PEG-based core-degradable nanoparticles via RAFT-mediated reverse-sequence PISA

Abstract

We report in this study the synthesis of core-degradable spherical nanoparticles via reverse-sequence polymerization-induced self-assembly (PISA) under aqueous conditions. A hydrophobic poly[(ethylene carbonate)-co-(ethylene oxide)] (PECEO) copolymer sample was utilized to synthesize the PECEO macro chain-transfer agent (PECEO macro-CTA), which was subsequently chain-extended with N,N′-dimethylacrylamide (DMAA) via reversible addition–fragmentation chain transfer (RAFT) polymerization, leading to the formation of stable spherical nanoparticles. In all cases, near-quantitative monomer conversion was achieved, as confirmed by ¹H NMR spectroscopy. Dynamic light scattering (DLS) analysis confirmed the formation of spherical nanoparticles with diameters in the 20–30 nm range. The incorporation of carbonate units within the polymer backbone conferred degradability to the nanoparticle, as further demonstrated by size exclusion chromatography (SEC) and ¹H NMR analyses when those nanoparticle suspensions were subjected to basic conditions.