13719
Hyperbranched polylysine can be produced at low costs and in large quantities , is partially biodegradable , which may help to prevent cumulative cytotoxicity , and possesses transfection properties that can approach those of PEI .
 Chemical: polylysine; Chemical: PEI
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: polylysine; Chemical: PEI