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Cao T, Wei CW, Cen MJ, Guo B, Kim YJ, Zhang S, Qiu CW. A reprogrammable multifunctional chalcogenide guided-wave lens. Nanoscale 2018; 10:17053-17059. [PMID: 29869667 DOI: 10.1039/c8nr02100g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The transformation optics (TO) technique, which establishes an equivalence between a curved space and a spatial distribution of inhomogeneous constitutive parameters, has enabled an extraordinary paradigm for manipulating wave propagation. However, extreme constitutive parameters, as well as a static nature, inherently limit the simultaneous achievement of broadband performance, ultrafast reconfigurability and versatile reprogrammable functions. Here, we integrate the TO technique with an active phase-change chalcogenide to achieve a reconfigurable multi-mode guided-wave lens. The lens is made of a Rinehart-shaped curved waveguide with an effective refractive index gradient profile through partially crystallizing Ge2Sb2Te5. Upon changing the bias time of the external voltage imparted to the Ge2Sb2Te5 segments, the refractive index gradient profile can be tuned with a transformative platform for various functions for visible light. The electrically reprogrammable multi-mode guided-wave lens is capable of dynamically acquiring various functionalities with an ultrafast response time. Our findings may offer a significant step forward by providing a universal method to obtain ultrafast and highly versatile guided-wave manipulation, such as in Einstein rings, cloaking, Maxwell fish-eye lenses and Luneburg lenses.
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Affiliation(s)
- Tun Cao
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, 116024, China.
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2
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Cao T, Li Y, Wei CW, Qiu YM. Numerical study of tunable enhanced chirality in multilayer stack achiral phase-change metamaterials. Opt Express 2017; 25:9911-9925. [PMID: 28468371 DOI: 10.1364/oe.25.009911] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We numerically demonstrate a multiband circular dichroism (CD) by tilting achiral metamaterials (MMs) composed of an elliptical nanoholes array (ENA) penetrating through metal/ phase-change material (PCM) /metal multilayer stack, with respect to the incident light. The CD spectrum can be actively tuned across a wide range from the near-infrared (NIR) to mid-infrared (MIR) regime by transiting the state of the PCM (Ge2Sb2Te5) from amorphous to crystalline. Thus, it can switch on/off a multiband chiroptical response in the infrared region. Our simulation also elucidates that the achiral multilayer stack MMs, which have strong magnetic resonances, can enhance the optical chirality inside the elliptical apertures for both amorphous and crystalline states. The switching of the enhanced chirality may pave the way to manipulate electromagnetic waves, such as tunable circular polarizers, chiroptical spectroscopy, and chiral biosensors.
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Yoon SJ, Hsieh BY, Wei CW, Nguyen TM, Arnal B, Pelivanov I, O'Donnell M. Optimization of the laser irradiation pattern in a high frame rate integrated photoacoustic / ultrasound (PAUS) imaging system. IEEE Int Ultrason Symp 2015; 2015:10.1109/ultsym.2015.0032. [PMID: 35432748 PMCID: PMC9008801 DOI: 10.1109/ultsym.2015.0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
To integrate real-time photoacoustics (PA) into ultrasound (US) scanners and accelerate clinical translation of combined PAUS imaging, we previously developed a system using a portable, low-cost, low pulse energy, high-repetition rate laser (~1kHz) with a 1D galvo-mirror for rapid laser beam scanning over the imaging area. However, the frame rate and pulse energy are limited because of regulations on the radiance (1 W/cm2). Therefore, a laser scan scheme needs to be optimized to provide high frame rate within this safety limit. In addition, the laser light should be evenly distributed to minimize any artifacts caused by the scanning approach. In this paper, we calculated the laser light distribution using 3D Monte Carlo simulation and further developed the system to scan the laser beam in elevation as well as laterally using a 2-dimensional galvo-mirror scanner to achieve higher frame rates within the radiance safety limit. Insertion of a needle into chicken breast tissue was used to demonstrate our optimized scan scheme.
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Affiliation(s)
- Soon Joon Yoon
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Bao-Yu Hsieh
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Chen-Wei Wei
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Thu-Mai Nguyen
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Bastien Arnal
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Ivan Pelivanov
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Matthew O'Donnell
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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Pelivanov I, Shtokolov A, Wei CW, O'Donnell M. A 1 kHz A-scan rate pump-probe laser-ultrasound system for robust inspection of composites. IEEE Trans Ultrason Ferroelectr Freq Control 2015; 62:1696-1703. [PMID: 26415130 DOI: 10.1109/tuffc.2015.007110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We recently built a fiber-optic laser-ultrasound (LU) scanner for nondestructive evaluation (NDE) of aircraft composites and demonstrated its greatly improved sensitivity and stability compared with current noncontact systems. It is also very attractive in terms of cost, stability to environmental noise and surface roughness, simplicity in adjustment, footprint, and flexibility. A new type of a balanced fiber-optic Sagnac interferometer is a key component of this all-optical LU pump-probe system. Very high A-scan rates can be achieved because no reference arm or stabilization feedback are needed. Here, we demonstrate LU system performance at 1000 A-scans/s combined with a fast 2-D translator operating at a scanning speed of 100 mm/s with a peak acceleration of 10 m/s(2) in both lateral directions to produce parallel B-scans at high rates. The fast scanning strategy is described in detail. The sensitivity of this system, in terms of noise equivalent pressure, was further improved to be only 8.3 dB above the Nyquist thermal noise limit. To our knowledge, this is the best reported sensitivity for a noncontact ultrasonic detector of this dimension used to inspect aircraft composites.
