Konstruktionswerkstoffe
Die Sicherheit kerntechnischer Anlagen wird maßgeblich durch das mechanische Werkstoffverhalten unter extremen Betriebsbedingungen (Neutronenbestrahlung, hohe Temperaturen) bestimmt. Im Rahmen des Programms NUSAFE (Nuclear Waste Management, Safety and Radiation Research) der Helmholtz-Gemeinschaft untersuchen wir skalenübergreifend das Schädigungs- und Bruchverhalten von bestrahlten Reaktorwerkstoffen. Im Fokus stehen die
- Untersuchung von Langzeitbestrahlungseffekten in Reaktordruckbehälterstähle laufender und neuer Reaktoren im Hinblick auf Laufzeitverlängerung
- Beurteilung der Bestrahlungstoleranz innovativer Werkstoffe für zukünftige Reaktorkonzepte einschließlich Kernfusion
(e.g. ferritisch/martensitische Chromstähle, oxiddisperionsverfestigte Stähle, neuartige Hochentropielegierungen)
Das methodische Spektrum erlaubt die Betrachtung der gesamten Wirkungskette von Bestrahlungseffekten auf der nm-Skala bis zum makroskopischen mechanischen Werkstoffverhalten. Ziel ist es, Bestrahlungseffekte zu erkennen, besser zu verstehen und zu mildern. Mit den heißen Zellen zur Untersuchung neutronenbestrahlter Materialien und dem Ionenstrahlzentrum für Ionenbestrahlungsexperimente verfügt das HZDR über eine einzigartige Infrastruktur.
Unsere Expertise:
- Bruchmechanische Prüfung bestrahlter Werkstoffe
- Nano-/Mikrostrukturcharakterisierung bestrahlter Stähle
- Ionenbestrahlung zur Emulation neutroneninduzierter Defekte
Laufende Projekte
- Innovative structural materials for fission and fusion
(INNUMAT, EU, HORIZON-EURATOM, 2022-2026) - European Database for Multiscale Modelling of Radiation Damage
(ENTENTE, EU-H2020-Euratom, 2020-2024) - Fracture mechanics testing of irradiated RPV steels by means of sub-sized specimens
(FRACTESUS, EU-H2020-Euratom, 2020-2024) - Structural Materials research for safe Long Term Operation of LWR NPPs
(STRUMAT-LTO, EU-H2020-Euratom, 2020-2024) - Untersuchungen zum Ausheilverhalten von Reaktordruckbehälterstählen bei niedrigen Temperaturen
(WetAnnealing, BMWI, 2020-2025) - Physical modelling and modelling-oriented experiments for structural materials 2
(IOANIS2, EERA-JPNM Pilotprojekt, 2023 - 2027, Koordinator HZDR) - In-situ experiments for nuclear applications
(INSITEX, EERA-JPNM Pilotprojekt, 2023 - 2027) - On the use of small punch as high-throughput screening technique to extract mechanical properties of ion irradiated materials
(SHERPA, EERA-JPNM Pilotprojekt, 2023 - 2027)
Neuste Publikation
Development of cathepsin B-activatable cell-penetrating peptides for tumor targeting
Kuhne, K.; Strohbach, L.; Neuber, C.; Wodtke, R.; Ruiz-Gomez, G.; Belter, B.; Brandt, F.; Gluhacevic von Krüchten, L.; Keller, M.; Pisabarro, M. T.; Kopka, K.; Pietzsch, J.; Löser, R.
Abstract
Extracellular cathepsin B is a driver of tumor progression and metastasis, and its potential as diagnostic and prognostic marker is increasingly recognized. To harness its activity for triggering the uptake of activatable cell-penetrating peptides (ACPP) in vivo, kinetically suitable and stable endopeptidase substrates for this cysteine protease, which mainly acts as carboxydipeptidase, are required. This challenge was tackled by C-terminal elongation of the previously identified GIVRAK sequence to octapeptides and systematic structural variation, which has revealed that endopeptidase activity of cathepsin B is associated with kinetic hysteresis and the P4’ residue plays a key role in this regard, as further investigated by enzyme-substrate docking in silico. By replacing the N-terminal motif with GFLG and focused N-methylation of the backbone, substrate serum half-life was extended from 3.7 min to 23.4 h. Integrating this sequence into the fluorophore-conjugated ACPP and fluorescence microscopy in U87MG cells confirmed cathepsin B-mediated uptake on the basis of selective inhibitors and control probes. PET imaging and biodistribution studies ex vivo with a NODAGA-conjugated ACPP analogue radiolabeled with copper-64 in a murine U87MG-derived xenograft model together with radiopharmacological investigations in normal Wistar rats demonstrated more favorable pharmacokinetics compared to the corresponding CPP. Although tumor-associated proteolytic activation in vivo is indicated, this does not contribute to tumor retention as judged from control experiments under pharmacological blockade of cathepsin B and with non-functional analogues. The obtained results are discussed in context of previous data for radiolabeled ACPPs and implications for the general use of ACPPs for radiotheranostic approaches are highlighted.
Keywords: Copper-64; Kinetic hysteresis; PET imaging; Pharmacokinetics; Protease substrates; Theranostics
Verknüpfte Publikationen
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Data publication: Development of cathepsin B-activatable cell-penetrating …
ROBIS: 42870 HZDR-primary research data are used by this (Id 42228) publication
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ACS Pharmacology & Translational Science 9(2026)4, 966-996
DOI: 10.1021/acsptsci.5c00746
Permalink: https://www.hzdr.de/publications/Publ-42228
Team
Leitung | |||||
| Name | Geb./Raum | +49 351 260 | |||
|---|---|---|---|---|---|
| Dr. Eberhard Altstadt | e.altstadt | ||||
| Dr. Cornelia Kaden | 801/P102 | 3431 | c.kaden@hzdr.de, c.heintze | ||
Mitarbeiter | |||||
| Name | Geb./Raum | +49 351 260 | |||
| Dr. Paul Chekhonin | 801/P146 | 2149 | p.chekhonin | ||
| Vanessa Dykas | 801/P148 | 3363 | v.dykas | ||
| Mario Houska | 801/P148 | 2242 | m.houska | ||
| Jens Pietzsch | 801/P032 | 2814 3550 | jens.pietzsch | ||
| Dr. Andreas Ulbricht | 801/P146 | 3155 | |||
| Wolfgang Webersinke | 801/P148 | 2766 2129 | w.webersinke | ||
| Tilo Welz | 801/P032 | 2814 | t.welz | ||

