MBP and bronchopulmonary dysplasia: ×400 magnification, Scale bar: 50 μm (C-D) Histogram showing quantitation of MBP expression (C) and GFAP expression (D) in RA, BPD, BPD + PBS, BPD + MSC-CM EXO 25 wks and BPD + MSC-CM EXO 30 wks groups.