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Cao T, Wei CW, Mao LB, Wang S. Tuning of giant 2D-chiroptical response using achiral metasurface integrated with graphene. Opt Express 2015; 23:18620-18629. [PMID: 26191920 DOI: 10.1364/oe.23.018620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Tuning the chiroptical response of a molecule is crucial for detecting the material's chirality. Here, we demonstrate a pronounced circular conversion dichroism (CCD) by using an achiral metasurface (AMS) which is composed of a rectangular reflectarray of Au squares separated from a continuous Au film by a dielectric interlayer. This extrinsically 2D chirality originates from the mutual orientation between the AMS and oblique incident wave. The AMS is further incorporated with graphene to tune the CCD spectra in the mid-infrared (MIR) region by electrically modulating the graphene's Fermi level. This approach offers a high fabrication tolerance and will be a promising candidate for controlling electromagnetic (EM) waves in the MIR region from 1500 to 3000 nm.
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Arnal B, Perez C, Wei CW, Xia J, Lombardo M, Pelivanov I, Matula TJ, Pozzo LD, O’Donnell M. Sono-photoacoustic imaging of gold nanoemulsions: Part I. Exposure thresholds. Photoacoustics 2015; 3:3-10. [PMID: 25893169 PMCID: PMC4398805 DOI: 10.1016/j.pacs.2014.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 11/19/2014] [Accepted: 12/11/2014] [Indexed: 05/04/2023]
Abstract
Integrating high contrast bubbles from ultrasound imaging with plasmonic absorbers from photoacoustic imaging is investigated. Nanoemulsion beads coated with gold nanopsheres (NEB-GNS) are excited with simultaneous light (transient heat at the GNS's) and ultrasound (rarefactional pressure) resulting in a phase transition achievable under different scenarios, enhancing laser-induced acoustic signals and enabling specific detection of nanoprobes at lower concentration. An automated platform allowed dual parameter scans of both pressure and laser fluence while recording broadband acoustic signals. Two types of NEB-GNS and individual GNS were investigated and showed the great potential of this technique to enhance photoacoustic/acoustic signals. The NEB-GNS size distribution influences vaporization thresholds which can be reached at both permissible ultrasound and light exposures at deep penetration and at low concentrations of targets. This technique, called sono-photoacoustics, has great potential for targeted molecular imaging and therapy using compact nanoprobes with potentially high-penetrability into tissue.
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Affiliation(s)
- Bastien Arnal
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- Corresponding author. Tel.: +1 80 96 33 45
| | - Camilo Perez
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA 98105-6698, United States
| | - Chen-Wei Wei
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
| | - Jinjun Xia
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
| | - Michael Lombardo
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- University of Washington, Department of Chemical Engineering, Box 351750, Seattle, WA 98195-1750, United States
| | - Ivan Pelivanov
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- International Laser Center, Moscow State University, Moscow, Russian Federation
| | - Thomas J. Matula
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA 98105-6698, United States
| | - Lilo D. Pozzo
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- University of Washington, Department of Chemical Engineering, Box 351750, Seattle, WA 98195-1750, United States
| | - Matthew O’Donnell
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
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Arnal B, Wei CW, Perez C, Nguyen TM, Lombardo M, Pelivanov I, Pozzo LD, O’Donnell M. Sono-photoacoustic imaging of gold nanoemulsions: Part II. Real time imaging. Photoacoustics 2015; 3:11-9. [PMID: 25893170 PMCID: PMC4398795 DOI: 10.1016/j.pacs.2015.01.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/31/2014] [Accepted: 01/11/2015] [Indexed: 05/05/2023]
Abstract
Photoacoustic (PA) imaging using exogenous agents can be limited by degraded specificity due to strong background signals. This paper introduces a technique called sono-photoacoustics (SPA) applied to perfluorohexane nanodroplets coated with gold nanospheres. Pulsed laser and ultrasound (US) excitations are applied simultaneously to the contrast agent to induce a phase-transition ultimately creating a transient microbubble. The US field present during the phase transition combined with the large thermal expansion of the bubble leads to 20-30 dB signal enhancement. Aqueous solutions and phantoms with very low concentrations of this agent were probed using pulsed laser radiation at diagnostic exposures and a conventional US array used both for excitation and imaging. Contrast specificity of the agent was demonstrated with a coherent differential scheme to suppress US and linear PA background signals. SPA shows great potential for molecular imaging with ultrasensitive detection of targeted gold coated nanoemulsions and cavitation-assisted theranostic approaches.
