Researchers Fabricate a Biodegradable Electronic Blood Vessel

October 12, 2020 by Luke James

Researchers in China and Switzerland have developed electrically-conductive artificial blood vessels that could replace diseased organic vessels.

Recent advances in bioelectronics hold great promise for addressing current challenges in the field of biomedicine. Recent works by a Chinese-Swiss joint research team could pave the way for even more innovation in the field. 

In research recently published in the journal Matter, the team describes an electronic blood vessel that can integrate flexible electronics with three layers of blood-vessel cells to mimic and even go beyond its organic counterpart.


Fabricating the Electronic Blood Vessel

To create the vessel, which the researchers say has excellent biocompatibility in the vascular system, they rolled up a PLC-based MPC membrane using a polytetrafluoroethylene (PTFE) mandrel.


Snapshots of the electronic blood vessel
Snapshots of the electronic blood vessel (A) and the MPC-PLC membrane (B). Relative resistance changes with a bend of 180° for 1,000 cycles (C). Image used courtesy of Matter

By surrounding electrically conductive liquid metal-polymer circuits with poly(L-lactide-co-ϵ-caprolactone), the researchers created flexible and biodegradable electrical circuitry, and this was well distributed within the three-dimensional tubular structure. 

According to the research paper, the MPC circuit is highly conductive and achieves a range of around 8 × 103 S cm−1, with the relative resistance change remaining constant after around 1,000 cycles of bending and rubbing.

To fabricate the MPC-PLC membrane, the researchers screen-printed conductive ink onto a polyethylene terephthalate (PET) membrane. According to the manufacturers of the PLC membrane, it’s projected to degrade entirely within one to two years of deployment. 


Overcoming the Inflammation Response

Although artificial vessels above 6 millimeters in diameter are widely available, things get challenging when it comes to smaller ones.

That’s because the interplay between smaller vessels and blood flow tends to trigger an inflammatory response, causing the walls of the natural vessels to cut off blood flow, says Xingyu Jiang, a biomedical engineer at the Southern University of Science and Technology in Shenzhen, China, and researcher working on the project. 


In situ monitoring of the electronic blood vessel in a rabbit

In situ monitoring of the electronic blood vessel in a rabbit. Image used courtesy of Xingyu Jiang et al.

To overcome this problem, Jiang and colleagues developed the electronic vessel using the above method to not only fabricate the components but also combine them with living cells.

After encapsulating the circuits made from the liquid metal-polymer in poly(L-lactide-co-ϵ-caprolactone), the researchers deposited layers of human blood vessel cells onto the sheets before rolling them up into their final tubular form. 


Future Applications: Gene Therapy, Biometric Sensing, and AI Health Analysis

During experiments, electrical stimulation prompted the growth and migration of the blood vessel cells deposited in the tubes’ interior walls. This supports the growth of new blood vessels, the researchers say, which could help wounds heal. In addition, the electrical fields generated by the vessels could make cell membranes more permeable, giving them potential utility in gene therapy. 


 Electronic blood vessel

Electronic blood vessel. Image used courtesy of Xingyu Jiang et al.


In the future, the researchers hope to include sensors in their electronic vessel technology so that data on blood pressure, sugar levels, and other metrics can be gathered. The researchers say that artificial intelligence could even be used, paving the way for advanced patient health monitoring and analytical tools for better patient care and earlier intervention.