20836
We report the design and synthesis of small - sized zwitterion - coated gadolinium - embedded iron oxide ( GdIO ) nanoparticles , which exhibit a strong T1 contrast effect for tumor imaging through enhanced permeation and retention effect and the ability to clear out of the body in living subjects .
 Chemical: gadolinium; Chemical: iron oxide; Chemical: GdIO
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: gadolinium, iron oxide, GdIO 
Answer:
 Chemical: gadolinium; Chemical: iron oxide; Chemical: GdIO