Controlled release of vascular endothelial growth factor enhances intestinal adaptation in rats with extensive small intestinal resection

Background: Vascular endothelial growth factor (VEGF) has been shown to be an essential factor in the intestinal adaption after extensive bowel resection. The present study investigates the controlled release of VEGF as a way to improve intestinal adaptation. Materials and Methods: Biodegradable microspheres with or without VEGF were made using a double emulsion technique. Approximately 80% of the small intestine was removed, leaving the entire duodenum, 10 cm of jejunum, and 7 cm of ileum. The microspheres were distributed on the anastomosed small bowel. The animals were sacrificed after 14 days, and the adapted jejunum and ileum were analyzed for sucrase activity and histologic parameters. Results: The average villus lengths of the adapted jejunum and ileum were 680 and 350 μm in rats that received blank microspheres, compared to 810 and 720 μm in rats that received VEGF microspheres. The average sucrase activity of the adapted jejunum and ileum was 0.0202 and 0.0073 μmol/mg protein/min in rats that received blank microspheres, compared with 0.0236 and 0.0232 μmmol/mg protein/min in rats that received VEGF microspheres. Conclusion: The data suggest that the controlled delivery of VEGF from microspheres enhances the adaptation of the small intestine in rats. The controlled delivery of VEGF over time can potentially be used in patients following extensive intestinal resection.