A technique from Case Western Reserve University seeks to address two challenges inherent in brain-implantation technology; gaging the property changes that occur during implantation and measuring on a micro-scale. 

The authors seek to make some progress down the bioengineering path — crafting a device that can withstand the physiological conditions in the brain for the long-term. 

"We created an instrument to measure the mechanical properties of micro-scale biomedical implants, after being explanted from living animals," explained principal investigator, Dr. Jeffrey R. Capadona. By preserving the changing properties that occurred during implantation even after removal, the technique offers potential to create and test new materials for brain implant devices. It could result in producing longer lasting and better suited devices for the highly-tailored functions. 

A method for environmentally-controlled microtensile testing of mechanically-adaptive polymer nanocomposites for ex-vivo characterization. Credit: The Journal of Visualized Experiments

For implanted devices, withstanding the high-temperatures, moisture, and other in-vivo properties poses a challenge to longevity. Resulting changes in stiffness, etc, of an implanted material can trigger a greater inflammatory response. "Often, the body's reaction to those implants causes the device to prematurely fail," says Capadona, "In some cases, the patient requires regular brain surgery to replace or revise the implants."

New implantation materials may help find solutions to restore motor function in individuals who have suffered from spinal cord injuries, stroke or multiple sclerosis.

"Microelectrodes embedded chronically in the brain could hold promise for using neural activity to restore motor function in individuals who have, suffered from spinal cord injuries," said Capadona.

They say their method allows for measurement of mechanical properties using microsize scales. Previous methods typically require large or nano-sized samples of material, and data has to be scaled, which doesn't always work.

When asked why they published in JoVE,
said, "We choose JoVE because of the novel format to show readers visually what we are doing. If a picture is worth [a] thousand words, a video is worth a million."

Unfortunately, they require you to buy a subscription to view more than the first 20 seconds of the 11:38 piece, so a video is worth just about 3% of a million. However, they put it in their press release

The method for the environmentally-controlled microtensile testing of mechanically-adaptive polymer nanocomposites for ex-vivo characterization. Video clip: The Journal of Visualized Experiments.

Citation: Allison E. Hess, Kelsey A. Potter, Dustin J. Tyler, Christian A. Zorman, Jeffrey R. Capadona, 'Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization', J. Vis. Exp. (78), e50078, doi:10.3791/50078 (2013).