ORCID Profile
0000-0002-9408-8108
Current Organisation
Institut des Sciences et Technologies Moléculaires d'Angers/CNRS
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Publisher: Oxford University Press (OUP)
Date: 16-05-2023
DOI: 10.1093/NAR/GKAD365
Abstract: Photodynamic therapy (PDT) ideally relies on the administration, selective accumulation and photoactivation of a photosensitizer (PS) into diseased tissues. In this context, we report a new heavy-atom-free fluorescent G-quadruplex (G4) DNA-binding PS, named DBI. We reveal by fluorescence microscopy that DBI preferentially localizes in intraluminal vesicles (ILVs), precursors of exosomes, which are key components of cancer cell proliferation. Moreover, purified exosomal DNA was recognized by a G4-specific antibody, thus highlighting the presence of such G4-forming sequences in the vesicles. Despite the absence of fluorescence signal from DBI in nuclei, light-irradiated DBI-treated cells generated reactive oxygen species (ROS), triggering a 3-fold increase of nuclear G4 foci, slowing fork progression and elevated levels of both DNA base damage, 8-oxoguanine, and double-stranded DNA breaks. Consequently, DBI was found to exert significant phototoxic effects (at nanomolar scale) toward cancer cell lines and tumor organoids. Furthermore, in vivo testing reveals that photoactivation of DBI induces not only G4 formation and DNA damage but also apoptosis in zebrafish, specifically in the area where DBI had accumulated. Collectively, this approach shows significant promise for image-guided PDT.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CP01072C
Abstract: Substituent induced distortion effects play a crucial role in enhancing the intersystem crossing kinetics in benzothioxanthene imide derivatives.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CC04556J
Abstract: The synthesis of benzothioxanthene imide based dimers and their first use in light emitting devices are reported herein.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2QM00299J
Abstract: Synthesis and use of the unprecedented thiochromenocarbazole imide (TCI) for the preparation of printed, large-area and flexible OLEDs.
Publisher: American Chemical Society (ACS)
Date: 04-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9NJ05804D
Abstract: The selective mono-nitration of benzothioxanthene ( BTXI ) is demonstrated here, opening doors to a wide range of structures and reactions. In addition, a new series of derivaties was characterized expanding the scope for electronic organic purposes.
Publisher: American Chemical Society (ACS)
Date: 22-07-2021
Abstract: Singlet-triplet interconversions (intersystem crossing, ISC) in organic molecules are at the basis of many important processes in cutting-edge photonic applications (organic light-emitting devices, photodynamic therapy, etc.). Selection rules for these transitions are mainly governed by the spin-orbit coupling (SOC) phenomenon. Although the SOC relies on complex relativistic phenomena, theoreticians have, with time, developed increasingly sophisticated and efficient approaches to gain access to a satisfactory evaluation of its magnitude. However, recent works have highlighted the remarkable and somehow unexpected efficiency of dimers of small conjugated molecules in terms of ISC quantum yields, whose origin has not been completely investigated. In this work, we bring a coupled experimental and theoretical analysis of the origin of the unusually large ISC efficiency on a series of such dimers that differ by their nature (covalent or supramolecular). We show that considering the dynamical nature of the SOC, and especially its dependence on angular orientations between the dimer subunits sometimes overlooked in the literature, it is necessary to rationalize some counterintuitive experimental observations. This combined experimental and theoretical work paves the way for new molecular engineering rules for SOC control.
Location: France
No related grants have been discovered for Philippe BLANCHARD.