What will it take before a bioengineered heart will be implanted in patients?

PURPOSE OF REVIEW: Heart transplantation is the only curative treatment option for end-stage heart failure. However, a shortage of donor organs is a major limitation of this approach. Regenerative medicine targets the goal of increasing the number of available hearts for transplantation. In this review, we highlight the state of the art of building a bioartificial heart. We summarize the components needed, the hurdles, and likely translational steps to make the dream of transplanting a totally functional bioartificial heart a possibility.

RECENT FINDINGS: The therapies being developed in regenerative medicine aim not only to repair, but also to regenerate or replace failing tissues and organs. The engineering of bioartificial hearts utilizing patient-derived cells could theoretically solve the two main complications of heart transplantations: graft rejection and lifelong immunosuppression. Although many hurdles remain, scientists have reached a point in which some of these hurdles have been overcome. Decellularized heart scaffolds have emerged over the past decade as one of the most promising biofabrications. Two possible options for organ scaffolds exist: nontransplantable human hearts and porcine hearts. The use of these scaffolds could lead to the availability of an unlimited number of transplantable organs. The current challenge remains improving processes required for recellularization - including those for cells, bioreactors, and physiologic conditioning. Researchers should focus to solve these hurdles and pave the way toward the dream of in-vivo bioengineered heart maturation.

SUMMARY: Regenerative medicine has emerged as one of the most promising fields of translational research and has the potential to both minimize the need for donor organs and increase their availability. Meeting the challenge of implanting a totally functional bioengineered heart lies in solving multiple issues simultaneously. Dwarfing the technical hurdles, cost is the largest barrier to success. The scientific hurdles mainly involve scaling up and scaling out of laboratory cell processes, building bioreactors, and delivering cells into every needed region of an organ scaffold. Maintaining sterility and quantifying readiness of the nascent organs are also critical for success.