21723
Rapid self - healable poly ( ethylene glycol ) hydrogels formed by selective metal - phosphate interactions .
 Chemical: poly ( ethylene glycol ); Chemical: phosphate
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: poly ( ethylene glycol ); Chemical: phosphate