A Rapid and Specific HPLC Method to Determine Chemical and Radiochemical Purity of [68Ga] Ga-DOTA-Pentixafor (PET) Tracer: Development and Validation

2020 ◽  
Vol 13 ◽  
Author(s):  
Silvia Migliari ◽  
Antonino Sammartano ◽  
Maura Scarlattei ◽  
Giorgio Baldari ◽  
Claudia Silva ◽  
...  
Keyword(s):  
Standard Procedure ◽  
Hplc Method ◽  
Test Method ◽  
Preparation Conditions ◽  
Pet Tracer ◽  
Positron Emission ◽  
Tumor Types ◽  
Chemokine Receptor 4

Background: Due to its overexpression in a variety of tumor types, the chemokine receptor 4 (CXCR4) represents a highly relevant diagnostic and therapeutic target in nuclear oncology. Recently, [68Ga]Ga-DOTA-Pentixafor has emerged as an excellent imaging agent for positron emission tomography (PET) of CXCR4 expression in vivo. Preparation conditions may influence the quality and in vivo behaviour of this tracer and no standard procedure for the quality controls (QCs) is available. Objective: The developed analytical test method was validated because a specific monograph in the Pharmacopoeia is not available for [68Ga]Ga-DOTA-Pentixafor. Method: A stepwise approach was used, based on the quality by design (QbD) concept of the ICH Q2 (R1) and Q8 (Pharmaceutical Development) guidelines in accordance with the regulations and requirements of EANM, SNM, IAEA and WHO. Results: The purity and quality of the radiopharmaceutical obtained according to the proposed method resulted high enough to safely administrate it to patients. Excellent linearity was found between 0.5 and 4 μg/mL, with a correlation coefficient (r2 ) for calibration curves equal to 0.999, average coefficient of variation (CV%) < 2% and average bias% that doesn't deviate more than 5% for all concentrations. Conclusion: This study developed a new rapid and simple HPLC method of analysis for the routine QCs of [68Ga]GaDOTA-Pentixafor to guarantee the high quality of the finished product before release.

scholarly journals Development and Validation of an Analytical HPLC Method to Assess Chemical and Radiochemical Purity of [68Ga]Ga-NODAGA-Exendin-4 Produced by a Fully Automated Method

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 543
Author(s):  
Silvia Migliari ◽  
Antonino Sammartano ◽  
Marti Boss ◽  
Martin Gotthardt ◽  
Maura Scarlattei ◽  
...  
Keyword(s):  
Radiochemical Purity ◽  
Cell Mass ◽  
Hplc Method ◽  
European Medicines Agency ◽  
Guidance Document ◽  
Limit Of Quantification ◽  
Technical Requirements ◽  
Automated Method ◽  
Pet Tracer

Background: Glucagon-like peptide 1 receptor (GLP-1R) is preferentially expressed in pancreatic islets, especially in β-cells, and highly expressed in human insulinomas and gastrinomas. In recent years several GLP-1R–avid radioligands have been developed to image insulin-secreting tumors or to provide a tentative quantitative in vivo biomarker of pancreatic β-cell mass. Exendin-4, a 39-amino acid peptide with high binding affinity to GLP-1R, has been labeled with Ga-68 for imaging with positron emission tomography (PET). Preparation conditions may influence the quality and in vivo behavior of tracers. Starting from a published synthesis and quality controls (QCs) procedure, we have developed and validated a new rapid and simple UV-Radio-HPLC method to test the chemical and radiochemical purity of [68Ga]Ga-NODAGA-exendin-4, to be used in the clinical routine. Methods: Ga-68 was obtained from a 68Ge/68Ga Generator (GalliaPharma®) and purified using a cationic-exchange cartridge on an automated synthesis module (Scintomics GRP®). NODAGA-exendin-4 contained in the reactor (10 µg) was reconstituted with HEPES and ascorbic acid. The reaction mixture was incubated at 100 °C. The product was purified through HLB cartridge, diluted, and sterilized. To validate the proposed UV-Radio-HPLC method, a stepwise approach was used, as defined in the guidance document released by the International Conference on Harmonization of Technical Requirements of Pharmaceuticals for Human Use (ICH), adopted by the European Medicines Agency (CMP/ICH/381/95 2014). The assessed parameters are specificity, linearity, precision (repeatability), accuracy, and limit of quantification. Therefore, a range of concentrations of Ga-NODAGA-exendin-4, NODAGA-exendin-4 (5, 4, 3.125, 1.25, 1, and 0.75 μg/mL) and [68Ga]Ga-NODAGA-exendin-4 were analyzed. To validate the entire production process, three consecutive batches of [68Ga]Ga-NODAGA-exendin-4 were tested. Results: Excellent linearity was found between 5–0.75 μg/mL for both the analytes (NODAGA-exendin-4 and 68Ga-NODAGA-exendin-4), with a correlation coefficient (R2) for calibration curves equal to 0.999, average coefficients of variation (CV%) <2% (0.45% and 0.39%) and average per cent deviation value of bias from 100%, of 0.06% and 0.04%, respectively. The calibration curve for the determination of [68Ga]Ga-NODAGA-exendin-4 was linear with a R2 of 0.993 and CV% <2% (1.97%), in accordance to acceptance criteria. The intra-day and inter-day precision of our method was statistically confirmed using 10 μg of peptide. The mean radiochemical yield was 45 ± 2.4% in all the three validation batches of [68Ga]Ga-NODAGA-exendin-4. The radiochemical purity of [68Ga]Ga-NODAGA-exendin-4 was >95% (97.05%, 95.75% and 96.15%) in all the three batches. Conclusions: The developed UV-Radio-HPLC method to assess the radiochemical and chemical purity of [68Ga]Ga-NODAGA-exendin-4 is rapid, accurate and reproducible like its fully automated production. It allows the routine use of this PET tracer as a diagnostic tool for PET imaging of GLP-1R expression in vivo, ensuring patient safety.

