One-step preparation of AIE-active dextran via formation of phenyl borate and their bioimaging application

Abstract

The fabrication of luminescent polymeric nanoparticles with aggregation induced emission (AIE) properties has been extensively investigated in recent years for their distinct optical properties, biocompatibility and designability. Although a number of AIE-active nanoparticles have been fabricated previously, the AIE-active nanoprobes based on carbohydrate polymers have received only limited attention. In this work, we reported for the first time that AIE-active organic nanoparticles could be prepared via a facile one-step strategy. To fabricate these AIE-active nanoparticles, the AIE dye 9,10-bis (divinylphenylboronic acid) anthracene (An-B(OH)2) terminated with phenylboronic acid was synthesized using anthracene as core chemical structure. After mixing with the An-B(OH)2 and dextran, the resultant products (An-Dex) can be obtained through formation of phenyl borate in aqueous solution, air atmosphere and under room temperature. The intermediates and An-Dex were characterized by a series of characterization techniques including 1H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and fluorescence spectroscopy. To further explore the biomedical applications of these glycosylated AIE-active nanoparticles, cell viability as well as cell imaging performance of An-Dex nanoparticles was also examined. We demonstrated that An-Dex nanoparticles showed strong fluorescent intensity, great water dispersibility and excellent biocompatibility. More importantly, it is well known that phenyl borate is a dynamic bond, which can potentially response to the pH and glucose. Therefore, the resultant AIE-active probes should be promising candidates for different biomedical applications such as biological imaging and controlled drug delivery.