Heart valve replacement surgery, a life-saving procedure, has been available for over six decades. However, it comes with significant medical limitations, whether the valves used are mechanical or biological. Patients with mechanical heart valves need lifelong medication to prevent blood clotting. Biological valves, in contrast, have a lifespan of only 10 to 15 years. The situation is even more complex for children with congenital heart defects, as their growing bodies necessitate multiple valve replacements before they reach adulthood. Now, recent research suggests that the natural repair mechanisms in humans can be leveraged to build a living heart valve that grows inside the body along with the patient.

The new approach developed by researchers at Imperial College London (London, UK) involves a procedure that begins with a nanofibrous polymeric valve created from a biodegradable polymer scaffold, unlike the durable plastic that is typically used. Once implanted, this scaffold recruits cells and guides their development, turning the body into a bioreactor for new tissue growth. Over time, the scaffold is naturally replaced by the body's own tissues. At the heart of this innovation is the scaffold material, designed to attract, house, and direct the patient's cells, thereby encouraging tissue growth while preserving valve functionality.

The research team conducted laboratory validation studies and reported the initial results from animal tests. The valves, transplanted into sheep, were observed for up to six months. They functioned effectively throughout this period and demonstrated promising cellular regeneration. Notably, the study highlighted the scaffold's ability to attract blood cells that transform into functional tissues through a process known as endothelial-to-mesenchymal transformation (EndMT). Additionally, nerve and fatty tissue growth within the scaffold was observed, mirroring what one would expect in a normal valve. Concurrently, the polymer scaffold underwent degradation, paving the way for new tissue growth. This degradation was monitored using gel permeability chromatography (GPC) at the Agilent Measurement Suite (AMS) in Imperial’s Molecular Sciences Research Hub in White City, which is equipped with sophisticated analytical tools.

Further research is needed to fully understand the mechanisms behind the polymer's degradation and its correlation with tissue regeneration. The next phase involves extending animal studies to monitor tissue regeneration over longer periods. This data will be vital for obtaining regulatory approval for the first human clinical trials, expected within the next five years. Additionally, refining the manufacturing processes of the valves is necessary. As the project progresses, the team plans to seek commercial partners for later-stage clinical trials. Although currently focused on heart valve replacement, this technology has potential applications in other areas, such as treating vascular conditions, repairing blood vessels damaged by dialysis, and creating cardiac patches for heart repair.

“The aim of the concept we’ve developed is to produce a living valve in the body, which would be able to grow with the patient,” said Dr. Yuan-Tsan Tseng, a biomaterials scientist. “Once you have the scaffold, it becomes a platform technology that you can use to engineer other tissues.” 

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