Fibrin and Collagen Differentially but Synergistically Regulate Sprout Angiogenesis of Human Dermal Microvascular Endothelial Cells in 3-Dimensional Matrix
Figure 5
Fibrin gels (a, c, e, g) and collagen gels (b, d, f, h) differentially regulated HDMEC response to VEGF (30 ng/mL) and bFGF (25 ng/mL). Without the addition of angiogenesis factors, little or no sprout formation, invasion, or migration of HDMEC occurred either in fibrin gel (a) or in collagen gel (b). In the presence of VEGF (30 ng/mL) and bFGF (25 ng/mL), HDMEC formed capillary sprouts which invaded and migrated into fibrin gel within 48 hr (c). In contrast, in collagen gel in the presence of VEGF (30 ng/mL) and bFGF (25 ng/mL), HDMEC invaded and migrated into the gel individually without forming capillary sprouts (d). After 5 days, the capillary sprouts in fibrin elongated and branched (e). IF staining revealed that the capillary sprouts in fibrin were formed by multiple, lineal aligned cells (g). After 5 days, HDMEC randomly migrated into collagen gel without forming capillary sprouts (f). IF staining revealed that the nuclei were randomly distributed in collagen gel (h) (100x magnification).
