Fig. 4

Animal experimental design and representative x-rays of distraction regenerate at various time points. a After a 5-day latency period, distraction was initiated over 10 days at 1 mm/day in two equal increments. Local injection of PBS, serum-free α-MEM, and secretome started from the beginning of the consolidation phase, and every 3 days thereafter until termination. b Little callus was seen in the gap immediately after distraction in three groups, while more continuous callus appeared in the secretome group as time went on, especially at the end of the consolidation phase, whereas an obvious gap was still seen in the other two groups. d day, hFMSC human fetal mesenchymal stem cell, PBS phosphate-buffered saline