scholarly journals F-18 Labeled Vasoactive Intestinal Peptide Analogue in the PET Imaging of Colon Carcinoma in Nude Mice

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Dengfeng Cheng ◽  
Yuxia Liu ◽  
Hua Shen ◽  
Lifang Pang ◽  
Duanzhi Yin ◽  
...  
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Colon Carcinoma ◽  
Pet Imaging ◽  
Specific Activity ◽  
Imaging Study ◽  
Radiochemical Yield ◽  
Receptor Imaging ◽  
Improved Stability ◽  
Vip Receptor

As large amount of vasoactive intestinal peptide (VIP) receptors are expressed in various tumors and VIP-related diseases, radiolabeled VIP provides a potential PET imaging agent for VIP receptor. However, structural modification of VIP is required before being radiolabeled and used for VIP receptor imaging due to its poor in vivo stability. As a VIP analogue, [R8, 15, 21, L17]-VIP exhibited improved stability and receptor specificity in preliminary studies. In this study, F-18 labeled [R8,15,21, L17]-VIP was produced with the radiochemical yield being as high as33.6%±3%(decay-for-corrected,n=5) achieved within 100 min, a specific activity of 255 GBq/μmol, and a radiochemical purity as high as 99% as characterized by radioactive HPLC, TLC, and SDS-Page radioautography. A biodistribution study in normal mice also demonstrated fast elimination of F-18 labeled [R8,15,21, L17]-VIP in the blood, liver, and gastrointestinal tracts. A further micro-PET imaging study in C26 colon carcinoma bearing mice confirmed the high tumor specificity, with the tumor/muscle radioactivity uptake ratio being as high as 3.03 at 60 min following injection, and no apparent radioactivity concentration in the intestinal tracts. In addition, blocking experiment and Western Blot test further confirmed its potential in PET imaging of VIP receptor-positive tumor.

scholarly journals Improved Detection of Molecular Markers of Atherosclerotic Plaques Using Sub-Millimeter PET Imaging

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1838 ◽  
Author(s):  
Jessica Bridoux ◽  
Sara Neyt ◽  
Pieterjan Debie ◽  
Benedicte Descamps ◽  
Nick Devoogdt ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Ex Vivo ◽  
High Sensitivity ◽  
Radiochemical Yield ◽  
Control Group ◽  
Complexing Agent ◽  
Atherosclerotic Plaques ◽  
Atherosclerotic Lesions ◽  
Pet Ct

Since atherosclerotic plaques are small and sparse, their non-invasive detection via PET imaging requires both highly specific radiotracers as well as imaging systems with high sensitivity and resolution. This study aimed to assess the targeting and biodistribution of a novel fluorine-18 anti-VCAM-1 Nanobody (Nb), and to investigate whether sub-millimetre resolution PET imaging could improve detectability of plaques in mice. The anti-VCAM-1 Nb functionalised with the novel restrained complexing agent (RESCA) chelator was labelled with [18F]AlF with a high radiochemical yield (>75%) and radiochemical purity (>99%). Subsequently, [18F]AlF(RESCA)-cAbVCAM1-5 was injected in ApoE−/− mice, or co-injected with excess of unlabelled Nb (control group). Mice were imaged sequentially using a cross-over design on two different commercially available PET/CT systems and finally sacrificed for ex vivo analysis. Both the PET/CT images and ex vivo data showed specific uptake of [18F]AlF(RESCA)-cAbVCAM1-5 in atherosclerotic lesions. Non-specific bone uptake was also noticeable, most probably due to in vivo defluorination. Image analysis yielded higher target-to-heart and target-to-brain ratios with the β-CUBE (MOLECUBES) PET scanner, demonstrating that preclinical detection of atherosclerotic lesions could be improved using the latest PET technology.

scholarly journals Synthesis and evaluation of novel F-18-labeled pyrimidine derivatives: potential FAK inhibitors and PET imaging agents for cancer detection

RSC Advances ◽  
2017 ◽  
Vol 7 (36) ◽  
pp. 22388-22399 ◽  
Author(s):  
Dawei Wang ◽  
Yu Fang ◽  
Hang Wang ◽  
Xingyu Xu ◽  
Jianping Liu ◽  
...  
Keyword(s):  
Cancer Detection ◽  
Pet Imaging ◽  
Imaging Study ◽  
Imaging Agents ◽  
Post Injection ◽  
Pyrimidine Derivatives ◽  
Micropet Imaging ◽  
Tumor Bearing ◽  
Biodistribution Data

