Candy floss leads to breakthrough for artificial organs
Candy floss machines may hold the key to designing life-sized artificial livers‚ kidneys‚ bones and other organs.
Assistant professor of mechanical engineering at Vanderbilt University‚ Leon Bellan‚ has been using candy floss machines to make networks of artificial blood vessels the size‚ density and complexity of human capillaries.
Capillaries are a complex network of blood vessels that deliver oxygen to cells and carry waste away.
Bellan bought his first candy floss machine at American supermarket Target for forty dollars and has been experimenting at making capillaries for years.
“Our goal is to create a basic toolbox that will allow other researchers to use this simple‚ low-cost approach to create the artificial vasculature needed to sustain artificial organs‚” Bellan said.
“Some people in the field think this approach is a little crazy.”
He has just announced that he was able to make vessels that sustained an artificial organ for a week.
Tissue engineering researchers use a gel similar to that of hair gel.
The gel needs to be able to be solid enough to transport liquids and also porous enough able to allow oxygen‚ waste and nutrients to diffuse through the capillaries.
Researchers sometimes build capillaries by layering cells in a gel and allowing them to grow. But sometimes the cells die before the network is fully formed.
Spinning out the cells with a candy floss type machine allows the network to be formed immediately.
Bellan is using a material known PNIPAM‚ a polymer that is insoluble at temperatures above 32 degrees‚ which is unusual. He spins PNIPAM to make a network. Then he mixes gelatin in water and adds human cells to the gelatin. The mixture of gelatin and human cells is poured over the PNIPAM structure and cooled.
Bellan says his method has made the vessels thin and complex enough to work in organs: “So far the other top-down approaches have only managed to create networks with micro-channels larger than 100 microns‚ about ten times the size of capillaries‚” he said.