51
|
Bar-Shir A, Liang Y, Chan KWY, Gilad AA, Bulte JWM. Supercharged green fluorescent proteins as bimodal reporter genes for CEST MRI and optical imaging. Chem Commun (Camb) 2015; 51:4869-71. [PMID: 25697683 DOI: 10.1039/c4cc10195b] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Superpositively charged mutants of green fluorescent protein (GFP) demonstrated a dramatically improved chemical exchange saturation transfer (CEST) MRI contrast compared to their wild type counterparts. The mutants +36 GFP and +48 GFP were successfully expressed in mammalian cells and retained part of their fluorescence, making them a new potential bimodal reporter gene.
Collapse
Affiliation(s)
- Amnon Bar-Shir
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | | | | | | |
Collapse
|
52
|
Andrzejewska A, Nowakowski A, Janowski M, Bulte JWM, Gilad AA, Walczak P, Lukomska B. Pre- and postmortem imaging of transplanted cells. Int J Nanomedicine 2015; 10:5543-59. [PMID: 26366076 PMCID: PMC4562754 DOI: 10.2147/ijn.s83557] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Therapeutic interventions based on the transplantation of stem and progenitor cells have garnered increasing interest. This interest is fueled by successful preclinical studies for indications in many diseases, including the cardiovascular, central nervous, and musculoskeletal system. Further progress in this field is contingent upon access to techniques that facilitate an unambiguous identification and characterization of grafted cells. Such methods are invaluable for optimization of cell delivery, improvement of cell survival, and assessment of the functional integration of grafted cells. Following is a focused overview of the currently available cell detection and tracking methodologies that covers the entire spectrum from pre- to postmortem cell identification.
Collapse
Affiliation(s)
- Anna Andrzejewska
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Adam Nowakowski
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Miroslaw Janowski
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
- Department of Neurosurgery, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
- RusselI H Morgan Department of Radiology and Radiological Science, Division of Magnetic Resonance Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jeff WM Bulte
- RusselI H Morgan Department of Radiology and Radiological Science, Division of Magnetic Resonance Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical & Biomolecular Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Assaf A Gilad
- RusselI H Morgan Department of Radiology and Radiological Science, Division of Magnetic Resonance Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Piotr Walczak
- RusselI H Morgan Department of Radiology and Radiological Science, Division of Magnetic Resonance Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Radiology, Faculty of Medical Sciences, University of Warmia and Mazury, Olsztyn, Poland
| | - Barbara Lukomska
- NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
53
|
Kuda-Wedagedara ANW, Allen MJ. Enhancing magnetic resonance imaging with contrast agents for ultra-high field strengths. Analyst 2015; 139:4401-10. [PMID: 25054827 DOI: 10.1039/c4an00990h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Contrast agents are diagnostic tools that often complement magnetic resonance imaging. At ultra-high field strengths (≥7 T), magnetic resonance imaging is capable of generating desirable high signal-to-noise ratios, but clinically available contrast agents are less effective at ultra-high field strengths relative to lower fields. This gap in effectiveness demands the development of contrast agents for ultra-high field strengths. In this minireview, we summarize contrast agents reported during the last three years that focused on ultra-high field strengths.
Collapse
|
54
|
Abstract
Molecular imaging plays an important role in the era of personalized medicine, especially with recent advances in magnetic resonance (MR) probes. While the first generation of these probes focused on maximizing contrast enhancement, a second generation of probes has been developed to improve the accumulation within specific tissues or pathologies, and the newest generation of agents is also designed to report on changes in physiological status and has been termed "smart" agents. This represents a paradigm switch from the previously commercialized gadolinium and iron oxide probes to probes with new capabilities, and leads to new challenges as scanner hardware needs to be adapted for detecting these probes. In this chapter, we highlight the unique features for all five different categories of MR probes, including the emerging chemical exchange saturation transfer, (19)F, and hyperpolarized probes, and describe the key physical properties and features motivating their design. As part of this comparison, the strengths and weaknesses of each category are discussed.
