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Researchers at Qatar University are developing biologically engineered heart valves to take the place of traditional surgery and transplants
Qatar University is collaborating with Imperial College London, US biotech company Biostage and the American University of Beirut to develop heart valves that can grow with the body and integrate with the patient’s native tissue.
The team generated the heart valves using a combination of nanotechnology, 3D printing and tissue engineering, the latter of which involves recently developed techniques to grow living cells into functional tissues or organs.
Tissue engineering has already been used to successfully develop human skin and bladders. Anwarul Hasan, an engineer at Qatar University, says: “Biologically engineered organs and tissues are in high demand, especially due to an enormous shortage of organ donors.”
Heart valve disease is one of the most common reasons for cardiac failure. According to iData Research, more than 182,000 people a year require heart valve replacements in the US alone.
The two main options available for heart valve replacement are currently mechanical and bio-prosthetic valves.
Mechanical valves, which are often made from metal, require patients to take blood thinning agents for the rest of their lives, while bio-prosthetics, made from animal tissue, have a limited life span and must be replaced after 10 to 20 years of use.
Both types of valve are unable to grow with time, meaning that young patients may have to undergo several valve replacement operations during their lifetime.
According to Dr Hasan: “Bioengineered tissue valves will last longer, be adopted by the body without rejection, and grow with the patient’s growth.”
Using a special nanofibre-based biomaterial that is strong, flexible and biodegradable, researchers first made a 3D scaffold shaped like a heart valve. Then they injected the scaffold with living cardiac stem cells and cultured it in a tissue incubator. The cells grew and multiplied over a period of 15 days, gradually and partially replacing the scaffold, which slowly degraded. This process is expected to continue inside the body after implantation, until the valve is fully integrated with the patient’s native tissue.
A novel method was developed to simulate a cardiac system, which allows to test how the engineered valves affect blood flow. The results showed that the tissue engineered heart valves mimicked the functions of natural heart valves, opening and closing effectively at speeds and pressures similar to mechanical and bio-prosthetic heart valves. The tissue engineered heart valves have only been tested in the lab so far.
Next, researchers plan to test the valves in living organisms under various conditions to assess if they can be safely investigated for humans. Longer-term experiments are needed to fully understand the degradation and cell growth process inside the body.
Find out more about heart valve research at Qatar University.
