New method could ease the transition of medical technology from laboratory to market
Advances in materials, microfabrication and medical imaging are accelerating the pace of innovation in implantable neuroprostheses. These flexible and biocompatible devices, which rely on electrical stimulation of the nervous system, have shown enormous potential to improve the quality of life of patients with various conditions such as paralysis and deafness. Despite their promise, most of these groundbreaking discoveries never make it out of the lab.
Few discoveries arrive on the market
Researchers tend to underestimate the amount of engineering and development work required to get a discovery out of the lab and use it in the clinic.
These discoveries can be so far ahead of the curve that it is virtually impossible to find an industrial partner willing to do the development work. “
Stéphanie Lacour, head of the Laboratory of Soft Bioelectronic Interfaces (LSBI) at EPFL
There is often a gap between the evaluation of new implantable devices and the physical and biological reality of healthcare practice. “With a new flexible and implantable interface, you have to go through additional validation steps that do not apply to conventional implants,” adds Lacour.
The EPFL team has developed an experimental protocol to test, optimize and validate flexible and personalized implants such as the devices developed by LSBI researchers. The method, which should facilitate the transition from laboratory to market, is described in an article published in the journal Advanced materials.
A four-step process
The first step is to develop a personalized, anatomically precise biophysical prototype of the tissue in which the device will be implanted. This process is made possible by medical imaging data and 3D printing techniques. “This means that, for each patient, we reproduce the precise structure of the tissue that will ultimately host the implant,” explains Giuseppe Schiavone, scientist at LSBI.
Then the manufacturing process is optimized to ensure that it is both reliable and repeatable. The soft implant is inserted into the prototype tissue, which is then placed in an environment that mimics the biophysical conditions inside the human body. Using a laboratory-developed biomimetic platform, researchers apply mechanical stimuli to the implant and surrounding tissues to mimic the dynamic environment in vivo and validate the biocompatibility and therapeutic efficacy of the device. The platform also ages the implant physically and electrochemically under near-realistic conditions.
Development through testing
“With this method, we are able to test implants more quickly, realistically and at a lower cost without the need for surgical interventions,” adds Schiavone. “And because we evaluate the device every step of the way, we can refine and improve it on the fly with minimal disruption.” According to Schiavone, the lack of standardized validation processes for soft and biocompatible implants means that research teams are currently developing their own protocols.
LSBI researchers worked with Marco Capogrosso’s group at the University of Friborg and teams from EPFL and Lausanne University Hospital (CHUV) led by Grégoire Courtine and Jocelyne Bloch to test the protocol on e-dura, a neuromodulation device developed by EPFL and implanted in the epidural space of the spinal cord.
Although these new flexible implantable devices are not yet ready for clinical trials, the authors of the article hope their work will encourage other researchers to apply translational principles and support further advances in medical innovation.
Federal Institute of Technology in Lausanne
Schiavone, G., et al. (2020) Flexible and implantable bioelectronic interfaces for translational research. Advanced materials. doi.org/10.1002/adma.201906512.