Collapse
Affiliation(s)
- Michael T McMahon
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA; The Russell H. Morgan Department of Radiology and Radiological Sciences, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
| | - Kannie W Y Chan
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA; The Russell H. Morgan Department of Radiology and Radiological Sciences, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
55
|
Bar-Shir A, Bulte JWM, Gilad AA. Molecular engineering of nonmetallic biosensors for CEST MRI. ACS Chem Biol 2015; 10:1160-70. [PMID: 25730583 PMCID: PMC11329289 DOI: 10.1021/cb500923v] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recent advancements in molecular and synthetic biology, combined with synthetic chemistry and biotechnology, have opened up new opportunities to engineer novel platforms that can monitor complex biological processes with various noninvasive imaging modalities. After decades of using gadolinium- or iron-based metallic sensors for MRI, the recently developed chemical exchange saturation transfer (CEST) contrast mechanism has created an opportunity for rational design, in silico, of nonmetallic biosensors for MRI. These biomolecules are either naturally occurring compounds (amino acids, sugars, nucleosides, native proteins) or can be artificially engineered (synthetic probes or recombinant proteins). They can be administered either as exogenous agents or can be genetically (over)expressed. Moreover, they can be precisely engineered to achieve the desired biochemical properties for fine tuning optimized imaging schemes. The availability of these agents marks the dawn of a new scientific era for molecular and cellular MRI.
Collapse
Affiliation(s)
- Amnon Bar-Shir
- †Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
- ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Jeff W M Bulte
- †Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
- ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- §F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21205, United States
- ∥Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- #Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
| | - Assaf A Gilad
- †Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
- ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- §F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21205, United States
| |
Collapse
|
56
|
Minn I, Bar-Shir A, Yarlagadda K, Bulte JWM, Fisher PB, Wang H, Gilad AA, Pomper MG. Tumor-specific expression and detection of a CEST reporter gene. Magn Reson Med 2015; 74:544-9. [PMID: 25919119 DOI: 10.1002/mrm.25748] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 03/25/2015] [Accepted: 04/02/2015] [Indexed: 12/19/2022]
Abstract
PURPOSE To develop an imaging tool that enables the detection of malignant tissue with enhanced specificity using the exquisite spatial resolution of MRI. METHODS Two mammalian gene expression vectors were created for the expression of the lysine-rich protein (LRP) under the control of the cytomegalovirus (CMV) promoter and the progression elevated gene-3 promoter (PEG-3 promoter) for constitutive and tumor-specific expression of LRP, respectively. Using those vectors, stable cell lines of rat 9L glioma, 9L(CMV-LRP) and 9L(PEG-LRP) , were established and tested for CEST contrast in vitro and in vivo. RESULTS 9L(PEG-LRP) cells showed increased CEST contrast compared with 9L cells in vitro. Both 9L(CMV-LRP) and 9L(PEG-LRP) cells were capable of generating tumors in the brains of mice, with a similar growth rate to tumors derived from wild-type 9L cells. An increase in CEST contrast was clearly visible in tumors derived from both 9L(CMV-LRP) and 9L(PEG-LRP) cells at 3.4 ppm. CONCLUSION The PEG-3 promoter:LRP system can be used as a cancer-specific, molecular-genetic imaging reporter system in vivo. Because of the ubiquity of MR imaging in clinical practice, sensors of this class can be used to translate molecular-genetic imaging rapidly.
