1
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Yan J, Yin M, Foster FS, Démoré CEM. Tumor Contrast Imaging with Gas Vesicles by Circumventing the Reticuloendothelial System. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:359-368. [PMID: 31708270 DOI: 10.1016/j.ultrasmedbio.2019.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/07/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Gas vesicles (GVs) are nanosized structures (45-800 nm) and have been reported to produce non-linear contrast signals, making them an attractive agent for molecular targeting of tumors. One barrier to their use for pre-clinical oncology studies is rapid uptake into the reticuloendothelial system (RES) and consequent rapid decrease in contrast signal after infusion ends and low signal on reperfusion after a bubble burst sequence. The purpose of this study was to examine suppression of the RES and surface modification of GVs to prolong contrast circulation in tumors for ultrasound imaging. Ultrasound imaging to measure dynamics of contrast signal intensity in tumor models was carried out using a 21-MHz high-frequency array transducer with the Vevo 2100 ultrasound system. The non-linear contrast signal from intravenously injected GVs compared with peak enhancement was measured during contrast wash-out and on reperfusion after a contrast burst sequence. Disrupting the RES by saturating the macrophage population or chemically inhibiting the Kupffer cell population with gadolinium or Intralipid preserves 62%-88% of GVs' contrast enhancement relative to peak during the wash-out phase and 32%-56% on reperfusion compared with 38% and 14%, respectively, for no disruption of the RES, indicating longer circulation of GVs in the tumor. Additionally, coating the GVs with 2-, 5- or 10-kDa polyethylene glycol (PEG) chains resulted in >70% contrast signal retention in the tumors during wash-out and, for 5- or 10-kDa PEG chains, a return to >45% of peak contrast signal on reperfusion. These findings indicate that GVs can be used as a contrast agent for tumor imaging and that disruption of the RES improved recirculation and maintained contrast enhancement caused by GVs in the tumors.
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Affiliation(s)
- Judy Yan
- Sunnybrook Research Institute, Toronto, Ontario, Canada.
| | - Melissa Yin
- FUJIFILM VisualSonics Inc., Toronto, Ontario, Canada
| | - F Stuart Foster
- Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Christine E M Démoré
- Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
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2
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Gabrielson K, Maronpot R, Monette S, Mlynarczyk C, Ramot Y, Nyska A, Sysa-Shah P. In Vivo Imaging With Confirmation by Histopathology for Increased Rigor and Reproducibility in Translational Research: A Review of Examples, Options, and Resources. ILAR J 2018; 59:80-98. [PMID: 30541081 PMCID: PMC6645176 DOI: 10.1093/ilar/ily010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 07/18/2018] [Indexed: 12/13/2022] Open
Abstract
Preclinical noninvasive imaging can be an indispensable tool for studying animal models of disease. In vivo imaging to assess anatomical, functional, and molecular features requires verification by a comparison to the macroscopic and microscopic morphological features, since all noninvasive in vivo imaging methods have much lower resolution than standard histopathology. Comprehensive pathological evaluation of the animal model is underutilized; yet, many institutions have veterinary or human pathologists with necessary comparative pathology expertise. By performing a rigorous comparison to gross or histopathology for image interpretation, these trained individuals can assist scientists with the development of the animal model, experimental design, and evaluation of the in vivo imaging data. These imaging and pathology corroboration studies undoubtedly increase scientific rigor and reproducibility in descriptive and hypothesis-driven research. A review of case examples including ultrasound, nuclear, optical, and MRI is provided to illustrate how a wide range of imaging modalities data can be confirmed by gross or microscopic pathology. This image confirmation and authentication will improve characterization of the model and may contribute to decreasing costs and number of animals used and to more rapid translation from preclinical animal model to the clinic.
