Metal-Based Radiopharmaceuticals Take Centre Stage at ISABC 2023
The 16th International Symposium on Applied Bioinorganic Chemistry convenes in Ioannina in June 2023, drawing chemists, pharmacists, clinicians, and nuclear medicine specialists to discuss how coordination chemistry is reshaping imaging and therapy. A keynote on metal-based radiopharmaceuticals is among the highlights.
Bioinorganic chemistry supplies the ligands, oxidation states, and kinetic understanding that decide whether a radiolabelled agent reaches its target intact. The Ioannina programme, led by the University of Ioannina, spans radiochemistry, metallodrugs, and imaging agents.
Lake Pamvotis and the Zagori villages provide the backdrop, with Zita Congress & Event Management as the official secretariat. For Australian delegates weighing the long flight from Sydney or Melbourne, the venue may itself be a draw.
Down under, theranostics is no longer academic. Australian centres have been early adopters of gallium-68 and lutetium-177 workflows, and ANSTO's domestic isotope production keeps radiochemists and clinicians tightly coupled. The keynote therefore lands with practical resonance.
Theranostics and the Bioinorganic Imperative
A radiopharmaceutical that can be switched from diagnostic to therapeutic isotope is no longer hypothetical. Pairs such as gallium-68 and lutetium-177 already underpin approved regimens for metastatic prostate cancer and gastroenteropancreatic neuroendocrine tumours, and the underlying chemistry is squarely bioinorganic. Choosing the right chelator, oxidation state, and kinetic profile determines whether a single targeting vector can serve twice without image degradation or off-target dose.
The keynote frames these choices through applied bioinorganic chemistry, tracing the path from first principles to first-in-human studies. Small modifications to DOTA or sarcophagine scaffolds can shift biodistribution, alter bone marrow uptake, or improve tumour-to-kidney ratios.
In Australia, theranostic clinics in Melbourne, Brisbane, and Perth have built multi-disciplinary teams around these concepts. Nuclear medicine physicians, medical oncologists, radiopharmacists, and radiochemists consult side by side, with ANSTO handling upstream isotope logistics.
Imaging Nuclides and Their Coordination Chemistry
For diagnosis, the field relies on positron emitters such as copper-64, zirconium-89, scandium-44, and gallium-68, alongside single-photon emitters including technetium-99m and indium-111. Each carries a distinct half-life, emission energy, and coordination preference. Copper tolerates a wider chelator palette than gallium but needs tighter redox control, while zirconium-89 matches antibody pharmacokinetics but demands exceptionally inert oxo clusters.
These distinctions govern image quality, scan duration, and dose. Gallium-68 supports same-day PET, whereas zirconium-89 enables multi-day biodistribution studies that mirror intact antibody kinetics.
ANSTO's OPAL reactor and adjacent facilities supply much of Australia's molybdenum-99, decaying to technetium-99m for SPECT imaging in hospitals from Royal North Shore to the Royal Adelaide, giving Australian researchers a privileged vantage on chelator design.
Therapeutic Nuclides: Alpha, Beta, and Beyond
Therapeutic radiopharmaceuticals deliver cytotoxic radiation over short pathlengths. Lutetium-177 and yttrium-90 remain the beta-emitting workhorses, with iodine-131 still dominant in thyroid disease. Alpha emitters such as actinium-225, bismuth-213, lead-212, and terbium-149 are attracting intense interest for their high linear energy transfer and short range, with the potential to sterilise microscopic tumour deposits while sparing healthy tissue.
Producing and stably coordinating such exotic nuclides is fundamentally bioinorganic. Actinium-225 has no stable isotope, and its radioactive daughters can recoil out of conventional chelators if the parent complex is not robust. New ligands tailored for large, highly charged actinides are a frontier the Ioannina programme addresses directly.
Australia has entered cautiously but visibly, with early-phase trials of actinium-225-PSMA at the Peter MacCallum Cancer Centre and a small but growing trials network coordinated through the Australasian Radiopharmaceutical Trials Network.
Ligand Design and Bifunctional Chelators
The chelator sits at the heart of every metal-based radiopharmaceutical, and the keynote explores how its design must accommodate the radioisotope, the targeting biomolecule, and the biological milieu. Macrocyclic DOTA and NOTA derivatives dominate clinical use, but sarcophagines, pyridines, and constrained peptidic chelators are expanding the design space.
A bifunctional chelator carries both the metal-binding pocket and a reactive handle for attaching peptides, antibodies, or small molecules. Click chemistries, strain-promoted azide-alkyne cycloaddition, and maleimide-thiol coupling all feature, each with trade-offs in selectivity, kinetics, and shelf life.
Australian Research Hubs and Training Pipelines
Australian radiochemistry is anchored by ANSTO and the Australian Synchrotron in Melbourne, with strong university programmes at Melbourne, Monash, the Australian National University, the University of Sydney, and the University of Queensland. Each combines fundamental coordination chemistry with translational radiochemistry within shared facilities.
Small-animal PET and SPECT imaging at the Australian Synchrotron's beamlines bridge the gap between bench and bedside. The Australasian Association of Nuclear Medicine Specialists and the Australian and New Zealand Society of Nuclear Medicine set professional standards for clinicians delivering these treatments.
For early-career Australian researchers, this ecosystem offers a path from a chelator idea to a first-in-human study, supported by scholarships from the Australian Institute of Nuclear Science and Engineering and travel support from the Australian Academy of Science.
Clinical Translation in the Australian Setting
Translating a metal-based radiopharmaceutical into routine clinical service is regulatory as much as scientific. Sponsors navigate the Therapeutic Goods Administration and ARPANSA, with funding decisions passing through the Pharmaceutical Benefits Advisory Committee and the Medicare Benefits Schedule. Recent listings for PSMA PET imaging and lutetium-177 PSMA therapy have narrowed the gap between evidence and access for Australian patients.
Cooperative groups such as the Trans-Tasman Radiation Oncology Group and the Australian and New Zealand Urogenital and Prostate Cancer Trials Group routinely incorporate theranostic sub-studies. ISABC speakers will contextualise these realities against European Medicines Agency and United States Food and Drug Administration frameworks, making the Ioannina programme globally comparative.
Symposium Highlights, Networking, and Abstracts
The keynote anchors a programme including symposia on copper and actinide chemistry, metallodrugs, and imaging agents, plus an industrial exhibition. Plenary lectures are paired with contributed talks and posters, with prizes for outstanding student presentations. Travel awards and scholarships have been confirmed for young scientists, a useful entry point for early-career Australians.
Beyond the lecture theatres, collaboration is forged over coffee, dinner, and shared excursions. The conference dinner by Lake Pamvotis and guided tours of the old town and Zagori villages form part of the programme, and the official networking social events page sets out the schedule in full.
Contributors can prepare submissions through the official abstract submission portal before the published cutoff. The portal accepts oral and poster contributions across all bioinorganic themes.
Those ready to register can use the event platform partner supporting the secretariat, with full details handled by Zita Congress & Event Management. Mark June 2023 in your diary now, and plan to be in Ioannina, where the next generation of metal-based radiopharmaceuticals will be debated, refined, and set on their path to the clinic.