Fig. 2From: Remote-controllable bone-targeted delivery of estradiol for the treatment of ovariectomy-induced osteoporosis in ratsGeneral characteristics of NPs. a Hydrodynamic diameter (blue) and zeta potential (red) of NPs by DLS. b Hydrodynamic diameter distribution of PEG-PLGA-AL@Fe3O4/E2 NPs at different measurement time: 24Â h (red line), 48Â h (blue line), 72Â h (green line). c SEM images and d AFM images of PEG-PLGA@Fe3O4/E2 NPs and PEG-PLGA-AL@Fe3O4/E2 NPsBack to article page