Newly developed graphene biointerfaces have been shown to facilitate noninvasive stimulation of cells as well as provide surfaces more conducive to growth than plastic dishes or glass plates. According to researchers at University of California San Diego School of Medicine who developed this graphene-based system, it could improve drug discovery as well as medical device development. The advantages conferred by the graphene surface are derived from graphene’s ability to convert light into electricity, something plastic and glass, as insulators, can’t do.
"[I]n your body, you don't see many surfaces acting like plastic or glass," said first author Alex Savchenko, a research scientist in the department of pediatrics. "Instead, we're conductive. Our hearts are extremely good at conducting electricity. In the brain, it's electric conductivity that allows me to think and talk at the same time."
To demonstrate the potential of their system, which is described in the May 18 issue of Science Advances, the researchers generated heart cells from donated skin cells, via induced pluripotent stem cells (iPSC). Then they grew these iPSC-derived heart cells on a graphene surface.
According to Savchenko, it took the team awhile to pin down the optimal graphene-based formulation. Then they had to find the best light source and way to deliver that light to the graphene-cell system. But they eventually found a way to precisely control how much electricity the graphene generated by varying the intensity of the light to which they exposed it.
"We were surprised at the degree of flexibility, that graphene allows you to pace cells literally at will," Savchenko added. "You want them to beat twice as fast? No problem—you just increase the light intensity. Three times faster? No problem—increase the light or graphene density."
Savchenko and colleagues found they could likewise control heart activity in a living organism (zebrafish embryos) using light and dispersed graphene.
The team was also surprised at the absence of toxicity, which often presents researchers with a huge challenge. "Normally, if you introduce a new material in biology, you'd expect to see a certain number of cells killed in the process," Savchenko said. "But we didn't see any of that. It makes us hopeful that we'll be able to avoid harmful problems later on, as we test various medical applications."
For now, the team is focused on heart cells and neurons. But they are interested in eventually applying their graphene/light system to search for drugs that specifically kill cancer cells, while leaving healthy cells alone. The researchers also envision using graphene to find opioid alternatives—use-dependent pain medications that only work when and where a person is in pain, thus reducing systemic effects than can lead to misuse and addiction.