Ultra-small but ultra-effective: Folic acid-targeted gold nanoclusters for enhancement of intracranial glioma tumors' radiation therapy efficacy

Abstract

The aim of the present study is to investigate folic acid and BSA decorated gold nanoclusters (FA-AuNCs) effect on the enhancement of intracranial C6 glioma tumors radiation therapy (RT) efficacy. Inductively coupled plasma optical emission spectrometry (ICP-OES) measurements exhibited about 2.5 times more FA-AuNCs uptake by C6 cancer cells (32.8ng/10(6) cells) than the normal cells. FA-AuNCs had significantly higher concentration in the brain tumors (8.1mug/mg) in comparison with surrounding normal brain tissue (4.3mug/mg). Moreover, FA-AuNCs exhibited dose enhancement factor (DEF) of 1.6. The glioma-bearing rats' survival times were almost doubled at radiation therapy + FA-AuNCs (25.0+/-1.5days) in comparison with no-treatment group (12.8+/-0.7days). The Ki-67 labeling index was 48.89+/-9.93 for control, 29.98+/-8.32 for RT, and 11.53+/-7.65 for RT+FA-AuNCs. Therefore, FA-AuNCs can be effective radiosensitizers for intracranial glioma tumors RT.