Ultrasmall Glutathione-Protected Gold Nanoclusters as Next Generation Radiotherapy Sensitizers with High Tumor Uptake and High Renal Clearance

TL;DR

This study introduces ultrasmall glutathione-protected gold nanoclusters as effective, kidney-clearable radiosensitizers that enhance tumor radiotherapy while minimizing damage to healthy tissues.

Contribution

The paper presents a novel design of ultrasmall GSH-coated gold nanoclusters that improve tumor uptake and clearance, offering a safer and more effective radiosensitizer for cancer treatment.

Findings

High tumor uptake of 8.1% ID/g at 24h post injection.

Significant enhancement of radiotherapy efficacy.

Negligible damage to normal tissues and efficient renal clearance.

Abstract

Radiotherapy is often the most straightforward first line cancer treatment for solid tumors. While it is highly effective against tumors, there is also collateral damage to healthy proximal tissues especially with high doses. The use of radiosensitizers is an effective way to boost the killing efficacy of radiotherapy against the tumor while drastically limiting the received dose and reducing the possible damage to normal tissues. Here, we report the design and application of a good radiosensitizer by using ultrasmall gold nanoclusters with a naturally occurring peptide (e.g., glutathione or GSH) as the protecting shell. The GSH coated gold nanoclusters can escape the RES absorption, leading to a good tumor uptake (8.1% ID/g at 24 h post injection). As a result, the as-designed Au nanoclusters led to a strong enhancement for radiotherapy, as well as a negligible damage to normal tissues. After the treatment, the ultrasmall gold nanoclusters can be efficiently cleared by the kidney, thereby avoiding potential long term side effects caused by the accumulation of gold atoms in the body. Our data suggest that the ultrasmall peptide protected Au nanoclusters are a promising radiosensitizer for cancer radiotherapy.