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We report herein an efficient and fully automated protocol for the radiosynthesis of [18 F]FAPI-74, a new positron emission tomography (PET) radiopharmaceutical for in vivo detection of the fibroblast activation protein. [18 F]FAPI-74 was synthesized via a rapid [18 F]aluminum fluoride coordination reaction, which was first developed on the flexible GE TRACERLab FX2N (FXN) platform and later translated to the cassette-based module Trasis AllInOne (AIO). The results obtained with both modules were comparable in terms of yield and reproducibility. Automation of [18 F]FAPI-74 radiosynthesis on the FXN was carried out in 35 min with a radiochemical yield (RCY) of 18.5 ± 2.5% (n = 5, relative to starting [18 F]fluoride). Method transfer to the AIO platform following minor optimizations allowed for the production of [18 F]FAPI-74 in an isolated RCY of 20 ± 2.5% [n = 3] with an overall synthesis time of 40 min. The radiochemical purity was greater than 95% for [18 F]FAPI-74, obtained from both modules. Overall, the protocol reliably provides a sterile and pyrogen-free good manufacturing practice (GMP) compliant product of [18 F]FAPI-74 suitable for clinical PET imaging.

By using solid targets in medical cyclotrons, it is possible to produce large amounts of 68GaCl3. Purification of Ga3+ from metal ion impurities is a critical step, as these metals compete with Ga3+ in the complexation with different chelators, which negatively affects the radiolabeling yields. In this work, we significantly lowered the level of iron (Fe) impurities by adding ascorbate in the purification, and the resulting 68GaCl3could be utilized for high-yield radiolabeling of clinically relevant DOTA-based tracers. 68GaCl3 was cyclotron-produced and purified with ascorbate added in the wash solutions through the UTEVA resins. The 68Ga eluate was analyzed for radionuclidic purity (RNP) by gamma spectroscopy, metal content by ICP-MS, and by titrations with the chelators DOTA, NOTA, and HBED. The 68GaCl3eluate was utilized for GMP-radiolabeling of the DOTA-based tracers DOTATOC and FAPI-46 using an automated synthesis module. DOTA chelator titrations gave an apparent molar activity (AMA) of 491 ± 204 GBq/µmol. GMP-compliant syntheses yielded up to 7 GBq/batch [68Ga]Ga-DOTATOC and [68Ga]Ga-FAPI-46 (radiochemical yield, RCY ~ 60%, corresponding to ten times higher compared to generator-based productions). Full quality control (QC) of 68Ga-labelled tracers showed radiochemically pure and stable products at least four hours from end-of-synthesis.

The growing need and limited availability of generator produced 68Ga (T1/2 = 68 min) for PET has provided the impetus for alternative, high output, 68Ga production routes such as charge particle activation of enriched 68Zn using PET cyclotrons. The work presents a rapid production method for clinically useful 68Ga for radiolabeling. The focus is also to expand the production capacity of cyclotron solid target-produced 68Ga over generator produced and liquid solutions targets by using enriched 68Zn-foils that minimizes target preparation.

Glioblastoma multiforme (GBM) is the most common and most severe form of malignant gliomas. The prognosis is poor with current combinations of pharmaceutical, radiotherapy, and surgical therapy. A continuous search for new treatments has therefore been ongoing for many years. Therapy with tumor-infiltrating lymphocytes (TILs) is a clinically promising strategy to treat various cancers, including GBM. An endovascular intraarterial injection of TILs as a method of delivery may, instead of intravenous infusion, result in better retention of effector cells within the tumor. Prior to clinical trials of intra-arterial injections with any cells, preclinical safety data with special emphasis on embolic–ischemic events are necessary to obtain. We used native rabbits as a model for intra-arterial injections with routine clinical catheter material and a clinical angiography suite. We selectively infused a total dose of 20 million activated T cells at a cell concentration of 4,000 cells/ml over 8 min of injection time. The rabbits were evaluated for ischemic lesions by 9.4 T magnetic resonance imaging (MRI) ( n = 6), and for tracking of injected cells, single-photon emission computed tomography/computed tomography (SPECT/CT) was used ( n = 2). In this study, we show that we can selectively infuse activated T cells to a CNS volume of 3.5 cm3 (estimated from the volumetric MRI) without catastrophic embolic– ischemic adverse events. We had one adverse event with a limited basal ganglia infarction, probably due to catheter-induced mechanical occlusion of one of the lateral lenticulostriatal arteries. The cells pass through the native brain without leaving SPECT signals. The cells then, over the first hours, end up in the liver to a large extent and to a lesser degree by the spleen, pancreas, and kidneys. Virtually no uptake could be detected in the lungs. This indicates a difference in biodistribution as opposed to other cell types when infused intravenously.

