Blood vessels engineering cell seeding

Another example was done by Opitz et al. They utilized P4HB scaffolds to produce viable ovine blood vessels, and then implanted the blood vessels in the systemic circulation of sheep. Enzymatically derived vascular smooth muscle cells (vSMC) were seeded on the scaffolds both under pulsatile flow and static conditions. Mechanical properties of bioreactor-cultured blood vessels which were obtained from tissue engineering approached those of native aorta. 

Niklason and Langer studied the feasibility of using PLGA and PGA for tissue-engineered, small diameter blood vessels. They reported that PLGA films supported confluent monolayers of aortic smooth muscle and endothelial cells, and PGA mesh scaffolds developed a tissue-like appearance when seeded with aortic smooth muscle cells. They also claimed that PGA scaffolds formed into a tube did not maintain sufficient strength required for blood vessels, even with smooth muscle tissue formed on the polymer. In an effort to improve the results, they applied pulsatile stretch forces to the cell-polymer... 

Other attempts at tissue engineering blood vessels have been made by constructing the vessels ex vivo directly from the cellular components. This may be accomplished by culturing a sheet of human vascular smooth muscle cells in collagen and placing it within a lumenal support to produce tire media. A fibroblast sheet is then similarly cultured and placed about tire media to form the adventitia. Endothelial cells are later seeded into the lumen of the vessel, thus forming a mechanically soimd, three-dimensional vessel. 

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