51
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Almutairi A, Akers WJ, Berezin MY, Achilefu S, Fréchet JMJ. Monitoring the Biodegradation of Dendritic Near-Infrared Nanoprobes by in Vivo Fluorescence Imaging. Mol Pharm 2008; 5:1103-10. [DOI: 10.1021/mp8000952] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adah Almutairi
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Walter J. Akers
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Mikhail Y. Berezin
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Samuel Achilefu
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Jean M. J. Fréchet
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
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52
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Abstract
Despite technical advances in many areas of diagnostic radiology, the detection and imaging of human cancer remains poor. A meaningful impact on cancer screening, staging, and treatment is unlikely to occur until the tumor-to-background ratio improves by three to four orders of magnitude (ie, 10(3)- to 10(4)-fold), which in turn will require proportional improvements in sensitivity and contrast agent targeting. This review analyzes the physics and chemistry of cancer imaging and highlights the fundamental principles underlying the detection of malignant cells within a background of normal cells. The use of various contrast agents and radiotracers for cancer imaging is reviewed, as are the current limitations of ultrasound, x-ray imaging, magnetic resonance imaging (MRI), single-photon emission computed tomography, positron emission tomography (PET), and optical imaging. Innovative technologies are emerging that hold great promise for patients, such as positron emission mammography of the breast and spectroscopy-enhanced colonoscopy for cancer screening, hyperpolarization MRI and time-of-flight PET for staging, and ion beam-induced PET scanning and near-infrared fluorescence-guided surgery for cancer treatment. This review explores these emerging technologies and considers their potential impact on clinical care. Finally, those cancers that are currently difficult to image and quantify, such as ovarian cancer and acute leukemia, are discussed.
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Affiliation(s)
- John V Frangioni
- Beth Israel Deaconess Medical Center, 330 Brookline Ave, Rm SL-B05, Boston, MA 02215, USA.
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53
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Akers WJ, Berezin MY, Lee H, Achilefu S. Predicting in vivo fluorescence lifetime behavior of near-infrared fluorescent contrast agents using in vitro measurements. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:054042. [PMID: 19021422 PMCID: PMC2744956 DOI: 10.1117/1.2982535] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fluorescence lifetime (FLT) information is complementary to intensity measurement and can be used to improve signal-to-background contrast and provide environment sensing capability. In this study, we evaluate the FLTs of eight near-infrared fluorescent molecular probes in vitro in various solvent mediums and in vivo to establish the correlation between the in vitro and in vivo results. Compared with other mediums, two exponential fittings of the fluorescence decays of dyes dissolved in aqueous albumin solutions accurately predict the range of FLTs observed in vivo. We further demonstrate that the diffusion of a near-infrared (NIR) reporter from a dye-loaded gel can be detected by FLT change in mice as a model of controlled drug release. The mean FLT of the NIR probe increases as the dye diffuses from the highly polar gel interior to the more lipophilic tissue environment. The two-point analysis demonstrates an efficient in vitro method for screening new NIR fluorescent reporters for use as FLT probes in vivo, thereby minimizing the use of animals for FLT screening studies.
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Affiliation(s)
| | | | | | - Samuel Achilefu
- Address Correspondence to: Samuel Achilefu, PhD, Optical Radiology Lab, 4525 Scott Avenue, St. Louis, MO 63110, Telephone: 314-362-8599, Fax: 314-747-5191,
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54
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Liebert A, Wabnitz H, Zołek N, Macdonald R. Monte Carlo algorithm for efficient simulation of time-resolved fluorescence in layered turbid media. OPTICS EXPRESS 2008; 16:13188-202. [PMID: 18711557 DOI: 10.1364/oe.16.013188] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We present an efficient Monte Carlo algorithm for simulation of time-resolved fluorescence in a layered turbid medium. It is based on the propagation of excitation and fluorescence photon bundles and the assumption of equal reduced scattering coefficients at the excitation and emission wavelengths. In addition to distributions of times of arrival of fluorescence photons at the detector, 3-D spatial generation probabilities were calculated. The algorithm was validated by comparison with the analytical solution of the diffusion equation for time-resolved fluorescence from a homogeneous semi-infinite turbid medium. It was applied to a two-layered model mimicking intra- and extracerebral compartments of the adult human head.
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Affiliation(s)
- A Liebert
- Institute of Biocybernetics and Biomedical Engineering, Trojdena 4, 02-109 Warsaw, Poland.
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55
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Smith NI, Kumamoto Y, Iwanaga S, Ando J, Fujita K, Kawata S. A femtosecond laser pacemaker for heart muscle cells. OPTICS EXPRESS 2008; 16:8604-16. [PMID: 18545573 DOI: 10.1364/oe.16.008604] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The intracellular effects of focused near-infrared femtosecond laser irradiation are shown to cause contraction in cultured neonatal rat cardiomyocytes. By periodic exposure to femtosecond laser pulse-trains, periodic contraction cycles in cardiomyocytes could be triggered, depleted, and synchronized with the laser periodicity. This was observed in isolated cells, and in small groups of cardiomyocytes with the laser acting as pacemaker for the entire group. A window for this effect was found to occur between 15 and 30 mW average power for an 80 fs, 82 MHz pulse train of 780 nm, using 8 ms exposures applied periodically at 1 to 2 Hz. At power levels below this power window, laser-induced cardiomyocyte contraction was not observed, while above this power window, cells typically responded by a high calcium elevation and contracted without subsequent relaxation. This laser-cell interaction allows the laser irradiation to act as a pacemaker, and can be used to trigger contraction in dormant cells as well as synchronize or destabilize contraction in spontaneously contracting cardiomyocytes. By increasing laser power above the window available for laser-cell synchronization, we also demonstrate the use of cardiomyocytes as optically-triggered actuators. To our knowledge, this is the first demonstration of remote optical control of cardiomyocytes without requiring exogenous photosensitive compounds.
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Affiliation(s)
- N I Smith
- Department of Frontier Biosciences, Graduate School of Frontier Biosciences Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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56
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Kang M, Shen NH, Chen J, Chen J, Fan YX, Ding J, Wang HT, Wu P. A new planar left-handed metamaterial composed of metal-dielectric-metal structure. OPTICS EXPRESS 2008; 16:8617-8622. [PMID: 18545574 DOI: 10.1364/oe.16.008617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
An improved planar structure of left-handed (LH) metamaterial is presented, and then designed and analyzed in microwave regime. In the anticipated LH frequency regime, the LH property is validated from the phenomena of backward wave propagation and negative refraction. To characterize the electromagnetic property of the planar metamaterial, we introduce the wedge method by constructing a wedge-shaped bulk LH metamaterial by stacking the planar LH metamaterials. The effective refractive index estimated by the wedge method is in excellent agreement with that retrieved by the inversion method from the transmission and reflection spectra.
