Scientists have printed complex biological tissues on a 3D printer

A group of scientists developed a unique 3D printer, thanks to which it became possible to print materials that are as close as possible to their living tissues. Already, with their help, you can study various types of cancer, without fear of damaging patients.

Living fabrics are incredibly complex structures, so the creation of their artificial versions requires delicate work and cooperation of many specialists. Scientists hope that a 3D printer specially adapted for “live” printing will help them to develop new generation biomaterials. The ability to create tissues, even remotely resembling real structures of the human body, will become a real breakthrough in medicine and, in particular, virtually rid scientists of the need to test new techniques and drugs on living beings.

Ali Khademhosseini of UCLA, who led the new study, said in a press release that the new approach involves the development of new biocompatible structures from various materials. The 3D printer has two key features that make it unique. Firstly, it is a custom-made chip that controls the flow of fluids inside the microchannels. It is divided into several sectors, each of which is responsible for printing from a specific material. Secondly, this is a complex array of more than a million tiny mirrors, each of which can rotate independently of the others.

A mirror system is necessary for a process known as “automated stereolithographic bioprinting.” Micromirrors direct light onto the printed surface, forming the light contours of the three-dimensional object. But light is needed not only to create contours: UV radiation provokes a change in molecular bonds in materials, which leads to their transformation: hydrogels from liquid and semi-liquid states instantly harden, forming the necessary structure.

Hademhosseini told that his group successfully tested four different substances for printing, but in practice, a 3D printer can use any other. Tests began with simple geometric figures, but gradually scientists increased the complexity of objects, causing the machine to print fragments of muscle and connective tissues. When this part of the experiment was crowned with success, the researchers created an imitation tumor with a network of blood vessels – a very difficult task for a modern 3D printer. Already now the resulting tissue can be used as biomodels for studying various types of cancer.