scholarly journals 11C-Labeled Pictilisib (GDC-0941) as a Molecular Tracer Targeting Phosphatidylinositol 3-Kinase (PI3K) for Breast Cancer Imaging

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Na Han ◽  
Yaqun Jiang ◽  
Yongkang Gai ◽  
Qingyao Liu ◽  
Lujie Yuan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Pik3ca Mutation ◽  
Phosphatidylinositol 3 Kinase ◽  
Pet Tracer ◽  
Positron Emission ◽  
Pet Scans ◽  
Mcf 7 ◽  
Phosphatidylinositol 3

Pictilisib (GDC-0941) is an inhibitor of phosphatidylinositol 3-kinase (PI3K), part of a signaling cascade involved in breast cancer development. The purpose of this study was to evaluate the pharmacokinetics of pictilisib noninvasively by radiolabeling it with 11C and to assess the usability of the resulting [11C]-pictilisib as a positron-emission tomography (PET) tracer to screen for pictilisib-sensitive tumors. In this study, pictilisib was radiolabeled with [11C]-methyl iodide to obtain 11C-methylated pictilisib ([11C]-pictilisib) using an automated synthesis module with a high radiolabeling yield. Considerably higher uptake ratios were observed in MCF-7 (PIK3CA mutation, pictilisib-sensitive) cells than those in MDA-MB-231 (PIK3CA wild-type, pictilisib-insensitive) cells at all evaluated time points, indicating good in vitro binding of [11C]-pictilisib. Dynamic micro-PET scans in mice and biodistribution results showed that [11C]-pictilisib was mainly excreted via the hepatobiliary tract into the intestines. MCF-7 xenografts could be clearly visualized on the static micro-PET scans, while MDA-MB-231 tumors could not. Biodistribution results of two xenograft models showed significantly higher uptake and tumor-to-muscle ratios in the MCF-7 xenografts than those in MDA-MB-231 xenografts, exhibiting high in vivo targeting specificity. In conclusion, [11C]-pictilisib was first successfully prepared, and it exhibited good potential to identify pictilisib-sensitive tumors noninvasively, which may have a great impact in the treatment of cancers with an overactive PI3K/Akt/mTOR signal pathway. However, the high activity in hepatobiliary system and intestines needs to be addressed.

scholarly journals Automated Synthesis of Fluorine-18 Labeled CXCR4 Ligand via the Conjugation with Nicotinic Acid N-Hydroxysuccinimide Ester (6-[18F]SFPy)

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3924
Author(s):  
Falguni Basuli ◽  
Xiang Zhang ◽  
Tim E. Phelps ◽  
Elaine M. Jagoda ◽  
Peter L. Choyke ◽  
...  
Keyword(s):  
Nicotinic Acid ◽  
Specific Binding ◽  
Automated Synthesis ◽  
Bone Marrow Niche ◽  
Positron Emission ◽  
Straightforward Method ◽  
Radiochemical Yields ◽  
Chemokine Receptor 4