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Affiliation(s)
- Ming Kang
- 1National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
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57
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Belhadj N, Park Y, Larochelle S, Dossou K, Azaña J. UV-induced modification of stress distribution in optical fibers and its contribution to Bragg grating birefringence. OPTICS EXPRESS 2008; 16:8727-8741. [PMID: 18545586 DOI: 10.1364/oe.16.008727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This paper discusses the importance of stress-induced contributions to the photo-induced birefringence observed in fiber Bragg gratings. Optical tomography measurements are performed in exposed and unexposed fibers to extract the stress profiles induced by UV-writing of fiber Bragg gratings for various exposure levels. A photoelastic analysis and a high-order isoparametric finite elements method are then used to calculate the birefringence caused by stress profile modifications. The results are compared to the birefringence directly measured by spectral analysis of a chirped fiber grating with multiple phase-shifts. We can therefore estimate the fraction of the photo-induced birefringence due to stress-induced anisotropy following UV exposure.
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Affiliation(s)
- N Belhadj
- Centre d'optique, photonique et laser (COPL), Département de génie électrique et de génie informatique, Université Laval, Québec (Québec) Canada
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58
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Rodriguez FJ, Wang FX, Kauranen M. Calibration of the second-order nonlinear optical susceptibility of surface and bulk of glass. OPTICS EXPRESS 2008; 16:8704-8710. [PMID: 18545583 DOI: 10.1364/oe.16.008704] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A two-beam second-harmonic generation technique is developed to calibrate the magnitude of the second-order nonlinear optical susceptibility components of surface and bulk (multipolar origin) of isotropic materials. The values obtained for fused silica calibrated against ChiXXX of crystalline quartz are chi parallel parallel perpendicular = 7.9(4), chi perpendicular parallel parallel (+)gamma = 3.8(4), parallel perpendicular perpendicular perpendicular(+)gamma = 59(4), and delta' = 7.8(4) in units of 10(-22) m(2)/V. Similar values are obtained for BK7 glass. An alternative way of calibration against ChiXYZ of quartz is demonstrated. The technique could also be extended to characterize the susceptibility tensor of crystals as a convenient alternative to the Maker-fringe technique.
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Affiliation(s)
- Francisco J Rodriguez
- Department of Physics,Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland.
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59
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Philippe S, Bradley AL, Maldonado-Basilio R, Surre F, Kennedy BF, Landais P, Soto-Ortiz H. Polarization dependence of non-linear gain compression factor in semiconductor optical amplifier. OPTICS EXPRESS 2008; 16:8641-8648. [PMID: 18545577 DOI: 10.1364/oe.16.008641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We investigate the power and the polarization dependence of the intraband dynamics in a bulk semiconductor optical amplifier using both a 2.5-ps pump-probe experimental set-up in contra-propagation and a theoretical model. Our model is based on the rate equations and takes into account the polarization dependence of the gain. By comparing experimental and computational results we are able to highlight the dependences of the intraband dynamics and to extract the non-linear gain compression factor as a function of both pulse energy and polarization of the injected pulses.
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60
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Yazdanfar S, Kenny KB, Tasimi K, Corwin AD, Dixon EL, Filkins RJ. Simple and robust image-based autofocusing for digital microscopy. OPTICS EXPRESS 2008; 16:8670-7. [PMID: 18545580 DOI: 10.1364/oe.16.008670] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A simple image-based autofocusing scheme for digital microscopy is demonstrated that uses as few as two intermediate images to bring the sample into focus. The algorithm is adapted to a commercial inverted microscope and used to automate brightfield and fluorescence imaging of histopathology tissue sections.
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Affiliation(s)
- Siavash Yazdanfar
- GE Global Research, One Research Circle, Niskayuna, N.Y. 12309, USA.
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61
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Xu F, Poon AW. Silicon cross-connect filters using microring resonator coupled multimode-interference-based waveguide crossings. OPTICS EXPRESS 2008; 16:8649-8657. [PMID: 18545578 DOI: 10.1364/oe.16.008649] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report silicon cross-connect filters using microring resonator coupled multimode-interference (MMI) based waveguide crossings. Our experiments reveal that the MMI-based cross-connect filters impose lower crosstalk at the crossing than the conventional cross-connect filters using plain crossings, while offering a nearly symmetric resonance line shape in the drop-port transmission. As a proof-of-concept for cross-connection applications, we demonstrate on a silicon-on-insulator substrate (i) a 4-channel 1 x 4 linear-cascaded MMI-based cross-connect filter, and (ii) a 2-channel 2 x 2 array-cascaded MMI-based cross-connect filter.
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Affiliation(s)
- Fang Xu
- Photonic Device Laboratory, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China
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62
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Heilmann RK, Ahn M, Gullikson EM, Schattenburg ML. Blazed high-efficiency x-ray diffraction via transmission through arrays of nanometer-scale mirrors. OPTICS EXPRESS 2008; 16:8658-8669. [PMID: 18545579 DOI: 10.1364/oe.16.008658] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Diffraction gratings are ubiquitous wavelength dispersive elements for photons as well as for subatomic particles, atoms, and large molecules. They serve as enabling devices for spectroscopy, microscopy, and interferometry in numerous applications across the physical sciences. Transmission gratings are required in applications that demand high alignment and figure error tolerances, low weight and size, or a straight-through zero-order beam. However, photons or particles are often strongly absorbed upon transmission, e.g., in the increasingly important extreme ultraviolet (EUV) and soft x-ray band, leading to low diffraction efficiency. We demonstrate the performance of a critical-angle transmission (CAT) grating in the EUV and soft x-ray band that for the first time combines the advantages of transmission gratings with the superior broadband efficiency of blazed reflection gratings via reflection from nanofabricated periodic arrays of atomically smooth nanometer-thin silicon mirrors at angles below the critical angle for total external reflection. The efficiency of the CAT grating design is not limited to photons, but also opens the door to new, sensitive, and compact experiments and applications in atom and neutron optics, as well as for the efficient diffraction of electrons, ions, or molecules.
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Affiliation(s)
- Ralf K Heilmann
- 1Space Nanotechnology Laboratory, MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02026, USA.
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63
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Yoo HG, Fu Y, Riley D, Shin JH, Fauchet PM. Birefringence and optical power confinement in horizontal multi-slot waveguides made of Si and SiO2. OPTICS EXPRESS 2008; 16:8623-8628. [PMID: 18545575 DOI: 10.1364/oe.16.008623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Through simulations and measurements, we show that in multi-slot thin film waveguides, the TM polarized modes can be confined mostly in the low refractive index layers of the waveguide. The structure consisted of alternating layers of a-Si and SiO(2), in the thickness range between 3 and 40 nm, for which the slots were the SiO(2) layers. Simulations were performed using the transfer matrix method and experiments using the m-line technique at 1.55 mum. The dependence of the birefringence and of the power confinement in the slots was studied as a function of the waveguide thickness, the Si and SiO(2) layer thicknesses, and the SiO(2) / Si layer thickness ratio. We find a large birefringence-a refractive index difference between TE and TM modes-as large as 0.8. For TM polarized modes, up to ~ 85% of the total power in the fundamental mode can be confined in the slots.
