Targeted nanoparticles for tumour radiotherapy enhancement—the long dawn of a golden era?

Abstract

Despite considerable progress in (I) our understanding of the aetiopathology of head and neck cancer and (II) the precise delivery of radiotherapy, long-term survival rates for many patients with head and neck cancer remain disappointingly low. Over the past years, gold nanoparticles (NP) have emerged as promising radiation dose enhancers. In a recent study published in Nanoscale, Popovtzer et al. have used gold NP coated with an antibody against the epidermal growth factor receptor (EGFR) in an attempt to enhance radiation-induced tumour cell killing in a head and neck cancer xenograft model. They report a significant impact of the combined treatment with radiation and gold NP on tumour growth and suggest an involvement of apoptosis, inhibition of angiogenesis and diminished tissue repair. In this perspective, we illustrate the underlying radiobiophysical concepts and discuss some of the challenges associated with this and related nanoparticle-radiotherapy studies from a physics, chemistry, biology and therapy angle. We conclude that strong interdisciplinary collaborations spanning all these areas are crucially important to proceed towards effective cancer treatment with gold NP "from bench to bedside".

Radiosensitization of Prostate Cancers In Vitro and In Vivo to Erbium-filtered Orthovoltage X-rays Using Actively Targeted Gold Nanoparticles

“…Consistent with previous work using GNPs as radiosensitizers, our results demonstrate that conjugation of GNPs to active targeting moieties results in increased tumor cell uptake and subsequent radiosensitization compared with unconjugated GNP controls 8 , 28 – 30 . While unconjugated GNPs rely exclusively on leaky tumor vasculature to reach tumors by the EPR effect, it is clear that tumor-targeted GNPs accumulate to a higher degree within tumor cells, representing an elegant advancement in nanomedicine with promising broad clinical applications.…”

Chemical Mechanisms of Nanoparticle Radiosensitization and Radioprotection: A Review of Structure-Function Relationships Influencing Reactive Oxygen Species

“…This decrease of glutathione minimized the antioxidant properties of the cancer cell and radiosensitization occurred [118]. Additionally, silver nanoparticles coated with polyvinylpyrrolidone have shown an affinity to bind and reduce thiol antioxidants within the cellular environment, including glutathione [100,158].…”

“…These examples of literature highlight the importance of surface properties not only with respect to stability and cell uptake, but also their synergistic or antagonistic influence on mechanistic action [158].…”

Using gold nanoparticles in diagnosis and treatment of melanoma cancer

“…As previously pointed out, for selecting delivery of AuNP into tumour cells, its conjugation with PEG (named passive delivery) or with antibodies or even hormones to certain tumour-related proteins (named active delivery) is considered as a delivery strategy [69]. By using PEG, AuNP can be stabilized in blood circulation because of its special characteristics, including low lymphatic drainage and low exposing to immune cells [70].…”