nn8b03862_si_004.avi (24.68 MB)
Gold Nanoprisms as Optical Coherence Tomography Contrast Agents in the Second Near-Infrared Window for Enhanced Angiography in Live Animals
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posted on 2018-11-13, 00:00 authored by Peng Si, Edwin Yuan, Orly Liba, Yonatan Winetraub, Siavash Yousefi, Elliott Daniel SoRelle, Derek William Yecies, Rebecca Dutta, Adam de la ZerdaOptical 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 make 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. With GNPRs as contrast agents, the postinjection OCT angiograms
showed 41 and 59% more microvasculature than preinjection 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.