Collapse
Affiliation(s)
- Il Minn
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Amnon Bar-Shir
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Cellular Imaging Section, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Keerthi Yarlagadda
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jeff W M Bulte
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Cellular Imaging Section, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Paul B Fisher
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia, USA.,VCU Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, Virginia, USA.,VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Hao Wang
- Division of Biostatistics and Bioinformatics, The Johns Hopkins University, Baltimore, Maryland, USA
| | - Assaf A Gilad
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Cellular Imaging Section, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Martin G Pomper
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
57
|
Srivastava AK, Kadayakkara DK, Bar-Shir A, Gilad AA, McMahon MT, Bulte JWM. Advances in using MRI probes and sensors for in vivo cell tracking as applied to regenerative medicine. Dis Model Mech 2015; 8:323-36. [PMID: 26035841 PMCID: PMC4381332 DOI: 10.1242/dmm.018499] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The field of molecular and cellular imaging allows molecules and cells to be visualized in vivo non-invasively. It has uses not only as a research tool but in clinical settings as well, for example in monitoring cell-based regenerative therapies, in which cells are transplanted to replace degenerating or damaged tissues, or to restore a physiological function. The success of such cell-based therapies depends on several critical issues, including the route and accuracy of cell transplantation, the fate of cells after transplantation, and the interaction of engrafted cells with the host microenvironment. To assess these issues, it is necessary to monitor transplanted cells non-invasively in real-time. Magnetic resonance imaging (MRI) is a tool uniquely suited to this task, given its ability to image deep inside tissue with high temporal resolution and sensitivity. Extraordinary efforts have recently been made to improve cellular MRI as applied to regenerative medicine, by developing more advanced contrast agents for use as probes and sensors. These advances enable the non-invasive monitoring of cell fate and, more recently, that of the different cellular functions of living cells, such as their enzymatic activity and gene expression, as well as their time point of cell death. We present here a review of recent advancements in the development of these probes and sensors, and of their functioning, applications and limitations.
Collapse
Affiliation(s)
- Amit K Srivastava
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Deepak K Kadayakkara
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Amnon Bar-Shir
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Assaf A Gilad
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Michael T McMahon
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Jeff W M Bulte
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA. Department of Chemical & Biomolecular Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
58
|
Oskolkov N, Bar-Shir A, Chan KW, Song X, van Zijl PC, Bulte JW, Gilad AA, McMahon MT. Biophysical Characterization of Human Protamine-1 as a Responsive CEST MR Contrast Agent. ACS Macro Lett 2015; 4:34-38. [PMID: 25642384 PMCID: PMC4307908 DOI: 10.1021/mz500681y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 12/15/2014] [Indexed: 11/28/2022]
Abstract
![]()
The protamines are a low-molecular-weight,
arginine-rich family
of nuclear proteins that protect chromosomal DNA in germ cells by
packing it densely using electrostatic interactions. Human protamine-1
(hPRM1) has been developed as a magnetic resonance imaging (MRI) chemical
exchange saturation transfer (CEST) reporter gene, based on a sequence
that is approximately 50% arginine, which has a side chain with rapidly
exchanging protons. In this study, we have synthesized hPRM1 and determined
how its CEST MRI contrast varies as a function of pH, phosphorylation
state, and upon noncovalent interaction with nucleic acids and heparin
(as antagonist). CEST contrast was found to be highly sensitive to
phosphorylation on serine residues, intra- and intermolecular disulfide
bridge formation, and the binding of negatively charged nucleotides
and heparin. In addition, the nucleotide binding constants (Keq) for the protamines were determined through
plotting the molar concentration of heparin versus CEST contrast and
compared between hPRM1 and salmon protamine. Taken together, these
findings are important for explaining the CEST contrast of existing
arginine-rich probes as well as serving as a guideline for designing
new genetic or synthetic probes.
Collapse
Affiliation(s)
- Nikita Oskolkov
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Amnon Bar-Shir
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Kannie W.Y. Chan
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Xiaolei Song
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Peter C.M. van Zijl
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Jeff W.M. Bulte
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Assaf A. Gilad
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Michael T. McMahon
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| |
Collapse
|
59
|
Abstract
Stem cell based-therapies are novel therapeutic strategies that hold key for developing new treatments for diseases conditions with very few or no cures. Although there has been an increase in the number of clinical trials involving stem cell-based therapies in the last few years, the long-term risks and benefits of these therapies are still unknown. Detailed in vivo studies are needed to monitor the fate of transplanted cells, including their distribution, differentiation, and longevity over time. Advancements in non-invasive cellular imaging techniques to track engrafted cells in real-time present a powerful tool for determining the efficacy of stem cell-based therapies. In this review, we describe the latest approaches to stem cell labeling and tracking using different imaging modalities.
