Cardiovascular Engineering and Technology

, Volume 1, Issue 2, pp 138–153 | Cite as

Design and Testing of a Pulsatile Conditioning System for Dynamic Endothelialization of Polyphenol-Stabilized Tissue Engineered Heart Valves

  • Leslie Neil Sierad
  • Agneta Simionescu
  • Christopher Albers
  • Joseph Chen
  • Jordan Maivelett
  • Mary Elizabeth Tedder
  • Jun Liao
  • Dan T. SimionescuEmail author


Heart valve tissue engineering requires biocompatible and hemocompatible scaffolds that undergo remodeling and repopulation, but that also withstand harsh mechanical forces immediately following implantation. We hypothesized that reversibly stabilized acellular porcine valves, seeded with endothelial cells and conditioned in pulsatile bioreactors would pave the way for next generations of tissue engineered heart valves (TEHVs). A novel valve conditioning system was first designed, manufactured and tested to adequately assess TEHVs. The bioreactor created proper closing and opening of valves and allowed for multiple mounting methods in sterile conditions. Porcine aortic heart valve roots were decellularized by chemical extractions and treated with penta-galloyl glucose (PGG) for stabilization. Properties of the novel scaffolds were evaluated by testing resistance to collagenase and elastase, biaxial mechanical analysis, and thermal denaturation profiles. Porcine aortic endothelial cells were seeded onto the leaflets and whole aortic roots were mounted within the dynamic pulsatile heart valve bioreactor system under physiologic pulmonary valve pressures and analyzed after 17 days for cell viability, morphology, and metabolic activity. Our tissue preparation methods effectively removed cells, including the potent α-Gal antigen, while leaving a well preserved extracellular matrix scaffold with adequate mechanical properties. PGG enhanced stabilization of extracellular matrix components but also showed the ability to be reversible. Engineered valve scaffolds encouraged attachment and survival of endothelial cells for extended periods and showed signs of widespread cell coverage after conditioning. Our novel approach shows promise toward development of sturdy and durable TEHVs capable of remodeling and cellular repopulation.


Tissue engineered heart valves Stabilization Endothelial cells Biaxial mechanical testing Scanning electron microscopy 



This work was funded in part by National Institutes of Health grants P20 RR-016461 and HL084194 (DS) and HL097321 (JL). J. M. was funded in part by Howard Hughes Medical Institute and the South Carolina Life Undergraduate Research Program. The authors wish to thank Snow Creek Meat Processing (Seneca, SC) for generous access to tissues, Clemson University Machining and Technical Services (Clemson, SC) for bioreactor manufacturing, Mrs. Linda Jenkins, HT, ASCP for help with histology and Mr. Jeremy Mercuri for help with tissue collection.

Supplementary material

Video showing a glutaraldehyde-fixed stented porcine bioprosthetic aortic heart valve functioning in the heart valve bioreactor. Top view (from aorta) recorded through the atrial chamber. To view continuous action please use “loop” feature of the media player (MPG 6900 kb)

Video showing a PGG-treated decellularized and endothelial cell-seeded heart valve functioning in the heart valve bioreactor in DMEM cell culture medium (red fluid). Top view (from aorta) recorded through the atrial chamber. This is the same as valve (a) in Fig. 6; the right coronary cusp is shown on the lower left corner of the valve sinus. To view continuous action please use “loop” feature of the media player (AVI 894 kb)


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Copyright information

© Biomedical Engineering Society 2010

Authors and Affiliations

  • Leslie Neil Sierad
    • 1
  • Agneta Simionescu
    • 1
  • Christopher Albers
    • 1
  • Joseph Chen
    • 2
  • Jordan Maivelett
    • 1
  • Mary Elizabeth Tedder
    • 1
  • Jun Liao
    • 2
  • Dan T. Simionescu
    • 1
    Email author
  1. 1.Biocompatibility and Tissue Regeneration Laboratory, Department of BioengineeringClemson UniversityClemsonUSA
  2. 2.Department of Agricultural and Biological EngineeringMississippi State UniversityMississippi StateUSA

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