点击放大环状聚乙二醇-聚乙二醇臂-巯基（n=45）274-crown-91-PEG45-SH; Thiol-terminated PEG arm on a cyclic poly(ethylene glycol) scaffold (arm n=45)
点击放大Y型-双臂-甲氧基-聚乙二醇-NHS活性酯（n=45）Y-(mPEG45)2-NHS; Y-shaped bis(methoxy-poly(ethylene glycol)) with a single N-hydroxysuccinimide ester conjugation handle (PEG arm n=45)
点击放大Y型-双臂-甲氧基-聚乙二醇-马来酰亚胺（n=45）Y-(mPEG45)2-Mal; Y-shaped bis(methoxy-poly(ethylene glycol)) with a single Mal conjugation handle (PEG arm n=45)
