2134/33947 Guangle Niu Guangle Niu Ruoyao Zhang Ruoyao Zhang John P. Kwong John P. Kwong Jacky W.Y. Lam Jacky W.Y. Lam Congping Chen Congping Chen Jianguo Wang Jianguo Wang Yuncong Chen Yuncong Chen Xing Feng Xing Feng Ryan T. Kwok Ryan T. Kwok Herman H.-Y. Sung Herman H.-Y. Sung Ian D. Williams Ian D. Williams Mark Elsegood Mark Elsegood Jianan Qu Jianan Qu Chao Ma Chao Ma Kam S. Wong Kam S. Wong Xiaoqiang Yu Xiaoqiang Yu Ben Zhong Tang Ben Zhong Tang Specific two-photon imaging of live cellular and deep-tissue lipid droplets by lipophilic AIEgens at ultra-low concentration Loughborough University 2018 untagged Chemical Sciences not elsewhere classified 2018-07-17 09:58:47 Journal contribution https://repository.lboro.ac.uk/articles/journal_contribution/Specific_two-photon_imaging_of_live_cellular_and_deep-tissue_lipid_droplets_by_lipophilic_AIEgens_at_ultra-low_concentration/9393311 Lipid droplets are highly associated with obesity, diabetes, inflammatory disorders and cancer. A reliable two-photon dye for specific lipid droplets imaging in live cells and live tissues at ultra-low concentration has rarely been reported. In this work, four new aggregation-induced emission luminogens (AIEgens) based on the naphthalene core were designed and synthesized for specific two-photon lipid droplets staining. The new molecules, namely NAP AIEgens, exhibit large Stokes shift (>110 nm), high solid-state fluorescence quantum yield (up to 30%), good two-photon absorption cross section (45–100 GM at 860 nm), high biocompatibility and good photostability. They could specifically stain lipid droplets at ultra-low concentration (50 nM) in a short time of 15 min. Such ultra-low concentration is the lowest value for lipid droplets staining in live cells reported so far. In vitro and ex vivo two-photon imaging of lipid droplets in live cells and live mice liver tissues were successfully demonstrated. In addition, selective visualization of lipid droplets in live mice liver tissues could be achieved at a depth of about 70 μm. These excellent properties render them as promising candidates for investigating lipid droplets-associated physiological and pathological processes in live biological samples.