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Affiliation(s)
- Kathleen Gabrielson
- Departments of Molecular and Comparative Pathology and Pathology School of Medicine, Environmental Health Engineering Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | | | - Sébastien Monette
- Laboratory of Comparative Pathology, Memorial Sloan Kettering Cancer Center, The Rockefeller University, Weill Cornell Medicine, New York, New York
| | - Coraline Mlynarczyk
- Department of Medicine, Division of Hematology & Medical Oncology and the Meyer Cancer Center, Weill Cornell Medicine, New York, New York
| | - Yuval Ramot
- Department of Dermatology, Hadassah—Hebrew University Medical Center, Kiryat Hadassah, Jerusalem, Israel
| | - Abraham Nyska
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel and Toxicologic Pathology, Timrat, Israel
| | - Polina Sysa-Shah
- Department of Radiology, Miller Research Building Molecular Imaging Service Center, Johns Hopkins University, Baltimore, Maryland
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3
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Zhang C, Wang N, Tan HY, Guo W, Li S, Feng Y. Targeting VEGF/VEGFRs Pathway in the Antiangiogenic Treatment of Human Cancers by Traditional Chinese Medicine. Integr Cancer Ther 2018; 17:582-601. [PMID: 29807443 PMCID: PMC6142106 DOI: 10.1177/1534735418775828] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Bearing in mind the doctrine of tumor angiogenesis hypothesized by Folkman
several decades ago, the fundamental strategy for alleviating numerous cancer
indications may be the strengthening application of notable antiangiogenic
therapies to inhibit metastasis-related tumor growth. Under physiological
conditions, vascular sprouting is a relatively infrequent event unless when
specifically stimulated by pathogenic factors that contribute to the
accumulation of angiogenic activators such as the vascular endothelial growth
factor (VEGF) family and basic fibroblast growth factor (bFGF). Since VEGFs have
been identified as the principal cytokine to initiate angiogenesis in tumor
growth, synthetic VEGF-targeting medicines containing bevacizumab and sorafenib
have been extensively used, but prominent side effects have concomitantly
emerged. Traditional Chinese medicines (TCM)–derived agents with distinctive
safety profiles have shown their multitarget curative potential by impairing
angiogenic stimulatory signaling pathways directly or eliciting synergistically
therapeutic effects with anti-angiogenic drugs mainly targeting VEGF-dependent
pathways. This review aims to summarize (a) the up-to-date
understanding of the role of VEGF/VEGFR in correlation with proangiogenic
mechanisms in various tissues and cells; (b) the elaboration of
antitumor angiogenesis mechanisms of 4 representative TCMs, including
Salvia miltiorrhiza, Curcuma longa, ginsenosides, and
Scutellaria baicalensis; and (c)
circumstantial clarification of TCM-driven therapeutic actions of suppressing
tumor angiogenesis by targeting VEGF/VEGFRs pathway in recent years, based on
network pharmacology.
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Affiliation(s)
- Cheng Zhang
- 1 The University of Hong Kong, Hong Kong SAR
| | - Ning Wang
- 1 The University of Hong Kong, Hong Kong SAR
| | - Hor-Yue Tan
- 1 The University of Hong Kong, Hong Kong SAR
| | - Wei Guo
- 1 The University of Hong Kong, Hong Kong SAR
| | - Sha Li
- 1 The University of Hong Kong, Hong Kong SAR
| | - Yibin Feng
- 1 The University of Hong Kong, Hong Kong SAR
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4
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Wischhusen J, Padilla F. Microbubble Enzyme-Linked Immunosorbent Assay for the Detection of Targeted Microbubbles in in Vitro Static Binding Assays. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:1506-1519. [PMID: 28450034 DOI: 10.1016/j.ultrasmedbio.2017.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/28/2017] [Accepted: 03/07/2017] [Indexed: 06/07/2023]
Abstract
Targeted microbubbles (MBs) are ultrasound contrast agents that are functionalized with a ligand for ultrasound molecular imaging of endothelial markers. Novel targeted MBs are characterized in vitro by incubation in protein-coated wells, followed by binding quantification by microscopy or ultrasound imaging. Both methods provide operator-dependent results: Between 3 and 20 fields of view from a heterogeneous sample are typically selected for analysis by microscopy, and in ultrasound imaging, different acoustic settings affect signal intensities. This study proposes a new method to reproducibly quantify MB binding based on enzyme-linked immunosorbent assay (ELISA), in which bound MBs are revealed with an enzyme-linked antibody. MB-ELISA was adapted to in vitro static binding assays, incubating the MBs in inverted position or by agitation, and compared with microscopy. The specificity and sensitivity of MB-ELISA enable the reliable quantification of MB binding in a rapid, high-throughput and whole-well analysis, facilitating the characterization of new targeted contrast agents.
