Fig. 2. (A) The isolated primary ADSCs began to form colonies after two days of culture and showed uniform stellate cell morphology when passed to the third passage. Bright field, ×20. (B) The effect of PEI-SPION on cell viability was determined by CCK-8 method. When the concentration of PEI-SPION was 10 ug/mL, it would not have an apparent toxic effect on ADSC. ADSC, adipose-derived stem cell; PEI-SPION, superparamagnetic iron oxide nanoparticles modified with polyethyleneimine. ^*p<0.05.