Synthesis and pH/sugar/salt-sensitivity study of boronate crosslinked glycopolymer nanoparticles

Abstract

Poly(3-methacrylamido phenylboronic acid) (PMAPBA) homopolymer and poly(ethylene glycol)-block-poly(2-acryloxyethyl-galactose) (PEG-b-PAEG) glycopolymer were prepared successfully by reversible addition fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP), respectively. The formation of boronate crosslinked nanoparticles based on the complexation of PMAPBA and PEG-b-PAEG was confirmed by dynamic light scattering (DLS), thermal analysis, and Alizarin red S (ARS) based colorimetric and fluorescence assays. The nanoparticles showed significant pH, salt, and sugar sensitivity. At pH 5.0 and 6.0, the aggregation and precipitation of the nanoparticles were observed. The particle size increased significantly as pH increased from 7 to 11. The nanoparticles showed obvious sensitivity to glucose, galactose, mannose, and sucrose at pH 10. Due to shielding of the negatively charged phenylboronic acid groups, the aggregation of the boronate crosslinked nanoparticles was found with increase of the salt concentration.