Skip to Main content Skip to Navigation
Theses

Hydrogenated nanodiamond as radiosensitizer : chemical and physical investigations of the involved mechanisms

Abstract : Among all nanocarbons, detonation nanodiamonds (NDs) possess outstanding chemical and physical properties suitable for bio-applications. Well-controlled mass production provides NDs with a primary size of 5 nm made of a diamond-core and a shell-coating containing various surface terminations. Surface chemistry of NDs can be tuned via thermal or plasma treatments providing either positively or negatively charged NDs in water suspension. Our group recently showed that plasma hydrogenated NDs (H-NDs) behave a radiosensitizing effect on radioresistant cancer cell lines providing potential therapeutic abilities as radiosensitizing agents. Nevertheless, the mechanisms involved behind this effect are not currently well understood. The main goal of this PhD is to study the behaviour of NDs suspended in water under ionizing radiations (X-ray and Gamma) and to investigate the production of reactive oxygen species (ROS), in particular hydroxyl radicals (HO). Additional experiments allow to detect also produced solvated electrons (eaq). The detection of HO radicals and solvated electrons was realized in the presence of a fluorescence probe, the 7 OH-coumarin, under various atmospheres (air and N2O/O2). Starting from the same source of NDs, different surface chemistries were compared (oxidized, hydrogenated and surface graphitized). In parallel, colloidal properties and stability of these modified NDs in water with respect to their surface chemistry were investigated at short and long term. An overproduction of HO was observed for H-NDs for both hydrogenation methods and vacuum annealed NDs at 750°C. In addition, the production of solvated electrons was confirmed for H-NDs. These results were discussed taking into account the surface chemistry, the colloidal stability and specific interactions of water molecules with NDs.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-01744183
Contributor : Abes Star :  Contact
Submitted on : Tuesday, March 27, 2018 - 11:10:09 AM
Last modification on : Wednesday, October 14, 2020 - 4:10:36 AM
Long-term archiving on: : Thursday, September 13, 2018 - 7:49:33 AM

File

2018-03-22_MAGDALENA_KURZYP_Ph...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01744183, version 1

Collections

STAR | CEA

Citation

Magdalena Kurzyp. Hydrogenated nanodiamond as radiosensitizer : chemical and physical investigations of the involved mechanisms. Other. Université Paris Saclay (COmUE), 2017. English. ⟨NNT : 2017SACLN060⟩. ⟨tel-01744183⟩

Share

Metrics

Record views

319

Files downloads

756