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https://www.readbyqxmd.com/read/28106206/moo3-x-quantum-dots-for-photoacoustic-imaging-guided-photothermal-photodynamic-cancer-treatment
#1
Dandan Ding, Wei Guo, Chongshen Guo, Jianzhe Sun, Nannan Zheng, Fei Wang, Mei Yan, Shaoqin Liu
A theranostic system of image-guided phototherapy is considered as a potential technique for cancer treatment because of the ability to integrate diagnostics and therapies together, thus enhancing accuracy and visualization during the treatment. In this work, we realized photoacoustic (PA) imaging-guided photothermal (PT)/photodynamic (PD) combined cancer treatment just via a single material, MoO3-x quantum dots (QDs). Due to their strong NIR harvesting ability, MoO3-x QDs can convert incident light into hyperthermia and sensitize the formation of singlet oxygen synchronously as evidenced by in vitro assay, hence, they can behave as both PT and PD agents effectively and act as a "dual-punch" to cancer cells...
January 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28101405/deep-tissue-photoacoustic-computed-tomography-with-a-fast-and-compact-laser-system
#2
Depeng Wang, Yuehang Wang, Weiran Wang, Dandan Luo, Upendra Chitgupi, Jumin Geng, Yang Zhou, Lidai Wang, Jonathan F Lovell, Jun Xia
Photoacoustic computed tomography (PACT) holds great promise for biomedical imaging, but wide-spread implementation is impeded by the bulkiness of flash-lamp-pumped laser systems, which typically weigh between 50 - 200 kg, require continuous water cooling, and operate at a low repetition rate. Here, we demonstrate that compact lasers based on emerging diode technologies are well-suited for preclinical and clinical PACT. The diode-pumped laser used in this study had a miniature footprint (13 × 14 × 7 cm(3)), weighed only 1...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28101402/identification-and-removal-of-laser-induced-noise-in-photoacoustic-imaging-using-singular-value-decomposition
#3
Emma R Hill, Wenfeng Xia, Matthew J Clarkson, Adrien E Desjardins
Singular value decomposition (SVD) was used to identify and remove laser-induced noise in photoacoustic images acquired with a clinical ultrasound scanner. This noise, which was prominent in the radiofrequency data acquired in parallel from multiple transducer elements, was induced by the excitation light source. It was modelled by truncating the SVD matrices so that only the first few largest singular value components were retained, and subtracted prior to image reconstruction. The dependency of the signal amplitude and the number of the largest singular value components used for noise modeling was investigated for different photoacoustic source geometries...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28098201/fiber-laser-based-ultrasound-sensor-for-photoacoustic-imaging
#4
Yizhi Liang, Long Jin, Lidai Wang, Xue Bai, Linghao Cheng, Bai-Ou Guan
Photoacoustic imaging, especially for intravascular and endoscopic applications, requires ultrasound probes with miniature size and high sensitivity. In this paper, we present a new photoacoustic sensor based on a small-sized fiber laser. Incident ultrasound waves exert pressures on the optical fiber laser and induce harmonic vibrations of the fiber, which is detected by the frequency shift of the beating signal between the two orthogonal polarization modes in the fiber laser. This ultrasound sensor presents a noise-equivalent pressure of 40 Pa over a 50-MHz bandwidth...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28092507/real-time-intravascular-ultrasound-and-photoacoustic-imaging
#5
Donald VanderLaan, Andrei B Karpiouk, Doug Yeager, Stanislav Emelianov
Combined intravascular ultrasound and intravascular photoacoustic (IVUS/IVPA) imaging is an emerging hybrid modality being explored as a means of improving the characterization of atherosclerotic plaque anatomical and compositional features. While initial demonstrations of the technique have been encouraging, they have been limited by catheter rotation and data acquisition, displaying, and processing rates on the order of several seconds per frame as well as the use of off-line image processing. Herein, we present a complete IVUS/IVPA imaging system and method capable of real-time IVUS/IVPA imaging, with online data acquisition, image processing, and display of both IVUS and IVPA images...
