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oe1(光电查) - 科学论文

128 条数据
?? 中文(中国)
  • In Vivo Tumor Photoacoustic Imaging and Photothermal Therapy Based on Supra-(Carbon Nanodots)

    摘要: Carbon nanodots (CNDs) with high photothermal conversion efficiency are considered as emerging nanomaterials for advanced biomedical applications attributing to their high biocompatibility, low-cost, and unique photophysical properties. In previous work, supra-CNDs are synthesized exhibiting high absorption in the near-infrared (NIR) region and good NIR photothermal conversion performance. In this work, supra-CNDs are explored as a photothermal agent for photothermal therapy (PTT) and a contrast agent for photoacoustic (PA) imaging, respectively. As a result, in vivo tumor PTT is realized under 655 nm laser irradiation via intratumor injecting supra-CNDs. In vivo PA imaging reveals that supra-CNDs can accumulate in the tumor tissue via the blood circulation after intravenous injection. Moreover, in vivo PTT is conducted after intravenous injection and subsequent tumor accumulation of supra-CNDs, and the lives of mice are prolonged due to the tumor growth inhibition after PTT. These attractive properties indicate that the supra-CNDs can be used as biomedical agents for PA imaging and tumor therapy.

    关键词: photoacoustic imaging,supracarbon nanodots,photothermal therapy

    更新于2025-09-10 09:29:36

  • Pivotal techniques evaluation in QEPAS system for engineering applications

    摘要: Efforts were made in this study to evaluate a series of pivotal techniques in standard quartz tuning fork (QTF) based quartz enhanced photoacoustic spectroscopy (QEPAS) systems for engineering applications. In current QEPAS systems, a scanning ramp combined with high frequency sinusoidal signal is used to drive the light source for photoacoustic excitation, the scanning cycle was optimized for the first time in experiments guaranteeing that photoacoustic energy accumulation finished to achieve the largest photoacoustic signal, and the optimum modulation index was verified by experiments to be ~5 instead of the simulated result 2.2. As an important step for engineering applications, a long-term (~8 months) experiment was also carried out to evaluate the stability of QTF’s property. In addition, several photoacoustic spectrophone configurations were compared in the optimum geometry parameters, dual-tubes on beam was verified in experiments to be the most efficient one compared with half on-beam and off-beam structures in standard QTF based systems, which is consist with the summary of published papers.

    关键词: Modulation index,Scanning cycle,Long-term stability,Quartz enhanced photoacoustic spectroscopy,Photoacoustic spectrophone

    更新于2025-09-09 09:28:46

  • Alkaline Phosphatase-Triggered Self-Assembly of Near-Infrared Nanoparticles for Enhanced Photoacoustic Imaging of Tumor

    摘要: Photoacoustic (PA) imaging is advantageous for the diagnosis of superficial cancer with high spatial resolution. However, to the best of our knowledge, using an alkaline phosphatase (ALP)-activatable probe for enhanced PA imaging of tumor has not been reported. In this work, we rationally designed a NIR probe IR775-Phe-Phe-Tyr(H2PO3)-OH (1P) for PA imaging ALP activity in vitro and in tumor. Under the catalysis of ALP, 1P was efficiently converted to IR775-Phe-Phe-Tyr-OH (1) which self-assembled into the nanoparticles 1-NPs. Formation of 1-NPs induced a 6.4-fold enhancement of the 795 nm PA signal of 1P. In vivo tumor PA imaging results indicated that, compared with that in the ALP inhibitor-treated control group, PA contrast in the experimental group enhanced 2.3 folds at 4 h post 1P injection. By replacing the Phe-Phe-Tyr(H2PO3)-OH motif in 1P with other enzyme-cleavable ones, we hope more PA probes could be developed for the precise diagnoses of their corresponding cancers in the near future.

    关键词: photoacoustic imaging,near-infrared nanoparticle,alkaline phosphatase,self-assembly

    更新于2025-09-09 09:28:46

  • A Water-soluble, NIR-absorbing Quaterrylenediimide Chromophore for Photoacoustic Imaging and Efficient Photothermal Cancer Therapy

    摘要: Precision phototheranostics, including photoacoustic imaging and photothermal therapy, requires stable photothermal agents. Developing photothermal agents with high stability and high photothermal conversion efficiency (PTCE) remains a considerable challenge in biomedical applications. Herein, we introduce a new photothermal agent based on water-soluble quaterrylenediimide (QDI) that can self-assemble into nanoparticles (QDI-NPs) in aqueous solution. Incorporation of polyethylene glycol (PEG) into the QDI core significantly enhances both physiological stability and biocompatibility of QDI-NPs. These highly photostable QDI-NPs exhibit exciting advantages including intense absorption in the near-infrared (NIR) and high PTCE of up to 64.7 ± 4%. This is higher than that of many other organic photothermal agents, such as graphene or commercial indocyanine green (ICG). Their small size of approximately 10 nm enables a sustained retention in deep tumor sites and at the same time proper clearance from the body. QDI-NPs allow high-resolution photoacoustic imaging and efficient 808 nm laser-triggered photothermal therapy of cancer in vivo. The current study opens a promising way for precision phototheranostics.