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Affiliation(s)
- Han G Yoo
- Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA.
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64
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Berger JA, Greco MJ, Schroeder WA. High-power, femtosecond, thermal-lens-shaped Yb:KGW oscillator. OPTICS EXPRESS 2008; 16:8629-8640. [PMID: 18545576 DOI: 10.1364/oe.16.008629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Thermal lens shaping for astigmatism compensation is extended to a high-power, diode-pumped, Yb:KGW laser by employing a gain crystal geometry designed for efficient polarized pumping. The 63MHz oscillator is soliton mode-locked with the aid of a saturable Bragg reflector to yield 250fs (347fs) pulses at an output power of 3.5W (5W). Frequency doubling of the 250fs pulses with an intrinsic efficiency >60% provides 1.65W of average green power.
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Affiliation(s)
- Joel A Berger
- Department of Physics (m/c 273), University of Illinois at Chicago, 845 W. Taylor Street (rm. 2236), Chicago, IL 60607-7059, USA.
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65
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Andermahr N, Fallnich C. Interaction of transverse modes in a single-frequency few-mode fiber amplifier caused by local gain saturation. OPTICS EXPRESS 2008; 16:8678-8684. [PMID: 18545581 DOI: 10.1364/oe.16.008678] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report on the behavior of modal polarization states in a single-frequency, ytterbium-doped, few-mode fiber amplifier. Experimental data show that the polarization of the individual transverse modes depends on the pump power and that the modes tend towards orthogonally polarized states with increasing gain. The observations can be explained by local gain saturation that favors the amplification of differently polarized modes.
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Affiliation(s)
- N Andermahr
- Laser Zentrum Hannover, Hollerithallee 8, 30419 Hannover, Germany.
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66
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Wang Q, Yang H, Agrawal A, Wang NS, Pfefer TJ. Measurement of internal tissue optical properties at ultraviolet and visible wavelengths: Development and implementation of a fiberoptic-based system. OPTICS EXPRESS 2008; 16:8685-703. [PMID: 18545582 DOI: 10.1364/oe.16.008685] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A novel, multi-wavelength, fiberoptic system was constructed, evaluated and implemented to determine internal tissue optical properties at ultraviolet A (UVA) and visible (VIS) wavelengths. Inverse modeling was performed with a neural network to estimate absorption and reduced scattering coefficients based on spatially-resolved reflectance distributions. The model was calibrated with simulated reflectance datasets generated using a condensed Monte Carlo approach with absorption coefficients up to 85 cm(-1) and reduced scattering coefficients up to 118 cm(-1). After theoretical and experimental evaluations of the system, optical properties of porcine bladder, colon, esophagus, oral mucosa, and liver were measured at 325, 375, 405, 445 and 532 nm. These data provide evidence that as wavelengths decrease into the UVA, the dominant tissue chromophore shifts from hemoglobin to structural proteins such as collagen. This system provides a high level of accuracy over a wide range of optical properties, and should be particularly useful for in situ characterization of highly attenuating biological tissues in the UVA-VIS.
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Affiliation(s)
- Quanzeng Wang
- Food and Drug Administration, Center for Devices & Radiological Health, Silver Spring, Maryland 20993, USA
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67
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Hakulinen T, Koskinen R, Okhotnikov OG. Low jitter Q-switched fiber laser using optically driven surface-normal saturable absorber modulator. OPTICS EXPRESS 2008; 16:8720-8726. [PMID: 18545585 DOI: 10.1364/oe.16.008720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A technique for stabilizing the repetition frequency of a passively Q-switched laser is presented using an optically driven surface-normal semiconductor modulator. A method is capable of significant reduction of the timing jitter in a passively Q-switched laser by optical triggering the saturable absorber semiconductor reflector. The experimental demonstration using passively Q-switched ytterbium-doped fiber laser shows the jitter reduction by factor of 1.66??10(3) from 50 mus down to 30 ns.
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Affiliation(s)
- Tommi Hakulinen
- Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3, 33720 Tampere.
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68
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Kepshire D, Davis SC, Dehghani H, Paulsen KD, Pogue BW. Fluorescence tomography characterization for sub-surface imaging with protoporphyrin IX. OPTICS EXPRESS 2008; 16:8581-93. [PMID: 18545571 PMCID: PMC2696352 DOI: 10.1364/oe.16.008581] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Optical imaging of fluorescent objects embedded in a tissue simulating medium was characterized using non-contact based approaches to fluorescence remittance imaging (FRI) and sub-surface fluorescence diffuse optical tomography (FDOT). Using Protoporphyrin IX as a fluorescent agent, experiments were performed on tissue phantoms comprised of typical in-vivo tumor to normal tissue contrast ratios, ranging from 3.5:1 up to 10:1. It was found that tomographic imaging was able to recover interior inclusions with high contrast relative to the background; however, simple planar fluorescence imaging provided a superior contrast to noise ratio. Overall, FRI performed optimally when the object was located on or close to the surface and, perhaps most importantly, FDOT was able to recover specific depth information about the location of embedded regions. The results indicate that an optimal system for localizing embedded fluorescent regions should combine fluorescence reflectance imaging for high sensitivity and sub-surface tomography for depth detection, thereby allowing more accurate localization in all three directions within the tissue.
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Affiliation(s)
- Dax Kepshire
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755 USA
- Corresponding author: ,
| | - Scott C. Davis
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755 USA
| | - Hamid Dehghani
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755 USA
- School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Keith D. Paulsen
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755 USA
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755 USA
- Corresponding author: ,
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69
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Asatsuma T, Baba T. Aberration reduction and unique light focusing in a photonic crystal negative refractive lens. OPTICS EXPRESS 2008; 16:8711-8719. [PMID: 18545584 DOI: 10.1364/oe.16.008711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Light focusing characteristics of a negative refractive lens fabricated out of a silicon-on-insulator photonic crystal (PC) slab are investigated theoretically and experimentally. It focuses in the near infrared, but the focal spot is degraded by a lens aberration. To reduce the aberration, we designed a composite PC that gives rise to a narrower focal spot. In addition, two unique functions of this lens are demonstrated: refocusing outside of the PC and parallel focusing, enabling image transfer and real image formation, respectively. These results prove the feasibility of an in-plane free space optical network based on negative refraction.
