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Asfour H, Otridge J, Thomasian R, Larson C, Sarvazyan N. Autofluorescence properties of balloon polymers used in medical applications. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200216R. [PMID: 33084257 PMCID: PMC7575097 DOI: 10.1117/1.jbo.25.10.106004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE For use in medical balloons and related clinical applications, polymers are usually designed for transparency under illumination with white-light sources. However, when illuminated with ultraviolet (UV) or blue light, most of these materials autofluoresce in the visible range, which can be a concern for modalities that rely on tissue autofluorescence for diagnostic or therapeutic purposes. AIM A search for published information on spectral properties of polymers that can be used for medical balloon manufacturing revealed a scarcity of published information on this subject. The aim of these studies was to address this gap. APPROACH The autofluorescence properties of polymers used in medical balloon manufacturing were examined for their suitability for hyperspectral imaging and related applications. Excitation-emission matrices of different balloon materials were acquired within the 320- to 620-nm spectral range. In parallel, autofluorescence profiles from the 420- to 620-nm range were extracted from hyperspectral datasets of the same samples illuminated with UV light. The list of tested polymers included polyurethanes, nylon, polyethylene terephthalate (PET), polyether block amide (PEBAX), vulcanized silicone, thermoplastic elastomers with and without talc, and cyclic olefin copolymers, known by their trade name TOPAS. RESULTS Each type of polymer exhibited a specific pattern of autofluorescence. Polyurethanes, PET, and thermoplastic elastomers containing talc had the highest autofluorescence values, while sheets made of nylon, PEBAX, and TOPAS exhibited negligible autofluorescence. Hyperspectral imaging was used to illustrate how the choice of specific balloon material can impact the ability of principal component analysis to reveal the ablated cardiac tissue. CONCLUSIONS The data revealed significant differences between autofluorescence profiles of the polymers and pointed to the most promising balloon materials for clinical implementation of approaches that depend on tissue autofluorescence.
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Affiliation(s)
- Huda Asfour
- The George Washington University, Department of Pharmacology and Physiology, Washington, DC, United States
| | - Jeremy Otridge
- The George Washington University, Department of Pharmacology and Physiology, Washington, DC, United States
| | - Robert Thomasian
- The George Washington University, Department of Pharmacology and Physiology, Washington, DC, United States
| | - Cinnamon Larson
- Nocturnal Product Development, LLC, Durham, North Carolina, United States
| | - Narine Sarvazyan
- The George Washington University, Department of Pharmacology and Physiology, Washington, DC, United States
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Liu Y, Hanley T, Chen H, Long SR, Gambhir SS, Cheng Z, Wu JC, Fakhri GE, Anvari B, Zaman RT. Non-Invasive Photoacoustic Imaging of In Vivo Mice with Erythrocyte Derived Optical Nanoparticles to Detect CAD/MI. Sci Rep 2020; 10:5983. [PMID: 32249814 PMCID: PMC7136251 DOI: 10.1038/s41598-020-62868-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 03/19/2020] [Indexed: 11/09/2022] Open
Abstract
Coronary artery disease (CAD) causes mortality and morbidity worldwide. We used near-infrared erythrocyte-derived transducers (NETs), a contrast agent, in combination with a photoacoustic imaging system to identify the locations of atherosclerotic lesions and occlusion due to myocardial-infarction (MI). NETs (≈90 nm diameter) were fabricated from hemoglobin-depleted mice erythrocyte-ghosts and doped with Indocyanine Green (ICG). Ten weeks old male C57BL/6 mice (n = 9) underwent left anterior descending (LAD) coronary artery ligation to mimic vulnerable atherosclerotic plaques and their rupture leading to MI. 150 µL of NETs (20 µM ICG,) was IV injected via tail vein 1-hour prior to photoacoustic (PA) and fluorescence in vivo imaging by exciting NETs at 800 nm and 650 nm, respectively. These results were verified with histochemical analysis. We observed ≈256-fold higher PA signal from the accumulated NETs in the coronary artery above the ligation. Fluorescence signals were detected in LAD coronary, thymus, and liver. Similar signals were observed when the chest was cut open. Atherosclerotic lesions exhibited inflammatory cells. Liver demonstrated normal portal tract, with no parenchymal necrosis, inflammation, fibrosis, or other pathologic changes, suggesting biocompatibility of NETs. Non-invasively detecting atherosclerotic plaques and stenosis using NETs may lay a groundwork for future clinical detection and improving CAD risk assessment.