January 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28091571/photoacoustic-pump-probe-tomography-of-fluorophores-in-vivo-using-interleaved-image-acquisition-for-motion-suppression
#6
Julia Märk, Asja Wagener, Edward Zhang, Jan Laufer
In fluorophores, the excited state lifetime can be modulated using pump-probe excitation. By generating photoacoustic (PA) signals using simultaneous and time-delayed pump and probe excitation pulses at fluences below the maximum permissible exposure, a modulation of the signal amplitude is observed in fluorophores but not in endogenous chromophores. This provides a highly specific contrast mechanism that can be used to recover the location of the fluorophore using difference imaging. The practical challenges in applying this method to in vivo PA tomography include the typically low concentrations of fluorescent contrast agents, and tissue motion...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28088080/a-computer-based-simulator-for-intravascular-photoacoustic-images
#7
Sun Zheng, Yuan Yuan, Han Duoduo
Intravascular photoacoustic (IVPA) is a newly developed catheter-based imaging technique for the diagnosis of arterial atherosclerosis. A framework of simulating IVPA transversal images from a cross-sectional vessel model with given optical and acoustic parameters was presented. The light illumination and transportation in multi-layered wall and atherosclerotic plaque tissues were modeled through Monte Carlo (MC) simulation. The generation and transmission of photoacoustic (PA) waves in the acoustically homogeneous medium were modeled through the PA wave equation, which is solved explicitly with a finite difference time domain (FDTD) algorithm in polar coordinates...
January 6, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28081216/real-time-monitoring-of-placental-oxygenation-during-maternal-hypoxia-and-hyperoxygenation-using-photoacoustic-imaging
#8
Chloé J Arthuis, Anthony Novell, Florian Raes, Jean-Michel Escoffre, Stéphanie Lerondel, Alain Le Pape, Ayache Bouakaz, Franck Perrotin
PURPOSE: This preclinical study aimed to evaluate placental oxygenation in pregnant rats by real-time photoacoustic (PA) imaging on different days of gestation and to specify variations in placental oxygen saturation under conditions of maternal hypoxia and hyperoxygenation. MATERIAL AND METHODS: Placentas of fifteen Sprague-Dawley rats were examined on days 14, 17, and 20 of pregnancy with a PA imaging system coupled to high-resolution ultrasound imaging. Pregnant rats were successively exposed to hyperoxygenated and hypoxic conditions by changing the oxygen concentration in inhaled gas...
2017: PloS One
https://www.readbyqxmd.com/read/28081069/photoacoustic-imaging-of-sub-diffraction-objects-with-spectral-contrast
#9
Sophinese Iskander-Rizk, Pieter Kruizinga, Geert Springeling, Hendrik J Vos, Antonius F W van der Steen, Gijs van Soest
Photoacoustic imaging couples the chemical specificity of optical absorption with the viewing depth of ultrasound. Systems based on linear array transducers have the versatility to be applied in various (pre-) clinical scenarios but face a trade-off between viewing depth and image resolution depending on transducer frequency and aperture. We propose here a method to disentangle, with precision, small, closely spaced targets with optical spectral contrast, without impairing the imaging depth. Photoacoustic data sets were recorded at two different optical wavelengths...
January 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28076457/removal-of-calcium-hydroxide-from-weine-type-ii-systems-using-photon-induced-photoacoustic-streaming-passive-ultrasonic-and-needle-irrigation-a-microcomputed-tomography-study
#10
Adam Lloyd, Geraldine Navarrete, Melissa Andreia Marchesan, David Clement
Objective: This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars. Material and Methods: Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/...
November 2016: Journal of Applied Oral Science: Revista FOB
https://www.readbyqxmd.com/read/28072536/role-of-ionic-strength-and-ph-in-modulating-thermodynamic-profiles-associated-with-co-escape-from-rice-nonsymbiotic-hemoglobin-1
#11
David Butcher, Sophie Bernad, Valerie Derrien, Pierre Sebban, Jaroslava Miksovska
Type 1 nonsymbiotic hemoglobins are found in a wide variety of land plants and exhibit very high affinities for exogenous gaseous ligands. These proteins are presumed to have a role in protecting plant cells from oxidative stress under etiolated/hypoxic conditions through NO dioxygenase activity. In this study we have employed photoacoustic calorimetry, time-resolved absorption spectroscopy, and classical molecular dynamics simulations in order to elucidate thermodynamics, kinetics, and ligand migration pathways upon CO photodissociation from WT and a H73L mutant of type 1 nonsymbiotic hemoglobin from Oryza sativa (rice)...
