Author: Suzie Mishima
Artist: Shangyu Chen
Editor: Haytham Malik
Have you ever wondered what goes on up in the International Space Station? The ISS National Lab, a remarkable scientific outpost since its inception, has served as a vibrant centre for advancing the field of biotechnology for almost 20 years. What sets it apart as arguably the most unique laboratory in the universe is one distinct attribute – microgravity.
Microgravity is a near-zero gravity environment, which, simply put, is the sense of weightlessness that an astronaut would experiences in space. This results from the constant freefall of the ISS in Earth’s orbit whereby the speed of orbit is so fast that all masses in this orbit are constantly falling. In microgravity, traditional rules governing physical processes on Earth no longer apply. Gravity is a force that we take for granted and without it, fundamental biological processes behave differently.
Tissue Engineering
Even within our bodies, the effects of microgravity wield considerable influence on our health, triggering the degradation of muscle, bone, and cartilage. These physiological changes present formidable challenges to the prospects of space exploration, prompting dedicated research to combat these issues. Tissue engineering and regenerative research under microgravity has been an exciting opportunity into understanding how these conditions can be treated, since for example, cartilage tissue has limited regenerative potential. Some studies suggest that stem cell derived cartilage tissue growing under microgravity conditions display remarkable capabilities in proliferation, differentiation, and the overall production of superior quality tissue. At this intersection of space science and regenerative medicine, these breakthroughs raise optimism for the potential use of artificially grown cartilage tissues in microgravity as viable replacements for deteriorated cartilage.
Protein Crystals
Microgravity has also been instrumental in the field of drug discovery by reimagining approaches to the tried-and-true technique of X-ray crystallography. This may sound familiar as it was the key to discovering the structure of DNA back in 1952, and is still used to this day in revealing the structures of proteins for drug development. X-ray crystallography reveals a molecule’s 3D shape by concentrating X-rays on a crystalized sample of the molecule, which, after mathematical analysis, reveals the precise arrangement of its atoms. Despite being an established technique there are inherent limitations that deem certain protein structures to be ‘unsolvable.’ Gravity is one of the culprits as it creates convection currents as the protein molecules interact with each other during crystallisation, which results in defective crystals. Enter microgravity–here, the absence of these disruptive currents allow protein molecules to randomly arrange themselves, fostering the creation of more organised, high-quality crystal structures.
A drug to combat Duchenne Muscular Dystrophy (DMD), a severe disease of muscle degeneration, has been developed based on a protein crystal revealed aboard the ISS. Phase 3 trials are currently underway, with the hope that the drug, TAS-205, could double the lifespan of DMD patients. Other projects aiming to decipher the specificities of drug targets such as the elusive breast cancer Bax inhibitor-1 hope to develop better treatments.
Drug delivery
Once a drug has been developed, a critical challenge emerges: – how to effectively deliver a drug to maximise efficacy. In 2019, Aphios Corporations secured access to the ISS to pioneer the development of drug-encapsulating particles on the pico-scale. These ‘picoparticles’ were designed to deliver a leading Alzheimer’s drug candidate known as Bryostatin-1, to the brain. Through microgravity, they were able to reduce the size of a typical nanoparticle from 88 nm to less than 3 nm. A smaller particle is desirable as it can penetrate the blood brain barrier, as well as reduce dose per treatment due to high surface area to volume ratio. Aphios’ ambitious objective is large-scale manufacturing of these picoparticles to treat Alzheimer’s, all while curbing costs per dose through microgravity technology.
Future in Microgravity Research
Last year, NASA unveiled the decision to decommission the International Space Station (ISS) in 2031, marking a pivotal moment in space exploration. Does this mean the end of microgravity research? The growing commercialisation of space suggests otherwise as private companies, including Elon Musk’s SpaceX, are set to replace the ISS. Although microgravity research is still in its early days, the demonstrated potential of the ISS has generated unprecedented interest in microgravity in this new frontier of biotechnology.
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