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Affiliation(s)
- Tomohiko Asatsuma
- Yokohama National University, Department of Electrical and Computer Engineering 79-5 Tokiwadai, Hodogayaku, Yokohama 240-8501, Japan
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70
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Hematoporphyrin-mediated fluorescence reflectance imaging: application to early tumor detection in vivo in small animals. Lasers Med Sci 2008; 24:284-9. [DOI: 10.1007/s10103-007-0523-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Accepted: 10/23/2007] [Indexed: 10/22/2022]
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71
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Wall A, Bremer C. Optical Imaging Techniques for Breast Cancer. Cancer Imaging 2008. [DOI: 10.1016/b978-012374212-4.50060-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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72
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Almutairi A, Guillaudeu SJ, Berezin MY, Achilefu S, Fréchet JMJ. Biodegradable pH-Sensing Dendritic Nanoprobes for Near-Infrared Fluorescence Lifetime and Intensity Imaging. J Am Chem Soc 2007; 130:444-5. [DOI: 10.1021/ja078147e] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adah Almutairi
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Steven J. Guillaudeu
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Mikhail Y. Berezin
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Samuel Achilefu
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Jean M. J. Fréchet
- College of Chemistry, University of California, Berkeley, California 94720-1460, and Department of Radiology, School of Medicine, Washington University, St. Louis, Missouri 63110
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73
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Louis DN. Molecular pathology of malignant gliomas. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2007; 2:277-305. [PMID: 18039109 DOI: 10.1146/annurev.pathol.2.010506.091930] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Malignant gliomas, the most common type of primary brain tumor, are a spectrum of tumors of varying differentiation and malignancy grades. These tumors may arise from neural stem cells and appear to contain tumor stem cells. Early genetic events differ between astrocytic and oligodendroglial tumors, but all tumors have an initially invasive phenotype, which complicates therapy. Progression-associated genetic alterations are common to different tumor types, targeting growth-promoting and cell cycle control pathways and resulting in focal hypoxia, necrosis, and angiogenesis. Knowledge of malignant glioma genetics has already impacted clinical management of these tumors, and researchers hope that further knowledge of the molecular pathology of malignant gliomas will result in novel therapies.
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Affiliation(s)
- David N Louis
- Molecular Pathology Unit, Department of Pathology and Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
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74
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Abstract
Cell-based therapy has been heralded as a promising, novel therapeutic strategy for cardiovascular diseases. Despite a rapid transition from animal studies to clinical trials, there remain numerous unresolved, and at times, controversial issues with respect to underlying molecular mechanisms. In parallel, recent advances in the field of molecular imaging has provided a means to bridge the gap in knowledge through in vivo stem cells tracking. Herein, we review current in vivo imaging techniques and future directions for tracking the effects of cell-based therapy.
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Affiliation(s)
- Kozo Hoshino
- Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
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75
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Akers W, Lesage F, Holten D, Achilefu S. In Vivo Resolution of Multiexponential Decays of Multiple Near-Infrared Molecular Probes by Fluorescence Lifetime-Gated Whole-Body Time-Resolved Diffuse Optical Imaging. Mol Imaging 2007. [DOI: 10.2310/7290.2007.00020] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The biodistribution of two near-infrared fluorescent agents was assessed in vivo by time-resolved diffuse optical imaging. Bacteriochlorophyll a (BC) and cypate-glysine-arginine-aspartic acid-serine-proline-lysine-OH (Cyp-GRD) were administered separately or combined to mice with subcutaneous xenografts of human breast adenocarcinoma and slow-release estradiol pellets for improved tumor growth. The same excitation (780 nm) and emission (830 nm) wavelengths were used to image the distinct fluorescence lifetime distribution of the fluorescent molecular probes in the mouse cancer model. Fluorescence intensity and lifetime maps were reconstructed after raster-scanning whole-body regions of interest by time-correlated single-photon counting. Each captured temporal point-spread function (TPSF) was deconvolved using both a single and a multiexponental decay model to best determine the measured fluorescence lifetimes. The relative signal from each fluorophore was estimated for any region of interest included in the scanned area. Deconvolution of the individual TPSFs from whole-body fluorescence intensity scans provided corresponding lifetime images for comparing individual component biodistribution. In vivo fluorescence lifetimes were determined to be 0.8 ns (Cyp-GRD) and 2 ns (BC). This study demonstrates that the relative biodistribution of individual fluorophores with similar spectral characteristics can be compartmentalized by using the time-domain fluorescence lifetime gating method.
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Affiliation(s)
- Walter Akers
- From the Optical Radiology Lab, Department of Radiology, and Department of Chemistry, Washington University School of Medicine, St. Louis, MO; and the Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, QC
| | - Frederic Lesage
- From the Optical Radiology Lab, Department of Radiology, and Department of Chemistry, Washington University School of Medicine, St. Louis, MO; and the Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, QC
| | - Dewey Holten
- From the Optical Radiology Lab, Department of Radiology, and Department of Chemistry, Washington University School of Medicine, St. Louis, MO; and the Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, QC
| | - Samuel Achilefu
- From the Optical Radiology Lab, Department of Radiology, and Department of Chemistry, Washington University School of Medicine, St. Louis, MO; and the Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, QC
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76
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Gurfinkel M, Thompson AB, Ralston W, Troy TL, Moore AL, Moore TA, Gust JD, Tatman D, Reynolds JS, Muggenburg B, Nikula K, Pandey R, Mayer RH, Hawrysz DJ, Sevick-Muraca EM. Pharmacokinetics of ICG and HPPH-car for the Detection of Normal and Tumor Tissue Using Fluorescence, Near-infrared Reflectance Imaging: A Case Study ¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2000)0720094poiahc2.0.co2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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77
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Houston JP, Thompson AB, Gurfinkel M, Sevick-Muraca EM. Sensitivity and Depth Penetration of Continuous Wave Versus Frequency-domain Photon Migration Near-infrared Fluorescence Contrast-enhanced Imaging ¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2003)0770420sadpoc2.0.co2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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78
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Licha K, Riefke B, Ntziachristos V, Becker A, Chance B, Semmler W. Hydrophilic Cyanine Dyes as Contrast Agents for Near-infrared Tumor Imaging: Synthesis, Photophysical Properties and Spectroscopic In vivo Characterization ¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2000)0720392hcdaca2.0.co2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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79
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Kepshire DS, Davis SC, Dehghani H, Paulsen KD, Pogue BW. Subsurface diffuse optical tomography can localize absorber and fluorescent objects but recovered image sensitivity is nonlinear with depth. APPLIED OPTICS 2007; 46:1669-78. [PMID: 17356609 DOI: 10.1364/ao.46.001669] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Subsurface tomography with diffuse light has been investigated with a noncontact approach to characterize the performance of absorption and fluorescence imaging. Using both simulations and experiments, the reconstruction of local subsurface heterogeneity is demonstrated, but the recovery of target size and fluorophore concentration is not linear when changes in depth occur, whereas the mean position of the object for experimental fluorescent and absorber targets is accurate to within 0.5 and 1.45 mm when located within the first 10 mm below the surface. Improvements in the linearity of the response with depth appear to remain challenging and may ultimately limit the approach to detection rather than characterization applications. However, increases in tissue curvature and/or the addition of prior information are expected to improve the linearity of the response. The potential for this type of imaging technique to serve as a surgical guide is highlighted.
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Affiliation(s)
- Dax S Kepshire
- Thayer School of Engineering, Dartmouth College, New Hampshire 03755, USA.
