1
|
Eriksson O, Velikyan I. Radiotracers for Imaging of Fibrosis: Advances during the Last Two Decades and Future Directions. Pharmaceuticals (Basel) 2023; 16:1540. [PMID: 38004406 PMCID: PMC10674214 DOI: 10.3390/ph16111540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/13/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
Fibrosis accompanies various pathologies, and there is thus an unmet medical need for non-invasive, sensitive, and quantitative methods for the assessment of fibrotic processes. Currently, needle biopsy with subsequent histological analysis is routinely used for the diagnosis along with morphological imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US). However, none of these imaging techniques are sufficiently sensitive and accurate to detect minor changes in fibrosis. More importantly, they do not provide information on fibrotic activity on the molecular level, which is critical for fundamental understanding of the underlying biology and disease course. Molecular imaging technology using positron emission tomography (PET) offers the possibility of imaging not only physiological real-time activity, but also high-sensitivity and accurate quantification. This diagnostic tool is well established in oncology and has exhibited exponential development during the last two decades. However, PET diagnostics has only recently been widely applied in the area of fibrosis. This review presents the progress of development of radiopharmaceuticals for non-invasive detection of fibrotic processes, including the fibrotic scar itself, the deposition of new fibrotic components (fibrogenesis), or the degradation of existing fibrosis (fibrolysis).
Collapse
Affiliation(s)
- Olof Eriksson
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, 751 83 Uppsala, Sweden;
- Antaros Tracer AB, Dragarbrunnsgatan 46, 2 tr, 753 20 Uppsala, Sweden
| | - Irina Velikyan
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, 751 83 Uppsala, Sweden;
- Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala University, 752 85 Uppsala, Sweden
| |
Collapse
|
2
|
Stendahl JC, Kwan JM, Pucar D, Sadeghi MM. Radiotracers to Address Unmet Clinical Needs in Cardiovascular Imaging, Part 2: Inflammation, Fibrosis, Thrombosis, Calcification, and Amyloidosis Imaging. J Nucl Med 2022; 63:986-994. [PMID: 35772956 PMCID: PMC9258561 DOI: 10.2967/jnumed.121.263507] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 02/22/2022] [Indexed: 01/03/2023] Open
Abstract
Cardiovascular imaging is evolving in response to systemwide trends toward molecular characterization and personalized therapies. The development of new radiotracers for PET and SPECT imaging is central to addressing the numerous unmet diagnostic needs that relate to these changes. In this 2-part review, we discuss select radiotracers that may help address key unmet clinical diagnostic needs in cardiovascular medicine. Part 1 examined key technical considerations pertaining to cardiovascular radiotracer development and reviewed emerging radiotracers for perfusion and neuronal imaging. Part 2 covers radiotracers for imaging cardiovascular inflammation, thrombosis, fibrosis, calcification, and amyloidosis. These radiotracers have the potential to address several unmet needs related to the risk stratification of atheroma, detection of thrombi, and the diagnosis, characterization, and risk stratification of cardiomyopathies. In the first section, we discuss radiotracers targeting various aspects of inflammatory responses in pathologies such as myocardial infarction, myocarditis, sarcoidosis, atherosclerosis, and vasculitis. In a subsequent section, we discuss radiotracers for the detection of systemic and device-related thrombi, such as those targeting fibrin (e.g., 64Cu-labeled fibrin-binding probe 8). We also cover emerging radiotracers for the imaging of cardiovascular fibrosis, such as those targeting fibroblast activation protein (e.g., 68Ga-fibroblast activation protein inhibitor). Lastly, we briefly review radiotracers for imaging of cardiovascular calcification (18F-NaF) and amyloidosis (e.g., 99mTc-pyrophosphate and 18F-florbetapir).
