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Albrecht W, Arslan Irmak E, Altantzis T, Pedrazo-Tardajos A, Skorikov A, Deng TS, van der Hoeven JES, van Blaaderen A, Van Aert S, Bals S. 3D Atomic-Scale Dynamics of Laser-Light-Induced Restructuring of Nanoparticles Unraveled by Electron Tomography. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2100972. [PMID: 34247423 DOI: 10.1002/adma.202100972] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/15/2021] [Indexed: 06/13/2023]
Abstract
Understanding light-matter interactions in nanomaterials is crucial for optoelectronic, photonic, and plasmonic applications. Specifically, metal nanoparticles (NPs) strongly interact with light and can undergo shape transformations, fragmentation and ablation upon (pulsed) laser excitation. Despite being vital for technological applications, experimental insight into the underlying atomistic processes is still lacking due to the complexity of such measurements. Herein, atomic resolution electron tomography is performed on the same mesoporous-silica-coated gold nanorod, before and after femtosecond laser irradiation, to assess the missing information. Combined with molecular dynamics (MD) simulations based on the experimentally determined 3D atomic-scale morphology, the complex atomistic rearrangements, causing shape deformations and defect generation, are unraveled. These rearrangements are simultaneously driven by surface diffusion, facet restructuring, and strain formation, and are influenced by subtleties in the atomic distribution at the surface.
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Affiliation(s)
- Wiebke Albrecht
- EMAT and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, Utrecht, 3584 CC, The Netherlands
| | - Ece Arslan Irmak
- EMAT and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
| | - Thomas Altantzis
- EMAT and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
| | - Adrián Pedrazo-Tardajos
- EMAT and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
| | - Alexander Skorikov
- EMAT and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
| | - Tian-Song Deng
- School of Electronics and Information Engineering, Hangzhou Dianzi University, No. 1158, 2nd Avenue, Baiyang Street, Hangzhou, 310018, China
| | - Jessi E S van der Hoeven
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, Utrecht, 3584 CC, The Netherlands
| | - Alfons van Blaaderen
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, Utrecht, 3584 CC, The Netherlands
| | - Sandra Van Aert
- EMAT and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
| | - Sara Bals
- EMAT and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
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2
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Liu S, Zhang R, Zheng Z, Zheng Y. Electromagnetic⁻Acoustic Sensing for Biomedical Applications. SENSORS (BASEL, SWITZERLAND) 2018; 18:E3203. [PMID: 30248969 PMCID: PMC6210000 DOI: 10.3390/s18103203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/20/2018] [Indexed: 12/29/2022]
Abstract
This paper reviews the theories and applications of electromagnetic⁻acoustic (EMA) techniques (covering light-induced photoacoustic, microwave-induced thermoacoustic, magnetic-modulated thermoacoustic, and X-ray-induced thermoacoustic) belonging to the more general area of electromagnetic (EM) hybrid techniques. The theories cover excitation of high-power EM field (laser, microwave, magnetic field, and X-ray) and subsequent acoustic wave generation. The applications of EMA methods include structural imaging, blood flowmetry, thermometry, dosimetry for radiation therapy, hemoglobin oxygen saturation (SO₂) sensing, fingerprint imaging and sensing, glucose sensing, pH sensing, etc. Several other EM-related acoustic methods, including magnetoacoustic, magnetomotive ultrasound, and magnetomotive photoacoustic are also described. It is believed that EMA has great potential in both pre-clinical research and medical practice.
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Affiliation(s)
- Siyu Liu
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Ruochong Zhang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Zesheng Zheng
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Yuanjin Zheng
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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3
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de Hoop H, Yoon H, Kubelick K, Emelianov S. Photoacoustic speckle tracking for motion estimation and flow analysis. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 30215245 PMCID: PMC6170141 DOI: 10.1117/1.jbo.23.9.096001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 08/20/2018] [Indexed: 05/29/2023]
Abstract
This study explores photoacoustic (PA) speckle tracking to characterize flow as an alternative to ultrasound (US) speckle tracking or current PA flow imaging methods. In cases where tracking of submicrometer particles is required, the US signal-to-noise ratio and contrast might be low due to limited reflectivity of subwavelength size targets at low concentrations. However, it may be possible to perform more accurate velocimetry using PAs due to different contrast mechanisms utilized in PA imaging. Here, we introduce a PA-based speckle tracking method that overcomes the directional dependence of Doppler imaging and the limited field of view of current correlation-based methods used in PA flow imaging. The feasibility of this method is demonstrated in a potential application-minimally invasive diagnosis of ventricular shunt malfunction, where the velocity of optically absorbing particles was estimated in a shunt catheter using block matching of PA and US signals. Overall, our study demonstrates the potential of the PA-based motion tracking method under various flow rates where US imaging cannot be effectively used for specking tracking because of its low contrast and low signal-to-noise ratio.
