Diethyl carbonate

Glycerol (ACS, ≥99.5%) were purchased from Macklin Biochemical Co., Ltd (Shanghai, China). Iron nitrate nonahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate, cupric nitrate trihydrate, zinc nitrate hexahydrate and 50% manganous nitrate solution, dimethyl carbonate (DMC), diethyl carbonate (DEC), Glycerol carbonate (GC), n-butanol, benzyl alcohol were all analytical reagent grade and obtained from Sinopharm Chemical Reagent Co., Ltd. Others were also of analytical grade and used as-received without further purification.

PEG with Mn of 6 K and of 10 K g/mol was obtained from Sigma-Aldrich (USA), and vacuum dried at 60 °C overnight to remove residual water before use. Stannous octoate, trimethylamine (TEA), DOX, acryloyl chloride, dichloromethane, dimethyl phenylphosphonite, 2,4,6-trimethylbenzoly chloride, lithium bromide, and 2-butanone were purchased from Aladdin (China), and used as received. Diethyl carbonate, 1,3-propanediol, dimethylbenzene, dibutyltin dilaurate, zinc powder and sodium metal were supplied by Sinopharm Chemical Reagent Co., Ltd (Shanghai, China). SK-BR-3 and L929 cells were purchased from ATCC (USA). Fetal bovine serum (FBS), pH 7.4 phosphate-buffered saline (PBS), MoCoy 5A and DMEM with penicillin and streptomycin were obtained from Gibco (USA). Transwell with PC membrane was purchased from Corning (USA).