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Affiliation(s)
- Bastien Arnal
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- Corresponding author. Tel.: +1 2062218330.
| | - Chen-Wei Wei
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
| | - Camilo Perez
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, 1013 NE 40th Street, Seattle, WA 98105-6698, United States
| | - Thu-Mai Nguyen
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
| | - Michael Lombardo
- University of Washington, Department of Chemical Engineering, Box 351750, Seattle, WA 98195-1750, United States
| | - Ivan Pelivanov
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
- International Laser Center, Moscow State University, Moscow, Russian Federation
| | - Lilo D. Pozzo
- University of Washington, Department of Chemical Engineering, Box 351750, Seattle, WA 98195-1750, United States
| | - Matthew O’Donnell
- University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States
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Li J, Arnal B, Wei CW, Shang J, Nguyen TM, O’Donnell M, Gao X. Magneto-optical nanoparticles for cyclic magnetomotive photoacoustic imaging. ACS Nano 2015; 9:1964-76. [PMID: 25658655 PMCID: PMC4610822 DOI: 10.1021/nn5069258] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Photoacoustic imaging has emerged as a highly promising tool to visualize molecular events with deep tissue penetration. Like most other modalities, however, image contrast under in vivo conditions is far from optimal due to background signals from tissue. Using iron oxide-gold core-shell nanoparticles, we have previously demonstrated the concept of magnetomotive photoacoustic (mmPA) imaging, which is capable of dramatically reducing the influence of background signals and producing high-contrast molecular images. Here, we report two significant advances toward clinical translation of this technology. First, we introduce a new class of compact, uniform, magneto-optically coupled core-shell nanoparticles, prepared through localized copolymerization of polypyrrole (PPy) on an iron oxide nanoparticle surface. The resulting iron oxide-PPy nanoparticles feature high colloidal stability and solve the photoinstability and small-scale synthesis problems previously encountered by the gold coating approach. In parallel, we have developed a new generation of mmPA featuring cyclic magnetic motion and ultrasound speckle tracking (USST), whose imaging capture frame rate is several hundred times faster than the photoacoustic speckle tracking (PAST) method we demonstrated previously. These advances enable robust artifact elimination caused by physiologic motions and demonstrate the application of the mmPA technology for in vivo sensitive tumor imaging.
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Affiliation(s)
| | | | | | - Jing Shang
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, United States
| | - Thu-Mai Nguyen
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, United States
| | - Matthew O’Donnell
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, United States
| | - Xiaohu Gao
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, United States
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Wei CW, Nguyen TM, Xia J, Arnal B, Pelivanov I, O'Donnell M. Real-time interleaved photoacoustic/ultrasound (PAUS) imaging for interventional procedure guidance. Proc SPIE Int Soc Opt Eng 2015; 9323:93233J. [PMID: 36247362 PMCID: PMC9565888 DOI: 10.1117/12.2084704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Ultrasound-guided photoacoustic imaging has shown great potential for many clinical applications including vascular visualization, detection of nanoprobes sensing molecular profiles, and guidance of interventional procedures. However, bulky and costly lasers are usually required to provide sufficient pulse energies for deep imaging. The low pulse repetition rate also limits potential real-time applications of integrated photoacoustic/ultrasound (PAUS) imaging. With a compact and low-cost laser operating at a kHz repetition rate, we aim to integrate photoacoustics (PA) into a commercial ultrasound (US) machine utilizing an interleaved scanning approach for clinical translation, with imaging depth up to a few centimeters and frame rates > 30 Hz. Multiple PA sub-frames are formed by scanning laser firings covering a large scan region with a rotating galvo mirror, and then combined into a final frame. Ultrasound pulse-echo beams are interleaved between laser firings/PA receives. The approach was implemented with a diode-pumped laser, a commercial US scanner, and a linear array transducer. Insertion of an 18-gauge needle into a piece of chicken tissue, with subsequent injection of an absorptive agent into the tissue, was imaged with an integrated PAUS frame rate of 30 Hz, covering a 2.8 cm × 2.8 cm imaging plane. Given this real-time image rate and high contrast (> 40 dB at more than 1-cm depth in the PA image), we have demonstrated that this approach is potentially attractive for clinical procedure guidance.
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Affiliation(s)
- Chen-Wei Wei
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Thu-Mai Nguyen
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Jinjun Xia
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Bastien Arnal
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Ivan Pelivanov
- Department of Bioengineering, University of Washington, Seattle, USA
- International Laser Center, Moscow State University, Russian Federation
| | - Matthew O'Donnell
- Department of Bioengineering, University of Washington, Seattle, USA
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Wei CW, Nguyen TM, Xia J, Arnal B, Wong EY, Pelivanov IM, O’Donnell M. Real-time integrated photoacoustic and ultrasound (PAUS) imaging system to guide interventional procedures: ex vivo study. IEEE Trans Ultrason Ferroelectr Freq Control 2015; 62:319-28. [PMID: 25643081 PMCID: PMC4610852 DOI: 10.1109/tuffc.2014.006728] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Because of depth-dependent light attenuation, bulky, low-repetition-rate lasers are usually used in most photoacoustic (PA) systems to provide sufficient pulse energies to image at depth within the body. However, integrating these lasers with real-time clinical ultrasound (US) scanners has been problematic because of their size and cost. In this paper, an integrated PA/US (PAUS) imaging system is presented operating at frame rates >30 Hz. By employing a portable, low-cost, low-pulse-energy (~2 mJ/pulse), high-repetition-rate (~1 kHz), 1053-nm laser, and a rotating galvo-mirror system enabling rapid laser beam scanning over the imaging area, the approach is demonstrated for potential applications requiring a few centimeters of penetration. In particular, we demonstrate here real-time (30 Hz frame rate) imaging (by combining multiple single-shot sub-images covering the scan region) of an 18-gauge needle inserted into a piece of chicken breast with subsequent delivery of an absorptive agent at more than 1-cm depth to mimic PAUS guidance of an interventional procedure. A signal-to-noise ratio of more than 35 dB is obtained for the needle in an imaging area 2.8 × 2.8 cm (depth × lateral). Higher frame rate operation is envisioned with an optimized scanning scheme.
