They present a new method for 3D printing eyes and hearts.

“I only do the eyes,” Hannibal Chu tells humanoid replicant Roy Batty in the film. blade runner (Ridley Scott, 1982). “You are Nexus. “I designed your eyes,” he emphasizes in the middle of his icy bioengineering laboratory, completely different and less cold than that of Yifei Jin (University of Nevada-Reno, USA). This mechanical engineer spent years researching how make eyes using 3D printing. But also the most diverse bioprinting of living tissues. Now his team has just unveiled a new method for creating biocompatible organs, from eyes to entire hearts or parts of them.

3D printing of tissues and organs Man is not something new, but is still in experimental territory. Its functionality is limited by large-scale limitations of printing methods. There are different approaches: from printing with “living” tissues to artificial substances, but they are easy to tolerated by the body.

Yifei Jin and his colleagues presented PNAS a method for 3D printing replacement organs such as eyes or coronary valves on a multi-scale scale. Biological dye is printed on the fabric. photocurable. The authors developed a yield stress fluid composed of nanoclay particles and a temperature-sensitive polymer to support structures during printing.

Inject liquid to create 3D printed eyes or corneas.

Using a kind of elastic liquid bath, the authors dynamically adjusted the height of the printed fabric layer to obtain cornea with a smooth surface. Everything, on a scale of just a few micrometers. By adding liquid as needed, the authors created structures in the shape of a human eyeball with a retina, lens and optic nerve.

They also produced aortic heart valve And heart humans on a large scale. However, at the moment its use is far from clinical practice. According to the authors, the method can be used in medical training, surgical planning, disease modeling and sensor manufacturing portable or wearable and soft robotics.

Are we facing a future robot heart? Or the eyes of a replicant? It is not so easy

3D bioprinting: history goes back more than 20 years and is still little used in clinical practice

You should go back to 1988 talk about the background of bioprinting. Then it was hardly possible to have the simplest tissues, but with cells. The idea, developed by the University of Texas, was to use adapted classic inkjet printers. But it wasn’t until 2002 that Anthony Atala of Wake Forest University created the first model of the organ, a nonfunctional mini-kidney.

Since then, different prototypes have been developed until 3D printing of eyes was developed. But each of them faces a difficult task: vascularizationthat is, these organs can be irrigated by the circulatory system and can “live” inside the body, just as our organs do.

In this sense, prototypes have been developed, such as the one by Jennifer Lewis (Wyss Institute for Biological Engineering, Harvard University) in 2016 or another based on spinach leaves with which it was possible to vascularize a model of the human heart and which was presented by Worcester Polytechnic Institute (USA) in 2017.

Another approach is to use it as the frame of an actual organ from which cells are removed. A “living” impression can be made on him with the help of material donated by the future organ recipient. Takanori Takebe of the University of Yokohama was a pioneer in creating liver tissue using stem cells. None of these approaches are included in routine clinical practice with organs, but they are included in the production of specific tissues, opening the way to personalized bioprinting even directly into a patient’s damaged organ.