Organic NIR-II molecule with long blood half-life for in vivo dynamic vascular imaging

TLDR

Real‑time monitoring of vessel dysfunction is crucial, yet existing NIR‑II dyes are limited by short circulation times and sub‑1000‑nm absorption/emission, hindering long‑term imaging. The authors introduce LZ‑1105, a NIR‑II fluorophore with absorption and emission wavelengths beyond 1000 nm. LZ‑1105 was engineered to possess a long blood half‑life of 3.2 h, enabling sustained vascular imaging. Using LZ‑1105, the study achieved continuous real‑time monitoring of dynamic vascular events such as hindlimb ischemia reperfusion, carotid thrombolysis, and blood‑brain‑barrier opening/recovery, demonstrating its utility for assessing vessel dysfunction.

Abstract

Real-time monitoring of vessel dysfunction is of great significance in preclinical research. Optical bioimaging in the second near-infrared (NIR-II) window provides advantages including high resolution and fast feedback. However, the reported molecular dyes are hampered by limited blood circulation time (~ 5-60 min) and short absorption and emission wavelength, which impede the accurate long-term monitoring. Here, we report a NIR-II molecule (LZ-1105) with absorption and emission beyond 1000 nm. Thanks to the long blood circulation time (half-life of 3.2 h), the fluorophore is used for continuous real-time monitoring of dynamic vascular processes, including ischemic reperfusion in hindlimbs, thrombolysis in carotid artery and opening and recovery of the blood brain barrier (BBB). LZ-1105 provides an approach for researchers to assess vessel dysfunction due to the long excitation and emission wavelength and long-term blood circulation properties.