26000
Hydrogel microspheres , e . g . for the use as protein carriers , can be prepared without the use of organic solvents via an emulsified aqueous two - phase system ( ATPS ) that is based on two immiscible polymer solutions .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None