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Background: The beneficial role of glucose-dependent insulinotropic polypeptide receptor (GIPR) in weight control and maintaining glucose levels has led to the development of several multi-agonistic peptide drug candidates, targeting GIPR and glucagon like peptide 1 receptor (GLP1R) and/or the glucagon receptor (GCGR). The in vivo quantification of target occupancy by these drugs would accelerate the development of new drug candidates. The aim of this study was to evaluate a novel peptide (GIP1234), based on previously reported ligand DOTA-GIP-C803, modified with a fatty acid moiety to prolong its blood circulation. It would allow higher target tissue exposure and consequently improved peptide uptake as well as in vivo PET imaging and quantification of GIPR occupancy by novel drugs of interest. Method: A 40 amino acid residue peptide (GIP1234) was synthesized based on DOTA-GIP-C803, in turn based on the sequences of endogenous GIP and Exendin-4 with specific amino acid modifications to obtain GIPR selectivity. A palmitoyl fatty acid chain was furthermore added at Lys14 via a glutamic acid linker to prolong its blood circulation time by the interaction with albumin. GIP1234 was conjugated with a DOTA chelator at the C -terminal cysteine residue to achieve 68Ga radiolabeling. The resulting PET probe, [68Ga]Ga-DOTA-GIP1234 was evaluated for receptor binding specificity and selectivity using HEK293 cells transfected with human GIPR, GLP1R, or GCGR. Blocking experiments with tirzepatide (2 mu M) were conducted using huGIPR HEK293 cells to investigate binding specificity. Ex vivo and in vivo organ distribution of [68Ga]Ga-DOTA-GIP1234 was studied in rats and a pig in comparison to [68Ga]Ga-DOTA-C803-GIP. Binding of [68Ga]Ga-DOTA-GIP1234 to albumin was assessed in situ using polyacrylamide gel electrophoresis (PAGE). The stability was tested in formulation buffer and rat blood plasma. Results: [68Ga]Ga-DOTA-GIP1234 was synthesized with non-decay corrected radiochemical yie, The last two authors contributed equally

Background: The beneficial role of glucose-dependent insulinotropic polypeptide receptor (GIPR) in weight control and maintaining glucose levels has led to the development of several multi-agonistic peptide drug candidates, targeting GIPR and glucagon like peptide 1 receptor (GLP1R) and/or the glucagon receptor (GCGR). The in vivo quantification of target occupancy by these drugs would accelerate the development of new drug candidates. The aim of this study was to evaluate a novel peptide (GIP1234), based on previously reported ligand DOTA-GIP-C803, modified with a fatty acid moiety to prolong its blood circulation. It would allow higher target tissue exposure and consequently improved peptide uptake as well as in vivo PET imaging and quantification of GIPR occupancy by novel drugs of interest. Method: A 40 amino acid residue peptide (GIP1234) was synthesized based on DOTA-GIP-C803, in turn based on the sequences of endogenous GIP and Exendin-4 with specific amino acid modifications to obtain GIPR selectivity. A palmitoyl fatty acid chain was furthermore added at Lys14 via a glutamic acid linker to prolong its blood circulation time by the interaction with albumin. GIP1234 was conjugated with a DOTA chelator at the C -terminal cysteine residue to achieve 68Ga radiolabeling. The resulting PET probe, [68Ga]Ga-DOTA-GIP1234 was evaluated for receptor binding specificity and selectivity using HEK293 cells transfected with human GIPR, GLP1R, or GCGR. Blocking experiments with tirzepatide (2 mu M) were conducted using huGIPR HEK293 cells to investigate binding specificity. Ex vivo and in vivo organ distribution of [68Ga]Ga-DOTA-GIP1234 was studied in rats and a pig in comparison to [68Ga]Ga-DOTA-C803-GIP. Binding of [68Ga]Ga-DOTA-GIP1234 to albumin was assessed in situ using polyacrylamide gel electrophoresis (PAGE). The stability was tested in formulation buffer and rat blood plasma. Results: [68Ga]Ga-DOTA-GIP1234 was synthesized with non-decay corrected radiochemical yie, The last two authors contributed equally

Primary aldosteronism (PA) is the leading secondary cause of hypertension. Determining whether one (unilateral) or both (bilateral) adrenal glands are the source of PA in a patient remains challenging, and yet it is a critical step in the decision whether to recommend potentially curative surgery (adrenalectomy) or lifelong medical therapy (typically requiring multiple drugs). Recently, we have developed a fluorine-18 radiopharmaceutical [(18) F]CETO to permit greater access to PA molecular imaging. Herein, we report an automated synthesis of this radiotracer. To manufacture the radiopharmaceutical routinely for clinical PET studies, we implemented an automated radiosynthesis method on a Synthra RNplus (c) synthesiser for which Cl-tosyletomidate was used as the precursor for radiolabelling via nucleophilic [(18) F]fluorination. [(18) F]CETO was produced with 35 +/- 1% (n = 7), decay corrected and 25 +/- 4% (n = 7) non-decay corrected radiochemical yield with molar activities ranging from 150 to 400 GBq/mu mol. The GMP compliant manufacturing process produces a sterile formulated [(18) F]CETO injectable solution for human use as demonstrated by the results of quality control. Automation of the radiosynthesis of [(18) F]CETO should facilitate uptake by other adrenal centres and increase access to molecular imaging in PA.

Primary aldosteronism (PA) is the leading secondary cause of hypertension. Determining whether one (unilateral) or both (bilateral) adrenal glands are the source of PA in a patient remains challenging, and yet it is a critical step in the decision whether to recommend potentially curative surgery (adrenalectomy) or lifelong medical therapy (typically requiring multiple drugs). Recently, we have developed a fluorine-18 radiopharmaceutical [(18) F]CETO to permit greater access to PA molecular imaging. Herein, we report an automated synthesis of this radiotracer. To manufacture the radiopharmaceutical routinely for clinical PET studies, we implemented an automated radiosynthesis method on a Synthra RNplus (c) synthesiser for which Cl-tosyletomidate was used as the precursor for radiolabelling via nucleophilic [(18) F]fluorination. [(18) F]CETO was produced with 35 +/- 1% (n = 7), decay corrected and 25 +/- 4% (n = 7) non-decay corrected radiochemical yield with molar activities ranging from 150 to 400 GBq/mu mol. The GMP compliant manufacturing process produces a sterile formulated [(18) F]CETO injectable solution for human use as demonstrated by the results of quality control. Automation of the radiosynthesis of [(18) F]CETO should facilitate uptake by other adrenal centres and increase access to molecular imaging in PA.

Primary aldosteronism (PA) is the leading secondary cause of hypertension. Determining whether one (unilateral) or both (bilateral) adrenal glands are the source of PA in a patient remains challenging, and yet it is a critical step in the decision whether to recommend potentially curative surgery (adrenalectomy) or lifelong medical therapy (typically requiring multiple drugs). Recently, we have developed a fluorine-18 radiopharmaceutical [(18) F]CETO to permit greater access to PA molecular imaging. Herein, we report an automated synthesis of this radiotracer. To manufacture the radiopharmaceutical routinely for clinical PET studies, we implemented an automated radiosynthesis method on a Synthra RNplus (c) synthesiser for which Cl-tosyletomidate was used as the precursor for radiolabelling via nucleophilic [(18) F]fluorination. [(18) F]CETO was produced with 35 +/- 1% (n = 7), decay corrected and 25 +/- 4% (n = 7) non-decay corrected radiochemical yield with molar activities ranging from 150 to 400 GBq/mu mol. The GMP compliant manufacturing process produces a sterile formulated [(18) F]CETO injectable solution for human use as demonstrated by the results of quality control. Automation of the radiosynthesis of [(18) F]CETO should facilitate uptake by other adrenal centres and increase access to molecular imaging in PA.

Background: The beneficial role of glucose-dependent insulinotropic polypeptide receptor (GIPR) in weight control and maintaining glucose levels has led to the development of several multi-agonistic peptide drug candidates, targeting GIPR and glucagon like peptide 1 receptor (GLP1R) and/or the glucagon receptor (GCGR). The in vivo quantification of target occupancy by these drugs would accelerate the development of new drug candidates. The aim of this study was to evaluate a novel peptide (GIP1234), based on previously reported ligand DOTA-GIP-C803, modified with a fatty acid moiety to prolong its blood circulation. It would allow higher target tissue exposure and consequently improved peptide uptake as well as in vivo PET imaging and quantification of GIPR occupancy by novel drugs of interest. Method: A 40 amino acid residue peptide (GIP1234) was synthesized based on DOTA-GIP-C803, in turn based on the sequences of endogenous GIP and Exendin-4 with specific amino acid modifications to obtain GIPR selectivity. A palmitoyl fatty acid chain was furthermore added at Lys14 via a glutamic acid linker to prolong its blood circulation time by the interaction with albumin. GIP1234 was conjugated with a DOTA chelator at the C -terminal cysteine residue to achieve 68Ga radiolabeling. The resulting PET probe, [68Ga]Ga-DOTA-GIP1234 was evaluated for receptor binding specificity and selectivity using HEK293 cells transfected with human GIPR, GLP1R, or GCGR. Blocking experiments with tirzepatide (2 mu M) were conducted using huGIPR HEK293 cells to investigate binding specificity. Ex vivo and in vivo organ distribution of [68Ga]Ga-DOTA-GIP1234 was studied in rats and a pig in comparison to [68Ga]Ga-DOTA-C803-GIP. Binding of [68Ga]Ga-DOTA-GIP1234 to albumin was assessed in situ using polyacrylamide gel electrophoresis (PAGE). The stability was tested in formulation buffer and rat blood plasma. Results: [68Ga]Ga-DOTA-GIP1234 was synthesized with non-decay corrected radiochemical yie, The last two authors contributed equally

Primary aldosteronism (PA) is the leading secondary cause of hypertension. Determining whether one (unilateral) or both (bilateral) adrenal glands are the source of PA in a patient remains challenging, and yet it is a critical step in the decision whether to recommend potentially curative surgery (adrenalectomy) or lifelong medical therapy (typically requiring multiple drugs). Recently, we have developed a fluorine-18 radiopharmaceutical [(18) F]CETO to permit greater access to PA molecular imaging. Herein, we report an automated synthesis of this radiotracer. To manufacture the radiopharmaceutical routinely for clinical PET studies, we implemented an automated radiosynthesis method on a Synthra RNplus (c) synthesiser for which Cl-tosyletomidate was used as the precursor for radiolabelling via nucleophilic [(18) F]fluorination. [(18) F]CETO was produced with 35 +/- 1% (n = 7), decay corrected and 25 +/- 4% (n = 7) non-decay corrected radiochemical yield with molar activities ranging from 150 to 400 GBq/mu mol. The GMP compliant manufacturing process produces a sterile formulated [(18) F]CETO injectable solution for human use as demonstrated by the results of quality control. Automation of the radiosynthesis of [(18) F]CETO should facilitate uptake by other adrenal centres and increase access to molecular imaging in PA.

