Harvard’s synthetic heart valve is designed to grow in step with the human body

The FibraValve may eventually negate the need for multiple surgeries in pediatric valve replacements.

Wyss Institute at Harvard University / Matter

Researchers have developed a promising synthetic heart valve that may eventually be used for growing children. Harvard’s Wass Institute and John A. Paulson School of Engineering and Applied Sciences (SEAS) created what they call FibraValve. This implant can be manufactured in minutes using a spun-fiber method that lets them shape the valve’s delicate flaps on a microscopic level — ready to be colonized by the patient’s living cells, developing with them as they mature.

FibraValve is a follow-up to JetValve, the team’s 2017 artificial heart valve that employed many of the same principles. The updated version uses “focused rotary jet spinning,” which adds streams of focused air to more quickly and accurately collect synthetic fibers on a spinning mandrel — making it easier to fine-tune the valve’s shape. As a result, the polymer’s micro- and nano-fibers can more precisely replicate the tissue structure of an organic heart valve. The manufacturing process takes less than 10 minutes; alternative methods can require hours.

Diagram showing various parts of the FibraValve process: a device on the left (including motor, air inflow and solution tubes) forming a stream of fibers gathered on a collection mandrel with motor (right).
Wyss Institute at Harvard University

The technique also uses “a new, custom polymer material” called PLCL (a combination of polycaprolactone and polylactic acid) that can last inside a patient’s body for about six months — enough time (in theory) for the patient’s cells to infiltrate the structure and take over. Although it’s only been successfully tested in sheep so far, the long-term vision is for the resulting organic tissue to develop with human children as they mature, potentially voiding the need for risky replacement surgeries as their bodies grow. “Our goal is for the patient’s native cells to use the device as a blueprint to regenerate their own living valve tissue,” said corresponding author Kevin “Kit” Parker in Harvard's press release.

In the researchers’ test on a living sheep, the FibraValve “started to function immediately, its leaflets opening and closing to let blood flow through with every heartbeat.” Additionally, they observed red and white blood cells and fibrin protein collecting on the valve’s scaffolding within the first hour. The scientists say the synthetic valve showed no signs of damage or other problems. “This approach to heart valve replacement might open the door towards customized medical implants that regenerate and grow with the patient, making children’s lives better,” said co-author Michael Peters in the same press release.

The research is still preliminary, and the team plans to conduct longer-term animal testing over weeks and months for further evaluation. However, they believe their breakthrough could eventually find other uses, including creating different valves, cardiac patches and blood vessels. You can read the entire paper on Matter.