C O M P L E X S Y S T E M S A N D B I O M E D I C A L S C I E N C E S

S C I E N T I F I C H I G H L I G H T S

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Fig. 53: Non-linear response of 9L tumours to an increased number of MRT ports regarding the median

survival time of tumour-bearing rats.

Synchrotron Microbeam Radiation Therapy increases the therapeutic ratio for brain tumour treatment

This work demonstrates the potential of an innovative irradiation technique that ablates brain cancer while sparing normal tissues. Compared with conventional irradiation, multiport Microbeam Radiation Therapy (MRT) resulted in unexpectedly high equivalent biological effects in a tumour model. These effects have not been achieved with any other radiotherapeutic method.

Glioblastoma (GBM) is the most common type of human primary brain malignancy (48.3% [1]) and has the poorest prognosis [2], with aggressive treatment strategies such as conventional radiotherapy also eliciting severe side effects on normal tissues. Since 1994, the biomedical beamline ID17 has worked on developing an irradiation technique called Microbeam Radiation Therapy (MRT), which spatially fractionates an incident beam into parallel microbeams, allowing the deposition of several hundred grays in the targeted microbeam paths, while the areas of tissue between the microbeams only receive 5% to 10%

of the peak dose. This ensures that cell loss is confined to microbeam paths without disruption of mature vasculature, maintaining the continuous perfusion of normal tissues. To date, all preclinical MRT experiments on tumour models have investigated the effects of one single or two crossing orthogonal beam trajectories (or irradiation ports) [3]. However, one critical parameter, namely the number of ports, has never been systematically investigated until now. This work highlights the benefits of delivering very high radiation doses (hundreds of grays) to a 9L glioblastoma rat model via multiple arrays of parallel synchrotron X-ray microbeams (50 µm width).

Compared with crossed homogeneous Broad Beam (BB) irradiation, this work demonstrates that multiport MRT (with two to five ports, i.e., MRT2 to MRT5) optimises damage

PRINCIPAL PUBLICATION AND AUTHORS

Real-time multiscale monitoring and tailoring of graphene growth on liquid copper, M. Jankowski (a,b), M. Saedi (c), F. La Porta (b), A.C. Manikas (d), C. Tsakonas (d), J.S. Cingolani (e), M. Andersen (e), M. de Voogd (f), G.J.C. van Baarle (f), K. Reuter (e), C. Galiotis (d), G. Renaud (a), O.V. Konovalov (b), I.M.N. Groot (c), ACS Nano 15(6), 9638-9648 (2021); https:/doi.org/10.1021/acsnano.0c10377 (a) Université Grenoble Alpes, CEA, IRIG/MEM/NRS, Grenoble (France) (b) ESRF (c) Leiden Institute of Chemistry, Leiden University (The Netherlands) (d) FORTH/ICE-HT and Department of Chemical Engineering, University of Patras (Greece) (e) Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München (Germany) (f) Leiden Probe Microscopy (LPM) (The Netherlands)

REFERENCES

[1] C. Mattevi et al., J. Mater. Chem. 21, 3324 (2011). [2] C. Tsakonas et al., Nanoscale 13, 3346 (2021). [3] M. Saedi et al., Rev. Sci. Instrum. 91, 013907 (2020). [4] M. Jankowski et al., ACS Nano 15, 9638 (2021). [5] J.S. Cingolani et al., J. Chem. Phys. 153, 074702 (2020). [6] For more information: www.lmcat.eu

With a growth speed of ~1 µm/s, a sheet resistance of 280 Ohms/sq, and superior crystalline quality, this process is practically viable and paves the way for single- crystal graphene production for electronic applications. The real-time monitoring/tailoring methodology can also be implemented for the scientific study or industrial

production of other nanomaterials, such as h-BN, GaN, or ultrathin oxide layers. Finally, 2DM growth on LMCats has the potential to open up a radically new 2DM production method: that of continuous production via direct separation of 2DMs from the liquid catalyst [6].