Background insights

Tissue-engineered implants, bio-robotic organs, AI-enabled organ software and organoids prefacing a future revolution in ‘whole organ engineering’ and regenerative medicine are a new frontier in bionic innovation set to change the lives of road accident survivors and those suffering with chronic diseases.

End-stage organ failure is a leading cause of mortality around the world and trauma-induced organ damage is not uncommon. The need for novel therapies to treat patients with end-stage organ failure is very high. While the science behind many types of bionic implants and future options for engineered organs is still developing, this is a very exciting frontier of bionics discovery and innovation.

The last ten years has seen great progress in tissue engineering and biofabrication and the decade ahead will see wider surgical use of 3D bio-printed bone and tissue plus new bio-robotic organs and AI-enabled organ software.

While bionics once focused almost exclusively on electronic or artificially engineered body parts and treatments using external synthetic therapies, we are now in the era of ‘auto-bionics’ where integration of bionics and regeneration of human functionality, replacement of diseased organs and enhancement is our aspiration.

The ‘holy grail’ in this area is the future potential to use bionic or bioengineered organs in place of donor organ transplantation.

Top-down and bottom-up approaches to engineering organs are being explored. The top-down approach involves the use of biofabricated scaffolds seeded by cells that enable 3D tissue and a whole organ to form. In contrast, a bottom-up approach uses small portions of native tissue as building blocks so the interaction of cells with each other and their surroundings is controlled.

The ability to 3D-bioprint and have scaffolds seeded with living cells is the most talked about bottom-up approach. However, stem cell engineering that enables a single building block to be used to create organoids or organ-specific tissue is seen by some to be the most likely pathway to replace today’s organ transplant process. While organoids are used to produce models of disease and to test drugs, some are viewed as data gathering and ‘idea-forming’ for bionic organs of the future.

The distinction between standard 3D printing and bioprinting of scaffolds (for regenerative medicine) is important. 3D bioprinting uses cell-laden bio-inks and other biologics to construct a living tissue while traditional applications of 3D printing are prostheses and implants that mostly consist of inert materials.

Progress in bone engineering has been aided by the rise of additive manufacturing where scaffolds are manufactured in a number of different biodegradable materials. With traditional tissue engineering, porous ceramic or polymeric scaffolds are used to fabricate an engineered bone. Bioprinting means complex bone structures can be produced, with multiple types of cells suspended in a hydrogel that is arranged to form a biomimetic bone construct. The methods and the use of biodegradable scaffolds could see the reconstruction of lost tissues and replacement of sizeable bone defects in the future.

Alongside regenerative medicine, there is also a high level of interest in implantable biorobotic organs (IBROs) which integrate with the body by sensing in-body signals and acting to regulate biological and metabolic processes. These are different to pacemakers and neurostimulators that don’t have the ability to adjust how they operate in line with the body’s needs. Some examples of implantable bio-robotics are soft ventricular assistive devices, assisted tissue growth systems, drug delivery systems and implantable insulin.

With the growth of AI-enabled organ software (plus new regulatory mechanisms for software as a medical device), implanted biorobotic devices will need to clearly define their sensing, controlling, and performing actions (such as drug delivery). Enabling the person with the implant to still have a level of autonomy will be an important consideration for this technology to advance. Smart recharging, drug refilling strategies, and novel technologies to deliver safe and efficient miniature devices are still needed.

For more insights, refer to Implantable Biorobotic Organs (Menciassi & Iacovacci, 2020).