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Affiliation(s)
- Hein de Hoop
- Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, Georgia, United States
- Eindhoven University of Technology, Department of Biomedical Engineering, Cardiovascular Biomechanics Group, The Netherlands
| | - Heechul Yoon
- Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, Georgia, United States
| | - Kelsey Kubelick
- Georgia Institute of Technology and Emory University School of Medicine, The Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Stanislav Emelianov
- Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, Georgia, United States
- Georgia Institute of Technology and Emory University School of Medicine, The Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
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4
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Albrecht W, Deng TS, Goris B, van Huis M, Bals S, van Blaaderen A. Single Particle Deformation and Analysis of Silica-Coated Gold Nanorods before and after Femtosecond Laser Pulse Excitation. NANO LETTERS 2016; 16:1818-25. [PMID: 26871607 PMCID: PMC4973961 DOI: 10.1021/acs.nanolett.5b04851] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We performed single particle deformation experiments on silica-coated gold nanorods under femtosecond (fs) illumination. Changes in the particle shape were analyzed by electron microscopy and associated changes in the plasmon resonance by electron energy loss spectroscopy. Silica-coated rods were found to be more stable compared to uncoated rods but could still be deformed via an intermediate bullet-like shape for silica shell thicknesses of 14 nm. Changes in the size ratio of the rods after fs-illumination resulted in blue-shifting of the longitudinal plasmon resonances. Two-dimensional spatial mapping of the plasmon resonances revealed that the flat side of the bullet-like particles showed a less pronounced longitudinal plasmonic electric field enhancement. These findings were confirmed by finite-difference time-domain (FDTD) simulations. Furthermore, at higher laser fluences size reduction of the particles was found as well as for particles that were not completely deformed yet.
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Affiliation(s)
- Wiebke Albrecht
- Soft Condensed
Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
- E-mail:
| | - Tian-Song Deng
- Soft Condensed
Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - Bart Goris
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Marijn
A. van Huis
- Soft Condensed
Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - Sara Bals
- Electron
Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Alfons van Blaaderen
- Soft Condensed
Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
- E-mail:
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5
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van den Berg P, Daoudi K, Steenbergen W. Review of photoacoustic flow imaging: its current state and its promises. PHOTOACOUSTICS 2015; 3:89-99. [PMID: 26640771 PMCID: PMC4595496 DOI: 10.1016/j.pacs.2015.08.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/24/2015] [Accepted: 08/02/2015] [Indexed: 05/04/2023]
Abstract
Flow imaging is an important method for quantification in many medical imaging modalities, with applications ranging from estimating wall shear rate to detecting angiogenesis. Modalities like ultrasound and optical coherence tomography both offer flow imaging capabilities, but suffer from low contrast to red blood cells and are sensitive to clutter artefacts. Photoacoustic imaging (PAI) is a relatively new field, with a recent interest in flow imaging. The recent enthusiasm for PA flow imaging is due to its intrinsic contrast to haemoglobin, which offers a new spin on existing methods of flow imaging, and some unique approaches in addition. This review article will delve into the research on photoacoustic flow imaging, explain the principles behind the many techniques and comment on their individual advantages and disadvantages.
