Background: Cardiovascular disease is responsible for a large number of deaths each year. Autologous vascular transplantation is still the best surgical intervention option, but the success rate is affected by many factors. Tissue engineering is a growing research area of great interest because it can produce bionic grafts to replace autologous tissue. Although many molding strategies have been tried, precellularization of small-diameter vascular grafts remains a research challenge. Here, a novel approach for fabricating bionic small-diameter vascular vessels with endothelial and smooth muscle cells is developed through combining nanofiber electrospinning and a specially-designed rotary bioprinter.
Results: Combining and utilizing the advantages of nanofiber electrospinning and rotary printing, a tissue-engineered vascular tissue more suitable for biological transplantation is fabricated. Electrospun poly(ε-caprolactone) (PCL) provides good elasticity, and the electrospinning modification is beneficial for adhesion and functionalization of endothelial cells. A flat monolayer on the surface of PCL is formed after 7 days cultivation. Modification of the traditional three-dimensional (3D) bioprinter to increase rotation of the central axis used dual motors rotating clockwise and anticlockwise at the same speed increase stability during the printing process. This allowed a uniform dense methacrylated gelatin (GelMA) structure containing smooth muscle cells to be bioprinted with the cells are arranged linearly along the horizontal axis of rotation. Perfused with umbilical vein endothelial cells, a monolayer endothelial structure is formed. The two type cells maintain viability and proliferation in the structure during the process of cultivation. In addition, the bionic structure
is superior to the natural blood vessel in anti-burst pressure and suture retention strength.
Conclusion: By combining nanofiber electrospinning and modified rotary bioprinter, we successfully formed a small-diameter bionic vascular vessel with smooth muscle cells and endothelial cells. This method takes advantages of two advanced technologies and provides a new strategy for the development of bionic blood vascular tissue.