{"entity": "publication", "iuid": "e0282ea73d7642409e609ba943c8fec6", "timestamp": "2026-09-01T08:31:30.404Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/e0282ea73d7642409e609ba943c8fec6.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/e0282ea73d7642409e609ba943c8fec6"}}, "title": "Preclinical evaluation of Affibody molecule for PET imaging of human pancreatic islets derived from stem cells.", "authors": [{"family": "Cheung", "given": "Pierre", "initials": "P"}, {"family": "Thorngren", "given": "Julia", "initials": "J"}, {"family": "Zhang", "given": "Bo", "initials": "B"}, {"family": "Vasylovska", "given": "Svitlana", "initials": "S"}, {"family": "Lechi", "given": "Francesco", "initials": "F"}, {"family": "Persson", "given": "Jonas", "initials": "J"}, {"family": "St\u00e5hl", "given": "Stefan", "initials": "S"}, {"family": "L\u00f6fblom", "given": "John", "initials": "J"}, {"family": "Korsgren", "given": "Olle", "initials": "O"}, {"family": "Eriksson", "given": "Jonas", "initials": "J"}, {"family": "Lau", "given": "Joey", "initials": "J"}, {"family": "Eriksson", "given": "Olof", "initials": "O"}], "type": "journal article", "published": "2023-12-15", "journal": {"title": "EJNMMI Res", "issn": "2191-219X", "volume": "13", "issue": "1", "pages": "107", "issn-l": "2191-219X"}, "abstract": "Beta-cell replacement methods such as transplantation of isolated donor islets have been proposed as a curative treatment of type 1 diabetes, but widespread application is challenging due to shortages of donor tissue and the need for continuous immunosuppressive treatments. Stem-cell-derived islets have been suggested as an alternative source of beta cells, but face transplantation protocols optimization difficulties, mainly due to a lack of available methods and markers to directly monitor grafts survival, as well as their localization and function. Molecular imaging techniques and particularly positron emission tomography has been suggested as a tool for monitoring the fate of islets after clinical transplantation. The integral membrane protein DGCR2 has been demonstrated to be a potential pancreatic islet biomarker, with specific expression on insulin-positive human embryonic stem-cell-derived pancreatic progenitor cells. The candidate Affibody molecule ZDGCR2:AM106 was radiolabeled with fluorine-18 using a novel click chemistry-based approach. The resulting positron emission tomography tracer [18F]ZDGCR2:AM106 was evaluated for binding to recombinant human DGCR2 and cryosections of stem-cell-derived islets, as well as in vivo using an immune-deficient mouse model transplanted with stem-cell-derived islets. Biodistribution of the [18F]ZDGCR2:AM106 was also assessed in healthy rats and pigs.\n\n[18F]ZDGCR2:AM106 was successfully synthesized with high radiochemical purity and yield via a pretargeting approach. [18F]ZDGCR2:AM106 retained binding to recombinant human DCGR2 as well as to cryosectioned stem-cell-derived islets, but in vivo binding to native pancreatic tissue in both rat and pig was low. However, in vivo uptake of [18F]ZDGCR2:AM106 in stem-cell-derived islets transplanted in the immunodeficient mice was observed, albeit only within the early imaging frames after injection of the radiotracer.\n\nTargeting of DGCR2 is a promising approach for in vivo detection of stem-cell-derived islets grafts by molecular imaging. The synthesis of [18F]ZDGCR2:AM106 was successfully performed via a pretargeting method to label a site-specific covalently bonded fluorine-18 to the Affibody molecule. However, the rapid washout of [18F]ZDGCR2:AM106 from the stem-cell-derived islets graft indicates that dissociation kinetics can be improved. Further studies using alternative binders of similar classes with improved binding potential are warranted.", "doi": "10.1186/s13550-023-01057-3", "pmid": "38100042", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC10724103"}, {"db": "pii", "key": "10.1186/s13550-023-01057-3"}], "notes": [], "created": "2026-08-20T12:36:49.257Z", "modified": "2026-08-20T12:36:49.305Z"}