Comparative Study of Dimeric Fibroblast Activation Protein-Targeting Radioligands Labeled with Fluorine-18, Copper-64, and Gallium-68.

Fibroblast activation protein inhibitors (FAPIs) labeled with gallium-68 and lutetium-177 show potential for use in the diagnosis and treatment of various cancers expressing FAP. However, Lu-labeled FAPIs often exhibit short tumor retention time, limiting their therapeutic applications. To improve tumor retention, we synthesized three radiolabeled dimeric FAPIs, [F], [Cu], and [Ga].

Evaluation of Dynamic Light Scattering as an Effective Quality Control Method for Aggregates in Radiolabeled Antibodies.

Radiolabeled antibodies are promising for targeted cancer imaging, but their structural integrity may suffer during bioconjugation and radiolabeling, leading to undetected aggregation. This study evaluates dynamic light scattering (DLS) as a complementary method to size-exclusion high-performance liquid chromatography (SEC-HPLC) for detecting aggregation in radiolabeled antibodies. Trastuzumab was conjugated with a NOTA bifunctional chelator at various ratios, radiolabeled with [Cu]CuCl, and analyzed by using DLS and SEC-HPLC before and after purification.

Evaluating 64Cu-DOTA-rituximab as a PET agent in patients with B-cell lymphoma: a head-to-head comparison with 18F-fluorodeoxyglucose PET/computed tomography.

Background: This study aimed to evaluate the biodistribution of 64Cu-DOTA-rituximab and its diagnostic feasibility for lymphoma using CD20-targeted 64Cu-DOTA-rituximab PET/computed tomography (PET/CT).

Methods: A prospective study involving six patients diagnosed with lymphoma was conducted between January 2022 and January 2023. These patients underwent 18F-fluorodeoxyglucose (18F-FDG) and 64Cu-DOTA-rituximab PET/CT scans.

Efficient Radiolabeling of Proteins and Antibodies via Maleamate-Cysteine Bioconjugation.

The study introduces a novel maleamate-based prosthetic group specifically designed for efficient, site-specific radioiodination of biomolecules that contain or are modified with cysteine residues. This strategy is a compelling alternative to the conventional maleimide-based approach, demonstrating outstanding attributes such as high radiochemical yield, rapid reaction kinetics, applicability in aqueous media at neutral pH, and exceptional stability under a competitive environment.

From molecules to medicine: thiol selective bioconjugation in synthesis of diagnostic and therapeutic radiopharmaceuticals.

Radiolabeling of biomolecules and cells with radiolabeled prosthetic groups has significant implications for nuclear medicine, imaging, and radiotherapy. Achieving site-specific and controlled incorporation of radiolabeled prostheses under mild reaction conditions is crucial for minimizing the impact on the bioactivity of the radiolabeled compounds. The targeting of natural and abundant amino acids during radiolabeling of biomolecules often results in nonspecific and uncontrolled modifications.

Feasibility Study of Single-Photon Emission Computed Tomography with Iodine-123 Labeled Metaiodobenzylguanidine for Preclinical Evaluation of Labetalol as a β-Adrenergic Receptor Blocker.

Among clinically used radiopharmaceuticals, iodine-123 labeled metaiodobenzylguanidine ([I]mIBG) serves for diagnosing neuroendocrine tumors and obtaining images of myocardial sympathetic innervation. mIBG, a structural analogue of norepinephrine (NE), a neurotransmitter acting in peripheral and central nerves, follows a pathway similar to NE, transmitting signals through the NE transporter (NET) located at synaptic terminals. It moves through the body without decomposing, enabling noninvasive image evaluation.

Cu-Labeled Boron-Containing Cyclic RGD Peptides for BNCT and PET Imaging.

The burgeoning interest in developing boron neutron capture therapy (BNCT) tracers and their accompanying diagnostics for the treatment of recalcitrant tumors has prompted this investigation. Our study aims to devise a tumor treatment strategy utilizing BNCT to target the αβ integrin. To this end, we propose a pioneering boron-infused cyclic Arg-Gly-Asp (RGD) peptide, cRGD(d-BPA)K, designed as an efficacious BNCT tracer.

Effect of developmental stress on the neuronal circuits related to excitation-inhibition balance and mood in adulthood.

Introduction: Traumatic events in early life have a deleterious effect on the development of normal brain developments, which may be a cause of various psychiatric disorders in adulthood. Most prior studies focused on molecular biological aspects, and research on functional changes in neural circuits is still limited. We aimed to elucidate the effect of early life stress on excitation-inhibition and serotonergic neurotransmission in the adulthood using non-invasive functional molecular imaging (positron emission tomography, PET).

Evaluation of PSMA target diagnostic PET tracers for therapeutic monitoring of [Lu]ludotadipep of prostate cancer: Screening of PSMA target efficiency and biodistribution using [F]DCFPyL and [Ga]PSMA-11.

We have compared the similarity of the in vivo distribution of the prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging agents [F]DCFPyL, [Ga]galdotadipep, and [Ga]PSMA-11. This study is designed for a further selection of a PSMA-targeted PET imaging agent for the therapeutic evaluation of [Lu]ludotadipep, our previously developed prostate-specific membrane antigen (PSMA)-targeted prostate cancer therapeutic radiopharmaceutical. In vitro cell uptake was performed to evaluate the affinity to PSMA using PSMA + PC3-PIP, and PSMA- PC3-flu was used for the study.

