Researchers from the Carnegie Mellon University, Pittsburgh have found an alternative to heart transplants by creating models of heart through 3D printing using soft biological materials.

In contrast to other parts of the body, heart tissues once damaged are unable to recover themselves. However, this new study, the research team says, triggers hope of building a world one day where transplants will be unnecessary for repairing damaged organs.

Traditional 3D printers manufacture hard objects generally made of plastic or metal and printing each layer needs the support of a solid material beneath it. Owing to this necessity, researchers so far have ruled out the idea of utilizing soft materials like gels for 3D printing.

"3D printing of various materials has been a common trend in tissue engineering in the last decade, but until now, no one had developed a method for assembling common tissue engineering gels like collagen or fibrin," TJ Hintin, a student at Carnegie and the lead author of the study, said.

Adam Feinberg, an associate professor at Carnegie and one of the researchers of the study revealed that they were successful in taking "MRI images of coronary arteries and 3D images of embryonic hearts and 3D bioprint them with unprecedented resolution and quality" out of collagens and fibrins, according to the study.

Feinberg explained that the difficulty with soft materials such as "Jello that we eat – is that they collapse under their own weight when 3D printed in air." Therefore, the research team invented a new technique through which they 3D printed the soft materials of collagens and fibrins "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 added.

One of the significant breakthroughs of this novel method, known as "Freeform Reversible Embedding of Suspended Hydrogels" (FRESH), is that the support gel beneath the soft material can easily be melted away and discarded by heating in normal body temperature, without impairing the delicate biological materials that were 3D printed.

Feinberg and his team, has not only used a unique way of 3D printing, but they have also been successful in making the procedure inexpensive. According to the study, "most 3D bioprinters have cost over $100,000 and/or require specialized expertise to operate; limiting wider-spread adoption."

Nonetheless, Carnegie researchers conducted their research on a variety of consumer-level 3D printers for less than $1,000 with the usage of "opens-source hardware and software."

The research team is now working towards implementing actual heart cells into these 3D printed tissue materials in order to give a support for forming contractile muscles.

The study has been published in the journal Science Advances.