Scientists have developed an artificial capillary system in 3D, that is taken from a most unlikely source, the cotton candy machine. This remarkable man made capillary system also has the ability to keep cells alive and functioning for more than one week.
The team led by mechanical engineer professor Leon Bellan of Vanderbilt University has been examining cotton candy machines to create tiny, complex networks of threads that are reminiscent of cotton candy fibers, which are just as dense as capillaries.
In this new study, the goal of this artificial fiber network template is for the future use of capillary systems found in life sized artificial organs.
To date, laboratories utilize thin sheets of hydrogels to create cells however, since they are water based, these gels can deliver nutrients and remove waste efficiently but only if they are really close to a nutrient and oxygen source for a waste sink to be produced in the process. It is also challenging to create a network of even thicker tissues where scientists need to develop a highly dense and complex network using fine channels. Bellan, who is also the lead author of the study, now used a conventional cotton candy machine to create these very fine channels.
In this new study, researchers developed and built a machine that functions like a regular cotton candy machine but instead of spinning ultra thin, delicate threads of sugar, it spins Poly (N-isopropylacrylamide) or PNIPAM, which is a special type of polymer, creating ultra fine clouds of PNIPAM.
When the PNIPAM clouds are created, a solution filled with human cells is poured over them, where the structure is left to form a gel inside an incubator with a temperature of 37 degrees. Using a common food enzyme called transglutaminase, this allows the clouds to transform into permanent gel.
After cooling in room temperature, the gel structure from the incubation process is now embedded with dissolved fibers that are left with complex micro channels. In order for the chemicals and oxygen to flow through this highly complex network, pumps were used to infuse with life supporting nutrients.
According to Bellan, after about several days, 90 percent of the cells that are perfused with these micro channels remained alive and functional as opposed to those 60 to 70 percent channels that were only working which were not perfused nor possess any microchannels.
Researchers hope to create a template or a "tool box" for making an artificial capillary system for other researchers to develop their own capillary systems that are required for artificial organs.
This new study is published in the journal Advanced Healthcare Materials.