6681
Catechol - initiated polyethers : multifunctional hydrophilic ligands for PEGylation and functionalization of metal oxide nanoparticles .
 Chemical: Catechol; Chemical: polyethers; Chemical: metal oxide
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: Catechol; Chemical: polyethers; Chemical: metal oxide