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The Journal of Clinical Investigation Jan 2019Fibrosis, the progressive accumulation of connective tissue that occurs in response to injury, causes irreparable organ damage and may result in organ failure. The few... (Review)
Review
Fibrosis, the progressive accumulation of connective tissue that occurs in response to injury, causes irreparable organ damage and may result in organ failure. The few available antifibrotic treatments modify the rate of fibrosis progression, but there are no available treatments to reverse established fibrosis. Thus, more effective therapies are urgently needed. Molecular imaging is a promising biomedical methodology that enables noninvasive visualization of cellular and subcellular processes. It provides a unique means to monitor and quantify dysregulated molecular fibrotic pathways in a noninvasive manner. Molecular imaging could be used for early detection, disease staging, and prognostication, as well as for assessing disease activity and treatment response. As fibrotic diseases are often molecularly heterogeneous, molecular imaging of a specific pathway could be used for patient stratification and cohort enrichment with the goal of improving clinical trial design and feasibility and increasing the ability to detect a definitive outcome for new therapies. Here we review currently available molecular imaging probes for detecting fibrosis and fibrogenesis, the active formation of new fibrous tissue, and their application to models of fibrosis across organ systems and fibrotic processes. We provide our opinion as to the potential roles of molecular imaging in human fibrotic diseases.
Topics: Animals; Fibrosis; Humans; Models, Biological; Molecular Imaging
PubMed: 30601139
DOI: 10.1172/JCI122132 -
Current Opinion in Endocrinology,... Feb 2020Neuroendocrine tumors are heterogeneous neoplasms with variable prognoses and clinical behaviors. The majority of well differentiated NETs express somatostatin... (Review)
Review
PURPOSE OF REVIEW
Neuroendocrine tumors are heterogeneous neoplasms with variable prognoses and clinical behaviors. The majority of well differentiated NETs express somatostatin receptors. Identification of these receptors has contributed to advancements in molecular and targeted radiotherapies.
RECENT FINDINGS
Molecular scans provide important diagnostic, staging, and prognostic data. Somatostatin-receptor imaging aids in selection of patients who are eligible for somatostatin-receptor-targeting therapies. Peptide receptor radionuclide therapy has recently demonstrated robust efficacy in a phase III study of progressive midgut NETs. Current studies are investigating novel receptor agonists and antagonists, new classes of radioactive isotopes, and radiosensitizing combination treatments.
SUMMARY
The sophistication of molecular imaging is improving and its importance is increasing as a diagnostic, predictive, and prognostic tool. Theranostics, the coupling of molecular imaging with receptor-targeted therapy, represents a novel approach to cancer treatment.
Topics: Humans; Molecular Imaging; Neoplasm Staging; Neuroendocrine Tumors; Prognosis; Radioisotopes; Receptors, Somatostatin
PubMed: 31789833
DOI: 10.1097/MED.0000000000000519 -
Current Opinion in Chemical Biology Aug 2022
Topics: Molecular Imaging
PubMed: 35696741
DOI: 10.1016/j.cbpa.2022.102168 -
Advanced Drug Delivery Reviews Apr 2017The tumor microenvironment plays a critical role in tumor initiation, progression, metastasis, and resistance to therapy. It is different from normal tissue in the... (Review)
Review
The tumor microenvironment plays a critical role in tumor initiation, progression, metastasis, and resistance to therapy. It is different from normal tissue in the extracellular matrix, vascular and lymphatic networks, as well as physiologic conditions. Molecular imaging of the tumor microenvironment provides a better understanding of its function in cancer biology, and thus allowing for the design of new diagnostics and therapeutics for early cancer diagnosis and treatment. The clinical translation of cancer molecular imaging is often hampered by the high cost of commercialization of targeted imaging agents as well as the limited clinical applications and small market size of some of the agents. Because many different cancer types share similar tumor microenvironment features, the ability to target these biomarkers has the potential to provide clinically translatable molecular imaging technologies for a spectrum of cancers and broad clinical applications. There has been significant progress in targeting the tumor microenvironment for cancer molecular imaging. In this review, we summarize the principles and strategies of recent advances made in molecular imaging of the tumor microenvironment, using various imaging modalities for early detection and diagnosis of cancer.
