The Revolutionary Power Offered by Culturing Stem Cells in Space
The out-of-this-world superpowers of stem cells
Stem cells have the potential to change the face of medicine, whether that be by treating widespread deadly diseases, increasing the efficiency of transplants and reducing the possibilities of rejection, or studying the nature of a given illness and safely testing drugs. Stem cells are truly extraordinary.
However, we have yet to see the results of their abilities due to obstacles within the field, including inefficiency during transplantation, differentiation, and proliferation. These problems have challenged scientists for decades, but a solution has finally been suggested. The long-awaited benefits may not be delayed for much longer. No matter how out-of-this-world it may sound, sending stem cells to space could considerably increase the efficiency of their development and transplants while truly revolutionizing medicine.
Stem Cells
Stem cells are essentially templates for all other cells — they act as a repair system and have the ability to develop into various different cell types, depending on what is needed by the body. They are characterized by two main qualities: they can self-renew, meaning they can continuously divide to create more cells, and they can differentiate into different types of cells. It is this feature that gives stem cells the potential to treat a variety of diseases, as they have the ability to become any cell, ranging from brain cells to heart cells; from blood cells to muscle cells.
As stem cells become more specialized towards a specific type of cell, their pluripotency, or ability to become a variety of cells, reduces. Pluripotency is crucial as it is the key for scientists to be able to convert stem cells into cells of their choosing, making them as specific as possible to a patient's disease. Currently, pluripotent stem cells are most often found in the embryo. However, the practice of using genetic factors to convert normal cells into stem cells is also used (iPSCs).
The Potential of Stem Cells
With these features, not only can stem cells convert into disease or patient-specific cells, they can be grown and used for research. They can even be used to develop tissue and organs.
Here are some examples of how stem cells have been used:
- There are 100,000+ organs that patients are waiting for in North America alone. This can be addressed by combining 3D bioprinting technology and cutting-edge stem cell research to print organs. Some simpler organs, like the bladder, have already been printed for patients.
- Differentiating stem cells into cells that do not replicate, like neurons, which can then be used to treat neurodegenerative conditions like Alzheimer's or Parkinson’s
- Creating better and more permanent treatment options for diseases like diabetes, such as transplanting insulin beta cells
Advancements in this area of technology are crucial for the future of medicine, but development remains incredibly slow.
Stem Cells on Earth vs. In Space
Over 90% of unspecialized stem cells die when transplanted. This is on Earth, a standard gravity environment.
In space, however, there is a microgravity environment. This does not mean there is no gravity, but rather the environment where you may see objects floating around. This environment is caused by the continuous free fall of objects, and when everything falls at the same rate, it appears as though everything is weightless.
Studies have shown that developing cells in a microgravity environment, such as on the ISS, can lead to a 46% increase in viability in cells than in standard gravity environments. This means that developing stem cells in space is much more effective, and can produce quantities that simply are not possible on Earth.
Studies of Stem Cells in Space
Scientists have examined the effects of growing cells in a microgravity environment in contrast to a standard gravity environment. Here are a few examples of studies that prove that developing stem cells in space is more efficient than on Earth:
Progenitor Cardiac Cells
The cells were first developed as Induced Pluripotent Stem Cells (iPSCs) and then into a type of heart cell. The cell formations of both cells were very similar in the observations from after a few days up to after a week. After around 20 days, there was a significant change in the cells from the microgravity environment. The majority of these heart cells were shown to be beating together, whereas only some of the cells from the standard gravity environment were beating. Looking closer, on the twentieth observation day, the microgravity culture also had 99% α-actinin positive cells. This is a protein encoded by the ACTN2 gene expressed in cardiac muscle, which helps anchor muscle proteins and increases the efficiency of heart contractions.
Viability and Purity
In the following study, the viability was analyzed with a diagnostic marker for carcinoma known as EMA (epithelial membrane antigen), as cells that were affected and negative cells. Up to 90% of cells in the microgravity environment were identified as negative (or live), compared to only 56% of cells in the standard gravity environment.
Additionally, in the following three studies which analyzed purity, the cells in the microgravity environment consistently had higher percentages of α-actinin compared to the standard gravity cultures.
Overall Results & Transportation
Overall, the results of the microgravity vs. standard gravity cell cultures displayed very clear results. The cells returned with greater quantities, purity, and viability. The cardiomyocytes from the study returned with a 90% viability, as well as an increase in regulation of the genes associated with viability after differentiation and proliferation. To be transported back to Earth, the stem cells or organoids (small groups of cells) would need to be in low-turbulence, temperature-controlled environments with a sufficient amount of oxygen.
Companies Working on Sending Stem Cells into Space
- Most notably, scientists at Cedars-Sinai are working to send stem cells to the ISS to experiment with their development in microgravity environments. They focus on disease modeling, the development of products from stem cells, and bio-fabrication.
- CELLINK and Uppsala University have sent bio-printed neural crest stem cells into space with hopes to study microgravity environments. Researchers have found that when cultured with the neural crest stem cells, insulin-producing cells show better growth and function. The company hopes to develop these in space to introduce new treatment options for type 1 diabetes.
- The International Space Station itself also has a special lab solely for stem cell research. In the spring of 2020, UCSD and Space Tango received a grant from NASA to build the Integrated Space Stem Cell Orbital Research (ISSCOR). Scientists believe that in the microgravity environment, the cells will show better growth and can more effectively develop as 3D structures.
Helping Humans on Earth and Space
Stem cell research in space will not only help accelerate medicine on Earth, but it will help study life in space. In astronauts specifically, studies have shown how space travel can destroy a significant amount of red blood cells, as well as affect other bodily functions in different ways. Stem cells will aid in understanding the human body and life on different planets, while further developing space technologies to make life in space possible.
The Future
The first stem cells, derived from heart cells, were sent to space in 2016 to study microgravity environments. More studies will be done in the next few years to further study the efficiency of developing stem cells in space. By combining the innovation of space technologies and the possibilities of stem cells, the potential of stem cells increases significantly, along with the potential of treating and understanding disease.
TL;DR
- Stem cells are characterized by two main qualities: they can self-renew, meaning they can continuously divide to create more cells, and they can differentiate into different types of cells. They hold the potential to treat and study a variety of diseases.
- Over 90% of stem cells die when transplanted in Earth’s standard gravity environment. However, studies completed in the microgravity environment in space have shown a 46% increase in the viability of cells than in standard gravity environments. This means that developing stem cells in space is much more effective, and can produce quantities that simply are not possible on Earth.
- Studies with progenitor cardiac cells have shown significant differences in the viability, purity, and function of cells cultured in space in comparison to Earth. When they are transported back to Earth in low-turbulence, temperature-controlled environments with a sufficient amount of oxygen, the cells have greater quantities as well.
- Companies like Cedars-Sinai and CELLINK are working to make this goal a reality. The International Space Station also has a special lab specifically for stem cell research known as the Integrated Space Stem Cell Orbital Research (ISSCOR).