Researchers develop chip-like cell-sorting system

 

Benjamin Yellen, an associate professor of mechanical engineering and materials science at Duke’s Pratt School of Engineering, and his collaborator, Cheol Gi Kim of DGIST, printed thin electromagnetic components similar to those on microchips onto a slide. The patterns create magnetic tracks and elements like switches, transistors and diodes that guide magnetic beads and individual cells tagged with magnetic nanoparticles through a thin liquid film, a process much like that of a random access memory chip, though it moves cells instead of electrons. Localized rotating magnetic fields then move the beads and cells in specific directions etched into a track, while built-in switches direct them to storage sites on the chip.

 

The team demonstrated a 3-by-3 grid of compartments in the study that allowed magnetic beads to enter, but not leave; tagging the cells with magnetic particles and storing them in different compartments enable the separation, sorting, storage, study and retrieval of the cells.

 

“Our idea is a simple one,” said Kim in a press release. “Because it is a system similar to electronics and is based on the same technology, it would be easy to fabricate. That makes the system relevant to commercialization.”

 

“Most experiments grind up a bunch of cells and analyze genetic activity by averaging the population of an entire tissue rather than looking at the differences between single cells within that population,” Yellen added. “That’s like taking the eye color of everyone in a room and finding that the average color is grey, when not a single person in the room has grey eyes. You need to be able to study individual cells to understand and appreciate small but significant differences in a similar population.”

 

The researchers now plan to demonstrate a larger grid of 8-by-8 or 16-by-16 compartments with cells, and then to scale it up to hundreds of thousands of compartments. If successful, their technology would lend itself well to manufacturing, giving scientists around the world access to single-cell experimentation.

 

Moving forward, the researchers plan to demonstrate larger grids of 8-by-8 or 16-by-16 compartments with cells, then scale up from there to hundreds of thousands of cells. that kind of scale is necessary, according to Yellen, who noted that “You need to analyze thousands of cells to get the statistics necessary to understand which genes are being turned on and off in response to pharmaceuticals or other stimuli. And if you’re looking for cells exhibiting rare behavior, which might be one cell out of a thousand, then you need arrays that can control hundreds of thousands of cells.” He cited cancer and HIV as just such diseases, as both can present with cells that remain dormant and avoid destruction during treatment before activating at a later date, the situation that causes remission.

 

“Our technology can offer new tools to improve our basic understanding of cancer metastasis at the single cell level, how cancer cells respond to chemical and physical stimuli and to test new concepts for gene delivery and metabolite transfer during cell division and growth,” Kim added.

 

The research received support from the National Science Foundation, the Research Triangle Materials Research Science and Engineering Center and the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future Planning.

 

 

SOURCE: Duke University press release