Inventor of ‘ghost heart’ suggests using pig scaffolding filled with stem cells instead of pig heart transplant.

Inventor of 'ghost heart' suggests using pig scaffolding filled with stem cells instead of pig heart transplant.

The Remarkable Journey to Creating “Ghost Hearts”

ghost heart

Doris Taylor, a scientist working in regenerative medicine and tissue engineering, has made groundbreaking strides in the field. Her most notable achievement is the creation of what she calls “ghost hearts” – personalized functioning human hearts grown in a lab, potentially eliminating the need for donor organs.

Taylor recently spoke at the 2023 Imagine Solutions Conference in Naples, Florida, sharing her insights on the ghost heart and her remarkable journey in developing it. In this article, we will delve into the details of her work and the potential impact it can have on organ donations.

The Challenges of Organ Donation Today

Currently, the organ donation system faces significant challenges. Patients in need of heart transplants are placed on a waitlist, and organs become available only when someone else has died. Due to the scarcity of donor hearts, only the most critically ill patients are prioritized. In the United States alone, there are over 3,000 people waiting for a heart transplant, while the country performs approximately 11 heart transplants daily.

Even when successful transplants occur, they often come with a host of medical complications and diseases. The drugs needed to prevent organ rejection can lead to high blood pressure, diabetes, cancer, and kidney failure. These conditions have far-reaching effects, impacting individuals emotionally, financially, and physically. Shockingly, around 18% of transplant recipients die within the first year after the procedure.

The Mystery Behind Ghost Hearts

A “ghost heart” is essentially a heart without cells, only consisting of the heart’s framework or scaffolding. This name derives from the heart turning from red to white after the cells are removed. While human hearts cannot serve as scaffolding due to their scarcity, Taylor’s team discovered an alternative – pig hearts. Pig hearts share similarities with human hearts in terms of size and structure, making them ideal for this innovative approach.

To create a ghost heart, the pig heart is subjected to a process called perfusion decellularization. Through this method, the heart is washed with a mild detergent, removing all cellular material. The resulting cell-free heart can then be seeded with new cells, typically from the patient receiving the transplant, effectively personalized for each individual.

The Power of Stem Cells in Heart Creation

Stem cells play a crucial role in the creation of a functional heart. Unlike heart cells, stem cells can divide and transform into specialized cells, in this case, heart cells. Dr. Shinya Yamanaka, a Nobel Prize laureate, discovered a method to generate stem cells from adult blood or skin cells. Taylor’s team utilized this technique to obtain a significant number of stem cells, which were then differentiated into heart cells using specific chemicals.

Although witnessing heart cells beating in a dish was a groundbreaking moment, these cells alone do not constitute a functional heart. To truly become a heart, they need to be placed within a form that allows them to grow and mature, eventually leading to the ability to pump blood. In the human body, this development occurs naturally during embryonic development. To replicate this process in the lab, Taylor and her team had to recreate the necessary environmental conditions.

Rethinking Pig-Heart Transplants

In 2022, a significant event occurred in the field of organ transplantation – a genetically engineered pig heart was successfully transplanted into a human. While this breakthrough showed promise, it came with limitations. The patient still had to take anti-rejection drugs that suppressed their immune system, and unfortunately, an undisclosed pig virus within the heart led to the patient’s demise merely two months after the transplant.

Taylor believes her ghost heart approach can overcome these challenges. By removing all pig cellular material, leaving only the protein structure and blood vessel channels behind, her team effectively avoids potential rejection issues. The proteins within the scaffold closely resemble human proteins, minimizing the risk of rejection and related complications.

Overcoming the Challenges of Ghost Hearts

Creating ghost hearts presents two significant hurdles for Taylor and her team. Firstly, the process of growing the necessary cells is time-consuming and costly. Growing and differentiating billions of heart cells requires extensive resources and expertise. Secondly, once the cells are delivered into the scaffold, the heart needs to mature and function independently, all while maintaining sterility without antibiotics.

To ensure the heart’s maturation, the team has had to recreate an artificial human body, which they refer to as a “biocradle.” This biocradle provides essential nutrients, temperature control, oxygen, and artificial blood flow. The immature heart cells must be trained to work together, grow strong enough to pump blood, and maintain sterility without the presence of a natural immune system. This complex orchestration resembles a symphony, where each piece must come together at the right time for the creation of a beautiful, functional heart.

Paving the Way for Future Organ Donations

Looking ahead, Taylor envisions a future where organ donations no longer lag behind the demand. Scientists are working tirelessly to increase the number of donors, rejuvenate organs that were previously considered unusable, and develop innovative technologies like ghost hearts. However, it is crucial to address the issue of access and equality in organ transplantation. Currently, the system disproportionately fails people of color, leading to significant health inequities.

As science continues to progress, there is hope for universal access to organs and the elimination of toxic drug dependency following transplants. Taylor is dedicated to driving this change and aims to transform heart transplants from emergency procedures to planned hospital surgeries, making them more accessible and equitable for all.

The development of ghost hearts represents a perpetual effort, requiring a dedicated team and support from various stakeholders. By building hearts earlier in the process, we can revolutionize the field of organ transplantation and ensure a brighter future for those awaiting life-saving procedures.

Doris Taylor is a Regenerative Medicine Lecturer at the University of New Hampshire.

This article is republished from The Conversation under a Creative Commons license. Read the original article.