PhotoATRP-Induced Self-Assembly (PhotoATR-PISA) Enables Simplified Synthesis of Responsive Polymer Nanoparticles in One-Pot

Photo-controlled atom transfer radical polymerization (PhotoATRP) was implemented, for the first time, to accomplish polymerization-induced self-assembly (PISA) mediated by UV light (λ = 365 nm) using parts per million (ppm) levels (ca. <20 ppm) of a copper catalyst at ambient temperature. Using CuIIBr2/tris(pyridin-2-ylmethyl)amine (TPMA) catalyst systems, PISA was performed all in one-pot starting from the synthesis of solvophilic poly(oligo(ethylene oxide) methyl ether methacrylate) (POEGMA) blocks to core-cross-linked nanoparticles (NPs) utilizing poly(glycidyl methacrylate) (PGMA) and N,N-cystamine bismethacrylamide (CBMA) as the solvophobic copolymer and cross-linking agent, respectively. Sequential chain-extensions were performed for PGMA demonstrating capabilities for accessing multifunctional copolymer NPs with temporal control via switching the UV light on and off. Further, core cross-linking of PISA NPs was performed via the slower incorporation of the CBMA enabling one-pot cross-linking during the PISA process. Finally, the disulfide installed in the CBMA core cross-links allowed for the stimulus-triggered dissociation of nanoparticles using DL-dithiothreitol at acidic pH.