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80
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Abstract
Visible light and near infrared light interact with biological tissue by absorption and scattering. Diffuse optical imaging and spectroscopy reconstructs tissue physiologic parameters based on noninvasive measurement of tissue optical properties. This technology can be used to differentiate physiologic and molecular signatures of both malignant and benign tissues, as they relate to the area of cancer research. Major advantages are the use of non-ionizing radiation, real-time continuous data acquisition, low cost, and portability. Limitations include low spatial resolution and limited reproducibility. This paper reviews the currently available state-of-the-art technologies for diffuse optical imaging and spectroscopy and their applications in cancer research.
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Affiliation(s)
- Ronald X Xu
- The Ohio State University, Assistant Professor, Department of Biomedical Engineering, 270 Bevis Hall, 1080 Carmack Road, Columbus, OH 43210, USA.
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81
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Sharma R, Wang W, Rasmussen JC, Joshi A, Houston JP, Adams KE, Cameron A, Ke S, Kwon S, Mawad ME, Sevick-Muraca EM. Quantitative imaging of lymph function. Am J Physiol Heart Circ Physiol 2007; 292:H3109-18. [PMID: 17307997 DOI: 10.1152/ajpheart.01223.2006] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Functional lymphatic imaging was demonstrated in the abdomen and anterior hindlimb of anesthetized, intact Yorkshire swine by using near-infrared (NIR) fluorescence imaging following intradermal administration of 100-200 microl of 32 microM indocyanine green (ICG) and 64 microM hyaluronan NIR imaging conjugate to target the lymph vascular endothelial receptor (LYVE)-1 on the lymph endothelium. NIR fluorescence imaging employed illumination of 780 nm excitation light ( approximately 2 mW/cm(2)) and collection of 830 nm fluorescence generated from the imaging agents. Our results show the ability to image the immediate trafficking of ICG from the plexus, through the vessels and lymphangions, and to the superficial mammary, subiliac, and middle iliac lymph nodes, which were located as deep as 3 cm beneath the tissue surface. "Packets" of ICG-transited lymph vessels of 2-16 cm length propelled at frequencies of 0.5-3.3 pulses/min and velocities of 0.23-0.75 cm/s. Lymph propulsion was independent of respiration rate. In the case of the hyaluronan imaging agent, lymph propulsion was absent as the dye progressed immediately through the plexus and stained the lymph vessels and nodes. Lymph imaging required 5.0 and 11.9 microg of ICG and hyaluronan conjugate, respectively. Our results suggest that microgram quantities of NIR optical imaging agents and their conjugates have a potential to image lymph function in patients suffering from lymph-related disorders.
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Affiliation(s)
- Ruchi Sharma
- Division of Molecular Imaging, Department of Radiology, Baylor College of Medicine, Houston, TX 77030, USA
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82
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Contag CH. Molecular imaging using visible light to reveal biological changes in the brain. Neuroimaging Clin N Am 2007; 16:633-54, ix. [PMID: 17148024 DOI: 10.1016/j.nic.2006.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Advances in imaging have enabled the study of cellular and molecular processes in the context of the living body that include cell migration patterns, location and extent of gene expression, degree of protein-protein interaction, and levels of enzyme activity. These tools, which operate over a range of scales, resolutions, and sensitivities, have opened up broad new areas of investigation where the influence of organ systems and functional circulation is intact. There are a myriad of imaging modalities available, each with its own advantages and disadvantages, depending on the specific application. Among these modalities, optical imaging techniques, including in vivo bioluminescence imaging and fluorescence imaging, use visible light to interrogate biology in the living body. Optimal imaging with these modalities require that the appropriate marker be used to tag the process of interest to make it uniquely visible using a particular imaging technology. For each optical modality, there are various labels to choose from that range from dyes that permit tissue contrast and dyes that can be activated by enzymatic activity, to gene-encoding proteins with optical signatures that can be engineered into specific biological processes. This article provides and overview of optical imaging technologies and commonly used labels, focusing on bioluminescence and fluorescence, and describes several examples of how these tools are applied to biological questions relating to the central nervous system.
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Affiliation(s)
- Christopher H Contag
- Departments of Pediatrics, Microbiology & Immunology and Radiology, E150 Clark Center, MC 5427, Stanford University School of Medicine, Stanford, CA 94305, USA.
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83
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Abstract
There is a wealth of new fluorescent reporter technologies for tagging of many cellular and subcellular processes in vivo. This imposed contrast is now captured with an increasing number of available imaging methods that offer new ways to visualize and quantify fluorescent markers distributed in tissues. This is an evolving field of imaging sciences that has already achieved major advances but is also facing important challenges. It is nevertheless well poised to significantly impact the ways of biological research, drug discovery, and clinical practice in the years to come. Herein, the most pertinent technologies associated with in vivo noninvasive or minimally invasive fluorescence imaging of tissues are summarized. Focus is given to small-animal imaging. However, while a broad spectrum of fluorescence reporter technologies and imaging methods are outlined, as necessary for biomedical research, and clinical translation as well.
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Affiliation(s)
- Vasilis Ntziachristos
- Laboratory for Bio-Optics and Molecular Imaging, Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
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84
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Wu Y, Cai W, Chen X. Near-infrared fluorescence imaging of tumor integrin alpha v beta 3 expression with Cy7-labeled RGD multimers. Mol Imaging Biol 2006; 8:226-36. [PMID: 16791749 PMCID: PMC1643841 DOI: 10.1007/s11307-006-0041-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE Cell adhesion molecule integrin alpha v beta 3 is an excellent target for tumor interventions because of its unique expression on the surface of several types of solid tumor cells and on almost all sprouting tumor vasculatures. Here, we describe the development of near-infrared (NIR) fluorochrome Cy7-labeled RGD peptides for tumor integrin targeting. PROCEDURES Mono-, di-, and tetrameric RGD peptides were synthesized and conjugated with Cy7. The integrin specificity of these fluorescent probes was tested in vitro for receptor binding assay and fluorescence microscopy and in vivo for subcutaneous U87MG tumor targeting. RESULTS The tetrameric RGD peptide probe with the highest integrin affinity showed the highest tumor activity accumulation and strongest tumor-to-normal tissue contrast. This uptake is integrin-specific as the signal accumulated in the tumor can be effectively blocked by unconjugated RGD peptide antagonist of integrin alpha v beta 3. CONCLUSIONS Noninvasive NIR fluorescence imaging is able to detect and semiquantify tumor integrin expression based upon the highly potent tetrameric RGD peptide probe.
