点击放大环状聚乙二醇-聚乙二醇臂-巯基（n=16）100-crown-33-PEG16-SH; Thiol-terminated PEG arm on a cyclic poly(ethylene glycol) scaffold (arm n=16)
点击放大四臂-聚乙二醇-巯基（n=16）4-Arm-PEG16-SH; 4-Arm thiol-functionalized discrete poly(ethylene glycol) (PEG arm n=16)