Collapse
Affiliation(s)
- Amit K Srivastava
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, 217 Traylor Building, 720 Rutland Avenue, Baltimore, MD, 21205-1832, USA
| | | |
Collapse
|
60
|
Ekanger LA, Ali MM, Allen MJ. Oxidation-responsive Eu(2+/3+)-liposomal contrast agent for dual-mode magnetic resonance imaging. Chem Commun (Camb) 2014; 50:14835-8. [PMID: 25323054 PMCID: PMC4214894 DOI: 10.1039/c4cc07027e] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An oxidation-responsive contrast agent for magnetic resonance imaging was synthesized using Eu(2+) and liposomes. Positive contrast enhancement was observed with Eu(2+), and chemical exchange saturation transfer was observed before and after oxidation of Eu(2+). Orthogonal detection modes render the concentration of Eu inconsequential to molecular information provided through imaging.
Collapse
Affiliation(s)
- Levi A Ekanger
- Department of Chemistry, Wayne State University, 5101 Cass Ave., Detroit, MI 48202, USA.
| | | | | |
Collapse
|
61
|
Yang X, Yadav NN, Song X, Banerjee SR, Edelman H, Minn I, van Zijl PCM, Pomper MG, McMahon MT. Tuning phenols with Intra-Molecular bond Shifted HYdrogens (IM-SHY) as diaCEST MRI contrast agents. Chemistry 2014; 20:15824-32. [PMID: 25302635 PMCID: PMC4309366 DOI: 10.1002/chem.201403943] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Indexed: 01/31/2023]
Abstract
The optimal exchange properties for chemical exchange saturation transfer (CEST) contrast agents on 3 T clinical scanners were characterized using continuous wave saturation transfer, and it was demonstrated that the exchangeable protons in phenols can be tuned to reach these criteria through proper ring substitution. Systematic modification allows the chemical shift of the exchangeable protons to be positioned between 4.8 to 12 ppm from water and enables adjustment of the proton exchange rate to maximize CEST contrast at these shifts. In particular, 44 hydrogen-bonded phenols are investigated for their potential as CEST MRI contrast agents and the stereoelectronic effects on their CEST properties are summarized. Furthermore, a pair of compounds, 2,5-dihydroxyterephthalic acid and 4,6-dihydroxyisophthalic acid, were identified which produce the highest sensitivity through incorporating two exchangeable protons per ring.
Collapse
Affiliation(s)
- Xing Yang
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
| | - Nirbhay N. Yadav
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway Ave. Baltimore, MD 21287 (USA)
| | - Xiaolei Song
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway Ave. Baltimore, MD 21287 (USA)
| | - Sangeeta Ray Banerjee
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
| | - Hannah Edelman
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
| | - Il Minn
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
| | - Peter C. M. van Zijl
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway Ave. Baltimore, MD 21287 (USA)
| | - Martin G. Pomper
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
| | - Michael T. McMahon
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA)
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway Ave. Baltimore, MD 21287 (USA)
| |
Collapse
|
62
|
Longo DL, Sun PZ, Consolino L, Michelotti FC, Uggeri F, Aime S. A general MRI-CEST ratiometric approach for pH imaging: demonstration of in vivo pH mapping with iobitridol. J Am Chem Soc 2014; 136:14333-6. [PMID: 25238643 PMCID: PMC4210149 DOI: 10.1021/ja5059313] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Chemical exchange saturation transfer
(CEST) is a novel contrast
mechanism for magnetic resonance imaging (MRI). CEST MRI selectively
saturates exchangeable protons that are transferred to MRI-detectable
bulk water signal. MRI-CEST (pH)-responsive agents are probes able
to map pH in the microenvironment in which they distribute. To minimize
the confounding effects of contrast agent concentration, researchers
have developed ratiometric CEST imaging, which investigates contrast
agents containing multiple magnetically non-equivalent proton groups,
whose prototropic exchange have different pH responses. However, conventional
ratiometric CEST MRI imposes stringent requirements on the selection
of CEST contrasts agents. In this study, a novel ratiometric pH MRI
method based on the analysis of CEST effects under different radio
frequency irradiation power levels was developed. The proposed method
has been demonstrated using iobitridol, an X-ray contrast agent analog
of iopamidol but containing a single set of amide protons, both in vitro and in vivo.
