scholarly journals Gold Nanoprisms as Optical Coherence Tomography Contrast Agents in the Second Near-Infrared Window for Enhanced Angiography in Live Animals

ACS Nano ◽  
2018 ◽  
Vol 12 (12) ◽  
pp. 11986-11994 ◽  
Author(s):  
Peng Si ◽  
Edwin Yuan ◽  
Orly Liba ◽  
Yonatan Winetraub ◽  
Siavash Yousefi ◽  
...  
2018 ◽  
Author(s):  
Peng Si ◽  
Edwin Yuan ◽  
Orly Liba ◽  
Yonatan Winetraub ◽  
Siavash Yousefi ◽  
...  

ABSTRACTOptical coherence tomography angiography (OCTA) is an important tool for investigating vascular networks and microcirculation in living tissue. Traditional OCTA detects blood vessels via intravascular dynamic scattering signals derived from the movements of red blood cells (RBCs). However, the low hematocrit and long latency between RBCs in capillaries makes these OCTA signals discontinuous, leading to incomplete mapping of the vascular networks. OCTA imaging of microvascular circulation is particularly challenging in tumors due to the abnormally slow blood flow in angiogenic tumor vessels and strong attenuation of light by tumor tissue. Here we demonstrate in vivo that gold nanoprisms (GNPRs) can be used as OCT contrast agents working in the second near infrared window, significantly enhancing the dynamic scattering signals in microvessels and improving the sensitivity of OCTA in skin tissue and melanoma tumors in live mice. This is the first demonstration that nanoparticle-based OCT contrast agent work in vivo in the second near infrared window, which allows deeper imaging depth by OCT. With GNPRs as contrast agents, the post-injection OCT angiograms showed 41% and 59% more microvasculature than pre-injection angiograms in healthy mouse skin and melanoma tumors, respectively. By enabling better characterization of microvascular circulation in vivo, GNPR-enhanced OCTA could lead to better understanding of vascular functions during pathological conditions, more accurate measurements of therapeutic response, and improved patient prognoses.


Nano Letters ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Peng Si ◽  
Saba Shevidi ◽  
Edwin Yuan ◽  
Ke Yuan ◽  
Ziv Lautman ◽  
...  

2019 ◽  
Author(s):  
Peng Si ◽  
Saba Shevidi ◽  
Edwin Yuan ◽  
Ke Yuan ◽  
Ziv Lautman ◽  
...  

AbstractDeveloping contrast-enhanced optical coherence tomography (OCT) techniques is important for specific imaging of tissue lesions, molecular imaging, cell-tracking, and highly sensitive microangiography and lymphangiography. Multiplexed OCT imaging in the second near infrared (NIR-II) window is highly desirable since it allows simultaneous imaging and tracking of multiple biological events in high resolution with deeper tissue penetration in vivo. Here we demonstrate that gold nanobipyramids can function as OCT multiplexing contrast agents, allowing the visualization of two separate lymphatic flows occurring simultaneously from different drainage basins into the same lymph node in a live mouse. Contrast-enhanced multiplexed lymphangiography of a melanoma tumor in vivo shows that the peritumoral lymphatic drainage upstream of the tumor is unidirectional, with some drainage directly into the tumor, but the lymphatic drainage from the tumor is multi-directional. We also demonstrate real-time tracking of the contrast agents draining from a melanoma tumor specifically to the sentinel lymph node of the tumor and the three-dimensional distribution of the contrast agents in the lymph node.


2021 ◽  
Vol 127 (4) ◽  
Author(s):  
S. Skruszewicz ◽  
S. Fuchs ◽  
J. J. Abel ◽  
J. Nathanael ◽  
J. Reinhard ◽  
...  

AbstractWe present an overview of recent results on optical coherence tomography with the use of extreme ultraviolet and soft X-ray radiation (XCT). XCT is a cross-sectional imaging method that has emerged as a derivative of optical coherence tomography (OCT). In contrast to OCT, which typically uses near-infrared light, XCT utilizes broad bandwidth extreme ultraviolet (XUV) and soft X-ray (SXR) radiation (Fuchs et al in Sci Rep 6:20658, 2016). As in OCT, XCT’s axial resolution only scales with the coherence length of the light source. Thus, an axial resolution down to the nanometer range can be achieved. This is an improvement of up to three orders of magnitude in comparison to OCT. XCT measures the reflected spectrum in a common-path interferometric setup to retrieve the axial structure of nanometer-sized samples. The technique has been demonstrated with broad bandwidth XUV/SXR radiation from synchrotron facilities and recently with compact laboratory-based laser-driven sources. Axial resolutions down to 2.2 nm have been achieved experimentally. XCT has potential applications in three-dimensional imaging of silicon-based semiconductors, lithography masks, and layered structures like XUV mirrors and solar cells.


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