Background: The beneficial role of glucose-dependent insulinotropic polypeptide receptor (GIPR) in weight control and maintaining glucose levels has led to the development of several multi-agonistic peptide drug candidates, targeting GIPR and glucagon like peptide 1 receptor (GLP1R) and/or the glucagon receptor (GCGR). The in vivo quantification of target occupancy by these drugs would accelerate the development of new drug candidates. The aim of this study was to evaluate a novel peptide (GIP1234), based on previously reported ligand DOTA-GIP-C803, modified with a fatty acid moiety to prolong its blood circulation. It would allow higher target tissue exposure and consequently improved peptide uptake as well as in vivo PET imaging and quantification of GIPR occupancy by novel drugs of interest. Method: A 40 amino acid residue peptide (GIP1234) was synthesized based on DOTA-GIP-C803, in turn based on the sequences of endogenous GIP and Exendin-4 with specific amino acid modifications to obtain GIPR selectivity. A palmitoyl fatty acid chain was furthermore added at Lys14 via a glutamic acid linker to prolong its blood circulation time by the interaction with albumin. GIP1234 was conjugated with a DOTA chelator at the C -terminal cysteine residue to achieve 68Ga radiolabeling. The resulting PET probe, [68Ga]Ga-DOTA-GIP1234 was evaluated for receptor binding specificity and selectivity using HEK293 cells transfected with human GIPR, GLP1R, or GCGR. Blocking experiments with tirzepatide (2 mu M) were conducted using huGIPR HEK293 cells to investigate binding specificity. Ex vivo and in vivo organ distribution of [68Ga]Ga-DOTA-GIP1234 was studied in rats and a pig in comparison to [68Ga]Ga-DOTA-C803-GIP. Binding of [68Ga]Ga-DOTA-GIP1234 to albumin was assessed in situ using polyacrylamide gel electrophoresis (PAGE). The stability was tested in formulation buffer and rat blood plasma. Results: [68Ga]Ga-DOTA-GIP1234 was synthesized with non-decay corrected radiochemical yie, The last two authors contributed equally

L'immunogénicité des tumeurs est un indicateur important de la réponse au traitement, y compris la radiothérapie (RT) et l'immunothérapie (IT). Les essais cliniques de l’IT avec les inhibiteurs de point de contrôle n'ont jusqu'à présent donné qu'un taux de réponse de 15% chez les patients atteints de cancer épidermoïde de la tête et du cou non sélectionnés. L'imagerie du microenvironnement immunitaire de la tumeur pourrait aider à guider la sélection des patients pouvant bénéficier le plus de l'IT. De plus, l'identification des patients atteints de tumeurs faiblement immunogènes peut guider l'investigation de thérapies supplémentaires, y compris la RT qui peut augmenter l'immunogénicité de la tumeur et améliorer l'efficacité de l'IT. L’objectif général de ce mémoire est le développement d’une méthode d’immuno-imagerie via le développement et la validation d’un nouveau radiotraceur le 89Zr-4HMSA-anti-CD3 pour suivre les lymphocytes infiltrant la tumeur et ainsi évaluer le statut immunitaire et l’immunogénicité de la tumeur. Le développement du radiotraceur a montré que les étapes de synthèse ont été réalisées efficacement et que le produit est démontré stable >95% ex vivo et in vivo. Les essais cellulaires ont montré que le radiotraceur est bien capté par les cellules EL4 avec un pourcentage qui atteint 38,36 ± 3,1 %AI/106 cellules après 3 jours. De plus, le test de la compétition avec le CD3 non radioactif a confirmé la spécificité de la liaison du 89Zr-4HMSA-anti-CD3 au marqueur CD3 de lymphocyte T. Par ailleurs, les études in vivo réalisées sur des modèles de souris porteuses de cancer de tête et du cou ou du cancer du côlon, ont montré que le radiotraceur développé a permis de visualiser l’infiltration des lymphocytes T CD3+ dans la tumeur tel qu’observé sur les images TEP préliminaires. Ce résultat a été confirmé par les données de la biodistribution. De plus, nous avons noté que le traitement par RT était capable d’augmenter l’infiltration lymphocytaire surtout, Tumor immunogenicity is an important indicator of treatment response, including radiotherapy (RT) and immunotherapy (IT). Immune checkpoint inhibitors have so far yielded only a 15% response rate in unselected patients with squamous cell carcinoma of the head and neck. Imaging the immune microenvironment of the tumor could help guide the selection of patients who might benefit most from IT. Additionally, identifying patients with poorly immunogenic tumors can guide the investigation of additional therapies, including RT, which can increase tumor immunogenicity and improve IT efficacy. The overall objective of this thesis is to develop an immuno-imaging method through the development and validation of a new radiotracer, 89Zr-4HMSA-anti-CD3. The method will be used to track tumor-infiltrating lymphocytes and thus assess the immunogenicity of the tumor. Our data show that the synthesis steps were efficiently carried out and that the product demonstrated stability at >95% ex vivo and in vivo. Cell assays showed that the radiotracer is well absorbed by T cells, with a percentage reaching of 38.36 ± 3.1 %IA/106 cells after 3 days. Furthermore, the competition test with non-radioactive CD3 confirmed the specific binding of 89Zr4HMSA-anti-CD3 to the CD3 marker on T lymphocytes. Additionally, in vivo studies conducted on mouse models with head and neck cancer or colon cancer showed that the developed radiotracer enabled visualization of CD3+ T lymphocyte infiltration into the tumor as observed in preliminary PET images. This result was confirmed by biodistribution data. Moreover, we noted that RT treatment was able to increase lymphocyte infiltration, especially in head and neck cancer (6.08 ± 0.34 %IA/g in the irradiated group vs. 3.05 ± 0.450 %IA/g in the non-irradiated group). Similarly, the co-injection of non-radioactive antiCD3 with the radiotracer showed that, although there was no blocking effect on tumor uptake, a decrease in the uptake of 89Zr-4HMSA-anti

Primary aldosteronism (PA) is the leading secondary cause of hypertension. Determining whether one (unilateral) or both (bilateral) adrenal glands are the source of PA in a patient remains challenging, and yet it is a critical step in the decision whether to recommend potentially curative surgery (adrenalectomy) or lifelong medical therapy (typically requiring multiple drugs). Recently, we have developed a fluorine-18 radiopharmaceutical [(18) F]CETO to permit greater access to PA molecular imaging. Herein, we report an automated synthesis of this radiotracer. To manufacture the radiopharmaceutical routinely for clinical PET studies, we implemented an automated radiosynthesis method on a Synthra RNplus (c) synthesiser for which Cl-tosyletomidate was used as the precursor for radiolabelling via nucleophilic [(18) F]fluorination. [(18) F]CETO was produced with 35 +/- 1% (n = 7), decay corrected and 25 +/- 4% (n = 7) non-decay corrected radiochemical yield with molar activities ranging from 150 to 400 GBq/mu mol. The GMP compliant manufacturing process produces a sterile formulated [(18) F]CETO injectable solution for human use as demonstrated by the results of quality control. Automation of the radiosynthesis of [(18) F]CETO should facilitate uptake by other adrenal centres and increase access to molecular imaging in PA.

Dementia with Lewy bodies is characterized by a high burden of autonomic dysfunction and Lewy pathology in peripheral organs and components of the sympathetic and parasympathetic nervous system. Parasympathetic terminals may be quantified with 18F-fluoroetoxybenzovesamicol, a PET tracer that binds to the vesicular acetylcholine transporter in cholinergic presynaptic terminals. Parasympathetic imaging may be useful for diagnostics, improving our understanding of autonomic dysfunction and for clarifying the spatiotemporal relationship of neuronal degeneration in prodromal disease. Therefore, we aimed to investigate the cholinergic parasympathetic integrity in peripheral organs and central autonomic regions of subjects with dementia with Lewy bodies and its association with subjective and objective measures of autonomic dysfunction. We hypothesized that organs with known parasympathetic innervation, especially the pancreas and colon, would have impaired cholinergic integrity. To achieve these aims, we conducted a cross-sectional comparison study including 23 newly diagnosed non-diabetic subjects with dementia with Lewy bodies (74 ± 6 years, 83% male) and 21 elderly control subjects (74 ± 6 years, 67% male). We obtained whole-body images to quantify PET uptake in peripheral organs and brain images to quantify PET uptake in regions of the brainstem and hypothalamus. Autonomic dysfunction was assessed with questionnaires and measurements of orthostatic blood pressure. Subjects with dementia with Lewy bodies displayed reduced cholinergic tracer uptake in the pancreas (32% reduction, P = 0.0003) and colon (19% reduction, P = 0.0048), but not in organs with little or no parasympathetic innervation. Tracer uptake in a region of the medulla oblongata overlapping the dorsal motor nucleus of the vagus correlated with autonomic symptoms (rs = −0.54, P = 0.0077) and changes in orthostatic blood pressure (rs = 0.76, P < 0.0001). Tracer uptake in the pedunculopontine region correlat

Background: The beneficial role of glucose-dependent insulinotropic polypeptide receptor (GIPR) in weight control and maintaining glucose levels has led to the development of several multi-agonistic peptide drug candidates, targeting GIPR and glucagon like peptide 1 receptor (GLP1R) and/or the glucagon receptor (GCGR). The in vivo quantification of target occupancy by these drugs would accelerate the development of new drug candidates. The aim of this study was to evaluate a novel peptide (GIP1234), based on previously reported ligand DOTA-GIP-C803, modified with a fatty acid moiety to prolong its blood circulation. It would allow higher target tissue exposure and consequently improved peptide uptake as well as in vivo PET imaging and quantification of GIPR occupancy by novel drugs of interest. Method: A 40 amino acid residue peptide (GIP1234) was synthesized based on DOTA-GIP-C803, in turn based on the sequences of endogenous GIP and Exendin-4 with specific amino acid modifications to obtain GIPR selectivity. A palmitoyl fatty acid chain was furthermore added at Lys14 via a glutamic acid linker to prolong its blood circulation time by the interaction with albumin. GIP1234 was conjugated with a DOTA chelator at the C -terminal cysteine residue to achieve 68Ga radiolabeling. The resulting PET probe, [68Ga]Ga-DOTA-GIP1234 was evaluated for receptor binding specificity and selectivity using HEK293 cells transfected with human GIPR, GLP1R, or GCGR. Blocking experiments with tirzepatide (2 mu M) were conducted using huGIPR HEK293 cells to investigate binding specificity. Ex vivo and in vivo organ distribution of [68Ga]Ga-DOTA-GIP1234 was studied in rats and a pig in comparison to [68Ga]Ga-DOTA-C803-GIP. Binding of [68Ga]Ga-DOTA-GIP1234 to albumin was assessed in situ using polyacrylamide gel electrophoresis (PAGE). The stability was tested in formulation buffer and rat blood plasma. Results: [68Ga]Ga-DOTA-GIP1234 was synthesized with non-decay corrected radiochemical yie, The last two authors contributed equally

