The tissue-engineered vascular graft using bone marrow without culture

Objective: To overcome the shortcomings of current vascular grafts, tissue-engineering methods have been applied to cardiovascular regions. We previously reported the creation of a tissue-engineered vascular graft by using vascular mixed cells. However, the cost and manpower for harvesting and culturing the cells was too burdensome. To overcome these drawbacks, we have developed a new method for creating a tissue-engineered vascular graft by using bone marrow cells, which can be obtained easily and used immediately, without cell culture. Methods: Biodegradable polymers seeded with different types of cells (group V, cultured venous cells; group B, bone marrow cells without culture; and group C, non-cell-seeded graft [as control]) were implanted into the inferior venae cavae of dogs. The grafts were explanted at 4 weeks and assessed histologically and biochemically. Results: In the histologic examination, a regular layer of Masson-staining collagen fiber and a layer of factor VIII-stained endothelial and anti-a-smooth muscle cell antigen-immunoreactive cells stained in groups V and B like native vascular tissue, whereas no such stained regular lining was detected in group C. A 4-hydroxyproline assay in group C showed significantly lower levels than in groups V and B or native tissue (P < .05). The DNA content of the tissue-engineered vascular graft tended to be higher in group C than in groups V and B or in native tissue. Conclusions: In the creation of tissue-engineered vascular grafts, the method of using bone marrow cells seems to be useful and superior to that of using vascular cells because bone marrow cells can be used directly, without culture.