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Arnal B, Wei CW, Nguyen TM, Li J, Pelivanov I, Gao X, O'Donnell M. Cyclic Magnetomotive Photoacoustic/Ultrasound Imaging. Proc SPIE Int Soc Opt Eng 2015; 9323:93230T. [PMID: 36275045 PMCID: PMC9583729 DOI: 10.1117/12.2084906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Magnetomotive photoacoustic/ultrasound imaging has shown superior specificity in visualizing targeted objects at cellular and molecular levels. By detecting magnet-induced displacements, magnetic-particle-targeted objects can be differentiated from background signals insensitive to the magnetic field. Unfortunately, background physiologic motion interferes during measurement, such as cardiac-induced motion and respiration, greatly reducing the robustness of the technique. In this paper, we propose cyclic magnetomotive imaging with narrowband magnetic excitation. By synchronizing magnetic motion with the excitations, targeted objects moving coherently can be distinguished from background static signals and signals moving incoherently. HeLa cells targeted with magnetic nanoparticle-polymer core-shell particles were used as the targets for an initial test. A linear ultrasound array was interfaced with a commercial scanner to acquire a photoacoustic/ultrasound image sequence (maximum 1000 frames per second) during multi-cycle magnetic excitation (0.5 - 40 Hz frequency range) with an electromagnet. An image mask defined by a threshold on the displacement-coherence map was applied to the original images for background suppression. The results show that contrast was increased by more than 60 dB in an in-vitro experiment with the tagged cells fixed in a polyvinyl-alcohol gel and sandwiched between porcine liver tissues. Using a single sided system, cells injected subcutaneously on the back of a mouse were successfully differentiated from the background, with less than 20 μm coherent magnetic induced displacements isolated from millimetric background breathing motion. These results demonstrate the technique's motion robustness for highly sensitive and specific diagnosis.
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Affiliation(s)
- Bastien Arnal
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Chen-Wei Wei
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Thu-Mai Nguyen
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Junwei Li
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Ivan Pelivanov
- Department of Bioengineering, University of Washington, Seattle, USA
- International Laser Center, Moscow State University, Russian Federation
| | - Xiaohu Gao
- Department of Bioengineering, University of Washington, Seattle, USA
| | - Matthew O'Donnell
- Department of Bioengineering, University of Washington, Seattle, USA
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Sheng ZJ, Qin CJ, Wei CW, Miao LC, Hua ZG, Rui C, Lin L, Cai WM. The effect of aerobic exercise and Macrothele raven venom on tumor-bearing mice. Int J Sports Med 2014; 36:93-100. [PMID: 25254897 DOI: 10.1055/s-0034-1385877] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Liver cancer is one of the most common cancers in the world. Macrothele raven venom, a complicated mixture of neurotoxic peptides, proteins and low molecular weight material, has antitumor properties, but its mechanism of action is unknown. Moderate exercise has been shown to shrink tumors and cause a remarkable reduction in the tumor growth rate. In this study, we examined the antitumor effect of Macrothele raven venom in combination with exercise on tumor-bearing mice. Our results demonstrate that aerobic exercise in combination with venom administered at different doses was much more effective in a mouse H22 hepatoma model compared to separate administration of the 2 treatments. The underlying mechanism of this effect may be related to the expression of various tumor suppressor factors.
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Affiliation(s)
- Z J Sheng
- College of Physical Education, Hunan Normal University, Changsha, China
| | - C J Qin
- College of Physical Education, Hunan Normal University, Changsha, China
| | - C W Wei
- College of Physical Education, Hunan Normal University, Changsha, China
| | - L C Miao
- Central Hospital of Shaoyang, Shaoyang, China
| | - Z G Hua
- Central Hospital of Shaoyang, Shaoyang, China
| | - C Rui
- Central Hospital of Shaoyang, Shaoyang, China
| | - L Lin
- College of Physical Education, Hunan Normal University, Changsha, China
| | - W M Cai
- Central Hospital of Shaoyang, Shaoyang, China
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Pelivanov I, Buma T, Xia J, Wei CW, O’Donnell M. NDT of fiber-reinforced composites with a new fiber-optic pump-probe laser-ultrasound system. Photoacoustics 2014; 2:63-74. [PMID: 25302156 PMCID: PMC4182813 DOI: 10.1016/j.pacs.2014.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 01/10/2014] [Accepted: 01/27/2014] [Indexed: 05/19/2023]
Abstract
Laser-ultrasonics is an attractive and powerful tool for the non-destructive testing and evaluation (NDT&E) of composite materials. Current systems for non-contact detection of ultrasound have relatively low sensitivity compared to contact peizotransducers. They are also expensive, difficult to adjust, and strongly influenced by environmental noise. Moreover, laser-ultrasound (LU) systems typically launch only about 50 firings per second, much slower than the kHz level pulse repetition rate of conventional systems. As demonstrated here, most of these drawbacks can be eliminated by combining a new generation of compact, inexpensive, high repetition rate nanosecond fiber lasers with new developments in fiber telecommunication optics and an optimally designed balanced probe beam detector. In particular, a modified fiber-optic balanced Sagnac interferometer is presented as part of a LU pump-probe system for NDT&E of aircraft composites. The performance of the all-optical system is demonstrated for a number of composite samples with different types and locations of inclusions.
