video: Video showing how the tissue-engineered heart valve opens and closes in culture. This material relates to a paper that appeared in the 9 May, issue of Science Translational Medicine, published by AAAS. The paper, by M.Y. Emmert at University of Zurich in Zurich, Switzerland and colleagues was titled, "Computational modeling guides tissue-engineered heart valve design for long-term in vivo performance in a translational sheep model" view more
Credit: M.Y. Emmert <i>et al., Science Translational Medicine </i>(2018)
Scientists have harnessed the power of computational modeling to design a bioengineered heart valve that emulates the properties of native heart valves. The tissue-engineered heart valve (TEHV) was safe and performed well one year following transplantation into sheep, indicating it may one day offer a therapeutic tool for patients with heart valve conditions. Patients usually receive prosthetic heart valves for valvular heart disease (which remains a major global health burden), yet current prostheses suffer from limited longevity and fail to grow properly in young patients. Researchers have long explored using bioengineering approaches to create living heart valve replacements that can regenerate and remodel themselves to better accommodate the native circulatory system. However, none of the TEHVs under evaluation to date contain the unique properties of native heart valves needed to continuously adapt to changes in blood flow over time. To overcome this hurdle, Maximilian Emmert and colleagues used computational modeling to predict how TEHVs would remodel over time after transplantation - a strategy that allowed them to design a longer-lasting TEHV with improved valve mechanics and tissue structure. Importantly, their model estimated in which directions the valves would stretch to compensate for later remodeling. The authors manufactured the TEHVs from blood vessel cells seeded on polymer mesh structures growing in culture over four weeks, before removing the cellular components and implanting the valves into 11 sheep. MRI imaging revealed that nine of the 11 TEHVs still functioned at the end of the year-long study and remodeled themselves in a similar fashion to native heart valves. In a related Focus, Jonathan Butcher says the study solves a complex outstanding problem and represents, "a critical advance for clinical translation" of TEHV technology.
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Journal
Science Translational Medicine