13879
In this work , we investigated the potential of novel bi - ligand ( transferrin - poly - l - arginine ) liposomal vector for delivery of desired gene to brain , in vivo .
 poly - l - arginine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 poly - l - arginine