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Affiliation(s)
- Ivan Pelivanov
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- International Laser Center, Moscow State University, Moscow, Russian Federation
- Corresponding author at: Department of Bioengineering, University of Washington, Seattle, WA, USA. Tel.: +1 206 504 6609.
| | | | - Jinjun Xia
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Chen-Wei Wei
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Matthew O’Donnell
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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Pelivanov I, Buma T, Xia J, Wei CW, O'Donnell M. A new fiber-optic non-contact compact laser-ultrasound scanner for fast non-destructive testing and evaluation of aircraft composites. J Appl Phys 2014; 115:113105. [PMID: 24737921 PMCID: PMC3971821 DOI: 10.1063/1.4868463] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 03/03/2014] [Indexed: 05/20/2023]
Abstract
Laser ultrasonic (LU) inspection represents an attractive, non-contact method to evaluate composite materials. Current non-contact systems, however, have relatively low sensitivity compared to contact piezoelectric detection. They are also difficult to adjust, very expensive, and strongly influenced by environmental noise. Here, we demonstrate that most of these drawbacks can be eliminated by combining a new generation of compact, inexpensive fiber lasers with new developments in fiber telecommunication optics and an optimally designed balanced probe scheme. In particular, a new type of a balanced fiber-optic Sagnac interferometer is presented as part of an all-optical LU pump-probe system for non-destructive testing and evaluation of aircraft composites. The performance of the LU system is demonstrated on a composite sample with known defects. Wide-band ultrasound probe signals are generated directly at the sample surface with a pulsed fiber laser delivering nanosecond laser pulses at a repetition rate up to 76 kHz rate with a pulse energy of 0.6 mJ. A balanced fiber-optic Sagnac interferometer is employed to detect pressure signals at the same point on the composite surface. A- and B-scans obtained with the Sagnac interferometer are compared to those made with a contact wide-band polyvinylidene fluoride transducer.
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15
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Wei CW, Lombardo M, Larson-Smith K, Pelivanov I, Perez C, Xia J, Matula T, Pozzo D, O'Donnell M. Nonlinear contrast enhancement in photoacoustic molecular imaging with gold nanosphere encapsulated nanoemulsions. Appl Phys Lett 2014; 104:033701. [PMID: 24753620 PMCID: PMC3977873 DOI: 10.1063/1.4862461] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 01/05/2014] [Indexed: 05/18/2023]
Abstract
A composite contrast agent, a nanoemulsion bead with assembled gold nanospheres at the interface, is proposed to improve the specific contrast of photoacoustic molecular imaging. A phase transition in the bead's core is induced by absorption of a nanosecond laser pulse with a fairly low laser fluence (∼3.5 mJ/cm2), creating a transient microbubble through dramatically enhanced thermal expansion. This generates nonlinear photoacoustic signals with more than 10 times larger amplitude compared to that of a linear agent with the same optical absorption. By applying a differential scheme similar to ultrasound pulse inversion, more than 40 dB contrast enhancement is demonstrated with suppression of background signals.
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Affiliation(s)
- Chen-Wei Wei
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
| | - Michael Lombardo
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
| | - Kjersta Larson-Smith
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
| | - Ivan Pelivanov
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA ; International Laser Center, Moscow State University, Moscow, Russian Federation
| | - Camilo Perez
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
| | - Jinjun Xia
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
| | - Thomas Matula
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
| | - Danilo Pozzo
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
| | - Matthew O'Donnell
- Departments of Bioengineering and Chemical Engineering, and Applied Physics Lab, University of Washington, Seattle, Washington 98195, USA
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16
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Abstract
In recent years, conjugated polymers have attracted considerable attention from the imaging community as a new class of contrast agent due to their intriguing structural, chemical, and optical properties. Their size and emission wavelength tunability, brightness, photostability, and low toxicity have been demonstrated in a wide range of in vitro sensing and cellular imaging applications, and have just begun to show impact in in vivo settings. In this Perspective, we summarize recent advances in engineering conjugated polymers as imaging contrast agents, their emerging applications in molecular imaging (referred to as in vivo uses in this paper), as well as our perspectives on future research.
