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Cellular therapies with cardiomyocytes produced from induced pluripotent stem cells (iPSC-CMs) offer a potential route to cardiac regeneration as a treatment for chronic ischemic heart disease. Here, we report successful long-term engraftment and in vivo maturation of autologous iPSC-CMs in two rhesus macaques with small, subclinical chronic myocardial infarctions, all without immunosuppression. Longitudinal positron emission tomography imaging using the sodium/iodide symporter (NIS) reporter gene revealed stable grafts for over 6 and 12 months, with no teratoma formation. Histological analyses suggested capability of the transplanted iPSC-CMs to mature and integrate with endogenous myocardium, with no sign of immune cell infiltration or rejection. By contrast, allogeneic iPSC-CMs were rejected within 8 weeks of transplantation. This study provides the longest-term safety and maturation data to date in any large animal model, addresses concerns regarding neoantigen immunoreactivity of autologous iPSC therapies, and suggests that autologous iPSC-CMs would similarly engraft and mature in human hearts., Competing Interests: Declaration of interests Some of these experiments were performed while D.S.N. and C.E.M. were employees of, and K. Nakamura was an advisor to, Sana Biotechnology. D.S.N. and C.E.M. are equity holders in Sana Biotechnology., (Published by Elsevier Inc.)

Objectives: Complementing the extensive research literature demonstrating that increased alcohol outlet density is associated with excessive alcohol consumption and related harms, this article synthesizes information on the types of alcohol outlet density restrictions in US state-level laws., Design: Statutes and regulations related to alcohol outlet density in all 50 states and the District of Columbia in effect as of January 1, 2022, were collected using Westlaw. State-level density restrictions were coded according to 4 variables and overlaid with existing research on state-specific local authority to regulate outlet density. Alcohol outlet density laws in Michigan and Massachusetts were analyzed in detail as case studies., Setting: United States., Main Outcome Measure: US state-level licensing laws restricting alcohol outlet density., Results: Thirty-three states and the District of Columbia have state-level licensing laws that limit alcohol outlet density. Of those, 25 have population-based restrictions, 8 have distance-based restrictions, 7 have quotas, and 6 require the licensing agency to consider density-related factors. Within the same group of 34 jurisdictions, 22 apply restrictions to both on- and off-premises outlets, 5 apply them only to on-premises outlets, and 7 apply them only to off-premises outlets. Among the 32 states where localities lack authority to license alcohol outlets, two-thirds have state-level laws restricting outlet density. State-level density restrictions also exist in approximately two-thirds of the states where localities have licensing authority. Case studies of Michigan and Massachusetts highlight how state-level density restrictions operate in practice., Conclusions: Two-thirds of jurisdictions have state-level alcohol outlet density restrictions, with population-based restrictions being the most common. In addition, outlet density restrictions may exist regardless of limits on local control and whether localities with authority to enact density restrictions have done so. Policymakers and others can reference this assessment to identify examples and opportunities to strengthen the alcohol policy environment in any given state., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Prostate-specific membrane antigen (PSMA) is present in high amounts in salivary glands, but it is unclear whether labeled binders of PSMA are excreted in the saliva., Methods: Ten patients with prostate cancer underwent whole-body [ 18 F]DCFPyL PET/CT (NCT03181867), and saliva samples were collected between 0-120 minutes post-injection. [ 18 F]DCFPyL salivary excretion was measured over 120 minutes and expressed as %ID/g. Protein-associated binding was estimated by the percentage of [ 18 F]DCFPyL versus parent radiotracer., Results: All PET scans of 10 patients (69 ± 8 years) with histologically confirmed prostate cancer (PSA= 2.4 ± 2.4, and Gleason Grade = 6-9) showed high uptake of [ 18 F]-DCFPyL in salivary glands while 8 patients demonstrated high uptake in the saliva at 45 minutes. The intact [ 18 F]-DCFPyL (98%) was also confirmed in the saliva samples at 120 min with increasing salivary radioactivity between 30-120 min., Conclusion: Systemically injected [ 18 F]DCFPyL shows salivary gland uptake, an increasing amount of which is secreted in saliva over time and is not maximized by 120 minutes post-injection. Although probably insignificant for diagnostic studies, patients undergoing PSMA-targeted therapies should be aware of radioactivity in saliva., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Fernandes, Roy, Basuli, Warner, Lindenberg, Mena, Adler, Griffiths, Choyke and Lin.)

