Development of high-efficiency superparamagnetic drug delivery system with MPI imaging capability oleh Shi Bai, Xiao-dan Zhang, Yu-qi Zou, Yu-xi Lin, Zhi-yao Liu, Ke-wen Li, Ping Huang, Takashi Yoshida, Yi-li Liu, Ming-shan Li, Wei Zhang, Xiao-ju Wang, Min Zhang, Cheng Du