Pluronic F127–folic acid encapsulated nanoparticles with aggregation-induced emission characteristics for targeted cellular imaging

Abstract

In this work, fluorescence amplified organic nanoparticles (NPs) are synthesized by incorporation of the hydrophobic aggregation-induced emission (AIE) fluorophores, 9,10-bis(4-butoxystyryl) anthracene (BOSA) and/or bis(4-(N-(2-naphthyl)phenylamino)-phenyl)fumaronitrile (NPAPF), using biocompatible Pluronic F127–folic acid adduct (F127–FA) as the encapsulation matrix. The emission spectrum of BOSA donor overlaps well with the absorption spectrum of NPAPF acceptor, resulting in a 3.0-fold amplified NPAPF emission signal via fluorescence resonance energy transfer (FRET). The obtained BOSA–NPAPF co-loaded F127–FA nanoparticles (NPs) show a large Stokes shift of 245 nm, high water dispersibility, and low cytotoxicity. Application of these NPs for targeted cellular imaging is successfully demonstrated using folate receptor (FR)-overexpressed MCF-7 breast cancer cells as an example. Using the F127–FA as the encapsulation matrix, the folate-functionalized AIE NPs show bright fluorescence signals and specific targeting effect for FR-overexpressed cancer cells. These studies indicate that the F127–FA encapsulated AIE NPs are efficient fluorescent probes for biological imaging.