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

Superb reliability and biocompatibility equip aggregation-induced emission (AIE) dots with tremendous potential for fluorescence bioimaging. However, there is still a chronic lack of design instructions of excretable and bright AIE emitters. Here, we designed a kind of PEGylated AIE (OTPA-BBT) dots with strong absorption and extremely high NIR-II PLQY as 13.6%, and proposed the long-aliphatic-chain design blueprint contributing to their excretion from animal body. Assisted by the OTPA-BBT dots with bright fluorescence beyond 1100 nm and even 1500 nm (NIR-IIb), large-depth cerebral vasculature (beyond 600 μm) as well as real-time blood flowing were monitored through-thinned-skull, and noninvasive NIR-IIb imaging with rich high-spatial-frequency information gave a precise presentation of gastrointestinal tract in marmosets. Importantly, after intravenous or oral administration, the definite excretion of OTPA-BBT dots from the body was demonstrated, which showed an influential evidence of bio-safety.