High Temporal‐Resolution Imaging Single Immune Cell Migration in Vivo by Ultrabright NIR‐II Organic Probes

in aqueous solution), enabling non-invasive high-speed single immune cell imaging in the brain with a temporal resolution up to ∼50 fps. The neutrophil migration patterns in the stroke mouse brain and their interactions with infused therapeutic mesenchymal stem cells can be profiled with real temporal dynamics. This advancement facilitates fundamental studies on understanding complex cellular functions in vivo, paving the way for investigating the effect of single-cell temporal dynamics on immune responses or disease-related biological processes.