8459
Influence of surface groups on poly ( propylene imine ) dendrimers antiprion activity .
 Chemical: poly ( propylene imine )
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: poly ( propylene imine ) 
Answer:
 Chemical: poly ( propylene imine )