of any additional reducing and stabilizing agents. An aqueous suspension of arabinoxylan was added to a H198AuCl4 solution, which resulted in reduction of Au3+ to 198AuNPs. Biodistribution was studied in vitro and in rabbit. The particles having exceptional stability were readily formed. Highest radioactivity was recorded in spleen after 3 h followed by liver, heart, kidney and lungs after i.v. administration. After 24 h the activity was not detectable in spleen; it accumulated in liver. However, after oral administration the activity mainly accumulated in colon. In serum proteins the distribution was: α1-globulin 6.5%, α2-globulin ~2%, β- globulin ~1%, γ-globulin 0.7% and albumin 0.7% of the administered dose. This indicates a low protein binding implying high bioavailability of the particles. The cytotoxicity study showed that the particles were inactive against HeLa cell line and A. tumefaciens. Highly stable 198AuNPs reported in this work have potential for targeting colon. They show affinity for globulins, the property that can used in study of immune system.