Plants could become miniature drug factories in space

The challenge of medication stability in space poses a significant hurdle for long-duration missions. On Earth, many drugs have a shelf life of five years, but in the microgravity environment of the International Space Station, over half of stored medications expire within three years. This limited stability is insufficient for missions like a journey to Mars, where even a one-way trip takes at least six months, making regular resupply missions logistically prohibitive.

Scientists are exploring a novel solution: using plants as miniature pharmaceutical factories in space. Genetically modified or even naturally occurring plants can produce complex therapeutic compounds using only light, water, and soil. This approach bypasses the need for large, sterile tanks required for traditional drug manufacturing. Furthermore, plants are already being cultivated in space for air and water recycling, a function that will become increasingly critical for extended missions.

Researchers have demonstrated the feasibility of this concept using an experimental compound, the CPMV virus, which stimulates the immune system to target cancer cells. A key difficulty has been extracting these compounds from plants. Traditionally, leaves are ground into a mixture, making product separation complex and requiring extensive equipment. The new method, inspired by secretion processes in bacteria and mammalian cells, simplifies this significantly. Plants secrete compounds into their apoplast, the space within the leaf. By immersing leaves in a buffer solution under reduced pressure and then restoring normal pressure, the fluid containing the virus particles is extracted. The leaves remain undamaged, allowing the plant to continue producing more.

This extraction method is efficient and scalable, with researchers successfully collecting and purifying CPMV from over 50 plants in less than two hours. The technique was also tested under simulated space conditions, including microgravity and temperature fluctuations mimicking cosmic radiation. Interestingly, some stresses even increased CPMV yield, suggesting that stressed plants may become more susceptible to infection, a trait inherent to the virus. This innovative approach holds promise not only for space exploration but also for resource-limited regions on Earth.