Researchers use humanoid robots to grow human tendon tissue

Researchers around the world have struggled for years to create human tendon tissue with the right elasticity required for use in a human patient. To solve this conundrum, researchers have attempted to increase elasticity by building devices that stretch and bend the tissue as it grows.

But alas, these efforts have failed to produce tissue that can twist and stretch to the degree that real tissue can. That’s why this team conceived of a new approach to this difficult task.

They got rid of the conventional method of cultivating tendon tissue in boxes with devices that pull on it. Instead, the researchers deiced to actually grow it in a way that mimics the real human approach.

To do this, they conceived of a fabricated joint that mimics a human shoulder made from a modified open-source robot developed by engineers at Devanthro. This system allowed for the addition of a bioreactor and a means to attach the new tissue as it grows.

The team strategically placed bioreactor and hair-like filaments on the robot’s shoulder and then proceeded to flood pertinent areas with nutrients to stimulate growth. The cells were then given a two-week period to develop.

During that time, the shoulder would be activated for 30 minutes each day by being bent and twisted in human-like ways. The end result was a tissue that was dramatically different than that grown in a static system.

An improvement?

But is this new tissue growing method a real improvement on traditional methods? The researchers say more work needs to be done to determine that. If they do, however, manage to produce human-like tissue, the applications would be limitless.

The approach is not entirely new. In fact, it dates back more than two years ago.

In 2018, University of Tokyo researchers introduced a new “biohybrid” robot that was a crossover between living tissue and robotics, integrating biohybrid robotics with living muscle tissue grown from the cells of a rat.

The biohybrid robot was engineered to someday be used to replace missing appendages on humans, should the technology be repeated and replicated with human tissue, and to build far more advanced and lifelike robots. Are we entering a new era where robots and humans merge (or at least parts of them do)? Only time will tell.

The new study was published in the journal Communications Engineering.

Abstract: 

For more than 20 years, robotic bioreactor systems have facilitated the growth of tissue-engineered constructs using mechanical stimulation. However, we are still unable to produce functional grafts that can translate into clinical use. Humanoid robots offer the prospect of providing physiologically-relevant mechanical stimulation to grafts and implants, which may expedite their clinical deployment. To investigate the feasibility of a humanoid bioreactor, we have designed a flexible bioreactor chamber that can be attached to a modified musculoskeletal (MSK) humanoid robot shoulder joint. We demonstrate that fibroblast cells can be grown in this chamber while undergoing physiological adduction-abduction on the robotic arm. A preliminary evaluation of the transcriptome of the cells after 14 days indicated a clear influence of the loading regime on the gene expression profile. These early results will facilitate the exploration of MSK humanoid robots as a biomechanically more realistic platform for tissue engineering and biomaterial testing applications.