18965
A versatile chemical scheme is used to modify the reactive PEG microgels with tethered biomolecules to tune their bioactive properties for the bioreactor culture and manipulation of various ( stem ) cell types .
 Chemical: PEG
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: PEG 
Answer:
 Chemical: PEG