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Affiliation(s)
| | - Frederic Padilla
- INSERM, U1032, LabTAU, Lyon, France; Université de Lyon, Lyon, France.
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5
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Harpel K, Baker RD, Amirsolaimani B, Mehravar S, Vagner J, Matsunaga TO, Banerjee B, Kieu K. Imaging of targeted lipid microbubbles to detect cancer cells using third harmonic generation microscopy. BIOMEDICAL OPTICS EXPRESS 2016; 7:2849-60. [PMID: 27446711 PMCID: PMC4948635 DOI: 10.1364/boe.7.002849] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/17/2016] [Accepted: 06/17/2016] [Indexed: 05/19/2023]
Abstract
The use of receptor-targeted lipid microbubbles imaged by ultrasound is an innovative method of detecting and localizing disease. However, since ultrasound requires a medium between the transducer and the object being imaged, it is impractical to apply to an exposed surface in a surgical setting where sterile fields need be maintained and ultrasound gel may cause the bubbles to collapse. Multiphoton microscopy (MPM) is an emerging tool for accurate, label-free imaging of tissues and cells with high resolution and contrast. We have recently determined a novel application of MPM to be used for detecting targeted microbubble adherence to the upregulated plectin-receptor on pancreatic tumor cells. Specifically, the third-harmonic generation response can be used to detect bound microbubbles to various cell types presenting MPM as an alternative and useful imaging method. This is an interesting technique that can potentially be translated as a diagnostic tool for the early detection of cancer and inflammatory disorders.
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Affiliation(s)
- Kaitlin Harpel
- Department of Biomedical Engineering, University of Arizona, 1127 E. James E. Rogers Way, Tucson, Arizona, 85721, USA
- Department of Medical Imaging, College of Medicine, University of Arizona, 1609 N. Warren Ave., Tucson, Arizona, 85719, USA
| | - Robert Dawson Baker
- College of Optical Sciences, University of Arizona, 1603 E. University Blvd., Tucson, AZ, 85721, USA
| | - Babak Amirsolaimani
- College of Optical Sciences, University of Arizona, 1603 E. University Blvd., Tucson, AZ, 85721, USA
| | - Soroush Mehravar
- College of Optical Sciences, University of Arizona, 1603 E. University Blvd., Tucson, AZ, 85721, USA
| | - Josef Vagner
- Ligand Discovery Laboratory, BIO5 Institute, University of Arizona, 1657 E. Helen Street, Tucson, AZ, 85721, USA
| | - Terry O. Matsunaga
- Department of Biomedical Engineering, University of Arizona, 1127 E. James E. Rogers Way, Tucson, Arizona, 85721, USA
- Department of Medical Imaging, College of Medicine, University of Arizona, 1609 N. Warren Ave., Tucson, Arizona, 85719, USA
| | - Bhaskar Banerjee
- Department of Biomedical Engineering, University of Arizona, 1127 E. James E. Rogers Way, Tucson, Arizona, 85721, USA
- College of Optical Sciences, University of Arizona, 1603 E. University Blvd., Tucson, AZ, 85721, USA
- Department of Medicine, College of Medicine, University of Arizona, 1501 N. Campbell, Tucson, Arizona, 85724, USA
| | - Khanh Kieu
- College of Optical Sciences, University of Arizona, 1603 E. University Blvd., Tucson, AZ, 85721, USA
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6
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Shelton SE, Lindsey BD, Tsuruta JK, Foster FS, Dayton PA. Molecular Acoustic Angiography: A New Technique for High-resolution Superharmonic Ultrasound Molecular Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:769-81. [PMID: 26678155 PMCID: PMC5653972 DOI: 10.1016/j.ultrasmedbio.2015.10.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 10/14/2015] [Accepted: 10/18/2015] [Indexed: 05/09/2023]
Abstract
