7883
The effect of P ( GMA ) backbone length and structure of oligoamine on gene transfer efficiency was then determined .
 Chemical: P ( GMA ); Chemical: oligoamine
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: P ( GMA ); Chemical: oligoamine