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Affiliation(s)
- Junwei Li
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Jie Liu
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Chen-Wei Wei
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Bin Liu
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Matthew O’Donnell
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Xiaohu Gao
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
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O'Donnell M, Wei CW, Xia J, Pelivanov I, Jia C, Huang SW, Hu X, Gao X. Can molecular imaging enable personalized diagnostics? An example using magnetomotive photoacoustic imaging. Ann Biomed Eng 2013; 41:2237-47. [PMID: 23982280 DOI: 10.1007/s10439-013-0901-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 08/19/2013] [Indexed: 01/28/2023]
Abstract
The advantages of photoacoustic (PA) imaging, including low cost, non-ionizing operation, and sub-mm spatial resolution at centimeters depth, make it a promising modality to probe nanoparticle-targeted abnormalities in real time at cellular and molecular levels. However, detecting rare cell types in a heterogeneous background with strong optical scattering and absorption remains a big challenge. For example, differentiating circulating tumor cells in vivo (typically fewer than 10 cells/mL for an active tumor) among billions of erythrocytes in the blood is nearly impossible. In this paper, a newly developed technique, magnetomotive photoacoustic (mmPA) imaging, which can greatly increase the sensitivity and specificity of sensing targeted cells or molecular interactions, is reviewed. Its primary advantage is suppression of background signals through magnetic enrichment/manipulation with simultaneous PA detection of magnetic contrast agent targeted objects. Results from phantom and in vitro studies demonstrate the capability of mmPA imaging to differentiate regions targeted with magnetic nanoparticles from the background, and to trap and sensitively detect targeted cells at a concentration of a single cell per milliliter in a flow system mimicking a human peripheral artery. This technique provides an example of the ways in which molecular imaging can potentially enable robust molecular diagnosis and treatment, and accelerate the translation of molecular medicine into the clinic.
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Affiliation(s)
- Matthew O'Donnell
- Department of Bioengineering, University of Washington, 3720, 15th Ave NE, Seattle, WA, 98195, USA,
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18
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Hu X, Wei CW, Xia J, Pelivanov I, O'Donnell M, Gao X. Trapping and photoacoustic detection of CTCs at the single cell per milliliter level with magneto-optical coupled nanoparticles. Small 2013; 9:2046-2045. [PMID: 23203788 PMCID: PMC3697911 DOI: 10.1002/smll.201202085] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 10/25/2012] [Indexed: 05/18/2023]
Affiliation(s)
- Xiaoge Hu
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
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19
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Wei CW, Xia J, Pelivanov I, Hu X, Gao X, O'Donnell M. Trapping and dynamic manipulation of polystyrene beads mimicking circulating tumor cells using targeted magnetic/photoacoustic contrast agents. J Biomed Opt 2012; 17:101517. [PMID: 23223993 PMCID: PMC3418505 DOI: 10.1117/1.jbo.17.10.101517] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 06/30/2012] [Accepted: 07/10/2012] [Indexed: 05/18/2023]
Abstract
Results on magnetically trapping and manipulating micro-scale beads circulating in a flow field mimicking metastatic cancer cells in human peripheral vessels are presented. Composite contrast agents combining magneto-sensitive nanospheres and highly optical absorptive gold nanorods were conjugated to micro-scale polystyrene beads. To efficiently trap the targeted objects in a fast stream, a dual magnet system consisting of two flat magnets to magnetize (polarize) the contrast agent and an array of cone magnets producing a sharp gradient field to trap the magnetized contrast agent was designed and constructed. A water-ink solution with an optical absorption coefficient of 10 cm⁻¹ was used to mimic the optical absorption of blood. Magnetomotive photoacoustic imaging helped visualize bead trapping, dynamic manipulation of trapped beads in a flow field, and the subtraction of stationary background signals insensitive to the magnetic field. The results show that trafficking micro-scale objects can be effectively trapped in a stream with a flow rate up to 12 ml/min and the background can be significantly (greater than 15 dB) suppressed. It makes the proposed method very promising for sensitive detection of rare circulating tumor cells within high flow vessels with a highly absorptive optical background.
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Affiliation(s)
- Chen-Wei Wei
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, Washington, USA.
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20
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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. J Biomed Opt 2010; 15:016010. [PMID: 20210456 DOI: 10.1117/1.3292574] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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21
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Abstract
Contrast in photoacoustic imaging is primarily determined by optical absorption. This paper proposes a subband imaging method to further enhance the image contrast. The method is based on media with different absorptions generating acoustic waves with different frequency contents. Generally, assuming all other conditions remain the same, a high-absorption medium generates acoustic waves with higher frequency components, and hence the imaging contrast can be enhanced by appropriate selection of the spectral subbands. This study employed both finite-difference, time-domain-based simulations and phantom imaging. The numerical results show that the peak frequencies of the signals for objects with absorption coefficients of 1 and 100 cmM(-1) were 2.4 and 7.8 MHz, respectively. Imaging an agar-based phantom further demonstrated that the contrast between two objects with absorption coefficients of 5.01 and 41.75 cm(-1) can be improved by 4-10 dB when the frequency band was changed from 0-7 to 7-14 MHz. Finally, a method to further enhance the contrast based on optimal weighting is also presented. The proposed method is of particular interest in photoacoustic molecular imaging.
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Affiliation(s)
- Pai-Chi Li
- Graduate Institute of Biomedical Electronics and Bioinformatics, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan.