Compound [18F]-8a exhibited good in vivo biodistribution data in mice bearing S180 tumor. And the microPET imaging study of [18F]-8a in S180 tumor-bearing mice was also preformed, which illustrated that the uptake in S180 tumor at 60 min post-injection of [18F]-8a was obvious.

scholarly journals Synthesis of a novel 89Zr labeled HER2 affibody and its application study in tumor PET imaging

2020 ◽  
Author(s):  
Yuping Xu ◽  
Lizhen Wang ◽  
Donghui Pan ◽  
Junjie Yan ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Radiochemical Purity ◽  
Ex Vivo ◽  
Radiochemical Yield ◽  
Immunohistochemical Analysis ◽  
In Vivo Studies ◽  
Potential Candidate ◽  
Synthesis Time ◽  
Normal Tissues

Abstract Background: Human epidermal growth factor receptor-2 (HER2) is an essential biomarker for tumor treatment. Affibody is an ideal vector for preparing HER2 specific probes because of high affinity and rapid clearance from normal tissues etc. Zirconium-89 is a PET imaging isotope with a long half-life and suitable for monitoring biological processes for more extended periods. In this study, a novel 89 Zr-labeled HER2 affibody, [ 89 Zr]Zr-DFO-MAL-Cys-MZHER2, was synthesized, and its imaging characters were also assessed. Results: The precursor, DFO-MAL-Cys-MZHER2, was obtained with a yield of nearly 50%. The radiochemical yield of [ 89 Zr]Zr -DFO-MAL-Cys-MZHER2 was 90.2±1.9% , and the radiochemical purity was higher than 95%. The total synthesis time was only 30 minutes. The probe was stable in PBS and serum. The tracer accumulated in HER2 overexpressing human ovarian cancer SKOV-3 cells. In vivo studies in mice bearing tumors showed that the probe highly retained in SKOV-3 xenografts even for 48 hours. The tumors were visualized with good contrast to normal tissues. ROI analysis revealed that the average uptake values in the tumor were greater than 5%IA/g during 48 hours postinjection. On the contrary, the counterparts of MCF-7 tumors kept low levels（~1%IA/g）. The outcome was consistent with the immunohistochemical analysis and ex vivo autoradiography. The probe quickly cleared from the normal organs except kidneys and mainly excreted through the urinary system. Conclusion: The novel HER2 affibody for PET imaging was easily prepared with satisfactory labeling yield and radiochemical purity. [ 89 Zr]Zr-DFO-MAL-Cys-MZHER2 is a potential candidate for detecting HER2 expression. It may play specific roles in clinical cancer theranostics.

scholarly journals Synthesis and Initial In Vivo Evaluation of [11C]AZ683 – a Novel PET Radiotracer for Colony Stimulating Factor 1 Receptor (CSF1R)

2018 ◽  
Author(s):  
Sean S. Tanzey ◽  
Xia Shao ◽  
Jenelle Stauff ◽  
Janna Arteaga ◽  
Phillip Sherman ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
High Specific Activity ◽  
Colony Stimulating Factor ◽  
Positron Emission ◽  
New Strategy ◽  
Activity Yield ◽  
Stimulating Factor

Positron emission tomography (PET) imaging of Colony Stimulating Factor 1 Receptor (CSF1R) is a new strategy for quantifying both neuroinflammation and inflammation in the periphery since CSF1R is expressed on microglia. AZ683 has high affinity for CSF1R (Ki = 8 nM; IC50 = 6 nM) and >250-fold selectivity over 95 other kinases and, in this paper, we report the radiosynthesis of [11C]AZ683 and initial evaluation of its use in CSF1R PET. [11C]AZ683 was synthesized by 11C-methylation of the desmethyl precursor with [11C]MeOTf in 3.0% non-corrected activity yield (based upon [11C]MeOTf), >99% radiochemical purity and high specific activity. Preliminary PET imaging with [11C]AZ683 revealed no brain uptake in rodents and nonhuman primates suggesting that [11C]AZ683 is a poor candidate for imaging neuroinflammation, but that it could still be useful for peripheral imaging of inflammation.

scholarly journals Synthesis of a novel 89Zr labeled HER2 affibody and its application study in tumor PET imaging

