PPV-Based Conjugated Polymer Nanoparticles as a Versatile Bioimaging Probe: A Closer Look at the Inherent Optical Properties and Nanoparticle–Cell Interactions

Abstract

Conjugated polymers have attracted significant interest in the bioimaging field due to their excellent optical properties and biocompatibility. Tailor-made poly(p-phenylenevinylene) (PPV) conjugated polymer nanoparticles (NPs) are in here described. Two different nanoparticle systems using poly[2-methoxy-5-(3',7'-dimethoxyoctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and a functional statistical copolymer 2-(5'-methoxycarbonylpentyloxy)-5-methoxy-1,4-phenylenevinylene (CPM-MDMO-PPV), containing ester groups on the alkoxy side chains, were synthesized by combining miniemulsion and solvent evaporation processes. The hydrolysis of ester groups into carboxylic acid groups on the CPM-MDMO-PPV NPs surface allows for biomolecule conjugation. The NPs exhibited excellent optical properties with a high fluorescent brightness and photostability. The NPs were in vitro tested as potential fluorescent nanoprobes for studying cell populations within the central nervous system. The cell studies demonstrated biocompatibility and surface charge dependent cellular uptake of the NPs. This study highlights that PPV-derivative based particles are a promising bioimaging probe and can cater potential applications in the field of nanomedicine.

Recent Advances in the Development of Highly Luminescent Semiconducting Polymer Dots and Nanoparticles for Biological Imaging and Medicine

“…61 Fundamental studies of Pdots and CPNs, especially their photophysical properties, are also ongoing, including recent reports by the McNeill group 119–122 and by other research groups. 94,123–125 There have also been many reports on the development and application of different Pdots and CPNs as imaging or tracking probes. 27,78,94,109,125–130 …”

“…94,123–125 There have also been many reports on the development and application of different Pdots and CPNs as imaging or tracking probes. 27,78,94,109,125–130 …”

The Photophysics of Polythiophene Nanoparticles for Biological Applications

“…Although the interfaces in these scenarios are extended surfaces over millimeter‐length scales, the scaling down of such interfaces to smaller particles should bring advantages such as easy delivery and closer interaction with cells and organelles: characteristics that enhance and extend the range of possible applications. Moreover, colloidal suspensions of NPs of hundreds of nanometers in dimensions can easily be fabricated, particularly in aqueous solutions, thus making them biocompatible . In fact, the biocompatibility of P3HT NPs has already been established, as well as the possibility of using them as bio‐organic interfaces both for sensing and as actuators .…”

A Simple and Versatile Pathway for the Synthesis of Visible Light Photoreactive Nanoparticles

“…The use of organic fluorescent dyes is an alternative approach to impart fluorescence onto a particle system; however, most current generation dyes undergo photobleaching over time . The use of conjugated materials is an attractive tool to design inherently fluorescent nanoparticles, but the synthesis process is tedious and can be time consuming …”