Role of Bone Marrow Mononuclear Cell Seeding for Nanofiber Vascular Grafts

Tissue Eng Part A. 2018 Jan;24(1-2):135-144. doi: 10.1089/ten.TEA.2017.0044. Epub 2017 Jun 13.


Objective: Electrospinning is a promising technology that provides biodegradable nanofiber scaffolds for cardiovascular tissue engineering. However, success with these materials has been limited, and the optimal combination of scaffold parameters for a tissue-engineered vascular graft (TEVG) remains elusive. The purpose of the present study is to evaluate the effect of bone marrow mononuclear cell (BM-MNC) seeding in electrospun scaffolds to support the rational design of optimized TEVGs.

Methods: Nanofiber scaffolds were fabricated from co-electrospinning a solution of polyglycolic acid and a solution of poly(ι-lactide-co-ɛ-caprolactone) and characterized with scanning electron microscopy. Platelet activation and cell seeding efficiency were assessed by ATP secretion and DNA assays, respectively. Cell-free and BM-MNC seeded scaffolds were implanted in C57BL/6 mice (n = 15/group) as infrarenal inferior vena cava (IVC) interposition conduits. Animals were followed with serial ultrasonography for 6 months, after which grafts were harvested for evaluation of patency and neotissue formation by histology and immunohistochemistry (n = 10/group) and PCR (n = 5/group) analyses.

Results: BM-MNC seeding of electrospun scaffolds prevented stenosis compared with unseeded scaffolds (seeded: 9/10 patent vs. unseeded: 1/10 patent, p = 0.0003). Seeded vascular grafts demonstrated concentric laminated smooth muscle cells, a confluent endothelial monolayer, and a collagen-rich extracellular matrix. Platelet-derived ATP, a marker of platelet activation, was significantly reduced after incubating thrombin-activated platelets in the presence of seeded scaffolds compared with unseeded scaffolds (p < 0.0001). In addition, reduced macrophage infiltration and a higher M2 macrophage percentage were observed in seeded grafts.

Conclusions: The beneficial effects of BM-MNC seeding apply to electrospun TEVG scaffolds by attenuating stenosis through the regulation of platelet activation and inflammatory macrophage function, leading to well-organized neotissue formation. BM-MNC seeding is a valuable technique that can be used in the rational design of optimal TEVG scaffolds.

Keywords: biodegradable scaffold; bone marrow mononuclear cell (BM-MNC) seeding; electrospinning; nanofiber; stenosis; tissue-engineered vascular graft (TEVG).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Vessel Prosthesis
  • Bone Marrow Cells / cytology*
  • Cells, Cultured
  • Female
  • Immunohistochemistry
  • Mice
  • Mice, Inbred C57BL
  • Tissue Engineering / methods*
  • Tissue Scaffolds / chemistry*