Collapse
Affiliation(s)
- John C Stendahl
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Jennifer M Kwan
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Darko Pucar
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut; and
| | - Mehran M Sadeghi
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut;
- Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| |
Collapse
|
3
|
Velikyan I, Rosenström U, Rosestedt M, Eriksson O, Antoni G. Improved Radiolytic Stability of a 68Ga-labelled Collagelin Analogue for the Imaging of Fibrosis. Pharmaceuticals (Basel) 2021; 14:990. [PMID: 34681214 PMCID: PMC8537947 DOI: 10.3390/ph14100990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/22/2021] [Accepted: 09/22/2021] [Indexed: 11/29/2022] Open
Abstract
There is an unmet medical need for non-invasive, sensitive, and quantitative methods for the assessment of fibrosis. Herein, an improved collagelin analogue labelled with gallium-68 for use with positron emission tomography (PET) is presented. A cyclic peptide, c[CPGRVNleHGLHLGDDEGPC], was synthesized by solid-phase peptide synthesis, conjugated to 2-(4,7-bis(2-(tert-butoxy)-2-oxoethyl)-1,4,7-triazonan-1-yl)acetic acid, and labelled with gallium-68. High performance liquid chromatography (HPLC) was used for the quality and stability assessment of the collagelin analogue. Non-specific organ distribution, blood clearance, and excretion rates were investigated in healthy mice and rats using ex vivo organ distribution analysis and dynamic in vivo PET/CT. Mice with carbon tetrachloride (CCl4) induced liver fibrosis were used for the investigation of specific binding via in vitro frozen section autoradiography, ex vivo organ distribution, and in vivo PET/CT. A non-decay corrected radiochemical yield (48 ± 6%) of [68Ga]Ga-NOTA-PEG2-c[CPGRVNleHGLHLGDDEGPC] ([68Ga]Ga-NO2A-[Nle13]-Col) with a radiochemical purity of 98 ± 2% was achieved without radical scavengers. The 68Ga-labelling was regioselective and stable at ambient temperature for at least 3 h. The autoradiography of the cryosections of fibrotic mouse liver tissue demonstrated a distinct heterogeneous radioactivity uptake that correlated with the fibrosis scores estimated after Sirius Red staining. The blood clearance and tissue washout from the [68Ga]Ga-NO2A-[Nle13]-Col was fast in both normal and diseased mice. Dosimetry investigation in rats indicated the possibility for 4-5 PET/CT examinations per year. Radiolytic stability of the collagelin analogue was achieved by the substitution of methionine with norleucine amino acid residue without a deterioration of its binding capability. [68Ga]Ga-NO2A-[Nle13]-Col demonstrated a safe dosimetry profile suitable for repeated scanning.
Collapse
Affiliation(s)
- Irina Velikyan
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, SE-75183 Uppsala, Sweden; (M.R.); (O.E.)
- PET-Centre, Centre for Medical Imaging, Uppsala University Hospital, SE-75185 Uppsala, Sweden
| | - Ulrika Rosenström
- Department of Medicinal Chemistry, Uppsala University, SE-75123 Uppsala, Sweden;
| | - Maria Rosestedt
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, SE-75183 Uppsala, Sweden; (M.R.); (O.E.)
| | - Olof Eriksson
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, SE-75183 Uppsala, Sweden; (M.R.); (O.E.)
| | - Gunnar Antoni
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, SE-75183 Uppsala, Sweden; (M.R.); (O.E.)
- PET-Centre, Centre for Medical Imaging, Uppsala University Hospital, SE-75185 Uppsala, Sweden
| |
Collapse
|
4
|
Rosestedt M, Velikyan I, Rosenström U, Estrada S, Åberg O, Weis J, Westerlund C, Ingvast S, Korsgren O, Nordeman P, Eriksson O. Radiolabelling and positron emission tomography imaging of a high-affinity peptide binder to collagen type 1. Nucl Med Biol 2020; 93:54-62. [PMID: 33321470 DOI: 10.1016/j.nucmedbio.2020.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/23/2020] [Accepted: 11/22/2020] [Indexed: 01/18/2023]
Abstract
INTRODUCTION Pathological formation of fibrosis, is an important feature in many diseases. Fibrosis in liver and pancreas has been associated to metabolic disease including type 1 and 2 diabetes. The current methods for detecting and diagnosing fibrosis are either invasive, or their sensitivity to detect fibrosis in early stage is limited. Therefore, it is crucial to develop non-invasive methods to detect, stage and study the molecular processes that drive the pathology of liver fibrosis. The peptide LRELHLNNN was previously identified as a selective binder to collagen type I with an affinity of 170 nM. Radiolabelled LRELHLNNN thus constitute a potential PET tracer for fibrosis. METHOD LRELHLNNN was conjugated to a DOTA/NOTA moiety via a PEG2-linker. DOTA-PEG2-LRELHLNNN was labelled with Gallium-68 and NOTA- PEG2-LRELHLNNN with aluminium fluoride-18. Biodistribution of [68Ga]Ga-DOTA-PEG2-LRELHLNNN and [18F]AlF-NOTA-PEG2-LRELHLNNN was performed in healthy rats ex vivo and in vivo. The 68Ga-labelled analogue was evaluated in a mouse model of liver fibrosis by PET/MRI-imaging. The human predicted dosimetry of the tracers was extrapolated from rat ex vivo biodistribution studies at 10, 20, 40, 60, 120, 180 min (only fluoride-18) post-injection. RESULTS The peptides were successfully radiolabelled with gallium-68 and aluminium fluoride-18, respectively. The biodistribution of [68Ga]Ga-DOTA-PEG2-LRELHLNNN and [18F]AlF-NOTA-PEG2-LRELHLNNN was favorable showing rapid clearance and low background binding in organs where fibrosis may develop. Binding of [68Ga]Ga-DOTA-PEG2-LRELHLNNN to fibrotic liver was higher than surrounding tissues in mice with induced hepatic fibrosis. However, the binding was in the range of SUV 0.3, indicating limited targeting of the tracer to liver. The extrapolated human predicted dosimetric profiles of [68Ga]Ga-DOTA-PEG2-LRELHLNNN and [18F]AlF-NOTA-PEG2-LRELHLNNN were beneficial, potentially allowing at least three PET examinations annually. CONCLUSIONS We describe the modification, radiolabelling and evaluation of the collagen type I binding peptide LRELHLNNN. The resulting radiotracer analogues demonstrated suitable biodistribution and dosimetry. [68Ga]Ga-DOTA-PEG2-LRELHLNNN exhibited binding to hepatic fibrotic lesions and is a promising tool for PET imaging of fibrosis. ADVANCES IN KNOWLEDGE Validation of a new collagen targeting PET tracer. IMPLICATIONS FOR PATIENT CARE Early, non-invasive diagnosis and stratification of fibrosis in order to improve the diagnosis, staging and treatment of patients with diseases involving fibrosis.
