Multifunctional in vivo vascular imaging using near-infrared II fluorescence

Abstract

In vivo real-time epifluorescence imaging of mouse hindlimb vasculatures in the second near-infrared region (NIR-II, 1.1–1.4 µm) is performed using single-walled carbon nanotubes (SWNTs) as fluorophores. Both high spatial resolution (~30 µm) and temporal resolution (<200 ms/frame) for small vessel imaging are achieved 1~3 mm deep in the tissue owing to the beneficial NIR-II optical window that affords deep anatomical penetration and low scattering. This spatial resolution is unattainable by traditional NIR imaging (NIR-I, 0.75–0.9 µm) or microscopic computed tomography (micro-CT), while the temporal resolution far exceeds scanning microscopic imaging techniques. Arterial and venous vessels are unambiguously differentiated using a dynamic contrast-enhanced NIR-II imaging technique based on their distinct hemodynamics. Further, the deep tissue penetration, high spatial and temporal resolution of NIR-II imaging allow for precise quantifications of blood velocity in both normal and ischemic femoral arteries, which are beyond the capability of ultrasonography at lower blood velocity.

Thermally Activated Delayed Fluorescence Organic Dots (TADF Odots) for Time‐Resolved and Confocal Fluorescence Imaging in Living Cells and In Vivo

“…Fluorescence imaging has been demonstrated as an indispensable and versatile tool in tracking and understanding complex biological environments both in vivo and in vitro 1, 2. Compared to other imaging modalities, fluorescence imaging offers high spatiotemporal resolution as a noninvasive technique 1, 2, 3.…”

“…Compared to other imaging modalities, fluorescence imaging offers high spatiotemporal resolution as a noninvasive technique 1, 2, 3. It can probe the deeper layers of a specimen at ambient conditions and also enable spectroscopic diagnosis with chemical sensitivity 4.…”

Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects

“…A natural strategy to fulfil the property (i) is to use group-IV (carbon and silicon) nanomaterials. Indeed, carbon nanotubes (from 1.8 µm down to 50 nm in length) have been applied for deep-tissue imaging 15,16 because of their NIR PL in the spectral range from 900 nm to 1500 nm.…”

Graphene-Based Nanomaterials in Bioimaging

“…Their quantum yield (QY) is in the range of 0.02-70.3% (119)(120)(121). However, reduced GO shows a strong photoluminescence quenching effect with enhanced absorbance in the NIR region (12), unlike single-walled carbon nanotubes (SWNTs), which has unique photoluminescence in both NIR-I (700-900 nm) and NIR-II (1100-1400 nm) regions (122)(123)(124).…”