7473
Bio - based biodegradable and biocompatible hyperbranched polyurethane : a scaffold for tissue engineering .
 Chemical: polyurethane
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: polyurethane 
Answer:
 Chemical: polyurethane