Glycosylated polyacrylate nanoparticles by emulsion polymerization

Abstract

A selection of glycosylated polyacrylate nanoparticles has been prepared by radical-initiated emulsion polymerization in aqueous media. Using ethyl acrylate as a co-monomer, carbohydrate acrylates were incorporated into the poly(ethyl acrylate) framework to give stable emulsions of glyconanoparticles with an average particle size of around 40 nm. Using this technique a variety of glyconanoparticles were prepared from 3- O-acryloyl-1,2:5,6-di- O-isopropylidene-α- d-glucofuranose, 1- O-acryloyl-2,3:5,6-di- O-isopropylidene-α- d- mannofuranose, 6- O-acryloyl-1,2:3,4-di- O-isopropylidene-α- d-galactopyranose, 2- N-acryloyl-1,3,4,6-tetra- O-acetyl-β- d-glucosamine, 5- O-acryloyl-2,3-isopropylidene-1-methoxy-β- d-ribofuranose and 4- N-acetyl-5′- O-acryloyl-2′,3′- O-isopropylidene cytidine. Scanning electron microscopy, dynamic light scattering and proton NMR analysis of the emulsions indicated essentially 100% incorporation of the carbohydrate acrylate monomer into the polymer with the exception of O-benzyl- and O-benzoyl-protected carbohydrate acrylates, which gave incomplete incorporation. Formation of larger glyconanoparticles of ∼80 nm with (unprotected) 3- O-acryloyl- d-glucose and 5- O-acryloyl-1-methoxy-β- d-ribofuranose revealed the influence of free hydroxyl groups in the monomer on the particle size during polymerization, a feature which is also apparently dependent on the amount of carbohydrate in the matrix. This methodology allows for a new, simple route to the synthesis of polymeric glyconanoparticles with potential applications in targeted drug delivery and materials development.