Objective: To evaluate the effect of seeding vascular smooth muscle cells and endothelial cells sequentially on biodegradable scaffold in vitro.
Methods: Venous endothelial cells and smooth muscle cells of artery were isolated from the umbilical cord of newborn and cultured in vitro. The cultured arterial smooth muscle cells and cultured endothelial cells were seeded on the polyglycolic acid and polylactide (PLGA) nonwoven mesh as tissue scaffolds respectively (group A and group B). And cultured endothelial cells were seeded on the scaffold already seeded with smooth muscle cells sequentially to construct vascular patch (group C). One month after cultivation the patches of the 3 groups underwent HE staining and microscopic examination and scanning electron microscopy. Immunohistochemistry was used to examine the existence of actin and factor VIII-related antigen, secreted by endothelial cells, in the cells. The levels of endothelin and 6-Keto-PGF1alpha in the culture solution were examined by means of radioimmunology so as to measure the endothelial function. Pure culture solution was used as blank control (group D).
Results: Microscopy showed that cells were fused into patch in the group C. HE staining showed that the smooth muscle cells were embedded into the PLGA scaffold and grew in multiple layers covered by a layer of endothelial cells on the surface. The types of cells could be identified by immunohistochemical procedure. The levels of endothelin and 6-Keto-PGF1alpha in the culture solution were 229 pg/ml +/- 34 pg/ml and 402 pg/ml +/- 108 pg/ml respectively in the group C, and 200 pg/ml +/- 31 pg/ml and 336 pg/ml +/- 121 pg/ml in the group B, both significantly higher than those in the groups A and D (blank control group, all P < 0.05 or P < 0.05).
Conclusion: Tissue engineering blood vessel with normal morphological and functional characters to a certain degree can be constructed through seeding cultured vascular smooth muscle cells and endothelial cells sequentially on PLGA scaffold.