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Affiliation(s)
- Yun Wu
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University School of Medicine, 1201 Welch Rd, P095, Stanford, CA 94305-5484, USA
| | - Weibo Cai
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University School of Medicine, 1201 Welch Rd, P095, Stanford, CA 94305-5484, USA
| | - Xiaoyuan Chen
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University School of Medicine, 1201 Welch Rd, P095, Stanford, CA 94305-5484, USA
- Correspondence to: Xiaoyuan Chen; e-mail:
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85
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Liebert A, Wabnitz H, Obrig H, Erdmann R, Möller M, Macdonald R, Rinneberg H, Villringer A, Steinbrink J. Non-invasive detection of fluorescence from exogenous chromophores in the adult human brain. Neuroimage 2006; 31:600-8. [PMID: 16478666 DOI: 10.1016/j.neuroimage.2005.12.046] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 11/24/2005] [Accepted: 12/16/2005] [Indexed: 10/25/2022] Open
Abstract
This is the first report on results proving that fluorescence of exogenous dyes inside the human brain can be excited and detected non-invasively at the surface of the adult head. Boli of indocyanine green (ICG) were intravenously applied to healthy volunteers, and the passage of the contrast agent in the brain was monitored by detecting the corresponding fluorescence signal following pulsed laser excitation at 780 nm. Our hypothesis that the observed fluorescence signal contains a considerable cortical fraction was corroborated by performing measurements with picosecond temporal resolution and analyzing distributions of times of arrival of photons, hence taking advantage of the well-known depth selectivity of that method. Our experimental findings are explained by Monte Carlo simulations modeling the head as a layered medium and taking into account realistic bolus kinetics within the extra- and intracerebral compartment. Although a particular non-specific dye (ICG) was used, the results clearly demonstrate that fluorescence-mediated imaging of the adult human brain is generally feasible. In particular, we will discuss how these results serve as proof of concept for non-invasive fluorescence brain imaging and may thus open the door towards optical molecular imaging of the human brain.
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Affiliation(s)
- A Liebert
- Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany.
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86
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Vera DR, Hall DJ, Hoh CK, Gallant P, McIntosh LM, Mattrey RF. Cy5.5-DTPA-galactosyl-dextran: a fluorescent probe for in vivo measurement of receptor biochemistry. Nucl Med Biol 2006; 32:687-93. [PMID: 16243643 DOI: 10.1016/j.nucmedbio.2005.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2005] [Revised: 04/04/2005] [Accepted: 04/04/2005] [Indexed: 11/29/2022]
Abstract
The high sensitivity of fluorescent reporters offers an opportunity to analytically probe the biochemistry of in vivo receptor systems with low target tissue concentration. We investigated the ability of an optical imaging system to acquire adequate signal for in vivo measurement of receptor biochemistry. The imaging system consisted of a small animal optical imager operating in the time domain (TD) and a fluorescent-labeled diagnostic probe of known receptor-binding properties. Optical imaging of mice (n = 4) using the targeted probe, Cy5.5-DTPA-galactosyl-dextran (2.2 Cy5.5, 4 DTPA, 68 galactose units per dextran, 124 kDa, 24 nmol/kg), demonstrated blood clearance and hepatic uptake. The mean and standard deviation for the time to reach 90% of the peak liver intensity were 15.4 +/- 1.6 min. Typical fluorescent intensities within a 10-pixel region-of-interest from a 30-s image acquired 30 min postinjection were in excess of 2.5 million counts. The nontargeted agent (Cy5.5-DTPA-dextran) did not demonstrate (n = 4) hepatic uptake. This uptake pattern was duplicated by nuclear imaging of rabbits using (99m)Tc-labeled Cy5.5-DTPA-galactosyl-dextran and Cy5.5-DTPA-dextran. This study demonstrated the feasibility of optically labeling a receptor-binding diagnostic probe and imaging in the TD with sufficient sensitivity and temporal resolution for pharmacokinetic analysis.
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Affiliation(s)
- David R Vera
- Department of Radiology, University of California, San Diego, La Jolla, 92093, USA.
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87
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Abstract
Optical imaging is a highly sensitive technique for detecting a variety of cellular, molecular and tissue processes in vivo and in vitro. Optical imaging systems are well suited to in vivo imaging in the laboratory setting for a variety of reasons, including low cost, ease of use and efficiency of imaging. Commercial availability of optical imaging detector systems has allowed more investigators to explore their use for a variety of applications. The ever-increasing number of naturally occurring and modified near-infrared probes, photoproteins, and fluorescent probes provide opportunities to improve detection and labeling. Technical advances in detector systems and imaging software have allowed the refinement of established techniques. Furthermore, the availability of mice genetically altered to express photo and fluorescent proteins have spurred tremendous growth in this area of research.
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Affiliation(s)
- Deborah Citrin
- Imaging and Molecular Theraputics Section, Radiation Oncology and Vascular Biology Faculty, National Cancer Institute, Bethesda, MD USA.
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88
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Hakumäki JM, Liimatainen T. Molecular imaging of apoptosis in cancer. Eur J Radiol 2005; 56:143-53. [PMID: 15885960 DOI: 10.1016/j.ejrad.2005.03.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Revised: 03/05/2005] [Accepted: 03/08/2005] [Indexed: 11/19/2022]
Abstract
Apoptosis plays an important role in cancer. Mechanisms hindering its action are implicated in a number of malignancies. Also, the induction of apoptosis plays a pivotal role in non-surgical cancer treatment regimes such as irradiation, chemotherapy, or hormones. Recent advanced in imaging science have made it now possible for us to detect and visualize previously inaccessible and even unrecognized biological phenomena in cells and tissue undergoing apoptosis in vivo. Not only are these imaging techniques painting an intriguing picture of the spatiotemporal characteristics and metabolic and biophysical of apoptosis in situ, but they are expected to have an ever increasing impact in preclinical testing and design of new anticancer agents as well. Rapid and accurate visualization of apoptotic response in the clinical settings can also be of significant diagnostic and prognostic worth. With the advent of molecular medicine and patient-tailored treatment options and therapeutic agents, such monitoring techniques are becoming paramount.
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Affiliation(s)
- Juhana M Hakumäki
- Cellular and Molecular Imaging Group, Department of Biomedical NMR, A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
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89
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Aina OH, Marik J, Gandour-Edwards R, Lam KS. Near-Infrared Optical Imaging of Ovarian Cancer Xenografts with Novel α3-Integrin Binding Peptide “OA02”. Mol Imaging 2005; 4:439-47. [PMID: 16285906 DOI: 10.2310/7290.2005.05169] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Revised: 06/15/2005] [Accepted: 06/20/2005] [Indexed: 11/18/2022] Open
Abstract
Through screening of random one-bead one-compound (OBOC) libraries, we previously identified cyclic peptides with the cDGXGXXc motif that bind to α3 integrin subunit on ovarian adenocarcinoma cell lines ES-2, SKOV-3, and CaOV-3. We subsequently synthesized two secondary libraries based on this motif and identified new peptides that bound with a higher affinity to these cell lines. One of the peptides identified from the 20% “down-substituted” focused library was the cdG-HCit-GPQc (“OA02”) peptide. The goal of this study was to determine whether this peptide labeled with near-infrared probes could be detected after intravenous injection in ovarian tumor-bearing mice and if it would selectively localize in the tumor. Three different forms of this peptide were synthesized, “OA02”-biotin (noncovalently linked to streptavidin-Cy5.5); “OA02”-Cy5.5 and “OA02”-AlexaFluo 680. Using a KODAK IS2000MM image station, these peptide probes were used at the near-infrared (NIR) spectra to image nude mice bearing ES-2 (α3 integrin positive) and Raji (α3 integrin negative) xenografts. The peptide probe displayed highly specific tumor uptake within 15 min, which lasted for 70 min for “OA02”-Cy5.5 and “OA02”-AlexaFluo 680 and for 24 hours for “OA02”-biotin-streptavidin-Cy5.5. Some kidney and bladder signal were noted. Prior injection with anti-α3 monoclonal antibody blocked the binding of this peptide to the ES-2 tumors.
