Switching the Chemoselectivity in the Preparation of [F]FNA--CooP, a Free Thiol-Containing Peptide for Targeted Positron Emission Tomography Imaging of Fatty Acid Binding Protein 3.

Fatty acid binding protein 3 (FABP3) is expressed both in tumor cells and in the tumor vasculature, making it a potential target for medical imaging and therapy. In this study, we aimed to radiolabel a CooP peptide with a free amino and thiol group, and evaluate the radiolabeled product [F]FNA--CooP for imaging FABP3 expression in breast cancer brain metastases by positron emission tomography. [F]FNA--CooP was prepared by highly chemoselective -acylation and characterized using different chemical approaches.

Analysis of sleep apnea research with a special focus on the use of positron emission tomography as a study tool.

The quality of sleep plays a significant role in determining human well-being, and studying sleep and sleep disorders using various methods can aid in the prevention and treatment of diseases. Positron emission tomography (PET) is a noninvasive and highly sensitive medical imaging technique that has been widely adopted in the clinic. This review article provides data on research activity related to sleep and sleep apnea and discusses the use of PET in investigating sleep apnea and other sleep disorders.

Mannose receptor independent uptake of transmembrane glycocluster immunostimulant TADM by macrophages.

Triacedimannose (TADM) is a synthetic trivalent acetylated glycocluster comprising β-1,2-linked mannobioses that in humans induces TNF in vitro and in vivo. The purpose of this study was to analyze whether uptake of acetylated glycoclusters of such β-1,2-linked mannobioses by human macrophages is dependent on the mannose receptor (CD206) or if it is mediated by transmembrane activation. In mannose receptor blocking assays, monocyte-derived polarized macrophages were incubated with carbohydrate test-compounds and their binding to the mannose receptor was demonstrated as inhibition of FITC-Dextran binding.

Macrophage mannose receptor CD206 targeting of fluoride-18 labeled mannosylated dextran: A validation study in mice.

Purpose: Aluminum fluoride-18-labeled 1,4,7-triazacyclononane-1,4,7-triacetic acid-conjugated mannosylated dextran derivative (Al[F]F-NOTA-D10CM) is a new tracer for PET imaging. We report here on in vitro and in vivo validation of the tracer's ability to target the macrophage mannose receptor CD206.

Methods: First, the uptake of intravenously (i.

Radiosynthesis, structural identification and in vitro tissue binding study of [F]FNA-S-ACooP, a novel radiopeptide for targeted PET imaging of fatty acid binding protein 3.

Background: Fatty acid binding protein 3 (FABP3) is a target with clinical relevance and the peptide ligand ACooP has been identified for FABP3 targeting. ACooP is a linear decapeptide containing a free amino and thiol group, which provides opportunities for conjugation. This work is to develop methods for radiolabeling of ACooP with fluorine-18 (F) for positron emission tomography (PET) applications, and evaluate the binding of the radiolabeled ACooP in human tumor tissue sections with high FABP3 expression.

Tetrazine Glycoconjugate for Pretargeted Positron Emission Tomography Imaging of -Cyclooctene-Functionalized Molecular Spherical Nucleic Acids.

Pretargeted concept in positron emission tomography (PET) together with bioorthogonal chemistry is an elegant solution to study processes with slow pharmacokinetics by utilizing radiotracers labeled with short-lived radionuclides. Namely, radiotracers based on tetrazine ligation with -cyclooctene (TCO) via the inverse electron demand Diels-Alder (IEDDA) reaction have become a state-of-the-art for the pretargeted PET imaging. For radiolabeling of tetrazine scaffolds, indirect radiofluorination methods are often preferred, as tetrazines are vulnerable to harsh conditions typically necessary for the direct radiofluorination.

Imaging of Myocardial αβ Integrin Expression for Evaluation of Myocardial Injury After Acute Myocardial Infarction.

[Ga]Ga-NODAGA-Arg-Gly-Asp (RGD) is a PET tracer targeting αβ integrin, which is upregulated during angiogenesis soon after acute myocardial infarction (AMI). We prospectively evaluated determinants of myocardial uptake of [Ga]Ga-NODAGA-RGD and its associations with left ventricular (LV) function in patients after AMI. Myocardial blood flow and [Ga]Ga-NODAGA-RGD uptake (60 min after injection) were evaluated by PET in 31 patients 7.