Micro/nanomotors are useful tools for several biomedical applications, including targeted drug delivery and minimally invasive microsurgeries. However, major challenges such as in vivo imaging need to be addressed before they can be safely applied on a living body. Here, we show that positron emission tomography (PET), a molecular imaging technique widely used in medical imaging, can also be used to track a large population of tubular Au/PEDOT/Pt micromotors. Chemisorption of an iodine isotope onto the micromotor’s Au surface rendered them detectable by PET, and we could track their movements in a tubular phantom over time frames of up to 15 min. In a second set of experiments, micromotors and the bubbles released during self-propulsion were optically tracked by video imaging and bright-field microscopy. The results from direct optical tracking agreed with those from PET tracking, demonstrating that PET is a suitable technique for the imaging of large populations of active micromotors in opaque environments, thus opening opportunities for the use of this mature imaging technology for the in vivo localization of artificial swimmers., European Research Council (ERC), Ministerio de Economía y Competitividad, Alexander von Humboldt Foundation, Basque Regional Government, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

Discussed are two picolinate appended bispidine ligands (3,7-diazabicyclo[3.3.1]nonane derivatives) in comparison with an earlier described bis-pyridine derivative, which are all known to strongly bind CuII. The radiopharmacological characterization of the two isomeric bispidine complexes includes quantitative labeling with 64CuII at ambient conditions with high radiochemical purities and yields (molar activities > 200 MBq/nmol). Challenge experiments in presence of EDTA, cyclam, human serum and SOD demonstrate high stability and inertness of the 64Cu-bispidine complexes. Biodistribution studies performed in Wistar rats indicate a rapid renal elimination for both 64Cu-labeled chelates. The bispidine ligand with the picolinate group in N7 position was selected for further biological experiments, and its backbone was therefore substituted with a benzyl-NCS group at C9. Two tumor target modules (TMs), targeting prostate stem cell antigen (PSCA), overexpressed in prostate cancer, and the fibroblast activation protein (FAP) in fibrosarcoma, were selected for thiourea coupling with the NCS-functionalized ligand and lysine residues of TMs. Small animal PET experiments on tumor-bearing mice showed very good and specific accumulation of the 64Cu-labeled TMs in tumors.

Inflammation is our body’s sophisticated defense mechanism against invading pathogens, traumas, and tumors. Repeatable and non-invasive monitoring of inflammation process would open opportunities to improve our knowledge of several diseases and enable assessment of personalized treatments. Positron emission tomography (PET) combined with computed tomography (CT) has sufficient sensitivity to visualize the location of inflamed tissue in minimally invasive way. Paper I focused utilizing an already clinically available radiotracer [68Ga]Ga-DOTA-TATE as a macrophage marker for PET imaging in porcine and rodent models of pulmonary inflammation. In Paper II novel radiotracer [11C]GW457427 was evaluated as marker for neutrophil elastase expression in a large animal model of acute respiratory distress syndrome. In Paper III the most favorable Affibody molecule conjugate for SPECT and PET imaging of CD69 expression of activated immune cells was selected. Paper IV followed the results from Paper III and compared the uptake of [68Ga]Ga-DOTA-ZCAM241with a negative control Affibody molecule conjugate [68Ga]Ga-DOTA-ZAM106 in rheumatoid arthritis mouse model. [68Ga]Ga-DOTA-TATE had increased SUV uptake in the most damaged parts of the lungs in porcine lavage model, that corresponded with the results from CT images and quantification, histology staining and [18F]FDG uptake in Paper I . On the rat lung inflammation model the [68Ga]Ga-DOTA-TATE uptake was significantly increased in the damaged lungs compared with healthy control group. The uptake could also be blocked in vivo. Paper II demonstrated that the binding of the neutrophil elastase radiotracer [11C]GW457427 was specific and selective in vivo. SUV were especially elevated in damaged lung regions and neutrophil rich tissues bone marrow and spleen. Paper III indicated that the Affibody molecule variant ZCAM241 had the highest affinity for human and murine CD69 as well as the lowest background binding in SPECT images and was c

A hallmark of diabetes is the progressive loss of the beta-cell mass (BCM) and function. Most of the diagnostic methods for diabetes are mostly reflective of the beta-cell function, whereas current methodologies for studying the beta-cell mass are limited to post-mortem biopsies or highly invasive methods. Positron-emission tomography (PET) is a highly sensitive and quantitative medical imaging technique that was suggested as a tool for non-invasive imaging of the pancreas and quantification of the BCM. GPR44 is a membrane protein recently identified as a promising beta-cell biomarker highly expressed in beta cells, but not in other exocrine or endocrine tissues within the pancreas. Paper I describes the preclinical evaluation of the carbon-11 labeled GPR44 antagonist [11C]MK-7246 using cell lines and pigs. We have demonstrated strong binding of [11C]MK-7246 to the GPR44 receptor as well as its specificity to the pig pancreas. Based on the success of this study, we have initiated the clinical translation of [11C]MK-7246 to first-in-man BCM imaging studies in diabetic patients. As a direct continuation to paper I, paper II focused on the preclinical evaluation of MK-7246 labeled with a different isotope, namely fluorine-18. Additional characterizations were obtained such as the binding affinity and specificity to endocrine pancreatic fractions. Proof of concept in vivo GPR44 directed imaging has been demonstrated as well using an immunodeficient mouse model grafted with GPR44 expressing cells. Paper III is focused on the development and screening of first-in-class affibody molecules targeting DGCR2, another biomarker specific to beta cells. After binding and biodistribution assessments, the affibody molecule ZDGCR2:AM106 has been retained as the lead candidate for DGCR2 targeted imaging. In Paper IV, we have labeled the affibody molecule ZDGCR2:AM106 screened from paper III using fluorine-18, and the resulting [18F]ZDGCR2:AM106 has been assessed for in vivo PET ima

Simple Summary Prostate cancer continues to be the most frequently diagnosed form of cancer and the leading cause of cancer-related deaths among men. For a successful treatment plan and outcome, an early diagnosis, correct staging, and monitoring of treatment response are crucial. To improve this, a radiotracer could be used to target the two most abundant proteins overexpressed in prostate cancer: prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR). To date, no such heterodimeric radiotracer is used in the clinic. In this study, we have preclinically characterized and evaluated a galium-68 labelled PSMA/GRPR-targeting radiotracer for PET imaging of prostate cancer. We hope that the findings from this study will be able to contribute to designing better heterodimeric ligands, promote clinical translation of a heterodimer, and serve as a step towards a first-in-human study. The development of radioligands targeting prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR) has shown promising results for the imaging and therapy of prostate cancer. However, studies have shown that tumors and metastases can express such targets heterogeneously. To overcome this issue and to improve protein binding, radioligands with the ability to bind both PSMA and GRPR have been developed. Herein, we present the preclinical characterization of [Ga-68]Ga-BQ7812; a PSMA/GRPR-targeting radioligand for the diagnostic PET imaging of prostate cancer. This study aimed to evaluate [Ga-68]Ga-BQ7812 to promote the translation of such imaging probes into the clinic. [Ga-68]Ga-BQ7812 demonstrated rapid and specific binding to both targets in a PSMA/GRPR-expressing PC3-pip cell line. Results from the biodistribution study in PC3-pip xenografted mice showed specific binding to both targets, with the highest activity uptake at 1 h pi in tumor (PSMA+/GRPR+, 10.4 +/- 1.0% IA/g), kidneys (PSMA+, 45 +/- 16% IA/g), and pancreas (GRPR+, 5.6, De två första författarna delar förstaförfattarskapet.

Inflammation is our body’s sophisticated defense mechanism against invading pathogens, traumas, and tumors. Repeatable and non-invasive monitoring of inflammation process would open opportunities to improve our knowledge of several diseases and enable assessment of personalized treatments. Positron emission tomography (PET) combined with computed tomography (CT) has sufficient sensitivity to visualize the location of inflamed tissue in minimally invasive way. Paper I focused utilizing an already clinically available radiotracer [68Ga]Ga-DOTA-TATE as a macrophage marker for PET imaging in porcine and rodent models of pulmonary inflammation. In Paper II novel radiotracer [11C]GW457427 was evaluated as marker for neutrophil elastase expression in a large animal model of acute respiratory distress syndrome. In Paper III the most favorable Affibody molecule conjugate for SPECT and PET imaging of CD69 expression of activated immune cells was selected. Paper IV followed the results from Paper III and compared the uptake of [68Ga]Ga-DOTA-ZCAM241with a negative control Affibody molecule conjugate [68Ga]Ga-DOTA-ZAM106 in rheumatoid arthritis mouse model. [68Ga]Ga-DOTA-TATE had increased SUV uptake in the most damaged parts of the lungs in porcine lavage model, that corresponded with the results from CT images and quantification, histology staining and [18F]FDG uptake in Paper I . On the rat lung inflammation model the [68Ga]Ga-DOTA-TATE uptake was significantly increased in the damaged lungs compared with healthy control group. The uptake could also be blocked in vivo. Paper II demonstrated that the binding of the neutrophil elastase radiotracer [11C]GW457427 was specific and selective in vivo. SUV were especially elevated in damaged lung regions and neutrophil rich tissues bone marrow and spleen. Paper III indicated that the Affibody molecule variant ZCAM241 had the highest affinity for human and murine CD69 as well as the lowest background binding in SPECT images and was c

