|A new paper scheduled for publication in the January issue of Nature Photonics describes the use of spinning microparticles to direct the growth of nerve fiber, a discovery that could allow for directed growth of neuronal networks on a chip and improve methods for treating spinal or brain injuries.
Samarendra Mohanty, an assistant professor of physics at UT Arlington, is a co-author of the paper, which is now available online.
The study is based on Mohanty's hypothesis that neurons can respond to physical (e.g. fluid flow) cues in addition to chemical cues. He conducted the seminal work and observed that a laser-driven spinning calcite microparticle could guide the direction of neuron growth. Its rotation caused a shearing effect by creating a microfluidic flow.
Mohanty's work led the University of California, Irvine team led by professor Michael Berns to test the vaterite "micro-motors" in guiding neurons.
"This is the first report to demonstrate that neurons can be turned in a controlled manner by microfluidic flow," Mohanty said. "With this method, we can direct them to turn right or turn left and we can quickly insert or remove the rotating beads as needed. But flow can be generated by any means. In the body, for example, it will be more convenient to use a tube carrying fluids."
The researchers in the UC Irvine experiments used a laser tweezers system to trap a birefringent particle (calcite or vaterite) near axonal growth cones, which are the tips of neurons where connections are made with other neurons or cells. The same laser causes rotation of the particle, which creates the flow, Mohanty said.