Vascular endothelial growth factor promotes brain tissue regeneration with a novel biomaterial polydimethylsiloxane-tetraethoxysilane

In the brain after infarction or trauma, the tissue eventually becomes pannecrotic and forms a cavity. In such situations, a scaffold is necessary for the implanted or migrated cells to produce new tissue. In this present study, therefore, we attempted to restore brain tissue using a novel biomaterial, polydimethylsiloxane-tetraethoxysilane (PDMS-TEOS) hybrid with or without vascular endothelial growth factor (VEGF), which is crucial for new vessel formation. When PDMS-TEOS scaffold was implanted into the artificial brain defect, it remained at the implanted site and kept the integrity of the brain shape. At 30 days after the implantation, the marginal territory of PDMS-TEOS scaffold became occupied by newly formed tissue. Immunohistochemical analysis revealed that the new tissue was constituted by astrocytes and endothelial cells. Addition of VEGF increased the newly produced tissue volume, and the immunohistochemical analysis showed that the numbers of astrocytes and endothelial cells were increased. Double staining with proliferation maker Ki67 demonstrated that VEGF significantly increased newly formed astrocytes and endothelial cells, indicating that addition of VEGF accelerated tissue restoration and angiogenesis. These findings show that implantation of PDMS-TEOS scaffold with VEGF might be effective for treating old brain infarction or trauma.