Neuroendocrine tumors (NETs) express somatostatin receptors (SSTRs) 2 and 5. Modified variants of somatostatin, the cognate ligand for SSTR2 and SSTR5, are used in treatment for metastatic and locoregional disease. Peptide receptor radionuclide therapy with 177 Lu-DOTATATE (DOTA-octreotate), a β-particle-emitting somatostatin derivative, has demonstrated survival benefit in patients with SSTR-positive NETs. Despite excellent results, a subset of patients has tumors that are resistant to treatment, and alternative agents are needed. Targeted α-particle therapy has been shown to kill tumors that are resistant to targeted β-particle therapy, suggesting that targeted α-particle therapy may offer a promising treatment option for patients with 177 Lu-DOTATATE-resistant disease. Although DOTATATE can chelate the clinically relevant α-particle-emitting radionuclide 225 Ac, the labeling reaction requires high temperatures, and the resulting radioconjugate has suboptimal stability. Methods: We designed and synthesized MACROPATATE (MACROPA-octreotate), a novel radioconjugate capable of chelating 225 Ac at room temperature, and assessed its in vitro and in vivo performance. Results: MACROPATATE demonstrated comparable affinity to DOTATATE (dissociation constant, 21 nM) in U2-OS-SSTR2, a SSTR2-positive transfected cell line. 225 Ac-MACROPATATE demonstrated superior serum stability at 37°C over time compared with 225 Ac-DOTATATE. Biodistribution studies demonstrated higher tumor uptake of 225 Ac-MACROPATATE than of 225 Ac-DOTATATE in mice engrafted with subcutaneous H69 NETs. Therapy studies showed that 225 Ac-MACROPATATE exhibits significant antitumor and survival benefit compared with saline control in mice engrafted with SSTR-positive tumors. However, the increased accumulation of 225 Ac-MACROPATATE in liver and kidneys and subsequent toxicity to these organs decreased its therapeutic index compared with 225 Ac-DOTATATE. Conclusion: 225 Ac-MACROPATATE and 225 Ac-DOTATATE exhibit favorable therapeutic efficacy in animal models. Because of elevated liver and kidney accumulation and lower administered activity for dose-limiting toxicity of 225 Ac-MACROPATATE, 225 Ac-DOTATATE was deemed the superior agent for targeted α-particle peptide receptor radionuclide therapy., (© 2023 by the Society of Nuclear Medicine and Molecular Imaging.)

Labeling immune cells with zirconium-89 ( 89 Zr)-oxine has become a viable method to track cells in vivo by PET in various pre-clinical animal models and in clinical applications. Currently, 89 Zr-oxine cell labeling is performed manually, which requires a highly trained specialist and is prone to human error. As the first phase in developing a fully automated radiolabeling system to address this problem, we assess the use of acoustophoresis cell washing to replace the centrifugal cell washing used in the current 89 Zr-oxine cell radiolabeling procedure. To accomplish this, a cell radiolabeling procedure was developed in which two steps requiring a centrifuge to wash cells were replaced using acoustophoresis cell washing methods. The process was tested using murine EL4 lymphoma and T cells. The centrifuge cell labeling procedure was used as a control to compare the acoustophoresis cell washing procedure. The acoustophoresis method produced radiolabeled cells with similar properties to the centrifugal method when comparing labeling efficiency, labeled specific activity, efficacy of removing unbound 89 Zr-oxine from the suspension, cell viability measured using annexin V/propidium iodide staining and activation function. This suggests that acoustophoresis cell washing can be used in the design of an automated benchtop, good manufacture practice-qualified acoustophoresis cell radiolabeling device., (© 2022. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

The classical intent of PET imaging is to obtain the most accurate estimate of the amount of positron-emitting radiotracer in the smallest possible volume element located anywhere in the imaging subject at any time using the least amount of radioactivity. Reaching this goal, however, is confounded by an enormous array of interlinked technical issues that limit imaging system performance. As a result, advances in PET, human or animal, are the result of cumulative innovations across each of the component elements of PET, from data acquisition to image analysis. In the report that follows, we trace several of these advances across the imaging process with a focus on small animal PET., Competing Interests: Declaration of interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Published by Elsevier Inc.)

