High-flying Experiment: Do Stem Cells Grow Better in Space?

Researcher Dhruv Sareen’s own stem cells are now orbiting the Earth. The mission? To test whether they’ll grow better in zero gravity.

Scientists at Cedars-Sinai Medical Center in Los Angeles are trying to find new ways to produce huge batches of a type of stem cell that can generate nearly any other type of cell in the body — and potentially be used to make treatments for many diseases. The cells arrived over the weekend at the International Space Station on a supply ship, The Associated Press said.

“I don’t think I would be able to pay whatever it costs now" to take a private ride to space, Sareen said. “At least a part of me in cells can go up!"

The experiment is the latest research project that involves shooting stem cells into space. Some, like this one, aim to overcome the terrestrial difficulty of mass producing the cells. Others explore how space travel impacts the cells in the body. And some help better understand diseases such as cancer.

“By pushing the boundaries like this, it’s knowledge and it’s science and it’s learning,” said Clive Svendsen, executive director of Cedars-Sinai’s Regenerative Medicine Institute.

Six earlier projects from the US, China and Italy sent up various types of stem cells — including his team’s study of the effects of microgravity on cell-level heart function, said Dr. Joseph Wu of Stanford University, who directs the Stanford Cardiovascular Institute. Wu helped coordinate a series of programs on space-based stem cell research last year.

Earthly applications of much of this research may be a little ways off.

At this point, the only stem cell-based products approved by the Food and Drug Administration contain blood-forming stem cells from umbilical cord blood for patients with blood disorders such as certain cases of lymphoma. There are no approved therapies using the kind of stem cells being sent to space or others derived from them, said Jeffrey Millman, a biomedical engineering expert at Washington University in St. Louis.

But clinical trials underway involving stem cells target conditions such as macular degeneration, Parkinson’s disease and heart attack damage. And Millman is involved in research that could lead to a new approach for treating Type 1 diabetes.

Scientists see great promise in stem cells.

THE GRAVITY DILEMMA
That promise is tempered by a frustrating earthly problem: The planet’s gravity makes it tough to grow the vast quantities of cells necessary for future therapies that may require more than a billion per patient.

“With current technology right now, even if the FDA instantly approved any of these therapies, we don’t have the capacity to manufacture” what's needed, Millman said.
The issue? In large bioreactors, the cells need to be stirred vigorously or they clump or fall to the bottom of the tank, Millman said. The stress can cause most cells to die.
“In zero G, there’s no force on the cells, so they can just grow in a different way,” Svendsen said.

The Cedars-Sinai team has sent up what are called induced pluripotent stem cells. Many scientists consider them the perfect starting materials for all sorts of personalized, cell-based treatments. They carry a patient’s own DNA, and their versatility makes them similar to embryonic stem cells, only they are reprogrammed from adults' skin or blood cells.

For their experiment, which is being funded by NASA, a shoebox-sized container holds bags filled with spheres of cells and all of the pumps and solutions needed to keep them alive for four weeks. The cargo will also include neural stem cells originating from Svendsen. The scientists used stem cells derived from their own white blood cells because it was easy for them to give consent.

They will run the experiment remotely with a box of cells on Earth for comparison. They'll get the space experiment back in five weeks or so, when it returns in the same SpaceX capsule.

The work is designed to pave the way for more NASA-funded research. If they are able to figure out how to make billions of cells in orbit, Svendsen said, “the impact could be huge.”

A HIGH-FLYING FUTURE
During the same cargo launch, researchers from the University of California, San Diego, sent blood stem cells to the space station, a repeat of an experiment they did last year. They want to find out if low Earth orbit induces faster aging in the cells, leading to problems that set the stage for precancerous changes. One goal is to protect astronauts' health.

Afshin Beheshti, a researcher at NASA Ames Research Center, said scientists are just beginning to understand some of the risks of space travel.

“There’s more unknowns in space than there are knowns," he said. “Any new type of experiment is going to shed light on how the body responds to the space environment.”

Ultimately, Beheshti said, the research should yield more than practical, earthly solutions like new medicines. It will also help with far-off human aspirations, like living on other planets.

Faced with temperatures dipping to -30 Celsius (-22 Fahrenheit), visitors to China's wintertime resort city of Harbin often make a beeline for stalls selling padded clothing to augment their wardrobes.

Oddly perhaps for some, frozen ice cream bars are also considered a key part of the visit.

Each winter, the industrial city in China's northeast turns into a magnet for those from China's balmier regions wanting to experience the extreme cold and take in the sculptures built from ice blocks carved from the Songhua River, which freezes from late October to late March.

“I searched for tips on the internet and am now wearing knitted wool pants and the thickest sweater possible,” said Jin Yiting, who was visiting with her parents from the financial hub of Shanghai, where a light jacket is usually sufficient winter garb.

Jin Yanlong runs a stall selling winter hats, gloves and boots in the park. He said that most of his customers are tourists from southern China who underestimate the frigid weather in Harbin.

“Some of the tourists wear ‘too thin.’ They come here immediately from the airport. They would find us to buy warm trousers padded with cotton,” Jin said.

Despite the freezing weather, some curious tourists are brave enough to taste the cold itself. Zhuang Chang and his friend enjoyed their Madie’er ice cream bars while strolling on a commercial street whose architecture reflects the Russian influence on the city. The brand was established in 1900s by a Russian company and has steadily grown in popularity among tourists.

“It’s cold, but my heart is warm,” Zhuang said. He also compared the humid cold months of his hometown in Zhejiang province, where “people would be frozen to the core when being hit by wind.”

“But here only my hands and face feel cold,” Zhuang said.

For those seeking a warmer alternative, there are hot drinks and steaming hot pot, a kind of stew mixing meat, vegetables, tofu and other favorites.

Restaurant owner Chi Xuewen claims to own the world's largest hot pot, where 18 individual pots featuring a variety of flavors circle the giant bowl.

“Eating anything in a hot pot makes people warm,” Chi said.

Li Long’s restaurant uses wood both to cook the food and warm the air in the ice block structure.

“The pot also radiates heat,” Li said. “Once the pot cover is lifted, customers see the hot food. In one word, it just feels hot.”

Prolonged cold has left local residents with few options for fresh vegetables, so frozen food has become an alternative. Frozen tofu left outside overnight becomes porous and is particularly good at soaking up soup and flavor, local resident Liu Xiaohui said.

High-flying Experiment: Do Stem Cells Grow Better in Space?