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In this study , we modified the amino groups of the polymer with succinyl anhydride ( PU - Su ) or acetyl anhydride ( PU - Ac ) to determine the effects of these ionic groups on the UCST behavior and to control interactions between the PU derivatives and biocomponents such as proteins and cells .
 Chemical: amino; Chemical: succinyl anhydride; Chemical: PU - Su; Chemical: acetyl anhydride; Chemical: PU - Ac
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: amino; Chemical: succinyl anhydride; Chemical: PU - Su; Chemical: acetyl anhydride; Chemical: PU - Ac