Simple Summary Prostate cancer continues to be the most frequently diagnosed form of cancer and the leading cause of cancer-related deaths among men. For a successful treatment plan and outcome, an early diagnosis, correct staging, and monitoring of treatment response are crucial. To improve this, a radiotracer could be used to target the two most abundant proteins overexpressed in prostate cancer: prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR). To date, no such heterodimeric radiotracer is used in the clinic. In this study, we have preclinically characterized and evaluated a galium-68 labelled PSMA/GRPR-targeting radiotracer for PET imaging of prostate cancer. We hope that the findings from this study will be able to contribute to designing better heterodimeric ligands, promote clinical translation of a heterodimer, and serve as a step towards a first-in-human study. The development of radioligands targeting prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR) has shown promising results for the imaging and therapy of prostate cancer. However, studies have shown that tumors and metastases can express such targets heterogeneously. To overcome this issue and to improve protein binding, radioligands with the ability to bind both PSMA and GRPR have been developed. Herein, we present the preclinical characterization of [Ga-68]Ga-BQ7812; a PSMA/GRPR-targeting radioligand for the diagnostic PET imaging of prostate cancer. This study aimed to evaluate [Ga-68]Ga-BQ7812 to promote the translation of such imaging probes into the clinic. [Ga-68]Ga-BQ7812 demonstrated rapid and specific binding to both targets in a PSMA/GRPR-expressing PC3-pip cell line. Results from the biodistribution study in PC3-pip xenografted mice showed specific binding to both targets, with the highest activity uptake at 1 h pi in tumor (PSMA+/GRPR+, 10.4 +/- 1.0% IA/g), kidneys (PSMA+, 45 +/- 16% IA/g), and pancreas (GRPR+, 5.6, De två första författarna delar förstaförfattarskapet.

Inflammation is our body’s sophisticated defense mechanism against invading pathogens, traumas, and tumors. Repeatable and non-invasive monitoring of inflammation process would open opportunities to improve our knowledge of several diseases and enable assessment of personalized treatments. Positron emission tomography (PET) combined with computed tomography (CT) has sufficient sensitivity to visualize the location of inflamed tissue in minimally invasive way. Paper I focused utilizing an already clinically available radiotracer [68Ga]Ga-DOTA-TATE as a macrophage marker for PET imaging in porcine and rodent models of pulmonary inflammation. In Paper II novel radiotracer [11C]GW457427 was evaluated as marker for neutrophil elastase expression in a large animal model of acute respiratory distress syndrome. In Paper III the most favorable Affibody molecule conjugate for SPECT and PET imaging of CD69 expression of activated immune cells was selected. Paper IV followed the results from Paper III and compared the uptake of [68Ga]Ga-DOTA-ZCAM241with a negative control Affibody molecule conjugate [68Ga]Ga-DOTA-ZAM106 in rheumatoid arthritis mouse model. [68Ga]Ga-DOTA-TATE had increased SUV uptake in the most damaged parts of the lungs in porcine lavage model, that corresponded with the results from CT images and quantification, histology staining and [18F]FDG uptake in Paper I . On the rat lung inflammation model the [68Ga]Ga-DOTA-TATE uptake was significantly increased in the damaged lungs compared with healthy control group. The uptake could also be blocked in vivo. Paper II demonstrated that the binding of the neutrophil elastase radiotracer [11C]GW457427 was specific and selective in vivo. SUV were especially elevated in damaged lung regions and neutrophil rich tissues bone marrow and spleen. Paper III indicated that the Affibody molecule variant ZCAM241 had the highest affinity for human and murine CD69 as well as the lowest background binding in SPECT images and was c

Simple Summary Prostate cancer continues to be the most frequently diagnosed form of cancer and the leading cause of cancer-related deaths among men. For a successful treatment plan and outcome, an early diagnosis, correct staging, and monitoring of treatment response are crucial. To improve this, a radiotracer could be used to target the two most abundant proteins overexpressed in prostate cancer: prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR). To date, no such heterodimeric radiotracer is used in the clinic. In this study, we have preclinically characterized and evaluated a galium-68 labelled PSMA/GRPR-targeting radiotracer for PET imaging of prostate cancer. We hope that the findings from this study will be able to contribute to designing better heterodimeric ligands, promote clinical translation of a heterodimer, and serve as a step towards a first-in-human study. The development of radioligands targeting prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR) has shown promising results for the imaging and therapy of prostate cancer. However, studies have shown that tumors and metastases can express such targets heterogeneously. To overcome this issue and to improve protein binding, radioligands with the ability to bind both PSMA and GRPR have been developed. Herein, we present the preclinical characterization of [Ga-68]Ga-BQ7812; a PSMA/GRPR-targeting radioligand for the diagnostic PET imaging of prostate cancer. This study aimed to evaluate [Ga-68]Ga-BQ7812 to promote the translation of such imaging probes into the clinic. [Ga-68]Ga-BQ7812 demonstrated rapid and specific binding to both targets in a PSMA/GRPR-expressing PC3-pip cell line. Results from the biodistribution study in PC3-pip xenografted mice showed specific binding to both targets, with the highest activity uptake at 1 h pi in tumor (PSMA+/GRPR+, 10.4 +/- 1.0% IA/g), kidneys (PSMA+, 45 +/- 16% IA/g), and pancreas (GRPR+, 5.6, De två första författarna delar förstaförfattarskapet.

Simple Summary Prostate cancer continues to be the most frequently diagnosed form of cancer and the leading cause of cancer-related deaths among men. For a successful treatment plan and outcome, an early diagnosis, correct staging, and monitoring of treatment response are crucial. To improve this, a radiotracer could be used to target the two most abundant proteins overexpressed in prostate cancer: prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR). To date, no such heterodimeric radiotracer is used in the clinic. In this study, we have preclinically characterized and evaluated a galium-68 labelled PSMA/GRPR-targeting radiotracer for PET imaging of prostate cancer. We hope that the findings from this study will be able to contribute to designing better heterodimeric ligands, promote clinical translation of a heterodimer, and serve as a step towards a first-in-human study. The development of radioligands targeting prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR) has shown promising results for the imaging and therapy of prostate cancer. However, studies have shown that tumors and metastases can express such targets heterogeneously. To overcome this issue and to improve protein binding, radioligands with the ability to bind both PSMA and GRPR have been developed. Herein, we present the preclinical characterization of [Ga-68]Ga-BQ7812; a PSMA/GRPR-targeting radioligand for the diagnostic PET imaging of prostate cancer. This study aimed to evaluate [Ga-68]Ga-BQ7812 to promote the translation of such imaging probes into the clinic. [Ga-68]Ga-BQ7812 demonstrated rapid and specific binding to both targets in a PSMA/GRPR-expressing PC3-pip cell line. Results from the biodistribution study in PC3-pip xenografted mice showed specific binding to both targets, with the highest activity uptake at 1 h pi in tumor (PSMA+/GRPR+, 10.4 +/- 1.0% IA/g), kidneys (PSMA+, 45 +/- 16% IA/g), and pancreas (GRPR+, 5.6, De två första författarna delar förstaförfattarskapet.

A hallmark of diabetes is the progressive loss of the beta-cell mass (BCM) and function. Most of the diagnostic methods for diabetes are mostly reflective of the beta-cell function, whereas current methodologies for studying the beta-cell mass are limited to post-mortem biopsies or highly invasive methods. Positron-emission tomography (PET) is a highly sensitive and quantitative medical imaging technique that was suggested as a tool for non-invasive imaging of the pancreas and quantification of the BCM. GPR44 is a membrane protein recently identified as a promising beta-cell biomarker highly expressed in beta cells, but not in other exocrine or endocrine tissues within the pancreas. Paper I describes the preclinical evaluation of the carbon-11 labeled GPR44 antagonist [11C]MK-7246 using cell lines and pigs. We have demonstrated strong binding of [11C]MK-7246 to the GPR44 receptor as well as its specificity to the pig pancreas. Based on the success of this study, we have initiated the clinical translation of [11C]MK-7246 to first-in-man BCM imaging studies in diabetic patients. As a direct continuation to paper I, paper II focused on the preclinical evaluation of MK-7246 labeled with a different isotope, namely fluorine-18. Additional characterizations were obtained such as the binding affinity and specificity to endocrine pancreatic fractions. Proof of concept in vivo GPR44 directed imaging has been demonstrated as well using an immunodeficient mouse model grafted with GPR44 expressing cells. Paper III is focused on the development and screening of first-in-class affibody molecules targeting DGCR2, another biomarker specific to beta cells. After binding and biodistribution assessments, the affibody molecule ZDGCR2:AM106 has been retained as the lead candidate for DGCR2 targeted imaging. In Paper IV, we have labeled the affibody molecule ZDGCR2:AM106 screened from paper III using fluorine-18, and the resulting [18F]ZDGCR2:AM106 has been assessed for in vivo PET ima

In rodents and nonhuman primates, sex hormones are powerful modulators of dopamine (DA) neurotransmission. Yet less is known about hormonal regulation of the DA system in the human brain. Using positron emission tomography (PET), we address this gap by comparing hormonal contraceptive users and nonusers across multiple aspects of DA function: DA synthesis capacity via the PET radioligand 6-[18F]fluoro-m-tyrosine ([18F]FMT), baseline D2/3 receptor binding potential using [11C]raclopride, and DA release using methylphenidate-paired [11C]raclopride. Participants consisted of 36 healthy women (n = 15 hormonal contraceptive users; n = 21 naturally cycling/non users of hormonal contraception), and men (n = 20) as a comparison group. A behavioral index of cognitive flexibility was assessed prior to PET imaging. Hormonal contraceptive users exhibited greater DA synthesis capacity than NC participants, particularly in dorsal caudate, and greater cognitive flexibility. Furthermore, across individuals, the magnitude of striatal DA synthesis capacity was associated with cognitive flexibility. No group differences were observed in D2/3 receptor binding or DA release. Analyses by sex alone may obscure underlying differences in DA synthesis tied to women's hormone status. Hormonal contraception (in the form of pill, shot, implant, ring, or intrauterine device) is used by ~400 million women worldwide, yet few studies have examined whether chronic hormonal manipulations impact basic properties of the DA system. Findings from this study begin to address this critical gap in women's health.