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Affiliation(s)
- Yonggang Liu
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Taylor Hanley
- Department of Bioengineering, University of California, Riverside, CA, USA
| | - Hao Chen
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Steven R Long
- Department of Pathology, University of California, San Francisco, CA, United States
| | - Sanjiv S Gambhir
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA, USA
- Department of Bioengineering, Stanford University School of Medicine, Stanford, CA, USA
| | - Zhen Cheng
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Joseph C Wu
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Georges El Fakhri
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Boston, MA, USA
| | - Bahman Anvari
- Department of Bioengineering, University of California, Riverside, CA, USA.
| | - Raiyan T Zaman
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Bioengineering, Stanford University School of Medicine, Stanford, CA, USA.
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Zhou G, Lim ZH, Qi Y, Zhou G. Single-Pixel MEMS Imaging Systems. MICROMACHINES 2020; 11:E219. [PMID: 32093324 PMCID: PMC7074650 DOI: 10.3390/mi11020219] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 11/16/2022]
Abstract
Single-pixel imaging technology is an attractive technology considering the increasing demand of imagers that can operate in wavelengths where traditional cameras have limited efficiency. Meanwhile, the miniaturization of imaging systems is also desired to build affordable and portable devices for field applications. Therefore, single-pixel imaging systems based on microelectromechanical systems (MEMS) is an effective solution to develop truly miniaturized imagers, owing to their ability to integrate multiple functionalities within a small device. MEMS-based single-pixel imaging systems have mainly been explored in two research directions, namely the encoding-based approach and the scanning-based approach. The scanning method utilizes a variety of MEMS scanners to scan the target scenery and has potential applications in the biological imaging field. The encoding-based system typically employs MEMS modulators and a single-pixel detector to encode the light intensities of the scenery, and the images are constructed by harvesting the power of computational technology. This has the capability to capture non-visible images and 3D images. Thus, this review discusses the two approaches in detail, and their applications are also reviewed to evaluate the efficiency and advantages in various fields.
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Affiliation(s)
- Guangcan Zhou
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
| | - Zi Heng Lim
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
| | - Yi Qi
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
| | - Guangya Zhou
- Micro and Nano Systems Initiative, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore; (G.Z.); (Z.H.L.); (Y.Q.)
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Franchi F, Olthoff M, Krier J, Noble C, Al-Hijji M, Ramaswamy V, Witt T, Burke M, Benscoter M, Lerman A, Sandhu GS, Rodriguez-Porcel M. A Metabolic Intravascular Platform to Study FDG Uptake in Vascular Injury. Cardiovasc Eng Technol 2020; 11:328-336. [PMID: 32002814 DOI: 10.1007/s13239-020-00457-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/24/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE Metabolic alterations underlie many pathophysiological conditions, and their understanding is critical for the development of novel therapies. Although the assessment of metabolic changes in vivo has been historically challenging, recent developments in molecular imaging have allowed us to study novel metabolic research concepts directly in the living subject, bringing us closer to patients. However, in many instances, there is need for sensors that are in close proximity to the organ under investigation, for example to study vascular metabolism. METHODS In this study, we developed and validated a metabolic detection platform directly in the living subject under an inflammatory condition. The signal collected by a scintillating fiber is amplified using a photomultiplier tube and decodified by an in-house tunable analysis platform. For in vivo testing, we based our experiments on the metabolic characteristics of macrophages, cells closely linked to inflammation and avid for glucose and its analog 18F-fluorodeoxyglucose (18F-FDG). The sensor was validated in New Zealand rabbits, in which inflammation was induced by either a) high cholesterol (HC) diet for 16 weeks or b) vascular balloon endothelial denudation followed by HC diet. RESULTS There was no difference in weight, hemodynamics, blood pressure, or heart rate between the groups. Vascular inflammation was detected by the metabolic sensor (Inflammation: 0.60 ± 0.03 AU vs. control: 0.48 ± 0.03 AU, p = 0.01), even though no significant inflammation/atherosclerosis was detected by intravascular ultrasound, underscoring the high sensitivity of the system. These findings were confirmed by the presence of macrophages on ex vivo aortic tissue staining. CONCLUSION In this study, we validated a tunable very sensitive metabolic sensor platform that can be used for the detection of vascular metabolism, such as inflammation. This sensor can be used not only for the detection of macrophage activity but, with alternative probes, it could allow the detection of other pathophysiological processes.
