Human Stem Cells Grown on Plants

William L. “Bill” Murphy, M.S., Ph.D., a professor of biomedical engineering at the University of Wisconsin, Madison, creates tiny scaffolds made of plastic or rubber on which he grows human stem cells.

To grow clusters of human stem cells that mimic organs in the lab and might be used someday in tissue implants, Bill Murphy, has, in the past, created tiny scaffolds for the cells made of plastic or rubber.

The task of the three-dimensional scaffolds is to support the cells, feed them, help them organize and allow them to communicate.

One spring day in 2014, Murphy looked out his office window onto the university’s Lakeshore Nature Preserve, and saw structures that do those very things naturally: plants.

Now, three years later, Murphy and Gianluca Fontana, a UW-Madison post-doctoral fellow, have grown skin, brain, bone marrow and blood vessel cells on cellulose from plants such as parsley, spinach, vanilla and bamboo.

Plants could be an alternative to artificial scaffolds for growing stem cells, the researchers reported in their article on their work in the journal Advanced Healthcare Materials.

“Rather than having to manufacture these devices using high-tech approaches, we could literally pick them off of a tree,” said Murphy, co-director of the UW-Madison Stem Cell and Regenerative Medicine Center. He said that the strength, porosity and large surface area of plants could prove superior to making scaffolds than are the current methods, using 3-D printing and injection molding.

“Plants have a huge capacity to grow cell populations,” Murphy said. “They can deliver fluids very efficiently to their leaves…. At the microscale, they’re very well organized.”

There are many species of plants to choose from. After Murphy’s inspirational gaze out the window, he and Fontana tested plants as scaffolds for stem cells using varieties they could easily obtain: parsley, spinach, jewelweed, water horsetail, summer lilac and softstem bulrush.

Then Fontana asked John Wirth, Olbrich Biotanical Gardens’ conservatory curator, about other species that might work. Wirth invited Fontana to walk through the tropical greenhouse and take samples back to his lab.

“I had never had a request like this before; it made me look at plant material in a different way,” Wirth said. “I think it’s a fantastic way of using these pieces of living tissue, to grow human tissue.” Olbrich plants that proved useful include vanilla, bamboo, wasabi, elephant ear, zebra plant and various orchids.