Purpose: Trials of adoptive natural killer (NK)-cell immunotherapy for hematologic malignancies have thus far shown only marginal effects, despite the potent in vitro antitumor activity of these cells. Homing of infused cells to tumor microenvironments is critical for efficacy, but has not been well characterized. We established a novel method to track and quantify the distribution of adoptively transferred NK cells using rhesus macaques (RM) as a clinically relevant preclinical model., Experimental Design: RM NK cells were expanded ex vivo for 14-21 days, labeled with 89 Zr-oxine complex, and assessed for phenotype, function, and survival. Trafficking of 89 Zr-labeled ex vivo -expanded NK cells infused into RMs was monitored and quantitated by serial positron emission tomography (PET)/CT ( n = 3, 2.05 ± 0.72 MBq, 23.5 ± 2.0 × 10 6 NK cells/kg) and compared with that of 89 Zr-labeled nonexpanded NK cells, apoptotic NK cells, and hematopoietic stem and progenitor cells (HSPC)., Results: NK cells retained sufficient levels of 89 Zr for accurate in vivo tracking for 7 days. 89 Zr labeling did not alter cellular phenotype, viability, or function. PET/CT showed NK cells initially localized in the lungs, followed by their migration to the liver, spleen, and, at low levels, bone marrow. One day following transfer, only 3.4% of infused NK cells localized to the BM versus 22.1% of HSPCs. No clinical side effects were observed, and dosimetry analysis indicated low organ radioexposures of 6.24 mSv/MBq (spleen) or lower., Conclusions: These data support translation of this technique to humans to track the distribution of adoptively infused cells and to develop novel techniques to improve immune cell homing to tumor microenvironments., (©2020 American Association for Cancer Research.)

Molecular imaging approaches for metabolic and physiologic imaging of tumors have become important for treatment planning and response monitoring. However, the relationship between the physiologic and metabolic aspects of tumors is not fully understood. Here, we developed new hyperpolarized MRI and electron paramagnetic resonance imaging procedures that allow more direct assessment of tumor glycolysis and oxygenation status quantitatively. We investigated the spatial relationship between hypoxia, glucose uptake, and glycolysis in three human pancreatic ductal adenocarcinoma tumor xenografts with differing physiologic and metabolic characteristics. At the bulk tumor level, there was a strong positive correlation between 18 F-FDG-PET and lactate production, while pO 2 was inversely related to lactate production and 18 F-2-fluoro-2-deoxy-D-glucose ( 18 F-FDG) uptake. However, metabolism was not uniform throughout the tumors, and the whole tumor results masked different localizations that became apparent while imaging. 18 F-FDG uptake negatively correlated with pO 2 in the center of the tumor and positively correlated with pO 2 on the periphery. In contrast to pO 2 and 18 F-FDG uptake, lactate dehydrogenase activity was distributed relatively evenly throughout the tumor. The heterogeneity revealed by each measure suggests a multimodal molecular imaging approach can improve tumor characterization, potentially leading to better prognostics in cancer treatment. SIGNIFICANCE: Novel multimodal molecular imaging techniques reveal the potential of three interrelated imaging biomarkers to profile the tumor microenvironment and interrelationships of hypoxia, glucose uptake, and glycolysis., (©2020 American Association for Cancer Research.)