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Webb JA, Bardhan R. Emerging advances in nanomedicine with engineered gold nanostructures. NANOSCALE 2014; 6:2502-30. [PMID: 24445488 DOI: 10.1039/c3nr05112a] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Gold nanostructures possess unique characteristics that enable their use as contrast agents, as therapeutic entities, and as scaffolds to adhere functional molecules, therapeutic cargo, and targeting ligands. Due to their ease of synthesis, straightforward surface functionalization, and non-toxicity, gold nanostructures have emerged as powerful nanoagents for cancer detection and treatment. This comprehensive review summarizes the progress made in nanomedicine with gold nanostructures (1) as probes for various bioimaging techniques including dark-field, one-photon and two-photon fluorescence, photothermal optical coherence tomography, photoacoustic tomography, positron emission tomography, and surface-enhanced Raman scattering based imaging, (2) as therapeutic components for photothermal therapy, gene and drug delivery, and radiofrequency ablation, and (3) as a theranostic platform to simultaneously achieve both cancer detection and treatment. Distinct from other published reviews, this article also discusses the recent advances of gold nanostructures as contrast agents and therapeutic actuators for inflammatory diseases including atherosclerotic plaque and arthritis. For each of the topics discussed above, the fundamental principles and progress made in the past five years are discussed. The review concludes with a detailed future outlook discussing the challenges in using gold nanostructures, cellular trafficking, and translational considerations that are imperative for rapid clinical viability of plasmonic nanostructures, as well as the significance of emerging technologies such as Fano resonant gold nanostructures in nanomedicine.
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Affiliation(s)
- Joseph A Webb
- Department of Chemical and Biomolecular Engineering Department, Vanderbilt University, Nashville, TN 37235, USA.
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Manohar S, Ungureanu C, Van Leeuwen TG. Gold nanorods as molecular contrast agents in photoacoustic imaging: the promises and the caveats. CONTRAST MEDIA & MOLECULAR IMAGING 2011; 6:389-400. [DOI: 10.1002/cmmi.454] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Srirang Manohar
- Biomedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, Faculty of Science and Technology; University of Twente; PO Box 217; 7500 AE; Enschede; The Netherlands
| | - Constantin Ungureanu
- Biomedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, Faculty of Science and Technology; University of Twente; PO Box 217; 7500 AE; Enschede; The Netherlands
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8
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Abstract
Photoacoustic imaging, which is based on the photoacoustic effect, has developed extensively over the last decade. Possessing many attractive characteristics such as the use of nonionizing electromagnetic waves, good resolution and contrast, portable instrumention, and the ability to partially quantitate the signal, photoacoustic techniques have been applied to the imaging of cancer, wound healing, disorders in the brain, and gene expression, among others. As a promising structural, functional, and molecular imaging modality for a wide range of biomedical applications, photoacoustic imaging can be categorized into two types of systems: photoacoustic tomography (PAT), which is the focus of this article, and photoacoustic microscopy (PAM). We first briefly describe the endogenous (e.g., hemoglobin and melanin) and the exogenous (e.g., indocyanine green [ICG], various gold nanoparticles, single-walled carbon nanotubes [SWNTs], quantum dots [QDs], and fluorescent proteins) contrast agents for photoacoustic imaging. Next, we discuss in detail the applications of nontargeted photoacoustic imaging. Recently, molecular photoacoustic (MPA) imaging has gained significant interest, and a few proof-of-principle studies have been reported. We summarize the current state of the art of MPA imaging, including the imaging of gene expression and the combination of photoacoustic imaging with other imaging modalities. Last, we point out obstacles facing photoacoustic imaging. Although photoacoustic imaging will likely continue to be a highly vibrant research field for years to come, the key question of whether MPA imaging could provide significant advantages over nontargeted photoacoustic imaging remains to be answered in the future.
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Glatz J, Deliolanis NC, Buehler A, Razansky D, Ntziachristos V. Blind source unmixing in multi-spectral optoacoustic tomography. OPTICS EXPRESS 2011; 19:3175-84. [PMID: 21369139 DOI: 10.1364/oe.19.003175] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Multispectral optoacoustic (photoacoustic) tomography (MSOT) is a hybrid modality that can image through several millimeters to centimeters of diffuse tissues, attaining resolutions typical of ultrasound imaging. The method can further identify tissue biomarkers by decomposing the spectral contributions of different photo-absorbing molecules of interest. In this work we investigate the performance of blind source unmixing methods and spectral fitting approaches in decomposing the contributions of fluorescent dyes from the tissue background, based on MSOT measurements in mice. We find blind unmixing as a promising method for accurate MSOT decomposition, suitable also for spectral unmixing in fluorescence imaging. We further demonstrate its capacity with temporal unmixing on real-time MSOT data obtained in-vivo for enhancing the visualization of absorber agent flow in the mouse vascular system.
