title: Synchrotron microbeam irradiation induces neutrophil infiltration, thrombocyte attachment and selective vascular damage in vivo.
abstract: Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25-100 μm wide) and minibeams (200-800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a(+) thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. We demonstrate that vascular damage, inflammatory processes and cellular toxicity depend on the beam width and the stage of tissue maturation. Minibeam irradiation did not differentiate between mature and immature tissue. In contrast, all irradiation-induced effects of the microbeams were restricted to the rapidly growing immature tissue, indicating that microbeam irradiation could be a promising tumor treatment tool.
authors.affiliation: Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Brönnimann
authors.affiliation: Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
authors.forename: Audrey
authors.initials: A
authors.lastname: Bouchet
authors.affiliation: Institute of Pharmacology, University of Bern, Inselspital INO-F, 3010 Bern, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schneider
authors.affiliation: Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
authors.forename: Marine
authors.initials: M
authors.lastname: Potez
authors.affiliation: Université Grenoble Alpes, EA-Rayonnement Synchrotron et Recherche Medicale, ESRF, ID17 F-38043 Grenoble, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Serduc
authors.affiliation: Biomedical Beamline, European Synchrotron Radiation Facility, BP220, F38043 Grenoble, France.
authors.forename: Elke
authors.initials: E
authors.lastname: Bräuer-Krisch
authors.affiliation: Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Graber
authors.affiliation: Institute of Pharmacology, University of Bern, Inselspital INO-F, 3010 Bern, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: von Gunten
authors.affiliation: Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
authors.forename: Jean Albert
authors.initials: JA
authors.lastname: Laissue
authors.affiliation: Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
authors.forename: Valentin
authors.initials: V
authors.lastname: Djonov
mesh_terms: D058500:Animal Fins / Q000098:blood supply / Q000528:radiation effects / Q000648:ultrastructure; D000818:Animals; D001792:Blood Platelets / Q000528:radiation effects*; D001808:Blood Vessels / Q000473:pathology*; D003238:Connective Tissue / Q000473:pathology; D006487:Hemostasis; D007249:Inflammation / Q000473:pathology; D020556:Neutrophil Infiltration / Q000528:radiation effects*; D010477:Perfusion; D010973:Platelet Adhesiveness / Q000528:radiation effects*; D017356:Synchrotrons; D015027:Zebrafish