The human heart beats approximately 35 million times every year, pumping blood into the circulation via four different heart valves. In more than four million people each year, heart valves fail for different reasons, including birth defects, age-related deteriorations and infections. At present, clinicians use either artificial prostheses or fixed animal and cadaver-sourced tissue to replace defective heart valves, however, they can cause unwanted side-effects, wear down and therefore need to be replaced with invasive and expensive surgical procedures. Especially in children, heart valve prostheses need to be replaced even more often as they cannot grow with the rest of the body.
Researchers at the Wyss Institute, the Harvard John A. Paulson School of Engineering and Applied Sciences and the University of Zurich’s Institute for Regenerative Medicine have developed a nanofiber fabrication technique that is able to rapidly manufacture heart valves with regenerative and growth potential. The technique uses a proprietary rotary jet spinning technology in which a rotating nozzle extrudes a solution containing so-called extracellular matrix (ECM) proteins — that are also part of the make-up of natural heart valves — into nanofibers that wrap themselves around heart valve-shaped mandrels. By providing a series of mandrels produced for different valve types and sizes, the process is customizable to different age groups and conditions, and much faster and cost-effective than the production of other regenerative prostheses.
This new type of heart valve can be implanted with minimally invasive surgical procedures applicable to all age groups. In first preclinical studies in sheep they proved to properly support the animals’ circulation right after implantation and to regenerate new heart-like tissue over time, opening the possibility for a highly flexible and long-term therapeutic solution for heart valve disease.