Aggregation-induced emission (AIE) has captured immense attention in recent years. Previous studies reveal that there exists much scope for improvement in imaging quality beyond 900 nm or even 1500 nm compared to the traditional first near-infrared region (NIR-I) fluorescence imaging (760-900 nm). Given the suppressed tissue-scattering and diminished autofluorescence, fluorescence bioimaging in the second near-infrared region (NIR-II, 900-1700 nm) allows the precise visualization of details throughout some thick tissues in mammals with high signal-to-background ratio and sharp spatial resolution. Nowadays, biological excretion, long emission wavelength and high emission intensity have constituted the three harsh demands for new AIE dots, especially for imaging performed on primate models. Moreover, bioimaging of non-human primates is also the key to the clinical utilization of AIE dots.
Through‐thinned‐skull cerebrovascular microscopy imaging with high spatial‐resolution
Using fluorescence resonance energy transfer (FRET) technology, Prof. QIAN Jun’s team at the Zhejiang University College of Optical Science and Engineering observed that AIE molecules with long lipid chains were more likely to be released from PEGylated micelles with the influence of biological protein and further excreted from the animal body. With the joint efforts of Prof. QIAN Jun, Prof. GAO Lixia at the Zhejiang University School of Medicine and Prof. TANG Ben Zhong at the Hong Kong University of Science and Technology, researchers developed a kind of AIE fluorescence dots for large-depth cerebral vasculature as well as real-time blood flow through a thinned skull. Non-invasive NIR-IIb imaging with rich high-spatial-frequency information gives a precise presentation of gastrointestinal tract in marmosets. The AIE dot will provide a novel approach to disease diagnosis. This study was recently published in Advanced Materials.
NIR‐IIb fluorescence noninvasive gastrointestinal imaging with high spatial‐frequency
This study takes the lead in developing an effective design based on biologically excretable AIE dots. This type of AIE dots can be applied to marmoset fluorescence imaging. It is for the first time that researchers have performed through-thinned-skull cortical vasculature imaging and NIR-IIb fluorescence GI imaging in non-human primates. “This study is expected to guide the design of next-generation AIEgens and promote the development of AIEgens in clinical practices,” said QIAN Jun.