The Making of Pegfilgrastim

The covalent attachment of polyethylene glycol (PEG) polymers to therapeutic drugs (pegylation) is one of the most widely used and well-established engineer- 

The reduction in renal clearance stems from the ability of the PEG moiety to become highly hydrated in aqueous solution (partially because of chain flexibility and extensive hydration) [11]. It has been shown that the molecular size increases more than proportionally with increasing numbers of 5-kDa PEG polymers attached to the native protein [29]. Studies of PEG polymers in solution have shown that each ethylene oxide unit is tightly associated with two to three water molecules. 

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