Placenta-derived decidua stromal cells (DSCs) are being investigated as an alternative to other sources of mesenchymal stromal cells (MSCs) for cellular therapy. DSCs are more effective in treating acute inflammatory diseases in human and this is our preclinical safety study of human DSCs in Sprague-Dawley rats and Balb/c mice. Human DSCs were cultured and expanded from fetal membranes obtained from placentas following cesarean section. In rats, 0.5 × 106 cells/kg were injected intravenously (n = 4) or intra-aortal (n = 4). In mice, DSCs were given intravenously at doses ranging from 4-40 × 106 cells/kg (total of n = 120 mice). In vivo tracking of human cells in mice was performed by using transduced DSC with luciferin gene, and in rats by using 18F-FDG PET. Clotting parameters were determined in vitro and in vivo. All intra-arterially DSC-treated rats had normal motility and behavior and histological examination was normal for liver, spleen kidneys and thigh muscles. Mice treated with DSCs showed no immediate or long-term side effects. None of the mice died or showed acute toxicity or adverse reactions 3 and 30 days after DSC infusion. Murine blood biochemistry profiles related to liver, kidney, heart, and inflammatory indices was not influenced by DSC infusion and complete blood counts were normal. In vivo tracking of infused DSCs detected a signal in the lungs for up to 4 days post infusion. Compared to bone marrow derived MSCs, the DSCs had better viability, smaller size, but stronger clotting in human blood and plasma. Both MSC- and DSC-induced coagulation and complement activation markers, thrombin-anti-thrombin complex (TAT) and C3a, and in vitro clotting parameters were decreased by heparin supplementation. In conclusion, DSCs are safe with almost no side effects even with doses 40 times higher than are used clinically, particularly when supplemented with low-dose heparin.

Selective administration of mesenchymal stromal cells to the mesenteric arteries is a potential technique to overcome pulmonary trapping and increase the density of transplanted cells in extensive mural inflammation of the intestine, such as in inflammatory bowel disease and graft-versus-host disease. We injected 5 × 106 111In-oxine-labeled human decidual stromal cells (DSCs) to the rabbit superior mesenteric artery (SMA) using clinical routine catheters guided by an angiographical system under sterile conditions. We used longitudinal single-photon emission tomography at 6 h and at 1, 2, and 5 days to assess trafficking and distribution of DSCs. We used digital subtraction angiography, computed tomography, and hematoxylin and eosin stainings to determine biodistribution of cells and to assess safety end points. We found that selective injection of human DSCs to the rabbit SMA does not result in acute embolic complications. Furthermore, we found that IV administration resulted in extensive retention of the radiolabeled DSCs in the lungs, corroborating previous studies on pulmonary trapping. In sharp contrast, selective injections to the SMA resulted in uptake distributed in the intestine supplied by the SMA and in the liver, indicating that this approach could significantly increase the fraction of injected DSCs reaching the target tissue.

The in vivo response to lipopolysaccharide (LPS) occurs rapidly and has profound physiological and metabolic effects. The hypoxia inducible (HIF) transcription factor is an intrinsic and essential part of inflammation, and is induced by LPS. To determine the importance of the HIF response in regulating metabolism following an LPS response, glucose uptake was quantified in a time dependent manner in mice lacking HIF-1α in myeloid cells. We found that deletion of HIF-1α has an acute protective effect on LPS-induced hypoglycemia. Furthermore, reduced glucose uptake was observed in the heart and brown fat, in a time dependent manner, following loss of HIF-1α. To determine the physiological significance of these findings, cardiovascular, body temperature, and blood pressure changes were subsequently quantified in real time using radiotelemetry measurements. These studies reveal the temporal aspects of HIF-1α as a regulator of the metabolic response to acute LPS-induced inflammation.

Background The goal of the study was to assess the potential of the vascular endothelial growth factor receptor (VEGFR)-2-targeting carbon-11 labeled (R)-N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolineamine ((R)-[11C]PAQ) as a positron emission tomography (PET) imaging biomarker for evaluation of the efficacy of anticancer drugs in preclinical models. Methods MMTV-PyMT mice were treated with vehicle alone (VEH), murine anti-VEGFA antibody (B20-4.1.1), and paclitaxel (PTX) in combination or as single agents. The treatment response was measured with (R)-[11C]PAQ PET as standardized uptake value (SUV)mean, SUVmax relative changes at the baseline (day 0) and follow-up (day 4) time points, and magnetic resonance imaging (MRI)-derived PyMT mammary tumor volume (TV) changes. Expression of Ki67, VEGFR-2, and CD31 in tumor tissue was determined by immunohistochemistry (IHC). Non-parametric statistical tests were used to evaluate the relation between (R)-[11C]PAQ radiotracer uptake and therapy response biomarkers. Results The (R)-[11C]PAQ SUVmax in tumors was significantly reduced after 4 days in the B20-4.1.1/PTX combinational and B20-4.1.1 monotherapy groups (p