Use of epidermal growth factor receptor antibody-gold cluster conjugates with good renal excretion in targeted cancer radiation treatment.

Ultra-small gold clusters have been shown to have great potential in biomedical applications; however, it is crucial that the targeting clusters can be rapidly excreted from the body. We prepared epidermal growth factor receptor (EGFR) antibody-gold cluster conjugates with tumour-specific targeting, which also enhanced the effects of therapeutic radiation and had good renal clearance properties. We systematically investigated the effects of these clusters on targeted radiation treatment, renal clearance and toxicity over a period of 25 days in mice. The as-prepared EGFR antibody-gold cluster conjugates showed higher in vitro uptakes than gold clusters alone in treated HeLa cells and resulted in enhanced cancer radiation treatment compared with non-specific gold clusters. The in vivo treatment and improved tumour uptake showed that the EGFR antibody-gold cluster conjugates could result in higher tumour uptake and higher tumour ablation. The EGFR antibody-gold cluster conjugates showed 43% excretion in urine after 24 h, only slightly lower than that of the pure gold clusters (52%). Haematological and biochemical studies showed that the conjugates did not cause liver or kidney toxicity 30 days after injection. Therefore, the use of targeting EGFR antibody-gold cluster conjugates with low toxicities and good renal excretion can enhance radiation treatment and is promising in a number of medical applications.