AUTHOR=Gao Yong-Guang , Liu Fen-Li , Patil Suryaji , Li Di-Jie , Qadir Abdul , Lin Xiao , Tian Ye , Li Yu , Qian Ai-Rong 

TITLE=1,8-Naphthalimide-Based Multifunctional Compounds as Cu2+ Probes, Lysosome Staining Agents, and Non-viral Vectors

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00616

DOI=10.3389/fchem.2019.00616

ISSN=2296-2646

ABSTRACT=<p>A series of multifunctional compounds (MFCs) <bold>1a</bold>–<bold>1d</bold> based on 1,8-naphthalimide moiety were designed and synthesized. Due to the good fluorescence property and nucleic acid binding ability of 1,8-naphthalimide, these MFCs were applied in Cu<sup>2+</sup> ion recognition, lysosome staining as well as RNA delivery. It was found that these MFCs exhibited highly selective fluorescence turn-off for Cu<sup>2+</sup> in aqueous solution. The fluorescence emission of <bold>1a−1d</bold> was quenched by a factor of 116-, 20-, 12-, and 14-fold in the presence of Cu<sup>2+</sup> ions, respectively. Most importantly, <bold>1a</bold>-Cu and <bold>1b</bold>-Cu could be used as imaging reagents for detection of lysosome in live human cervical cancer cells (HeLa) using fluorescence microscopy. Furthermore, in order to evaluate the RNA delivery ability of <bold>1a−1d</bold>, cellular uptake experiments were performed in HeLa, HepG2, U2Os, and MC3T3-E1 cell lines. The results showed that all the materials could deliver Cy5-labled RNA into the targeted cells. Among them, compound <bold>1d</bold> modified with long hydrophobic chain exhibited the best RNA delivery efficiency in the four tested cell lines, and the performance was far better than lipofectamine 2000 and 25 kDa PEI, indicating the potential application in non-viral vectors.</p>