Introduction: Glioma are clinically challenging tumors due to their location and invasiveness, limiting their complete surgical resection. Mutated isocitrate dehydrogenase enzymes (IDH) are frequent alterations - the most common being the IDH1R132H - expressed only in glioma but not in healthy brain, correlating with prognosis. Hence, the evaluation of the IDH mutation status has become essential in clinical patient stratification. Currently, the IDH mutations are determined either directly by invasive biopsies or indirectly by magnetic resonance spectroscopy. Here, we propose a transdisciplinary approach to develop an 18F-labeled ligand to detect the IDH1R132H protein directly and non-invasively by positron emission tomography (PET) imaging. Such an imaging tool could improve the selection of cancer patients who are most likely to benefit from precision medicine. In the present study, we performed the radiofluorination of AG-120 (Ivosidenib), an FDA-approved small molecule inhibitor of mutant-IDH. Methods: The stannyl precursor (HL174) was synthetized according to the published synthesis of AG-120 [1] with minor modifications. The radiosynthesis was performed by copper-mediated radiofluorination of HL174 (Fig. 1) using a TRACERlab FX2 N synthesis module. The inhibitory potency of AG-120 was measured with a diaphorase/resazurin coupled assay using recombinant IDH1R132H or IDH1 (n=2). Internalization of [18F]AG-120 were determined in vitro using U251 human glioblastoma cells stably transfected with IDH1 or IDH1R132H [2]. In vivo metabolism was investigated in healthy CD-1 mice (n=3) by radio-chromatographic analyses of plasma and brain tissue. Dynamic PET (Mediso, nanoScan® PET/CT) imaging studies were performed in nude rats bearing U251-IDH1 (n=2) or U251-IDH1R132H (n=2) glioblastoma. Results: For the first time, diastereomerically pure [18F]AG-120 was prepared by an automated copper-mediated radiolabelling approach without azeotropic drying starting from the stanny

Background: Implant infections caused by biofilm forming bacteria are a major threat in orthopedic surgery. Delivering antibiotics directly to an implant affected by a bacterial biofilm via superparamagnetic nanoporous silica nanoparticles could present a promising approach. Nevertheless, short blood circulation half-life because of rapid interactions of nanoparticles with the host’s immune system hinder them from being clinically used. The aim of this study was to determine the temporal in vivo resolution of magnetic nanoporous silica nanoparticle (MNPSNP) distribution and the effect of PEGylation and clodronate application using PET/CT imaging and gamma counting in an implant mouse model. Methods: PEGylated and non-PEGylated MNPSNPs were radiolabeled with gallium-68 (68Ga), implementing the chelator tris(hydroxypyridinone). 36 mice were included in the study, 24 mice received a magnetic implant subcutaneously on the left and a titanium implant on the right hind leg. MNPSNP pharmacokinetics and implant accumulation was analyzed in dependence on PEGylation and additional clodronate application. Subsequently gamma counting was performed for further final analysis. Results: The pharmacokinetics and biodistribution of all radiolabeled nanoparticles could clearly be visualized and followed by dynamic PET/CT imaging. Both variants of 68Ga-labeled MNPSNP accumulated mainly in liver and spleen. PEGylation of the nanoparticles already resulted in lower liver uptakes. Combination with macrophage depletion led to a highly significant effect whereas macrophage depletion alone could not reveal significant differences. Although MNPSNP accumulation around implants was low in comparison to the inner organs in PET/CT imaging, gamma counting displayed a significantly higher %I.D./g for the tissue surrounding the magnetic implants compared to the titanium control. Additional PEGylation and/or macrophage depletion revealed no significant differences regarding nanoparticle accumulation

Introduction: Glioma are clinically challenging tumors due to their location and invasiveness, limiting their complete surgical resection. Mutated isocitrate dehydrogenase enzymes (IDH) are frequent alterations - the most common being the IDH1R132H - expressed only in glioma but not in healthy brain, correlating with prognosis. Hence, the evaluation of the IDH mutation status has become essential in clinical patient stratification. Currently, the IDH mutations are determined either directly by invasive biopsies or indirectly by magnetic resonance spectroscopy. Here, we propose a transdisciplinary approach to develop an 18F-labeled ligand to detect the IDH1R132H protein directly and non-invasively by positron emission tomography (PET) imaging. Such an imaging tool could improve the selection of cancer patients who are most likely to benefit from precision medicine. In the present study, we performed the radiofluorination of AG-120 (Ivosidenib), an FDA-approved small molecule inhibitor of mutant-IDH. Methods: The stannyl precursor (HL174) was synthetized according to the published synthesis of AG-120 [1] with minor modifications. The radiosynthesis was performed by copper-mediated radiofluorination of HL174 (Fig. 1) using a TRACERlab FX2 N synthesis module. The inhibitory potency of AG-120 was measured with a diaphorase/resazurin coupled assay using recombinant IDH1R132H or IDH1 (n=2). Internalization of [18F]AG-120 were determined in vitro using U251 human glioblastoma cells stably transfected with IDH1 or IDH1R132H [2]. In vivo metabolism was investigated in healthy CD-1 mice (n=3) by radio-chromatographic analyses of plasma and brain tissue. Dynamic PET (Mediso, nanoScan® PET/CT) imaging studies were performed in nude rats bearing U251-IDH1 (n=2) or U251-IDH1R132H (n=2) glioblastoma. Results: For the first time, diastereomerically pure [18F]AG-120 was prepared by an automated copper-mediated radiolabelling approach without azeotropic drying starting from the stanny

A hallmark of diabetes is the progressive loss of the beta-cell mass (BCM) and function. Most of the diagnostic methods for diabetes are mostly reflective of the beta-cell function, whereas current methodologies for studying the beta-cell mass are limited to post-mortem biopsies or highly invasive methods. Positron-emission tomography (PET) is a highly sensitive and quantitative medical imaging technique that was suggested as a tool for non-invasive imaging of the pancreas and quantification of the BCM. GPR44 is a membrane protein recently identified as a promising beta-cell biomarker highly expressed in beta cells, but not in other exocrine or endocrine tissues within the pancreas. Paper I describes the preclinical evaluation of the carbon-11 labeled GPR44 antagonist [11C]MK-7246 using cell lines and pigs. We have demonstrated strong binding of [11C]MK-7246 to the GPR44 receptor as well as its specificity to the pig pancreas. Based on the success of this study, we have initiated the clinical translation of [11C]MK-7246 to first-in-man BCM imaging studies in diabetic patients. As a direct continuation to paper I, paper II focused on the preclinical evaluation of MK-7246 labeled with a different isotope, namely fluorine-18. Additional characterizations were obtained such as the binding affinity and specificity to endocrine pancreatic fractions. Proof of concept in vivo GPR44 directed imaging has been demonstrated as well using an immunodeficient mouse model grafted with GPR44 expressing cells. Paper III is focused on the development and screening of first-in-class affibody molecules targeting DGCR2, another biomarker specific to beta cells. After binding and biodistribution assessments, the affibody molecule ZDGCR2:AM106 has been retained as the lead candidate for DGCR2 targeted imaging. In Paper IV, we have labeled the affibody molecule ZDGCR2:AM106 screened from paper III using fluorine-18, and the resulting [18F]ZDGCR2:AM106 has been assessed for in vivo PET ima

Biologicals gained attention over the past decades thanks to their therapeutic success especially in oncology. Positron Emission Tomography (PET) with Zirconium-89 is attractive thanks to 89Zr half-life (78.41h) matching the biological half-life of monoclonal antibodies (mAbs). We provide an overview of 89Zr-immuno-PET imaging using current and emerging radiolabeling tools and preclinical imaging to facilitate translation to the clinic of new antibody constructs. By improving the radiochemistry toolbox and better understanding quantification using preclinical PET cameras, new opportunities can be translated in the clinic. Chapter 1 introduces the current position of PET and 89Zr-immuno-PET imaging, in the context of biopharmaceuticals development while Chapter 2 gives an overview of current radiolabeling methods of biopharmaceuticals with 89Zr, 64Cu and 68Ga but also less common radiometals: 52Mn, 86Y, 66Ga, 44Sc, and 18F as in [18F]AlF. Chelator-radionuclide pairs and radiolabeling conditions are discussed along with recent preclinical and clinical trends. Chapter 3 evaluates with 89Zr-immuno-PET, CX-2009, a Probody Drug Conjugate (PDC) with a toxic DM4 payload attached. Probody® therapeutics possess antigen binding domains masked by peptide caps, only removed in the tumor environment by tumor-associated proteases, locally overexpressed. Probodies aim at widening the therapeutic window while PDCs at delivering selectively their payload to tumors via widely expressed antigens. We evaluated CX-2009 in CD166-positive lung cancer mice in comparison with its Probody, unmasked antibody drug conjugate, and parental mAb derivatives. Tumor uptake was similar for all constructs 72h p.i. demonstrating that CX-2009 can target CD166-expressing tumors and thus supporting clinical evaluation of Probody® therapeutics. In chapter 4, the novel octadentate chelator DFO* was studied in depth and compared with desferrioxamine (DFO), current standard for 89Zr-immuno-PET, DFOSq, also rep

Introduction: Traditional cancer treatments, such as chemotherapy, are often incapable of achieving complete responses as standalone therapies. Hence, current treatment strategies typically rely on a combination of several approaches. Nanoparticle-based photothermal therapy (PTT) is a technique used to kill cancer cells through localized, severe hyperthermia that has shown promise as an add-on treatment to multiple cancer therapies. Here, we evaluated whether the combination of gold nanoshell (NS)-based PTT and liposomal doxorubicin could improve outcome in a mouse model of colorectal cancer. Methods: First, NS-based PTT was performed on tumor-bearing mice. Radiolabeled liposomes were then injected at different timepoints to follow their accumulation in the tumor and determine the ideal injection time after PTT. In addition, fluorescent liposomes were used to observe the liposomal distribution in the tumor after PTT. Finally, we combined PTT and doxorubicin-loaded liposomes and studied the effect of the treatment strategy on the mice by following tumor growth and survival. Results: PTT significantly improved liposomal accumulation in the tumor, but only when the liposomes were injected immediately after the therapy. The liposomes accumulated mostly in regions adjacent to the ablated areas. When PTT was combined with liposomal doxorubicin, the mice experienced a slowdown in tumor growth and an improvement in survival. Conclusion: According to our preclinical study, NS-based PTT seems promising as an add-on treatment for liposomal chemotherapy and potentially other systemic therapies, and could be relevant for future application in a clinical setting.

