Improving proton therapy by metal-containing nanoparticles: nanoscale insights

Abstract

The use of nanoparticles to enhance the effect of radiation-based cancer treatments is a growing field of study and recently, even nanoparticle-induced improvement of proton therapy performance has been investigated. Aiming at a clinical implementation of this approach, it is essential to characterize the mechanisms underlying the synergistic effects of nanoparticles combined with proton irradiation. In this study, we investigated the effect of platinum- and gadolinium-based nanoparticles on the nanoscale damage induced by a proton beam of therapeutically relevant energy (150 MeV) using plasmid DNA molecular probe. Two conditions of irradiation (0.44 and 3.6 keV/μm) were considered to mimic the beam properties at the entrance and at the end of the proton track. We demonstrate that the two metal-containing nanoparticles amplify, in particular, the induction of nanosize damages (>2 nm) which are most lethal for cells. More importantly, this effect is even more pronounced at the end of the proton track. This work gives a new insight into the underlying mechanisms on the nanoscale and indicates that the addition of metal-based nanoparticles is a promising strategy not only to increase the cell killing action of fast protons, but also to improve tumor targeting.

Keywords:

• gadolinium-based nanoparticles
• platinum nanoparticles
• nanosensitization
• theranostics

Acknowledgments

Financial support from the European Union within the COST Action MP1002 “Radiation damage in biomolecular systems: nanoscale insights into ion-beam cancer therapy” (Nano-IBCT) and for the funding of the Marie Curie fellowship Nanohapy FP7-PEOPLE-2013-IEF N°624370 is gratefully acknowledged.

Disclosure

The authors report no conflicts of interest in this work.