7901
PKAA exhibited sufficient buffering capability and endosomolytic activity due mainly to the presence of secondary amine groups in its backbone and rapid degradation in acidic endosomes , leading to the enhanced release of siRNA to cytoplasm .
 Chemical: PKAA; Chemical: secondary amine
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: PKAA; Chemical: secondary amine