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Affiliation(s)
- F Franchi
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA.
| | - M Olthoff
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - J Krier
- Department of Physiology and Biomedical Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
| | - C Noble
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - M Al-Hijji
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - V Ramaswamy
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - T Witt
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - M Burke
- Division of Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
| | - M Benscoter
- Division of Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
| | - A Lerman
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - G S Sandhu
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - M Rodriguez-Porcel
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
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Zaman RT, Yousefi S, Chibana H, Ikeno F, Long SR, Gambhir SS, Chin FT, McConnell MV, Xing L, Yeung A. In Vivo Translation of the CIRPI System: Revealing Molecular Pathology of Rabbit Aortic Atherosclerotic Plaques. J Nucl Med 2019; 60:1308-1316. [PMID: 30737298 DOI: 10.2967/jnumed.118.222471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/13/2018] [Indexed: 01/13/2023] Open
Abstract
Thin-cap fibroatheroma (TCFA) are the unstable lesions in coronary artery disease that are prone to rupture, resulting in substantial morbidity and mortality worldwide. However, their small size and complex morphologic and biologic features make early detection and risk assessment difficult. We tested our newly developed catheter-based Circumferential-Intravascular-Radioluminescence-Photoacoustic-Imaging (CIRPI) system in vivo to enable detection and characterization of vulnerable plaque structure and biology in rabbit abdominal aorta. Methods: The CIRPI system includes a novel optical probe combining circumferential radioluminescence imaging and photoacoustic tomography (PAT). The probe's CaF2:Eu-based scintillating imaging window captures radioluminescence images (360° view) of plaques by detecting β-particles during 18F-FDG decay. A tunable laser-based PAT characterizes tissue constituents of plaque at 7 different wavelengths-540 and 560 nm (calcification), 920 nm (cholesteryl ester), 1040 nm (phospholipids), 1180 nm (elastin/collagen), 1210 nm (cholesterol), and 1235 nm (triglyceride). A single B-scan is concatenated from 330 A-lines captured during a 360° rotation. The abdominal aorta was imaged in vivo in both atherosclerotic rabbits (Watanabe Heritable Hyper Lipidemic [WHHL], 13-mo-old male, n = 5) and controls (New Zealand White, n = 2). Rabbits were fasted for 6 h before 5.55 × 107 Bq (1.5 mCi) of 18F-FDG were injected 1 h before the imaging procedure. Rabbits were anesthetized, and the right or left common carotid artery was surgically exposed. An 8 French catheter sheath was inserted into the common carotid artery, and a 0.035-cm (0.014-in) guidewire was advanced to the iliac artery, guided by x-ray fluoroscopy. A bare metal stent was implanted in the dorsal abdominal aorta as a landmark, followed by the 7 French imaging catheters that were advanced up to the proximal stent edge. Our CIRPI and clinical optical coherence tomography (OCT) were performed using pullback and nonocclusive flushing techniques. After imaging with the CIRPI system, the descending aorta was flushed with contrast agent, and OCT images were obtained with a pullback speed of 20 mm/s, providing images at 100 frames/s. Results were verified with histochemical analysis. Results: Our CIRPI system successfully detected the locations and characterized both stable and vulnerable aortic plaques in vivo among all WHHL rabbits. Calcification was detected from the stable plaque (540 and 560 nm), whereas TCFA exhibited phospholipids/cholesterol (1040 nm, 1210 nm). These findings were further verified with the clinical OCT system showing an area of low attenuation filled with lipids within TCFA. PAT images illustrated broken elastic fiber/collagen that could be verified with the histochemical analysis. All WHHL rabbits exhibited sparse to severe macrophages. Only 4 rabbits showed both