Topics: Animals; Disease Progression; Early Detection of Cancer; Extracellular Matrix; Humans; Molecular Imaging; Neoplasms; Tumor Microenvironment
PubMed: 27497513
DOI: 10.1016/j.addr.2016.07.012 -
Contrast Media & Molecular Imaging 2018This review focuses on recent advances in the molecular imaging of aminopeptidase N (APN, also known as CD13), a zinc metalloenzyme that cleaves -terminal neutral amino... (Review)
Review
This review focuses on recent advances in the molecular imaging of aminopeptidase N (APN, also known as CD13), a zinc metalloenzyme that cleaves -terminal neutral amino acids. It is overexpressed in multiple cancer types and also on the surface of vasculature undergoing angiogenesis, making it a promising target for molecular imaging and targeted therapy. Molecular imaging probes for APN are divided into two large subgroups: reactive and nonreactive. The structures of the reactive probes (substrates) contain a reporter group that is cleaved and released by the APN enzyme. The nonreactive probes are not cleaved by the enzyme and contain an antibody, peptide, or nonpeptide for targeting the enzyme exterior or active site. Multivalent homotopic probes utilize multiple copies of the same targeting unit, whereas multivalent heterotopic molecular probes are equipped with different targeting units for different receptors. Several recent preclinical cancer imaging studies have shown that multivalent APN probes exhibit enhanced tumor specificity and accumulation compared to monovalent analogues. The few studies that have evaluated APN-specific probes for imaging angiogenesis have focused on cardiac regeneration. These promising results suggest that APN imaging can be expanded to detect and monitor other diseases that are associated with angiogenesis.
Topics: Animals; CD13 Antigens; Humans; Molecular Imaging; Neoplasms; Neovascularization, Pathologic
PubMed: 30046296
DOI: 10.1155/2018/5315172 -
Seminars in Nuclear Medicine Jul 2020Molecular imaging with positron emission tomography (PET) and single-photon emission computed tomography (SPECT) serves numerous applications in clinical cardiology and... (Review)
Review
Molecular imaging with positron emission tomography (PET) and single-photon emission computed tomography (SPECT) serves numerous applications in clinical cardiology and research. Similar to other medical imaging technologies, this area has undergone and continues to experience rapid changes resulting from technological and medical advances. These have immediate impacts on diagnosis, treatment planning, and patient care, as well as supplying innovative tools for fundamental and translational research. A broad shift toward hybrid PET systems and incorporation of advanced computational tools has been accompanied by mechanism-specific, targeted radiopharmaceuticals that seek to address long-standing limitations in cardiac imaging. While this review addresses some of the still-emerging clinical uses of established radiopharmaceuticals, it too highlights newer imaging probes, applications, and imaging techniques and instrumentation on the horizon. We highlight molecular imaging advances in inflammatory and infiltrative myocardial conditions, heart metabolism, vascular and valvular diseases, neurohormonal dysregulation, and transformational technical advances such as the rise of artificial intelligence and theranostic approaches to cardiovascular disease.
Topics: Cardiovascular Diseases; Heart; Humans; Molecular Imaging
PubMed: 32540033
DOI: 10.1053/j.semnuclmed.2020.02.005 -
Contrast Media & Molecular Imaging 2022In recent years, imaging technology has made rapid progress to improve the sensitivity of tumor diagnostic. With the development of genetic engineering and synthetic... (Review)
Review
In recent years, imaging technology has made rapid progress to improve the sensitivity of tumor diagnostic. With the development of genetic engineering and synthetic biology, various genetically encoded molecular imaging probes have also been extensively developed. As a biomedical imaging method with excellent detectable sensitivity and spatial resolution, genetically encoded molecular imaging has great application potential in the visualization of cellular and molecular functions during tumor development. Compared to chemosynthetic dyes and nanoparticles with an imaging function, genetically encoded molecular imaging probes can more easily label specific cells or proteins of interest in tumor tissues and have higher stability and tissue contrast Therefore, genetically encoded molecular imaging probes have attracted increasing attention from researchers in engineering and biomedicine. In this review, we aimed to introduce the genetically encoded molecular imaging probes and further explained their applications in tumor imaging.