Early Prediction of Radiation-Induced Pulmonary Fibrosis Using Gastrin-Releasing Peptide Receptor-Targeted PET Imaging.

Early diagnosis of radiation-induced pulmonary fibrosis (RIPF) in lung cancer patients after radiation therapy is important. A gastrin-releasing peptide receptor (GRPR) mediates the inflammation and fibrosis after irradiation in mice lungs. Previously, our group synthesized a GRPR-targeted positron emission tomography (PET) imaging probe, [Cu]Cu-NODAGA-galacto-bombesin (BBN), an analogue peptide of GRP.

Optimizing and determining the click chemistry mediated Cu-64 radiolabeling and physiochemical characteristics of trastuzumab conjugates.

Over the last decade, Cu-labeling of monoclonal antibody (mAb) via inverse electron demand Diels-Alder click chemistry (IEDDA) have received much attention. Despite the tetrazine-transcyclooctene (Tz-TCO) click chemistry's convenience and efficiency in mAb labeling, there is limited information about the ideal parameters in the development of click chemistry mediated (radio)immunoconjugates. This encourages us to conduct a systematic optimization while concurrently determining the physiochemical characteristics of the model mAb, trastuzumab, and TCO conjugates.

64 Cu-DOTA-Rituximab PET/CT of B-Cell Non-Hodgkin Lymphoma for Imaging the CD20 Expression.

64 Cu-DOTA-rituximab PET/CT was performed on a 62-year-old and a 71-year-old men diagnosed with B-cell non-Hodgkin lymphoma. Compared with 18 F-FDG PET/CT, lesions could be detected more sensitively, and it was confirmed that there was no discernible 64 Cu-DOTA-rituximab uptake in the tumor other than lymphoma. 64 Cu-DOTA-rituximab PET/CT could be a powerful tool for the diagnosis and monitoring treatment response of lymphoma because of imaging the CD20 expression.

Preclinical Evaluation of hnRNPA2B1 Antibody in Human Triple-Negative Breast Cancer MDA-MB-231 Cells via PET Imaging.

Triple-negative breast cancer (TNBC) does not express estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Because TNBC lacks the expression of commonly targeted receptors, it is challenging to develop a new imaging agent for this cancer subtype. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are RNA-protein complexes that have been linked to tumor development and progression.

Amyloid pathology induces dysfunction of systemic neurotransmission in aged APPswe/PS2 mice.

This study aimed to investigate how amyloid pathology affects the functional aspects of neurotransmitter systems in Alzheimer's disease. APPswe/PS2 mice (21 months of age) and wild-type (WT) mice underwent positron emission tomography (PET) and magnetic resonance spectroscopy (MRS). First, we obtained F-FDG and F-florbetaben PET scans to evaluate neuronal integrity and amyloid pathology.

In vivo detection of hydrogen sulfide in the brain of live mouse: application in neuroinflammation models.

Purpose: Hydrogen sulfide (HS) plays important roles in brain pathophysiology. However, nuclear imaging probes for the in vivo detection of brain HS in living animals have not been developed. Here, we report the first nuclear imaging probe that enables in vivo imaging of endogenous HS in the brain of live mice.

KSNM60: The History of Radiopharmaceutical Sciences in Korea.

A number of researchers in Korea have tried to set-up the production of radionuclides and develop new radiopharmaceuticals for several decades. Thanks to their 60-year endeavor to advance the field of radiopharmaceutical sciences, now we have a lot of research units and facilities in Korea. Still, there are huge number of issues to be solved in radiopharmaceutical sciences; however, our efforts will be continued to develop new radiopharmaceuticals and to apply the new radiopharmaceuticals into nuclear medicine field.

Feasibility of Gd-Based prostate cancer targeted magnetic resonance agents using prostate specific membrane antigen.

The aim of this work was to evaluate Gd-FC705, a prostate-specific membrane antigen (PSMA)-targeted MRI contrast agent. The r and r relaxivities of Gd-FC705 are 5.94 mMs and 17.

Developmental complex trauma induces the dysfunction of the amygdala-mPFC circuit in the serotonergic and dopaminergic systems.

Developmental complex trauma is strongly associated with various psychiatric disorders in adulthood. Multiple lines of evidence have demonstrated that the amygdala-mPFC circuit regulates emotion and plays an important role in stress reactions. However, most studies on developmental trauma have mainly focused on neurological aspects in biological, behavioral, and structural changes with regard to a single stressor.

Optimal design of high-voltage DC power supply of 1.2 MV/45 mA applied to boron neutron capture therapy system.

To build a proton beam accelerator that can be applied to a boron neutron capture therapy system based on an electrostatic accelerator, a high-voltage direct-current (DC) power supply system equivalent to the generation of neutrons should be provided. The symmetrical Cockcroft-Walton voltage multiplier method is suitable for stable acceleration of the proton beam in the tandem electrostatic accelerator in this system. Before the second step-up with the Cockcroft-Walton circuit, the design of the inverter is prioritized by preponderantly considering the first voltage and resonance frequency.

Decreased in vivo glutamate/GABA ratio correlates with the social behavior deficit in a mouse model of autism spectrum disorder.

To diagnose autism spectrum disorder (ASD), researchers have sought biomarkers whose alterations correlate with the susceptibility to ASD. However, biomarkers closely related to the pathophysiology of ASD are lacking. Even though excitation/inhibition (E/I) imbalance has been suggested as an underlying mechanism of ASD, few studies have investigated the actual ratio of glutamate (Glu) to γ-aminobutyric acid (GABA) concentration in vivo.