1485
To further investigate the influence of the generation of hydroxyl radicals and adsorption of protein , poly ( ethylene - alt - maleic anhydride ) ( PEMA ) and chitosan were used to coat TiO ( 2 ) nanoparticles .
 Chemical: hydroxyl; Chemical: poly ( ethylene - alt - maleic anhydride ); Chemical: PEMA; Chemical: TiO ( 2 )
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: hydroxyl; Chemical: poly ( ethylene - alt - maleic anhydride ); Chemical: PEMA; Chemical: TiO ( 2 )