24144
Polypeptides are successfully incorporated into poly ( l - lactide ) ( PLLA ) chains in a ring - opening polymerization ( ROP ) of l - lactide by using them as initiators .
 poly ( l - lactide ), PLLA, l - lactide
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 poly ( l - lactide ), PLLA, l - lactide