点击放大环状聚乙二醇-聚乙二醇臂-叠氮(n=4)28-crown-9-PEG4-N3; Azido-terminated PEG arm on a cyclic poly(ethylene glycol) scaffold (arm n=4)
点击放大双臂-聚乙二醇-叠氮(n=4)2-Arm-PEG-N3 (n=4, per arm); 2-Arm azido-functionalized discrete poly(ethylene glycol) (PEG arm n=4)