THURSDAY, Aug. 1, 2019 (HealthDay News) — Scientists say they have taken an important step forward in creating 3-D printed hearts — with the ultimate goal of making replacement tissue for organs and body parts damaged by disease or injury.
The 3-D printing process builds three-dimensional objects based on a computer model. Unlike traditional printing onto a flat surface, the machines churn out various materials — plastics, metals, ceramics — layer by layer.
The technology is used in various industries, and in recent years researchers have been developing an offshoot: 3-D “bioprinting.” The hope is to eventually have the capacity to produce custom-made replacement tissue, or even whole organs, for patients.
Of course, the human body is far more complicated than a consumer product. Not only does printed tissue need structure, it needs to be permeated by blood vessels, nerves and other elements that keep it alive.
Researchers are years away from bioprinting functional organs that can be transplanted into humans, said lead researcher Andrew Lee.
But he and his colleagues at Carnegie Mellon University in Pittsburgh are reporting a key step on that long road. They’ve developed a new bioprinting method capable of creating parts of the human heart out of collagen.
Collagen is the most abundant protein in the body, and it’s a critical part of the “extracellular matrix” — a network of molecules that surround your body cells, giving them structure and chemical support.
The new bioprinting strategy helps address a major obstacle: Printing living cells and soft biological material, like collagen, is difficult. Collagen starts out as a fluid, and would just end up in a puddle if bioprinted by itself, the researchers explained. But by supporting the collagen with a gel that can be removed after the bioprinting is done, the collagen has time to solidify.
The technique is dubbed FRESH 2, and with it the researchers were able to reliably print tiny collagen fibers, of 20 micrometers in diameter — an order of magnitude smaller than the previous 250 micrometers with an earlier version of the technology. The approach also allowed them to solidify the collagen with precise control — creating tissue “architectures” that can be embedded with living cells.