Cells grown on microfibers may help treat brain injuries

Engineers are testing a new way to fabricate microfibers that support cell growth. The tiny fibers could be useful tools for reconnecting nerves and regenerating other damaged tissues.

“Neural stem cells on our polymer fibers could survive, differentiate, and grow,” says Nastaran Hashemi, an Iowa State University assistant professor of mechanical engineering.

The microfibers are flexible, biocompatible, and biodegradable. (Credit: Iowa State)

“These new fibrous platforms could also be used for cell alignment, which is important in applications such as guiding nerve cell growth, engineered neurobiological systems. and regenerating blood vessels, tendons, and muscle tissue,” Hashemi says.

The research team’s findings were recently published in Biomacromolecules.

Hashemi says the project is being funded by the Office of Naval Research in an effort to learn more about traumatic brain injury.

“We are interested in understanding how shock waves created by blows to the head can create microbubbles that collapse near the nerve cells, or neurons in the brain, and damage them,” Hashemi says.

Less damage to cells

“Our approach to fiber fabrication is unique,” Hashemi says. “There is no high voltage, high pressure, or high temperatures. And so one day I think we can encapsulate cells within our fibers without damaging them.”

The Iowa State researchers have developed an approach that uses microfluidic fabrication methods to pump polycaprolactone (PCL) through tiny channels to produce microfibers. The fibers are 2.6 to 36.5 millionths of a meter in diameter. Their shapes can be controlled. So can their surface patterns. They’re also flexible, biocompatible, and biodegradable.

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“The novelty here is the fabrication method,” Hashemi says. “We employ hydrodynamic forces to influence the orientation of molecules for the fabrication of these fiber structures that have different properties along different directions.”

The team demonstrated that neural stem cells were able to attach and align on the microfiber scaffold.

“In this study, cell death was minimal, and cell proliferation was affected by changing the features of the fibrous scaffold,” the researchers report in their paper.

That finding has the researchers thinking their technology could be a tool that helps tissue engineers find ways to regenerate nerve cells and other tissues.

“By mimicking the microenvironment of the nervous system, regeneration can be enhanced due to biological and chemical cues in the environment,” the researchers write in their paper. “In addition, the PCL fibers can be applied in regeneration of other tissues such as muscle, tendons, and blood vessels.”

The project also received funding from the US Army Medical Research and Materiel Command.

Source: Iowa State University