HiSORセミナー
日時 2018年2月23日 （金） 13:00～
場所 放射光科学研究センター 2階 セミナー室
Nanoparticles: exquisite tools to improve radiation based therapies
講師 Sandrine Lacombe
(University Paris-Sud, CNRS. Orsay (France))
Radiotherapy is used to fight against cancer in about 50 % of all cancer patients. Recently, the addition of nanoparticles (NPs) has been proposed as a new strategy to enhance the effect of radiotherapy. In this presentation, a state-of-art of the current knowledge will be summarized [1,2]. The group at ISMO demonstrated that high-Z NPs amplify the effects of medical carbon ions (hadrontherapy). The underlying physical processes have been investigated [3-6]. The studies performed at molecular scale and in vitro studies with gold nanoparticles (AuNPs), platinum nanoparticles (PtNPs) [3]. and gadolinium-based nanoparticles (GdBN) [4] will be presented. We have demonstrated that hydroxyl radicals play a major role in the amplification of cell killing in the presence of NPs. In all cases the NPs are found in the cytoplasm but not in the nucleus of the cells. As evidenced by different microscopy techniques, the uptake dynamics of NPs in cells is strongly related to the cell line. Interestingly, GdBN co-localize with lysosomes whilst AuNPs are found in the proximity of mitochondria. close to cytoplasmic organelles such as lysosomes (GdBN) [6] or mitochondria (AuNPs).
As recently investigated, we observed that the effect of NPs depends mainly on the oxygen concentration in the environment (normoxic versus anoxic conditions). In conclusion, the high potentiality of high-Z nanoparticles to improve the performances of hadrontherapy and the perspectives of theranostic will be presented in this seminar.
References:
1. Zdenka Kunkic and S. Lacombe. Nanoparticle radio-enhancement: principles, progress and application 1 to cancer treatment. Phys.Med.Biol. 63 (2018)
2. S. Lacombe, E Porcel, and E. Scifoni. Particle therapy and nanomedicine: state of art and research perspectives. Cancer Nanotechnology 8:9 (2017).
3. Porcel, E., et al., Platinum nanoparticles: a promising material for future cancer therapy? Nanotechnology, 2010. 21(8): p. 7.
4. E Porcel, et al., Gadolinium based nanoparticles to improve the hadrontherapy performances. Nanomedicine : Nanotechnology, Biology, and Medicine 2014, vol 10, Issue 8, p 1601-1608
5. Porcel, E., et al. Nano-Sensitization under gamma rays and fast ion radiation J. Phys.: Conf. Ser. 373, 012006 (2012).
6. L. Štefančíková, et al., Cell localisation of gadolinium-based nanoparticles and related radiosensitising efficacy in glioblastoma cells. Cancer Nanotechnology 2014, 5:6
Radiation Damage to DNA Induced by K-shell Electron Ionizations
講師 Kentaro Fujii
(National Institutes for Quantum and Radiological Science and Technology)
Chemical bond cleavage induced by Auger process is one of the essential process to achieve the molecular scalpel by site selective bond scission, which was intensively investigated in Hiroshima university in the end of 1990’s. Auger process is also predicted as a crucial process for inducing an effective biological damage in DNA molecule, which was predicted by Platzman in 1950’s.
In order to investigate the DNA damage process induced with Auger process, we are performing spectroscopic experiments in synchrotron facility SPring-8. Recently we measured the desorbing ions from hydrated sample film to reveal the role of hydrating water molecule. Recent topics of our study using soft X-ray spectroscopic method to clarify the initial process of the ionizing radiation for inducing DNA damage would be presented in this seminar.
問合せ先 松尾光一（放射光科学研究センター）
