‘Out-of-this-world’ liver tissue grown in space could transform organ donation

In a significant step forward for tissue engineering, scientists are employing the microgravity environment aboard the International Space Station (ISS) to create human liver tissue with superior functionality.

Unlike the traditional Earth-bound approach that uses synthetic frameworks to guide cell growth, the microgravity environment allows cells to self-assemble naturally.

As a result, the liver tissues formed in space show enhanced differentiation and functionality compared to those grown in terrestrial conditions.

Microgravity: A game-changer for tissue engineering

On Earth, artificial scaffolds or culture plates are used to provide a structure for cells to grow, but these foreign materials can interfere with cellular function. In space, however, the absence of gravity allows cells to float freely and self-organize without the need for external matrices.

This results in tissues that more closely mimic natural physiology, a key factor in creating viable implants for medical purposes.

“Our findings indicate that microgravity conditions enable the development of liver tissues with better differentiation and functionality than those cultured on Earth,” said Dr. Tammy T. Chang, a professor of surgery at the University of California, San Francisco.

“This represents a critical step toward creating viable liver tissue implants that could serve as an alternative or adjunct to traditional liver transplants.”

“Tissue Orb” and cryopreservation

A central component of the project is the development of a custom bioreactor, known as the “Tissue Orb,” which is specifically designed to support tissue self-assembly in space. This bioreactor features an artificial blood vessel system and automated media exchange, simulating the natural blood flow and nutrient exchange that human tissues experience in the body.

By replicating these conditions in the microgravity environment, the team hopes to create more functional tissues suitable for transplantation or other medical applications.

One of the major challenges the team faces is preserving and transporting the engineered tissues back to Earth. To address this, the research includes developing advanced cryopreservation techniques. The next phase of the project will test isochoric supercooling, a method that allows tissues to be stored at sub-freezing temperatures without causing cellular damage.

If successful, this preservation method could significantly extend the shelf life of the engineered tissues, making them viable for transport and use in a range of medical scenarios, including disease modeling, drug testing , and ultimately, therapeutic implantation.

Future implications

This project is set to pave the way for future advancements in space-based biomedical research and manufacturing. The ability to grow complex tissues in microgravity offers a novel approach to tissue engineering— it could transform the production of other biological materials in space.

Additionally, the research aims to explore how these advancements could eventually be applied to whole organ preservation, potentially solving one of the biggest challenges in organ transplantation: the limited availability of viable organs.

The spaceflight experiment is slated for launch in February 2025. This collaboration highlights the increasing role of space exploration in advancing biomedical research, offering exciting opportunities for both space and Earth-based medical science.

The experimental results of this study will be presented at the American College of Surgeons (ACS) Clinical Congress 2024 in San Francisco, California.