A surprising source of inspiration for spinning capillaries-like networks was found in the county fair darling, the cotton candy machine. A cotton candy machine spun material for growing artificial organs under the magic touch of Vanderbilt University researchers.
Engineering the perfect medium to support artificial cell development growing into tissue and organs proved a frustrating task. While hydrogel-based solutions have been found, they are reported to work only in close range. However, driven by the unorthodox idea to use a cotton candy machine, Leon Bellan, lead researcher on the project, found an effective breakthrough.
Bellan and his team authored the research paper featured in the Advanced Healthcare Materials journal. Thanks to the Vanderbilt University team, the stepping stone has been set for artificially creating kidneys, livers and other organs. A 40 dollars cotton candy machine purchased at Target helped the team create threads networks similar in complexity, density and size to capillaries-like networks.
Capillaries are essential for cell survival and tissue development. They deliver nutrients and oxygen for cell survival and eliminate waste. Engineering capillaries networks was essential for the next big step: creating artificial organs. With the help of the cotton candy machine, Leon Bellan and his team managed to create the three-dimensional capillaries network that supports cell survival, their viability and functionality for over a week.
Leon Bellan used water-based gel part of a class of popular materials in bioengineering called hydrogels. These materials proved highly efficient in acting as scaffolds for three-dimensional capillaries network. The properties of hydrogels may be tweaked to mimic the exact properties of the matrix ensuring cell survival and tissue development. Despite their ability to act as scaffolds, vital nutrients and oxygen may only travel thus far through this medium.
Against this background, the need to develop an intricate three-dimensional network of channels became more clear by the day. A cotton candy machine spun material for growing artificial organs using what Bellan calls a top-down approach.
According to researchers, the cotton candy machine produced threads from 3 to 55 microns, measuring 35 microns in diameter. Proving the efficiency of the cotton candy machine was the first step of the project. The second phase saw the research team experiment with several materials that could support cell and tissue development now that the basic capillaries-like network was in place.
The main goal is to be able one day to create artificial organs using this method.
The material found to be most suitable to create the vast network and offer it the strength to support cell survival is Poly(N-isopropylacrylamide) or PNIPAM. This is a polymer which is insoluble in water at temperatures exceeding 32 degrees Celsius.
The PNIPAM threads were created using a machine developed on the matrix of the cotton candy machine. Then, the researchers used gelatin to mix it with water and human cells. Adding transglutaminase helped the solution transform to gel. The mixture was added to the PNIPAM threads and placed at 37 degrees Celsius in an incubator.
When the PNIPAM threads with the mix were taken out of the incubator, the structure was allowed to cool off. As a result, the threads started dissolving, leaving behind in intricate network which allowed the researchers to pump cell culture medium through.
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