Scientists at University of California, Irvine developed a new way to sort through stem cells based on their electric charge properties.
The technique used by the scientists, called dielectrophoresis, is based on the premise that different types of cells have different electric properties. Stem cells that are destined to become neurons, for example, have a different electric charge than stem cells that will become astrocytes, another type of brain cell. The scientists discovered that the cells react differently when electric fields are applied. At one frequency, a neuron will be attracted to an electrode but an astrocyte will not, and at a different frequency, an astrocyte will be attracted but a neuron will not.
Identifying and sorting stem cells is important when creating stem cell-based therapies. Without a purification process, stem cell transplantations can cause tumors or be rejected by the body’s immune system.
In this study, the scientists wanted to identify and collect stem cells that were destined to become neurons, which are cells in the brain and spinal cord that process and transmit information. Neurons that die as a result of injury or disease do not regenerate, which is why people with neuronal loss suffer problems such as paralysis and memory loss. Scientists believe that stem cell transplantations might be able to restore part of the lost function.
With the goal of identifying future neurons, UCI engineers built a tiny device using a glass slide to perform the dielectrophoresis. First, scientists place unsorted mouse stem cells on one side of the device. The cells then float in sugar water through a tiny channel past electrodes set to a particular frequency. At a certain frequency, stem cells destined to become neurons will stick to the electrodes while other cells pass by. The cells that stick then can be removed and grouped together, potentially for use in a therapy.
Press release: UC Irvine scientists find new way to sort stem cells
