Researchers develop 3D printed human heart pump

July 19, 2020 0 By FM

Researchers from the University of Minnesota have developed a 3D printed live beating heart muscle ‘pump’ using a specialised bio-ink made from extracellular matrix proteins and human-induced pluripotent stem cells (hiPSC).

3D bioprinting has been proposed as a means to generate more geometrically complex tissues with its ability to print cell-laden tissues composed entirely of native proteins or biocompatible synthetic components. Multiple studies have demonstrated the capacity to print entire heart organ models using biological materials, but most of the resulted constructs have either lacked cells or evidence of electromechanical function.

Cardiomyocytes do not proliferate or migrate readily which makes it challenging to achieve the high cell density required for the formation of functional cell-cell junctions while maintaining the structural support needed for an enclosed heart chamber.

Hence in this study, the team developed a bioink formulation using optimised photo-cross-linkable formulation using native extracellular matrix (ECM) proteins to 3-dimensionally print human induced pluripotent stem cell-laden structures with 2 chambers and a vessel inlet and outlet.

The team grew the stem cells within the structure until they reach an appropriate cell density, and then programmed them to differentiate into cardiomyocytes within the printed structures.

“At first, we tried 3D printing cardiomyocytes, and we failed, too,” said Brenda Ogle, a researcher involved in the study. “So, with our team’s expertise in stem cell research and 3D printing, we decided to try a new approach. We optimised the specialised ink made from extracellular matrix proteins, combined the ink with human stem cells and used the ink-plus-cells to 3D print the chambered structure. The stem cells were expanded to high cell densities in the structure first, and then we differentiated them to the heart muscle cells.”

The newly differentiated cells began to organise and work together. In fact, after culturing the structures for about a month, the cells began to beat together, as they would normally in the heart, say the authors. The team could develop a 1.5 cm sized structure that could pump fluids. The heart muscle model could be used to study heart disease and test new therapies.

“We now have a model to track and trace what is happening at the cell and molecular level in pump structure that begins to approximate the human heart,” said Ogle. “We can introduce disease and damage into the model and then study the effects of medicines and other therapeutics.”