Overview of China's space life science and biotechnology achievements

In 1994, the Dynamic Cell Culture System (DCCS) jointly developed by the Shanghai Institute of Technical Physics of the Institute of Zoology successfully carried out satellite experiments. In the late 1990s, the study of the physiological effects of weightlessness evolved from an early observation of phenomena to an in-depth discussion of mechanisms. In October 2003, the successful launch of China's manned spacecraft Shenzhou V showed that China's manned space program has taken a big step forward. Subsequently, China has carried out "Shenzhou 6", "Shenzhou 7" and "Shenzhou 9" manned spaceflight, from the original astronaut to three astronauts, and China's first female astronaut Liu Yang smoothly flew into space.

"Shenzhou VI" carried out the astronauts themselves as physiological tests. The researchers installed a variety of sensors on the two astronauts to record their metabolism during space flight, feel the feeling of weightlessness, test the tolerance of the human body in the space environment, and collect data such as water and gas supply and household garbage excretion. The data of human movement and force performance in weightless environment are obtained, which provide important basis for the design of space station.

Shenzhou-9 carried out 10 human science experiments, including the impact of space flight on vestibular eye movement, cardiovascular and advanced brain functions; Study on cytological mechanism of protection against physiological effects of weightlessness; Research on prevention technology of spatial bone loss; Hazardous gas collection and analysis; Astronaut mass measurement in orbit; Study on pharmacokinetics of paracetamol in weightless condition; Astronaut sleep wake biological cycle rhythm monitoring. In September 2010, China's space station mission was officially launched, marking the breakthrough of China's manned space program to achieve short-term flight to long-term in-orbit residence.

The Shenzhou spacecraft series carries a series of life science experiment projects, which is a leap in the development of space life science in China. In 2002, the Shenzhou IV spacecraft "space cell electric fusion" conducted the space fusion experiments of tobacco "Innovation No. 1" protoplasts and yellow flower tobacco devacuolar protoplasts and mouse myeloma cells and lymphoB cells respectively, obtained the fusion cells and measured the fusion rate of cells under space microgravity conditions, as well as the ability of tobacco fusion cells to regenerate plants.

In 2006, the "Research on the growth and Development of Higher Plants in Space Confined Ecosystem" of the "Shijian 8" recoverable satellite orbiter obtained real-time image data from various stages of seed germination, seedling growth and flowering. It provides a new basis for understanding important physiological processes such as vegetative growth, flower bud differentiation and reproductive organ formation of higher plants in space environment.

On the Shenzhou VIII spacecraft in 2011, China and Germany carried out 17 scientific experiments in four major fields using a universal biological incubator developed by the German side. The four fields cover scientific research issues such as basic space biology, space biotechnology, basic biology of advanced life support systems, and space radiation biology. Among the 17 scientific experimental projects, 10 are conducted by China, 6 by Germany, and 1 by Sino-German cooperation.

After 90 years, the research mainly focuses on five aspects: 1. Spatial protein crystal growth technology and structural biology; 2, space cell and tissue culture technology (including space biomechanics and engineering); 3, space cell electric fusion technology; 4, space biological macromolecule separation (space electrophoresis) technology; 5. Space biology effect. The research in the first stage mainly explores technical issues, and also develops research methods to test the reliability and practicability of space hardware, laying the foundation for future scientific and technological innovation research.

3. Main research achievements of China's space life science and biotechnology

3.1 Crystal growth of proteins and other biological macromolecules

A living body is a precise and efficient machine assembled by proteins, nucleic acids and other biological macromolecules, and even an organelle or a group of proteins is a delicate molecule/nanomachine, which work together to complete a variety of physiological functions. After the study of human genome, structural genome/proteome has become the focus of life science research. Many proteins are difficult to study deeply because of the lack of high-quality single crystals. Growing high-quality protein crystals and obtaining the fine structure of protein molecules by X-ray diffraction can reveal the relationship between their biological functions (normal physiological effects, pathogenic mechanisms, pharmacodynamics or side effects) and molecular structure. Therefore, it has a direct effect on molecular drug design and is of great significance to biomimetic biotechnology. The microgravity environment in space can provide a more ideal growth environment for protein crystals than that on the ground: when protein crystal growth is carried out on the ground, due to the slow diffusion of protein molecules, solute poor layer will be formed around the protein crystal in solution, and natural convection of solute will be further generated under the induction of gravity. Convection destabilizes the crystal growth environment, increases the chances of impurities approaching the crystal surface, and destroys the hydrated layer of protein molecules. In addition, the heavier protein crystals will produce sedimentation, collision and accumulation adhesion, etc., which will reduce the quality of the crystals. In the microgravity environment of space, convection and sedimentation will be effectively inhibited, the crystal growth environment will be more stable, the short-range order of the solution will be stronger, the hydration (solvation) degree of protein molecules will be increased, the filtration and purification function of the poor layer will be effectively exerted, crystal collision and adhesion will rarely occur, and the wall effect will be effectively inhibited. Thus, larger and higher quality protein crystals can be grown, thus laying the foundation for obtaining finer molecular structures and thus more precise structure-function relationships (structure-activity relationships of drugs). After 30 years of research, space protein crystallization has developed into one of the most important space biotechnology, and is an important research content on the International Space Station ISS. Using the ISS, the United States space shuttle, the former Soviet Union's "Mir" space station and spacecraft, China's Shenzhou spacecraft and scientific experiment satellites and other spacecraft, researchers from the United States, Japan, the European Union, Russia, Canada and other countries have carried out hundreds of space experiment studies, and obtained the crystal structure of nearly 30 proteins, nucleic acids, viruses and so on. China's research in this field is almost synchronized with that of foreign countries, led by the Institute of Biophysics of the Chinese Academy of Sciences, and innovative research results have been achieved in molecular assembly mechanism and experimental methods and technologies.