3-D printed models of heart, arteries developed

Researchers have used a new inexpensive 3-D printing method to develop models of heart and arteries out of biological materials.
The advance could one day lead to a world in which transplants are no longer necessary to repair damaged organs, researchers said.
"We've been able to take MRI images of coronary arteries and 3-D images of embryonic hearts and 3-D bioprint them with unprecedented resolution and quality out of very soft materials like collagens, alginates and fibrins," said Adam Feinberg, an associate professor at Carnegie Mellon University.
"We should expect to see 3-D bioprinting continue to grow as an important tool for a large number of medical applications," said Jim Garrett, Dean of Carnegie Mellon's College of Engineering.

Traditional 3-D printers build hard objects typically made of plastic or metal, and they work by depositing material onto a surface layer-by-layer to create the 3-D object.
Printing each layer requires sturdy support from the layers below, so printing with soft materials like gels has been limited.

"The challenge with soft materials - think about something like Jello that we eat - is that they collapse under their own weight when 3-D printed in air," said Feinberg.
"So we developed a method of printing these soft materials inside a support bath material. Essentially, we print one gel inside of another gel, which allows us to accurately position the soft material as it's being printed, layer-by-layer," he said.

One of the major advances of this technique, termed FRESH, or "Freeform Reversible Embedding of Suspended Hydrogels," is that the support gel can be easily melted away and removed by heating to body temperature, which does not damage the delicate biological molecules or living cells that were bioprinted.
As a next step, the group is working towards incorporating real heart cells into these 3-D printed tissue structures, providing a scaffold to help form contractile muscle.
Bioprinting is a growing field, but to date, most 3-D bioprinters have cost over USD 100,000 and require specialised expertise to operate, limiting wider-spread adoption, researchers said.

Feinberg's group, however, has been able to implement their technique on a range of consumer-level 3-D printers, which cost less than USD 1,000 by utilising open-source hardware and software.
The study was published in the journal Science Advances.