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Affiliation(s)
- Jürgen Glatz
- Institute for Biological and Medical Imaging, Technische Universität München & Helmholtz Zentrum München, Munich, Germany
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10
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Yao J, Maslov KI, Shi Y, Taber LA, Wang LV. In vivo photoacoustic imaging of transverse blood flow by using Doppler broadening of bandwidth. OPTICS LETTERS 2010; 35:1419-21. [PMID: 20436589 PMCID: PMC2916025 DOI: 10.1364/ol.35.001419] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A method is proposed to measure transverse blood flow by using photoacoustic Doppler broadening of bandwidth. By measuring bovine blood flowing through a plastic tube, the linear dependence of the broadening on the flow speed was validated. The blood flow of the microvasculature in a mouse ear and a chicken embryo (stage 16) was also studied.
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Yao J, Wang LV. Transverse flow imaging based on photoacoustic Doppler bandwidth broadening. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:021304. [PMID: 20459226 PMCID: PMC2857455 DOI: 10.1117/1.3339953] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We propose a new method to measure transverse flow velocity based on photoacoustic Doppler bandwidth broadening, which is determined by the geometry of the probe-beam and the velocity of the transverse flow. By exploiting pulsed laser excitation and raster motor scanning, three-dimensional structure and flow velocity can be imaged simultaneously. In addition, the flow direction can be determined with bidirectional scanning. In a flowing suspension of red-dyed microspheres (diameter: 6 microm), transverse flow speeds ranging from 0 to 2.5 mms as well as flow direction were measured. A cross-sectional flow image was also obtained with the tube laid in a zigzag pattern.
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Affiliation(s)
- Junjie Yao
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, Campus Box 1097, One Brookings Drive, St. Louis, Missouri 63130, USA
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12
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Chen LC, Wei CW, Souris JS, Cheng SH, Chen CT, Yang CS, Li PC, Lo LW. Enhanced photoacoustic stability of gold nanorods by silica matrix confinement. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:016010. [PMID: 20210456 DOI: 10.1117/1.3292574] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Photoacoustic tomography (PAT) has garnered much attention for its high contrast and excellent spatial resolution of perfused tissues. Gold nanorods (GNRs) have been employed to further enhance the imaging contrast of PAT. However, the photon fluences typically needed for PA wave induction often also result in GNR shape changes that significantly reduce the efficiency of acoustic wave generation. In this work, we propose, synthesize, and evaluate amorphous silica-coated gold nanorods (GNR-Si) in an effort to improve contrast agent stability and ameliorate efficiency loss during photoacoustic (PA) wave induction. TEM and optical absorption spectra measurements of GNR and GNR-Si show that encasing GNRs within amorphous silica provides substantial protection of nanorod conformation from thermal deformation. PA signals generated by GNR-Si demonstrate considerably greater resistance to degradation of signal intensity with repetitive pulsing than do uncoated GNRs, thereby enabling much longer, high-contrast imaging sessions than previously possible. The prolongation of high-contrast imaging, and biocompatibility and easy surface functionalization for targeting ligands afforded by amorphous silica, suggest GNR-Si to be potentially significant for the clinical translation of PAT.
