8971
Sequential release characterized by rapid release of angiogenic bFGF and more sustained release of BMP - 2 was obtained by loading bFGF onto cationic nanospheres of low crosslinking density and BMP - 2 onto anionic nanospheres of high crosslinking density .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None