2020 ◽  
Author(s):  
Yuping Xu ◽  
Lizhen Wang ◽  
Donghui Pan ◽  
Junjie Yan ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Radiochemical Purity ◽  
Ex Vivo ◽  
Radiochemical Yield ◽  
Immunohistochemical Analysis ◽  
In Vivo Studies ◽  
Potential Candidate ◽  
Synthesis Time ◽  
Normal Tissues

Abstract Background: Human epidermal growth factor receptor-2 (HER2) is an essential biomarker for tumor treatment. Affibody is an ideal vector for preparing HER2 specific probes because of high affinity and rapid clearance from normal tissues etc. Zirconium-89 is a PET imaging isotope with a long half-life and suitable for monitoring biological processes for more extended periods. In this study, a novel 89Zr-labeled HER2 affibody, [89Zr]Zr-DFO-MAL-Cys-MZHER2, was synthesized, and its imaging characters were also assessed. Results: The precursor, DFO-MAL-Cys-MZHER2, was obtained with a yield of nearly 50%. The radiochemical yield of [89Zr]Zr -DFO-MAL-Cys-MZHER2 was 90.2±1.9% , and the radiochemical purity was higher than 95%. The total synthesis time was only 30 minutes. The probe was stable in PBS and serum. The tracer accumulated in HER2 overexpressing human ovarian cancer SKOV-3 cells. In vivo studies in mice bearing tumors showed that the probe highly retained in SKOV-3 xenografts even for 48 hours. The tumors were visualized with good contrast to normal tissues. ROI analysis revealed that the average uptake values in the tumor were greater than 5%IA/g during 48 hours postinjection. On the contrary, the counterparts of MCF-7 tumors kept low levels（~1%IA/g）. The outcome was consistent with the immunohistochemical analysis and ex vivo autoradiography. The probe quickly cleared from the normal organs except kidneys and mainly excreted through the urinary system. Conclusion: The novel HER2 affibody for PET imaging was easily prepared with satisfactory labeling yield and radiochemical purity. [89Zr]Zr-DFO-MAL-Cys-MZHER2 is a potential candidate for detecting HER2 expression. It may play specific roles in clinical cancer theranostics.

scholarly journals Radiolabeling and Quantitative In Vivo SPECT/CT Imaging Study of Liposomes Using the Novel Iminothiolane-99mTc-Tricarbonyl Complex

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Zoltán Varga ◽  
Imola Cs. Szigyártó ◽  
István Gyurkó ◽  
Rita Dóczi ◽  
Ildikó Horváth ◽  
...  
Keyword(s):  
Specific Activity ◽  
Nuclear Imaging ◽  
Imaging Study ◽  
Size Exclusion ◽  
In Vivo Studies ◽  
The Novel ◽  
Tricarbonyl Complex ◽  
Biodistribution Studies ◽  
Exclusion Chromatography

The in vivo biodistribution of liposomal formulations greatly influences the pharmacokinetics of these novel drugs; therefore the radioisotope labeling of liposomes and the use of nuclear imaging methods for in vivo studies are of great interest. In the present work, a new procedure for the surface labeling of liposomes is presented using the novel 99mTc-tricarbonyl complex. Liposomes mimicking the composition of two FDA approved liposomal drugs were used. In the first step of the labeling, thiol-groups were formed on the surface of the liposomes using Traut’s reagent, which were subsequently used to bind 99mTc-tricarbonyl complex to the liposomal surface. The labeling efficiency determined by size exclusion chromatography was 95%, and the stability of the labeled liposomes in bovine serum was found to be 94% over 2 hours. The obtained specific activity was 50 MBq per 1 μmol lipid which falls among the highest values reported for 99mTc labeling of liposomes. Quantitative in vivo SPECT/CT biodistribution studies revealed distinct differences between the labeled liposomes and the free 99mTc-tricarbonyl, which indicates the in vivo stability of the labeling. As the studied liposomes were non-PEGylated, fast clearance from the blood vessels and high uptake in the liver and spleen were observed.

scholarly journals Evaluation of Organo [18F]Fluorosilicon Tetrazine as a Prosthetic Group for the Synthesis of PET Radiotracers

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1208 ◽  
Author(s):  
Sofia Otaru ◽  
Surachet Imlimthan ◽  
Mirkka Sarparanta ◽  
Kerttuli Helariutta ◽  
Kristiina Wähälä ◽  
...  
Keyword(s):  
Radiochemical Yield ◽  
Biological Evaluation ◽  
Prosthetic Group ◽  
Molar Activity ◽  
Positron Emission ◽  
Biological Studies ◽  
Model Protein ◽  
Improved Stability

