点击放大环状聚乙二醇-聚乙二醇臂-羟基(n=24)148-crown-49-PEG24-OH; Hydroxyl-terminated PEG arm on a cyclic poly(ethylene glycol) scaffold (arm n=24)
点击放大三臂-聚乙二醇-羟基(n=24)3-Arm-PEG24-OH; 3-Arm hydroxyl-functionalized discrete poly(ethylene glycol) (PEG arm n=24)