7900
PKAA efficiently self - assembled with siRNA to form nanocomplexes with a diameter of ~ 200 nm and slightly positive charges , which are stable under physiological conditions , but rapidly release siRNA at acidic pH .
 Chemical: PKAA
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