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22
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Li PC, Wang CRC, Shieh DB, Wei CW, Liao CK, Poe C, Jhan S, Ding AA, Wu YN. In vivo photoacoustic molecular imaging with simultaneous multiple selective targeting using antibody-conjugated gold nanorods. Opt Express 2008; 16:18605-15. [PMID: 19581946 DOI: 10.1364/oe.16.018605] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The use of gold nanorods for photoacoustic molecular imaging with simultaneous multiple targeting is reported. Multiple targeting is done by utilizing the tunable optical absorption property of gold nanorods. This technique allows multiple molecular signatures to be obtained by simply switching laser wavelength. HER2 and EGFR were chosen as the primary target molecules for examining two cancer cells, OECM1 and Cal27. Both in vitro and in vivo mouse model imaging experiments were performed, with contrast enhancement of up to 10 dB and 3.5 dB, respectively. The potential in improving cancer diagnosis is demonstrated.
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Affiliation(s)
- Pai-Chi Li
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.
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23
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Liu JH, Wei CW, Sheu YL, Tasi YT, Wang YH, Li PC. Design, fabrication and testing of a dual-band photoacoustic transducer. Ultrason Imaging 2008; 30:217-227. [PMID: 19507675 DOI: 10.1177/016173460803000403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Combining photoacoustic and ultrasonic imaging allows both optical and acoustic properties to be displayed simultaneously. In this paper, we describe a dual-band transducer for implementing such a multimodality imaging setup. The transducer exhibits two frequency bands so that it matches the frequency of interest in both imaging methods. An optical fiber is included in the center so that it is inherently coregistered. The transducer was fabricated from lithium niobate and comprises two concentric rings whose center frequencies are 4.9 MHz and 14.8 MHz. Pulse-echo measurements and phantom imaging were performed to demonstrate its performance characteristics.
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Affiliation(s)
- Jian-Hung Liu
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
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24
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Yang CY, Wei CW, Lin YP, Tseng HC, Wu YN, Chen CC, Shieh DB, Li PC. Applications of Carbohydrate-Gold Nanoparticles for Volumetric Flow Measurements Using an Opto-Acoustic Technique. J CHIN CHEM SOC-TAIP 2008. [DOI: 10.1002/jccs.200800016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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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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26
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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 Trans Ultrason Ferroelectr Freq 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] [What about the content of this article? (0)] [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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27
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Wei CW, Huang SW, Wang CRC, Li PC. Photoacoustic flow measurements based on wash-in analysis of gold nanorods. IEEE Trans Ultrason Ferroelectr Freq 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] [What about the content of this article? (0)] [Affiliation(s)] [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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28
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Wei CW, Liao CK, Tseng HC, Lin YP, Chen CC, Li PC. Photoacoustic flow measurements with gold nanoparticles. IEEE Trans Ultrason Ferroelectr Freq Control 2006; 53:1955-9. [PMID: 17036804 DOI: 10.1109/tuffc.2006.128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The hypothesis that quantitative blood flow measurements are feasible with the time-intensity based method in photoacoustic imaging using gold nanoparticles as contrast agent is experimentally tested. The in vitro results show good linearity between the measurements and the theory, thus suggesting the potential of relative photoacoustic flow measurements with gold nanoparticles.
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29
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Li PC, Huang SW, Wei CW, Chiou YC, Chen CD, Wang CRC. Photoacoustic flow measurements by use of laser-induced shape transitions of gold nanorods. Opt Lett 2005; 30:3341-3. [PMID: 16389825 DOI: 10.1364/ol.30.003341] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A quantitative technique for flow measurements based on a wash-in analysis is proposed. The technique makes use of the shape dependence of the optical absorption of gold nanorods and the transitions in their shape induced by pulsed laser irradiation. The photon-induced shape transition of gold nanorods involves mainly a rod-to-sphere conversion and a shift in the peak optical absorption wavelength. The application of a series of laser pulses will induce shape changes in gold nanorods as they flow through a region of interest, with quantitative flow information being derived from the photoacoustic signals from the irradiated gold nanorods measured as a function of time. To demonstrate the feasibility of the technique, a Nd:YAG laser operating at 1064 nm was used for irradiation and a 1 MHz ultrasonic transducer was used for acoustic detection. The flow velocity ranged from 0.35 to 2.83 mm/s. Excellent agreement between the measured velocities and the actual velocities was demonstrated, with a linear regression correlation coefficient of 0.93. This study is a pioneer work on wash-in flow estimation in photoacoustic imaging.
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Affiliation(s)
- Pai-Chi Li
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan.
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30
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Huang DH, Liao CK, Wei CW, Li PC. Simulations of optoacoustic wave propagation in light-absorbing media using a finite-difference time-domain method. J Acoust Soc Am 2005; 117:2795-801. [PMID: 15957750 DOI: 10.1121/1.1893305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Optoacoustic (OA) imaging is an emerging technology that combines the high optical contrast of tissues with the high spatial resolution of ultrasound. Taking full advantage of OA imaging requires a better understanding of OA wave propagation in light-absorbing media. Current simulation methods are mainly based on simplified conditions such as thermal confinement, negligible viscosity, and homogeneous acoustic properties throughout the image object. In this study a new numerical approach is proposed based on a finite-difference time-domain (FDTD) method to solve the general OA equations, comprising the continuity, Navier-Stokes, and heat-conduction equations. The FDTD code was validated using a benchmark problem that has an approximate analytical solution. OA experiments were also conducted and data were in good agreement with those predicted by the FDTD method. Characteristics of simulated OA waveforms and OA images were discussed. The simulator was also employed to study wavefront distortion in OA breast imaging.
