1994
The present study examined the cytotoxic effects of spherical , citrate - coated AgNPs ( 10 , 50 and 100 nm ) in rat brain endothelial ( RBE4 ) cells and investigated whether the observed effects can be explained by the intrinsic toxicity of the particles or the silver ions released from the particles .
 Chemical: citrate; Chemical: silver
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: citrate; Chemical: silver