Candy floss (also known as cotton candy) has been used by US scientists to create a web of microscopic tubes to mimic the capillary network that carries blood to human tissue. 

Leon Bellan at Cornell University's Nanobiotechnology Center, Ithaca, and colleagues, mimicked the capillary network structure by sticking two sugar rods to a candy floss ball. They poured a molten polymer over the candy floss, left it to solidify, then dissolved the sugar, leaving a complex network of channels connecting two larger inlet and outlet channels. They then injected fluorescently labelled blood into the system and followed its progress using a video fluorescence microscope. They found that the blood flowed through as it would in a real system.

Bellan's method addresses a limitation in tissue engineering: how to make an artificial vascular system for the new tissue. Since blood can only diffuse a few hundred micrometres from a capillary, organs need these networks to deliver oxygen and nutrients to every cell. His technique is cheaper and less time consuming than existing methods for making the networks, such as layer-by-layer 2D structure stacking or 3D printing, where templates for growing cells are built up.

Candy floss is an ideal template as it is cheap, non-toxic, water soluble and sticky. The stickiness allows junctions between the sugar rods and the candy floss to form easily. The only equipment required is a candy floss machine, which can be purchased for as little as $40 (approximately £30), says Bellan. 

'Finding inspiration from something in everyday life is very clever,' says Jeff Borenstein, director of the Biomedical Engineering Center at Draper Laboratory, Cambridge, US. 'It reminds me of how the pioneering tissue engineer, Jay Vacanti, was inspired to create 3D scaffolds for tissue engineering by observing the structure of seaweed while on a Cape Cod beach.' 

Bellan says that potential applications for his method, aside from helping to grow organs in the laboratory, could include making self-healing polymers that can fracture and heal, over and over again in the same place. 'The simplicity and low cost of this new fabrication technique should render many applications of 3D microfluidic networks commercially viable,' he says.

James Hodge

Enjoy this story? Spread the word using the 'tools' menu on the left or add a comment to the Chemistry World blog