18671
In contrast , protein release from 1 , 4 - butanediamine cross - linked nanogels ( reduction - insensitive control ) remained low under otherwise the same conditions .
 Chemical: 1 , 4 - butanediamine
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: 1 , 4 - butanediamine