Carboxylesterase-Cleavable Biotinylated Nanoparticle for Tumor-Dual Targeted Imaging.

Near-infrared (NIR) nanoprobes with fluorescence "Turn-On" property are advantageous in cancer diagnosis but, to the best of our knowledge, "smart" nanoprobe that simultaneously targets both biotin receptor and carboxylesterase (CES) for HepG2 tumor-dual targeted imaging has not been reported. Methods : Using CBT-Cys click condensation reaction, we rationally designed a "smart" NIR fluorescence probe H ₂ N-Cys(StBu)-Lys(Biotin)-Ser(Cy5.5)-CBT ( NIR-CBT ) and used it to facilely prepare the fluorescence-quenched nanoparticle NIR-CBT-NP . Results : In vitro results indicated that, after NIR-CBT-NP was incubated with CES for 6 h, its fluorescence was turned "On" by 69 folds. Cell experiments verified that NIR-CBT-NP was uptaken by HepG2 cells via biotin receptor-assisted endocytosis and its fluorescence was turned "On" by intracellular CES hydrolysis. Moreover, NIR-CBT-NP was successfully applied to image both biotin receptor- and CES-overexpressing HepG2 tumors. Conclusion : Fluorescence-quenched nanoparticle NIR-CBT-NP was facilely prepared to actively target biotin receptor-overexpressing HepG2 cancer cells and turn the fluorescence "On" by intracellular CES hydrolysis for tumor-dual targeted imaging. We anticipate that our fluorescence "Turn-On" nanoparticle could be applied for liver cancer diagnosis in clinic in the near future.
Competing Interests: Competing Interests: The authors have declared that no competing interest exists.
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