7899
PKAA was designed to have acid - cleavable ketal linkages in the backbone of cationic biodegradable poly ( amidoamine ) .
 Chemical: PKAA; Chemical: poly ( amidoamine )
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: poly ( amidoamine )