The C-X-C motif chemokine receptor 4 (CXCR4) is a seven-transmembrane G protein-coupled receptor that is overexpressed in numerous diseases, particularly in various cancers and is a powerful chemokine, attracting cells to the bone marrow niche. Therefore, CXCR4 is an attractive target for imaging and therapeutic purposes. The goal of this study is to develop an efficient, reproducible, and straightforward method to prepare a fluorine-18 labeled CXCR4 ligand. 6-[18F]Fluoronicotinic acid-2,3,5,6-tetrafluorophenyl ester (6-[18F]FPy-TFP) and nicotinic acid N-hydroxysuccinimide ester (6-[18F]SFPy) have been prepared using ‘fluorination on the Sep-Pak’ method. Conjugation of 6-[18F]SFPy or 6-[18F]FPy-TFP with the alpha-amino group at the N terminus of the protected T140 precursor followed by deprotection, yielded the final product 6-[18F]FPy-T140. The overall radiochemical yields were 6–17% (n = 15, decay-corrected) in a 90-min radiolabeling time with a radiochemical purity >99%. 6-[18F]FPy-T140 exhibited high specific binding and nanomolar affinity for CXCR4 in vitro, indicating that the biological activity of the peptide was preserved. For the first time, [18F]SFPy has been prepared using ‘fluorination on the Sep-Pak’ method that allows rapid automated synthesis of 6-[18F]FPy-T140. In addition to increased synthetic efficiency, this construct binds with CXCR4 in high affinity and may have potential as an in vivo positron emission tomography (PET) imaging agent. This radiosynthesis method should encourage wider use of this PET agent to quantify CXCR4 in both research and clinical settings.

scholarly journals Quantification of [11C]PIB PET for Imaging Myelin in the Human Brain: A Test—Retest Reproducibility Study in High-Resolution Research Tomography

2015 ◽  
Vol 35 (11) ◽  
pp. 1771-1782 ◽  
Author(s):  
Mattia Veronese ◽  
Benedetta Bodini ◽  
Daniel García-Lorenzo ◽  
Marco Battaglini ◽  
Salvatore Bongarzone ◽  
...  
Keyword(s):  
High Resolution ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Volume Ratio ◽  
Reference Region ◽  
Brain White Matter ◽  
Reproducibility Study ◽  
Pet Tracer ◽  
Positron Emission

An accurate in vivo measure of myelin content is essential to deepen our insight into the mechanisms underlying demyelinating and dysmyelinating neurological disorders, and to evaluate the effects of emerging remyelinating treatments. Recently [11C]PIB, a positron emission tomography (PET) tracer originally conceived as a beta-amyloid marker, has been shown to be sensitive to myelin changes in preclinical models and humans. In this work, we propose a reference-region methodology for the voxelwise quantification of brain white-matter (WM) binding for [11C]PIB. This methodology consists of a supervised procedure for the automatic extraction of a reference region and the application of the Logan graphical method to generate distribution volume ratio (DVR) maps. This approach was assessed on a test–retest group of 10 healthy volunteers using a high-resolution PET tomograph. The [11C]PIB PET tracer binding was shown to be up to 23% higher in WM compared with gray matter, depending on the image reconstruction. The DVR estimates were characterized by high reliability (outliers < 1%) and reproducibility (intraclass correlation coefficient (ICC) > 0.95). [11C]PIB parametric maps were also found to be significantly correlated ( R2 > 0.50) to mRNA expressions of the most represented proteins in the myelin sheath. On the contrary, no correlation was found between [11C]PIB imaging and nonmyelin-associated proteins.

scholarly journals [18F]MK-9470, a positron emission tomography (PET) tracer for in vivo human PET brain imaging of the cannabinoid-1 receptor

2007 ◽  
Vol 104 (23) ◽  
pp. 9800-9805 ◽  
Author(s):  
H. D. Burns ◽  
K. Van Laere ◽  
S. Sanabria-Bohorquez ◽  
T. G. Hamill ◽  
G. Bormans ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Brain Imaging ◽  
Emission Tomography ◽  
Cannabinoid 1 Receptor ◽  
Pet Tracer ◽  
Positron Emission

scholarly journals A 11C-Labeled 1,4-Dihydroquinoline Derivative as a Potential PET Tracer for Imaging of Redox Status in Mouse Brain

