S C

IE N

T IF

IC H

IG H

LI G

H T

S X

-R A

Y N

A N

O P

R O

B E

1 0 3 I H I G H L I G H T S 2 0 2 1

the Fe ions remain in the +3 oxidation state, the spectra obtained evolved to a ferrihydrite-like structure. The spectra could then be reproduced with a mixture of ferrihydrite and maghemite, demonstrating that 80% of the maghemite was transformed to ferrihydrite.

By contrast, XANES analysis at the Cu K-edge showed no change at all for the chemical phase and environment of Cu over maturation within the spheroids, despite their disassembling to smaller units. The XANES spectrum of the sample in solution displayed identical edge positions and spectral features to those obtained in cells with time. A fit of the XANES region of the samples using Cu-based reference compounds yielded a composition of mainly CuS

phase combined with other Cu-based compounds in lower proportion. This is in agreement with the preservation of the photothermal potential, and provides evidence of massive intracellular transformation of the nano-assemblies to CuS biologically bioprocessed materials with same structural chemistry and thus physical functional (photothermal) properties.

This demonstration of bio-stability of a therapeutic physical function upon biological bioprocessing bodes well for future theranostic applications of CuS-based nanomaterials and shows the superiority of CuS materials as a promising photothermal multifunctional theranostic platform over metal-based ones.

Fig. 84: XANES absorption spectra at the Fe K-edge (left) of iron oxide references (maghemite and ferrihydrite), Iron Oxide@CuS nano-assemblies incubated from day 1 to day 21 and also in solution. XANES absorption spectra at the Cu K-edge (right) of copper-based compounds (CuSO4·5H2O, CuO and CuS), Iron Oxide@CuS nano-assemblies incubated from day 1 to day 21 and in solution.

PRINCIPAL PUBLICATION AND AUTHORS

Massive Intracellular Remodeling of CuS Nanomaterials Produces Nontoxic Bioengineered Structures with Preserved Photothermal Potential, A. Curcio (a,b), A. Van de Walle (a,b), E. Benassai (b,c), A. Serrano (d,e), N. Luciani (a), N. Menguy (f), B.B. Manshian (g), A. Sargsian (g), S. Soenen (g), A. Espinosa (h), A. Abou-Hassan (c), C. Wilhelm (a,b), ACS Nano 15, 9782-9795 (2021); https:/ www.doi.org/10.1021/acsnano.1c00567 (a) Laboratoire Matière et Systèmes Complexes MSC, UMR 7057, CNRS & University of Paris, (France) (b) Laboratoire PhysicoChimie Curie, Institut Curie, PSL Research University - Sorbonne Université CNRS, Paris (France) (c) Sorbonne Université, CNRS UMR234, PHysico-chimie des Electrolytes et Nanosystèmes InterfaciauX, PHENIX, Paris (France) (d) ESRF (e) Departamento de Electrocerámica, Instituto de Cerámica y Vidrio, ICV-CSIC, Madrid (Spain) (f) Sorbonne Université, UMR CNRS 7590, MNHN, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris (France) (g) NanoHealth and Optical Imaging Group, KU Leuven, Department of Imaging and Pathology, Leuven (Belgium) (h) IMDEA Nanociencia & Nanobiotecnología, Unidad Asociada al Centro Nacional de Biotecnología (CSIC), Madrid (Spain)

REFERENCES

[1] A. Van de Walle et al., Acc. Chem. Res. 53, 2212- 2224 (2020). [2] A. Curcio et al., Theranostics 9, 1288 (2019).