N n dimethylaminoethyl methacrylate

Poly(ethylene glycol)s (PEG; M_n: 3900 and 11200) were kindly provided by NOF Corporation (Tokyo, Japan). 4-Cyano-4-(thiobenzoylthio)pentanoic acid (CTPA) and 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA) were purchased from Millipore Sigma (St. Louis, MO, USA). Dicyclohexylcarbodiimide (DCC), N,N-dimethylaminopyridine (DMAP), 2,2,2-trifluoroethanol (TFE), 1,4-butanesultone, 1,3,2-dioxathiane-2,2-dioxide, and N,N-dimethylaminopropyl methacrylate were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). 4,4’-Azobis (4-cyanovaleric acid) (ACVA) and N,N-dimethylaminoethyl methacrylate were purchased from FUJIFILM Wako Pure Chemical Corporation (Osaka, Japan). Phosphate-buffered saline (PBS(−)) was prepared by dissolving NaCl (4.0 g), KCl, (0.10 g), Na₂HPO₄·12H₂O (1.5 g), and KH₂PO₄ (0.10 g) into 500 mL of ultrapure water (Milli-Q, 18.2 MΩ·cm). All aqueous solutions were prepared using ultrapure water (Milli-Q, 18.2 MΩ·cm). Other solvents were obtained from commercial sources and used without purification.