PEGylated Fluorescent Nanoparticles from One-Pot Atom Transfer Radical Polymerization and "Click Chemistry"

The preparation of PEGylated fluorescent nanoparticles (NPs) based on atom transfer radical polymerization (ATRP) and click chemistry in one-pot synthesis is presented. First, poly(p-chloromethyl styrene-alt-N-propargylmaleimide) (P(CMS-alt-NPM)) copolymer was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization. Subsequently, the azido-containing fluorene-based polymer, poly[(9,9-dihexylfluorene)-alt-(9,9-bis-(6-azidohexyl)fluorene)] (PFC6N(3)), was synthesized via Suzuki coupling polymerization, followed by azidation. Finally, the PEGylated fluorescent NPs were prepared via simultaneous intermolecular click cross-linking between P(CMS-alt-NPM) and PFC6N(3) and the ATRP of poly(ethylene glycol) methyl ether methacrylate (PEGMMA) using P(CMS-alt-NPM) as the macroinitiator. The low cytotoxicity of the PEGylated fluorescent NPs was revealed by incubation with KB cells, a cell line derived from carcinoma of the nasopharynx, in an in vitro experiment. The biocompatible PEGylated fluorescent NPs were further used as a labeling agent for KB cells.