Ultrasound molecular imaging utilizes targeted microbubbles to bind to vascular targets such as integrins, selectins and other extracellular binding domains. After binding, these microbubbles are typically imaged using low pressures and multi-pulse imaging sequences. In this article, we present an alternative approach for molecular imaging using ultrasound that relies on superharmonic signals produced by microbubble contrast agents. Bound bubbles were insonified near resonance using a low frequency (4 MHz) element and superharmonic echoes were received at high frequencies (25-30 MHz). Although this approach was observed to produce declining image intensity during repeated imaging in both in vitro and in vivo experiments because of bubble destruction, the feasibility of superharmonic molecular imaging was demonstrated for transmit pressures, which are sufficiently high to induce shell disruption in bound microbubbles. This approach was validated using microbubbles targeted to the αvβ3 integrin in a rat fibrosarcoma model (n = 5) and combined with superharmonic images of free microbubbles to produce high-contrast, high-resolution 3-D volumes of both microvascular anatomy and molecular targeting. Image intensity over repeated scans and the effect of microbubble diameter were also assessed in vivo, indicating that larger microbubbles yield increased persistence in image intensity. Using ultrasound-based acoustic angiography images rather than conventional B-mode ultrasound to provide the underlying anatomic information facilitates anatomic localization of molecular markers. Quantitative analysis of relationships between microvasculature and targeting information indicated that most targeting occurred within 50 μm of a resolvable vessel (>100 μm diameter). The combined information provided by these scans may present new opportunities for analyzing relationships between microvascular anatomy and vascular targets, subject only to limitations of the current mechanically scanned system and microbubble persistence to repeated imaging at moderate mechanical indices.
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Affiliation(s)
- Sarah E Shelton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Brooks D Lindsey
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - James K Tsuruta
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - F Stuart Foster
- Department of Medical Biophysics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA; Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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7
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Bar-Zion AD, Tremblay-Darveau C, Yin M, Adam D, Foster FS. Denoising of Contrast-Enhanced Ultrasound Cine Sequences Based on a Multiplicative Model. IEEE Trans Biomed Eng 2015; 62:1969-80. [DOI: 10.1109/tbme.2015.2407835] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Oda Y, Suzuki R, Mori T, Takahashi H, Natsugari H, Omata D, Unga J, Uruga H, Sugii M, Kawakami S, Higuchi Y, Yamashita F, Hashida M, Maruyama K. Development of fluorous lipid-based nanobubbles for efficiently containing perfluoropropane. Int J Pharm 2015; 487:64-71. [PMID: 25841568 DOI: 10.1016/j.ijpharm.2015.03.073] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/24/2015] [Accepted: 03/30/2015] [Indexed: 12/21/2022]
Abstract
Nano-/microbubbles are expected not only to function as ultrasound contrast agents but also as ultrasound-triggered enhancers in gene and drug delivery. Notably, nanobubbles have the ability to pass through tumor vasculature and achieve passive tumor targeting. Thus, nanobubbles would be an attractive tool for use as ultrasound-mediated cancer theranostics. However, the amounts of gas carried by nanobubbles are generally lower than those carried by microbubbles because nanobubbles have inherently smaller volumes. In order to reduce the injection volume and to increase echogenicity, it is important to develop nanobubbles with higher gas content. In this study, we prepared 5 kinds of fluoro-lipids and used these reagents as surfactants to generate "Bubble liposomes", that is, liposomes that encapsulate nanobubbles such that the lipids serve as stabilizers between the fluorous gas and water phases. Bubble liposome containing 1-stearoyl-2-(18,18-difluoro)stearoyl-sn-glycero-3-phosphocholine carried 2-fold higher amounts of C3F8 compared to unmodified Bubble liposome. The modified Bubble liposome also exhibited increased echogenicity by ultrasonography. These results demonstrated that the inclusion of fluoro-lipid is a promising tool for generating nanobubbles with increased efficiency of fluorous gas carrier.
