Nanotechnology improves the efficiency of cancer radiotherapy
External radiotherapy is usually based on X or gamma rays. Fast ions in the form of carbon and protons have emerged as alternative ionising radiation since they facilitate high localisation of the radiation effects at the end of the track, in the tumor. Hence, the dose deposited behind the tumor is close to zero. However, on the path of the beam in front of the tumour, the dose deposition remains significant. It is thus necessary to improve the hadrontherapy performance by concentrating the effects of the ion radiation into the tumour cells. Towards this goal, scientists on the EU-funded NANOHAPY (Nanomedicine and Hadrontherapy) proposed the use of targeted nano-agents capable of amplifying the effects of fast ions in the tumours. In this context, they performed characterisation of metal-based nanoparticles (NPs) and investigated their interaction with cancer cells and their biological effects upon irradiation. NPs based on gold, gadolinium and platinum were generated and further tested in cancer cells for cytotoxic effects. This led to the estimation of the maximum concentration with no toxic impact on human cells. The insight into the kinetics of internalisation and expulsion unveiled important differences among several human cancer and healthy cells. Complementary microscopic technics revealed that NPs localised with unique efficiency and pattern in the cell cytoplasm. Further experiments to determine the molecular and cellular effects of NPs following ionising radiation showed decreased cell viability and division potential without any enhancement of double strand breaks in the nucleus. Collectively, the results of the NANOHAPY study demonstrate the potential of combining NPs with ionising radiation in cancer therapy. However, given the heterogeneity of NPs effects, project findings emphasise the need for further studies into the revolutionary new role of these agents in cancer radiotherapy. A clearer understanding of the molecular events rising in the cell cytoplasm upon NPs irradiation and tumour resistance is required to maximise NPs therapeutic potential.
Keywords
Cancer, radiotherapy, hadrontherapy, NANOHAPY, nanoparticles