Aging slower in space?
Microscopy application in mini-space satellite to study human cells
The importance of space exploration is growing, with more and more astronauts cavorting in space. But what effects does weightlessness have on the aging of the human body? How do certain cells develop under milligravity and microgravity conditions, such as those found on small moons and asteroids? The Swiss Artificial Gravity Experiment (SAGE) is dedicated to this research task. A team of students from different Swiss universities (Academic Space Initiative Switzerland ARIS) wants to investigate how the aging process in humans changes in space and how cellular senescence influences the development of aging and age-related disorders. Currently, the young researchers are designing the construction of a satellite platform for a corresponding biological experiment, which must meet extreme requirements. The fully automated system will serve as a long-lived test site under the required space conditions and act as a centrifuge for the human cell lines to be studied. At the heart of this CubeSat solution is a fluorescence microscope equipped with a microfluidic chip and a high-resolution USB3 camera from the uEye XLE family.
The SAGE Cubesat has to withstand strong physical stresses during the ascent into space and later the radiation and temperature fluctuations.
In the human body, aging processes take place at the cellular level, which are referred to as senescence. This is a phenomenon in which cells stop dividing and secrete inflammatory factors. "Building on research by NASA and many other groups around the world, there is reason to believe that cells age more slowly in zero gravity than on Earth. This effect can be measured by certain proteins and mRNA, which are emitted during cell aging. Messenger RNAs (mRNAs) have emerged as essential factors contributing to or preventing cellular senescence. A fluorescent marker can be used to label this mRNA, and when irradiated with the right light, it will glow. The complete experiment is performed over a period of two months in a volume of only ten cubic centimeters. To measure and analyze the necessary processes under these conditions, we need a particularly reliable and compact fluorescence microscope," explains SAGE Payload Engineer Jonas Schlör.
Fluorescence microscope with USB3 uEye XLE board level camera from IDS. The screen shows the cells captured by the camera.
A U3-38J1XLE-C-HQ was used in the microscope for the laboratory tests. The camera captures fluorescent mRNA from human cells placed on a microfluidic chip. Microfluidic chips enable miniaturization and integration of complex laboratory functionalities on a single chip. This saves space and reduces sample requirements. Microfluidic chips contain engraved or shaped microchannels through which the fluid to be analyzed can flow. The use of microfluidic channels allows samples to be run in very small volumes. The high resolution of the camera with Sony's IMX415 rolling shutter sensor allows individual cells to be distinguished from one another. In particular, the high pixel density of the sensor makes it possible to display individual cells with a diameter of only 15 μm. A blue LED energizes the cells in a microfliodic chip. These emit varying amounts of green light depending on the rate of senescence. Cells with higher senescence rates emit more fluorescent proteins and are therefore brighter. An optical filter allows only the green light from the cells to pass through the lens onto the camera. This allows not only to determine the general senescence rate of the cells, but also the specific number of living cells.
"The camera features numerous software-related setting options, such as exposure times or color filters, which allows for maintaining a high degree of flexibility throughout the design process."
— JONAS SCHLÖR, SAGE PAYLOAD ENGINEER —
Microscope scheme for cell research with uEye XLE camera, microfliodic chip and LED
The cells emit different amounts of green light depending on the senescence rate.
"The data obtained are thus very meaningful and scientifically relevant, as comparable research has not been conducted in this way before," explains Jonas Schlör. In addition, a complex apparatus, which is otherwise necessary for fluorescence microscopes, can be dispensed with at the same time and a lot of space can be saved. "The camera also features numerous software-related setting options, such as exposure times or color filters, which allows a high degree of flexibility to be maintained throughout the design process." In addition, it must meet the harsh requirements of the external environment. These include the rocket launch with its very intense vibrations and, of course, the conditions in orbit under vacuum and cosmic radiation.
With 8.41 MPixels and 4K resolution, the U3-38J1XLE Rev.1.1 is particularly suitable for this form of visualization tasks. With the 2x2 binning feature, it is possible to reduce the amount of data to be transferred by a factor of four if necessary, thereby increasing both the light sensitivity and the frame rate. Sony's IMX415 rolling shutter sensor delivers high-resolution data for detailed image analysis. Due to its extremely space-saving design, the IDS camera can be optimally integrated into this embedded application. The camera is controlled by a microcontroller, which processes and compresses the data while still on the satellite, after which it is to be sent to Earth. The software as well as the control algorithms are developed and tested by the students of the Swiss Academic Space Initiative themselves.
High resolution USB3 camera of the uEye XLE family from IDS
The requirements for the system or the CubeSat are high: The latter must both provide the attachment points for the subsystems and components and ensure the structural stability of the satellite - from insertion into its launch vehicle to the end of its service life. All components must be able to withstand the physical stresses generated by the launch vehicle during ascent and later the radiation and temperature fluctuations in space, while being as light as possible. The satellite prototype has already delivered promising initial results.
The experiment is designed for 3 years. Based on the research results, various scenarios are conceivable. First, for example, the scientists would like to find out whether certain therapies could improve the astronauts' well-being. But senescent cells can also be drivers of various diseases that make life difficult for people, especially in old age - such as dementia, arteriosclerosis, diabetes and arthritis. In addition, they are suspected of contributing to tumor progression. According to one study, SARS-CoV-2 may also be a trigger for senescence - a possible explanation for Long Covid's persistent symptoms.
The Swiss Artificial Gravity Experiment could provide interesting approaches for possible therapies. More and more IDS cameras are thus making a contribution to health promotion worldwide. "An area of operation that is close to our hearts," emphasizes IDS founder and owner Jürgen Hartmann.