A hallmark of diabetes is the progressive loss of the beta-cell mass (BCM) and function. Most of the diagnostic methods for diabetes are mostly reflective of the beta-cell function, whereas current methodologies for studying the beta-cell mass are limited to post-mortem biopsies or highly invasive methods. Positron-emission tomography (PET) is a highly sensitive and quantitative medical imaging technique that was suggested as a tool for non-invasive imaging of the pancreas and quantification of the BCM. GPR44 is a membrane protein recently identified as a promising beta-cell biomarker highly expressed in beta cells, but not in other exocrine or endocrine tissues within the pancreas. Paper I describes the preclinical evaluation of the carbon-11 labeled GPR44 antagonist [11C]MK-7246 using cell lines and pigs. We have demonstrated strong binding of [11C]MK-7246 to the GPR44 receptor as well as its specificity to the pig pancreas. Based on the success of this study, we have initiated the clinical translation of [11C]MK-7246 to first-in-man BCM imaging studies in diabetic patients. As a direct continuation to paper I, paper II focused on the preclinical evaluation of MK-7246 labeled with a different isotope, namely fluorine-18. Additional characterizations were obtained such as the binding affinity and specificity to endocrine pancreatic fractions. Proof of concept in vivo GPR44 directed imaging has been demonstrated as well using an immunodeficient mouse model grafted with GPR44 expressing cells. Paper III is focused on the development and screening of first-in-class affibody molecules targeting DGCR2, another biomarker specific to beta cells. After binding and biodistribution assessments, the affibody molecule ZDGCR2:AM106 has been retained as the lead candidate for DGCR2 targeted imaging. In Paper IV, we have labeled the affibody molecule ZDGCR2:AM106 screened from paper III using fluorine-18, and the resulting [18F]ZDGCR2:AM106 has been assessed for in vivo PET ima

Introduction: Traditional cancer treatments, such as chemotherapy, are often incapable of achieving complete responses as standalone therapies. Hence, current treatment strategies typically rely on a combination of several approaches. Nanoparticle-based photothermal therapy (PTT) is a technique used to kill cancer cells through localized, severe hyperthermia that has shown promise as an add-on treatment to multiple cancer therapies. Here, we evaluated whether the combination of gold nanoshell (NS)-based PTT and liposomal doxorubicin could improve outcome in a mouse model of colorectal cancer. Methods: First, NS-based PTT was performed on tumor-bearing mice. Radiolabeled liposomes were then injected at different timepoints to follow their accumulation in the tumor and determine the ideal injection time after PTT. In addition, fluorescent liposomes were used to observe the liposomal distribution in the tumor after PTT. Finally, we combined PTT and doxorubicin-loaded liposomes and studied the effect of the treatment strategy on the mice by following tumor growth and survival. Results: PTT significantly improved liposomal accumulation in the tumor, but only when the liposomes were injected immediately after the therapy. The liposomes accumulated mostly in regions adjacent to the ablated areas. When PTT was combined with liposomal doxorubicin, the mice experienced a slowdown in tumor growth and an improvement in survival. Conclusion: According to our preclinical study, NS-based PTT seems promising as an add-on treatment for liposomal chemotherapy and potentially other systemic therapies, and could be relevant for future application in a clinical setting.

Tucatinib is a selective human epidermal growth factor receptor 2 (HER2) tyrosine kinase inhibitor approved by the U.S. Food and Drug Administration (FDA) in April 2020 for HER2-positive lesions in metastatic breast cancer patients, including CNS metastases. In this article, we attempted to develop the first small molecule, blood–brain-barrier (BBB) penetrant HER2 PET imaging probe based on tucatinib. [11C]tucatinib was synthesized via a Stille-coupling from the respective trimethylstannyl precursor and its biodistribution was evaluated in NMRI nude mice bearing HER2-overexpressing human ovarian cancer cells (SKOV-3). No significant tumor accumulation was observed despite its high affinity for HER-2 receptors (IC50 = 6.9 nM). High liver and intestinal uptake indicate that [11C]tucatinib is too lipophilic to be used as a tumor targeting PET tracer. Therefore, chemical modifications of [11C]tucatinib are needed to increase the polarity for tumor imaging. Tucatinib as an FDA approved drug is still an interesting platform to develop the first small molecule HER2-selective PET tracer. The study highlights the differences between a drug, which needs to be effective, and an imaging agent, which is dependent on contrast.

Simple Summary Prostate cancer continues to be the most frequently diagnosed form of cancer and the leading cause of cancer-related deaths among men. For a successful treatment plan and outcome, an early diagnosis, correct staging, and monitoring of treatment response are crucial. To improve this, a radiotracer could be used to target the two most abundant proteins overexpressed in prostate cancer: prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR). To date, no such heterodimeric radiotracer is used in the clinic. In this study, we have preclinically characterized and evaluated a galium-68 labelled PSMA/GRPR-targeting radiotracer for PET imaging of prostate cancer. We hope that the findings from this study will be able to contribute to designing better heterodimeric ligands, promote clinical translation of a heterodimer, and serve as a step towards a first-in-human study. The development of radioligands targeting prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR) has shown promising results for the imaging and therapy of prostate cancer. However, studies have shown that tumors and metastases can express such targets heterogeneously. To overcome this issue and to improve protein binding, radioligands with the ability to bind both PSMA and GRPR have been developed. Herein, we present the preclinical characterization of [Ga-68]Ga-BQ7812; a PSMA/GRPR-targeting radioligand for the diagnostic PET imaging of prostate cancer. This study aimed to evaluate [Ga-68]Ga-BQ7812 to promote the translation of such imaging probes into the clinic. [Ga-68]Ga-BQ7812 demonstrated rapid and specific binding to both targets in a PSMA/GRPR-expressing PC3-pip cell line. Results from the biodistribution study in PC3-pip xenografted mice showed specific binding to both targets, with the highest activity uptake at 1 h pi in tumor (PSMA+/GRPR+, 10.4 +/- 1.0% IA/g), kidneys (PSMA+, 45 +/- 16% IA/g), and pancreas (GRPR+, 5.6, De två första författarna delar förstaförfattarskapet.

Inflammation is our body’s sophisticated defense mechanism against invading pathogens, traumas, and tumors. Repeatable and non-invasive monitoring of inflammation process would open opportunities to improve our knowledge of several diseases and enable assessment of personalized treatments. Positron emission tomography (PET) combined with computed tomography (CT) has sufficient sensitivity to visualize the location of inflamed tissue in minimally invasive way. Paper I focused utilizing an already clinically available radiotracer [68Ga]Ga-DOTA-TATE as a macrophage marker for PET imaging in porcine and rodent models of pulmonary inflammation. In Paper II novel radiotracer [11C]GW457427 was evaluated as marker for neutrophil elastase expression in a large animal model of acute respiratory distress syndrome. In Paper III the most favorable Affibody molecule conjugate for SPECT and PET imaging of CD69 expression of activated immune cells was selected. Paper IV followed the results from Paper III and compared the uptake of [68Ga]Ga-DOTA-ZCAM241with a negative control Affibody molecule conjugate [68Ga]Ga-DOTA-ZAM106 in rheumatoid arthritis mouse model. [68Ga]Ga-DOTA-TATE had increased SUV uptake in the most damaged parts of the lungs in porcine lavage model, that corresponded with the results from CT images and quantification, histology staining and [18F]FDG uptake in Paper I . On the rat lung inflammation model the [68Ga]Ga-DOTA-TATE uptake was significantly increased in the damaged lungs compared with healthy control group. The uptake could also be blocked in vivo. Paper II demonstrated that the binding of the neutrophil elastase radiotracer [11C]GW457427 was specific and selective in vivo. SUV were especially elevated in damaged lung regions and neutrophil rich tissues bone marrow and spleen. Paper III indicated that the Affibody molecule variant ZCAM241 had the highest affinity for human and murine CD69 as well as the lowest background binding in SPECT images and was c

Inflammation is our body’s sophisticated defense mechanism against invading pathogens, traumas, and tumors. Repeatable and non-invasive monitoring of inflammation process would open opportunities to improve our knowledge of several diseases and enable assessment of personalized treatments. Positron emission tomography (PET) combined with computed tomography (CT) has sufficient sensitivity to visualize the location of inflamed tissue in minimally invasive way. Paper I focused utilizing an already clinically available radiotracer [68Ga]Ga-DOTA-TATE as a macrophage marker for PET imaging in porcine and rodent models of pulmonary inflammation. In Paper II novel radiotracer [11C]GW457427 was evaluated as marker for neutrophil elastase expression in a large animal model of acute respiratory distress syndrome. In Paper III the most favorable Affibody molecule conjugate for SPECT and PET imaging of CD69 expression of activated immune cells was selected. Paper IV followed the results from Paper III and compared the uptake of [68Ga]Ga-DOTA-ZCAM241with a negative control Affibody molecule conjugate [68Ga]Ga-DOTA-ZAM106 in rheumatoid arthritis mouse model. [68Ga]Ga-DOTA-TATE had increased SUV uptake in the most damaged parts of the lungs in porcine lavage model, that corresponded with the results from CT images and quantification, histology staining and [18F]FDG uptake in Paper I . On the rat lung inflammation model the [68Ga]Ga-DOTA-TATE uptake was significantly increased in the damaged lungs compared with healthy control group. The uptake could also be blocked in vivo. Paper II demonstrated that the binding of the neutrophil elastase radiotracer [11C]GW457427 was specific and selective in vivo. SUV were especially elevated in damaged lung regions and neutrophil rich tissues bone marrow and spleen. Paper III indicated that the Affibody molecule variant ZCAM241 had the highest affinity for human and murine CD69 as well as the lowest background binding in SPECT images and was c

Introduction: Traditional cancer treatments, such as chemotherapy, are often incapable of achieving complete responses as standalone therapies. Hence, current treatment strategies typically rely on a combination of several approaches. Nanoparticle-based photothermal therapy (PTT) is a technique used to kill cancer cells through localized, severe hyperthermia that has shown promise as an add-on treatment to multiple cancer therapies. Here, we evaluated whether the combination of gold nanoshell (NS)-based PTT and liposomal doxorubicin could improve outcome in a mouse model of colorectal cancer. Methods: First, NS-based PTT was performed on tumor-bearing mice. Radiolabeled liposomes were then injected at different timepoints to follow their accumulation in the tumor and determine the ideal injection time after PTT. In addition, fluorescent liposomes were used to observe the liposomal distribution in the tumor after PTT. Finally, we combined PTT and doxorubicin-loaded liposomes and studied the effect of the treatment strategy on the mice by following tumor growth and survival. Results: PTT significantly improved liposomal accumulation in the tumor, but only when the liposomes were injected immediately after the therapy. The liposomes accumulated mostly in regions adjacent to the ablated areas. When PTT was combined with liposomal doxorubicin, the mice experienced a slowdown in tumor growth and an improvement in survival. Conclusion: According to our preclinical study, NS-based PTT seems promising as an add-on treatment for liposomal chemotherapy and potentially other systemic therapies, and could be relevant for future application in a clinical setting.

