Browsing by Author "Bouchard, Richard R."

Now showing 1 - 6 of 6
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    Clinically translatable quantitative molecular photoacoustic imaging with liposome-encapsulated ICG J-aggregates
    (Springer Nature, 2021) Wood, Cayla A.; Han, Sangheon; Kim, Chang Soo; Wen, Yunfei; Sampaio, Diego R. T.; Harris, Justin T.; Homan, Kimberly A.; Swain, Jody L.; Emelianov, Stanislav Y.; Sood, Anil K.; Cook, Jason R.; Sokolov, Konstantin V.; Bouchard, Richard R.
    Photoacoustic (PA) imaging is a functional and molecular imaging technique capable of high sensitivity and spatiotemporal resolution at depth. Widespread use of PA imaging, however, is limited by currently available contrast agents, which either lack PA-signal-generation ability for deep imaging or their absorbance spectra overlap with hemoglobin, reducing sensitivity. Here we report on a PA contrast agent based on targeted liposomes loaded with J-aggregated indocyanine green (ICG) dye (i.e., PAtrace) that we synthesized, bioconjugated, and characterized to addresses these limitations. We then validated PAtrace in phantom, in vitro, and in vivo PA imaging environments for both spectral unmixing accuracy and targeting efficacy in a folate receptor alpha-positive ovarian cancer model. These study results show that PAtrace concurrently provides significantly improved contrast-agent quantification/sensitivity and SO2 estimation accuracy compared to monomeric ICG. PAtrace’s performance attributes and composition of FDA-approved components make it a promising agent for future clinical molecular PA imaging.
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    Computational modeling and minimization of unintended neuronal excitation in a LIFU stimulation
    (Springer Nature, 2023) Fan, Boqiang; Goodman, Wayne; Cho, Raymond Y.; Sheth, Sameer A.; Bouchard, Richard R.; Aazhang, Behnaam
    The neuromodulation effect of low-intensity focused ultrasound (LIFU) is highly target-specific. Unintended off-target neuronal excitation can be elicited when the beam focusing accuracy and resolution are limited, whereas the resulted side effect has not been evaluated quantitatively. There is also a lack of methods addressing the minimization of such side effects. Therefore, this work introduces a computational model of unintended neuronal excitation during LIFU neuromodulation, which evaluates the off-target activation area (OTAA) by integrating an ultrasound field model with the neuronal spiking model. In addition, a phased array beam focusing scheme called constrained optimal resolution beamforming (CORB) is proposed to minimize the off-target neuronal excitation area while ensuring effective stimulation in the target brain region. A lower bound of the OTAA is analytically approximated in a simplified homogeneous medium, which could guide the selection of transducer parameters such as aperture size and operating frequency. Simulations in a human head model using three transducer setups show that CORB markedly reduces the OTAA compared with two benchmark beam focusing methods. The high neuromodulation resolution demonstrates the capability of LIFU to effectively limit the side effects during neuromodulation, allowing future clinical applications such as treatment of neuropsychiatric disorders.
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    Fluorinated Graphene Oxide: a New Multimodal Material for Biological Applications
    (Wiley, 2013) Romero-Aburto, Rebeca; Narayanan, Tharangattu N.; Nagaoka, Yutaka; Hasumura, Takashi; Mitcham, Trevor M.; Fukuda, Takahiro; Cox, Paris J.; Bouchard, Richard R.; Maekawa, Toru; Kumar, Sakthi; Torti, Suzy V.; Mani, Sendurai A.; Ajayan, Pulickel M.
    Fluorinated graphene oxide (FGO) is reported for the first time as a magnetically responsive drug carrier that can serve as a MRI and photoacoustic contrast agent, under pre-clinical settings, as well as a photothermal therapy Its hydrophilic nature facilitates biocompatibility. FGO as a broad wavelength absorber, with high charge transfer and strong nonlinear scattering is optimal for NIR laser-induced hyperthermia.
