点击放大双臂-聚乙二醇-NHS活性酯（n=4）2-Arm-PEG-CH2CH2COONHS Ester (n=4, per arm); 2-Arm N-hydroxysuccinimide ester-functionalized discrete poly(ethylene glycol) (PEG arm n=4)
点击放大三臂-聚乙二醇-NHS活性酯（n=4）3-Arm-PEG-CH2CH2COONHS Ester (n=4, per arm); 3-Arm N-hydroxysuccinimide ester-functionalized discrete poly(ethylene glycol) (PEG arm n=4)