2015 ◽  
Vol 35 (12) ◽  
pp. 1930-1936 ◽  
Author(s):  
Toshimitsu Okamura ◽  
Maki Okada ◽  
Tatsuya Kikuchi ◽  
Hidekatsu Wakizaka ◽  
Ming-Rong Zhang
Keyword(s):  
Mouse Brain ◽  
Initial Velocity ◽  
Brain Homogenate ◽  
Redox Balance ◽  
Redox Status ◽  
Cationic Form ◽  
Pet Tracer ◽  
Positron Emission ◽  
The Brain

A disturbance in redox balance has been implicated in the pathogenesis of a number of diseases. This study sought to examine the feasibility of imaging brain redox status using a 11C-labeled dihydroquinoline derivative ([11C]DHQ1) for positron emission tomography (PET). The lipophilic PET tracer [11C]DHQ1 was rapidly oxidized to its hydrophilic form in mouse brain homogenate. The redox modulators diphenyleneiodonium and apocynin significantly reduced the initial velocity of [11C]DHQ1 oxidation, and apocynin also caused concentration-dependent inhibition of the initial velocity. Moreover, [11C]DHQ1 readily entered the brain by diffusion after administration and underwent oxidation into the hydrophilic cationic form, which then slowly decreased. By contrast, apocynin treatment inhibited the in vivo oxidation of [11C]DHQ1 to the hydrophilic cationic form, leading to a rapid decrease of radioactivity in the brain. Thus, the difference in the [11C]DHQ1 kinetics reflects the alteration in redox status caused by apocynin. In conclusion, [11C]DHQ1 is a potential PET tracer for imaging of redox status in the living brain.

scholarly journals Synthesis and Preclinical Evaluation of [18F]PF04217903, a Selective MET PET Tracer

2020 ◽  
Author(s):  
Vegard Torp Lien ◽  
Emily Hauge ◽  
Syed Nuruddin ◽  
Jo Klaveness ◽  
Dag Erlend Olberg
Keyword(s):  
Growth Factor Receptor ◽  
Radiochemical Yield ◽  
Molar Activity ◽  
Bioisosteric Replacement ◽  
Pet Tracer ◽  
Positron Emission ◽  
Wide Range ◽  
Hepatocyte Growth

<p>The tyrosine kinase MET (hepatocyte growth factor receptor) is abnormally activated in a wide range of cancers and is often correlated with a poor prognosis. Precision medicine with positron emission tomography (PET) can potentially aid in the assessment of tumor biochemistry and heterogeneity, which can prompt the selection of the most effective therapeutic regimes. The selective MET inhibitor PF04217903 (<b>1</b>) formed the basis for a bioisosteric replacement to the deoxyfluorinated analogue [<sup>18</sup>F]<b>2</b>, intended as a PET tracer for MET. [<sup>18</sup>F]<b>2 </b>could be synthesized with a “hydrous fluoroethylation” protocol in 6.3 ± 2.6% radiochemical yield and a molar activity of >50 GBq/µmol. <i>In vitro</i> autoradiography indicated that [<sup>18</sup>F]<b>2 </b>specifically binds to MET in PC3 tumor tissue, and <i>in vivo</i> biodistribution in mice showed predominantly a hepatobiliary excretion along with a low retention of radiotracer in other organs. </p>

scholarly journals 89Zr-Labeled AR20.5: A MUC1-Targeting ImmunoPET Probe

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2315 ◽  
Author(s):  
Kimberly Fung ◽  
Delphine Vivier ◽  
Outi Keinänen ◽  
Elaheh Khozeimeh Sarbisheh ◽  
Eric W. Price ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Tissue ◽  
Activity Concentration ◽  
Poor Response ◽  
Response To Therapy ◽  
In Vivo Evaluation ◽  
In Vivo Experiments ◽  
Positron Emission ◽  
Tumor Types

High expression levels of the tumor-associated antigen MUC1 have been correlated with tumor aggressiveness, poor response to therapy, and poor survival in several tumor types, including breast, pancreatic, and epithelial ovarian cancer. Herein, we report the synthesis, characterization, and in vivo evaluation of a novel radioimmunoconjugate for the immuno-positron emission tomography (immunoPET) imaging of MUC1 expression based on the AR20.5 antibody. To this end, we modified AR20.5 with the chelator desferrioxamine (DFO) and labeled it with the positron-emitting radiometal zirconium-89 (t1/2 ~3.3 d) to produce [89Zr]Zr-DFO-AR20.5. In subsequent in vivo experiments in athymic nude mice bearing subcutaneous MUC1-expressing ovarian cancer xenografts, [89Zr]Zr-DFO-AR20.5 clearly delineated tumor tissue, producing a tumoral activity concentration of 19.1 ± 6.4 percent injected dose per gram (%ID/g) at 120 h post-injection and a tumor-to-muscle activity concentration ratio of 42.4 ± 10.6 at the same time point. Additional PET imaging experiments in mice bearing orthotopic MUC1-expressing ovarian cancer xenografts likewise demonstrated that [89Zr]Zr-DFO-AR20.5 enables the visualization of tumor tissue—including metastatic lesions—with promising tumor-to-background contrast.