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90
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Ntziachristos V, Ripoll J, Wang LV, Weissleder R. Looking and listening to light: the evolution of whole-body photonic imaging. Nat Biotechnol 2005; 23:313-20. [PMID: 15765087 DOI: 10.1038/nbt1074] [Citation(s) in RCA: 950] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Optical imaging of live animals has grown into an important tool in biomedical research as advances in photonic technology and reporter strategies have led to widespread exploration of biological processes in vivo. Although much attention has been paid to microscopy, macroscopic imaging has allowed small-animal imaging with larger fields of view (from several millimeters to several centimeters depending on implementation). Photographic methods have been the mainstay for fluorescence and bioluminescence macroscopy in whole animals, but emphasis is shifting to photonic methods that use tomographic principles to noninvasively image optical contrast at depths of several millimeters to centimeters with high sensitivity and sub-millimeter to millimeter resolution. Recent theoretical and instrumentation advances allow the use of large data sets and multiple projections and offer practical systems for quantitative, three-dimensional whole-body images. For photonic imaging to fully realize its potential, however, further progress will be needed in refining optical inversion methods and data acquisition techniques.
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Affiliation(s)
- Vasilis Ntziachristos
- Center for Molecular Imaging Research, Massachusetts General Hospital & Harvard Medical School CNY149, 13th street 5406, Charlestown, Massachusetts 02129, USA.
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91
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Ohnishi S, Lomnes SJ, Laurence RG, Gogbashian A, Mariani G, Frangioni JV. Organic Alternatives to Quantum Dots for Intraoperative Near-Infrared Fluorescent Sentinel Lymph Node Mapping. Mol Imaging 2005; 4:172-81. [PMID: 16194449 DOI: 10.1162/15353500200505127] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 04/18/2005] [Accepted: 04/22/2005] [Indexed: 11/04/2022] Open
Abstract
Intraoperative near-infrared (NIR) fluorescence imaging provides the surgeon with real-time image guidance during cancer and other surgeries. We have previously reported the use of NIR fluorescent quantum dots (QDs) for sentinel lymph node (SLN) mapping. However, because of concerns over potential toxicity, organic alternatives to QDs will be required for initial clinical studies. We describe a family of 800 nm organic heptamethine indocyanine-based contrast agents for SLN mapping spanning a spectrum from 775 Da small molecules to 7 MDa nanocolloids. We provide a detailed characterization of the optical and physical properties of these contrast agents and discuss the advantages and disadvantages of each. We present robust methods for the covalent conjugation, purification, and characterization of proteins with tetra-sulfonated heptamethine indocyanines, including mass spectroscopic site mapping of highly substituted molecules. One contrast agent, NIR fluorescent human serum albumin (HSA800), emerged as the molecule with the best overall performance with respect to entry to lymphatics, flow to the SLN, retention in the SLN, fluorescence yield and reproducibility. This preclinical study, performed on large animals approaching the size of humans, should serve as a foundation for future clinical studies.
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92
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Milstein AB, Webb KJ, Bouman CA. Estimation of kinetic model parameters in fluorescence optical diffusion tomography. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2005; 22:1357-68. [PMID: 16053157 DOI: 10.1364/josaa.22.001357] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We present a technique for reconstructing the spatially dependent dynamics of a fluorescent contrast agent in turbid media. The dynamic behavior is described by linear and nonlinear parameters of a compartmental model or some other model with a deterministic functional form. The method extends our previous work in fluorescence optical diffusion tomography by parametrically reconstructing the time-dependent fluorescent yield. The reconstruction uses a Bayesian framework and parametric iterative coordinate descent optimization, which is closely related to Gauss-Seidel methods. We demonstrate the method with a simulation study.
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Affiliation(s)
- Adam B Milstein
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907-2035, USA
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93
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Abstract
Various stem cells hold promise for the treatment of human cardiovascular disease. Regardless of stem cell origin, future clinical trials will require that the location and number of such cells be tracked in vivo, over long periods of time. The problem of tracking small numbers of cells in the body is a difficult one, and an optimal solution does not yet exist. We review the many contrast agents and detectors that have been proposed for stem cell tracking during clinical trials, define the characteristics of an ideal imaging technology, and suggest future directions for research.
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Affiliation(s)
- John V Frangioni
- Division of Hematology/Oncology, Department of Radiology, and Molecular Imaging Center, Beth Israel Deaconess Medical Center, 330 Brookline Ave, SL-B05, Boston, Mass 02215, USA.
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94
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Perlitz C, Licha K, Scholle FD, Ebert B, Bahner M, Hauff P, Moesta KT, Schirner M. Comparison of Two Tricarbocyanine-Based Dyes for Fluorescence Optical Imaging. J Fluoresc 2005; 15:443-54. [PMID: 15986163 DOI: 10.1007/s10895-005-2636-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 12/22/2004] [Indexed: 11/29/2022]
Abstract
Optical technologies are evolving in many biomedical areas including the biomedical imaging disciplines. Regarding the absorption properties of physiological molecules in living tissue, the optical window ranging from 700 to 900 nm allows to use fluorescent dyes for novel diagnostic solutions. Here we investigate the potential of two different carbocyanine-based dyes fluorescent in the near infrared as contrast agents for in vivo imaging of subcutaneously grown tumours in laboratory animals. The primary aim was to modify the physicochemical properties of the previously synthesized dye SIDAG to investigate the effect on the in vivo imaging properties.
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Affiliation(s)
- Christin Perlitz
- Optical Imaging and New Modalities Research, Research Laboratories, Schering AG, Müllerstrasse, 13342 Berlin, Germany.
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95
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Swartling J, Svensson J, Bengtsson D, Terike K, Andersson-Engels S. Fluorescence spectra provide information on the depth of fluorescent lesions in tissue. APPLIED OPTICS 2005; 44:1934-41. [PMID: 15813529 DOI: 10.1364/ao.44.001934] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The fluorescence spectrum measured from a fluorophore in tissue is affected by the absorption and scattering properties of the tissue, as well as by the measurement geometry. We analyze this effect with Monte Carlo simulations and by measurements on phantoms. The spectral changes can be used to estimate the depth of a fluorescent lesion embedded in the tissue by measurement of the fluorescence signal in different wavelength bands. By taking the ratio between the signals at two wavelengths, we show that it is possible to determine the depth of the lesion. Simulations were performed and validated by measurements on a phantom in the wavelength range 815-930 nm. The depth of a fluorescing layer could be determined with 0.6-mm accuracy down to at least a depth of 10 mm. Monte Carlo simulations were also performed for different tissue types of various composition. The results indicate that depth estimation of a lesion should be possible with 2-3-mm accuracy, with no assumptions made about the optical properties, for a wide range of tissues.