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Affiliation(s)
- Deng-Huei Huang
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
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31
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Liao YD, Huang HC, Leu YJ, Wei CW, Tang PC, Wang SC. Purification and cloning of cytotoxic ribonucleases from Rana catesbeiana (bullfrog). Nucleic Acids Res 2000; 28:4097-104. [PMID: 11058105 PMCID: PMC113159 DOI: 10.1093/nar/28.21.4097] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2000] [Revised: 09/20/2000] [Accepted: 09/20/2000] [Indexed: 11/14/2022] Open
Abstract
Ribonucleases with antitumor activity are mainly found in the oocytes and embryos of frogs, but the role of these ribonucleases in frog development is not clear. Moreover, most frog ribonuclease genes have not been cloned and characterized. In the present study, a group of ribonucleases were isolated from Rana catesbeiana (bullfrog). These ribonucleases in mature oocytes, namely RC-RNase, RC-RNase 2, RC-RNase 3, RC-RNase 4, RC-RNase 5 and RC-RNase 6, as well as liver-specific ribonuclease RC-RNase L1, were purified by column chromatographs and detected by zymogram assay and western blotting. Characterization of these purified ribonucleases revealed that they were highly conserved in amino acid sequence and had a pyroglutamate residue at their N-termini, but possessed different specific activities, base specificities and optimal pH values for their activities. These ribonucleases were cytotoxic to cervical carcinoma HeLa cells, but their cytotoxicities were not closely correlated to their enzymatic specific activities. Some other amino acid residues in addition to their catalytic residues were implicated to be involved in the cytotoxicity of the frog ribonucleases to tumor cells. Because the coding regions lack introns, the ribonuclease genes were cloned by PCR using genomic DNA as template. Their DNA sequences and amino acid sequences are homologous to those of mammalian ribonuclease superfamily, approximately 50 and approximately 25%, respectively.
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Affiliation(s)
- Y D Liao
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, Institute of Biochemistry, College of Medicine, National Taiwan University, Taipei 100, Taiwan.
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32
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Yong G, Li YC, Kong XJ, Wei CW. Quantum magnetotransport of electrons in double-barrier resonant-tunneling structures. Phys Rev B Condens Matter 1994; 50:17249-17255. [PMID: 9976126 DOI: 10.1103/physrevb.50.17249] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Stathopoulos VM, Coco-Maroney A, Wei CW, Goth M, Zaricznyj C, Macara IG. Identification of two cytosolic diacylglycerol kinase isoforms in rat brain, and in NIH-3T3 and ras-transformed fibroblasts. Biochem J 1990; 272:569-75. [PMID: 2176468 PMCID: PMC1149746 DOI: 10.1042/bj2720569] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Two major species of diacylglycerol kinase (type I and type II) were separated from brain cytosol and from NIH-3T3 or ras-transformed 3T3 cells by heparin-agarose chromatography. Multiple species of diacylglycerol kinase were also detected by non-denaturing isoelectric focusing. The two peaks of activity were of similar size, both co-eluted at approximately 95 kDa from a Superose f.p.l.c. column. Type II enzyme (pI 8.0) was more active when substrate was presented in a deoxycholate/phosphatidylserine undefined environment, as opposed to an octyl glucoside/phosphatidylserine micellar environment. Type II activity was also enhanced by the presence of phosphatidylcholine as cofactor. Type I enzyme (pI 4.0) was more active in the presence of either phosphatidylserine or phosphatidylinositol. Type I and II enzymes had different ATP affinities. Both enzymes showed a preference for diacylglycerol substrates with saturated acyl chains of 10-12 carbon atoms. The cytosolic enzyme activity was able to bind to diacylglycerol-enriched membranes in NIH-3T3 fibroblasts, and this translocation was unaffected in ras-transformed 3T3 cells. These results demonstrate the presence of multiple diacylglycerol kinases in brain cytosol and NIH-3T3 and ras-transformed 3T3 cells. The enzymes differ in cofactor, ATP and substrate requirements. These results can explain some of the contradictions between previous studies of cytosolic diacylglycerol kinase activity, and suggest the presence of a family of such kinases that are differentially regulated by phospholipid cofactors.
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Affiliation(s)
- V M Stathopoulos
- Environmental Health Sciences Center, University of Rochester School of Medicine and Dentistry, NY 14642
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34
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Kong XJ, Wei CW, Gu SW. Cyclotron resonance of a magnetopolaron in a semiconductor quantum well. Phys Rev B Condens Matter 1989; 39:3230-3238. [PMID: 9948623 DOI: 10.1103/physrevb.39.3230] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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35
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Wei CW, Kong XJ, Gu SW. Cyclotron resonance of an interface polaron in polar-polar crystals. Phys Rev B Condens Matter 1988; 38:8390-8396. [PMID: 9945597 DOI: 10.1103/physrevb.38.8390] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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36
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Wei CW. [Antifertility effects of ilex cornura Lindl]. Zhong Yao Tong Bao 1988; 13:48-50, 64. [PMID: 3197213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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37
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38
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Gu SW, Kong XJ, Wei CW. Properties of a magnetopolaron at the interface of polar-polar crystals. Phys Rev B Condens Matter 1987; 36:7977-7983. [PMID: 9942596 DOI: 10.1103/physrevb.36.7977] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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