Search

There has been no report on enzyme-controlled disassembly of self-quenched NIR fluorescent nanoparticles turning fluorescence on for specific detection/imaging of the enzyme's activity in vitro and in vivo. Herein, we reported the rational design of new NIR probe 1 whose fluorescence signal was self-quenched upon reduction-controlled condensation and subsequent assembly of its nanoparticles (i.e., 1-NPs). Then disassembly of 1-NPs by furin turned the fluorescence on. Employing this enzymatic strategy, we successfully applied 1-NPs for NIR detection of furin in vitro and NIR imaging furin activity in living cells. Moreover, we also applied 1-NPs for discriminative NIR imaging of MDA-MB-468 tumors in nude mice. This NIR probe 1 might be further developed for tumor-targeted imaging in routine preclinical studies or even in patients in the future.

We report herein the facile surface-functionalization of one type of biocompatible, oligomeric nanoparticles 1-NPs with NIR-emitting CdTe/CdS QDs and folate for tumor-targeted imaging in vivo. The -NH2 and -SH groups of cysteine residues on the 1-NPs were utilized to covalently conjugate CdTe/CdS QDs and Mal-FA to prepare the hybrid nanoparticles 1-NPs-QDs-FA. As-prepared 1-NPs-QDs-FA showed NIR-fluorescence emission at 734 nm, selective uptake by FR-overexpressing tumor cells in vitro, and selective FR-overexpressing tumor-targeted imaging in vivo. This first example of oligomeric/inorganic hybrid nanoparticles provides people with new type of biomaterials for tumor-targeted imaging with high selectivity., (Copyright © 2014 Elsevier Ltd. All rights reserved.)