Specific two-photon imaging of live cellular and deep-tissue lipid droplets by lipophilic AIEgens at ultra-low concentration
journal contributionposted on 17.07.2018 by Guangle Niu, Ruoyao Zhang, John P. Kwong, Jacky W.Y. Lam, Congping Chen, Jianguo Wang, Yuncong Chen, Xing Feng, Ryan T. Kwok, Herman H.-Y. Sung, Ian D. Williams, Mark Elsegood, Jianan Qu, Chao Ma, Kam S. Wong, Xiaoqiang Yu, Ben Zhong Tang
Any type of content formally published in an academic journal, usually following a peer-review process.
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.
This work was partially supported by the National Natural Science Foundation of China (21788102, 51773111, 21490570, and 21490574), the National Basic Research Program of China (973 Program: 2013CB834701 and 2013CB834702), the Research Grants Council of Hong Kong (16301614, 16305015, A-HKUST 605/16, N_HKUST604/14, and AoE/P-02/12), the Innovation and Technology Commission (ITC-CNERC14SC01 and ITCPD/17-9), and the Science and Technology Plan of Shenzhen (JCYJ20170818113851132, JCYJ20170818113840164, JCYJ20160229205601482, and JCYJ20140425170011516).