Topics: Humans; Molecular Imaging; Molecular Probes; Nanoparticles; Neoplasms
PubMed: 36101803
DOI: 10.1155/2022/5473244 -
Trends in Molecular Medicine Apr 2021The rapidly developing field of molecular medical imaging focuses on specific visualization of (patho)physiological processes through the application of imaging agents... (Review)
Review
The rapidly developing field of molecular medical imaging focuses on specific visualization of (patho)physiological processes through the application of imaging agents (IAs) in multiple clinical modalities. Although our understanding of the principles underlying efficient IAs design has increased tremendously, many IAs still show poor in vivo imaging performance because of low binding affinity and/or specificity. These limitations can be addressed by taking advantage of multivalency, in which multiple copies of a ligand are employed to strengthen the interaction. We critically address specific challenges associated with the application of multivalent compounds in molecular imaging, and we give directions for a stepwise approach to the design of multivalent imaging probes to improve their target binding and pharmacokinetics (PK) for improved diagnostic potential.
Topics: Antibody Affinity; Binding Sites; Fluorescent Dyes; Molecular Imaging
PubMed: 33436332
DOI: 10.1016/j.molmed.2020.12.006 -
Drug Discovery Today Jan 2017Tremendous breakthroughs are being made in cancer drug discovery and development. However, such breakthroughs come at a high financial cost. At a time when there is... (Review)
Review
Tremendous breakthroughs are being made in cancer drug discovery and development. However, such breakthroughs come at a high financial cost. At a time when there is increasing pressure on drug pricing, in part because of increased life expectancy, it is more important than ever to drive new therapeutics towards patients as efficiently as possible. In this review we discuss the applications of molecular imaging in oncology drug development, with a focus on its ability to enable better early decision making, to increase efficiency and thereby to lower costs.
Topics: Antineoplastic Agents; Cost-Benefit Analysis; Drug Costs; Drug Discovery; Humans; Molecular Imaging; Tissue Distribution
PubMed: 27693713
DOI: 10.1016/j.drudis.2016.09.020 -
Bioconjugate Chemistry Feb 2020Gold nanoparticles (AuNP) have been extensively developed as contrast agents, theranostic platforms, and probes for molecular imaging. This popularity has yielded a... (Review)
Review
Gold nanoparticles (AuNP) have been extensively developed as contrast agents, theranostic platforms, and probes for molecular imaging. This popularity has yielded a large number of AuNP designs that vary in size, shape, surface functionalization, and assembly, to match very closely the requirements for various imaging applications. Hence, AuNP based probes for molecular imaging allow the use of computed tomography (CT), fluorescence, and other forms of optical imaging, photoacoustic imaging (PAI), and magnetic resonance imaging (MRI), and other newer techniques. The unique physicochemical properties, biocompatibility, and highly developed chemistry of AuNP have facilitated breakthroughs in molecular imaging that allow the detection and imaging of physiological processes with high sensitivity and spatial resolution. In this Review, we summarize the recent advances in molecular imaging achieved using novel AuNP structures, cell tracking using AuNP, targeted AuNP for cancer imaging, and activatable AuNP probes. Finally, the perspectives and current limitations for the clinical translation of AuNP based probes are discussed.
Topics: Animals; Cell Tracking; Gold; Humans; Magnetic Resonance Imaging; Metal Nanoparticles; Molecular Imaging; Optical Imaging; Photoacoustic Techniques; Tomography, X-Ray Computed
PubMed: 31682405
DOI: 10.1021/acs.bioconjchem.9b00669