Review Article

Poly(ethylene glycol)-Prodrug Conjugates: Concept, Design, and Applications

Figure 5

(a) NHS esters compounds react with nucleophiles to release the NHS leaving group and form an acetylated product. (b) PEG can be succinylated to form –COOH group, which can further form amide or ester bond with biomolecules.
103973.fig.005a
(a)
103973.fig.005b
(b)