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Affiliation(s)
- Yusuke Oda
- Laboratory of Drug and Gene Delivery System, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Ryo Suzuki
- Laboratory of Drug and Gene Delivery System, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Tatsuya Mori
- Laboratory of Organic Chemistry, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Hideyo Takahashi
- Laboratory of Organic Chemistry, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Hideaki Natsugari
- Laboratory of Organic Chemistry, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Daiki Omata
- Laboratory of Drug and Gene Delivery System, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Johan Unga
- Laboratory of Drug and Gene Delivery System, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Hitoshi Uruga
- Laboratory of Drug and Gene Delivery System, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Mutsumi Sugii
- Laboratory of Drug and Gene Delivery System, Faculty of Pharma-Sciences, Teikyo University, Japan
| | - Shigeru Kawakami
- Analytical Research for Pharmacoinformatics, Graduate School of Biomedical Sciences Medical and Dental Sciences, Nagasaki University, Japan
| | - Yuriko Higuchi
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
| | - Fumiyoshi Yamashita
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
| | - Mitsuru Hashida
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
| | - Kazuo Maruyama
- Laboratory of Drug and Gene Delivery System, Faculty of Pharma-Sciences, Teikyo University, Japan.
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9
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Denbeigh JM, Nixon BA, Puri MC, Foster FS. Contrast imaging in mouse embryos using high-frequency ultrasound. J Vis Exp 2015:52520. [PMID: 25867243 PMCID: PMC4401211 DOI: 10.3791/52520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Ultrasound contrast-enhanced imaging can convey essential quantitative information regarding tissue vascularity and perfusion and, in targeted applications, facilitate the detection and measure of vascular biomarkers at the molecular level. Within the mouse embryo, this noninvasive technique may be used to uncover basic mechanisms underlying vascular development in the early mouse circulatory system and in genetic models of cardiovascular disease. The mouse embryo also presents as an excellent model for studying the adhesion of microbubbles to angiogenic targets (including vascular endothelial growth factor receptor 2 (VEGFR2) or αvβ3) and for assessing the quantitative nature of molecular ultrasound. We therefore developed a method to introduce ultrasound contrast agents into the vasculature of living, isolated embryos. This allows freedom in terms of injection control and positioning, reproducibility of the imaging plane without obstruction and motion, and simplified image analysis and quantification. Late gestational stage (embryonic day (E)16.6 and E17.5) murine embryos were isolated from the uterus, gently exteriorized from the yolk sac and microbubble contrast agents were injected into veins accessible on the chorionic surface of the placental disc. Nonlinear contrast ultrasound imaging was then employed to collect a number of basic perfusion parameters (peak enhancement, wash-in rate and time to peak) and quantify targeted microbubble binding in an endoglin mouse model. We show the successful circulation of microbubbles within living embryos and the utility of this approach in characterizing embryonic vasculature and microbubble behavior.
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Affiliation(s)
- Janet M Denbeigh
- Department of Medical Biophysics, University of Toronto; Sunnybrook Research Institute;
| | - Brian A Nixon
- Department of Medical Biophysics, University of Toronto; Sunnybrook Research Institute
| | - Mira C Puri
- Department of Medical Biophysics, University of Toronto; Sunnybrook Research Institute; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto
| | - F Stuart Foster
- Department of Medical Biophysics, University of Toronto; Sunnybrook Research Institute
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10
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Liu H, Chen Y, Yan F, Han X, Wu J, Liu X, Zheng H. Ultrasound molecular imaging of vascular endothelial growth factor receptor 2 expression for endometrial receptivity evaluation. Theranostics 2015; 5:206-17. [PMID: 25553109 PMCID: PMC4279005 DOI: 10.7150/thno.9847] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Accepted: 10/05/2014] [Indexed: 12/17/2022] Open
Abstract
Purpose: Ultrasound (US) molecular imaging by examining the expression of vascular endothelial growth factor receptor 2 (VEGFR2) on uterus vascular endothelium was applied to evaluate the endometrial receptivity. Methods: VEGFR2-targeted ultrasound contrast agents (UCA) and the control UCA (without VEGFR2) were prepared and characterized. Adhesion experiment in vitro was performed with mouse microvascular endothelial cells (bEnd.3) and the ratio of the number of UCA to that of cells at the same field was compared. In vivo study, randomized boluses of targeted or control UCA were injected into the animals of non-pregnancy (D0), pregnancy on day 2 (D2) and day 4 (D4), respectively. Sonograms were acquired by an ultrasound equipment with a 40-MHz high-frequency transducer (Vevo 2100; VisualSonics, Toronto, Canada). The ultrasonic imaging signals were quantified as the video intensity amplitudes generated by the attachment of VEGFR2-targeted UCA. Immunoblotting and immunofluorescence assays were used for confirmation of VEGFR2 expression. Results: Our results showed that VEGFR2-targeted UCA could bind to bEnd.3 cells with significantly higher affinity than the control UCA (9.8 ± 1.0 bubbles/cell versus 0.7 ± 0.3 bubbles/cell, P < 0.01) in vitro. The mean video intensity from the US backscattering of the retained VEGFR2-targeted UCA was significantly higher than that of the control UCA in D2 and D4 mice (D2, 10.5 ± 2.5 dB versus 1.5 ± 1.1 dB, P < 0.01; D4, 15.7 ± 4.0 dB versus 1.5 ± 1.2 dB, P < 0.01), but not significantly different in D0 mice (1.0 ± 0.8 dB versus 0.9 ± 0.6 dB, P > 0.05). Moreover, D4 mice showed the highest video intensity amplitude, indicating the highest VEGFR2 expression when compared with D2 and D0 mice (P < 0.01). This was further confirmed by our immunoblotting and immunofluorescence experiments. Conclusion: Ultrasound molecular imaging with VEGFR2-targeted UCA may be used for noninvasive evaluation of endometrial receptivity in murine models.
