Aerospace medicine – how do blood vessel cells behave in space?
The German SPHEROIDS experiment is on its way to the International Space Station
On 8 April 2016, at 22:43 CEST, the German SPHEROIDS experiment was launched to the ISS in a Dragon capsule on board a Falcon 9 rocket of the US aerospace company SpaceX. With this experiment, funded by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and flying to the ISS with a European Space Agency (ESA) 'ticket', scientists from the University of Magdeburg want to investigate the effects of microgravity on human blood vessel cells (vascular endothelial) that form the innermost layer of human blood vessels. These cells line each of our blood vessels, perform a crucial control of the functionality of the vascular walls and play an important role in regulating blood pressure and the growth of muscle cells, as well as in coagulation and inflammatory processes.
Test tube blood vessels
"The main objective of SPHEROIDS is to find out how endothelial cells grow in the absence of gravity and develop into more complex structures and tissues, so-called three dimensional spheroids. This involves fundamental medical questions, for example, about the genetic programming of these cells and the key molecules of such developmental processes in the human body," explains Markus Braun, the SPHEROIDS project manager at the DLR Space Administration in Bonn. Long-duration stays in space are a challenge for the astronauts' skeletal muscles, immune system and cardiovascular system. The health problems that can arise after spending long periods in microgravity conditions are caused, among other things, by changes in endothelial cells.
"Achieving an understanding of the mechanisms and functioning of endothelial cells under microgravity conditions, and determining the growth processes of these cells would be a major success," Daniela Grimm elaborates, who is Professor for Gravitational Biology and Translational Regenerative Medicine at Magdeburg University. She adds: "With this knowledge, medical professionals can develop completely new treatments for circulatory diseases." Researchers hope to use the results of the SPHEROIDS experiment to be able to cultivate the smallest blood vessels in a test tube. These tiny veins could be used for transplants. "It would thus be possible to conduct tests with pharmaceutical substances, which would reduce the number of tests on animals," says Grimm.
The first 3D structures form in just a few hours
The endothelial cells are contained in eight experiment chambers during the two-day Dragon capsule flight to the ISS. Once the capsule arrives at the Space Station, the astronauts will place the chambers in an incubator in the European Columbus Laboratory. The cells will grow for approximately one week and reproduce themselves under microgravity conditions. One set of the experimental cells will be automatically chemically fixed on the seventh day. Another set is provided a nutrient solution and is allowed to grow on the ISS for another seven days before also being fixed. This procedure ensures that the specimens can no longer change before they are analysed at the laboratory at University of Magdeburg.
In similar experiments, it was possible to observe that 3D structures form within a very short time. The first tiny spheroids – globular-shaped heaps of cells – with a circumference of about 0.3 millimetres formed after only a few days. Most of the specimens had formed spheroids after five days, and some of the specimens even began to grow into vein-like structures.
After about 30 days in space, the endothelial cells will be returned to the home laboratory in Magdeburg, where the molecular and biochemical analysis will begin. SPHEROIDS is funded by the DLR Space Administration with funds from the German Federal Ministry for Economic Affairs and Energy.