Vascular adhesion protein-1-targeted PET imaging in autoimmune myocarditis.

Background: Vascular adhesion protein-1 (VAP-1) is an adhesion molecule and primary amine oxidase, and Gallium-68-labeled 1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetra-acetic acid conjugated sialic acid-binding immunoglobulin-like lectin 9 motif containing peptide ([Ga]Ga-DOTA-Siglec-9) is a positron emission tomography (PET) tracer targeting VAP-1. We evaluated the feasibility of PET imaging with [Ga]Ga-DOTA-Siglec-9 for the detection of myocardial lesions in rats with autoimmune myocarditis.

Methods: Rats (n = 9) were immunized twice with porcine cardiac myosin in complete Freund's adjuvant.

Atomic Local Ordering and Alloying Effects on the Mg(SbBi) Thermoelectric Material.

Mg(SbBi) alloy has been extensively studied in the last 5 years due to its exceptional thermoelectric (TE) performance. The absence of accurate force field for inorganic alloy compounds presents great challenges for computational studies. Here, we explore the atomic microstructure, thermal, and elastic properties of the Mg(SbBi) alloy at different solution concentrations through atomic simulations with a highly accurate machine learning interatomic potential (ML-IAP).

Aluminum Fluoride-18 Labeled Mannosylated Dextran: Radiosynthesis and Initial Preclinical Positron Emission Tomography Studies.

Purpose: In addition to being expressed on liver sinusoidal endothelial cells, mannose receptors are also found on antigen-presenting cells, including macrophages, which are mainly involved in the inflammation process. Dextran derivatives of various sizes containing cysteine and mannose moieties have previously been labeled with Tc and used for single-photon emission computed tomography imaging of sentinel lymph nodes. In this study, we radiolabeled 21.

Preclinical Evaluation of Zr-Desferrioxamine-Bexmarilimab, a Humanized Antibody Against Common Lymphatic Endothelial and Vascular Endothelial Receptor-1, in a Rabbit Model of Renal Fibrosis.

Bexmarilimab is a new humanized monoclonal antibody against common lymphatic endothelial and vascular endothelial receptor-1 (CLEVER-1) and is in clinical trials for macrophage-guided cancer immunotherapy. In addition being associated with cancer, CLEVER-1 is also associated with fibrosis. To facilitate prospective human PET studies, we preclinically evaluated Zr-labeled bexmarilimab in rabbits.

[Ga]Ga-DOTA-Siglec-9 Detects Pharmacodynamic Changes of FAP-Targeted IL2 Variant Immunotherapy in B16-FAP Melanoma Mice.

Vascular adhesion protein-1 (VAP-1) is an inflammation-inducible adhesion molecule, which supports contact between leukocytes and inflamed endothelium. There is evidence that VAP-1 is involved in the recruitment of leukocytes to melanoma tumors. Interleukin-2 (IL-2)-based immunotherapy is an efficient therapy that promotes immune system activity against cancers but is associated with toxicity.

Corrigendum: Exploiting Glutamine Consumption in Atherosclerotic Lesions by Positron Emission Tomography Tracer (2,4)-4-F-Fluoroglutamine.

[This corrects the article DOI: 10.3389/fimmu.2022.

Ga-Citrate PET of Healthy Men: Whole-Body Biodistribution Kinetics and Radiation Dose Estimates.

Ga-citrate has one of the simplest chemical structures of all Ga-radiopharmaceuticals, and its clinical use is justified by the proven medical applications using its isotope-labeled compound Ga-citrate. To support broader application of Ga-citrate in medical diagnosis, further research is needed to gain clinical data from healthy volunteers. In this work, we studied the biodistribution of Ga-citrate and subsequent radiation exposure from it in healthy men.

Exploiting Glutamine Consumption in Atherosclerotic Lesions by Positron Emission Tomography Tracer (2,4)-4-F-Fluoroglutamine.

