点击放大四臂-聚乙二醇-氨基（n=16）4-Arm-PEG16-NH2; 4-Arm primary amine-functionalized discrete poly(ethylene glycol) (PEG arm n=16)
点击放大四臂-聚乙二醇-NHS活性酯（n=16）4-Arm-PEG16-CH2CH2COONHS Ester; 4-Arm N-hydroxysuccinimide ester-functionalized discrete poly(ethylene glycol) (PEG 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)
