小肠黏膜下层促血管内皮细胞体外增殖及成血管化作用

Objective: To investigate the role of small intestinal submucosa (SIS) in promoting the proliferation and vascularization of umbilical vein endothelial cells (UVECs) in vitro. Methods: UVECs were isolated by collagenase digestion method, and then cultured and identified by morphology and immunofluorescence. SIS was prepared by tissue engineering technique; then its components were analyzed by immunohistochemistry and enzyme linked immunosorbent assay (ELISA) methods. The co-culture system of UVECs and SIS was established; UVECs cultured alone were set as the control group. The proliferation and vascularization of UVECs were compared between the two groups. Results: Immunohistochemical test showed that the prepared SIS was mainly composed of the extracellular matrix components type Ⅰ and Ⅲ collagens. The concentrations of vascular endothelial growth factor (VEGF) and basic fibroblast growth factors (b-FGF) in SIS incubation solution detected by ELISA were (48.83±5.67)ng/mL and (72.36±8.71)ng/mL, respectively. When cultured in vitro, there were angiogenesis and high cell density in UVECs and SIS co-cultured group than in UVECs cultured alone group. Growth curve of UVECs obtained by UVECs count showed that the proliferation ability of UVECs in UVECs and SIS co-cultured group was higher than that in the cultured alone group. Growth curve of UVECs showed at days 4 and 5 of logarithmic phase, UVECs count in UVECs and SIS co-cultured group was (7.91±0.42)×10 ⁴ and (9.15±0.48)×10 ⁴ , while that in the UVECs cultured alone group was (4.26±0.27)×10 ⁴ and (6.71±0.31)×10 ⁴ (P<0.01). Population doubling time of UVECs in UVECs and SIS co-cultured group was shorter than that in the UVECs cultured alone group (P<0.01). Conclusion: SIS can promote the proliferation and vascularization of UVECs in vitro by its extracellular matrix components type I and III collagens, and its components VEGF and b-FGF.