5661
EGa1 - PEG functionalized nanoparticles showed a 40 - fold higher binding to EGFR - positive 14C squamous head and neck cancer cells in comparison to PEGylated nanoparticles .
 PEG, 14C
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 PEG, 14C