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Affiliation(s)
- Johannes Swartling
- Department of Physics, Lund Institute of Technology, P.O. Box 118, SE-22100 Lund, Sweden.
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96
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Saxena V, Sadoqi M, Shao J. Enhanced photo-stability, thermal-stability and aqueous-stability of indocyanine green in polymeric nanoparticulate systems. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2005; 74:29-38. [PMID: 15043844 DOI: 10.1016/j.jphotobiol.2004.01.002] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2003] [Revised: 01/02/2004] [Accepted: 01/04/2004] [Indexed: 11/17/2022]
Abstract
Photo-degradation, thermal-degradation and aqueous-instability of indocyanine green (ICG) limits its application as a fluorescence contrast agent for imaging purposes. Thus, the objective of this study is to develop polymeric nanoparticles entrapping ICG and to establish its effectiveness in providing photo-stability, thermal stability and aqueous stability to ICG. Nanoparticles entrapping ICG were engineered, characterized and the degradation kinetics of ICG in the nanoparticles was investigated in aqueous media. The entrapment of ICG in the nanoparticles causes a shift in its wavelength of peak fluorescence and a decrease in its peak fluorescence intensity. The degradation of ICG in aqueous nanoparticle suspension followed first-order kinetics for the time period studied. ICG entrapment in the nanoparticles enhanced aqueous-stability of ICG (half-life, t(1/2) was 72.2+/-6.1 h for ICG in the nanoparticles as compared to 16.8+/-1.5 h for free ICG solution), photo-stability of ICG (t(1/2) was 73.7+/-7.5 h for ICG in the nanoparticles as compared to 14.4+/-2.4 h for free ICG solution when exposed to room light from two 32 W normal fluorescent tubes) and thermal-stability of ICG (t(1/2) of ICG at 42 degrees C was 62.4+/-1.7 h for ICG in the nanoparticles as compared to 10.1+/-0.6 h for free ICG solution).
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Affiliation(s)
- Vishal Saxena
- Department of Pharmacy and Administrative Sciences, College of Pharmacy and Allied Health Professions, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
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97
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Heine HL, Leong HS, Rossi FMV, McManus BM, Podor TJ. Strategies of Conditional Gene Expression in Myocardium. MOLECULAR CARDIOLOGY 2005; 112:109-54. [PMID: 16010014 DOI: 10.1007/978-1-59259-879-3_8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The use of specialized reporter genes to monitor real-time, tissue-specific transgene expression in animal models offers an opportunity to circumvent current limitations associated with the establishment of transgenic mouse models. The Cre-loxP and the tetracycline (Tet)-inducible systems are useful methods of conditional gene expression that allow spatial (cell-type-specific) and temporal (inducer-dependent) control. Most often, the alpha-myosin heavy chain (alpha-MHC) promoter is used in these inducible systems to restrict expression of reporter genes and transgenes to the myocardium. An overview of each inducible system is described, along with suggested reporter genes for real-time, noninvasive imaging in the myocardium. Effective gene delivery of the inducible gene expression system is carried out by lentiviral vectors, which offer high transduction efficiency, long-term transgene expression, and low immunogenicity. This chapter outlines the packaging of myocardium-specific inducible expression systems into lentiviral vectors, in which a transgene and a reporter gene are transduced into cardiomyocytes. In doing so, transgene and reporter expression can be monitored/tracked with bioluminescence imaging (BLI) and positron emission tomography (PET).
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Affiliation(s)
- Heather L Heine
- The James Hogg iCAPTURE Center for Cardiovascular and Pulmonary Research/MRL, University of British Columbia, St. Paul's Hospital, Vancouver, Canada
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98
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Abstract
Accurate and rapid detection of tumors is of great importance for interrogating the molecular basis of cancer pathogenesis, preventing the onset of complications, and implementing a tailored therapeutic regimen. In this era of molecular medicine, molecular probes that respond to, or target molecular processes are indispensable. Although numerous imaging modalities have been developed for visualizing pathologic conditions, the high sensitivity and relatively innocuous low energy radiation of optical imaging method makes it attractive for molecular imaging. While many human diseases have been studied successfully by using intrinsic optical properties of normal and pathologic tissues, molecular imaging of the expression of aberrant genes, proteins, and other pathophysiologic processes would be enhanced by the use of highly specific exogenous molecular beacons. This review focuses on the development of receptor-specific molecular probes for optical imaging of tumors. Particularly, bioconjugates of probes that absorb and fluoresce in the near infrared wavelengths between 750 and 900 nm will be reviewed.
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Affiliation(s)
- Samuel Achilefu
- Department of Radiology, Washington University School of Medicine, 4525 Scot Avenue, St. Louis, MO 63110, USA.
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99
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Gandjbakhche AH, Chernomordik V, Hattery D, Hassan M, Gannot I. Tissue characterization by quantitative optical imaging methods. Technol Cancer Res Treat 2004; 2:537-51. [PMID: 14640765 DOI: 10.1177/153303460300200606] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Optical methods have a long history in the field of medical diagnosis. The biomolecular specificity possible with optical methods has been particularly valuable in microscopy and histopathology while in vivo imaging of deep structures has traditionally been the domain of X-ray and MRI. The use of optical methods in deep tissue has been limited by multiple-scattering which blurs or distorts the optical signal. New stochastic methods which account for multiple scattering have been developed that are extending the usefulness of optical methods deep into tissue. In optical mammography, photons may travel through 10 cm of tissue before arriving at the detector. We have developed a method for quantifying parameters of anomalous sites in breast tissue that may be used for functional characterization of tumors. In other work presented here, we are developing fluorescence based methods to detect and monitor tumor status. The immune response to a tumor is a target for fluorescently labeled specific antibodies. We have developed a method to localize the tumor site using CW fluorescence. Additionally, we have developed a method which uses time-resolved data and capitalizes on probe lifetime sensitivity to metabolic parameters such as pH and temperature to obtain functional information from the tumor site.
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Affiliation(s)
- Amir H Gandjbakhche
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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100
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Milstein AB, Stott JJ, Oh S, Boas DA, Millane RP, Bouman CA, Webb KJ. Fluorescence optical diffusion tomography using multiple-frequency data. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2004; 21:1035-49. [PMID: 15191186 DOI: 10.1364/josaa.21.001035] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A method is presented for fluorescence optical diffusion tomography in turbid media using multiple-frequency data. The method uses a frequency-domain diffusion equation model to reconstruct the fluorescent yield and lifetime by means of a Bayesian framework and an efficient, nonlinear optimizer. The method is demonstrated by using simulations and laboratory experiments to show that reconstruction quality can be improved in certain problems through the use of more than one frequency. A broadly applicable mutual information performance metric is also presented and used to investigate the advantages of using multiple modulation frequencies compared with using only one.
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Affiliation(s)
- Adam B Milstein
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907-2035, USA
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