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    Multi-stimuli responsive Cu2S nanocrystals as trimodal imaging and synergistic chemo-photothermal therapy agents
    (Royal Society of Chemistry, 2015) Poulose, Aby Cheruvathoor; Veeranarayanan, Srivani; Mohamed, M. Sheikh; Nagaoka, Yutaka; Aburto, Rebeca Romero; Mitcham, Trevor; Ajayan, Pulickel M.; Bouchard, Richard R.; Sakamoto, Yasushi; Yoshida, Yasuhiko; Maekawa, Toru; Kumar, D. Sakthi
    A size and shape tuned, multifunctional metal chalcogenide, Cu2S-based nanotheranostic agent is developed for trimodal imaging and multimodal therapeutics against brain cancer cells. This theranostic agent was highly efficient in optical, photoacoustic and X-ray contrast imaging systems. The folate targeted NIR-responsive photothermal ablation in synergism with the chemotherapeutic action of doxorubicin proved to be a rapid precision guided cancer-killing module. The multi-stimuli, i.e., pH-, thermo- and photo-responsive drug release behavior of the nanoconjugates opens up a wider corridor for on-demand triggered drug administration. The simple synthesis protocol, combined with the multitudes of interesting features packed into a single nanoformulation, clearly demonstrates the competing role of this Cu2S nanosystem in future cancer treatment strategies.
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    Multifunctional Cu2−xTe Nanocubes Mediated Combination Therapy for Multi-Drug Resistant MDA MB 453
    (Springer Nature, 2016) Poulose, Aby Cheruvathoor; Veeranarayanan, Srivani; Mohamed, M. Sheikh; Aburto, Rebeca Romero; Mitcham, Trevor; Bouchard, Richard R.; Ajayan, Pulickel M.; Sakamoto, Yasushi; Maekawa, Toru; Kumar, D. Sakthi
    Hypermethylated cancer populations are hard to treat due to their enhanced chemo-resistance, characterized by aberrant methylated DNA subunits. Herein, we report on invoking response from such a cancer lineage to chemotherapy utilizing multifunctional copper telluride (Cu2−XTe) nanocubes (NCs) as photothermal and photodynamic agents, leading to significant anticancer activity. The NCs additionally possessed photoacoustic and X-ray contrast imaging abilities that could serve in image-guided therapeutic studies.
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    Projection-based stereolithography for direct 3D printing of heterogeneous ultrasound phantoms
    (Public Library of Science, 2021) Paulsen, Samantha J.; Mitcham, Trevor M.; Pan, Charlene S.; Long, James; Grigoryan, Bagrat; Sazer, Daniel W.; Harlan, Collin J.; Janson, Kevin D.; Pagel, Mark D.; Miller, Jordan S.; Bouchard, Richard R.
    Modern ultrasound (US) imaging is increasing its clinical impact, particularly with the introduction of US-based quantitative imaging biomarkers. Continued development and validation of such novel imaging approaches requires imaging phantoms that recapitulate the underlying anatomy and pathology of interest. However, current US phantom designs are generally too simplistic to emulate the structure and variability of the human body. Therefore, there is a need to create a platform that is capable of generating well-characterized phantoms that can mimic the basic anatomical, functional, and mechanical properties of native tissues and pathologies. Using a 3D-printing technique based on stereolithography, we fabricated US phantoms using soft materials in a single fabrication session, without the need for material casting or back-filling. With this technique, we induced variable levels of stable US backscatter in our printed materials in anatomically relevant 3D patterns. Additionally, we controlled phantom stiffness from 7 to >120 kPa at the voxel level to generate isotropic and anisotropic phantoms for elasticity imaging. Lastly, we demonstrated the fabrication of channels with diameters as small as 60 micrometers and with complex geometry (e.g., tortuosity) capable of supporting blood-mimicking fluid flow. Collectively, these results show that projection-based stereolithography allows for customizable fabrication of complex US phantoms.