Fig. 1
The characteristics of the scaffolds. a Gross observation of the PCL/HA composite scaffolds made by a 3D printer. b Micro-morphology and microstructure of the composite scaffolds. c Porosity of the scaffolds. d Compression strength of the scaffolds. e The proliferation of BMSCs after culturing for 1, 3, and 5 days on the scaffolds detected by the CCK-8 kit. f Presentation of the device used to generate sinusoidal electromagnetic fields (EMF). The device was constituted of the waveform generator, amplifier, oscilloscope, and Helmholtz coils. Cell-scaffolds were placed in the center of the Helmholtz coils, which were placed in a 5% CO2 and 37 °C incubator. g Live-dead staining images of BMSCs after culturing for 1 day and 3 days on the scaffolds. *p < 0.05 compared to the Ctrl group, **p < 0.01 compared to the Ctrl group