Collapse
Affiliation(s)
- Dario L Longo
- Institute of Biostructures and Bioimages (CNR) c/o Molecular Biotechnology Center and §Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino , Torino 10126, Italy
| | | | | | | | | | | |
Collapse
|
63
|
Liu Z, Li Z. Molecular imaging in tracking tumor-specific cytotoxic T lymphocytes (CTLs). Am J Cancer Res 2014; 4:990-1001. [PMID: 25157278 PMCID: PMC4142291 DOI: 10.7150/thno.9268] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/30/2014] [Indexed: 01/15/2023] Open
Abstract
Despite the remarkable progress of adoptive T cell therapy in cancer treatment, there remains an urgent need for the noninvasive tracking of the transfused T cells in patients to determine their biodistribution, viability, and functionality. With emerging molecular imaging technologies and cell-labeling methods, noninvasive in vivo cell tracking is experiencing impressive progress toward revealing the mechanisms and functions of these cells in real time in preclinical and clinical studies. Such cell tracking methods have an important role in developing effective T cell therapeutic strategies and steering decision-making process in clinical trials. On the other hand, they could provide crucial information to accelerate the regulatory approval process on the T cell therapy. In this review, we revisit the advances in tracking the tumor-specific CTLs, highlighting the latest development in human studies and the key challenges.
Collapse
|
64
|
Song X, Yang X, Ray Banerjee S, Pomper MG, McMahon MT. Anthranilic acid analogs as diamagnetic CEST MRI contrast agents that feature an intramolecular-bond shifted hydrogen. CONTRAST MEDIA & MOLECULAR IMAGING 2014; 10:74-80. [PMID: 24771546 DOI: 10.1002/cmmi.1597] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 01/22/2014] [Accepted: 01/29/2014] [Indexed: 12/23/2022]
Abstract
Diamagnetic chemical exchange saturation transfer (diaCEST) agents are a new class of imaging agents, which have unique magnetic resonance (MR) properties similar to agents used for optical imaging. Here we present a series of anthranilic acid analogs as examples of diaCEST agents that feature an exchangeable proton shifted downfield, namely, an intramolecular-bond shifted hydrogen (IM-SHY), which produces significant and tunable contrast at frequencies of 4.8-9.3 ppm from water. Five analogs of N-sulfonyl anthranilic acids are all highly soluble and produced similar CEST contrast at ~6-8 ppm. We also discovered that flufenamic acid, a commercial nonsteroidal anti-inflammatory drug, displayed CEST contrast at 4.8 ppm. For these N-H IM-SHY agents, the contrast produced was insensitive to pH, making them complementary to existing diaCEST probes. This initial IM-SHY library includes the largest reported shifts for N-H protons on small organic diaCEST agents, and should find use as multifrequency MR agents for in vivo applications.
