Future prospects in the tissue engineering of heart valves: a focus on the role of stem cells

Introduction Heart valve disease is a growing burden on the healthcare system. Current solutions are insufficient for young patients and do not offer relief from reintervention. Tissue engineered heart valves (TEHVs) offer a solution that grows and responds to the native environment in a similar way to a healthy valve. Stem cells hold potential to populate these valves as a malleable source that can adapt to environmental cues.Areas covered This review covers current methods of recapitulating features of native heart valves with tissue engineering through use of stem cell populations with in situ and in vitro methods.Expert opinion In the field of TEHVs, we see a variety of approaches in cell source, biomaterial, and maturation methods. Choosing appropriate cell populations may be very patient specific; consistency and predictability will be key to long-term success. In situ methods are closer to translation but struggle with consistent cellularization. In vitro culture requires specialized methods but may recapitulate native valve cell populations with higher fidelity. Understanding how cell populations react to valve conditions and immune response is vital for success. Detrimental valve pathologies have proven to be difficult to avoid in early translation attempts.