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- 实验方案
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Long-distance tracing of the lymphatic system with a CT/fluorescence dual-modality nanoprobe for surveying tumor lymphatic metastasis
摘要: Noninvasive visualization of deep tissue lymphatic metastasis is crucial for diagnosing malignant tumors and predicting prognosis. However, the limited diffusivity and specificity of imaging contrast agents that are transported in lymph vessels (LVs), even for those agents delivered by nanocarriers, make long-distance tracing of the lymphatic system in vivo challenging. Here, we develop a CT/fluorescence dual-modality phospholipid nanoprobe (PL(I/D)NP) with a negative charge and sub-60 nm size. By using micro-CT, we noninvasively traced the LVs from the subcutaneous injection site in feet to the thoracic ducts with an entire length of ~68 mm and measured the volume of the lymph nodes (LNs) and their separation distance along the LVs. For diagnostic imaging of tumor lymphatic metastasis, all LNs with metastasis were identified in vivo. Thus, with their long-distance diffusivity, high lymphatic capillary specificity and quantifiability, the PL(I/D)NPs combined with noninvasive imaging accurately depicted the changes in the lymphatic system under pathologic conditions, especially cancer metastasis, which indicates their high potential for clinical applicability.
关键词: lymphatic system,nanoparticle,fluorescent imaging,micro-CT,lymphatic metastasis
更新于2025-11-21 11:08:12
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Probing Polarity and Heterogeneity of Lipid Droplets in Live Cells Using a Push–Pull Fluorophore
摘要: Lipid droplets (LDs) are organelles composed of a lipid core surrounded by a phospholipid monolayer. Lately, LDs attracted a considerable attention due to recent studies demonstrating their role in a variety of physiological processes as well as diseases. Herein we synthesized a push-pull molecule named DAF (Dimethyl Aniline Furaldehyde) that possesses a strong positive solvatochromism in emission of 119 nm from toluene to methanol. Its impressive fluorogenic properties from water to oil (2000-fold) as well as its high quantum yields (up to 0.97) led us to investigate its ability to sense the distribution of polarity in live cells by fluorescence ratiometric imaging. When added to live cells and excited at 405 nm, DAF immediately and brightly stain lipid droplets using a blue channel (410-500 nm) and cytoplasm in a red channel (500-600 nm). DAF also proved to be compatible with fixation thus allowing 3D imaging of LDs in their cytoplasm environment. Taking advantage of DAF emission in two distinct channels, ratiometric imaging was successfully performed and led to the polarity mapping of the cell unraveling some heterogeneity in polarity within LDs of the same cell.
关键词: Environment Sensitive Fluorescent Probe,Lipid Droplets,Ratiometric Imaging,Multicolor Fluorescent imaging
更新于2025-09-23 15:23:52
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Integration of fluorescence imaging and electrochemical biosensing for both qualitative location and quantitative detection of cancer cells
摘要: In this work, DNA-templated silver nanoclusters (DNA-AgNCs) with unique fluorescent and electrochemical properties are prepared as dual signal probes for both qualitative imaging and quantitative detection of cancer cells in an integrated system. ITO electrode that has good light transmittance and electric conductivity is employed as a substrate for dual analysis of cancer cells. ITO electrode is firstly modified by AS1141 aptamer, which could selectively bind to nucleolin overexpressed on the surface of a model breast cancer cell, MCF-7 cell line. The composite of mucin 1 antibody (anti-MUC1) and DNA-AgNCs then binds to MUC1 on the surface of captured MCF-7 cell, forming a sandwich-like structure. Therefore, our method allows noninvasive fluorescence imaging and amplified electrochemical detection using a single labeling platform, providing a biocompatible and highly specific method for adequate analysis of cancer cells. Experimental results demonstrate that strong red fluorescence of DNA-AgNCs clearly displays the loading of cancer cells on ITO electrode after dual recognition, and amplified electrochemical signals of DNA-AgNCs enable improved sensitivity toward quantitative analysis with a detection limit of 3 cells.
关键词: ITO electrode,DNA-templated silver nanoclusters,MCF-7 cell,fluorescent imaging,electrochemical detection
更新于2025-09-23 15:22:29
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[IEEE 2019 41st Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) - Berlin, Germany (2019.7.23-2019.7.27)] 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Ultrasonically Steerable Graded-Index Optical Waveguides for Deep Tissue Light Delivery: Theory and Applications
摘要: Graded-index (GRIN) fibers have been used as implantable optical waveguides to guide light and relay images through the depth of the tissue. We have recently shown that non-invasive ultrasound can generate refractive index gradients within the tissue that form virtual GRIN lenses for imaging and photostimulation deep into the tissue. Here we present the theory behind this idea by analyzing the coupled acoustic-photonic system that models the interaction of light with the ultrasonically modulated medium. We will discuss how changing the parameters of ultrasound will change the confinement and guiding of light within the modulated medium. We will also demonstrate that using a custom-designed cylindrical ultrasonic array, the pressure interference can be controlled to sculpt complex patterns of light in the medium, such as dipole and quadrupole shapes, suitable for multisite imaging. Finally, we will discuss experimental results corroborating the theoretical predictions to generate single and multisite in situ virtual lenses that can be used for fluorescent imaging of mouse brain tissue that expresses green fluorescent protein (GFP).
关键词: refractive index gradients,fluorescent imaging,Graded-index fibers,acousto-optic system,ultrasound,virtual GRIN lenses,photostimulation
更新于2025-09-12 10:27:22