Collapse
Affiliation(s)
- Xiaolei Song
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | | | | | | | | |
Collapse
|
65
|
Bar-Shir A, Liu G, Chan KW, Oskolkov N, Song X, Yadav NN, Walczak P, McMahon MT, van Zijl PCM, Bulte JWM, Gilad AA. Human protamine-1 as an MRI reporter gene based on chemical exchange. ACS Chem Biol 2014; 9:134-8. [PMID: 24138139 DOI: 10.1021/cb400617q] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Genetically engineered reporters have revolutionized the understanding of many biological processes. MRI-based reporter genes can dramatically improve our ability to monitor dynamic gene expression and allow coregistration of subcellular genetic information with high-resolution anatomical images. We have developed a biocompatible MRI reporter gene based on a human gene, the human protamine-1 (hPRM1). The arginine-rich hPRM1 (47% arginine residues) generates high MRI contrast based on the chemical exchange saturation transfer (CEST) contrast mechanism. The 51 amino acid-long hPRM1 protein was fully synthesized using microwave-assisted technology, and the CEST characteristics of this protein were compared to other CEST-based contrast agents. Both bacterial and human cells were engineered to express an optimized hPRM1 gene and showed higher CEST contrast compared to controls. Live cells expressing the hPRM1 reporter gene, and embedded in three-dimensional culture, also generated higher CEST contrast compared to wild-type live cells.
Collapse
Affiliation(s)
- Amnon Bar-Shir
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
| | - Guanshu Liu
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| | - Kannie W.Y. Chan
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| | - Nikita Oskolkov
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| | - Xiaolei Song
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| | - Nirbhay N. Yadav
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| | - Piotr Walczak
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
| | - Michael T. McMahon
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| | - Peter C. M. van Zijl
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| | - Jeff W. M. Bulte
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
- Department
of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- Department of Chemical & Biomolecular Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
| | - Assaf A. Gilad
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, United States
- F. M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21231, United States
| |
Collapse
|
66
|
Abstract
Research into cell therapy based cardiac repair and regeneration has experienced explosive growth over the last decade, however further progress is hindered by an inability to serially and non-invasively image cell survival and fate decisions following implantation. Recent advances in magnetic resonance imaging (MRI) reporter gene techniques have enabled in vivo imaging of cell survival, proliferation, migration, and differentiation, however this has mostly been performed in stationary tissues. A small series of recent studies has examined the possibility of using MRI reporter genes to track the survival of cells injected into the heart following myocardial infarction. In this review, we seek to frame the emerging field of MRI reporter gene based cardiac cell tracking within the larger framework of the needs of cardiac regeneration therapy and the more established field of MRI cell tracking. While initial studies have demonstrated a promising ability to track the viability and proliferation of cells used for cell therapy, the ultimate goal of MR reporter gene imaging in the heart remains the ability to simultaneously correlate cell fate decisions with additional measures of structural and functional recovery.
Collapse
Affiliation(s)
- Moriel Vandsburger
- Department of Physiology, University of Kentucky, Lexington, KY USA
- Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone, BBSRB 355, Lexington, KY 40536 USA
| |
Collapse
|
67
|
Zaiss M, Bachert P. Chemical exchange saturation transfer (CEST) and MRZ-spectroscopyin vivo: a review of theoretical approaches and methods. Phys Med Biol 2013; 58:R221-69. [DOI: 10.1088/0031-9155/58/22/r221] [Citation(s) in RCA: 216] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
68
|
Synthesis of a probe for monitoring HSV1-tk reporter gene expression using chemical exchange saturation transfer MRI. Nat Protoc 2013; 8:2380-91. [PMID: 24177294 DOI: 10.1038/nprot.2013.140] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In experiments involving transgenic animals or animals treated with transgenic cells, it is important to have a method to monitor the expression of the relevant genes longitudinally and noninvasively. An MRI-based reporter gene enables monitoring of gene expression in the deep tissues of living subjects. This information can be co-registered with detailed high-resolution anatomical and functional information. We describe here the synthesis of the reporter probe, 5-methyl-5,6-dihydrothymidine (5-MDHT), which can be used for imaging of the herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene expression in rodents by MRI. The protocol also includes data acquisition and data processing routines customized for chemical exchange saturation transfer (CEST) contrast mechanisms. The dihydropyrimidine 5-MDHT is synthesized through a catalytic hydrogenation of the 5,6-double bond of thymidine to yield 5,6-dihydrothymidine, which is methylated on the C-5 position of the resulting saturated pyrimidine ring. The synthesis of 5-MDHT can be completed within 5 d, and the compound is stable for more than 1 year.