January 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28067380/a-single-light-triggered-and-dual-imaging-guided-multifunctional-platform-for-combined-photothermal-and-photodynamic-therapy-based-on-td-controlled-and-icg-loaded-cus-msio2
#12
Qing You, Qi Sun, Jinping Wang, Xiaoxiao Tan, Xiaojuan Pang, Li Liu, Meng Yu, Fengping Tan, Nan Li
Near-infrared (NIR)-responsive drug delivery systems have received enormous attention because of their good biocompatibility and high biological penetration. In this work, we report a novel 1-tetradecanol (TD)-controlled and indocyanine green (ICG)-loaded CuS@mSiO2 phototherapy nanoplatform (CuS@mSiO2-TD/ICG). The CuS@mSiO2 nanoparticles prepared by a facile one-pot approach can serve as drug-delivery vehicles to transport the NIR absorbing phototherapeutic agent (ICG) within the mesoporous cavities. Meanwhile a phase-change molecule (PCM), TD, is introduced as a thermosensitive gatekeeper to avoid the premature release of loaded ICG...
January 9, 2017: Nanoscale
https://www.readbyqxmd.com/read/28066027/light-source-effects-on-aerosol-photoacoustic-spectroscopy-measurements
#13
James G Radney, Christopher D Zangmeister
Photoacoustic spectroscopy measurements of flame-generated soot aerosol coated with small amounts of water yielded absorption enhancements that were dependent on the laser used: quasi-continuous wave (Q-CW, ≈ 650 ps pulse duration and 78 MHz repetition rate) versus continuous wave (CW). Water coating thickness was controlled by exposing the aerosol to a set relative humidity (RH). At ≈ 85 % RH, the mass of the soot particles increased by an amount comparable to a monolayer of water being deposited and enhanced the measured absorption by 36 % and 15 % for the Q-CW and CW lasers, respectively...
January 2017: Journal of Quantitative Spectroscopy & Radiative Transfer
https://www.readbyqxmd.com/read/28064138/ultrasensitive-photoacoustic-sensor-based-on-quantum-cascade-laser-spectroscopy
#14
Deepak Kumar, Surya Gautam, Subodh Kumar, Saurabh Gupta, Hari B Srivastava, Surya N Thakur, Ramesh C Sharma
The paper focuses on development of ultra-sonic detection system based on laser photoacoustic spectroscopic technique and processing of signal for detection of very low quantity chemicals, explosive materials, and mixtures of these hazardous molecules. The detection system has been developed for the first time with specially designed one side open photo-acoustic cell having high quality factor. Explosive and Hazardous materials like RDX, DNT, PETN, Gun Powder, TATP (Tri acetone tri-peroxide) and their simulants like Acetone were detected in 7 to 9μm wavelength band...
November 23, 2016: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28060458/til4-coordinated-black-phosphorus-quantum-dots-as-an-efficient-contrast-agent-for-in-vivo-photoacoustic-imaging-of-cancer
#15
Zhengbo Sun, Yuetao Zhao, Zhibin Li, Haodong Cui, Yayan Zhou, Weihao Li, Wei Tao, Han Zhang, Huaiyu Wang, Paul K Chu, Xue-Feng Yu
Black phosphorus quantum dots coordinated with a sulfonic ester of the titanium ligand are prepared and exhibit enhanced stability. In vitro and in vivo photoacoustic imaging applications demonstrate that the quantum dots can efficiently accumulate inside the tumor producing tumor profiles with high spatial resolution, demonstrating their potential as an efficient agent for photoacoustic imaging.
