Table 1 Body and lung weights and lung-to-body-weight ratios in 14-day-old rats exposed to RA or hyperoxia and treated with NS or surfactant on postnatal day 4 and NS or MSCs on postnatal day 5

RA + NS + NS

13

23.62 ± 2.57

0.41 ± 0.03

1.74 ± 0.21

RA + surfactant + NS

11

25.75 ± 4.94

0.45 ± 0.06

1.79 ± 0.20

O₂ + NS + NS

5

23.22 ± 7.01

0.39 ± 0.17

1.64 ± 0.50

O₂ + surfactant + NS

8

22.83 ± 4.62

0.42 ± 0.09

1.86 ± 0.26

O₂ + surfactant + hUC-MSCs (3 × 10⁴)

8

24.39 ± 7.07

0.46 ± 0.12

1.94 ± 0.47

O₂ + surfactant + hUC-MSCs (3 × 10⁵)

5

23.41 ± 1.67

0.40 ± 0.04

1.70 ± 0.13