| Summary: | Nondegradable synthetic polymer vascular grafts currently used in cardiovascular surgery have no growth
potential. Tissue-engineered vascular grafts (TEVGs) may solve this problem. In this study, we developed a TEVG
using autologous bone marrow–derived cells (BMCs) and decellularized tissue matrices, and tested whether
the TEVGs exhibit growth potential and vascular remodeling in vivo. Vascular smooth muscle–like cells and
endothelial-like cells were differentiated from bone marrow mononuclear cells in vitro. TEVGs were fabricated by
seeding these cells onto decellularized porcine abdominal aortas and implanted into the abdominal aortas of
4-month-old, bone marrow donor pigs (n¼4). Eighteen weeks after implantation, the dimensions of TEVGs were
measured and compared with those of native abdominal aortas. Expression of molecules associated with vascular
remodeling was examined with reverse transcription–polymerase chain reaction assay and immunohistochemistry.
Eighteen weeks after implantation, all TEVGs were patent with no sign of thrombus formation, dilatation, or
stenosis. Histological and immunohistochemical analyses of the retrieved TEVGs revealed regeneration of endothelium
and smooth muscle and the presence of collagen and elastin. The outer diameter of three of the four
TEVGs increased in proportion to increases in body weight and outer native aorta diameter. Considerable extents
of expression of molecules associated with extracellular matrix (ECM) degradation (i.e., matrix metalloproteinase
and tissue inhibitor of matrix metalloproteinase) and ECM precursors (i.e., procollagen I, procollagen III, and
tropoelastin) occurred in the TEVGs, indicating vascular remodeling associated with degradation of exogenous
ECMs (implanted decellularized matrices) and synthesis of autologous ECMs. This study demonstrates that the
TEVGs with autologous BMCs and decellularized tissue matrices exhibit growth potential and vascular remodeling
in vivo of tissue-engineered artery.
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