moderate-to-severe level of calcifications and cholesterol clefts. However, all rabbits exhibited broken elastic fibers and collagen deposition. Control rabbits showed normal wall thickness with no presence of plaque tissue compositions. These findings were verified with OCT and histochemical analysis. Conclusion: Our novel multimodality hybrid system has been successfully translated to in vivo evaluation of atherosclerotic plaque structure and biology in a preclinical rabbit model. This system proposed a paradigm shift that unites molecular and pathologic imaging technologies. Therefore, the system may enhance the clinical evaluation of TCFA, as well as expand our understanding of coronary artery disease.
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Affiliation(s)
- Raiyan T Zaman
- Department of Radiology, Harvard Medical School, Boston, Massachusetts .,Gordon Center for Medical Imaging, Massachusetts General Hospital, Boston, Massachusetts.,Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Siavash Yousefi
- Division of Medical Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Hidetoshi Chibana
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Fumiaki Ikeno
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Steven R Long
- Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Sanjiv S Gambhir
- Department of Radiology, Stanford University School of Medicine, Stanford, California.,Molecular Imaging Program at Stanford University (MIPS), Stanford University School of Medicine, Stanford, California.,Department of Bioengineering, Stanford University Schools of Medicine and of Engineering, Stanford, California; and
| | - Frederick T Chin
- Department of Radiology, Stanford University School of Medicine, Stanford, California.,Molecular Imaging Program at Stanford University (MIPS), Stanford University School of Medicine, Stanford, California
| | - Michael V McConnell
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California.,Molecular Imaging Program at Stanford University (MIPS), Stanford University School of Medicine, Stanford, California.,Verily Life Sciences, San Francisco, California
| | - Lei Xing
- Division of Medical Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.,Molecular Imaging Program at Stanford University (MIPS), Stanford University School of Medicine, Stanford, California
| | - Alan Yeung
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
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MEMS Actuators for Optical Microendoscopy. MICROMACHINES 2019; 10:mi10020085. [PMID: 30682852 PMCID: PMC6412441 DOI: 10.3390/mi10020085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/26/2018] [Accepted: 12/28/2018] [Indexed: 01/21/2023]
Abstract
Growing demands for affordable, portable, and reliable optical microendoscopic imaging devices are attracting research institutes and industries to find new manufacturing methods. However, the integration of microscopic components into these subsystems is one of today's challenges in manufacturing and packaging. Together with this kind of miniaturization more and more functional parts have to be accommodated in ever smaller spaces. Therefore, solving this challenge with the use of microelectromechanical systems (MEMS) fabrication technology has opened the promising opportunities in enabling a wide variety of novel optical microendoscopy to be miniaturized. MEMS fabrication technology enables abilities to apply batch fabrication methods with high-precision and to include a wide variety of optical functionalities to the optical components. As a result, MEMS technology has enabled greater accessibility to advance optical microendoscopy technology to provide high-resolution and high-performance imaging matching with traditional table-top microscopy. In this review the latest advancements of MEMS actuators for optical microendoscopy will be discussed in detail.
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Role of local coronary blood flow patterns and shear stress on the development of microvascular and epicardial endothelial dysfunction and coronary plaque. Curr Opin Cardiol 2018; 33:638-644. [DOI: 10.1097/hco.0000000000000571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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