Abstract:

BACKGROUND: Angiogenesis attracts much attention in tissue engineering field. Previous research has proved that a two-dimensional culture of vascular endothelial growth factor (VEGF) promotes angiogenesis.
OBJECTIVE: To evaluate the effect of VEGF on three-dimensional angiogenesis.
METHODS: Endothelial progenitor cells were separated from the SD rat bone marrow. At about 70%-80% fusion, rat tail collagen gel was added to establish three-dimensional models. Samples in the experimental group were incubated in complete culture solution containing M199 culture media, fetal bovine serum, VEGF, and double antibody. The samples in the control group were incubated with VEGF-free culture media. In vitro culture and amplification of bone marrow-derived endothelial progenitor cells were determined at 1, 4, 7, and 20 days after incubation. Morphology and quantitative analysis were performed at 3, 6, 9, and 12 days after three-dimensional model establishment.
RESULTS AND CONCLUSION: Endothelial progenitor cells grew from three-dimensional matrix into collagen matrix in the experimental group. Budding and infiltration were observed in the collagen within 24 hours, and branching-like structure was then gradually formed. Cells in the control group grew slowly, with slowing budding, small tubiform structure, superficial infiltration into collagen, sparse network structure, and non-intact. Numbers of newborn vessels in the experimental group were significantly greater than control group (P < 0.01). A detection on gel block showed positive expressions of endothelin-1 and endothelial nitric oxide synthase-3 on the 3rd, 6th, 9th, and 12th days. The results demonstrated that VEGF mobilized and induced endothelial progenitor cells in order to promote angiogenesis. Rat tail collagen gel induced endothelial progenitor cells which behaved migration, proliferation, and pullulation of angiogenesis.