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Affiliation(s)
- Leng-Chun Chen
- National Health Research Institutes, Division of Medical Engineering Research, Zhunan, Miaoli Country, Taiwan
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13
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Hu S, Wang LV. Photoacoustic imaging and characterization of the microvasculature. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:011101. [PMID: 20210427 PMCID: PMC2821418 DOI: 10.1117/1.3281673] [Citation(s) in RCA: 208] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 09/15/2009] [Accepted: 09/21/2009] [Indexed: 05/06/2023]
Abstract
Photoacoustic (optoacoustic) tomography, combining optical absorption contrast and highly scalable spatial resolution (from micrometer optical resolution to millimeter acoustic resolution), has broken through the fundamental penetration limit of optical ballistic imaging modalities-including confocal microscopy, two-photon microscopy, and optical coherence tomography-and has achieved high spatial resolution at depths down to the diffusive regime. Optical absorption contrast is highly desirable for microvascular imaging and characterization because of the presence of endogenous strongly light-absorbing hemoglobin. We focus on the current state of microvascular imaging and characterization based on photoacoustics. We first review the three major embodiments of photoacoustic tomography: microscopy, computed tomography, and endoscopy. We then discuss the methods used to characterize important functional parameters, such as total hemoglobin concentration, hemoglobin oxygen saturation, and blood flow. Next, we highlight a few representative applications in microvascular-related physiological and pathophysiological research, including hemodynamic monitoring, chronic imaging, tumor-vascular interaction, and neurovascular coupling. Finally, several potential technical advances toward clinical applications are suggested, and a few technical challenges in contrast enhancement and fluence compensation are summarized.
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Affiliation(s)
- Song Hu
- Washington University in St. Louis, Department of Biomedical Engineering, St. Louis, Missouri 63130-4899, USA
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14
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Abstract
Photoacoustic tomography (PAT) is probably the fastest growing biomedical imaging technology owing to its capability of high-resolution sensing of rich optical contrast in vivo at depths beyond the optical transport mean free path (~1 mm in the skin). Existing high-resolution optical imaging technologies, such as confocal microscopy and two-photon microscopy, have fundamentally impacted biomedicine but cannot reach such depths. Taking advantage of low ultrasonic scattering, PAT indirectly improves tissue transparency by 100 to 1000 fold and consequently enables deeply penetrating functional and molecular imaging at high spatial resolution. Further, PAT holds the promise of in vivo imaging at multiple length scales ranging from subcellular organelles to organs with the same contrast origin, an important application in multiscale systems biology research.
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Affiliation(s)
- Lihong V Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899
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15
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Mallidi S, Larson T, Tam J, Joshi PP, Karpiouk A, Sokolov K, Emelianov S. Multiwavelength photoacoustic imaging and plasmon resonance coupling of gold nanoparticles for selective detection of cancer. NANO LETTERS 2009; 9:2825-31. [PMID: 19572747 PMCID: PMC2898720 DOI: 10.1021/nl802929u] [Citation(s) in RCA: 275] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Gold nanoparticles targeting epidermal growth factor receptor via antibody conjugation undergo molecular specific aggregation when they bind to receptors on cell surfaces, leading to a red shift in their plasmon resonance frequency. Capitalizing on this effect, we demonstrate the efficacy of the molecular specific photoacoustic imaging technique using subcutaneous tumor-mimicking gelatin implants in ex-vivo mouse tissue. The results of our study suggest that highly selective and sensitive detection of cancer cells is possible using multiwavelength photoacoustic imaging and molecular specific gold nanoparticles.
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Affiliation(s)
| | | | | | | | | | | | - Stanislav Emelianov
- To whom correspondence should be addressed. Telephone: (512) 471-1733. Fax: (512) 471-0616.
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16
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Emelianov SY, Li PC, O'Donnell M. Photoacoustics for molecular imaging and therapy. PHYSICS TODAY 2009; 62:34-39. [PMID: 20523758 PMCID: PMC2879661 DOI: 10.1063/1.3141939] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Sound waves generated by light are the basis of a sensitive medical imaging technique with applications to cancer diagnosis and treatment.
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17
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Abstract
Recently, there has been growing interest in the development of photoacoustic flow measuring methods aimed to study microvascular blood flow in biological tissue. Here, we describe the M-mode photoacoustic particle flow imaging, using an optical resolution photoacoustic microscope equipped with a high-repetition-rate pulsed dye laser. We studied the flow of a diluted dyed particle suspension in a small tube embedded in a nonscattering medium as well as in a scattering medium simulating biological tissue. Potentially, the method can be applied to detect the flow speed of single red blood cells in a capillary.
