1479
To uncover the size influence of TiO ( 2 ) nanoparticles on their potential toxicity , the cytotoxicity of different - sized TiO ( 2 ) nanoparticles with and without photoactivation was tested .
 Chemical: TiO ( 2 ); 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: TiO ( 2 ); Chemical: TiO ( 2 )