Fluorine-18 is the most widely used positron emission tomography (PET) radionuclide currently in clinical application, due to its optimal nuclear properties. The synthesis of 18F-labeled radiotracers often requires harsh reaction conditions, limiting the use of sensitive bio- and macromolecules as precursors for direct radiolabeling with fluorine-18. We aimed to develop a milder and efficient in vitro and in vivo labeling method for trans-cyclooctene (TCO) functionalized proteins, through the bioorthogonal inverse-electron demand Diels-Alder (IEDDA) reaction with fluorine-18 radiolabeled tetrazine ([18F]SiFA-Tz). Here, we used TCO-modified bovine serum albumin (BSA) as the model protein, and isotopic exchange (IE) (19F/18F) chemistry as the labeling strategy. The radiolabeling of albumin-TCO with [18F]SiFA-Tz ([18F]6), providing [18F]fluoroalbumin ([18F]10) in high radiochemical yield (99.1 ± 0.2%, n = 3) and a molar activity (MA) of 1.1 GBq/µmol, confirmed the applicability of [18F]6 as a quick in vitro fluorination reagent for the TCO functionalized proteins. While the biological evaluation of [18F]6 demonstrated defluorination in vivo, limiting the utility for pretargeted applications, the in vivo stability of the radiotracer was dramatically improved when [18F]6 was used for the radiolabeling of albumin-TCO ([18F]10) in vitro, prior to administration. Due to the detected defluorination in vivo, structural optimization of the prosthetic group for improved stability is needed before further biological studies and application of pretargeted PET imaging.

High non-specific binding of the β1-selective radioligand 2-125I-ICI-H

2003 ◽  
Vol 42 (04) ◽  
pp. 173-180 ◽  
Author(s):  
M. P. Law ◽  
K. Kopka ◽  
St. Wagner ◽  
S. Luthra ◽  
V. W. Pike ◽  
...  
Keyword(s):  
Specific Activity ◽  
Single Photon ◽  
Specific Binding ◽  
Photon Emission ◽  
Radiochemical Yield ◽  
Emission Computed Tomography ◽  
Biodistribution Studies ◽  
Positron Emission

Summary: Aim: As results of cardiac biopsies suggest, myocardial β1-adrenoceptor density is reduced in patients with chronic heart failure. However, changes in cardiac β2-adrenoceptors vary. With suitable radiopharmaceuticals single photon emission computed tomography (SPECT) and positron emission tomography (PET) offer the opportunity to assess β-adrenoceptors non-invasively. Among the novel racemic analogues of the established β1-selective adrenoceptor antagonist ICI 89.406 the iodinated 2-I-ICI-H showed high affinity and selectivity to β1-adrenoceptors in murine ventricular membranes. The aim of this study was its evaluation as a putative sub-type selective β1-adrenergic radioligand in cardiac imaging. Methods: Competition studies in vitro and in vivo were used to investigate the kinetics of 2-I-ICI-H binding to cardiac β-adrenoceptors in mice and rats. In addition, the radiosynthesis of 2-125I-ICI-H from the silylated precursor 2-SiMe3-ICI-H was established. The specific activity was 80 GBq/µmol, the radiochemical yield ranged from 70 to 80%. Results: The unlabelled compound 2-I-ICI-H showed high β1-selectivity and -affinity in the in vitro competition studies. In vivo biodistribution studies apparently showed low affinity to cardiac β-adrenoceptors. The radiolabelled counterpart 2-125I-ICI-H showed a high degree of non-specific binding in vitro and no specific binding to cardiac β1-adrenoceptors in vivo. Conclusion: Because of its high non-specific binding 2-125I-ICI-H is no suitable radiotracer for imaging in vivo.

scholarly journals Lack of association between the serotonin transporter and serotonin 1A receptor: an in vivo PET imaging study in healthy adults

2016 ◽  
Vol 255 ◽  
pp. 81-86 ◽  
Author(s):  
Michael Strupp-Levitsky ◽  
Jeffrey M. Miller ◽  
Harry Rubin-Falcone ◽  
Francesca Zanderigo ◽  
Matthew S. Milak ◽  
...  
Keyword(s):  
Serotonin Transporter ◽  
Pet Imaging ◽  
Imaging Study ◽  
Healthy Adults ◽  
Serotonin 1A Receptor
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