scholarly journals [18F]Fluoroethyltriazolyl Monocyclam Derivatives as Imaging Probes for the Chemokine Receptor CXCR4

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1612 ◽  
Author(s):  
Alejandro Amor-Coarasa ◽  
James M. Kelly ◽  
Pradeep K. Singh ◽  
Shashikanth Ponnala ◽  
Anastasia Nikolopoulou ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Cxcr4 Expression ◽  
Tumor Uptake ◽  
Multiple Tumor ◽  
Chemokine Receptor Cxcr4 ◽  
Positron Emission ◽  
Imaging Probes ◽  
High Tumor Uptake ◽  
Tumor Types

Determining chemokine receptor CXCR4 expression is significant in multiple diseases due to its role in promoting inflammation, cell migration and tumorigenesis. [68Ga]Pentixafor is a promising ligand for imaging CXCR4 expression in multiple tumor types, but its utility is limited by the physical properties of 68Ga. We screened a library of >200 fluorine-containing structural derivatives of AMD-3465 to identify promising candidates for in vivo imaging of CXCR4 expression by positron emission tomography (PET). Compounds containing fluoroethyltriazoles consistently achieved higher docking scores. Six of these higher scoring compounds were radiolabeled by click chemistry and evaluated in PC3-CXCR4 cells and BALB/c mice bearing bilateral PC3-WT and PC3-CXCR4 xenograft tumors. The apparent CXCR4 affinity of the ligands was relatively low, but tumor uptake was CXCR4-specific. The tumor uptake of [18F]RPS-534 (7.2 ± 0.3 %ID/g) and [18F]RPS-547 (3.1 ± 0.5 %ID/g) at 1 h p.i. was highest, leading to high tumor-to-blood, tumor-to-muscle, and tumor-to-lung ratios. Total cell-associated activity better predicted in vivo tumor uptake than did the docking score or apparent CXCR4 affinity. By this metric, and on the basis of their high yielding radiosynthesis, high tumor uptake, and good contrast to background, [18F]RPS-547, and especially [18F]RPS-534, are promising 18F-labeled candidates for imaging CXCR4 expression.

A SCID Mouse Model for Monitoring in Vivo Viability of Human Platelet Concentrates Using Flow Cytometry

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4549-4549
Author(s):  
Jia-hua Ding ◽  
Cheng-yin Huang ◽  
Shiyun Xu
Keyword(s):  
Flow Cytometry ◽  
Whole Blood ◽  
Human Platelet ◽  
Human Platelets ◽  
Scid Mice ◽  
Test Method ◽  
Platelet Concentrates ◽  
Tail Vein

Abstract Objective To develop an animal test method for evaluating the in vivo quality of human platelet concentrates. Methods Human platelets were transfused to mice by tail vein with a 1mL insulin syring fitted with a 29-gauge ultra-fine needle. Blood samples were taken at 30 minutes,2,4,6,8,12, and 24hours after infusion with a tail vein nick technique, whole blood was collected into heparinized capillary tubes. Human platelets in mouse whole blood were detected by flow cytometry with monoclonal anti-human CD61-PE–conjugated antibodies. All subsequent recoveries were calculated as a percentage of the initial collection. Results The survival time of human platelets were significantly prolonged in SCID than in BALB/c,FVB mice. Recoveries at 4 hours after transfusion in SCID, BALB/c,FVB mice were 68.6%±8.1%(n =10),29.9%±6.5%(n =8),28.1%±5.5%(n =8), respectively, and with a T½ estimate of 8 hours for SCID, 2.5 hours for BALB/c and 2 hours for FVB mice. platelet storage lesions either by chemical treatment or by suboptimal conditions storage exhibited decreased recoveries in SCID mice. Conclusion The quality of platelet Products can be evaluated by assessing the survival of human platelets in SCID mice using flow cytometry.

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