A dynamically cultured collagen/cells-incorporated elastic scaffold for small-diameter vascular grafts

There is an essential demand for tissue-engineered autologous small-diameter vascular grafts, which offer temporary supports and guides for vascular tissue organization, repair and remodeling. This study reports on the effect of collagen/smooth muscle cells (SMCs) mixtures under dynamic cultures and SMC-endothelial cell (ECs) co-culture on cell proliferation, uniform cell distribution, extracellular matrix deposition, and endothelial cells monolayer formation in tissue-engineered tubular arterial constructs of 4 mm inner diameter. Rabbit aortic SMCs were infiltrated with collagen solution in poly(L-lactide-co-ϵ-caprolactone) (PLCL) scaffolds under vacuum to form collagenous gel and subjected to dynamic strain by culturing them in a dynamic perfusion bioreactor. The construct lumen was subsequently seeded with ECs and experiments were completed to create ECs-SMCs co-culture constructs. The collagen/SMCs incorporated elastic scaffold cultured under dynamic culture conditions promoted matrix deposition, leading to the development of tissue-engineered vascular constructs, and induced SMC to have more uniform cell distribution. Scanning electron microscopic examination and von Willebrand Factor staining demonstrated the presence of ECs spread over the lumen. Quantitative analysis of elastin contents demonstrated that the engineered vessels acquired similar elastin contents as native arteries. The collagen/SMCs/ECs incorporated PLCL scaffolds under dynamic culture conditions can be used as a scaffold for tissue engineering to facilitate small-diameter vascular-tissue formation.