Scientists Rebuilt Functional Components Of Human Heart Using 3D Printing Technology

Biofabrication technology, widely used in medical research, supports scientists in creating vascularized and innervated complex organs to better integrate with the surrounding tissues for implantation. Otherwise, these constructs can be used to study mechanisms and possible therapies behind pathological conditions or organ regeneration.

Due to these practical applications, biofabrication is aimed to develop tissue scaffolds, dealing with life-threatening diseases such as end-stage renal failure. Scientists across the world have made various attempts to realize the concept but see certain obstacles. And from now, the situation has changed, as researchers from Carnegie Mellon University successfully fabricated tissue components of the human heart at multiple length scales using a 3D printing technology named FRESH.

The solutions of FRESH

Before the invention of FRESH, 3D bio-printing has reached major milestones including micro-physiological devices, patterned tissues, and more. However, micropatterning of living cells, as well as soft biomaterials like extracellular matrix (ECM) proteins has proved intricate. The resolution and accuracy required to regenerate complex 3D function and structure made it difficult for scientists to process these soft and dynamic biological materials. That’s where FRESH comes in.

FRESH – short for Freeform Reversible Embedding of Suspended Hydrogels – provides the solution for 3D bio-printing collagen with precise adjustment of composition and microstructure. With technology, scientists are able to construct human heart components, from small blood vessels to beating ventricles.

For so long, collagen is considered an ideal substance for biofabrication. However, gelation in collagen, which is thermally driven self-assembly, restrained scientists from rebuilding complex scaffolds from the chemical’s native form.

They have tried different approaches such as chemically transforming collagen into the ultraviolet (UV) or adjusting PH and temperature, but still failed to achieve the necessary accuracy. Meanwhile, FRESH enables researchers to make use of unmodified collagen as a bio-ink by using rapid change in PH which drives collagen self-assembly within a thermoreversible support bath consisting of a gelatin microparticle slurry.

The results of testing FRESH (v2.0)

The 3D printed heart constructed through FRESH has precisely regenerated human-specific anatomical structure based on human MRI. The model of the cardiac ventricles using human cardiomyocytes also showed synchronized contractions, directional wave propagation, and wall thickening up to 14%.

However, there remain some challenges for the team to overcome such as generating the sufficient number of cells which are required to create large tissues, establishing a regulatory process for clinical translation, and achieving manufacturing scale. The three-dimensional human heart is considered the proof-of-concept, promising the capability of generating advanced scaffolds from native tissues, thus applying the technology to a larger clinical scale in the near future.

The copyright owner of FRESH

FRESH is currently licensed to FluidForm whose founders led Carnegie Mellon University team of researchers in developing the technology. FluidForm is now focusing on designing advanced applications of FRESH technology in biofabrication, regenerative medicine, and others. LifeSupport appears as the first product of the company which allows for FRESH 3D bio-printing of soft hydrogel bio-inks in complex geometries without the need for sacrificial support inks, or ink modifiers to increase mechanical stability.

“The FRESH technique enables bio-printing researchers to achieve unprecedented structure, resolution, and fidelity. We are very excited to be making this technology available to researchers everywhere”, said Mike Graffeo, FluidForm CEO.