Tucatinib is a selective human epidermal growth factor receptor 2 (HER2) tyrosine kinase inhibitor approved by the U.S. Food and Drug Administration (FDA) in April 2020 for HER2-positive lesions in metastatic breast cancer patients, including CNS metastases. In this article, we attempted to develop the first small molecule, blood–brain-barrier (BBB) penetrant HER2 PET imaging probe based on tucatinib. [11C]tucatinib was synthesized via a Stille-coupling from the respective trimethylstannyl precursor and its biodistribution was evaluated in NMRI nude mice bearing HER2-overexpressing human ovarian cancer cells (SKOV-3). No significant tumor accumulation was observed despite its high affinity for HER-2 receptors (IC50 = 6.9 nM). High liver and intestinal uptake indicate that [11C]tucatinib is too lipophilic to be used as a tumor targeting PET tracer. Therefore, chemical modifications of [11C]tucatinib are needed to increase the polarity for tumor imaging. Tucatinib as an FDA approved drug is still an interesting platform to develop the first small molecule HER2-selective PET tracer. The study highlights the differences between a drug, which needs to be effective, and an imaging agent, which is dependent on contrast.

Prostate-specific membrane antigen (PSMA) binding tracers are promising agents for the targeting of prostate tumors. To further optimize the clinically established radiopharmaceutical PSMA-617, novel PSMA ligands for prostate cancer endoradiotherapy were developed. A series of PSMA binding tracers that comprise a benzyl group at the chelator moiety were obtained by solid-phase synthesis. The compounds were labeled with 68Ga or 177Lu. Competitive cell-binding assays and internalization assays were performed using the cell line C4-2, a subline of the PSMA positive cell line LNCaP (human lymph node carcinoma of the prostate). Positron emission tomography (PET) imaging and biodistribution studies were conducted in a C4-2 tumor bearing BALB/c nu/nu mouse model. All 68Ga-labeled ligands were stable in human serum over 2 h; 177Lu-CA030 was stable over 72 h. The PSMA ligands revealed inhibition potencies [Ki] (equilibrium inhibition constants) between 4.8 and 33.8 nM. The percentage of internalization of the injected activity/10^6 cells of 68Ga-CA028, 68Ga-CA029, and 68Ga-CA030 was 41.2 ± 2.7, 44.3 ± 3.9, and 53.8 ± 5.4, respectively; for the comparator 68Ga-PSMA-617, 15.5 ± 3.1 was determined. Small animal PET imaging of the compounds showed a high tumor-to-background contrast. Organ distribution studies revealed high specific uptake in the tumor, that is, approximately 34.4 ± 9.8% of injected dose per gram (%ID/g) at 1 h post injection for 68Ga-CA028. At 1 h p.i., 68Ga-CA028 and 68Ga-CA030 demonstrated lower kidney uptake than 68Ga-PSMA-617, but at later time points, kidney time-activity curves converge. In line with the preclinical data, first diagnostic PET imaging using 68Ga-CA028 and 68Ga-CA030 revealed high-contrast detection of bone and lymph node lesions in patients with metastatic prostate cancer. The novel PSMA ligands, in particular CA028 and CA030, are promising agents for targeting PSMA-positive tumor lesions as shown in the preclinical evaluation and in a fir

Fibroblast activation protein (FAP), mainly expressed by cancer-associated fibroblasts (CAFs) in the tumour stroma, promotes tumour growth, metastasis, and immunosuppression and, therefore, has been studied as a target for cancer diagnosis and treatment. With regard to immunotherapy, the innovative modular universal CAR (UniCAR) platform developed by our group is one of the most promising approach due to the reduced risk for e.g. on-target/off-tumour toxicities and cytokine release syndrome. Thereby, chimeric antigen receptor (CAR) T-cells (UniCAR T cells) are exclusively activated in the presence of a target module (TM) that specifically establishes the crosslinking between target cells and UniCAR T-cells. FAP specific TMs are hypothesized to be not only immunotherapeutics with increased safety but in addition to be suitable as radionuclide-based theranostic agents. For that, low molecular weight TMs that are rapidly eliminated allowing a specific and recurrent on/off switch of UniCAR T-cell activity via TM dosing were developed by fusion of the single-chain variable fragment (scFv) of an anti-human FAP mAb to the peptide epitope E5B9 that is recognized by the UniCAR T-cells. To ease the clinical TM administration at later stages of tumour therapy and for targeted radionuclide therapy, however, TMs with extended half-life may be advantageous. Therefore, anti-FAP TMs based on the human IgG4 Fc-domain, including a mutated version, were created. All TMs were tested (i) in vitro based on naturally and artificially overexpressing 2D and 3D models and (ii) in vivo by positron emission tomography (PET) and single-photon emission tomography (SPECT) in NMRI nude mice bearing both mock transfected and FAP overexpressing HT1080 tumor xenografts. In vitro, all TMs were proven to specifically redirect UniCAR T-cells to FAP-expressing target cells. Moreover, FAP specific TMs could be conjugated to different chelators, e.g. Bispidines, NODAGA, and CHX-A-DTPA and, afterwards, radi

Epidermal growth factor receptor (EGFR) is overexpressed in many malignancies. EGFR-targeted therapy extends survival of patients with disseminated cancers. Radionuclide molecular imaging of EGFR expression would make EGFR-directed treatment more personalized and therefore more efficient. A previous study demonstrated that affibody molecule [68Ga]Ga-DFO-ZEGFR:2377 permits specific positron-emission tomography (PET) imaging of EGFR expression in xenografts at 3 h after injection. We anticipated that imaging at 24 h after injection would provide higher contrast, but this is prevented by the short half-life of 68Ga (67.6 min). Here, we therefore tested the hypothesis that the use of the non-conventional long-lived positron emitter 66Ga (T1/2 = 9.49 h, β+ = 56.5%) would permit imaging with higher contrast. 66Ga was produced by the 66Zn(p,n)66Ga nuclear reaction and DFO-ZEGFR:2377 was efficiently labelled with 66Ga with preserved binding specificity in vitro and in vivo. At 24 h after injection, [66Ga]Ga-DFO-ZEGFR:2377 provided 3.9-fold higher tumor-to-blood ratio and 2.3-fold higher tumor-to-liver ratio than [68Ga]Ga-DFO-ZEGFR:2377 at 3 h after injection. At the same time point, [66Ga]Ga-DFO-ZEGFR:2377 provided 1.8-fold higher tumor-to-blood ratio, 3-fold higher tumor-to-liver ratio, 1.9-fold higher tumor-to-muscle ratio and 2.3-fold higher tumor-to-bone ratio than [89Zr]Zr-DFO-ZEGFR:2377. Biodistribution data were confirmed by whole body PET combined with magnetic resonance imaging (PET/MRI). The use of the positron emitter 66Ga for labelling of DFO-ZEGFR:2377 permits PET imaging of EGFR expression at 24 h after injection and improves imaging contrast.

Epidermal growth factor receptor (EGFR) is overexpressed in many malignancies. EGFR-targeted therapy extends survival of patients with disseminated cancers. Radionuclide molecular imaging of EGFR expression would make EGFR-directed treatment more personalized and therefore more efficient. A previous study demonstrated that affibody molecule [68Ga]Ga-DFO-ZEGFR:2377 permits specific positron-emission tomography (PET) imaging of EGFR expression in xenografts at 3 h after injection. We anticipated that imaging at 24 h after injection would provide higher contrast, but this is prevented by the short half-life of 68Ga (67.6 min). Here, we therefore tested the hypothesis that the use of the non-conventional long-lived positron emitter 66Ga (T1/2 = 9.49 h, β+ = 56.5%) would permit imaging with higher contrast. 66Ga was produced by the 66Zn(p,n)66Ga nuclear reaction and DFO-ZEGFR:2377 was efficiently labelled with 66Ga with preserved binding specificity in vitro and in vivo. At 24 h after injection, [66Ga]Ga-DFO-ZEGFR:2377 provided 3.9-fold higher tumor-to-blood ratio and 2.3-fold higher tumor-to-liver ratio than [68Ga]Ga-DFO-ZEGFR:2377 at 3 h after injection. At the same time point, [66Ga]Ga-DFO-ZEGFR:2377 provided 1.8-fold higher tumor-to-blood ratio, 3-fold higher tumor-to-liver ratio, 1.9-fold higher tumor-to-muscle ratio and 2.3-fold higher tumor-to-bone ratio than [89Zr]Zr-DFO-ZEGFR:2377. Biodistribution data were confirmed by whole body PET combined with magnetic resonance imaging (PET/MRI). The use of the positron emitter 66Ga for labelling of DFO-ZEGFR:2377 permits PET imaging of EGFR expression at 24 h after injection and improves imaging contrast.

Epidermal growth factor receptor (EGFR) is overexpressed in many malignancies. EGFR-targeted therapy extends survival of patients with disseminated cancers. Radionuclide molecular imaging of EGFR expression would make EGFR-directed treatment more personalized and therefore more efficient. A previous study demonstrated that affibody molecule [68Ga]Ga-DFO-ZEGFR:2377 permits specific positron-emission tomography (PET) imaging of EGFR expression in xenografts at 3 h after injection. We anticipated that imaging at 24 h after injection would provide higher contrast, but this is prevented by the short half-life of 68Ga (67.6 min). Here, we therefore tested the hypothesis that the use of the non-conventional long-lived positron emitter 66Ga (T1/2 = 9.49 h, β+ = 56.5%) would permit imaging with higher contrast. 66Ga was produced by the 66Zn(p,n)66Ga nuclear reaction and DFO-ZEGFR:2377 was efficiently labelled with 66Ga with preserved binding specificity in vitro and in vivo. At 24 h after injection, [66Ga]Ga-DFO-ZEGFR:2377 provided 3.9-fold higher tumor-to-blood ratio and 2.3-fold higher tumor-to-liver ratio than [68Ga]Ga-DFO-ZEGFR:2377 at 3 h after injection. At the same time point, [66Ga]Ga-DFO-ZEGFR:2377 provided 1.8-fold higher tumor-to-blood ratio, 3-fold higher tumor-to-liver ratio, 1.9-fold higher tumor-to-muscle ratio and 2.3-fold higher tumor-to-bone ratio than [89Zr]Zr-DFO-ZEGFR:2377. Biodistribution data were confirmed by whole body PET combined with magnetic resonance imaging (PET/MRI). The use of the positron emitter 66Ga for labelling of DFO-ZEGFR:2377 permits PET imaging of EGFR expression at 24 h after injection and improves imaging contrast.

