Challenges for astronauts on space exploration missions

Prolonged space travel is becoming an important goal for humanity, especially as missions take off Moon Mars and beyond are being planned by space agencies across the globe. However, with the scientific and technical benefits that space exploration brings, scientists also face a series of physiological challenges. One of the biggest problems is the negative impact of the microgravity environment on the human body, including cardiovascular health.

Previously, studies have shown that when people live in a zero-gravity environment for a long time, the body’s organs can experience many changes. From muscle atrophy, loss of bone density, vision changes, to psychological problems, all have been documented in astronauts returning from the International Space Station (ISS). Now, a new study led by scientists at Johns Hopkins University has made a disturbing discovery: The human heart is also weakened by living in space.

Special experiments on the ISS

This study was performed on bioengineered human heart tissue samples. In the experiment, 48 tissue samples were sent to the International Space Station for 30 days to test how microgravity affects heart muscle cells. This could help scientists better understand how the heart functions in microgravity and what changes may occur at the cellular and molecular levels.

The results showed that, when in a microgravity environment, heart muscle cells not only become weaker, but also have difficulty maintaining a rhythmic beat. Heart cells develop arrhythmias – a common symptom seen in people with age-related cardiovascular problems. Notably, these changes occurred after only a short period of exposure to the space environment, suggesting that microgravity may have a stronger impact on cardiovascular health than previously thought.

“Heart on chip” and technology platform

The research team led by Deok-Ho Kim, professor in the Department of Biomedical Engineering at Johns Hopkins University, and his colleagues developed a “heart on a chip” platform to serve this experiment. The platform uses human-made pluripotent stem cells, which have the ability to turn into many different cell types, including cardiomyocytes. These cells are placed on a miniature bioengineering chip, simulating the way an adult human heart works.

Then, these heart tissue chips were brought to the ISS on a SpaceX flight in March 2020. Here, astronaut Jessica Meir took care of the experiment on behalf of the research team, maintaining living conditions for the heart tissues by changing the nutrients around them weekly. Tissue samples are also preserved for genetic and imaging analysis when they return Earth allowing the research team to collect comprehensive data on how microgravity affects the contractions and rhythmic functioning of the heart.

This experiment is a major step forward in heart health research in space. Unlike previous experiments that only focused on the physiological effects of microgravity on the astronaut’s body, this time the research team focused on the cellular and molecular level, helping us better understand how the space environment affects heart muscle function.

Unexpected results

Data from the “heart on a chip” experiment shows that in a microgravity environment, heart muscle cells lose their ability to contract strongly. Earth . Tissue samples developed arrhythmia, with the time between beats lasting nearly five times longer than the normal beat of a healthy heart. This is particularly worrying because it suggests that not only is myocardial strength impaired, but the rhythmic function of the heart is also seriously affected.

One of the other key findings was that bundles of proteins in heart muscle cells, called sarcomeres – responsible for heart muscle contraction – became shorter and less organized than in control cells. This is a sign of damage to the heart, similar to what is commonly seen in patients with age-related cardiovascular disease.

In addition, the mitochondria – the energy-producing parts of cells – of the heart tissue samples became larger, rounder and lost their characteristic folds, disrupting the energy production process. This reduction in energy production may explain why cardiomyocytes are significantly weakened in microgravity.

Not stopping there, heart tissue samples also showed an increase in markers of inflammation and oxidative stress, especially an imbalance between free radicals and antioxidants. These markers not only show the effects of microgravity but are also consistent with what we know about aging and cardiovascular disease in the world. Earth .

Applications and future

The findings from this experiment have important implications for both astronaut health and medical research Earth . First, they help expand our understanding of how microgravity affects the human body, especially cardiovascular health. This will help space agencies, such as NASA, develop health protection measures for astronauts on future long-duration missions.

In 2023, Kim’s lab sent another batch of heart tissue samples to the ISS to test drugs that could protect the heart muscle from the negative effects of microgravity. This is an important step forward that not only helps maintain cardiovascular health for astronauts, but could also open up new therapies to treat cardiovascular disease for those on board. Earth .

In addition, Kim’s research team also cooperates with NASA to study the effects of space radiation on cardiovascular health. Radiation from cosmic rays and the sun is one of the major risks astronauts will face when moving out of orbit. Earth where the planet’s magnetic field shields them from much of the cosmic radiation. Understanding the effects of this radiation will help scientists develop preventive and protective measures for astronauts’ cardiovascular health during space missions.

New research into the impact of microgravity on cardiovascular health shows that long-term space living not only affects the body superficially but also has a profound impact on the cellular level. Changes in the function and structure of the myocardium in the space environment pose great challenges for space exploration missions. Earth but at the same time, it also opens up new opportunities to research and develop new therapies for cardiovascular diseases Earth .

Advances in biotechnology, tissue engineering and space medicine not only help protect the health of astronauts but could also bring major advances in medicine for all of humanity. With these important discoveries, the future of space travel will become increasingly safer and more efficient, bringing humans closer to conquering distant planets.