Rapid Engineered Autologous Blood Vessels

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David A. Vorp, PhD

University of Pittsburgh

William R. Wagner, PhD

University of Pittsburgh

Battlefield injury often involves traumatic damage of a major artery or vein, necessitating replacement. Larger blood vessels may be replaced or bypassed with synthetic vascular grafts. However, these synthetic options are not suitable for small diameter blood vessels, including those of the lower extremity (e.g., tibial artery), heart (coronary arteries), etc. Because of the rapid nature of the fabrication, if successful, the approach proposed with this research would be suitable for replacement of an injured soldier’s small-diameter blood vessel using his or her own bone marrow-derived HMSCs and an “off-the-shelf” available scaffold.


To demonstrate this possibility, the group has performed a “proof-of-concept” preliminary study whereby the stem cell seeded bioresorbable polymer scaffold proposed here was implanted as an interposition graft in the abdominal aorta of rats. The constructs had surgical capabilities (i.e. suture and handling) that were qualitatively considered to be appropriate and flow was restored with no leaks or oozing through the polymer after the anastomoses were completed. Angiograms at 2 and 3 weeks showed graft patency for both electrospun and TIPS polymers, respectively. Histology showed almost complete remodeling of the polymer in 2 weeks with the formation of an external capsule of aligned collagen fibers and formation of new capillary vessels. Scanning electron microscopy studies showed a very smooth integration between the polymer and the native tissue at the anastomosis level. Though an implantation study is not part of the current proposal, this preliminary work demonstrates that it will be possible to rapidly fabricate a TEVG in-vitro and implant it as a substitute for a small-diameter artery. This research l demonstrates feasibility with human, adult cells and characterize the engineered vessels in terms of important mechanical and physiological parameters.