Increased glutamine metabolism by macrophages is associated with development of atherosclerotic lesions. Positron emission tomography/computed tomography (PET/CT) with a glutamine analog (2S,4)-4-F-fluoroglutamine (F-FGln) allows quantification of glutamine consumption . Here, we investigated uptake of F-FGln by atherosclerotic lesions in mice and compared the results with those obtained using the glucose analog 2-deoxy-2-F-fluoro--glucose (F-FDG).

Evaluation of [Ga]Ga-NODAGA-RGD for PET Imaging of Rat Autoimmune Myocarditis.

The Gallium-labeled 1,4,7-triazacyclononane-1-glutaric acid-4,7-diacetic acid conjugated radiolabelled arginine-glycine-aspartic acid peptide ([Ga]Ga-NODAGA-RGD) is a positron emission tomography (PET) tracer binding to cell surface receptor αβ integrin that is upregulated during angiogenesis and inflammation. We studied whether αβ targeting PET imaging can detect myocardial inflammation in a rat model of autoimmune myocarditis. To induce myocarditis, rats ( = 8) were immunized with porcine cardiac myosin in complete Freund's adjuvant on days 0 and 7.

Comparison of: (2,4)-4-[F]Fluoroglutamine, [C]Methionine, and 2-Deoxy-2-[F]Fluoro--Glucose and Two Small-Animal PET/CT Systems Imaging Rat Gliomas.

Purpose: The three positron emission tomography (PET) imaging compounds: (2,4)-4-[F]Fluoroglutamine ([F]FGln), -[methyl-C]Methionine ([C]Met), and 2-deoxy-2-[F]fluoro--glucose ([F]FDG) were investigated to contrast their ability to image orthotopic BT4C gliomas in BDIX rats. Two separate small animal imaging systems were compared for their tumor detection potential. Dynamic acquisition of [F]FGln was evaluated with multiple pharmacokinetic models for future quantitative comparison.

Graph network based deep learning of bandgaps.

Recent machine learning models for bandgap prediction that explicitly encode the structure information to the model feature set significantly improve the model accuracy compared to both traditional machine learning and non-graph-based deep learning methods. The ongoing rapid growth of open-access bandgap databases can benefit such model construction not only by expanding their domain of applicability but also by requiring constant updating of the model. Here, we build a new state-of-the-art multi-fidelity graph network model for bandgap prediction of crystalline compounds from a large bandgap database of experimental and density functional theory (DFT) computed bandgaps with over 806 600 entries (1500 experimental, 775 700 low-fidelity DFT, and 29 400 high-fidelity DFT).

Atomistic simulations of dislocation mobility in refractory high-entropy alloys and the effect of chemical short-range order.

Refractory high-entropy alloys (RHEAs) are designed for high elevated-temperature strength, with both edge and screw dislocations playing an important role for plastic deformation. However, they can also display a significant energetic driving force for chemical short-range ordering (SRO). Here, we investigate mechanisms underlying the mobilities of screw and edge dislocations in the body-centered cubic MoNbTaW RHEA over a wide temperature range using extensive molecular dynamics simulations based on a highly-accurate machine-learning interatomic potential.

Association between [Ga]NODAGA-RGDyK uptake and dynamics of angiogenesis in a human cell-based 3D model.

Radiolabeled RGD peptides targeting expression of αβ integrin have been applied to in vivo imaging of angiogenesis. However, there is a need for more information on the quantitative relationships between RGD peptide uptake and the dynamics of angiogenesis. In this study, we sought to measure the binding of [Ga]NODAGA-RGDyK to αβ integrin in a human cell-based three-dimensional (3D) in vitro model of angiogenesis, and to compare the level of binding with the amount of angiogenesis.

Evaluation of glucagon-like peptide-1 receptor expression in nondiabetic and diabetic atherosclerotic mice using PET tracer Ga-NODAGA-exendin-4.

Cardiovascular effects of glucagon-like peptide-1 receptor (GLP-1R) agonist therapies are potentially mediated by anti-inflammatory effects on atherosclerosis. Our study demonstrates that Ga-NODAGA-exendin-4, a radioligand specifically targeting GLP-1R, detects GLP-1R expression in inflamed atherosclerotic lesions in nondiabetic and diabetic hypercholesterolemic mice. Immunofluorescence staining suggests that GLP-1R is primarily localized in M2 macrophages in lesions.