    关键词: quaterrylenediimide,photoacoustic imaging,NIR-absorption,pharmacokinetics,photothermal conversion efficiency

    更新于2025-09-09 09:28:46

  • A Water-soluble, NIR-absorbing Quaterrylenediimide Chromophore for Photoacoustic Imaging and Efficient Photothermal Cancer Therapy

    摘要: Precision phototheranostics, including photoacoustic imaging and photothermal therapy, requires stable photothermal agents. Developing photothermal agents with high stability and high photothermal conversion efficiency (PTCE) remains a considerable challenge in biomedical applications. Herein, we introduce a new photothermal agent based on water-soluble quaterrylenediimide (QDI) that can self-assemble into nanoparticles (QDI-NPs) in aqueous solution. Incorporation of polyethylene glycol (PEG) into the QDI core significantly enhances both physiological stability and biocompatibility of QDI-NPs. These highly photostable QDI-NPs exhibit exciting advantages including intense absorption in the near-infrared (NIR) and high PTCE of up to 64.7 ± 4%. This is higher than that of many other organic photothermal agents, such as graphene or commercial indocyanine green (ICG). Their small size of approximately 10 nm enables a sustained retention in deep tumor sites and at the same time proper clearance from the body. QDI-NPs allow high-resolution photoacoustic imaging and efficient 808 nm laser-triggered photothermal therapy of cancer in vivo. The current study opens a promising way for precision phototheranostics.

    关键词: quaterrylenediimide,photoacoustic imaging,NIR-absorption,pharmacokinetics,photothermal conversion efficiency

    更新于2025-09-09 09:28:46

  • Nanosonosensitizers for Highly Efficient Sonodynamic Cancer Theranostics

    摘要: Background: Multifunctional nanoplatforms with diagnostic-imaging and targeted therapeutic functionality (theranostics) are of great interest in the field of precision nanomedicine. The emerging sonodynamic therapy (SDT) combined with sonosensitizers under the guidance of photoacoustic (PA) imaging is highly expected to accurately eliminate cancer cells/tissue. Methods: Unique core/shell-structured theranostic FA-HMME-MNPs-PLGA nanoparticles (FHMP NPs, FA: folate, HMME: hematoporphyrin monomethyl ether, MNPs: melanin nanoparticles, PLGA: poly (lactic-co-glycolic) acid) were constructed by the integration of MNPs (for PA imaging) in the core and HMME in the shell for enhanced PA imaging-guided SDT, which were further functionalized with a tumor-targeting ligand, FA. The PA imaging-guided SDT was systematically and successfully demonstrated both in vitro and in vivo. The high biosafety of FHMP NPs was also systematically evaluated. Results: The synthesized FHMP NPs with a broad optical absorption not only possess high PA-imaging contrast enhancement capability but also exhibit significant SDT efficiency. Importantly, such a PLGA based nanoplatform improved light stability of HMME, enhancing sonodynamic performance and facilitated delivery of MNPs to the tumor region. Meanwhile, a combined effect between HMME and MNPs was discovered and verified. Furthermore, a sonosensitizer assisted by ultrasound irradiation engenders reactive oxygen species (ROS)-mediated cytotoxicity toward tumor cells/tissue. Both in vitro cell-level and systematic in vivo xenograft evaluations on tumor-bearing mice demonstrated that the selective killing effect of ROS on tumor cells was assisted by FHMP NPs, which played an active role in the suppression of tumor growth with high biosafety. Conclusion: A theranostic nanoplatform was successfully constructed, achieving PA imaging-guided SDT against breast cancer cells/tissue. More importantly, MNPs and HMME in one platform with combined effect for enhancing PA imaging was demonstrated. This unique theranostic nanoplatform with multiple capabilities paves a new way toward personalized medicine by rational utilization.

    关键词: Nanosonosensitizers,Nanomedicine,Sonodynamic therapy,Photoacoustic imaging,HMME,Melanin

    更新于2025-09-09 09:28:46

  • Thermal conductivity of silicon nanomaterials measured using the photoacoustic technique in a piezoelectric configuration

    摘要: In this study, we investigated the thermal transport in porous silicon nanostructures and silicon nanowires fabricated by electrochemical and metal-assisted chemical etching processes, respectively. In particular, the thermal conductivity values for the silicon-based nanomaterials were estimated based on photoacoustic measurements obtained from piezoelectric recordings. The amplitude–frequency and phase–frequency dependencies of the photoacoustic responses of the nanostructured silicon samples were obtained, and simulated successfully with a theoretical model. Correlations were established between the thermal conductivities and etching parameters.

