NIR-II fluorescence microscopic imaging of cortical vasculature in non-human primates

Abstract

Vasculature architecture in the brain can provide revealing information about mental and neurological function and disease. Fluorescence imaging in the second near-infrared (NIR-II) regime with less light scattering is a more promising method for detecting cortical vessels than traditional visible and NIR-I modes. Here, for the first time, we developed, NIR-II fluorescence microscopy capabilities for imaging brain vasculature in macaque monkey. The first is a wide-field microscope with high temporal resolution (25 frames/second) for measuring blood flow velocity and cardiac impulse period, and the second is a high spatial resolution (<10 μm) confocal microscope producing three-dimensional maps of the cortical microvascular network (~500 μm deep). Both were designed with flexibility to image various cortical locations on the head. Use of a clinically approved dye provided high brightness in NIR-II region. This comprises an important advance towards studies of neurovascular coupling, stroke, and other diseases relevant to neurovascular health in humans.

Enhancement of cerebrospinal fluid tracer movement by the application of pulsed transcranial focused ultrasound

“…The PFA perfusion fixation, uniformly adopted across the experimental conditions, would not have impacted the interpretation of the results, but may have reduced the observed fluorescence level in the brain tissue. Use of imaging techniques such as in vivo two-photon microscopy 18 or infrared confocal fluorescence imaging 54 would be helpful to monitor CSF tracer movement in live animals as well as to probe the contribution from potential expansion of the extracellular and perivascular space that may accompany pulsed application of ultrasound 55 .…”

Biologically excretable AIE dots for visualizing through the marmosets intravitally: horizons in future clinical nanomedicine

“…Importantly, the biosafety concerns for non-human primates should also been taken into serious consideration, which could be of vital importance for further clinical application. Recently, clinically approved indocyanine green assisted NIR-II fluorescence imaging has been successfully conducted in macaque monkeys 54 . Hence, longer emission wavelength, brighter emission intensity and biological excretion constitute the three harsh demand for new AIE dots especially for imaging performed at non-human primate models.…”

NIR-II imaging-guided diagnosis and evaluation of the therapeutic effect on acute alcoholic liver injuryviaa nanoprobe

“…So, blood ow velocity could probably act as a helpful biological index for AALI. [52][53][54][55] Herein, the NIR-II organic molecule TPB was formulated into nanoparticles (NPs) through the encapsulation of amphiphilic polymer DSPE-PEG-2000, and the NIR-II nanoprobe, NTPB-NPs, was obtained, demonstrating excellent biocompatibility, superior photostability and renal clearance. NTPB-NPs was used to visualize the liver injury of a mouse and to assess the treatment effect of silymarin (SILY) on AALI.…”