2 bromoisobutyryl bromide

Monohydroxy-capped poly(ethylene glycol) (PEG₁₁₃-OH) with a mean degree of polymerization, DP, of 113 (M_n = 5000 g/mol, M_w/M_n = 1.02) was purchased from Aldrich and dried at 30 °C under vacuum overnight prior to use. 2-Diethylaminoethyl methacrylate (DEA, Aldrich, 99%) and styrene (St, Aldrich, 99%) were passed through basic alumina column to remove inhibitor and then vacuum distilled from CaH₂ and stored at − 20 °C prior to use. 2, 2-Bipyridine (bpy), copper bromide (CuBr), 2-bromoisobutyryl bromide, 2-aminoethyl methacrylate hydrochloride (AMA^.HCl), d-glucono-δ-lactone, bortezomib (BTZ), and Alizarin Red S (ARS) were all purchased from J&K and directly used. Methanol, toluene, triethylamine (TEA), 1-methyl-2-pyrrolidinone (NMP), and isopropyl alcohol (IPA) were purchased from Sinopharm Group Chemical Reagent Co., Ltd., and then distilled from CaH₂ under reduced pressure. Dichloromethane, chloroform, dimethyl sulfoxide (DMSO), and other organic solvents were purchased from Sinopharm Group Chemical Reagent Co., Ltd., and directly used without further purification. Bromide terminated poly(ethylene glycol) (PEG₁₁₃-Br) macroinitiator and 2-gluconamidoethyl methacrylate (GAMA) monomer were prepared from PEG₁₁₃-OH and 2-bromoisobutyryl bromide, and AMA^.HCl and d-glucono-δ-lactone, respectively, according to literature procedures [35 (link), 36 (link)].

Tertiary-butyl methacrylate (tBMA, TCI-EP), 2-hydroxyethyl methacrylate (HEMA, 99%, Aldrich), and poly (ethylene glycol) methyl ether methacrylate (PEGMA, M_n = 475 Da, 99%, Aldrich) were purified by passing through a neutral alumina column to remove the inhibitor. Pentaerythritol was dried under reduced pressure before use. Triethylamine (TEA), tetrahydrofuran (THF), dichloromethane (DCM), and toluene, all from J&K Scientific Ltd., were distilled from calcium hydride (CaH₂) prior to use. Cystamine dihydrochloride (98%, Aldrich), 2-bromoisobutyryl bromide (98%, J&K Scientific Ltd.), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA, 99%, J&K Scientific Ltd.), methacryloyl chloride (95%, J&K Scientific Ltd.), Pyrene (99%, J&K Scientific Ltd.), doxorubicin hydrochloride (DOX^.HCl) (Wuhan Yuancheng Gongchuang Technology Co., Ltd.), trifluoroacetic acid (TFA), cupric bromide (CuBr₂), stannous octoate (Sn(Oct)₂), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), n-hexane, and other reagents were used directly.