Targeted Antagonism of Vascular Endothelial Growth Factor Reduces Mortality of Mice with Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is associated with a mortality of 45%. Our previous research indicated that anti-vascular endothelial growth factor (VEGF) could maintain the normal structure and function of the respiratory barrier. However, systemic application of VEGF antagonists would lead to animal death. This study attempts to study the targeted drug delivery for ARDS. In this study, we used soluble fms-like tyrosine kinase-1 (sFlt)-targeted ultrasound microbubbles to antagonize the effect of VEGF on lung tissue. Ninety male BALB/c mice were randomly assigned to 6 groups: phosphate buffer saline (PBS) group (PBS+PBS); blank group (PBS+empty microbubbles); lipopolysaccharide (LPS) group (LPS+PBS); ARDS group (LPS+empty microbubbles); control group (PBS+sFlt microbubbles); and treatment group (LPS+sFlt microbubbles). After administration of LPS or PBS in the corresponding groups, the sFlt-targeted microbubbles or empty microbubbles were injected into the blood circulation. Then the lungs were irradiated with ultrasound, which ruptured the drug-loaded microbubbles and helped release drugs to the lung tissues targeted. The lung injury score, lung wet/dry ratio (W/D), liver and kidney functions, and the mortality of the mice in all groups were investigated at the predetermined time point. The difference in mortality between groups was examined by Fisher test. Other data were analyzed by one-way analysis of variance (ANOVA). A value of P<0.05 indicates that the difference was significant. The results showed that the PaO