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Affiliation(s)
- Hui Fang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA
| | - Lihong V. Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA
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18
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Liao CK, Huang SW, Wei CW, Li PC. Nanorod-based flow estimation using a high-frame-rate photoacoustic imaging system. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:064006. [PMID: 18163822 DOI: 10.1117/1.2812704] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A quantitative flow measurement method that utilizes a sequence of photoacoustic images is described. The method is based on the use of gold nanorods as a contrast agent for photoacoustic imaging. The peak optical absorption wavelength of a gold nanorod depends on its aspect ratio, which can be altered by laser irradiation (we establish a wash-in flow estimation method of this process). The concentration of nanorods with a particular aspect ratio inside a region of interest is affected by both laser-induced shape changes and replenishment of nanorods at a rate determined by the flow velocity. In this study, the concentration is monitored using a custom-designed, high-frame-rate photoacoustic imaging system. This imaging system consists of fiber bundles for wide area laser irradiation, a laser ultrasonic transducer array, and an ultrasound front-end subsystem that allows acoustic data to be acquired simultaneously from 64 transducer elements. Currently, the frame rate of this system is limited by the pulse-repetition frequency of the laser (i.e., 15 Hz). With this system, experimental results from a chicken breast tissue show that flow velocities from 0.125 to 2 mms can be measured with an average error of 31.3%.
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Affiliation(s)
- Chao-Kang Liao
- National Taiwan University, Department of Electrical Engineering, Taipei 106, Taiwan
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19
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Li PC, Wei CW, Liao CK, Chen CD, Pao KC, Wang CRC, Wu YN, Shieh DB. Photoacoustic imaging of multiple targets using gold nanorods. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2007; 54:1642-7. [PMID: 17703668 DOI: 10.1109/tuffc.2007.435] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Photoacoustic (PA) imaging has been used mainly for anatomical and functional imaging. Although functionalized nanoparticles also have been developed for PA molecular imaging, only single targeting has been demonstrated. In this study, PA imaging of multiple targets using gold nanorods is demonstrated experimentally using HER2 and CXCR4 as target molecules. The two corresponding monoclonal antibodies were conjugated to two types of gold nanorod with different aspect ratios. Gold nanorods with mean aspect ratios of 5.9 and 3.7 exhibited peak optical absorptions at 1000 and 785 nm, respectively. Appropriate selection of laser irradiation wavelength enhances PA signals by 7-12 dB and allows signals from gold nanorods corresponding to specific bindings to be distinguished. This approach potentially allows the expression levels of different oncogenes of cancer cells to be revealed simultaneously.
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20
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Wei CW, Huang SW, Wang CRC, Li PC. Photoacoustic flow measurements based on wash-in analysis of gold nanorods. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2007; 54:1131-41. [PMID: 17571812 DOI: 10.1109/tuffc.2007.367] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this study, photoacoustic flow measurement methods based on wash-in analysis are presented. These methods use the rod-to-sphere shape transformations of gold nanorods induced by pulsed-laser irradiation. Due to the shape dependence of the optical absorption of the gold nanorods, these shape transitions are associated with a change in the peak optical absorption wavelength. Pulsed-laser irradiation at the wavelength corresponding to the peak optical absorption of the original gold nanorods allows the particles that undergo shape changes to be viewed as "being destructed" by the laser irradiation at that wavelength, hence, flow information can be derived from the change in ultrasound intensity that is directly related to the wash-in rate of the gold nanorods and the laser intensity. Two flow estimation methods based on the wash-in analysis are described. The first method first applies high-energy laser pulses that induce shape changes in all the nanorods. A series of low-energy pulses then are applied to monitor the acoustic signal change as new nanorods flow into the region of interest. The second method uses single-energy laser pulses such that the "destruction" and "detection" are performed simultaneously. The simulation results show that it is valid to fit the time-intensity curves by exponential models. To demonstrate the validity of the proposed methods, an Nd:YAG pulsed laser operating at 1064 nm was used for optical irradiation, and a 1-MHz ultrasonic transducer was used for acoustic detection. Gold nanorods with a peak optical absorption at 1018 nm and a concentration of 0.26 nM were used to estimate flow velocities ranging from 0.35 to 2.83 mm/s. The linear regression results show that the correlation coefficients between the measured velocities and the true values are close to unity (> or = 0.94), thus demonstrating the feasibility of the proposed photoacoustic techniques for relative flow estimation.
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Affiliation(s)
- Chen-Wei Wei
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
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