Collapse
|
69
|
Abstract
The increasing complexity of in vivo imaging technologies, coupled with the development of cell therapies, has fuelled a revolution in immune cell tracking in vivo. Powerful magnetic resonance imaging (MRI) methods are now being developed that use iron oxide- and ¹⁹F-based probes. These MRI technologies can be used for image-guided immune cell delivery and for the visualization of immune cell homing and engraftment, inflammation, cell physiology and gene expression. MRI-based cell tracking is now also being applied to evaluate therapeutics that modulate endogenous immune cell recruitment and to monitor emerging cellular immunotherapies. These recent uses show that MRI has the potential to be developed in many applications to follow the fate of immune cells in vivo.
Collapse
|
70
|
Bar-Shir A, Gilad AA, Chan KWY, Liu G, van Zijl PCM, Bulte JWM, McMahon MT. Metal ion sensing using ion chemical exchange saturation transfer 19F magnetic resonance imaging. J Am Chem Soc 2013; 135:12164-7. [PMID: 23905693 DOI: 10.1021/ja403542g] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Although metal ions are involved in a myriad of biological processes, noninvasive detection of free metal ions in deep tissue remains a formidable challenge. We present an approach for specific sensing of the presence of Ca(2+) in which the amplification strategy of chemical exchange saturation transfer (CEST) is combined with the broad range of chemical shifts found in (19)F NMR spectroscopy to obtain magnetic resonance images of Ca(2+). We exploited the chemical shift change (Δω) of (19)F upon binding of Ca(2+) to the 5,5'-difluoro derivative of 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (5F-BAPTA) by radiofrequency labeling at the Ca(2+)-bound (19)F frequency and detection of the label transfer to the Ca(2+)-free (19)F frequency. Through the substrate binding kinetics we were able to amplify the signal of Ca(2+) onto free 5F-BAPTA and thus indirectly detect low Ca(2+) concentrations with high sensitivity.
Collapse
Affiliation(s)
- Amnon Bar-Shir
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | | | | | | | | | | | | |
Collapse
|
71
|
Yang X, Song X, Li Y, Liu G, Banerjee SR, Pomper MG, McMahon MT. Salicylic acid and analogues as diaCEST MRI contrast agents with highly shifted exchangeable proton frequencies. Angew Chem Int Ed Engl 2013; 52:8116-9. [PMID: 23794432 PMCID: PMC3819166 DOI: 10.1002/anie.201302764] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/27/2013] [Indexed: 12/27/2022]
Affiliation(s)
- Xing Yang
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, Maryland 21287 (USA)
| | - Xiaolei Song
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, Maryland 21287 (USA)
| | - Yuguo Li
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, Maryland 21287 (USA)
| | - Guanshu Liu
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, Maryland 21287 (USA); F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway Ave., Baltimore, Maryland 21287 (USA)
| | - Sangeeta Ray Banerjee
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, Maryland 21287 (USA)
| | - Martin G. Pomper
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, Maryland 21287 (USA)
| | - Michael T. McMahon
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, Maryland 21287 (USA); F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway Ave., Baltimore, Maryland 21287 (USA)
| |
Collapse
|
72
|
Yang X, Song X, Li Y, Liu G, Ray Banerjee S, Pomper MG, McMahon MT. Salicylic Acid and Analogues as diaCEST MRI Contrast Agents with Highly Shifted Exchangeable Proton Frequencies. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201302764] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|