30181
The swelling ratios and moduli of the alginate - catechol hydrogels are readily tunable , which is difficult to achieve in ionic bond - based alginate hydrogels .
 Chemical: catechol
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: catechol 
Answer:
 Chemical: catechol