Second-by-second the countdown clock ticks down. It’s December 6, and Siobhan Malany, Ph.D., and a team of two dozen scientists, engineers and implementation partners have gathered on a causeway inside Kennedy Space Center to watch the launch of SpaceX’s Falcon 9 rocket. More than 6,500 pounds of research and supplies are on board the cargo capsule destined for the International Space Station, or ISS, including a lab-on-a-chip experiment from the University of Florida College of Pharmacy.
Tension runs high amongst the group. A day earlier, NASA postponed the launch due to poor weather conditions. The team doesn’t want a repeat, but high clouds drifting over launch pad 39A threaten another postponement.
Each passing minute offers a subtle reminder of the 18-month journey to reach this crescendo. An interdisciplinary team led by Malany, an associate professor of pharmacodynamics in the UF College of Pharmacy, built a miniaturized laboratory that plugs into the ISS and allows scientists to study live human cells in space. The shoebox-sized experiment will help scientists understand microgravity effects on human muscle cells and could aid in the development of new therapies for age-related muscle loss on Earth.
“Astronauts experience extreme muscle weakness in space, and similar muscle changes occur when people age on Earth, although at a much slower pace,” Malany said. “If you study age-related incidences, you have to look over many years to see changes. In space, the microgravity effect accelerates muscle mass changes. Our experiment should provide some great insight into muscle cell biology and why tissues respond differently in space.”
For Malany, this is her third launch of a lab-on-a-chip research experiment to the space station. Previous space missions in 2014 and 2018 set the stage for the latest flight, which expands the science to include more human skeletal muscle cells and collect new data around microgravity-induced muscle loss.
The Final Countdown
With five minutes until launch, the high clouds begin drifting away. NASA began fueling the rocket 30 minutes earlier, and the final safety checks are underway. Several team members are watching NASA TV’s broadcast on their cell phones, while others are fixated on the launch pad five miles away.
The pageantry typically surrounding a rocket launch is subdued by the ongoing COVID-19 pandemic. Kennedy Space Center has closed its gates to outside observers – leaving a scattering of research teams spanned out across the property to observe the launch.
When UF’s experiment plugs into the International Space Station, an automated tissue chip system will feed nutrients to 3D muscle bundles four times a day. Tiny electrodes built into the chips allow scientists to study muscle contractions, while a microscope camera system moves on a rail above the chips collecting images and data.
The experiment features 16 skeletal muscle cells loaded onto the chips. Half the cells were biopsied from a young cohort under 40, while the other half were collected from adults over 60. Additionally, half the cells in each group will receive electronic stimulation prompting muscle contractions, while the others will not.
“We want to see if there is a difference between young and old cells over time and compare how the cells react to electronic stimulation,” said Shelby Giza, a biological scientist in the UF College of Pharmacy and project scientist for the space research mission. “When the cells return from space, we’ll run the same experiment on the ground, so we can compare results between Earth and microgravity.”
At 11:17 a.m., the countdown clock reaches zero and plumes of smoke emerge from the 215-foot tall Falcon 9. The rocket lifts with a trail of fire thrust from its nine engines. The anxiety-filled final moments before launch transition into a sense of celebration, as a wave of relief overwhelms Malany and the team. They watch intently as Falcon 9 ascends higher and higher, until the rocket’s only visible reminder is the trail of smoke streaking across the sky.
“It’s been challenging and nerve-wracking these last few months, and the team has put in long hours to get us to this point,” Malany said minutes after the launch. “But it’s exciting to know our experiment is now on a rocket bound for the International Space Station.”
SpaceX’s Dragon cargo ship would arrive at the space station the next day. Malany’s experiment has reached its final destination and the microgravity experiment is about to begin.
Science in Space
Tissue-chip experiments in space are very much at the frontier of science. An individual chip, similar in size to a human thumb, contains cells that mimic major organs and systems in the body. Malany’s previous space mission in 2018 featured two tissue-chips, but the 2020 mission has 16.
The experiment begins when the first round of nutrients is fed to the cells. More than 250 miles below on Earth, Malany and the team closely watch the flow rate in real-time. A sophisticated software platform allows scientists to track temperature, pressure, humidity and a multitude of other factors inside the system. A camera mounted inside the box captures pictures and videos of the tissue movements – offering important visual data of cells response to feeding and stimulation.
For 10 straight days, the process repeats itself. Along the way, there would be setbacks — such as bubbles forming in the tubes responsible for feeding nutrients to the cells — and major milestones, including the first real-time electronic stimulation video captured in orbit.
The experiment ends a few days before Christmas. Data collected from the mission will take months to analyze, but early indications show the older and younger cohort of cells contracted at different rates in space.
“The older cells appear to be thinner than the young cells, so there are some apparent morphology differences,” Malany said. “I’m ecstatic that the initial biology looks so great and these cells were viable for the length of time that they were in space. Even with fluctuations in temperature and flow, the 3D tissues held together really well. This suggests we can run longer duration experiments in microgravity.”
Back on Earth the genetic material collected from the cells will be used in future studies. Meanwhile, Malany is already planning her next two space missions, with an eye on adding drug compounds — that work to prevent muscle atrophy in animals — to the tissue-chip experiment in fall 2022.