Prostate tumor therapy advances in nuclear medicine: green nanotechnology toward the design of tumor specific radioactive gold nanoparticles

We report herein an innovative approach to prostate tumor therapy using tumor specific radioactive gold nanoparticles (¹⁹⁸Au) functionalized with Mangiferin (MGF). Production and full characterization of MGF-¹⁹⁸AuNPs are described. In vivo therapeutic efficacy of MGF-¹⁹⁸AuNPs, through intratumoral delivery, in SCID mice bearing prostate tumor xenografts are described. Singular doses of the nano-radiopharmaceutical (MGF-¹⁹⁸AuNPs) resulted in over 85% reduction of tumor volume as compared to untreated control groups. The excellent anti-tumor efficacy of MGF-¹⁹⁸AuNPs are attributed to the retention of over 90% of the injected dose within tumors for long periods of time. The retention of MGF-¹⁹⁸AuNPs is also rationalized in terms of the higher tumor metabolism of glucose which is present in the xanthanoid functionality of MGF. Limited/no lymphatic drainage of MGF-¹⁹⁸AuNPs to various non-target organs is an attractive feature presenting realistic scope for the clinical translation of MGF-¹⁹⁸AuNPs in for treating prostate cancers in human patients. The comparative analysis of MGF-¹⁹⁸AuNPs with other radioactive gold nanoparticles, functionalized either with epigallocatechin gallate or the Gum Arabic, has revealed significantly superior tumoricidal characteristics of MGF-¹⁹⁸AuNPs, thus corroborating the importance of the tumor-avid glucose motif of MGF. Oncological implications of MGF-¹⁹⁸AuNPs as a new therapeutic agent for treating prostate and various solid tumors are presented. (author)