Researchers who have longed to grow artificial organs in a lab may have finally found some sweet inspiration: a cotton candy machine.
In the past there have been two approaches to trying to grow artificial organs; a bottom-up method where cells are left to grow their own capillaries and the top-down approach, where engineers create their own capillaries.
The first method can take weeks making it difficult to stack the cells high enough without starving the ones in the center. The latter method led to capillaries that were too large, the smallest being about 10 times the size of naturally occurring ones.
Thanks to a fateful trip to Target, a team at Vanderbilt University in Nashville has found another way.
Leon Bellan, an assistant professor of mechanical engineering, was researching the nanofiber-building process of electrospinning when he first attended a lecture about the need to create artificial vascular systems for engineered tissue. Electrospinning made fibers that resembled capillaries, and often these fibers were compared to silly string or cotton candy.
"So I decided to give the cotton candy machine a try," Bellan told Vanderbilt University News. "I went to Target and bought a cotton candy machine for about $40. It turned out that it formed threads that were about one-tenth the diameter of human hair—roughly the same size as capillaries—so they could be used to make channel structures in other materials."
Back in the lab, researchers used a device that spun threads of a cell-friendly polymer that can be coated in a gelatin mixed with human cells. The gelatin then goes into a warm incubator, which keeps the threads solid while the gelatin sets. Once it cools, the threads dissolve and leave behind a network of very tiny tunnels, or artificial capillaries.
With this structure in place, all scientists need to do is start pumping nutrients into the new organ and see if the cells survive. The study found that after a week, 90% of the human cells in their sample organ were still thriving.