Collapse
Affiliation(s)
- Maria Rosestedt
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Irina Velikyan
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Ulrika Rosenström
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Sergio Estrada
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Ola Åberg
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Jan Weis
- Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden
| | | | - Sofie Ingvast
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Patrik Nordeman
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Olof Eriksson
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden; Antaros Medical AB, Mölndal, Sweden.
| |
Collapse
|
5
|
Bengel FM, Ross TL. Emerging imaging targets for infiltrative cardiomyopathy: Inflammation and fibrosis. J Nucl Cardiol 2019; 26:208-216. [PMID: 29968156 DOI: 10.1007/s12350-018-1356-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 12/11/2022]
Abstract
Molecular imaging in infiltrative cardiomyopathies is increasingly penetrating the clinical arena. Current approaches target the infiltrate directly, or its metabolic, physiologic, or functional consequences. Inflammation may not just play a role as the infiltrative mechanism itself. It is also thought to play a key role in the development and progression of heart failure in general, because it promotes the development of tissue fibrosis. The cascade leading from tissue damage to inflammation and further to fibrosis and loss of function has emerged as a therapeutic target. This review focuses (1) on novel tracers of inflammation, which are on the brink of clinical applicability and may be more specific than the gross metabolic marker F-18 deoxyglucose; and (2) on novel biologic imaging targets in fibrosis, which may be exploited for interrogation of the crosstalk between inflammation and loss of contractile function. Ultimately, the success of any novel molecular imaging assay will depend on whether it can be used for successful guidance of novel, targeted therapies aiming at tissue regeneration.
Collapse
Affiliation(s)
- Frank M Bengel
- Klinik für Nuklearmedizin, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Tobias L Ross
- Klinik für Nuklearmedizin, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| |
Collapse
|
6
|
Prospective of 68Ga Radionuclide Contribution to the Development of Imaging Agents for Infection and Inflammation. CONTRAST MEDIA & MOLECULAR IMAGING 2018. [PMID: 29531507 PMCID: PMC5817300 DOI: 10.1155/2018/9713691] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
During the last decade, the utilization of 68Ga for the development of imaging agents has increased considerably with the leading position in the oncology. The imaging of infection and inflammation is lagging despite strong unmet medical needs. This review presents the potential routes for the development of 68Ga-based agents for the imaging and quantification of infection and inflammation in various diseases and connection of the diagnosis to the treatment for the individualized patient management.
Collapse
|
7
|
Shirani J, Singh A, Agrawal S, Dilsizian V. Cardiac molecular imaging to track left ventricular remodeling in heart failure. J Nucl Cardiol 2017; 24:574-590. [PMID: 27480973 DOI: 10.1007/s12350-016-0620-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 07/13/2016] [Indexed: 12/11/2022]
Abstract
Cardiac left ventricular (LV) remodeling is the final common pathway of most primary cardiovascular diseases that manifest clinically as heart failure (HF). The more advanced the systolic HF and LV dysfunction, the worse the prognosis. The knowledge of the molecular, cellular, and neurohormonal mechanisms that lead to myocardial dysfunction and symptomatic HF has expanded rapidly and has allowed sophisticated approaches to understanding and management of the disease. New therapeutic targets for pharmacologic intervention in HF have also been identified through discovery of novel cellular and molecular components of membrane-bound receptor-mediated intracellular signal transduction cascades. Despite all advances, however, the prognosis of systolic HF has remained poor in general. This is, at least in part, related to the (1) relatively late institution of treatment due to reliance on gross functional and structural abnormalities that define the "heart failure phenotype" clinically; (2) remarkable genetic-based interindividual variations in the contribution of each of the many molecular components of cardiac remodeling; and (3) inability to monitor the activity of individual pathways to cardiac remodeling in order to estimate the potential benefits of pharmacologic agents, monitor the need for dose titration, and minimize side effects. Imaging of the recognized ultrastructural components of cardiac remodeling can allow redefinition of heart failure based on its "molecular phenotype," and provide a guide to implementation of "personalized" and "evidence-based" evaluation, treatment, and longitudinal monitoring of the disease beyond what is currently available through randomized controlled clinical trials.
Collapse
Affiliation(s)
- Jamshid Shirani
- Department of Cardiology, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA, USA.
| | - Amitoj Singh
- Department of Cardiology, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA, USA
| | - Sahil Agrawal
- Department of Cardiology, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA, USA
| | - Vasken Dilsizian
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|