2018_EJRNL_PP_Marine_Le_Goas_1.pdf
Terbatas Latifa Noor
» ITB
Terbatas Latifa Noor
» ITB
In the context of cancer treatment, gold nanoparticles
(AuNPs) are considered as very promising radiosensitizers. Here, well-
de
fi
ned polymer-grafted AuNPs were synthesized and studied under
gamma irradiation to better understand the involved radiosensitizing
mechanisms. First, various water-soluble and well-de
fi
ned thiol-function-
alized homopolymers and copolymers were obtained through atom
transfer radical polymerization. They were then used as ligands in the
one-step synthesis of AuNPs, which resulted in stable hybrid metal
?
polymer nanoparticles. Second, these nano-objects were irradiated in
solution by
?
rays at di
ff
erent doses. Structures were fully characterized
through size exclusion chromatography, small-angle X-ray scattering, and
small-angle neutron scattering measurements, prior to and after
irradiation. We were thus able to quantify and to localize radiation
impacts onto the grafted polymers, revealing the production sites of
reactive species around AuNPs. Both external and near-surface scissions were observed. Interestingly, the ratio between these
two e
ff
ects was found to vary according to the nature of polymer ligands. Medium-range and long-distance dose enhancements
could not be identi
fi
ed from the calculated scission yields, but several mechanisms were considered to explain high yields found
for near-surface scissions. Then cytotoxicity was shown to be equivalent for both nonirradiated and irradiated polymer-grafted
NPs, which suggested that released polymer fragments were nontoxic. Finally, the potential to add bioactive molecules such as
anticancer drugs has been explored by grafting doxorubicin onto the polymer corona. This may lead to nano-objects combining
both radiosensitization and chemotherapy e
ff
ects. This work is the
fi
rst one to study in details the impact of radiation on
radiosensitizing nano-objects combining physical, chemical, and biological analyses.