January 6, 2017: Small
https://www.readbyqxmd.com/read/28059418/highly-versatile-spion-encapsulated-plga-nanoparticles-as-photothermal-ablators-of-cancer-cells-and-as-multimodal-imaging-agents
#16
Balasubramanian Sivakumar, Ravindran Girija Aswathy, Rebeca Romero-Aburto, Trevor Mitcham, Keith A Mitchel, Yutaka Nagaoka, Richard R Bouchard, Pulickel M Ajayan, Toru Maekawa, Dasappan Nair Sakthikumar
We have designed versatile polymeric nanoparticles with cancer cell specific targeting capabilities via aptamer conjugation after the successful encapsulation of curcumin and superparamagnetic iron oxide nanoparticles (SPIONs) inside a PLGA nanocapsule. These targeted nanocomposites were selectively taken up by tumor cells, under in vitro conditions, demonstrating the effectiveness of the aptamer targeting mechanism. Moreover, the nanocomposite potentially functioned as efficient multiprobes for optical, magnetic resonance imaging (MRI) and photoacoustic imaging contrast agents in the field of cancer diagnostics...
January 6, 2017: Biomaterials Science
https://www.readbyqxmd.com/read/28059409/in-vivo-photoacoustic-tumor-tomography-using-a-quinoline-annulated-porphyrin-as-nir-molecular-contrast-agent
#17
Michael Luciano, Mohsen Erfanzadeh, Feifei Zhou, Hua Zhu, Tobias Bornhütter, Beate Röder, Quing Zhu, Christian Brückner
The synthesis and photophysical properties of a tetra-PEG-modified and freely water-soluble quinoline-annulated porphyrin are described. We previously demonstrated the ability of quinoline-annulated porphyrins to act as an in vitro NIR photoacoustic imaging (PAI) contrast agent. The solubility of the quinoline-annulated porphyrin derivative in serum now allowed the assessment of the efficacy of the PEGylated derivative as an in vivo NIR contrast agent for the PAI of an implanted tumor in a mouse model. A multi-fold contrast enhancement when compared to the benchmark dye ICG could be shown, a finding that could be traced to its photophysical properties (short triplet lifetimes, low fluorescence and singlet oxygen sensitization quantum yields)...
January 6, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28058834/ph-dependent-transmembrane-activity-of-peptide-functionalized-gold-nanostars-for-computed-tomography-photoacoustic-imaging-and-photothermal-therapy
#18
Ying Tian, Yunlei Zhang, Zhaogang Teng, Wei Tian, Song Luo, Xiang Kong, Xiaodan Su, Yuxia Tang, Shouju Wang, Guangming Lu
Progress in multifunctional nanomaterials for tumor therapy mostly depends on the development of tumor-targeting delivery strategies. One approach is to explore a pH-responsive strategy to target the slightly acidic solid tumor microenvironment. A novel class of pH (low) insertion peptides (pHLIPs) with pH-dependent transmembrane activity can fold and rapidly insert into the lipid bilayer of tumor cells triggered by acidity, facilitating the cellular internalization of nanomaterials synchronously. Here, we innovatively decorated gold nanostars (GNSs) with pHLIPs (GNS-pHLIP) to improve their targeting ability and photothermal therapeutic (PTT) efficiency...
January 6, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28053532/biomedical-photoacoustics-fundamentals-instrumentation-and-perspectives-on-nanomedicine
#19
Chunpeng Zou, Beibei Wu, Yanyan Dong, Zhangwei Song, Yaping Zhao, Xianwei Ni, Yan Yang, Zhe Liu
Photoacoustic imaging (PAI) is an integrated biomedical imaging modality which combines the advantages of acoustic deep penetration and optical high sensitivity. It can provide functional and structural images with satisfactory resolution and contrast which could provide abundant pathological information for disease-oriented diagnosis. Therefore, it has found vast applications so far and become a powerful tool of precision nanomedicine. However, the investigation of PAI-based imaging nanomaterials is still in its infancy...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28049896/development-of-molecular-probes-based-on-iron-oxide-nanoparticles-for-in-vivo-magnetic-resonance-photoacoustic-dual-imaging-of-target-molecules-in-tumors
#20
Kohei Sano
 Molecular imaging probes that enable seamless diagnoses of tumors in the preoperative and intraoperative stages could lead to surgical resection of tumors based on highly accurate diagnoses. Because iron oxide nanoparticles (IONPs) have high proton relaxivity and high molar extinction coefficients suitable for magnetic resonance imaging (MRI) and photoacoustic imaging, respectively, we planned to develop molecular imaging probes applicable to the pre- (MRI) and intraoperative (photoacoustic imaging) stages...
2017: Yakugaku Zasshi: Journal of the Pharmaceutical Society of Japan
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