Development of Biocompatible Quantum Dots using Zwitterionic Copolymer for Biological Application

Abstract

In recent years, zwitterionic polymers has been extensively studied because of their unique water-stability and highly efficient non-biofouling property. This work describes a new class of polymeric ligands for quantum Dot (QD), QDs coated short-chain zwitterionic ligand were stabilized against aggregation from proteins. The zwitterionic polymers are synthesized by reversible addition-fragmentation chain transfer-mediated polymerization to control the uniform molecular weight of random copolymer with histidine group for binding QD surface, and (3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide (MPDSAH) group for water solubilization, and primary amine group as binding site for derivatization. Then by carefully handling primary amine of surface, folate-conjugated QDs (QD-FAs) with high photostability are prepared. We demonstrate receptor-mediated conjugation of folic acid functionalized QDs on live cell lines such as Hela cells.