This thesis focused on the value of different positron emission tomography (PET) imaging techniques visualizing targets and targeted anticancer therapies for future treatment tailoring. As a general introduction, chapter 1 provides an overview of the available literature on molecular imaging with PET for the improvement of personalized cancer care. Part I of this thesis focusses on visualizing targets: estrogen receptor (ER) and androgen receptor (AR) imaging in patients with breast cancer. Approximately 75% of the patients with breast cancer have an ER-positive tumor. The success rate of endocrine therapy relies heavily on the ER expression of the tumor. Recently, also AR expression emerged as a possible target of therapy, because it is present in 70–80% of the patients with breast cancer. In chapter 2, [18F]fluoroestradiol ([18F]FES) PET and [18F]fluorodihydrotestosterone ([18F]FDHT) PET are evaluated to assess whether uptake correlates with the levels of ER and AR expression in simultaneous biopsied metastases. In chapter 3, the interobserver variability in visual and quantitative assessment of [18F]FES and [18F]FDHT PET are determined, because reliable, observer- independent evaluation is necessary for application of these new techniques in clinical practice. Part II concerns strategies to optimize treatment with the targeted anticancer drug sorafenib, a small molecule protein kinase inhibitor. Sorafenib has activity against multiple targets involved in the growth, angiogenesis and spread of cancer including C-RAF, B-RAF, mutant B-RAF, vascular endothelial growth factor receptors 1, 2 and 3, platelet-derived growth factor receptor β, FMS-like tyrosine kinase 3, c-Kit protein and RET receptor tyrosine kinase. Sorafenib has been approved for treatment of locally advanced and metastatic hepatocellular carcinoma, renal cell carcinoma and iodine-refractory differentiated thyroid carcinoma at a standard fixed dose of 400 mg twice daily in a continuous schedule. Curren

While methods for early detection and risk stratification of prostate cancer (PCa) have greatly improved in recent years, there remains an unmet clinical need for improved methods to accurately detect and grade PCa non-invasively using imaging techniques. Zinc (Zn) has been studied as a target biomarker due to its unique physiology in the prostate. It accumulates in a healthy prostate to a remarkable high concentration, while it significantly decreases by 60-80% in de-differentiated PCa. Previous studies have examined this property as a potential biomarker for using imaging modalities such as MRI and fluorescence to characterize PCa, however, these techniques are not amenable to clinical translation. PET imaging has yet to be explored in detecting Zn for a tool of PCa diagnosis. This study focused on developing a novel probe, 18F-labelled Tris(2-pyridylmethyl)amine-based (18F-TPA), which exhibits excellent zinc specificity and targetability, cell membrane permeability, and low cytotoxicity. Once the cells uptake the radionuclides, they bind with intracellular free zinc ion and will not flux out of the cells. Thus, the 18F-TPA PET imaging method could directly image zinc biodistribution and therefore be applied to detect alterations in zinc homeostasis in PCa and other diseases. Methods: This project started from the chemical synthesis of a precursor compound NO2-TPA and a non-radioactive reference compound, 19F-TPA for the subsequent synthesis and characterization of radioactive 18F-TPA. 18F-TPA was synthesized in a hot cell with NO2-TPA reacting 18F in the presence of kryptofix 222 and purified using semi-prep HPLC with the conditions determined by the co-injection of NO2-TPA and 19F-TPA. The quality of 18F-TPA was ensured by co-injection with 19F-TPA to an analytical HPLC showing the same retention time. Furthermore, 19F-TPA was used to characterize Zn binding by determining a Zn19F-TPA complex formation on an analytical HPLC. Subsequently the developed probe was

Purpose: Recent clinical successes in the use of chimeric antigen receptor (CAR) T cell therapy has revolutionized cancer therapy. However, only 20% to 30% of patients achieve long term survival benefits, and distinguishing responders from non-responders early remains a challenge with conventional imaging techniques. Thus, there is an urgent need to develop new biomarkers to distinguish responsive and resistant patients, both to improve standard of care and to assess the antitumor activity of experimental immunotherapies. This study aims to determine the efficacy of a novel granzyme activated imaging probe to image treatment response to CAR T cell therapy in a mouse model.Methods: Immunodeficient mice were obtained and inoculated subcutaneously with Raji tumors. CD8+ T cells were obtained from donor blood and transduced to express anti-CD19 receptors. CAR T cells were then expanded in vitro with IL-2. After tumors were palpable, mice were treated with empty or anti-CD19 CAR T cells intravenously. Mice were then injected with 64Cu-GRIP B at 24 hours post CAR T cell administration. PET/CT studies were performed on a dedicated Inveon small animal scanner. Post mortem radiotracer uptake was quantified as %injected dose/g (%ID/g) values for tumor and normal tissue. Tumors from one representative animal per group was prepared for autoradiography. Results: ROI analysis of static PET/CT images indicated that 64Cu-GRIP B uptake in treated tumors rose from 0.5 to 2 hours post injection. Tumoral uptake of the probe was higher in anti-CD19 CAR T versus vehicle treated arm at 2 hours post injection. The mean tumoral standard uptake values for anti-CD19 CAR T and vehicle arms were 1.5%ID/cc and 0.4%ID/cc, respectively. Biodistribution data demonstrated similar uptake of the 64Cu-GRIP B probe between treatment arms as mean %ID/g for both arms was roughly 0.75. Digital autoradiography suggested substantially higher and localized uptake of the probe in the treatment arm compared to

Purpose: Recent clinical successes in the use of chimeric antigen receptor (CAR) T cell therapy has revolutionized cancer therapy. However, only 20% to 30% of patients achieve long term survival benefits, and distinguishing responders from non-responders early remains a challenge with conventional imaging techniques. Thus, there is an urgent need to develop new biomarkers to distinguish responsive and resistant patients, both to improve standard of care and to assess the antitumor activity of experimental immunotherapies. This study aims to determine the efficacy of a novel granzyme activated imaging probe to image treatment response to CAR T cell therapy in a mouse model.Methods: Immunodeficient mice were obtained and inoculated subcutaneously with Raji tumors. CD8+ T cells were obtained from donor blood and transduced to express anti-CD19 receptors. CAR T cells were then expanded in vitro with IL-2. After tumors were palpable, mice were treated with empty or anti-CD19 CAR T cells intravenously. Mice were then injected with 64Cu-GRIP B at 24 hours post CAR T cell administration. PET/CT studies were performed on a dedicated Inveon small animal scanner. Post mortem radiotracer uptake was quantified as %injected dose/g (%ID/g) values for tumor and normal tissue. Tumors from one representative animal per group was prepared for autoradiography. Results: ROI analysis of static PET/CT images indicated that 64Cu-GRIP B uptake in treated tumors rose from 0.5 to 2 hours post injection. Tumoral uptake of the probe was higher in anti-CD19 CAR T versus vehicle treated arm at 2 hours post injection. The mean tumoral standard uptake values for anti-CD19 CAR T and vehicle arms were 1.5%ID/cc and 0.4%ID/cc, respectively. Biodistribution data demonstrated similar uptake of the 64Cu-GRIP B probe between treatment arms as mean %ID/g for both arms was roughly 0.75. Digital autoradiography suggested substantially higher and localized uptake of the probe in the treatment arm compared to

While methods for early detection and risk stratification of prostate cancer (PCa) have greatly improved in recent years, there remains an unmet clinical need for improved methods to accurately detect and grade PCa non-invasively using imaging techniques. Zinc (Zn) has been studied as a target biomarker due to its unique physiology in the prostate. It accumulates in a healthy prostate to a remarkable high concentration, while it significantly decreases by 60-80% in de-differentiated PCa. Previous studies have examined this property as a potential biomarker for using imaging modalities such as MRI and fluorescence to characterize PCa, however, these techniques are not amenable to clinical translation. PET imaging has yet to be explored in detecting Zn for a tool of PCa diagnosis. This study focused on developing a novel probe, 18F-labelled Tris(2-pyridylmethyl)amine-based (18F-TPA), which exhibits excellent zinc specificity and targetability, cell membrane permeability, and low cytotoxicity. Once the cells uptake the radionuclides, they bind with intracellular free zinc ion and will not flux out of the cells. Thus, the 18F-TPA PET imaging method could directly image zinc biodistribution and therefore be applied to detect alterations in zinc homeostasis in PCa and other diseases. Methods: This project started from the chemical synthesis of a precursor compound NO2-TPA and a non-radioactive reference compound, 19F-TPA for the subsequent synthesis and characterization of radioactive 18F-TPA. 18F-TPA was synthesized in a hot cell with NO2-TPA reacting 18F in the presence of kryptofix 222 and purified using semi-prep HPLC with the conditions determined by the co-injection of NO2-TPA and 19F-TPA. The quality of 18F-TPA was ensured by co-injection with 19F-TPA to an analytical HPLC showing the same retention time. Furthermore, 19F-TPA was used to characterize Zn binding by determining a Zn19F-TPA complex formation on an analytical HPLC. Subsequently the developed probe was

[EN] Several research groups are studying organ-dedicated limited angle positron emission tomography (PET) systems to optimize performance-cost ratio, sensitivity, access to the patient, and/or flexibility. Often open systems are considered, typically consisting of two detector panels of various sizes. Such systems provide incomplete sampling due to limited angular coverage and/or truncation, which leads to artifacts in the reconstructed activity images. In addition, these organ-dedicated PET systems are usually stand-alone systems, and as a result, no attenuation information can be obtained from anatomical images acquired in the same imaging session. It has been shown that the use of time-of-flight (TOF) information reduces incomplete data artifacts and enables the joint estimation of the activity and the attenuation factors. In this work, we explore with simple 2-D simulations the performance and stability of a joint reconstruction algorithm, for imaging with a limited angle PET system. The reconstruction is based on the so-called maximum-likelihood attenuation correction factors (MLACF) algorithm and uses linear attenuation coefficients in a known-tissue-class region to obtain absolute quantification. Different panel sizes and different TOF resolutions are considered. The noise propagation is compared to that of MLEM reconstruction with exact attenuation correction (AC) for the same PET system. The results show that with good TOF resolution, images of good visual quality can be obtained. If also a good scatter correction can be implemented, quantitative PET imaging will be possible. Further research, in particular on scatter correction, is required.