Synthesis and detection of magnetic poly lactic acid-glycolic acid copolymer-bone morphogenetic protein 2 microspheres applied in tissue engineered bone  
Tian Zhi-chao1, Yang Yang2, Xiao Jun1, Qiu Jin-jun3, Zhu Yuan-li4, Li Liang-yu1
Chinese Journal of Tissue Engineering Research . 2012, (16): 2927 -2930 .  DOI: 10.3969/j.issn.1673-8225.2012.16.018