Fluorescein Derivative Monomer for the Production of Fluorescent Latex Particles

Abstract

The use of fluorescent polymeric particles as a tool for microscopy imaging or flux cytometry is an excellent choice for diagnosis, research and development. They are suitable for complexes formation with several biological molecules and macromolecules. A simple and cost-effective method is here proposed to produce fluorescent latex particles (FLP). To this effect, the synthesis of a fluorescent monomer, capable of being copolymerized with vinyl monomers, was achieved by reaction between fluorescein and glycidyl methacrylate, and monitored by UV-Vis, IR, NMR and Fluorescence spectrometry. The synthesis of fluorescent particles was carried out by emulsion copolymerization of styrene, methacrylic acid and the fluorescent monomer. Latexes were characterized by measuring styrene/methacrylic acid conversion, average particle diameter, fluorescence, surface charge and group density. Conversion reached nearly 90 %, and negatively charged particles of 130-260nm were obtained, which proved to have high fluorescence with an emission maximum at 511nm. Cell fluorescent staining was carried out using the obtained particles. Observation of the FLP-treated cells by confocal microscopy exhibited intense fluorescence within all the internal media, with a fluorescein like emission pattern. The production of stable fluorescent particles, with controlled size and high fluorescein incorporation, capable of interacting with proteins and cells efficiently, was confirmed.