    关键词: Silicon nanomaterial,Piezoelectric recording,Thermal conductivity,Photoacoustic technique

    更新于2025-09-09 09:28:46

  • Comprehensive Characterization of Cerebrovascular Dysfunction in Blast Traumatic Brain Injury Using Photoacoustic Microscopy

    摘要: Blast traumatic brain injury (bTBI) is a leading contributor to combat-related injuries and death. Although substantial emphasis has been placed on blast-induced neuronal and axonal injuries, co-existing dysfunctions in the cerebral vasculature, particularly the microvasculature, remain poorly understood. Here, we studied blast-induced cerebrovascular dysfunctions in a rat model of bTBI (blast overpressure: 187.8±18.3 kPa). Using photoacoustic microscopy, we quantified changes in cerebral hemodynamics and metabolism—including blood perfusion, oxygenation, flow, oxygen extraction fraction, and the metabolic rate of oxygen—4 hours post-injury. Moreover, we assessed the effect of blast exposure on cerebrovascular reactivity to vasodilatory stimulation. With vessel segmentation, we extracted these changes at the single-vessel level, revealing their dependence on vessel type (i.e., artery vs. vein) and diameter. We found that bTBI at this pressure level did not induce pronounced baseline changes in cerebrovascular diameter, blood perfusion, oxygenation, flow, oxygen extraction and metabolism, except for a slight sO2 increase in small veins (<45 μm) and blood flow increase in large veins (≥45 μm). In contrast, this blast exposure almost abolished cerebrovascular reactivity, including arterial dilation, flow upregulation, and venous sO2 increase. This study is the most comprehensive assessment of cerebrovascular structure and physiology in response to blast exposure to date. The observed impairment in cerebrovascular reactivity can potentially cause cognitive decline due to the mismatch between cognitive metabolic demands and vessel’s ability to dynamically respond to meet the demands. Also, the impaired cerebrovascular reactivity can lead to increased vulnerability of the brain to metabolic insults, including hypoxia and ischemia.

    关键词: blast traumatic brain injury,cerebrovascular reactivity,photoacoustic microscopy,oxygen metabolism,hemodynamics

    更新于2025-09-09 09:28:46

  • Passive ultrasound aided acoustic resolution photoacoustic microscopy imaging for layered heterogeneous media

    摘要: Photoacoustic imaging reconstructions usually assume a known speed-of-sound (SOS) distribution; however, in most cases, the SOS distribution is not revealed and is dif?cult to estimate from photoacoustic signals. In this paper, we propose passive ultrasound aided acoustic resolution photoacoustic microscopy which simultaneously reconstructs SOS distributions and photoacoustic images for layered heterogeneous media. The passive ultrasound is a kind of laser-induced acoustic wave generated by a transducer absorbing the backscattered light. It can be used to measure the layer thicknesses due to its sensitivity to structural information and broad bandwidth and further determine the SOS distributions. After estimating the SOS distributions, a phase shift plus interpo- lation is employed to reconstruct the photoacoustic image for heterogeneous media. Without intro- ducing additional hardware, this method can be conveniently incorporated into a conventional photoacoustic imaging system. A curved shell immersed in water is adopted as a layered heteroge- neous phantom, and the proposed method reconstructs the targets (carbon rods) under this shell. Under the test of a 5 MHz focused transducer (NA 0.25), the maximum reconstruction deviation of 1.2 mm carbon rods is only 0.15 mm.

    关键词: passive ultrasound,speed-of-sound distribution,acoustic resolution photoacoustic microscopy,layered heterogeneous media,photoacoustic imaging

    更新于2025-09-04 15:30:14

  • [IEEE 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Singapore, Singapore (2018.4.22-2018.4.26)] 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - From Nanostructured Piezoelectric Materials to Broadband Transducers for High Resolution Ultrasonic Imaging

    摘要: One-dimensional (1D) piezoelectric nanotubes have been fabricated and integrated for producing high frequency nanotube array ultrasonic transducers for high resolution ultrasonic imaging. We find that the nanotube structural feature and the unique nanoconfinement-induced crystal and polarization orientation lead to outstanding piezoelectric material properties and the resulting superior transducer performance. The nanotube array ultrasonic transducers show a broad bandwidth of 126 % (-6 dB) at 108 MHz, with significantly improved sensitivity in comparison with conventional thin film transducers despite the size shrinkage. We further demonstrate high resolution scanning ultrasonic imaging and photoacoustic imaging using the obtained nanotube array transducers, exhibiting great application values.

    关键词: piezoelectric nanotubes,high resolution imaging,ultrasonic transducers,photoacoustic imaging

    更新于2025-09-04 15:30:14