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11
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Tian N, Qu YW, Liu HF. Targeted ultrasound microbubble contrast agents for enhanced tumor imaging. Shijie Huaren Xiaohua Zazhi 2014; 22:5100-5105. [DOI: 10.11569/wcjd.v22.i33.5100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the field of medical ultrasound, ultrasound microbubbles are a new class of ultrasound contrast agents. Ultrasound microbubbles can be divided into two types: ordinary and targeted microbubbles. Ordinary microbubbles have been widely used in clinical practice. Targeted microbubbles are a special class of contrast agents and can be divided into micron- and nano-scale targeted microbubbles according to particle size. The former cannot pass through the endothelial gap due to the larger particle size, while the latter can pass through the vascular endothelium and allows for imaging of the extravascular tissues. Ultrasound combined with targeted microbubbles in enhancing tumor imaging shows greater advantages and has become an important topic of research; however, its unknown toxicity limits its wider application. In addition, ultrasound parameters still need to be optimized.
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12
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Denbeigh JM, Nixon BA, Lee JJY, Jerkic M, Marsden PA, Letarte M, Puri MC, Foster FS. Contrast-enhanced molecular ultrasound differentiates endoglin genotypes in mouse embryos. Angiogenesis 2014; 18:69-81. [PMID: 25298070 DOI: 10.1007/s10456-014-9447-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 09/26/2014] [Indexed: 12/31/2022]
Abstract
Targeted ultrasound contrast imaging has the potential to become a reliable molecular imaging tool. A better understanding of the quantitative aspects of molecular ultrasound technology could facilitate the translation of this technique to the clinic for the purposes of assessing vascular pathology and detecting individual response to treatment. The objective of this study was to evaluate whether targeted ultrasound contrast-enhanced imaging can provide a quantitative measure of endogenous biomarkers. Endoglin, an endothelial biomarker involved in the processes of development, vascular homeostasis, and altered in diseases, including hereditary hemorrhagic telangiectasia type 1 and tumor angiogenesis, was the selected target. We used a parallel plate perfusion chamber in which endoglin-targeted (MBE), rat isotype IgG2 control and untargeted microbubbles were perfused across endoglin wild-type (Eng+/+), heterozygous (Eng+/-) and null (Eng-/-) embryonic mouse endothelial cells and their adhesion quantified. Microbubble binding was also assessed in late-gestation, isolated living transgenic Eng+/- and Eng+/+ embryos. Nonlinear contrast-specific ultrasound imaging performed at 21 MHz was used to collect contrast mean power ratios for all bubble types. Statistically significant differences in microbubble binding were found across genotypes for both in vitro (p<0.05) and embryonic studies (p<0.001); MBE binding was approximately twofold higher in Eng+/+ cells and embryos compared with their Eng+/- counterparts. These results suggest that molecular ultrasound is capable of reliably differentiating between molecular genotypes and relating receptor densities to quantifiable molecular ultrasound levels.
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Affiliation(s)
- J M Denbeigh
- Department of Medical Biophysics, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, S640, Toronto, Ontario, M4N 3M5, Canada,
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