Objective: 18 F-albumin, a vascular imaging agent, may have potential to assess tumor responses to anti-angiogenic therapies. In these studies tumor distribution volume of 18 F-albumin were first determined in various human tumor xenografts from biodistribtuion measurments and then one of the tumor type was used to evaluate changes in 18 F-albumin uptake in anti-angiognic tumor model. Method: 18 F-albumin was synthesized via conjugation of 6-[ 18 F]fluoronicotinic acid-2,3,5,6-tetrafluorophenyl ester, [ 18 F]F-Py-TFP, with rat albumin. From the biodistribution of 18 F-albumin in various human tumor xenografts tumor distribution volumes (DVs; tumor %ID/g :blood %ID/g ) were first determined at various time points. Then, the ability of 18 F-albumin to detect tumor angiogenic inhibition in one of these tumor types (U87MG) following treatment with sunitinib was evaluated by position emission tomography (PET) imaging at 0, 7, 14, and 21 days post treatment. Caliper measurements of tumor dimensions were also made at these same times. At Day 21, following imaging, biodistributions, autoradiography of tumor tissues and tumor blood vessel counts (CD31 IHC) were performed. Results: 18 F-albumin retention in various tumors steadily increased over time with U87MG tumor exhibiting the highest uptake (DV) at all times. Significant decreases in 18 F-albumin DVs were observed one week post-treatement (-39%) vs. controls whereas tumor caliper volumes were not significantly decreased until days 14 and 21. At day 21 the significant decrease in DVs in the treatment group (-44%) paralleled biodistribution DV measurements and was consistent with autoradiography and CD31 IHC findings. Conclusion: These data suggest that 18 F-albumin DVs obtained by imaging may serve as an early biomarker of the effectiveness of anti-angiogenic therapy and thus aid in patient management and treatment planning.

Background: Bone fracture healing is dependent upon the rapid migration and engraftment of bone marrow (BM) progenitor and stem cells to the site of injury. Stromal cell-derived factor-1 plays a crucial role in recruiting BM cells expressing its receptor CXCR4. Recently, a CXCR4 antagonist, plerixafor, has been used to mobilize BM cells into the blood in efforts to enhance cell migration to sites of injury presumably improving healing. In this study, we employed zirconium-89 ( 89 Zr)-oxine-labeled BM cells imaged with positron emission tomography (PET)/computed tomography (CT) to visualize and quantitate BM cell trafficking following acute bone injury and to investigate the effect of plerixafor on BM cell homing. Unilateral 1-mm incisions were created in the distal tibia of mice either on the same day (d0) or 24 h (d1) after 89 Zr-oxine-labeled BM cell transfer (n = 4-6, 2-2.3 × 10 7 cells at 9.65-15.7 kBq/10 6 cells). Serial microPET/CT imaging was performed and migration of 89 Zr-labeled cells to the bone injury was quantified. The effects of three daily doses of plerixafor on cell trafficking were evaluated beginning on the day of fracture generation (n = 4-6). The labeled cells localizing to the fracture were analyzed by flow cytometry and immunohistochemistry., Results: In d0- and d1-fracture groups, 0.7% and 1.7% of administered BM cells accumulated within the fracture, respectively. Plerixafor treatment reduced BM cell migration to the fracture by approximately one-third (p < 0.05 for both fracture groups). Flow cytometry analysis of donor cells collected from the injured site revealed a predominance of CD45 + stem/progenitor cell populations and subsequent histological analysis demonstrated the presence of donor cells engrafted within sites of fracture repair., Conclusion: 89 Zr-oxine labeling enabled visualization and quantitation of BM cell recruitment to acute fractures and further demonstrated that plerixafor plays an inhibitory role in this recruitment.

Objective: Building on the extensive research literature demonstrating that increasing alcohol prices reduces excessive alcohol consumption and related harms, this article presents the results of a 50-state review of local authority to tax alcohol in the United States., Method: Between 2013 and 2015, legal databases and government websites were reviewed to collect and analyze relevant statutes, ordinances, and case law. Results reflect laws in effect as of January 1, 2015., Results: Nineteen states allow local alcohol taxation, although 15 of those have one or more major restrictions on local authority to tax. The types of major restrictions are (a) restrictions on the type of beverage and alcohol content that can be taxed, (b) caps on local alcohol taxes, (c) restrictions on the type of retailer where taxes can be imposed, (d) restrictions on jurisdictions within the state that can levy taxes, and (e) requirements for how tax revenue can be spent., Conclusions: The number and severity of restrictions on local authority to tax alcohol vary across states. Previous research has shown that increases in alcohol taxes can lead to reduced excessive alcohol consumption, which provides public health and economic benefits. Taxes can also provide funds to support local prevention and treatment services. Local alcohol taxes therefore present an important policy opportunity, both in states that restrict local authority and in states where local authority exists but is underused.